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,
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 = vnet_buffer (b)->tcp.seq_end;
1386 /* If more data written than expected, account for out-of-order bytes. */
1387 else if (written > data_len)
1389 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end + written - data_len;
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 return 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);
1418 return TCP_ERROR_ENQUEUED;
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)
1499 vlib_main_t *vm = vlib_get_main ();
1501 /* Handle multi segment packets */
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);
1519 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1522 u32 error = 0, n_bytes_to_drop, n_data_bytes;
1524 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1525 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1526 ASSERT (n_data_bytes);
1528 /* Handle out-of-order data */
1529 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1531 /* Old sequence numbers allowed through because they overlapped
1533 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1535 error = TCP_ERROR_SEGMENT_OLD;
1536 *next0 = TCP_NEXT_DROP;
1538 /* Completely in the past (possible retransmit) */
1539 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1541 /* Ack retransmissions since we may not have any data to send */
1542 tcp_make_ack (tc, b);
1543 *next0 = tcp_next_output (tc->c_is_ip4);
1547 /* Chop off the bytes in the past */
1548 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1549 n_data_bytes -= n_bytes_to_drop;
1550 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1551 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1557 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1559 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1560 * cwnd on remote peer when congested 2) acks leaving should have the
1561 * latest rcv_wnd since the burst may eaten up all of it, so only the
1562 * old ones could be filtered.
1565 /* RFC2581: Send DUPACK for fast retransmit */
1566 tcp_make_ack (tc, b);
1567 *next0 = tcp_next_output (tc->c_is_ip4);
1569 /* Mark as DUPACK. We may filter these in output if
1570 * the burst fills the holes. */
1572 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1574 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1580 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1581 * segments can be enqueued after fifo tail offset changes. */
1582 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1584 /* Check if ACK can be delayed */
1585 if (tcp_can_delack (tc))
1587 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1588 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1592 *next0 = tcp_next_output (tc->c_is_ip4);
1593 tcp_make_ack (tc, b);
1601 tcp_header_t tcp_header;
1602 tcp_connection_t tcp_connection;
1606 format_tcp_rx_trace (u8 * s, va_list * args)
1608 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1609 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1610 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1611 uword indent = format_get_indent (s);
1613 s = format (s, "%U\n%U%U",
1614 format_tcp_header, &t->tcp_header, 128,
1615 format_white_space, indent,
1616 format_tcp_connection, &t->tcp_connection, 1);
1622 format_tcp_rx_trace_short (u8 * s, va_list * args)
1624 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1625 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1626 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1628 s = format (s, "%d -> %d (%U)",
1629 clib_net_to_host_u16 (t->tcp_header.src_port),
1630 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1631 t->tcp_connection.state);
1637 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1638 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1642 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1646 th0 = tcp_buffer_hdr (b0);
1648 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1652 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1654 if (PREDICT_TRUE (!val))
1658 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1660 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1664 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1665 vlib_frame_t * from_frame, int is_ip4)
1667 u32 n_left_from, next_index, *from, *to_next;
1668 u32 my_thread_index = vm->thread_index, errors = 0;
1669 tcp_main_t *tm = vnet_get_tcp_main ();
1672 from = vlib_frame_vector_args (from_frame);
1673 n_left_from = from_frame->n_vectors;
1675 next_index = node->cached_next_index;
1677 while (n_left_from > 0)
1681 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1682 while (n_left_from > 0 && n_left_to_next > 0)
1686 tcp_header_t *th0 = 0;
1687 tcp_connection_t *tc0;
1688 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1695 n_left_to_next -= 1;
1697 b0 = vlib_get_buffer (vm, bi0);
1698 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1701 if (PREDICT_FALSE (tc0 == 0))
1703 error0 = TCP_ERROR_INVALID_CONNECTION;
1707 th0 = tcp_buffer_hdr (b0);
1708 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1709 * dangling reference. */
1710 is_fin = tcp_is_fin (th0);
1712 /* SYNs, FINs and data consume sequence numbers */
1713 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1714 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1716 /* TODO header prediction fast path */
1718 /* 1-4: check SEQ, RST, SYN */
1719 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1721 error0 = TCP_ERROR_SEGMENT_INVALID;
1722 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1723 vnet_buffer (b0)->tcp.seq_number,
1724 vnet_buffer (b0)->tcp.seq_end);
1728 /* 5: check the ACK field */
1729 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1732 /* 6: check the URG bit TODO */
1734 /* 7: process the segment text */
1735 if (vnet_buffer (b0)->tcp.data_len)
1736 error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
1738 /* 8: check the FIN bit */
1739 if (PREDICT_FALSE (is_fin))
1741 /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
1742 * wait for session to call close. To avoid lingering
1743 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1744 tc0->state = TCP_STATE_CLOSE_WAIT;
1745 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1746 if (vnet_buffer (b0)->tcp.data_len == 0)
1749 next0 = TCP_ESTABLISHED_NEXT_DROP;
1751 stream_session_disconnect_notify (&tc0->connection);
1752 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1756 b0->error = node->errors[error0];
1757 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1759 tcp_rx_trace_t *t0 =
1760 vlib_add_trace (vm, node, b0, sizeof (*t0));
1761 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1764 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1765 n_left_to_next, bi0, next0);
1768 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1771 errors = session_manager_flush_enqueue_events (my_thread_index);
1772 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1773 tcp_flush_frame_to_output (vm, my_thread_index, is_ip4);
1775 return from_frame->n_vectors;
1779 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1780 vlib_frame_t * from_frame)
1782 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1786 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1787 vlib_frame_t * from_frame)
1789 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1793 VLIB_REGISTER_NODE (tcp4_established_node) =
1795 .function = tcp4_established,
1796 .name = "tcp4-established",
1797 /* Takes a vector of packets. */
1798 .vector_size = sizeof (u32),
1799 .n_errors = TCP_N_ERROR,
1800 .error_strings = tcp_error_strings,
1801 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1804 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1805 foreach_tcp_state_next
1808 .format_trace = format_tcp_rx_trace_short,
1812 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1815 VLIB_REGISTER_NODE (tcp6_established_node) =
1817 .function = tcp6_established,
1818 .name = "tcp6-established",
1819 /* Takes a vector of packets. */
1820 .vector_size = sizeof (u32),
1821 .n_errors = TCP_N_ERROR,
1822 .error_strings = tcp_error_strings,
1823 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1826 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1827 foreach_tcp_state_next
1830 .format_trace = format_tcp_rx_trace_short,
1835 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1837 vlib_node_registration_t tcp4_syn_sent_node;
1838 vlib_node_registration_t tcp6_syn_sent_node;
1841 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1842 vlib_frame_t * from_frame, int is_ip4)
1844 tcp_main_t *tm = vnet_get_tcp_main ();
1845 u32 n_left_from, next_index, *from, *to_next;
1846 u32 my_thread_index = vm->thread_index, errors = 0;
1848 from = vlib_frame_vector_args (from_frame);
1849 n_left_from = from_frame->n_vectors;
1851 next_index = node->cached_next_index;
1853 while (n_left_from > 0)
1857 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1859 while (n_left_from > 0 && n_left_to_next > 0)
1861 u32 bi0, ack0, seq0;
1864 tcp_header_t *tcp0 = 0;
1865 tcp_connection_t *tc0;
1866 tcp_connection_t *new_tc0;
1867 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1874 n_left_to_next -= 1;
1876 b0 = vlib_get_buffer (vm, bi0);
1878 tcp_half_open_connection_get (vnet_buffer (b0)->
1879 tcp.connection_index);
1881 ack0 = vnet_buffer (b0)->tcp.ack_number;
1882 seq0 = vnet_buffer (b0)->tcp.seq_number;
1883 tcp0 = tcp_buffer_hdr (b0);
1887 ip4_header_t *ip40 = vlib_buffer_get_current (b0);
1888 tcp0 = ip4_next_header (ip40);
1890 (tcp_connection_t *)
1891 stream_session_lookup_transport_wt4 (&ip40->dst_address,
1895 SESSION_TYPE_IP4_TCP,
1901 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1904 /* SYNs, FINs and data consume sequence numbers */
1905 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1906 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
1909 * 1. check the ACK bit
1913 * If the ACK bit is set
1914 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
1915 * the RST bit is set, if so drop the segment and return)
1916 * <SEQ=SEG.ACK><CTL=RST>
1917 * and discard the segment. Return.
1918 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
1922 if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt)
1924 if (!tcp_rst (tcp0))
1925 tcp_send_reset (tc0, b0, is_ip4);
1929 /* Make sure ACK is valid */
1930 if (tc0->snd_una > ack0)
1935 * 2. check the RST bit
1940 /* If ACK is acceptable, signal client that peer is not
1941 * willing to accept connection and drop connection*/
1943 tcp_connection_reset (tc0);
1948 * 3. check the security and precedence (skipped)
1952 * 4. check the SYN bit
1955 /* No SYN flag. Drop. */
1956 if (!tcp_syn (tcp0))
1960 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
1963 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
1964 * current thread pool. */
1965 pool_get (tm->connections[my_thread_index], new_tc0);
1966 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
1967 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
1968 new_tc0->c_thread_index = my_thread_index;
1969 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
1970 new_tc0->irs = seq0;
1971 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
1972 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
1973 TCP_TIMER_HANDLE_INVALID;
1975 /* If this is not the owning thread, wait for syn retransmit to
1976 * expire and cleanup then */
1977 if (tcp_half_open_connection_cleanup (tc0))
1978 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
1980 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
1982 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
1983 new_tc0->tsval_recent_age = tcp_time_now ();
1986 if (tcp_opts_wscale (&new_tc0->rcv_opts))
1987 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
1989 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
1990 << new_tc0->snd_wscale;
1991 new_tc0->snd_wl1 = seq0;
1992 new_tc0->snd_wl2 = ack0;
1994 tcp_connection_init_vars (new_tc0);
1996 /* SYN-ACK: See if we can switch to ESTABLISHED state */
1997 if (PREDICT_TRUE (tcp_ack (tcp0)))
1999 /* Our SYN is ACKed: we have iss < ack = snd_una */
2001 /* TODO Dequeue acknowledged segments if we support Fast Open */
2002 new_tc0->snd_una = ack0;
2003 new_tc0->state = TCP_STATE_ESTABLISHED;
2005 /* Make sure las is initialized for the wnd computation */
2006 new_tc0->rcv_las = new_tc0->rcv_nxt;
2008 /* Notify app that we have connection. If session layer can't
2009 * allocate session send reset */
2010 if (stream_session_connect_notify (&new_tc0->connection, 0))
2012 tcp_send_reset (new_tc0, b0, is_ip4);
2013 tcp_connection_cleanup (new_tc0);
2017 /* Make sure after data segment processing ACK is sent */
2018 new_tc0->flags |= TCP_CONN_SNDACK;
2020 /* Update rtt with the syn-ack sample */
2021 new_tc0->bytes_acked = 1;
2022 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2023 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2025 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2028 new_tc0->state = TCP_STATE_SYN_RCVD;
2030 /* Notify app that we have connection */
2031 if (stream_session_connect_notify (&new_tc0->connection, 0))
2033 tcp_connection_cleanup (new_tc0);
2034 tcp_send_reset (tc0, b0, is_ip4);
2035 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2040 tcp_make_synack (new_tc0, b0);
2041 next0 = tcp_next_output (is_ip4);
2046 /* Read data, if any */
2047 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2050 error0 = tcp_segment_rcv (tm, new_tc0, b0, &next0);
2051 if (error0 == TCP_ERROR_PURE_ACK)
2052 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2056 tcp_make_ack (new_tc0, b0);
2057 next0 = tcp_next_output (new_tc0->c_is_ip4);
2062 b0->error = error0 ? node->errors[error0] : 0;
2063 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2065 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2066 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2067 clib_memcpy (&t0->tcp_connection, tc0,
2068 sizeof (t0->tcp_connection));
2071 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2072 n_left_to_next, bi0, next0);
2075 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2078 errors = session_manager_flush_enqueue_events (my_thread_index);
2082 vlib_node_increment_counter (vm, tcp4_established_node.index,
2083 TCP_ERROR_EVENT_FIFO_FULL, errors);
2085 vlib_node_increment_counter (vm, tcp6_established_node.index,
2086 TCP_ERROR_EVENT_FIFO_FULL, errors);
2089 return from_frame->n_vectors;
2093 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2094 vlib_frame_t * from_frame)
2096 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2100 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2101 vlib_frame_t * from_frame)
2103 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2107 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2109 .function = tcp4_syn_sent,
2110 .name = "tcp4-syn-sent",
2111 /* Takes a vector of packets. */
2112 .vector_size = sizeof (u32),
2113 .n_errors = TCP_N_ERROR,
2114 .error_strings = tcp_error_strings,
2115 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2118 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2119 foreach_tcp_state_next
2122 .format_trace = format_tcp_rx_trace_short,
2126 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2129 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2131 .function = tcp6_syn_sent_rcv,
2132 .name = "tcp6-syn-sent",
2133 /* Takes a vector of packets. */
2134 .vector_size = sizeof (u32),
2135 .n_errors = TCP_N_ERROR,
2136 .error_strings = tcp_error_strings,
2137 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2140 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2141 foreach_tcp_state_next
2144 .format_trace = format_tcp_rx_trace_short,
2148 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2151 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2152 * as per RFC793 p. 64
2155 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2156 vlib_frame_t * from_frame, int is_ip4)
2158 tcp_main_t *tm = vnet_get_tcp_main ();
2159 u32 n_left_from, next_index, *from, *to_next;
2160 u32 my_thread_index = vm->thread_index, errors = 0;
2162 from = vlib_frame_vector_args (from_frame);
2163 n_left_from = from_frame->n_vectors;
2165 next_index = node->cached_next_index;
2167 while (n_left_from > 0)
2171 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2173 while (n_left_from > 0 && n_left_to_next > 0)
2177 tcp_header_t *tcp0 = 0;
2178 tcp_connection_t *tc0;
2179 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
2186 n_left_to_next -= 1;
2188 b0 = vlib_get_buffer (vm, bi0);
2189 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2191 if (PREDICT_FALSE (tc0 == 0))
2193 error0 = TCP_ERROR_INVALID_CONNECTION;
2197 tcp0 = tcp_buffer_hdr (b0);
2199 /* SYNs, FINs and data consume sequence numbers */
2200 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2201 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0)
2202 + vnet_buffer (b0)->tcp.data_len;
2205 * Special treatment for CLOSED
2209 case TCP_STATE_CLOSED:
2215 * For all other states (except LISTEN)
2218 /* 1-4: check SEQ, RST, SYN */
2220 (tcp_segment_validate (vm, tc0, b0, tcp0, &next0)))
2222 error0 = TCP_ERROR_SEGMENT_INVALID;
2226 /* 5: check the ACK field */
2229 case TCP_STATE_SYN_RCVD:
2231 * If the segment acknowledgment is not acceptable, form a
2233 * <SEQ=SEG.ACK><CTL=RST>
2236 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2238 tcp_send_reset (tc0, b0, is_ip4);
2242 /* Update rtt and rto */
2243 tc0->bytes_acked = 1;
2244 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2246 /* Switch state to ESTABLISHED */
2247 tc0->state = TCP_STATE_ESTABLISHED;
2249 /* Initialize session variables */
2250 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2251 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2252 << tc0->rcv_opts.wscale;
2253 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2254 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2255 stream_session_accept_notify (&tc0->connection);
2257 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2258 tcp_retransmit_timer_reset (tc0);
2259 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2261 case TCP_STATE_ESTABLISHED:
2262 /* We can get packets in established state here because they
2263 * were enqueued before state change */
2264 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2268 case TCP_STATE_FIN_WAIT_1:
2269 /* In addition to the processing for the ESTABLISHED state, if
2270 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2271 * continue processing in that state. */
2272 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2275 /* Still have to send the FIN */
2276 if (tc0->flags & TCP_CONN_FINPNDG)
2278 /* TX fifo finally drained */
2279 if (!stream_session_tx_fifo_max_dequeue (&tc0->connection))
2282 /* If FIN is ACKed */
2283 else if (tc0->snd_una == tc0->snd_una_max)
2286 tc0->state = TCP_STATE_FIN_WAIT_2;
2287 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2291 /* Stop all timers, 2MSL will be set lower */
2292 tcp_connection_timers_reset (tc0);
2296 /* Wait for peer to finish sending its data */
2297 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2302 case TCP_STATE_FIN_WAIT_2:
2303 /* In addition to the processing for the ESTABLISHED state, if
2304 * the retransmission queue is empty, the user's CLOSE can be
2305 * acknowledged ("ok") but do not delete the TCB. */
2306 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2309 case TCP_STATE_CLOSE_WAIT:
2310 /* Do the same processing as for the ESTABLISHED state. */
2311 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2314 case TCP_STATE_CLOSING:
2315 /* In addition to the processing for the ESTABLISHED state, if
2316 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2317 * otherwise ignore the segment. */
2318 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2321 tc0->state = TCP_STATE_TIME_WAIT;
2322 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2323 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2327 case TCP_STATE_LAST_ACK:
2328 /* The only thing that [should] arrive in this state is an
2329 * acknowledgment of our FIN. If our FIN is now acknowledged,
2330 * delete the TCB, enter the CLOSED state, and return. */
2332 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2335 /* Apparently our FIN was lost */
2338 /* Don't "make" fin since that increments snd_nxt */
2343 tc0->state = TCP_STATE_CLOSED;
2344 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2346 /* Don't delete the connection/session yet. Instead, wait a
2347 * reasonable amount of time until the pipes are cleared. In
2348 * particular, this makes sure that we won't have dead sessions
2349 * when processing events on the tx path */
2350 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2352 /* Stop retransmit */
2353 tcp_retransmit_timer_reset (tc0);
2358 case TCP_STATE_TIME_WAIT:
2359 /* The only thing that can arrive in this state is a
2360 * retransmission of the remote FIN. Acknowledge it, and restart
2361 * the 2 MSL timeout. */
2363 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2366 tcp_make_ack (tc0, b0);
2367 tcp_timer_reset (tc0, TCP_TIMER_WAITCLOSE);
2368 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2377 /* 6: check the URG bit TODO */
2379 /* 7: process the segment text */
2382 case TCP_STATE_ESTABLISHED:
2383 case TCP_STATE_FIN_WAIT_1:
2384 case TCP_STATE_FIN_WAIT_2:
2385 if (vnet_buffer (b0)->tcp.data_len)
2386 error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
2388 case TCP_STATE_CLOSE_WAIT:
2389 case TCP_STATE_CLOSING:
2390 case TCP_STATE_LAST_ACK:
2391 case TCP_STATE_TIME_WAIT:
2392 /* This should not occur, since a FIN has been received from the
2393 * remote side. Ignore the segment text. */
2397 /* 8: check the FIN bit */
2398 if (!tcp_fin (tcp0))
2403 case TCP_STATE_ESTABLISHED:
2404 case TCP_STATE_SYN_RCVD:
2405 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2406 tcp_connection_timers_reset (tc0);
2407 tcp_make_fin (tc0, b0);
2408 next0 = tcp_next_output (tc0->c_is_ip4);
2409 stream_session_disconnect_notify (&tc0->connection);
2410 tc0->state = TCP_STATE_CLOSE_WAIT;
2411 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2413 case TCP_STATE_CLOSE_WAIT:
2414 case TCP_STATE_CLOSING:
2415 case TCP_STATE_LAST_ACK:
2418 case TCP_STATE_FIN_WAIT_1:
2419 tc0->state = TCP_STATE_CLOSING;
2420 tcp_make_ack (tc0, b0);
2421 next0 = tcp_next_output (is_ip4);
2422 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2423 /* Wait for ACK but not forever */
2424 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2426 case TCP_STATE_FIN_WAIT_2:
2427 /* Got FIN, send ACK! */
2428 tc0->state = TCP_STATE_TIME_WAIT;
2429 tcp_connection_timers_reset (tc0);
2430 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2431 tcp_make_ack (tc0, b0);
2432 next0 = tcp_next_output (is_ip4);
2433 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2435 case TCP_STATE_TIME_WAIT:
2436 /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
2439 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2442 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2445 b0->error = error0 ? node->errors[error0] : 0;
2447 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2449 tcp_rx_trace_t *t0 =
2450 vlib_add_trace (vm, node, b0, sizeof (*t0));
2451 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2454 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2455 n_left_to_next, bi0, next0);
2458 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2461 errors = session_manager_flush_enqueue_events (my_thread_index);
2465 vlib_node_increment_counter (vm, tcp4_established_node.index,
2466 TCP_ERROR_EVENT_FIFO_FULL, errors);
2468 vlib_node_increment_counter (vm, tcp6_established_node.index,
2469 TCP_ERROR_EVENT_FIFO_FULL, errors);
2472 return from_frame->n_vectors;
2476 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2477 vlib_frame_t * from_frame)
2479 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2483 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2484 vlib_frame_t * from_frame)
2486 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2490 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2492 .function = tcp4_rcv_process,
2493 .name = "tcp4-rcv-process",
2494 /* Takes a vector of packets. */
2495 .vector_size = sizeof (u32),
2496 .n_errors = TCP_N_ERROR,
2497 .error_strings = tcp_error_strings,
2498 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2501 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2502 foreach_tcp_state_next
2505 .format_trace = format_tcp_rx_trace_short,
2509 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2512 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2514 .function = tcp6_rcv_process,
2515 .name = "tcp6-rcv-process",
2516 /* Takes a vector of packets. */
2517 .vector_size = sizeof (u32),
2518 .n_errors = TCP_N_ERROR,
2519 .error_strings = tcp_error_strings,
2520 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2523 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2524 foreach_tcp_state_next
2527 .format_trace = format_tcp_rx_trace_short,
2531 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2533 vlib_node_registration_t tcp4_listen_node;
2534 vlib_node_registration_t tcp6_listen_node;
2537 * LISTEN state processing as per RFC 793 p. 65
2540 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2541 vlib_frame_t * from_frame, int is_ip4)
2543 u32 n_left_from, next_index, *from, *to_next;
2544 u32 my_thread_index = vm->thread_index;
2545 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
2547 from = vlib_frame_vector_args (from_frame);
2548 n_left_from = from_frame->n_vectors;
2550 next_index = node->cached_next_index;
2552 while (n_left_from > 0)
2556 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2558 while (n_left_from > 0 && n_left_to_next > 0)
2563 tcp_header_t *th0 = 0;
2564 tcp_connection_t *lc0;
2567 tcp_connection_t *child0;
2568 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2575 n_left_to_next -= 1;
2577 b0 = vlib_get_buffer (vm, bi0);
2578 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2582 ip40 = vlib_buffer_get_current (b0);
2583 th0 = ip4_next_header (ip40);
2587 ip60 = vlib_buffer_get_current (b0);
2588 th0 = ip6_next_header (ip60);
2591 /* Create child session. For syn-flood protection use filter */
2593 /* 1. first check for an RST: handled in dispatch */
2594 /* if (tcp_rst (th0))
2597 /* 2. second check for an ACK: handled in dispatch */
2598 /* if (tcp_ack (th0))
2600 tcp_send_reset (b0, is_ip4);
2604 /* 3. check for a SYN (did that already) */
2606 /* Create child session and send SYN-ACK */
2607 child0 = tcp_connection_new (my_thread_index);
2608 child0->c_lcl_port = lc0->c_lcl_port;
2609 child0->c_rmt_port = th0->src_port;
2610 child0->c_is_ip4 = is_ip4;
2611 child0->state = TCP_STATE_SYN_RCVD;
2615 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2616 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2620 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2621 sizeof (ip6_address_t));
2622 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2623 sizeof (ip6_address_t));
2626 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2629 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2633 if (tcp_options_parse (th0, &child0->rcv_opts))
2638 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2639 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2640 child0->rcv_las = child0->rcv_nxt;
2642 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2643 * segments are used to initialize PAWS. */
2644 if (tcp_opts_tstamp (&child0->rcv_opts))
2646 child0->tsval_recent = child0->rcv_opts.tsval;
2647 child0->tsval_recent_age = tcp_time_now ();
2650 if (tcp_opts_wscale (&child0->rcv_opts))
2651 child0->snd_wscale = child0->rcv_opts.wscale;
2653 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2654 << child0->snd_wscale;
2655 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2656 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2658 tcp_connection_init_vars (child0);
2659 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0);
2661 /* Reuse buffer to make syn-ack and send */
2662 tcp_make_synack (child0, b0);
2663 next0 = tcp_next_output (is_ip4);
2664 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
2667 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2669 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2670 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2671 clib_memcpy (&t0->tcp_connection, lc0,
2672 sizeof (t0->tcp_connection));
2675 b0->error = node->errors[error0];
2677 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2678 n_left_to_next, bi0, next0);
2681 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2683 return from_frame->n_vectors;
2687 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2688 vlib_frame_t * from_frame)
2690 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2694 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2695 vlib_frame_t * from_frame)
2697 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2701 VLIB_REGISTER_NODE (tcp4_listen_node) =
2703 .function = tcp4_listen,
2704 .name = "tcp4-listen",
2705 /* Takes a vector of packets. */
2706 .vector_size = sizeof (u32),
2707 .n_errors = TCP_N_ERROR,
2708 .error_strings = tcp_error_strings,
2709 .n_next_nodes = TCP_LISTEN_N_NEXT,
2712 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2713 foreach_tcp_state_next
2716 .format_trace = format_tcp_rx_trace_short,
2720 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2723 VLIB_REGISTER_NODE (tcp6_listen_node) =
2725 .function = tcp6_listen,
2726 .name = "tcp6-listen",
2727 /* Takes a vector of packets. */
2728 .vector_size = sizeof (u32),
2729 .n_errors = TCP_N_ERROR,
2730 .error_strings = tcp_error_strings,
2731 .n_next_nodes = TCP_LISTEN_N_NEXT,
2734 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2735 foreach_tcp_state_next
2738 .format_trace = format_tcp_rx_trace_short,
2742 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2744 vlib_node_registration_t tcp4_input_node;
2745 vlib_node_registration_t tcp6_input_node;
2747 typedef enum _tcp_input_next
2749 TCP_INPUT_NEXT_DROP,
2750 TCP_INPUT_NEXT_LISTEN,
2751 TCP_INPUT_NEXT_RCV_PROCESS,
2752 TCP_INPUT_NEXT_SYN_SENT,
2753 TCP_INPUT_NEXT_ESTABLISHED,
2754 TCP_INPUT_NEXT_RESET,
2758 #define foreach_tcp4_input_next \
2759 _ (DROP, "error-drop") \
2760 _ (LISTEN, "tcp4-listen") \
2761 _ (RCV_PROCESS, "tcp4-rcv-process") \
2762 _ (SYN_SENT, "tcp4-syn-sent") \
2763 _ (ESTABLISHED, "tcp4-established") \
2764 _ (RESET, "tcp4-reset")
2766 #define foreach_tcp6_input_next \
2767 _ (DROP, "error-drop") \
2768 _ (LISTEN, "tcp6-listen") \
2769 _ (RCV_PROCESS, "tcp6-rcv-process") \
2770 _ (SYN_SENT, "tcp6-syn-sent") \
2771 _ (ESTABLISHED, "tcp6-established") \
2772 _ (RESET, "tcp6-reset")
2774 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2777 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2779 transport_connection_t *tmp;
2783 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2784 && (tc->state == TCP_STATE_LISTEN
2785 || tc->c_rmt_port == hdr->src_port));
2790 stream_session_half_open_lookup (&tc->c_lcl_ip, &tc->c_rmt_ip,
2791 tc->c_lcl_port, tc->c_rmt_port,
2792 tc->c_transport_proto)))
2794 if (tmp->lcl_port == hdr->dst_port
2795 && tmp->rmt_port == hdr->src_port)
2797 clib_warning ("half-open is valid!");
2805 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2806 vlib_frame_t * from_frame, int is_ip4)
2808 u32 n_left_from, next_index, *from, *to_next;
2809 u32 my_thread_index = vm->thread_index;
2810 tcp_main_t *tm = vnet_get_tcp_main ();
2812 from = vlib_frame_vector_args (from_frame);
2813 n_left_from = from_frame->n_vectors;
2814 next_index = node->cached_next_index;
2815 tcp_set_time_now (my_thread_index);
2817 while (n_left_from > 0)
2821 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2823 while (n_left_from > 0 && n_left_to_next > 0)
2825 int n_advance_bytes0, n_data_bytes0;
2828 tcp_header_t *tcp0 = 0;
2829 tcp_connection_t *tc0;
2832 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2840 n_left_to_next -= 1;
2842 b0 = vlib_get_buffer (vm, bi0);
2843 vnet_buffer (b0)->tcp.flags = 0;
2845 /* Checksum computed by ipx_local no need to compute again */
2849 ip40 = vlib_buffer_get_current (b0);
2850 tcp0 = ip4_next_header (ip40);
2851 n_advance_bytes0 = (ip4_header_bytes (ip40)
2852 + tcp_header_bytes (tcp0));
2853 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2857 (tcp_connection_t *)
2858 stream_session_lookup_transport_wt4 (&ip40->dst_address,
2862 SESSION_TYPE_IP4_TCP,
2864 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
2868 ip60 = vlib_buffer_get_current (b0);
2869 tcp0 = ip6_next_header (ip60);
2870 n_advance_bytes0 = tcp_header_bytes (tcp0);
2871 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2873 n_advance_bytes0 += sizeof (ip60[0]);
2876 (tcp_connection_t *)
2877 stream_session_lookup_transport_wt6 (&ip60->dst_address,
2881 SESSION_TYPE_IP6_TCP,
2883 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
2887 if (PREDICT_FALSE (n_advance_bytes0 < 0))
2889 error0 = TCP_ERROR_LENGTH;
2893 /* Session exists */
2894 if (PREDICT_TRUE (0 != tc0))
2896 /* Save connection index */
2897 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2898 vnet_buffer (b0)->tcp.seq_number =
2899 clib_net_to_host_u32 (tcp0->seq_number);
2900 vnet_buffer (b0)->tcp.ack_number =
2901 clib_net_to_host_u32 (tcp0->ack_number);
2903 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
2904 - (u8 *) vlib_buffer_get_current (b0);
2905 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
2906 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
2908 flags0 = tcp0->flags & filter_flags;
2909 next0 = tm->dispatch_table[tc0->state][flags0].next;
2910 error0 = tm->dispatch_table[tc0->state][flags0].error;
2912 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH
2913 || next0 == TCP_INPUT_NEXT_RESET))
2915 /* Overload tcp flags to store state */
2916 tcp_state_t state0 = tc0->state;
2917 vnet_buffer (b0)->tcp.flags = tc0->state;
2919 if (error0 == TCP_ERROR_DISPATCH)
2920 clib_warning ("disp error state %U flags %U",
2921 format_tcp_state, state0, format_tcp_flags,
2928 next0 = TCP_INPUT_NEXT_RESET;
2929 error0 = TCP_ERROR_NO_LISTENER;
2933 b0->error = error0 ? node->errors[error0] : 0;
2935 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2937 tcp_rx_trace_t *t0 =
2938 vlib_add_trace (vm, node, b0, sizeof (*t0));
2939 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2941 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2942 n_left_to_next, bi0, next0);
2945 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2948 return from_frame->n_vectors;
2952 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2953 vlib_frame_t * from_frame)
2955 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2959 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2960 vlib_frame_t * from_frame)
2962 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2966 VLIB_REGISTER_NODE (tcp4_input_node) =
2968 .function = tcp4_input,
2969 .name = "tcp4-input",
2970 /* Takes a vector of packets. */
2971 .vector_size = sizeof (u32),
2972 .n_errors = TCP_N_ERROR,
2973 .error_strings = tcp_error_strings,
2974 .n_next_nodes = TCP_INPUT_N_NEXT,
2977 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2978 foreach_tcp4_input_next
2981 .format_buffer = format_tcp_header,
2982 .format_trace = format_tcp_rx_trace,
2986 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
2989 VLIB_REGISTER_NODE (tcp6_input_node) =
2991 .function = tcp6_input,
2992 .name = "tcp6-input",
2993 /* Takes a vector of packets. */
2994 .vector_size = sizeof (u32),
2995 .n_errors = TCP_N_ERROR,
2996 .error_strings = tcp_error_strings,
2997 .n_next_nodes = TCP_INPUT_N_NEXT,
3000 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3001 foreach_tcp6_input_next
3004 .format_buffer = format_tcp_header,
3005 .format_trace = format_tcp_rx_trace,
3009 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3012 tcp_dispatch_table_init (tcp_main_t * tm)
3015 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3016 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3018 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3019 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3022 #define _(t,f,n,e) \
3024 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3025 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3028 /* SYNs for new connections -> tcp-listen. */
3029 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3030 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3031 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_NONE);
3032 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3034 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3035 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3036 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3037 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3038 /* SYN-ACK for a SYN */
3039 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3041 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3042 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3043 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3045 /* ACK for for established connection -> tcp-established. */
3046 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3047 /* FIN for for established connection -> tcp-established. */
3048 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3049 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3051 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3052 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3054 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3055 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3057 /* ACK or FIN-ACK to our FIN */
3058 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3059 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3061 /* FIN in reply to our FIN from the other side */
3062 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3063 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3064 /* FIN confirming that the peer (app) has closed */
3065 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3066 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3067 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3069 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3070 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3072 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3073 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3074 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3076 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3077 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3078 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3080 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3081 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_CONNECTION_CLOSED);
3082 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3083 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3084 TCP_ERROR_CONNECTION_CLOSED);
3089 tcp_input_init (vlib_main_t * vm)
3091 clib_error_t *error = 0;
3092 tcp_main_t *tm = vnet_get_tcp_main ();
3094 if ((error = vlib_call_init_function (vm, tcp_init)))
3097 /* Initialize dispatch table. */
3098 tcp_dispatch_table_init (tm);
3103 VLIB_INIT_FUNCTION (tcp_input_init);
3106 * fd.io coding-style-patch-verification: ON
3109 * eval: (c-set-style "gnu")