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 * Checks if ack is a congestion control event.
499 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
500 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
502 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
503 * defined to be 'duplicate' */
504 *is_dack = tc->sack_sb.last_sacked_bytes
505 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
507 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
511 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
513 sack_scoreboard_hole_t *next, *prev;
515 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
517 next = pool_elt_at_index (sb->holes, hole->next);
518 next->prev = hole->prev;
522 sb->tail = hole->prev;
525 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
527 prev = pool_elt_at_index (sb->holes, hole->prev);
528 prev->next = hole->next;
532 sb->head = hole->next;
535 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
536 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
538 /* Poison the entry */
540 memset (hole, 0xfe, sizeof (*hole));
542 pool_put (sb->holes, hole);
545 sack_scoreboard_hole_t *
546 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
549 sack_scoreboard_hole_t *hole, *next, *prev;
552 pool_get (sb->holes, hole);
553 memset (hole, 0, sizeof (*hole));
557 hole_index = scoreboard_hole_index (sb, hole);
559 prev = scoreboard_get_hole (sb, prev_index);
562 hole->prev = prev_index;
563 hole->next = prev->next;
565 if ((next = scoreboard_next_hole (sb, hole)))
566 next->prev = hole_index;
568 sb->tail = hole_index;
570 prev->next = hole_index;
574 sb->head = hole_index;
575 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
576 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
583 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
585 sack_scoreboard_hole_t *hole, *prev;
586 u32 bytes = 0, blks = 0;
589 sb->sacked_bytes = 0;
590 hole = scoreboard_last_hole (sb);
594 if (seq_gt (sb->high_sacked, hole->end))
596 bytes = sb->high_sacked - hole->end;
600 while ((prev = scoreboard_prev_hole (sb, hole))
601 && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
602 && blks < TCP_DUPACK_THRESHOLD))
604 bytes += hole->start - prev->end;
611 sb->lost_bytes += scoreboard_hole_bytes (hole);
614 hole = scoreboard_prev_hole (sb, hole);
616 bytes += prev->start - hole->end;
618 sb->sacked_bytes = bytes;
622 * Figure out the next hole to retransmit
624 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
626 sack_scoreboard_hole_t *
627 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
628 sack_scoreboard_hole_t * start,
630 u8 * can_rescue, u8 * snd_limited)
632 sack_scoreboard_hole_t *hole = 0;
634 hole = start ? start : scoreboard_first_hole (sb);
635 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
636 hole = scoreboard_next_hole (sb, hole);
638 /* Nothing, return */
641 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
645 /* Rule (1): if higher than rxt, less than high_sacked and lost */
646 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
648 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
652 /* Rule (2): output takes care of transmitting new data */
653 if (!have_sent_1_smss)
656 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
658 /* Rule (3): if hole not lost */
659 else if (seq_lt (hole->start, sb->high_sacked))
662 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
664 /* Rule (4): if hole beyond high_sacked */
667 ASSERT (seq_geq (hole->start, sb->high_sacked));
670 /* HighRxt MUST NOT be updated */
675 if (hole && seq_lt (sb->high_rxt, hole->start))
676 sb->high_rxt = hole->start;
682 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
684 sack_scoreboard_hole_t *hole;
685 hole = scoreboard_first_hole (sb);
688 seq = seq_gt (seq, hole->start) ? seq : hole->start;
689 sb->cur_rxt_hole = sb->head;
695 * Test that scoreboard is sane after recovery
697 * Returns 1 if scoreboard is empty or if first hole beyond
701 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
703 sack_scoreboard_hole_t *hole;
704 hole = scoreboard_first_hole (&tc->sack_sb);
705 return (!hole || seq_geq (hole->start, tc->snd_una));
709 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
711 sack_scoreboard_t *sb = &tc->sack_sb;
712 sack_block_t *blk, tmp;
713 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
714 u32 blk_index = 0, old_sacked_bytes, hole_index;
717 sb->last_sacked_bytes = 0;
719 old_sacked_bytes = sb->sacked_bytes;
720 sb->last_bytes_delivered = 0;
722 if (!tcp_opts_sack (&tc->rcv_opts)
723 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
726 /* Remove invalid blocks */
727 blk = tc->rcv_opts.sacks;
728 while (blk < vec_end (tc->rcv_opts.sacks))
730 if (seq_lt (blk->start, blk->end)
731 && seq_gt (blk->start, tc->snd_una)
732 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
737 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
740 /* Add block for cumulative ack */
741 if (seq_gt (ack, tc->snd_una))
743 tmp.start = tc->snd_una;
745 vec_add1 (tc->rcv_opts.sacks, tmp);
748 if (vec_len (tc->rcv_opts.sacks) == 0)
751 tcp_scoreboard_trace_add (tc, ack);
753 /* Make sure blocks are ordered */
754 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
755 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
756 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
758 tmp = tc->rcv_opts.sacks[i];
759 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
760 tc->rcv_opts.sacks[j] = tmp;
763 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
765 /* If no holes, insert the first that covers all outstanding bytes */
766 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
767 tc->snd_una, tc->snd_una_max);
768 sb->tail = scoreboard_hole_index (sb, last_hole);
769 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
770 sb->high_sacked = tmp.end;
774 /* If we have holes but snd_una_max is beyond the last hole, update
776 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
777 last_hole = scoreboard_last_hole (sb);
778 if (seq_gt (tc->snd_una_max, last_hole->end))
780 if (seq_geq (last_hole->start, sb->high_sacked))
782 last_hole->end = tc->snd_una_max;
784 /* New hole after high sacked block */
785 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
787 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
791 /* Keep track of max byte sacked for when the last hole
793 if (seq_gt (tmp.end, sb->high_sacked))
794 sb->high_sacked = tmp.end;
797 /* Walk the holes with the SACK blocks */
798 hole = pool_elt_at_index (sb->holes, sb->head);
799 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
801 blk = &tc->rcv_opts.sacks[blk_index];
802 if (seq_leq (blk->start, hole->start))
804 /* Block covers hole. Remove hole */
805 if (seq_geq (blk->end, hole->end))
807 next_hole = scoreboard_next_hole (sb, hole);
809 /* Byte accounting: snd_una needs to be advanced */
814 if (seq_lt (ack, next_hole->start))
815 sb->snd_una_adv = next_hole->start - ack;
816 sb->last_bytes_delivered +=
817 next_hole->start - hole->end;
821 ASSERT (seq_geq (sb->high_sacked, ack));
822 sb->snd_una_adv = sb->high_sacked - ack;
823 sb->last_bytes_delivered += sb->high_sacked - hole->end;
827 scoreboard_remove_hole (sb, hole);
830 /* Partial 'head' overlap */
833 if (seq_gt (blk->end, hole->start))
835 hole->start = blk->end;
842 /* Hole must be split */
843 if (seq_lt (blk->end, hole->end))
845 hole_index = scoreboard_hole_index (sb, hole);
846 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
849 /* Pool might've moved */
850 hole = scoreboard_get_hole (sb, hole_index);
851 hole->end = blk->start;
853 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
855 else if (seq_lt (blk->start, hole->end))
857 hole->end = blk->start;
859 hole = scoreboard_next_hole (sb, hole);
863 scoreboard_update_bytes (tc, sb);
864 sb->last_sacked_bytes = sb->sacked_bytes
865 - (old_sacked_bytes - sb->last_bytes_delivered);
866 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes);
867 ASSERT (sb->sacked_bytes == 0
868 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
869 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
870 - seq_max (tc->snd_una, ack));
871 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
872 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
876 * Try to update snd_wnd based on feedback received from peer.
878 * If successful, and new window is 'effectively' 0, activate persist
882 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
884 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
885 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
886 if (seq_lt (tc->snd_wl1, seq)
887 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
889 tc->snd_wnd = snd_wnd;
892 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
894 if (tc->snd_wnd < tc->snd_mss)
896 /* Set persist timer if not set and we just got 0 wnd */
897 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
898 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
899 tcp_persist_timer_set (tc);
903 tcp_persist_timer_reset (tc);
904 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
914 tcp_cc_init_congestion (tcp_connection_t * tc)
916 tcp_fastrecovery_on (tc);
917 tc->snd_congestion = tc->snd_una_max;
918 tc->cc_algo->congestion (tc);
919 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
923 tcp_cc_recovery_exit (tcp_connection_t * tc)
929 tcp_recovery_off (tc);
933 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
935 tc->cc_algo->recovered (tc);
936 tc->snd_rxt_bytes = 0;
938 tcp_fastrecovery_off (tc);
939 tcp_fastrecovery_1_smss_off (tc);
943 tcp_cc_congestion_undo (tcp_connection_t * tc)
945 tc->cwnd = tc->prev_cwnd;
946 tc->ssthresh = tc->prev_ssthresh;
947 tc->snd_nxt = tc->snd_una_max;
949 if (tcp_in_recovery (tc))
950 tcp_cc_recovery_exit (tc);
951 ASSERT (tc->rto_boff == 0);
952 /* TODO extend for fastrecovery */
956 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
958 return (tcp_in_recovery (tc)
960 && tcp_opts_tstamp (&tc->rcv_opts)
961 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
965 tcp_cc_recover (tcp_connection_t * tc)
967 ASSERT (tcp_in_cong_recovery (tc));
968 if (tcp_cc_is_spurious_retransmit (tc))
970 tcp_cc_congestion_undo (tc);
974 if (tcp_in_recovery (tc))
975 tcp_cc_recovery_exit (tc);
976 else if (tcp_in_fastrecovery (tc))
977 tcp_cc_fastrecovery_exit (tc);
979 ASSERT (tc->rto_boff == 0);
980 ASSERT (!tcp_in_cong_recovery (tc));
981 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
982 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
987 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
989 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
991 /* Congestion avoidance */
992 tc->cc_algo->rcv_ack (tc);
993 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
995 /* If a cumulative ack, make sure dupacks is 0 */
998 /* When dupacks hits the threshold we only enter fast retransmit if
999 * cumulative ack covers more than snd_congestion. Should snd_una
1000 * wrap this test may fail under otherwise valid circumstances.
1001 * Therefore, proactively update snd_congestion when wrap detected. */
1003 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1004 && seq_gt (tc->snd_congestion, tc->snd_una)))
1005 tc->snd_congestion = tc->snd_una - 1;
1009 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1011 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1015 tcp_should_fastrecover (tcp_connection_t * tc)
1017 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1018 || tcp_should_fastrecover_sack (tc));
1022 * One function to rule them all ... and in the darkness bind them
1025 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1030 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1031 * it account for the bytes that left the network.
1035 ASSERT (tc->snd_una != tc->snd_una_max
1036 || tc->sack_sb.last_sacked_bytes);
1040 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1042 ASSERT (tcp_in_fastrecovery (tc));
1043 /* Pure duplicate ack. If some data got acked, it's handled lower */
1044 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1047 else if (tcp_should_fastrecover (tc))
1049 /* Things are already bad */
1050 if (tcp_in_cong_recovery (tc))
1052 tc->rcv_dupacks = 0;
1053 goto partial_ack_test;
1056 /* If of of the two conditions lower hold, reset dupacks because
1057 * we're probably after timeout (RFC6582 heuristics).
1058 * If Cumulative ack does not cover more than congestion threshold,
1060 * 1) The following doesn't hold: The congestion window is greater
1061 * than SMSS bytes and the difference between highest_ack
1062 * and prev_highest_ack is at most 4*SMSS bytes
1063 * 2) Echoed timestamp in the last non-dup ack does not equal the
1066 if (seq_leq (tc->snd_una, tc->snd_congestion)
1067 && ((!(tc->cwnd > tc->snd_mss
1068 && tc->bytes_acked <= 4 * tc->snd_mss))
1069 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1071 tc->rcv_dupacks = 0;
1075 tcp_cc_init_congestion (tc);
1076 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1078 /* The first segment MUST be retransmitted */
1079 tcp_retransmit_first_unacked (tc);
1081 /* Post retransmit update cwnd to ssthresh and account for the
1082 * three segments that have left the network and should've been
1083 * buffered at the receiver XXX */
1084 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1085 ASSERT (tc->cwnd >= tc->snd_mss);
1087 /* If cwnd allows, send more data */
1088 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1090 scoreboard_init_high_rxt (&tc->sack_sb,
1091 tc->snd_una + tc->snd_mss);
1092 tcp_fast_retransmit_sack (tc);
1096 tcp_fast_retransmit_no_sack (tc);
1101 else if (!tc->bytes_acked
1102 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1104 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1113 if (!tc->bytes_acked)
1118 * Legitimate ACK. 1) See if we can exit recovery
1120 /* XXX limit this only to first partial ack? */
1121 tcp_retransmit_timer_update (tc);
1123 if (seq_geq (tc->snd_una, tc->snd_congestion))
1125 /* If spurious return, we've already updated everything */
1126 if (tcp_cc_recover (tc))
1128 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1132 tc->snd_nxt = tc->snd_una_max;
1134 /* Treat as congestion avoidance ack */
1135 tc->cc_algo->rcv_ack (tc);
1136 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1141 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1143 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1145 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1146 * reset dupacks to 0 */
1147 tc->rcv_dupacks = 0;
1149 tcp_retransmit_first_unacked (tc);
1151 /* Post RTO timeout don't try anything fancy */
1152 if (tcp_in_recovery (tc))
1155 /* Remove retransmitted bytes that have been delivered */
1156 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1157 >= tc->sack_sb.last_bytes_delivered
1158 || (tc->flags & TCP_CONN_FINSNT));
1160 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1162 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1163 * remove sacked bytes delivered */
1164 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1165 - tc->sack_sb.last_bytes_delivered;
1166 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1167 tc->snd_rxt_bytes -= rxt_delivered;
1171 /* Either all retransmitted holes have been acked, or we're
1172 * "in the blind" and retransmitting segment by segment */
1173 tc->snd_rxt_bytes = 0;
1176 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1179 * Since this was a partial ack, try to retransmit some more data
1181 tcp_fast_retransmit (tc);
1185 tcp_cc_init (tcp_connection_t * tc)
1187 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
1188 tc->cc_algo->init (tc);
1192 * Process incoming ACK
1195 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1196 tcp_header_t * th, u32 * next, u32 * error)
1198 u32 prev_snd_wnd, prev_snd_una;
1201 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1203 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1204 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1206 /* If we have outstanding data and this is within the window, accept it,
1207 * probably retransmit has timed out. Otherwise ACK segment and then
1209 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1211 tcp_make_ack (tc, b);
1212 *next = tcp_next_output (tc->c_is_ip4);
1213 *error = TCP_ERROR_ACK_INVALID;
1214 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1215 vnet_buffer (b)->tcp.ack_number);
1219 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1220 vnet_buffer (b)->tcp.ack_number);
1222 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1223 *error = TCP_ERROR_ACK_FUTURE;
1226 /* If old ACK, probably it's an old dupack */
1227 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1229 *error = TCP_ERROR_ACK_OLD;
1230 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1231 vnet_buffer (b)->tcp.ack_number);
1232 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1234 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
1235 tcp_cc_handle_event (tc, 1);
1237 /* Don't drop yet */
1242 * Looks okay, process feedback
1245 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1246 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1248 prev_snd_wnd = tc->snd_wnd;
1249 prev_snd_una = tc->snd_una;
1250 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1251 vnet_buffer (b)->tcp.ack_number,
1252 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1253 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1254 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1255 tcp_validate_txf_size (tc, tc->bytes_acked);
1257 if (tc->bytes_acked)
1258 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1260 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1263 * Check if we have congestion event
1266 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1268 tcp_cc_handle_event (tc, is_dack);
1269 if (!tcp_in_cong_recovery (tc))
1271 *error = TCP_ERROR_ACK_DUP;
1272 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1273 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1277 * Update congestion control (slow start/congestion avoidance)
1279 tcp_cc_update (tc, b);
1285 tcp_sack_vector_is_sane (sack_block_t * sacks)
1288 for (i = 1; i < vec_len (sacks); i++)
1290 if (sacks[i - 1].end == sacks[i].start)
1297 * Build SACK list as per RFC2018.
1299 * Makes sure the first block contains the segment that generated the current
1300 * ACK and the following ones are the ones most recently reported in SACK
1303 * @param tc TCP connection for which the SACK list is updated
1304 * @param start Start sequence number of the newest SACK block
1305 * @param end End sequence of the newest SACK block
1308 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1310 sack_block_t *new_list = 0, *block = 0;
1313 /* If the first segment is ooo add it to the list. Last write might've moved
1314 * rcv_nxt over the first segment. */
1315 if (seq_lt (tc->rcv_nxt, start))
1317 vec_add2 (new_list, block, 1);
1318 block->start = start;
1322 /* Find the blocks still worth keeping. */
1323 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1325 /* Discard if rcv_nxt advanced beyond current block */
1326 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1329 /* Merge or drop if segment overlapped by the new segment */
1330 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1331 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1333 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1334 new_list[0].start = tc->snd_sacks[i].start;
1335 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1336 new_list[0].end = tc->snd_sacks[i].end;
1340 /* Save to new SACK list if we have space. */
1341 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1343 vec_add1 (new_list, tc->snd_sacks[i]);
1347 clib_warning ("sack discarded");
1351 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1353 /* Replace old vector with new one */
1354 vec_free (tc->snd_sacks);
1355 tc->snd_sacks = new_list;
1357 /* Segments should not 'touch' */
1358 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1361 /** Enqueue data for delivery to application */
1363 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1366 int written, error = TCP_ERROR_ENQUEUED;
1368 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1370 /* Pure ACK. Update rcv_nxt and be done. */
1371 if (PREDICT_FALSE (data_len == 0))
1373 return TCP_ERROR_PURE_ACK;
1376 written = stream_session_enqueue_data (&tc->connection, b, 0,
1377 1 /* queue event */ , 1);
1379 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1381 /* Update rcv_nxt */
1382 if (PREDICT_TRUE (written == data_len))
1384 tc->rcv_nxt += written;
1386 /* If more data written than expected, account for out-of-order bytes. */
1387 else if (written > data_len)
1389 tc->rcv_nxt += written;
1391 /* Send ACK confirming the update */
1392 tc->flags |= TCP_CONN_SNDACK;
1394 else if (written > 0)
1396 /* We've written something but FIFO is probably full now */
1397 tc->rcv_nxt += written;
1399 /* Depending on how fast the app is, all remaining buffers in burst will
1400 * not be enqueued. Inform peer */
1401 tc->flags |= TCP_CONN_SNDACK;
1403 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1407 tc->flags |= TCP_CONN_SNDACK;
1408 return TCP_ERROR_FIFO_FULL;
1411 /* Update SACK list if need be */
1412 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1414 /* Remove SACK blocks that have been delivered */
1415 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1421 /** Enqueue out-of-order data */
1423 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1426 stream_session_t *s0;
1429 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1431 /* Pure ACK. Do nothing */
1432 if (PREDICT_FALSE (data_len == 0))
1434 return TCP_ERROR_PURE_ACK;
1437 /* Enqueue out-of-order data with relative offset */
1438 rv = stream_session_enqueue_data (&tc->connection, b,
1439 vnet_buffer (b)->tcp.seq_number -
1440 tc->rcv_nxt, 0 /* queue event */ , 0);
1442 /* Nothing written */
1445 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1446 return TCP_ERROR_FIFO_FULL;
1449 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1451 /* Update SACK list if in use */
1452 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1454 ooo_segment_t *newest;
1457 s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
1459 /* Get the newest segment from the fifo */
1460 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1463 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1464 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1465 start = tc->rcv_nxt + offset;
1466 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1467 tcp_update_sack_list (tc, start, end);
1468 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1472 return TCP_ERROR_ENQUEUED;
1476 * Check if ACK could be delayed. If ack can be delayed, it should return
1477 * true for a full frame. If we're always acking return 0.
1480 tcp_can_delack (tcp_connection_t * tc)
1482 /* Send ack if ... */
1484 /* just sent a rcv wnd 0 */
1485 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1486 /* constrained to send ack */
1487 || (tc->flags & TCP_CONN_SNDACK) != 0
1488 /* we're almost out of tx wnd */
1489 || tcp_available_snd_space (tc) < 4 * tc->snd_mss)
1496 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1498 u32 discard, first = b->current_length;
1499 vlib_main_t *vm = vlib_get_main ();
1501 /* Handle multi-buffer segments */
1502 if (n_bytes_to_drop > b->current_length)
1504 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1508 discard = clib_min (n_bytes_to_drop, b->current_length);
1509 vlib_buffer_advance (b, discard);
1510 b = vlib_get_buffer (vm, b->next_buffer);
1511 n_bytes_to_drop -= discard;
1513 while (n_bytes_to_drop);
1514 if (n_bytes_to_drop > first)
1515 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1518 vlib_buffer_advance (b, n_bytes_to_drop);
1519 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1524 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1527 u32 error = 0, n_bytes_to_drop, n_data_bytes;
1529 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1530 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1531 ASSERT (n_data_bytes);
1533 /* Handle out-of-order data */
1534 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1536 /* Old sequence numbers allowed through because they overlapped
1538 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1540 error = TCP_ERROR_SEGMENT_OLD;
1541 *next0 = TCP_NEXT_DROP;
1543 /* Completely in the past (possible retransmit) */
1544 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1546 /* Ack retransmissions since we may not have any data to send */
1547 tcp_make_ack (tc, b);
1548 *next0 = tcp_next_output (tc->c_is_ip4);
1552 /* Chop off the bytes in the past */
1553 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1554 n_data_bytes -= n_bytes_to_drop;
1555 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1556 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1562 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1564 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1565 * cwnd on remote peer when congested 2) acks leaving should have the
1566 * latest rcv_wnd since the burst may eaten up all of it, so only the
1567 * old ones could be filtered.
1570 /* RFC2581: Send DUPACK for fast retransmit */
1571 tcp_make_ack (tc, b);
1572 *next0 = tcp_next_output (tc->c_is_ip4);
1574 /* Mark as DUPACK. We may filter these in output if
1575 * the burst fills the holes. */
1577 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1579 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1585 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1586 * segments can be enqueued after fifo tail offset changes. */
1587 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1589 /* Check if ACK can be delayed */
1590 if (tcp_can_delack (tc))
1592 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1593 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1597 *next0 = tcp_next_output (tc->c_is_ip4);
1598 tcp_make_ack (tc, b);
1606 tcp_header_t tcp_header;
1607 tcp_connection_t tcp_connection;
1611 format_tcp_rx_trace (u8 * s, va_list * args)
1613 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1614 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1615 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1616 uword indent = format_get_indent (s);
1618 s = format (s, "%U\n%U%U",
1619 format_tcp_header, &t->tcp_header, 128,
1620 format_white_space, indent,
1621 format_tcp_connection, &t->tcp_connection, 1);
1627 format_tcp_rx_trace_short (u8 * s, va_list * args)
1629 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1630 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1631 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1633 s = format (s, "%d -> %d (%U)",
1634 clib_net_to_host_u16 (t->tcp_header.src_port),
1635 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1636 t->tcp_connection.state);
1642 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1643 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1647 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1651 th0 = tcp_buffer_hdr (b0);
1653 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1657 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1659 if (PREDICT_TRUE (!val))
1663 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1665 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1669 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1670 vlib_frame_t * from_frame, int is_ip4)
1672 u32 n_left_from, next_index, *from, *to_next;
1673 u32 my_thread_index = vm->thread_index, errors = 0;
1674 tcp_main_t *tm = vnet_get_tcp_main ();
1677 from = vlib_frame_vector_args (from_frame);
1678 n_left_from = from_frame->n_vectors;
1680 next_index = node->cached_next_index;
1682 while (n_left_from > 0)
1686 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1687 while (n_left_from > 0 && n_left_to_next > 0)
1691 tcp_header_t *th0 = 0;
1692 tcp_connection_t *tc0;
1693 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1700 n_left_to_next -= 1;
1702 b0 = vlib_get_buffer (vm, bi0);
1703 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1706 if (PREDICT_FALSE (tc0 == 0))
1708 error0 = TCP_ERROR_INVALID_CONNECTION;
1712 th0 = tcp_buffer_hdr (b0);
1713 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1714 * dangling reference. */
1715 is_fin = tcp_is_fin (th0);
1717 /* SYNs, FINs and data consume sequence numbers */
1718 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1719 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1721 /* TODO header prediction fast path */
1723 /* 1-4: check SEQ, RST, SYN */
1724 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1726 error0 = TCP_ERROR_SEGMENT_INVALID;
1727 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1728 vnet_buffer (b0)->tcp.seq_number,
1729 vnet_buffer (b0)->tcp.seq_end);
1733 /* 5: check the ACK field */
1734 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1737 /* 6: check the URG bit TODO */
1739 /* 7: process the segment text */
1740 if (vnet_buffer (b0)->tcp.data_len)
1741 error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
1743 /* 8: check the FIN bit */
1744 if (PREDICT_FALSE (is_fin))
1746 /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
1747 * wait for session to call close. To avoid lingering
1748 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1749 tc0->state = TCP_STATE_CLOSE_WAIT;
1750 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1751 if (vnet_buffer (b0)->tcp.data_len == 0)
1754 next0 = TCP_ESTABLISHED_NEXT_DROP;
1756 stream_session_disconnect_notify (&tc0->connection);
1757 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1761 b0->error = node->errors[error0];
1762 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1764 tcp_rx_trace_t *t0 =
1765 vlib_add_trace (vm, node, b0, sizeof (*t0));
1766 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1769 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1770 n_left_to_next, bi0, next0);
1773 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1776 errors = session_manager_flush_enqueue_events (my_thread_index);
1777 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1778 tcp_flush_frame_to_output (vm, my_thread_index, is_ip4);
1780 return from_frame->n_vectors;
1784 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1785 vlib_frame_t * from_frame)
1787 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1791 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1792 vlib_frame_t * from_frame)
1794 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1798 VLIB_REGISTER_NODE (tcp4_established_node) =
1800 .function = tcp4_established,
1801 .name = "tcp4-established",
1802 /* Takes a vector of packets. */
1803 .vector_size = sizeof (u32),
1804 .n_errors = TCP_N_ERROR,
1805 .error_strings = tcp_error_strings,
1806 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1809 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1810 foreach_tcp_state_next
1813 .format_trace = format_tcp_rx_trace_short,
1817 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1820 VLIB_REGISTER_NODE (tcp6_established_node) =
1822 .function = tcp6_established,
1823 .name = "tcp6-established",
1824 /* Takes a vector of packets. */
1825 .vector_size = sizeof (u32),
1826 .n_errors = TCP_N_ERROR,
1827 .error_strings = tcp_error_strings,
1828 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1831 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1832 foreach_tcp_state_next
1835 .format_trace = format_tcp_rx_trace_short,
1840 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1842 vlib_node_registration_t tcp4_syn_sent_node;
1843 vlib_node_registration_t tcp6_syn_sent_node;
1846 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1847 vlib_frame_t * from_frame, int is_ip4)
1849 tcp_main_t *tm = vnet_get_tcp_main ();
1850 u32 n_left_from, next_index, *from, *to_next;
1851 u32 my_thread_index = vm->thread_index, errors = 0;
1853 from = vlib_frame_vector_args (from_frame);
1854 n_left_from = from_frame->n_vectors;
1856 next_index = node->cached_next_index;
1858 while (n_left_from > 0)
1862 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1864 while (n_left_from > 0 && n_left_to_next > 0)
1866 u32 bi0, ack0, seq0;
1869 tcp_header_t *tcp0 = 0;
1870 tcp_connection_t *tc0;
1871 tcp_connection_t *new_tc0;
1872 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1879 n_left_to_next -= 1;
1881 b0 = vlib_get_buffer (vm, bi0);
1883 tcp_half_open_connection_get (vnet_buffer (b0)->
1884 tcp.connection_index);
1885 if (PREDICT_FALSE (tc0 == 0))
1887 error0 = TCP_ERROR_INVALID_CONNECTION;
1891 ack0 = vnet_buffer (b0)->tcp.ack_number;
1892 seq0 = vnet_buffer (b0)->tcp.seq_number;
1893 tcp0 = tcp_buffer_hdr (b0);
1896 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1899 /* SYNs, FINs and data consume sequence numbers */
1900 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1901 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
1904 * 1. check the ACK bit
1908 * If the ACK bit is set
1909 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
1910 * the RST bit is set, if so drop the segment and return)
1911 * <SEQ=SEG.ACK><CTL=RST>
1912 * and discard the segment. Return.
1913 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
1917 if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt)
1919 if (!tcp_rst (tcp0))
1920 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
1924 /* Make sure ACK is valid */
1925 if (tc0->snd_una > ack0)
1930 * 2. check the RST bit
1935 /* If ACK is acceptable, signal client that peer is not
1936 * willing to accept connection and drop connection*/
1938 tcp_connection_reset (tc0);
1943 * 3. check the security and precedence (skipped)
1947 * 4. check the SYN bit
1950 /* No SYN flag. Drop. */
1951 if (!tcp_syn (tcp0))
1955 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
1958 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
1959 * current thread pool. */
1960 pool_get (tm->connections[my_thread_index], new_tc0);
1961 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
1962 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
1963 new_tc0->c_thread_index = my_thread_index;
1964 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
1965 new_tc0->irs = seq0;
1966 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
1967 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
1968 TCP_TIMER_HANDLE_INVALID;
1970 /* If this is not the owning thread, wait for syn retransmit to
1971 * expire and cleanup then */
1972 if (tcp_half_open_connection_cleanup (tc0))
1973 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
1975 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
1977 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
1978 new_tc0->tsval_recent_age = tcp_time_now ();
1981 if (tcp_opts_wscale (&new_tc0->rcv_opts))
1982 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
1984 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
1985 << new_tc0->snd_wscale;
1986 new_tc0->snd_wl1 = seq0;
1987 new_tc0->snd_wl2 = ack0;
1989 tcp_connection_init_vars (new_tc0);
1991 /* SYN-ACK: See if we can switch to ESTABLISHED state */
1992 if (PREDICT_TRUE (tcp_ack (tcp0)))
1994 /* Our SYN is ACKed: we have iss < ack = snd_una */
1996 /* TODO Dequeue acknowledged segments if we support Fast Open */
1997 new_tc0->snd_una = ack0;
1998 new_tc0->state = TCP_STATE_ESTABLISHED;
2000 /* Make sure las is initialized for the wnd computation */
2001 new_tc0->rcv_las = new_tc0->rcv_nxt;
2003 /* Notify app that we have connection. If session layer can't
2004 * allocate session send reset */
2005 if (stream_session_connect_notify (&new_tc0->connection, 0))
2007 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2008 tcp_connection_cleanup (new_tc0);
2012 /* Make sure after data segment processing ACK is sent */
2013 new_tc0->flags |= TCP_CONN_SNDACK;
2015 /* Update rtt with the syn-ack sample */
2016 new_tc0->bytes_acked = 1;
2017 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2018 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2020 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2023 new_tc0->state = TCP_STATE_SYN_RCVD;
2025 /* Notify app that we have connection */
2026 if (stream_session_connect_notify (&new_tc0->connection, 0))
2028 tcp_connection_cleanup (new_tc0);
2029 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2030 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2035 tcp_make_synack (new_tc0, b0);
2036 next0 = tcp_next_output (is_ip4);
2041 /* Read data, if any */
2042 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2045 error0 = tcp_segment_rcv (tm, new_tc0, b0, &next0);
2046 if (error0 == TCP_ERROR_PURE_ACK)
2047 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2051 tcp_make_ack (new_tc0, b0);
2052 next0 = tcp_next_output (new_tc0->c_is_ip4);
2057 b0->error = error0 ? node->errors[error0] : 0;
2058 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2060 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2061 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2062 clib_memcpy (&t0->tcp_connection, tc0,
2063 sizeof (t0->tcp_connection));
2066 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2067 n_left_to_next, bi0, next0);
2070 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2073 errors = session_manager_flush_enqueue_events (my_thread_index);
2077 vlib_node_increment_counter (vm, tcp4_established_node.index,
2078 TCP_ERROR_EVENT_FIFO_FULL, errors);
2080 vlib_node_increment_counter (vm, tcp6_established_node.index,
2081 TCP_ERROR_EVENT_FIFO_FULL, errors);
2084 return from_frame->n_vectors;
2088 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2089 vlib_frame_t * from_frame)
2091 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2095 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2096 vlib_frame_t * from_frame)
2098 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2102 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2104 .function = tcp4_syn_sent,
2105 .name = "tcp4-syn-sent",
2106 /* Takes a vector of packets. */
2107 .vector_size = sizeof (u32),
2108 .n_errors = TCP_N_ERROR,
2109 .error_strings = tcp_error_strings,
2110 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2113 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2114 foreach_tcp_state_next
2117 .format_trace = format_tcp_rx_trace_short,
2121 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2124 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2126 .function = tcp6_syn_sent_rcv,
2127 .name = "tcp6-syn-sent",
2128 /* Takes a vector of packets. */
2129 .vector_size = sizeof (u32),
2130 .n_errors = TCP_N_ERROR,
2131 .error_strings = tcp_error_strings,
2132 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2135 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2136 foreach_tcp_state_next
2139 .format_trace = format_tcp_rx_trace_short,
2143 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2146 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2147 * as per RFC793 p. 64
2150 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2151 vlib_frame_t * from_frame, int is_ip4)
2153 tcp_main_t *tm = vnet_get_tcp_main ();
2154 u32 n_left_from, next_index, *from, *to_next;
2155 u32 my_thread_index = vm->thread_index, errors = 0;
2157 from = vlib_frame_vector_args (from_frame);
2158 n_left_from = from_frame->n_vectors;
2160 next_index = node->cached_next_index;
2162 while (n_left_from > 0)
2166 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2168 while (n_left_from > 0 && n_left_to_next > 0)
2172 tcp_header_t *tcp0 = 0;
2173 tcp_connection_t *tc0;
2174 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
2181 n_left_to_next -= 1;
2183 b0 = vlib_get_buffer (vm, bi0);
2184 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2186 if (PREDICT_FALSE (tc0 == 0))
2188 error0 = TCP_ERROR_INVALID_CONNECTION;
2192 tcp0 = tcp_buffer_hdr (b0);
2194 /* SYNs, FINs and data consume sequence numbers */
2195 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2196 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0)
2197 + vnet_buffer (b0)->tcp.data_len;
2200 * Special treatment for CLOSED
2204 case TCP_STATE_CLOSED:
2210 * For all other states (except LISTEN)
2213 /* 1-4: check SEQ, RST, SYN */
2215 (tcp_segment_validate (vm, tc0, b0, tcp0, &next0)))
2217 error0 = TCP_ERROR_SEGMENT_INVALID;
2221 /* 5: check the ACK field */
2224 case TCP_STATE_SYN_RCVD:
2226 * If the segment acknowledgment is not acceptable, form a
2228 * <SEQ=SEG.ACK><CTL=RST>
2231 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2233 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2237 /* Update rtt and rto */
2238 tc0->bytes_acked = 1;
2239 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2241 /* Switch state to ESTABLISHED */
2242 tc0->state = TCP_STATE_ESTABLISHED;
2244 /* Initialize session variables */
2245 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2246 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2247 << tc0->rcv_opts.wscale;
2248 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2249 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2250 stream_session_accept_notify (&tc0->connection);
2252 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2253 tcp_retransmit_timer_reset (tc0);
2254 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2256 case TCP_STATE_ESTABLISHED:
2257 /* We can get packets in established state here because they
2258 * were enqueued before state change */
2259 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2263 case TCP_STATE_FIN_WAIT_1:
2264 /* In addition to the processing for the ESTABLISHED state, if
2265 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2266 * continue processing in that state. */
2267 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2270 /* Still have to send the FIN */
2271 if (tc0->flags & TCP_CONN_FINPNDG)
2273 /* TX fifo finally drained */
2274 if (!stream_session_tx_fifo_max_dequeue (&tc0->connection))
2277 /* If FIN is ACKed */
2278 else if (tc0->snd_una == tc0->snd_una_max)
2281 tc0->state = TCP_STATE_FIN_WAIT_2;
2282 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2286 /* Stop all timers, 2MSL will be set lower */
2287 tcp_connection_timers_reset (tc0);
2291 /* Wait for peer to finish sending its data */
2292 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2297 case TCP_STATE_FIN_WAIT_2:
2298 /* In addition to the processing for the ESTABLISHED state, if
2299 * the retransmission queue is empty, the user's CLOSE can be
2300 * acknowledged ("ok") but do not delete the TCB. */
2301 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2304 case TCP_STATE_CLOSE_WAIT:
2305 /* Do the same processing as for the ESTABLISHED state. */
2306 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2309 case TCP_STATE_CLOSING:
2310 /* In addition to the processing for the ESTABLISHED state, if
2311 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2312 * otherwise ignore the segment. */
2313 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2316 tc0->state = TCP_STATE_TIME_WAIT;
2317 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2318 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2322 case TCP_STATE_LAST_ACK:
2323 /* The only thing that [should] arrive in this state is an
2324 * acknowledgment of our FIN. If our FIN is now acknowledged,
2325 * delete the TCB, enter the CLOSED state, and return. */
2327 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2330 /* Apparently our FIN was lost */
2333 /* Don't "make" fin since that increments snd_nxt */
2338 tc0->state = TCP_STATE_CLOSED;
2339 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2341 /* Don't delete the connection/session yet. Instead, wait a
2342 * reasonable amount of time until the pipes are cleared. In
2343 * particular, this makes sure that we won't have dead sessions
2344 * when processing events on the tx path */
2345 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2347 /* Stop retransmit */
2348 tcp_retransmit_timer_reset (tc0);
2353 case TCP_STATE_TIME_WAIT:
2354 /* The only thing that can arrive in this state is a
2355 * retransmission of the remote FIN. Acknowledge it, and restart
2356 * the 2 MSL timeout. */
2358 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2361 tcp_make_ack (tc0, b0);
2362 tcp_timer_reset (tc0, TCP_TIMER_WAITCLOSE);
2363 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2372 /* 6: check the URG bit TODO */
2374 /* 7: process the segment text */
2377 case TCP_STATE_ESTABLISHED:
2378 case TCP_STATE_FIN_WAIT_1:
2379 case TCP_STATE_FIN_WAIT_2:
2380 if (vnet_buffer (b0)->tcp.data_len)
2381 error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
2383 case TCP_STATE_CLOSE_WAIT:
2384 case TCP_STATE_CLOSING:
2385 case TCP_STATE_LAST_ACK:
2386 case TCP_STATE_TIME_WAIT:
2387 /* This should not occur, since a FIN has been received from the
2388 * remote side. Ignore the segment text. */
2392 /* 8: check the FIN bit */
2393 if (!tcp_fin (tcp0))
2398 case TCP_STATE_ESTABLISHED:
2399 case TCP_STATE_SYN_RCVD:
2400 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2401 tcp_connection_timers_reset (tc0);
2402 tcp_make_fin (tc0, b0);
2403 next0 = tcp_next_output (tc0->c_is_ip4);
2404 stream_session_disconnect_notify (&tc0->connection);
2405 tc0->state = TCP_STATE_CLOSE_WAIT;
2406 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2408 case TCP_STATE_CLOSE_WAIT:
2409 case TCP_STATE_CLOSING:
2410 case TCP_STATE_LAST_ACK:
2413 case TCP_STATE_FIN_WAIT_1:
2414 tc0->state = TCP_STATE_CLOSING;
2415 tcp_make_ack (tc0, b0);
2416 next0 = tcp_next_output (is_ip4);
2417 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2418 /* Wait for ACK but not forever */
2419 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2421 case TCP_STATE_FIN_WAIT_2:
2422 /* Got FIN, send ACK! */
2423 tc0->state = TCP_STATE_TIME_WAIT;
2424 tcp_connection_timers_reset (tc0);
2425 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2426 tcp_make_ack (tc0, b0);
2427 next0 = tcp_next_output (is_ip4);
2428 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2430 case TCP_STATE_TIME_WAIT:
2431 /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
2434 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2437 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2440 b0->error = error0 ? node->errors[error0] : 0;
2442 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2444 tcp_rx_trace_t *t0 =
2445 vlib_add_trace (vm, node, b0, sizeof (*t0));
2446 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2449 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2450 n_left_to_next, bi0, next0);
2453 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2456 errors = session_manager_flush_enqueue_events (my_thread_index);
2460 vlib_node_increment_counter (vm, tcp4_established_node.index,
2461 TCP_ERROR_EVENT_FIFO_FULL, errors);
2463 vlib_node_increment_counter (vm, tcp6_established_node.index,
2464 TCP_ERROR_EVENT_FIFO_FULL, errors);
2467 return from_frame->n_vectors;
2471 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2472 vlib_frame_t * from_frame)
2474 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2478 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2479 vlib_frame_t * from_frame)
2481 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2485 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2487 .function = tcp4_rcv_process,
2488 .name = "tcp4-rcv-process",
2489 /* Takes a vector of packets. */
2490 .vector_size = sizeof (u32),
2491 .n_errors = TCP_N_ERROR,
2492 .error_strings = tcp_error_strings,
2493 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2496 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2497 foreach_tcp_state_next
2500 .format_trace = format_tcp_rx_trace_short,
2504 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2507 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2509 .function = tcp6_rcv_process,
2510 .name = "tcp6-rcv-process",
2511 /* Takes a vector of packets. */
2512 .vector_size = sizeof (u32),
2513 .n_errors = TCP_N_ERROR,
2514 .error_strings = tcp_error_strings,
2515 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2518 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2519 foreach_tcp_state_next
2522 .format_trace = format_tcp_rx_trace_short,
2526 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2528 vlib_node_registration_t tcp4_listen_node;
2529 vlib_node_registration_t tcp6_listen_node;
2532 * LISTEN state processing as per RFC 793 p. 65
2535 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2536 vlib_frame_t * from_frame, int is_ip4)
2538 u32 n_left_from, next_index, *from, *to_next;
2539 u32 my_thread_index = vm->thread_index;
2540 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
2542 from = vlib_frame_vector_args (from_frame);
2543 n_left_from = from_frame->n_vectors;
2545 next_index = node->cached_next_index;
2547 while (n_left_from > 0)
2551 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2553 while (n_left_from > 0 && n_left_to_next > 0)
2558 tcp_header_t *th0 = 0;
2559 tcp_connection_t *lc0;
2562 tcp_connection_t *child0;
2563 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2570 n_left_to_next -= 1;
2572 b0 = vlib_get_buffer (vm, bi0);
2573 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2577 ip40 = vlib_buffer_get_current (b0);
2578 th0 = ip4_next_header (ip40);
2582 ip60 = vlib_buffer_get_current (b0);
2583 th0 = ip6_next_header (ip60);
2586 /* Create child session. For syn-flood protection use filter */
2588 /* 1. first check for an RST: handled in dispatch */
2589 /* if (tcp_rst (th0))
2592 /* 2. second check for an ACK: handled in dispatch */
2593 /* if (tcp_ack (th0))
2595 tcp_send_reset (b0, is_ip4);
2599 /* 3. check for a SYN (did that already) */
2601 /* Create child session and send SYN-ACK */
2602 child0 = tcp_connection_new (my_thread_index);
2603 child0->c_lcl_port = lc0->c_lcl_port;
2604 child0->c_rmt_port = th0->src_port;
2605 child0->c_is_ip4 = is_ip4;
2606 child0->state = TCP_STATE_SYN_RCVD;
2610 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2611 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2615 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2616 sizeof (ip6_address_t));
2617 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2618 sizeof (ip6_address_t));
2621 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2624 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2628 if (tcp_options_parse (th0, &child0->rcv_opts))
2633 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2634 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2635 child0->rcv_las = child0->rcv_nxt;
2637 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2638 * segments are used to initialize PAWS. */
2639 if (tcp_opts_tstamp (&child0->rcv_opts))
2641 child0->tsval_recent = child0->rcv_opts.tsval;
2642 child0->tsval_recent_age = tcp_time_now ();
2645 if (tcp_opts_wscale (&child0->rcv_opts))
2646 child0->snd_wscale = child0->rcv_opts.wscale;
2648 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2649 << child0->snd_wscale;
2650 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2651 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2653 tcp_connection_init_vars (child0);
2654 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0);
2656 /* Reuse buffer to make syn-ack and send */
2657 tcp_make_synack (child0, b0);
2658 next0 = tcp_next_output (is_ip4);
2659 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
2662 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2664 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2665 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2666 clib_memcpy (&t0->tcp_connection, lc0,
2667 sizeof (t0->tcp_connection));
2670 b0->error = node->errors[error0];
2672 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2673 n_left_to_next, bi0, next0);
2676 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2678 return from_frame->n_vectors;
2682 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2683 vlib_frame_t * from_frame)
2685 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2689 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2690 vlib_frame_t * from_frame)
2692 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2696 VLIB_REGISTER_NODE (tcp4_listen_node) =
2698 .function = tcp4_listen,
2699 .name = "tcp4-listen",
2700 /* Takes a vector of packets. */
2701 .vector_size = sizeof (u32),
2702 .n_errors = TCP_N_ERROR,
2703 .error_strings = tcp_error_strings,
2704 .n_next_nodes = TCP_LISTEN_N_NEXT,
2707 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2708 foreach_tcp_state_next
2711 .format_trace = format_tcp_rx_trace_short,
2715 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2718 VLIB_REGISTER_NODE (tcp6_listen_node) =
2720 .function = tcp6_listen,
2721 .name = "tcp6-listen",
2722 /* Takes a vector of packets. */
2723 .vector_size = sizeof (u32),
2724 .n_errors = TCP_N_ERROR,
2725 .error_strings = tcp_error_strings,
2726 .n_next_nodes = TCP_LISTEN_N_NEXT,
2729 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2730 foreach_tcp_state_next
2733 .format_trace = format_tcp_rx_trace_short,
2737 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2739 vlib_node_registration_t tcp4_input_node;
2740 vlib_node_registration_t tcp6_input_node;
2742 typedef enum _tcp_input_next
2744 TCP_INPUT_NEXT_DROP,
2745 TCP_INPUT_NEXT_LISTEN,
2746 TCP_INPUT_NEXT_RCV_PROCESS,
2747 TCP_INPUT_NEXT_SYN_SENT,
2748 TCP_INPUT_NEXT_ESTABLISHED,
2749 TCP_INPUT_NEXT_RESET,
2753 #define foreach_tcp4_input_next \
2754 _ (DROP, "error-drop") \
2755 _ (LISTEN, "tcp4-listen") \
2756 _ (RCV_PROCESS, "tcp4-rcv-process") \
2757 _ (SYN_SENT, "tcp4-syn-sent") \
2758 _ (ESTABLISHED, "tcp4-established") \
2759 _ (RESET, "tcp4-reset")
2761 #define foreach_tcp6_input_next \
2762 _ (DROP, "error-drop") \
2763 _ (LISTEN, "tcp6-listen") \
2764 _ (RCV_PROCESS, "tcp6-rcv-process") \
2765 _ (SYN_SENT, "tcp6-syn-sent") \
2766 _ (ESTABLISHED, "tcp6-established") \
2767 _ (RESET, "tcp6-reset")
2769 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2772 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2774 transport_connection_t *tmp;
2778 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2779 && (tc->state == TCP_STATE_LISTEN
2780 || tc->c_rmt_port == hdr->src_port));
2785 stream_session_half_open_lookup (&tc->c_lcl_ip, &tc->c_rmt_ip,
2786 tc->c_lcl_port, tc->c_rmt_port,
2787 tc->c_transport_proto)))
2789 if (tmp->lcl_port == hdr->dst_port
2790 && tmp->rmt_port == hdr->src_port)
2792 clib_warning ("half-open is valid!");
2800 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2801 vlib_frame_t * from_frame, int is_ip4)
2803 u32 n_left_from, next_index, *from, *to_next;
2804 u32 my_thread_index = vm->thread_index;
2805 tcp_main_t *tm = vnet_get_tcp_main ();
2807 from = vlib_frame_vector_args (from_frame);
2808 n_left_from = from_frame->n_vectors;
2809 next_index = node->cached_next_index;
2810 tcp_set_time_now (my_thread_index);
2812 while (n_left_from > 0)
2816 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2818 while (n_left_from > 0 && n_left_to_next > 0)
2820 int n_advance_bytes0, n_data_bytes0;
2823 tcp_header_t *tcp0 = 0;
2824 tcp_connection_t *tc0;
2827 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2835 n_left_to_next -= 1;
2837 b0 = vlib_get_buffer (vm, bi0);
2838 vnet_buffer (b0)->tcp.flags = 0;
2840 /* Checksum computed by ipx_local no need to compute again */
2844 ip40 = vlib_buffer_get_current (b0);
2845 tcp0 = ip4_next_header (ip40);
2846 n_advance_bytes0 = (ip4_header_bytes (ip40)
2847 + tcp_header_bytes (tcp0));
2848 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2852 (tcp_connection_t *)
2853 stream_session_lookup_transport_wt4 (&ip40->dst_address,
2857 SESSION_TYPE_IP4_TCP,
2859 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
2863 ip60 = vlib_buffer_get_current (b0);
2864 tcp0 = ip6_next_header (ip60);
2865 n_advance_bytes0 = tcp_header_bytes (tcp0);
2866 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2868 n_advance_bytes0 += sizeof (ip60[0]);
2871 (tcp_connection_t *)
2872 stream_session_lookup_transport_wt6 (&ip60->dst_address,
2876 SESSION_TYPE_IP6_TCP,
2878 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
2882 if (PREDICT_FALSE (n_advance_bytes0 < 0))
2884 error0 = TCP_ERROR_LENGTH;
2888 /* Session exists */
2889 if (PREDICT_TRUE (0 != tc0))
2891 /* Save connection index */
2892 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2893 vnet_buffer (b0)->tcp.seq_number =
2894 clib_net_to_host_u32 (tcp0->seq_number);
2895 vnet_buffer (b0)->tcp.ack_number =
2896 clib_net_to_host_u32 (tcp0->ack_number);
2898 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
2899 - (u8 *) vlib_buffer_get_current (b0);
2900 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
2901 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
2903 flags0 = tcp0->flags & filter_flags;
2904 next0 = tm->dispatch_table[tc0->state][flags0].next;
2905 error0 = tm->dispatch_table[tc0->state][flags0].error;
2907 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH
2908 || next0 == TCP_INPUT_NEXT_RESET))
2910 /* Overload tcp flags to store state */
2911 tcp_state_t state0 = tc0->state;
2912 vnet_buffer (b0)->tcp.flags = tc0->state;
2914 if (error0 == TCP_ERROR_DISPATCH)
2915 clib_warning ("disp error state %U flags %U",
2916 format_tcp_state, state0, format_tcp_flags,
2923 next0 = TCP_INPUT_NEXT_RESET;
2924 error0 = TCP_ERROR_NO_LISTENER;
2928 b0->error = error0 ? node->errors[error0] : 0;
2930 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2932 tcp_rx_trace_t *t0 =
2933 vlib_add_trace (vm, node, b0, sizeof (*t0));
2934 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2936 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2937 n_left_to_next, bi0, next0);
2940 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2943 return from_frame->n_vectors;
2947 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2948 vlib_frame_t * from_frame)
2950 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2954 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2955 vlib_frame_t * from_frame)
2957 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2961 VLIB_REGISTER_NODE (tcp4_input_node) =
2963 .function = tcp4_input,
2964 .name = "tcp4-input",
2965 /* Takes a vector of packets. */
2966 .vector_size = sizeof (u32),
2967 .n_errors = TCP_N_ERROR,
2968 .error_strings = tcp_error_strings,
2969 .n_next_nodes = TCP_INPUT_N_NEXT,
2972 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2973 foreach_tcp4_input_next
2976 .format_buffer = format_tcp_header,
2977 .format_trace = format_tcp_rx_trace,
2981 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
2984 VLIB_REGISTER_NODE (tcp6_input_node) =
2986 .function = tcp6_input,
2987 .name = "tcp6-input",
2988 /* Takes a vector of packets. */
2989 .vector_size = sizeof (u32),
2990 .n_errors = TCP_N_ERROR,
2991 .error_strings = tcp_error_strings,
2992 .n_next_nodes = TCP_INPUT_N_NEXT,
2995 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2996 foreach_tcp6_input_next
2999 .format_buffer = format_tcp_header,
3000 .format_trace = format_tcp_rx_trace,
3004 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3007 tcp_dispatch_table_init (tcp_main_t * tm)
3010 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3011 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3013 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3014 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3017 #define _(t,f,n,e) \
3019 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3020 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3023 /* SYNs for new connections -> tcp-listen. */
3024 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3025 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3026 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_NONE);
3027 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3029 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3030 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3031 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3032 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3033 /* SYN-ACK for a SYN */
3034 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3036 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3037 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3038 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3040 /* ACK for for established connection -> tcp-established. */
3041 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3042 /* FIN for for established connection -> tcp-established. */
3043 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3044 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3046 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3047 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3049 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3050 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3052 /* ACK or FIN-ACK to our FIN */
3053 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3054 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3056 /* FIN in reply to our FIN from the other side */
3057 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3058 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3059 /* FIN confirming that the peer (app) has closed */
3060 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3061 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3062 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3064 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3065 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3067 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3068 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3069 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3071 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3072 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3073 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3075 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3076 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3077 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_CONNECTION_CLOSED);
3078 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3079 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3080 TCP_ERROR_CONNECTION_CLOSED);
3085 tcp_input_init (vlib_main_t * vm)
3087 clib_error_t *error = 0;
3088 tcp_main_t *tm = vnet_get_tcp_main ();
3090 if ((error = vlib_call_init_function (vm, tcp_init)))
3093 /* Initialize dispatch table. */
3094 tcp_dispatch_table_init (tm);
3099 VLIB_INIT_FUNCTION (tcp_input_init);
3102 * fd.io coding-style-patch-verification: ON
3105 * eval: (c-set-style "gnu")