2 * Copyright (c) 2016 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #include <vppinfra/sparse_vec.h>
17 #include <vnet/tcp/tcp_packet.h>
18 #include <vnet/tcp/tcp.h>
19 #include <vnet/session/session.h>
22 static char *tcp_error_strings[] = {
23 #define tcp_error(n,s) s,
24 #include <vnet/tcp/tcp_error.def>
28 /* All TCP nodes have the same outgoing arcs */
29 #define foreach_tcp_state_next \
30 _ (DROP, "error-drop") \
31 _ (TCP4_OUTPUT, "tcp4-output") \
32 _ (TCP6_OUTPUT, "tcp6-output")
34 typedef enum _tcp_established_next
36 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
37 foreach_tcp_state_next
39 TCP_ESTABLISHED_N_NEXT,
40 } tcp_established_next_t;
42 typedef enum _tcp_rcv_process_next
44 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
45 foreach_tcp_state_next
47 TCP_RCV_PROCESS_N_NEXT,
48 } tcp_rcv_process_next_t;
50 typedef enum _tcp_syn_sent_next
52 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
53 foreach_tcp_state_next
56 } tcp_syn_sent_next_t;
58 typedef enum _tcp_listen_next
60 #define _(s,n) TCP_LISTEN_NEXT_##s,
61 foreach_tcp_state_next
66 /* Generic, state independent indices */
67 typedef enum _tcp_state_next
69 #define _(s,n) TCP_NEXT_##s,
70 foreach_tcp_state_next
75 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
76 : TCP_NEXT_TCP6_OUTPUT)
78 vlib_node_registration_t tcp4_established_node;
79 vlib_node_registration_t tcp6_established_node;
82 * Validate segment sequence number. As per RFC793:
84 * Segment Receive Test
86 * ------- ------- -------------------------------------------
87 * 0 0 SEG.SEQ = RCV.NXT
88 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
90 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
91 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
93 * This ultimately consists in checking if segment falls within the window.
94 * The one important difference compared to RFC793 is that we use rcv_las,
95 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
96 * peer's reference when computing our receive window.
99 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
100 * however, is too strict when we have retransmits. Instead we just check that
101 * the seq is not beyond the right edge and that the end of the segment is not
102 * less than the left edge.
104 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
105 * use rcv_nxt in the right edge window test instead of rcv_las.
109 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
111 return (seq_geq (end_seq, tc->rcv_las)
112 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
116 * Parse TCP header options.
118 * @param th TCP header
119 * @param to TCP options data structure to be populated
120 * @return -1 if parsing failed
123 tcp_options_parse (tcp_header_t * th, tcp_options_t * to)
126 u8 opt_len, opts_len, kind;
130 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
131 data = (const u8 *) (th + 1);
133 /* Zero out all flags but those set in SYN */
134 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE);
136 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
140 /* Get options length */
141 if (kind == TCP_OPTION_EOL)
143 else if (kind == TCP_OPTION_NOOP)
155 /* weird option length */
156 if (opt_len < 2 || opt_len > opts_len)
164 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
166 to->flags |= TCP_OPTS_FLAG_MSS;
167 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
170 case TCP_OPTION_WINDOW_SCALE:
171 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
173 to->flags |= TCP_OPTS_FLAG_WSCALE;
174 to->wscale = data[2];
175 if (to->wscale > TCP_MAX_WND_SCALE)
177 clib_warning ("Illegal window scaling value: %d",
179 to->wscale = TCP_MAX_WND_SCALE;
183 case TCP_OPTION_TIMESTAMP:
184 if (opt_len == TCP_OPTION_LEN_TIMESTAMP)
186 to->flags |= TCP_OPTS_FLAG_TSTAMP;
187 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
188 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
191 case TCP_OPTION_SACK_PERMITTED:
192 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
193 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
195 case TCP_OPTION_SACK_BLOCK:
196 /* If SACK permitted was not advertised or a SYN, break */
197 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
200 /* If too short or not correctly formatted, break */
201 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
204 to->flags |= TCP_OPTS_FLAG_SACK;
205 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
206 vec_reset_length (to->sacks);
207 for (j = 0; j < to->n_sack_blocks; j++)
209 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 4 * j));
210 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 4 * j));
211 vec_add1 (to->sacks, b);
215 /* Nothing to see here */
223 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
224 * timestamp to echo and it's less than tsval_recent, drop segment
225 * but still send an ACK in order to retain TCP's mechanism for detecting
226 * and recovering from half-open connections
228 * Or at least that's what the theory says. It seems that this might not work
229 * very well with packet reordering and fast retransmit. XXX
232 tcp_segment_check_paws (tcp_connection_t * tc)
234 return tcp_opts_tstamp (&tc->opt) && tc->tsval_recent
235 && timestamp_lt (tc->opt.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->opt) && tc->tsval_recent
252 && seq_leq (seq, tc->rcv_las) && seq_leq (tc->rcv_las, seq_end))
254 tc->tsval_recent = tc->opt.tsval;
255 tc->tsval_recent_age = tcp_time_now ();
260 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
262 * It first verifies if segment has a wrapped sequence number (PAWS) and then
263 * does the processing associated to the first four steps (ignoring security
264 * and precedence): sequence number, rst bit and syn bit checks.
266 * @return 0 if segments passes validation.
269 tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0,
270 vlib_buffer_t * b0, tcp_header_t * th0, u32 * next0)
272 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
275 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->opt)))
280 if (tcp_segment_check_paws (tc0))
282 clib_warning ("paws failed");
283 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
284 vnet_buffer (b0)->tcp.seq_end);
286 /* If it just so happens that a segment updates tsval_recent for a
287 * segment over 24 days old, invalidate tsval_recent. */
288 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
291 /* Age isn't reset until we get a valid tsval (bsd inspired) */
292 tc0->tsval_recent = 0;
293 clib_warning ("paws failed - really old segment. REALLY?");
297 /* Drop after ack if not rst */
300 tcp_make_ack (tc0, b0);
301 *next0 = tcp_next_output (tc0->c_is_ip4);
302 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
308 /* 1st: check sequence number */
309 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
310 vnet_buffer (b0)->tcp.seq_end))
312 /* If our window is 0 and the packet is in sequence, let it pass
313 * through for ack processing. It should be dropped later.*/
314 if (tc0->rcv_wnd == 0
315 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
317 /* TODO Should segment be tagged? */
321 /* If not RST, send dup ack */
324 tcp_make_ack (tc0, b0);
325 *next0 = tcp_next_output (tc0->c_is_ip4);
326 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
332 /* 2nd: check the RST bit */
335 tcp_connection_reset (tc0);
339 /* 3rd: check security and precedence (skip) */
341 /* 4th: check the SYN bit */
344 tcp_send_reset (b0, tc0->c_is_ip4);
348 /* If segment in window, save timestamp */
349 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
350 vnet_buffer (b0)->tcp.seq_end);
356 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
358 /* SND.UNA =< SEG.ACK =< SND.NXT */
359 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
360 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
364 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
366 * Note that although the original article, srtt and rttvar are scaled
367 * to minimize round-off errors, here we don't. Instead, we rely on
368 * better precision time measurements.
370 * TODO support us rtt resolution
373 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
379 err = mrtt - tc->srtt;
380 tc->srtt += err >> 3;
382 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
383 * The increase should be bound */
384 tc->rttvar += ((int) clib_abs (err) - (int) tc->rttvar) >> 2;
388 /* First measurement. */
390 tc->rttvar = mrtt >> 1;
394 /** Update RTT estimate and RTO timer
396 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
397 * timing. Middle boxes are known to fiddle with TCP options so we
398 * should give higher priority to ACK timing.
400 * return 1 if valid rtt 0 otherwise
403 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
408 /* Determine if only rtx bytes are acked. TODO fast retransmit */
409 rtx_acked = tc->rto_boff && (tc->bytes_acked <= tc->snd_mss);
411 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
412 * RTT because they're ambiguous. */
413 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq) && !rtx_acked)
415 mrtt = tcp_time_now () - tc->rtt_ts;
417 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
418 * snd_una, i.e., the left side of the send window:
419 * seq_lt (tc->snd_una, ack). Note: last condition could be dropped, we don't
420 * try to update rtt for dupacks */
421 else if (tcp_opts_tstamp (&tc->opt) && tc->opt.tsecr && tc->bytes_acked)
423 mrtt = tcp_time_now () - tc->opt.tsecr;
426 /* Allow measuring of a new RTT */
429 /* If ACK moves left side of the wnd make sure boff is 0, even if mrtt is
434 /* Ignore dubious measurements */
435 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
438 tcp_estimate_rtt (tc, mrtt);
439 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
445 * Dequeue bytes that have been acked and while at it update RTT estimates.
448 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
450 /* Dequeue the newly ACKed bytes */
451 stream_session_dequeue_drop (&tc->connection, tc->bytes_acked);
453 /* Update rtt and rto */
454 tcp_update_rtt (tc, ack);
458 * Check if dupack as per RFC5681 Sec. 2
460 * This works only if called before updating snd_wnd.
463 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 new_snd_wnd)
465 return ((vnet_buffer (b)->tcp.ack_number == tc->snd_una)
466 && seq_gt (tc->snd_una_max, tc->snd_una)
467 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
468 && (new_snd_wnd == tc->snd_wnd));
472 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
474 sack_scoreboard_hole_t *next, *prev;
476 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
478 next = pool_elt_at_index (sb->holes, hole->next);
479 next->prev = hole->prev;
482 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
484 prev = pool_elt_at_index (sb->holes, hole->prev);
485 prev->next = hole->next;
489 sb->head = hole->next;
492 pool_put (sb->holes, hole);
495 sack_scoreboard_hole_t *
496 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
499 sack_scoreboard_hole_t *hole, *next, *prev;
502 pool_get (sb->holes, hole);
503 memset (hole, 0, sizeof (*hole));
507 hole_index = hole - sb->holes;
509 prev = scoreboard_get_hole (sb, prev_index);
512 hole->prev = prev - sb->holes;
513 hole->next = prev->next;
515 if ((next = scoreboard_next_hole (sb, hole)))
516 next->prev = hole_index;
518 prev->next = hole_index;
522 sb->head = hole_index;
523 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
524 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
531 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
533 sack_scoreboard_t *sb = &tc->sack_sb;
534 sack_block_t *blk, tmp;
535 sack_scoreboard_hole_t *hole, *next_hole, *last_hole, *new_hole;
536 u32 blk_index = 0, old_sacked_bytes, hole_index;
539 sb->last_sacked_bytes = 0;
541 old_sacked_bytes = sb->sacked_bytes;
543 if (!tcp_opts_sack (&tc->opt) && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
546 /* Remove invalid blocks */
548 while (blk < vec_end (tc->opt.sacks))
550 if (seq_lt (blk->start, blk->end)
551 && seq_gt (blk->start, tc->snd_una)
552 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_nxt))
557 vec_del1 (tc->opt.sacks, blk - tc->opt.sacks);
560 /* Add block for cumulative ack */
561 if (seq_gt (ack, tc->snd_una))
563 tmp.start = tc->snd_una;
565 vec_add1 (tc->opt.sacks, tmp);
568 if (vec_len (tc->opt.sacks) == 0)
571 /* Make sure blocks are ordered */
572 for (i = 0; i < vec_len (tc->opt.sacks); i++)
573 for (j = i + 1; j < vec_len (tc->opt.sacks); j++)
574 if (seq_lt (tc->opt.sacks[j].start, tc->opt.sacks[i].start))
576 tmp = tc->opt.sacks[i];
577 tc->opt.sacks[i] = tc->opt.sacks[j];
578 tc->opt.sacks[j] = tmp;
581 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
583 /* If no holes, insert the first that covers all outstanding bytes */
584 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
585 tc->snd_una, tc->snd_una_max);
586 sb->tail = scoreboard_hole_index (sb, last_hole);
590 /* If we have holes but snd_una_max is beyond the last hole, update
592 tmp = tc->opt.sacks[vec_len (tc->opt.sacks) - 1];
593 last_hole = scoreboard_last_hole (sb);
594 if (seq_gt (tc->snd_una_max, sb->max_byte_sacked)
595 && seq_gt (tc->snd_una_max, last_hole->end))
596 last_hole->end = tc->snd_una_max;
599 /* Walk the holes with the SACK blocks */
600 hole = pool_elt_at_index (sb->holes, sb->head);
601 while (hole && blk_index < vec_len (tc->opt.sacks))
603 blk = &tc->opt.sacks[blk_index];
605 if (seq_leq (blk->start, hole->start))
607 /* Block covers hole. Remove hole */
608 if (seq_geq (blk->end, hole->end))
610 next_hole = scoreboard_next_hole (sb, hole);
612 /* Byte accounting */
613 if (seq_leq (hole->end, ack))
615 /* Bytes lost because snd_wnd left edge advances */
616 if (next_hole && seq_leq (next_hole->start, ack))
617 sb->sacked_bytes -= next_hole->start - hole->end;
619 sb->sacked_bytes -= ack - hole->end;
623 sb->sacked_bytes += scoreboard_hole_bytes (hole);
626 /* snd_una needs to be advanced */
627 if (seq_geq (ack, hole->end))
629 if (next_hole && seq_lt (ack, next_hole->start))
630 sb->snd_una_adv = next_hole->start - ack;
632 sb->snd_una_adv = sb->max_byte_sacked - ack;
634 /* all these can be delivered */
635 sb->sacked_bytes -= sb->snd_una_adv;
638 /* About to remove last hole */
639 if (hole == last_hole)
641 sb->tail = hole->prev;
642 last_hole = scoreboard_last_hole (sb);
643 /* keep track of max byte sacked in case the last hole
645 if (seq_gt (hole->end, sb->max_byte_sacked))
646 sb->max_byte_sacked = hole->end;
648 scoreboard_remove_hole (sb, hole);
651 /* Partial 'head' overlap */
654 if (seq_gt (blk->end, hole->start))
656 sb->sacked_bytes += blk->end - hole->start;
657 hole->start = blk->end;
664 /* Hole must be split */
665 if (seq_lt (blk->end, hole->end))
667 sb->sacked_bytes += blk->end - blk->start;
668 hole_index = scoreboard_hole_index (sb, hole);
669 new_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
672 /* Pool might've moved */
673 hole = scoreboard_get_hole (sb, hole_index);
674 hole->end = blk->start;
676 /* New or split of tail */
677 if ((last_hole->end == new_hole->end)
678 || seq_lt (last_hole->end, new_hole->start))
680 last_hole = new_hole;
681 sb->tail = scoreboard_hole_index (sb, new_hole);
685 hole = scoreboard_next_hole (sb, hole);
689 sb->sacked_bytes += hole->end - blk->start;
690 hole->end = blk->start;
691 hole = scoreboard_next_hole (sb, hole);
696 sb->last_sacked_bytes = sb->sacked_bytes + sb->snd_una_adv
702 * If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
703 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
705 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
707 if (seq_lt (tc->snd_wl1, seq)
708 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
710 tc->snd_wnd = snd_wnd;
713 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
715 /* Set probe timer if we just got 0 wnd */
716 if (tc->snd_wnd < tc->snd_mss
717 && !tcp_timer_is_active (tc, TCP_TIMER_PERSIST))
718 tcp_persist_timer_set (tc);
720 tcp_persist_timer_reset (tc);
725 tcp_cc_congestion (tcp_connection_t * tc)
727 tc->snd_congestion = tc->snd_nxt;
728 tc->cc_algo->congestion (tc);
729 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
733 tcp_cc_recover (tcp_connection_t * tc)
735 /* TODO: check if time to recover was small. It might be that RTO popped
739 tc->cc_algo->recovered (tc);
743 tc->snd_nxt = tc->snd_una;
745 tc->cc_algo->rcv_ack (tc);
746 tc->tsecr_last_ack = tc->opt.tsecr;
748 tcp_cong_recovery_off (tc);
750 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
754 tcp_cc_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b)
758 if (tcp_in_fastrecovery (tc))
760 partial_ack = seq_lt (tc->snd_una, tc->snd_congestion);
763 /* Clear retransmitted bytes. */
768 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
770 /* Clear retransmitted bytes. XXX should we clear all? */
773 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
775 /* In case snd_nxt is still in the past and output tries to
776 * shove some new bytes */
777 tc->snd_nxt = tc->snd_una_max;
779 /* XXX need proper RFC6675 support */
780 if (tc->sack_sb.last_sacked_bytes && !tcp_in_recovery (tc))
782 tcp_fast_retransmit (tc);
786 /* Retransmit first unacked segment */
787 tcp_retransmit_first_unacked (tc);
793 tc->cc_algo->rcv_ack (tc);
794 tc->tsecr_last_ack = tc->opt.tsecr;
796 if (tcp_in_recovery (tc))
798 tc->rtx_bytes -= clib_min (tc->bytes_acked, tc->rtx_bytes);
799 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
800 if (seq_geq (tc->snd_una, tc->snd_congestion))
801 tcp_recovery_off (tc);
807 tcp_cc_rcv_dupack (tcp_connection_t * tc, u32 ack)
809 // ASSERT (seq_geq(tc->snd_una, ack));
812 if (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
814 /* RFC6582 NewReno heuristic to avoid multiple fast retransmits */
815 if (tc->opt.tsecr != tc->tsecr_last_ack)
821 tcp_fastrecovery_on (tc);
823 /* Handle congestion and dupack */
824 tcp_cc_congestion (tc);
825 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
827 tcp_fast_retransmit (tc);
829 /* Post retransmit update cwnd to ssthresh and account for the
830 * three segments that have left the network and should've been
831 * buffered at the receiver */
832 tc->cwnd = tc->ssthresh + TCP_DUPACK_THRESHOLD * tc->snd_mss;
834 else if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD)
836 ASSERT (tcp_in_fastrecovery (tc));
838 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
843 tcp_cc_init (tcp_connection_t * tc)
845 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
846 tc->cc_algo->init (tc);
850 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
851 tcp_header_t * th, u32 * next, u32 * error)
855 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
856 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt))
858 /* If we have outstanding data and this is within the window, accept it,
859 * probably retransmit has timed out. Otherwise ACK segment and then
861 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
863 tcp_make_ack (tc, b);
864 *next = tcp_next_output (tc->c_is_ip4);
865 *error = TCP_ERROR_ACK_INVALID;
866 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
867 vnet_buffer (b)->tcp.ack_number);
871 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
872 vnet_buffer (b)->tcp.ack_number);
874 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
875 *error = TCP_ERROR_ACK_FUTURE;
878 /* If old ACK, probably it's an old dupack */
879 if (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
881 *error = TCP_ERROR_ACK_OLD;
882 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
883 vnet_buffer (b)->tcp.ack_number);
884 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
886 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
887 tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number);
893 if (tcp_opts_sack_permitted (&tc->opt))
894 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
896 new_snd_wnd = clib_net_to_host_u16 (th->window) << tc->snd_wscale;
898 if (tcp_ack_is_dupack (tc, b, new_snd_wnd))
900 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
901 tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number);
902 *error = TCP_ERROR_ACK_DUP;
910 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
911 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
913 /* Dequeue ACKed data and update RTT */
914 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
915 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
916 vnet_buffer (b)->tcp.ack_number, new_snd_wnd);
918 /* If some of our sent bytes have been acked, update cc and retransmit
922 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
924 /* Updates congestion control (slow start/congestion avoidance) */
925 tcp_cc_rcv_ack (tc, b);
927 /* If everything has been acked, stop retransmit timer
928 * otherwise update. */
929 if (tc->snd_una == tc->snd_una_max)
930 tcp_retransmit_timer_reset (tc);
932 tcp_retransmit_timer_update (tc);
939 * Build SACK list as per RFC2018.
941 * Makes sure the first block contains the segment that generated the current
942 * ACK and the following ones are the ones most recently reported in SACK
945 * @param tc TCP connection for which the SACK list is updated
946 * @param start Start sequence number of the newest SACK block
947 * @param end End sequence of the newest SACK block
950 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
952 sack_block_t *new_list = 0, *block = 0;
955 /* If the first segment is ooo add it to the list. Last write might've moved
956 * rcv_nxt over the first segment. */
957 if (seq_lt (tc->rcv_nxt, start))
959 vec_add2 (new_list, block, 1);
960 block->start = start;
964 /* Find the blocks still worth keeping. */
965 for (i = 0; i < vec_len (tc->snd_sacks); i++)
967 /* Discard if rcv_nxt advanced beyond current block */
968 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
971 /* Merge or drop if segment overlapped by the new segment */
972 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
973 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
975 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
976 new_list[0].start = tc->snd_sacks[i].start;
977 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
978 new_list[0].end = tc->snd_sacks[i].end;
982 /* Save to new SACK list if we have space. */
983 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
985 vec_add1 (new_list, tc->snd_sacks[i]);
989 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
991 /* Replace old vector with new one */
992 vec_free (tc->snd_sacks);
993 tc->snd_sacks = new_list;
996 /** Enqueue data for delivery to application */
998 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1003 /* Pure ACK. Update rcv_nxt and be done. */
1004 if (PREDICT_FALSE (data_len == 0))
1006 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
1007 return TCP_ERROR_PURE_ACK;
1010 written = stream_session_enqueue_data (&tc->connection, b, 0,
1011 1 /* queue event */ , 1);
1013 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1015 /* Update rcv_nxt */
1016 if (PREDICT_TRUE (written == data_len))
1018 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
1020 /* If more data written than expected, account for out-of-order bytes. */
1021 else if (written > data_len)
1023 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end + written - data_len;
1025 /* Send ACK confirming the update */
1026 tc->flags |= TCP_CONN_SNDACK;
1028 else if (written > 0)
1030 /* We've written something but FIFO is probably full now */
1031 tc->rcv_nxt += written;
1033 /* Depending on how fast the app is, all remaining buffers in burst will
1034 * not be enqueued. Inform peer */
1035 tc->flags |= TCP_CONN_SNDACK;
1037 return TCP_ERROR_PARTIALLY_ENQUEUED;
1041 tc->flags |= TCP_CONN_SNDACK;
1042 return TCP_ERROR_FIFO_FULL;
1045 /* Update SACK list if need be */
1046 if (tcp_opts_sack_permitted (&tc->opt))
1048 /* Remove SACK blocks that have been delivered */
1049 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1052 return TCP_ERROR_ENQUEUED;
1055 /** Enqueue out-of-order data */
1057 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1060 stream_session_t *s0;
1063 /* Pure ACK. Do nothing */
1064 if (PREDICT_FALSE (data_len == 0))
1066 return TCP_ERROR_PURE_ACK;
1069 /* Enqueue out-of-order data with absolute offset */
1070 rv = stream_session_enqueue_data (&tc->connection, b,
1071 vnet_buffer (b)->tcp.seq_number,
1072 0 /* queue event */ , 0);
1074 /* Nothing written */
1077 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1078 return TCP_ERROR_FIFO_FULL;
1081 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1083 /* Update SACK list if in use */
1084 if (tcp_opts_sack_permitted (&tc->opt))
1086 ooo_segment_t *newest;
1089 s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
1091 /* Get the newest segment from the fifo */
1092 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1093 start = ooo_segment_offset (s0->server_rx_fifo, newest);
1094 end = ooo_segment_end_offset (s0->server_rx_fifo, newest);
1096 tcp_update_sack_list (tc, start, end);
1099 return TCP_ERROR_ENQUEUED;
1103 * Check if ACK could be delayed. If ack can be delayed, it should return
1104 * true for a full frame. If we're always acking return 0.
1107 tcp_can_delack (tcp_connection_t * tc)
1109 /* Send ack if ... */
1111 /* just sent a rcv wnd 0 */
1112 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1113 /* constrained to send ack */
1114 || (tc->flags & TCP_CONN_SNDACK) != 0
1115 /* we're almost out of tx wnd */
1116 || tcp_available_snd_space (tc) < 2 * tc->snd_mss)
1123 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1124 u16 n_data_bytes, u32 * next0)
1126 u32 error = 0, n_bytes_to_drop;
1128 /* Handle out-of-order data */
1129 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1131 /* Old sequence numbers allowed through because they overlapped
1133 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1135 error = TCP_ERROR_SEGMENT_OLD;
1136 *next0 = TCP_NEXT_DROP;
1138 /* Chop off the bytes in the past */
1139 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1140 n_data_bytes -= n_bytes_to_drop;
1141 vlib_buffer_advance (b, n_bytes_to_drop);
1146 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1148 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1149 * cwnd on remote peer when congested 2) acks leaving should have the
1150 * latest rcv_wnd since the burst may eaten up all of it, so only the
1151 * old ones could be filtered.
1154 /* RFC2581: Send DUPACK for fast retransmit */
1155 tcp_make_ack (tc, b);
1156 *next0 = tcp_next_output (tc->c_is_ip4);
1158 /* Mark as DUPACK. We may filter these in output if
1159 * the burst fills the holes. */
1161 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1163 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1169 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1170 * segments can be enqueued after fifo tail offset changes. */
1171 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1173 if (n_data_bytes == 0)
1175 *next0 = TCP_NEXT_DROP;
1179 /* Check if ACK can be delayed */
1180 if (tcp_can_delack (tc))
1182 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1183 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1187 *next0 = tcp_next_output (tc->c_is_ip4);
1188 tcp_make_ack (tc, b);
1196 tcp_header_t tcp_header;
1197 tcp_connection_t tcp_connection;
1201 format_tcp_rx_trace (u8 * s, va_list * args)
1203 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1204 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1205 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1206 uword indent = format_get_indent (s);
1208 s = format (s, "%U\n%U%U",
1209 format_tcp_header, &t->tcp_header, 128,
1210 format_white_space, indent,
1211 format_tcp_connection_verbose, &t->tcp_connection);
1217 format_tcp_rx_trace_short (u8 * s, va_list * args)
1219 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1220 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1221 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1223 s = format (s, "%d -> %d (%U)",
1224 clib_net_to_host_u16 (t->tcp_header.src_port),
1225 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1226 &t->tcp_connection.state);
1232 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1233 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1237 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1241 th0 = tcp_buffer_hdr (b0);
1243 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1247 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1249 if (PREDICT_TRUE (!val))
1253 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1255 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1259 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1260 vlib_frame_t * from_frame, int is_ip4)
1262 u32 n_left_from, next_index, *from, *to_next;
1263 u32 my_thread_index = vm->thread_index, errors = 0;
1264 tcp_main_t *tm = vnet_get_tcp_main ();
1267 from = vlib_frame_vector_args (from_frame);
1268 n_left_from = from_frame->n_vectors;
1270 next_index = node->cached_next_index;
1272 while (n_left_from > 0)
1276 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1278 while (n_left_from > 0 && n_left_to_next > 0)
1282 tcp_header_t *th0 = 0;
1283 tcp_connection_t *tc0;
1284 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1291 n_left_to_next -= 1;
1293 b0 = vlib_get_buffer (vm, bi0);
1294 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1297 if (PREDICT_FALSE (tc0 == 0))
1299 error0 = TCP_ERROR_INVALID_CONNECTION;
1303 th0 = tcp_buffer_hdr (b0);
1305 is_fin = (th0->flags & TCP_FLAG_FIN) != 0;
1307 /* SYNs, FINs and data consume sequence numbers */
1308 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1309 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1311 /* TODO header prediction fast path */
1313 /* 1-4: check SEQ, RST, SYN */
1314 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1316 error0 = TCP_ERROR_SEGMENT_INVALID;
1317 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1318 vnet_buffer (b0)->tcp.seq_number,
1319 vnet_buffer (b0)->tcp.seq_end);
1323 /* 5: check the ACK field */
1324 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1329 /* 6: check the URG bit TODO */
1331 /* 7: process the segment text */
1333 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1334 error0 = tcp_segment_rcv (tm, tc0, b0,
1335 vnet_buffer (b0)->tcp.data_len, &next0);
1337 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1338 * dangling reference. */
1340 /* 8: check the FIN bit */
1343 /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
1344 * wait for session to call close. To avoid lingering
1345 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1346 tc0->state = TCP_STATE_CLOSE_WAIT;
1347 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1348 stream_session_disconnect_notify (&tc0->connection);
1349 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1353 b0->error = node->errors[error0];
1354 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1356 tcp_rx_trace_t *t0 =
1357 vlib_add_trace (vm, node, b0, sizeof (*t0));
1358 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1361 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1362 n_left_to_next, bi0, next0);
1365 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1368 errors = session_manager_flush_enqueue_events (my_thread_index);
1369 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1371 return from_frame->n_vectors;
1375 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1376 vlib_frame_t * from_frame)
1378 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1382 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1383 vlib_frame_t * from_frame)
1385 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1389 VLIB_REGISTER_NODE (tcp4_established_node) =
1391 .function = tcp4_established,
1392 .name = "tcp4-established",
1393 /* Takes a vector of packets. */
1394 .vector_size = sizeof (u32),
1395 .n_errors = TCP_N_ERROR,
1396 .error_strings = tcp_error_strings,
1397 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1400 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1401 foreach_tcp_state_next
1404 .format_trace = format_tcp_rx_trace_short,
1408 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1411 VLIB_REGISTER_NODE (tcp6_established_node) =
1413 .function = tcp6_established,
1414 .name = "tcp6-established",
1415 /* Takes a vector of packets. */
1416 .vector_size = sizeof (u32),
1417 .n_errors = TCP_N_ERROR,
1418 .error_strings = tcp_error_strings,
1419 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1422 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1423 foreach_tcp_state_next
1426 .format_trace = format_tcp_rx_trace_short,
1431 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1433 vlib_node_registration_t tcp4_syn_sent_node;
1434 vlib_node_registration_t tcp6_syn_sent_node;
1437 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1438 vlib_frame_t * from_frame, int is_ip4)
1440 tcp_main_t *tm = vnet_get_tcp_main ();
1441 u32 n_left_from, next_index, *from, *to_next;
1442 u32 my_thread_index = vm->thread_index, errors = 0;
1443 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
1445 from = vlib_frame_vector_args (from_frame);
1446 n_left_from = from_frame->n_vectors;
1448 next_index = node->cached_next_index;
1450 while (n_left_from > 0)
1454 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1456 while (n_left_from > 0 && n_left_to_next > 0)
1458 u32 bi0, ack0, seq0;
1461 tcp_header_t *tcp0 = 0;
1462 tcp_connection_t *tc0;
1463 tcp_connection_t *new_tc0;
1464 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1471 n_left_to_next -= 1;
1473 b0 = vlib_get_buffer (vm, bi0);
1475 tcp_half_open_connection_get (vnet_buffer (b0)->
1476 tcp.connection_index);
1478 ack0 = vnet_buffer (b0)->tcp.ack_number;
1479 seq0 = vnet_buffer (b0)->tcp.seq_number;
1480 tcp0 = tcp_buffer_hdr (b0);
1483 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1486 /* SYNs, FINs and data consume sequence numbers */
1487 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1488 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
1491 * 1. check the ACK bit
1495 * If the ACK bit is set
1496 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
1497 * the RST bit is set, if so drop the segment and return)
1498 * <SEQ=SEG.ACK><CTL=RST>
1499 * and discard the segment. Return.
1500 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
1504 if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt)
1506 if (!tcp_rst (tcp0))
1507 tcp_send_reset (b0, is_ip4);
1512 /* Make sure ACK is valid */
1513 if (tc0->snd_una > ack0)
1518 * 2. check the RST bit
1523 /* If ACK is acceptable, signal client that peer is not
1524 * willing to accept connection and drop connection*/
1527 stream_session_connect_notify (&tc0->connection, sst,
1529 tcp_connection_cleanup (tc0);
1535 * 3. check the security and precedence (skipped)
1539 * 4. check the SYN bit
1542 /* No SYN flag. Drop. */
1543 if (!tcp_syn (tcp0))
1546 /* Stop connection establishment and retransmit timers */
1547 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
1548 tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT_SYN);
1550 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
1551 * current thread pool. */
1552 pool_get (tm->connections[my_thread_index], new_tc0);
1553 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
1555 new_tc0->c_thread_index = my_thread_index;
1557 /* Cleanup half-open connection XXX lock */
1558 pool_put (tm->half_open_connections, tc0);
1560 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
1561 new_tc0->irs = seq0;
1564 if (tcp_options_parse (tcp0, &new_tc0->opt))
1567 if (tcp_opts_tstamp (&new_tc0->opt))
1569 new_tc0->tsval_recent = new_tc0->opt.tsval;
1570 new_tc0->tsval_recent_age = tcp_time_now ();
1573 if (tcp_opts_wscale (&new_tc0->opt))
1574 new_tc0->snd_wscale = new_tc0->opt.wscale;
1577 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
1578 new_tc0->snd_wl1 = seq0;
1579 new_tc0->snd_wl2 = ack0;
1581 tcp_connection_init_vars (new_tc0);
1583 /* SYN-ACK: See if we can switch to ESTABLISHED state */
1586 /* Our SYN is ACKed: we have iss < ack = snd_una */
1588 /* TODO Dequeue acknowledged segments if we support Fast Open */
1589 new_tc0->snd_una = ack0;
1590 new_tc0->state = TCP_STATE_ESTABLISHED;
1592 /* Make sure las is initialized for the wnd computation */
1593 new_tc0->rcv_las = new_tc0->rcv_nxt;
1595 /* Notify app that we have connection */
1596 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1598 stream_session_init_fifos_pointers (&new_tc0->connection,
1601 /* Make sure after data segment processing ACK is sent */
1602 new_tc0->flags |= TCP_CONN_SNDACK;
1604 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
1607 new_tc0->state = TCP_STATE_SYN_RCVD;
1609 /* Notify app that we have connection */
1610 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1611 stream_session_init_fifos_pointers (&new_tc0->connection,
1614 tcp_make_synack (new_tc0, b0);
1615 next0 = tcp_next_output (is_ip4);
1620 /* Read data, if any */
1621 if (vnet_buffer (b0)->tcp.data_len)
1623 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1624 error0 = tcp_segment_rcv (tm, new_tc0, b0,
1625 vnet_buffer (b0)->tcp.data_len,
1627 if (error0 == TCP_ERROR_PURE_ACK)
1628 error0 = TCP_ERROR_SYN_ACKS_RCVD;
1632 tcp_make_ack (new_tc0, b0);
1633 next0 = tcp_next_output (new_tc0->c_is_ip4);
1638 b0->error = error0 ? node->errors[error0] : 0;
1639 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1641 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1642 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
1643 clib_memcpy (&t0->tcp_connection, tc0,
1644 sizeof (t0->tcp_connection));
1647 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1648 n_left_to_next, bi0, next0);
1651 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1654 errors = session_manager_flush_enqueue_events (my_thread_index);
1658 vlib_node_increment_counter (vm, tcp4_established_node.index,
1659 TCP_ERROR_EVENT_FIFO_FULL, errors);
1661 vlib_node_increment_counter (vm, tcp6_established_node.index,
1662 TCP_ERROR_EVENT_FIFO_FULL, errors);
1665 return from_frame->n_vectors;
1669 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
1670 vlib_frame_t * from_frame)
1672 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1676 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
1677 vlib_frame_t * from_frame)
1679 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1683 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
1685 .function = tcp4_syn_sent,
1686 .name = "tcp4-syn-sent",
1687 /* Takes a vector of packets. */
1688 .vector_size = sizeof (u32),
1689 .n_errors = TCP_N_ERROR,
1690 .error_strings = tcp_error_strings,
1691 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1694 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1695 foreach_tcp_state_next
1698 .format_trace = format_tcp_rx_trace_short,
1702 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
1705 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
1707 .function = tcp6_syn_sent_rcv,
1708 .name = "tcp6-syn-sent",
1709 /* Takes a vector of packets. */
1710 .vector_size = sizeof (u32),
1711 .n_errors = TCP_N_ERROR,
1712 .error_strings = tcp_error_strings,
1713 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1716 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1717 foreach_tcp_state_next
1720 .format_trace = format_tcp_rx_trace_short,
1724 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
1726 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
1727 * as per RFC793 p. 64
1730 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1731 vlib_frame_t * from_frame, int is_ip4)
1733 tcp_main_t *tm = vnet_get_tcp_main ();
1734 u32 n_left_from, next_index, *from, *to_next;
1735 u32 my_thread_index = vm->thread_index, errors = 0;
1737 from = vlib_frame_vector_args (from_frame);
1738 n_left_from = from_frame->n_vectors;
1740 next_index = node->cached_next_index;
1742 while (n_left_from > 0)
1746 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1748 while (n_left_from > 0 && n_left_to_next > 0)
1752 tcp_header_t *tcp0 = 0;
1753 tcp_connection_t *tc0;
1754 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1761 n_left_to_next -= 1;
1763 b0 = vlib_get_buffer (vm, bi0);
1764 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1766 if (PREDICT_FALSE (tc0 == 0))
1768 error0 = TCP_ERROR_INVALID_CONNECTION;
1772 tcp0 = tcp_buffer_hdr (b0);
1774 /* SYNs, FINs and data consume sequence numbers */
1775 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1776 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0)
1777 + vnet_buffer (b0)->tcp.data_len;
1780 * Special treatment for CLOSED
1784 case TCP_STATE_CLOSED:
1790 * For all other states (except LISTEN)
1793 /* 1-4: check SEQ, RST, SYN */
1795 (tcp_segment_validate (vm, tc0, b0, tcp0, &next0)))
1797 error0 = TCP_ERROR_SEGMENT_INVALID;
1801 /* 5: check the ACK field */
1804 case TCP_STATE_SYN_RCVD:
1806 * If the segment acknowledgment is not acceptable, form a
1808 * <SEQ=SEG.ACK><CTL=RST>
1811 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
1813 tcp_send_reset (b0, is_ip4);
1817 /* Update rtt and rto */
1818 tc0->bytes_acked = 1;
1819 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
1821 /* Switch state to ESTABLISHED */
1822 tc0->state = TCP_STATE_ESTABLISHED;
1824 /* Initialize session variables */
1825 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
1826 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
1828 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
1829 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
1831 /* Shoulder tap the server */
1832 stream_session_accept_notify (&tc0->connection);
1834 /* Reset SYN-ACK retransmit timer */
1835 tcp_retransmit_timer_reset (tc0);
1837 case TCP_STATE_ESTABLISHED:
1838 /* We can get packets in established state here because they
1839 * were enqueued before state change */
1840 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1844 case TCP_STATE_FIN_WAIT_1:
1845 /* In addition to the processing for the ESTABLISHED state, if
1846 * our FIN is now acknowledged then enter FIN-WAIT-2 and
1847 * continue processing in that state. */
1848 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1851 /* If FIN is ACKed */
1852 if (tc0->snd_una == tc0->snd_una_max)
1854 tc0->state = TCP_STATE_FIN_WAIT_2;
1855 /* Stop all timers, 2MSL will be set lower */
1856 tcp_connection_timers_reset (tc0);
1859 case TCP_STATE_FIN_WAIT_2:
1860 /* In addition to the processing for the ESTABLISHED state, if
1861 * the retransmission queue is empty, the user's CLOSE can be
1862 * acknowledged ("ok") but do not delete the TCB. */
1863 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1865 /* check if rtx queue is empty and ack CLOSE TODO */
1867 case TCP_STATE_CLOSE_WAIT:
1868 /* Do the same processing as for the ESTABLISHED state. */
1869 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1872 case TCP_STATE_CLOSING:
1873 /* In addition to the processing for the ESTABLISHED state, if
1874 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
1875 * otherwise ignore the segment. */
1876 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1879 /* XXX test that send queue empty */
1880 tc0->state = TCP_STATE_TIME_WAIT;
1884 case TCP_STATE_LAST_ACK:
1885 /* The only thing that can arrive in this state is an
1886 * acknowledgment of our FIN. If our FIN is now acknowledged,
1887 * delete the TCB, enter the CLOSED state, and return. */
1889 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
1892 tc0->state = TCP_STATE_CLOSED;
1894 /* Don't delete the connection/session yet. Instead, wait a
1895 * reasonable amount of time until the pipes are cleared. In
1896 * particular, this makes sure that we won't have dead sessions
1897 * when processing events on the tx path */
1898 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
1900 /* Stop retransmit */
1901 tcp_retransmit_timer_reset (tc0);
1906 case TCP_STATE_TIME_WAIT:
1907 /* The only thing that can arrive in this state is a
1908 * retransmission of the remote FIN. Acknowledge it, and restart
1909 * the 2 MSL timeout. */
1918 /* 6: check the URG bit TODO */
1920 /* 7: process the segment text */
1923 case TCP_STATE_ESTABLISHED:
1924 case TCP_STATE_FIN_WAIT_1:
1925 case TCP_STATE_FIN_WAIT_2:
1926 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1927 error0 = tcp_segment_rcv (tm, tc0, b0,
1928 vnet_buffer (b0)->tcp.data_len,
1931 case TCP_STATE_CLOSE_WAIT:
1932 case TCP_STATE_CLOSING:
1933 case TCP_STATE_LAST_ACK:
1934 case TCP_STATE_TIME_WAIT:
1935 /* This should not occur, since a FIN has been received from the
1936 * remote side. Ignore the segment text. */
1940 /* 8: check the FIN bit */
1941 if (!tcp_fin (tcp0))
1946 case TCP_STATE_ESTABLISHED:
1947 case TCP_STATE_SYN_RCVD:
1948 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
1949 tcp_connection_timers_reset (tc0);
1950 tcp_make_fin (tc0, b0);
1951 next0 = tcp_next_output (tc0->c_is_ip4);
1952 stream_session_disconnect_notify (&tc0->connection);
1953 tc0->state = TCP_STATE_CLOSE_WAIT;
1955 case TCP_STATE_CLOSE_WAIT:
1956 case TCP_STATE_CLOSING:
1957 case TCP_STATE_LAST_ACK:
1960 case TCP_STATE_FIN_WAIT_1:
1961 tc0->state = TCP_STATE_TIME_WAIT;
1962 tcp_connection_timers_reset (tc0);
1963 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
1965 case TCP_STATE_FIN_WAIT_2:
1966 /* Got FIN, send ACK! */
1967 tc0->state = TCP_STATE_TIME_WAIT;
1968 tcp_connection_timers_reset (tc0);
1969 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1970 tcp_make_ack (tc0, b0);
1971 next0 = tcp_next_output (is_ip4);
1973 case TCP_STATE_TIME_WAIT:
1974 /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
1977 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
1980 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1983 b0->error = error0 ? node->errors[error0] : 0;
1985 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1987 tcp_rx_trace_t *t0 =
1988 vlib_add_trace (vm, node, b0, sizeof (*t0));
1989 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
1992 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1993 n_left_to_next, bi0, next0);
1996 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1999 errors = session_manager_flush_enqueue_events (my_thread_index);
2003 vlib_node_increment_counter (vm, tcp4_established_node.index,
2004 TCP_ERROR_EVENT_FIFO_FULL, errors);
2006 vlib_node_increment_counter (vm, tcp6_established_node.index,
2007 TCP_ERROR_EVENT_FIFO_FULL, errors);
2010 return from_frame->n_vectors;
2014 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2015 vlib_frame_t * from_frame)
2017 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2021 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2022 vlib_frame_t * from_frame)
2024 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2028 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2030 .function = tcp4_rcv_process,
2031 .name = "tcp4-rcv-process",
2032 /* Takes a vector of packets. */
2033 .vector_size = sizeof (u32),
2034 .n_errors = TCP_N_ERROR,
2035 .error_strings = tcp_error_strings,
2036 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2039 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2040 foreach_tcp_state_next
2043 .format_trace = format_tcp_rx_trace_short,
2047 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2050 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2052 .function = tcp6_rcv_process,
2053 .name = "tcp6-rcv-process",
2054 /* Takes a vector of packets. */
2055 .vector_size = sizeof (u32),
2056 .n_errors = TCP_N_ERROR,
2057 .error_strings = tcp_error_strings,
2058 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2061 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2062 foreach_tcp_state_next
2065 .format_trace = format_tcp_rx_trace_short,
2069 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2071 vlib_node_registration_t tcp4_listen_node;
2072 vlib_node_registration_t tcp6_listen_node;
2075 * LISTEN state processing as per RFC 793 p. 65
2078 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2079 vlib_frame_t * from_frame, int is_ip4)
2081 u32 n_left_from, next_index, *from, *to_next;
2082 u32 my_thread_index = vm->thread_index;
2083 tcp_main_t *tm = vnet_get_tcp_main ();
2084 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
2086 from = vlib_frame_vector_args (from_frame);
2087 n_left_from = from_frame->n_vectors;
2089 next_index = node->cached_next_index;
2091 while (n_left_from > 0)
2095 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2097 while (n_left_from > 0 && n_left_to_next > 0)
2102 tcp_header_t *th0 = 0;
2103 tcp_connection_t *lc0;
2106 tcp_connection_t *child0;
2107 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2114 n_left_to_next -= 1;
2116 b0 = vlib_get_buffer (vm, bi0);
2117 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2121 ip40 = vlib_buffer_get_current (b0);
2122 th0 = ip4_next_header (ip40);
2126 ip60 = vlib_buffer_get_current (b0);
2127 th0 = ip6_next_header (ip60);
2130 /* Create child session. For syn-flood protection use filter */
2132 /* 1. first check for an RST: handled in dispatch */
2133 /* if (tcp_rst (th0))
2136 /* 2. second check for an ACK: handled in dispatch */
2137 /* if (tcp_ack (th0))
2139 tcp_send_reset (b0, is_ip4);
2143 /* 3. check for a SYN (did that already) */
2145 /* Create child session and send SYN-ACK */
2146 pool_get (tm->connections[my_thread_index], child0);
2147 memset (child0, 0, sizeof (*child0));
2149 child0->c_c_index = child0 - tm->connections[my_thread_index];
2150 child0->c_lcl_port = lc0->c_lcl_port;
2151 child0->c_rmt_port = th0->src_port;
2152 child0->c_is_ip4 = is_ip4;
2153 child0->c_thread_index = my_thread_index;
2157 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2158 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2162 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2163 sizeof (ip6_address_t));
2164 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2165 sizeof (ip6_address_t));
2168 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2171 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2175 if (tcp_options_parse (th0, &child0->opt))
2180 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2181 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2182 child0->rcv_las = child0->rcv_nxt;
2183 child0->state = TCP_STATE_SYN_RCVD;
2185 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2186 * segments are used to initialize PAWS. */
2187 if (tcp_opts_tstamp (&child0->opt))
2189 child0->tsval_recent = child0->opt.tsval;
2190 child0->tsval_recent_age = tcp_time_now ();
2193 if (tcp_opts_wscale (&child0->opt))
2194 child0->snd_wscale = child0->opt.wscale;
2197 child0->snd_wnd = clib_net_to_host_u16 (th0->window);
2198 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2199 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2201 tcp_connection_init_vars (child0);
2203 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0);
2205 /* Reuse buffer to make syn-ack and send */
2206 tcp_make_synack (child0, b0);
2207 next0 = tcp_next_output (is_ip4);
2209 /* Init fifo pointers after we have iss */
2210 stream_session_init_fifos_pointers (&child0->connection,
2214 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2216 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2217 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2218 clib_memcpy (&t0->tcp_connection, lc0,
2219 sizeof (t0->tcp_connection));
2222 b0->error = node->errors[error0];
2224 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2225 n_left_to_next, bi0, next0);
2228 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2230 return from_frame->n_vectors;
2234 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2235 vlib_frame_t * from_frame)
2237 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2241 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2242 vlib_frame_t * from_frame)
2244 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2248 VLIB_REGISTER_NODE (tcp4_listen_node) =
2250 .function = tcp4_listen,
2251 .name = "tcp4-listen",
2252 /* Takes a vector of packets. */
2253 .vector_size = sizeof (u32),
2254 .n_errors = TCP_N_ERROR,
2255 .error_strings = tcp_error_strings,
2256 .n_next_nodes = TCP_LISTEN_N_NEXT,
2259 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2260 foreach_tcp_state_next
2263 .format_trace = format_tcp_rx_trace_short,
2267 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2270 VLIB_REGISTER_NODE (tcp6_listen_node) =
2272 .function = tcp6_listen,
2273 .name = "tcp6-listen",
2274 /* Takes a vector of packets. */
2275 .vector_size = sizeof (u32),
2276 .n_errors = TCP_N_ERROR,
2277 .error_strings = tcp_error_strings,
2278 .n_next_nodes = TCP_LISTEN_N_NEXT,
2281 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2282 foreach_tcp_state_next
2285 .format_trace = format_tcp_rx_trace_short,
2289 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2291 vlib_node_registration_t tcp4_input_node;
2292 vlib_node_registration_t tcp6_input_node;
2294 typedef enum _tcp_input_next
2296 TCP_INPUT_NEXT_DROP,
2297 TCP_INPUT_NEXT_LISTEN,
2298 TCP_INPUT_NEXT_RCV_PROCESS,
2299 TCP_INPUT_NEXT_SYN_SENT,
2300 TCP_INPUT_NEXT_ESTABLISHED,
2301 TCP_INPUT_NEXT_RESET,
2305 #define foreach_tcp4_input_next \
2306 _ (DROP, "error-drop") \
2307 _ (LISTEN, "tcp4-listen") \
2308 _ (RCV_PROCESS, "tcp4-rcv-process") \
2309 _ (SYN_SENT, "tcp4-syn-sent") \
2310 _ (ESTABLISHED, "tcp4-established") \
2311 _ (RESET, "tcp4-reset")
2313 #define foreach_tcp6_input_next \
2314 _ (DROP, "error-drop") \
2315 _ (LISTEN, "tcp6-listen") \
2316 _ (RCV_PROCESS, "tcp6-rcv-process") \
2317 _ (SYN_SENT, "tcp6-syn-sent") \
2318 _ (ESTABLISHED, "tcp6-established") \
2319 _ (RESET, "tcp6-reset")
2321 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2324 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2325 vlib_frame_t * from_frame, int is_ip4)
2327 u32 n_left_from, next_index, *from, *to_next;
2328 u32 my_thread_index = vm->thread_index;
2329 tcp_main_t *tm = vnet_get_tcp_main ();
2331 from = vlib_frame_vector_args (from_frame);
2332 n_left_from = from_frame->n_vectors;
2334 next_index = node->cached_next_index;
2336 while (n_left_from > 0)
2340 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2342 while (n_left_from > 0 && n_left_to_next > 0)
2344 int n_advance_bytes0, n_data_bytes0;
2347 tcp_header_t *tcp0 = 0;
2348 tcp_connection_t *tc0;
2351 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2359 n_left_to_next -= 1;
2361 b0 = vlib_get_buffer (vm, bi0);
2362 vnet_buffer (b0)->tcp.flags = 0;
2364 /* Checksum computed by ipx_local no need to compute again */
2368 ip40 = vlib_buffer_get_current (b0);
2369 tcp0 = ip4_next_header (ip40);
2370 n_advance_bytes0 = (ip4_header_bytes (ip40)
2371 + tcp_header_bytes (tcp0));
2372 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2375 /* lookup session */
2377 (tcp_connection_t *)
2378 stream_session_lookup_transport4 (&ip40->dst_address,
2382 SESSION_TYPE_IP4_TCP,
2387 ip60 = vlib_buffer_get_current (b0);
2388 tcp0 = ip6_next_header (ip60);
2389 n_advance_bytes0 = tcp_header_bytes (tcp0);
2390 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2392 n_advance_bytes0 += sizeof (ip60[0]);
2395 (tcp_connection_t *)
2396 stream_session_lookup_transport6 (&ip60->src_address,
2400 SESSION_TYPE_IP6_TCP,
2405 if (PREDICT_FALSE (n_advance_bytes0 < 0))
2407 error0 = TCP_ERROR_LENGTH;
2411 /* Session exists */
2412 if (PREDICT_TRUE (0 != tc0))
2414 /* Save connection index */
2415 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2416 vnet_buffer (b0)->tcp.seq_number =
2417 clib_net_to_host_u32 (tcp0->seq_number);
2418 vnet_buffer (b0)->tcp.ack_number =
2419 clib_net_to_host_u32 (tcp0->ack_number);
2421 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
2422 - (u8 *) vlib_buffer_get_current (b0);
2423 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
2424 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
2426 flags0 = tcp0->flags & filter_flags;
2427 next0 = tm->dispatch_table[tc0->state][flags0].next;
2428 error0 = tm->dispatch_table[tc0->state][flags0].error;
2430 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH
2431 || next0 == TCP_INPUT_NEXT_RESET))
2433 /* Overload tcp flags to store state */
2434 tcp_state_t state0 = tc0->state;
2435 vnet_buffer (b0)->tcp.flags = tc0->state;
2437 if (error0 == TCP_ERROR_DISPATCH)
2438 clib_warning ("disp error state %U flags %U",
2439 format_tcp_state, &state0, format_tcp_flags,
2446 next0 = TCP_INPUT_NEXT_RESET;
2447 error0 = TCP_ERROR_NO_LISTENER;
2451 b0->error = error0 ? node->errors[error0] : 0;
2453 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2455 tcp_rx_trace_t *t0 =
2456 vlib_add_trace (vm, node, b0, sizeof (*t0));
2457 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2460 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2461 n_left_to_next, bi0, next0);
2464 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2467 return from_frame->n_vectors;
2471 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2472 vlib_frame_t * from_frame)
2474 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2478 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2479 vlib_frame_t * from_frame)
2481 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2485 VLIB_REGISTER_NODE (tcp4_input_node) =
2487 .function = tcp4_input,
2488 .name = "tcp4-input",
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_INPUT_N_NEXT,
2496 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2497 foreach_tcp4_input_next
2500 .format_buffer = format_tcp_header,
2501 .format_trace = format_tcp_rx_trace,
2505 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
2508 VLIB_REGISTER_NODE (tcp6_input_node) =
2510 .function = tcp6_input,
2511 .name = "tcp6-input",
2512 /* Takes a vector of packets. */
2513 .vector_size = sizeof (u32),
2514 .n_errors = TCP_N_ERROR,
2515 .error_strings = tcp_error_strings,
2516 .n_next_nodes = TCP_INPUT_N_NEXT,
2519 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2520 foreach_tcp6_input_next
2523 .format_buffer = format_tcp_header,
2524 .format_trace = format_tcp_rx_trace,
2528 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
2531 tcp_dispatch_table_init (tcp_main_t * tm)
2534 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
2535 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
2537 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
2538 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
2541 #define _(t,f,n,e) \
2543 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
2544 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
2547 /* SYNs for new connections -> tcp-listen. */
2548 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
2549 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
2550 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_NONE);
2551 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
2552 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2553 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2554 /* SYN-ACK for a SYN */
2555 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2557 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2558 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2559 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2561 /* ACK for for established connection -> tcp-established. */
2562 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2563 /* FIN for for established connection -> tcp-established. */
2564 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2565 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2567 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2568 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2570 /* ACK or FIN-ACK to our FIN */
2571 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2572 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
2574 /* FIN in reply to our FIN from the other side */
2575 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2576 /* FIN confirming that the peer (app) has closed */
2577 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2578 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2579 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2581 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2582 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2583 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_CONNECTION_CLOSED);
2584 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
2589 tcp_input_init (vlib_main_t * vm)
2591 clib_error_t *error = 0;
2592 tcp_main_t *tm = vnet_get_tcp_main ();
2594 if ((error = vlib_call_init_function (vm, tcp_init)))
2597 /* Initialize dispatch table. */
2598 tcp_dispatch_table_init (tm);
2603 VLIB_INIT_FUNCTION (tcp_input_init);
2606 * fd.io coding-style-patch-verification: ON
2609 * eval: (c-set-style "gnu")