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 tcp_options_parse (tcp_header_t * th, tcp_options_t * to)
119 u8 opt_len, opts_len, kind;
123 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
124 data = (const u8 *) (th + 1);
126 /* Zero out all flags but those set in SYN */
127 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE);
129 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
133 /* Get options length */
134 if (kind == TCP_OPTION_EOL)
136 else if (kind == TCP_OPTION_NOOP)
145 /* weird option length */
146 if (opt_len < 2 || opt_len > opts_len)
154 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
156 to->flags |= TCP_OPTS_FLAG_MSS;
157 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
160 case TCP_OPTION_WINDOW_SCALE:
161 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
163 to->flags |= TCP_OPTS_FLAG_WSCALE;
164 to->wscale = data[2];
165 if (to->wscale > TCP_MAX_WND_SCALE)
167 clib_warning ("Illegal window scaling value: %d",
169 to->wscale = TCP_MAX_WND_SCALE;
173 case TCP_OPTION_TIMESTAMP:
174 if (opt_len == TCP_OPTION_LEN_TIMESTAMP)
176 to->flags |= TCP_OPTS_FLAG_TSTAMP;
177 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
178 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
181 case TCP_OPTION_SACK_PERMITTED:
182 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
183 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
185 case TCP_OPTION_SACK_BLOCK:
186 /* If SACK permitted was not advertised or a SYN, break */
187 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
190 /* If too short or not correctly formatted, break */
191 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
194 to->flags |= TCP_OPTS_FLAG_SACK;
195 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
196 vec_reset_length (to->sacks);
197 for (j = 0; j < to->n_sack_blocks; j++)
199 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 4 * j));
200 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 4 * j));
201 vec_add1 (to->sacks, b);
205 /* Nothing to see here */
212 tcp_segment_check_paws (tcp_connection_t * tc)
214 /* XXX normally test for timestamp should be lt instead of leq, but for
215 * local testing this is not enough */
216 return tcp_opts_tstamp (&tc->opt) && tc->tsval_recent
217 && timestamp_lt (tc->opt.tsval, tc->tsval_recent);
221 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
223 * It first verifies if segment has a wrapped sequence number (PAWS) and then
224 * does the processing associated to the first four steps (ignoring security
225 * and precedence): sequence number, rst bit and syn bit checks.
227 * @return 0 if segments passes validation.
230 tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0,
231 vlib_buffer_t * b0, tcp_header_t * th0, u32 * next0)
235 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
238 tcp_options_parse (th0, &tc0->opt);
240 /* RFC1323: Check against wrapped sequence numbers (PAWS). If we have
241 * timestamp to echo and it's less than tsval_recent, drop segment
242 * but still send an ACK in order to retain TCP's mechanism for detecting
243 * and recovering from half-open connections */
244 paws_failed = tcp_segment_check_paws (tc0);
247 clib_warning ("paws failed");
249 /* If it just so happens that a segment updates tsval_recent for a
250 * segment over 24 days old, invalidate tsval_recent. */
251 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
254 /* Age isn't reset until we get a valid tsval (bsd inspired) */
255 tc0->tsval_recent = 0;
259 /* Drop after ack if not rst */
262 tcp_make_ack (tc0, b0);
263 *next0 = tcp_next_output (tc0->c_is_ip4);
264 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
270 /* 1st: check sequence number */
271 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
272 vnet_buffer (b0)->tcp.seq_end))
274 /* If our window is 0 and the packet is in sequence, let it pass
275 * through for ack processing. It should be dropped later.*/
276 if (tc0->rcv_wnd == 0
277 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
279 /* Make it look as if there's nothing to dequeue */
280 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number;
284 /* If not RST, send dup ack */
287 tcp_make_ack (tc0, b0);
288 *next0 = tcp_next_output (tc0->c_is_ip4);
289 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
295 /* 2nd: check the RST bit */
298 tcp_connection_reset (tc0);
302 /* 3rd: check security and precedence (skip) */
304 /* 4th: check the SYN bit */
307 tcp_send_reset (b0, tc0->c_is_ip4);
311 /* If PAWS passed and segment in window, save timestamp */
314 tc0->tsval_recent = tc0->opt.tsval;
315 tc0->tsval_recent_age = tcp_time_now ();
322 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
324 /* SND.UNA =< SEG.ACK =< SND.NXT */
325 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
326 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
330 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
332 * Note that although the original article, srtt and rttvar are scaled
333 * to minimize round-off errors, here we don't. Instead, we rely on
334 * better precision time measurements.
336 * TODO support us rtt resolution
339 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
345 err = mrtt - tc->srtt;
346 tc->srtt += err >> 3;
348 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
349 * The increase should be bound */
350 tc->rttvar += ((int) clib_abs (err) - (int) tc->rttvar) >> 2;
354 /* First measurement. */
356 tc->rttvar = mrtt >> 1;
360 /** Update RTT estimate and RTO timer
362 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
363 * timing. Middle boxes are known to fiddle with TCP options so we
364 * should give higher priority to ACK timing.
366 * return 1 if valid rtt 0 otherwise
369 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
373 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
374 * RTT because they're ambiguous. */
375 if (tc->rtt_seq && seq_gt (ack, tc->rtt_seq) && !tc->rto_boff)
377 mrtt = tcp_time_now () - tc->rtt_ts;
381 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
382 * snd_una, i.e., the left side of the send window:
383 * seq_lt (tc->snd_una, ack). Note: last condition could be dropped, we don't
384 * try to update rtt for dupacks */
385 else if (tcp_opts_tstamp (&tc->opt) && tc->opt.tsecr && tc->bytes_acked)
387 mrtt = tcp_time_now () - tc->opt.tsecr;
390 /* Ignore dubious measurements */
391 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
394 tcp_estimate_rtt (tc, mrtt);
396 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
402 * Dequeue bytes that have been acked and while at it update RTT estimates.
405 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
407 /* Dequeue the newly ACKed bytes */
408 stream_session_dequeue_drop (&tc->connection, tc->bytes_acked);
410 /* Update rtt and rto */
411 if (tcp_update_rtt (tc, ack))
413 /* Good ACK received and valid RTT, make sure retransmit backoff is 0 */
419 * Check if dupack as per RFC5681 Sec. 2
421 * This works only if called before updating snd_wnd.
424 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 new_snd_wnd)
426 return ((vnet_buffer (b)->tcp.ack_number == tc->snd_una)
427 && seq_gt (tc->snd_una_max, tc->snd_una)
428 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
429 && (new_snd_wnd == tc->snd_wnd));
433 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
435 sack_scoreboard_hole_t *next, *prev;
437 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
439 next = pool_elt_at_index (sb->holes, hole->next);
440 next->prev = hole->prev;
443 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
445 prev = pool_elt_at_index (sb->holes, hole->prev);
446 prev->next = hole->next;
450 sb->head = hole->next;
453 pool_put (sb->holes, hole);
456 sack_scoreboard_hole_t *
457 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
460 sack_scoreboard_hole_t *hole, *next, *prev;
463 pool_get (sb->holes, hole);
464 memset (hole, 0, sizeof (*hole));
468 hole_index = hole - sb->holes;
470 prev = scoreboard_get_hole (sb, prev_index);
473 hole->prev = prev - sb->holes;
474 hole->next = prev->next;
476 if ((next = scoreboard_next_hole (sb, hole)))
477 next->prev = hole_index;
479 prev->next = hole_index;
483 sb->head = hole_index;
484 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
485 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
492 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
494 sack_scoreboard_t *sb = &tc->sack_sb;
495 sack_block_t *blk, tmp;
496 sack_scoreboard_hole_t *hole, *next_hole, *last_hole, *new_hole;
497 u32 blk_index = 0, old_sacked_bytes, hole_index;
500 sb->last_sacked_bytes = 0;
502 old_sacked_bytes = sb->sacked_bytes;
504 if (!tcp_opts_sack (&tc->opt) && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
507 /* Remove invalid blocks */
509 while (blk < vec_end (tc->opt.sacks))
511 if (seq_lt (blk->start, blk->end)
512 && seq_gt (blk->start, tc->snd_una)
513 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_nxt))
518 vec_del1 (tc->opt.sacks, blk - tc->opt.sacks);
521 /* Add block for cumulative ack */
522 if (seq_gt (ack, tc->snd_una))
524 tmp.start = tc->snd_una;
526 vec_add1 (tc->opt.sacks, tmp);
529 if (vec_len (tc->opt.sacks) == 0)
532 /* Make sure blocks are ordered */
533 for (i = 0; i < vec_len (tc->opt.sacks); i++)
534 for (j = i + 1; j < vec_len (tc->opt.sacks); j++)
535 if (seq_lt (tc->opt.sacks[j].start, tc->opt.sacks[i].start))
537 tmp = tc->opt.sacks[i];
538 tc->opt.sacks[i] = tc->opt.sacks[j];
539 tc->opt.sacks[j] = tmp;
542 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
544 /* If no holes, insert the first that covers all outstanding bytes */
545 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
546 tc->snd_una, tc->snd_una_max);
547 sb->tail = scoreboard_hole_index (sb, last_hole);
551 /* If we have holes but snd_una_max is beyond the last hole, update
553 tmp = tc->opt.sacks[vec_len (tc->opt.sacks) - 1];
554 last_hole = scoreboard_last_hole (sb);
555 if (seq_gt (tc->snd_una_max, sb->max_byte_sacked)
556 && seq_gt (tc->snd_una_max, last_hole->end))
557 last_hole->end = tc->snd_una_max;
560 /* Walk the holes with the SACK blocks */
561 hole = pool_elt_at_index (sb->holes, sb->head);
562 while (hole && blk_index < vec_len (tc->opt.sacks))
564 blk = &tc->opt.sacks[blk_index];
566 if (seq_leq (blk->start, hole->start))
568 /* Block covers hole. Remove hole */
569 if (seq_geq (blk->end, hole->end))
571 next_hole = scoreboard_next_hole (sb, hole);
573 /* Byte accounting */
574 if (seq_leq (hole->end, ack))
576 /* Bytes lost because snd_wnd left edge advances */
577 if (next_hole && seq_leq (next_hole->start, ack))
578 sb->sacked_bytes -= next_hole->start - hole->end;
580 sb->sacked_bytes -= ack - hole->end;
584 sb->sacked_bytes += scoreboard_hole_bytes (hole);
587 /* snd_una needs to be advanced */
588 if (seq_geq (ack, hole->end))
590 if (next_hole && seq_lt (ack, next_hole->start))
591 sb->snd_una_adv = next_hole->start - ack;
593 sb->snd_una_adv = sb->max_byte_sacked - ack;
595 /* all these can be delivered */
596 sb->sacked_bytes -= sb->snd_una_adv;
599 /* About to remove last hole */
600 if (hole == last_hole)
602 sb->tail = hole->prev;
603 last_hole = scoreboard_last_hole (sb);
604 /* keep track of max byte sacked in case the last hole
606 if (seq_gt (hole->end, sb->max_byte_sacked))
607 sb->max_byte_sacked = hole->end;
609 scoreboard_remove_hole (sb, hole);
612 /* Partial 'head' overlap */
615 if (seq_gt (blk->end, hole->start))
617 sb->sacked_bytes += blk->end - hole->start;
618 hole->start = blk->end;
625 /* Hole must be split */
626 if (seq_lt (blk->end, hole->end))
628 sb->sacked_bytes += blk->end - blk->start;
629 hole_index = scoreboard_hole_index (sb, hole);
630 new_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
633 /* Pool might've moved */
634 hole = scoreboard_get_hole (sb, hole_index);
635 hole->end = blk->start;
637 /* New or split of tail */
638 if ((last_hole->end == new_hole->end)
639 || seq_lt (last_hole->end, new_hole->start))
641 last_hole = new_hole;
642 sb->tail = scoreboard_hole_index (sb, new_hole);
646 hole = scoreboard_next_hole (sb, hole);
650 sb->sacked_bytes += hole->end - blk->start;
651 hole->end = blk->start;
652 hole = scoreboard_next_hole (sb, hole);
657 sb->last_sacked_bytes = sb->sacked_bytes + sb->snd_una_adv
663 * If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
664 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
666 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
668 if (seq_lt (tc->snd_wl1, seq)
669 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
671 tc->snd_wnd = snd_wnd;
674 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
679 tcp_cc_congestion (tcp_connection_t * tc)
681 tc->snd_congestion = tc->snd_nxt;
682 tc->cc_algo->congestion (tc);
683 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
687 tcp_cc_recover (tcp_connection_t * tc)
689 tc->cc_algo->recovered (tc);
693 tc->snd_nxt = tc->snd_una;
695 tc->cc_algo->rcv_ack (tc);
696 tc->tsecr_last_ack = tc->opt.tsecr;
698 tcp_fastrecovery_1_smss_off (tc);
699 tcp_fastrecovery_off (tc);
701 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
705 tcp_cc_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b)
709 if (tcp_in_recovery (tc))
711 partial_ack = seq_lt (tc->snd_una, tc->snd_congestion);
714 /* Clear retransmitted bytes. */
719 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
721 /* Clear retransmitted bytes. XXX should we clear all? */
723 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
725 /* In case snd_nxt is still in the past and output tries to
726 * shove some new bytes */
727 tc->snd_nxt = tc->snd_una;
729 /* XXX need proper RFC6675 support */
730 if (tc->sack_sb.last_sacked_bytes)
732 tcp_fast_retransmit (tc);
736 /* Retransmit first unacked segment */
737 tcp_retransmit_first_unacked (tc);
738 /* If window allows, send 1 SMSS of new data */
739 if (seq_lt (tc->snd_nxt, tc->snd_congestion))
740 tc->snd_nxt = tc->snd_congestion;
746 tc->cc_algo->rcv_ack (tc);
747 tc->tsecr_last_ack = tc->opt.tsecr;
753 tcp_cc_rcv_dupack (tcp_connection_t * tc, u32 ack)
755 // ASSERT (seq_geq(tc->snd_una, ack));
758 if (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
760 /* RFC6582 NewReno heuristic to avoid multiple fast retransmits */
761 if (tc->opt.tsecr != tc->tsecr_last_ack)
767 tcp_fastrecovery_on (tc);
769 /* Handle congestion and dupack */
770 tcp_cc_congestion (tc);
771 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
773 tcp_fast_retransmit (tc);
775 /* Post retransmit update cwnd to ssthresh and account for the
776 * three segments that have left the network and should've been
777 * buffered at the receiver */
778 tc->cwnd = tc->ssthresh + TCP_DUPACK_THRESHOLD * tc->snd_mss;
780 else if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD)
782 ASSERT (tcp_in_fastrecovery (tc));
784 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
789 tcp_cc_init (tcp_connection_t * tc)
791 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
792 tc->cc_algo->init (tc);
796 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
797 tcp_header_t * th, u32 * next, u32 * error)
801 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
802 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt))
804 /* If we have outstanding data and this is within the window, accept it,
805 * probably retransmit has timed out. Otherwise ACK segment and then
807 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
809 tcp_make_ack (tc, b);
810 *next = tcp_next_output (tc->c_is_ip4);
811 *error = TCP_ERROR_ACK_INVALID;
812 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
813 vnet_buffer (b)->tcp.ack_number);
817 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
818 *error = TCP_ERROR_ACK_FUTURE;
819 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
820 vnet_buffer (b)->tcp.ack_number);
823 /* If old ACK, probably it's an old dupack */
824 if (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
826 *error = TCP_ERROR_ACK_OLD;
827 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
828 vnet_buffer (b)->tcp.ack_number);
829 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
831 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
832 tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number);
837 if (tcp_opts_sack_permitted (&tc->opt))
838 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
840 new_snd_wnd = clib_net_to_host_u16 (th->window) << tc->snd_wscale;
842 if (tcp_ack_is_dupack (tc, b, new_snd_wnd))
844 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
845 tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number);
846 *error = TCP_ERROR_ACK_DUP;
854 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
855 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
857 /* Dequeue ACKed data and update RTT */
858 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
859 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
860 vnet_buffer (b)->tcp.ack_number, new_snd_wnd);
862 /* If some of our sent bytes have been acked, update cc and retransmit
866 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc, vnet_buffer (b)->tcp.ack_number);
868 /* Updates congestion control (slow start/congestion avoidance) */
869 tcp_cc_rcv_ack (tc, b);
871 /* If everything has been acked, stop retransmit timer
872 * otherwise update */
873 if (tc->snd_una == tc->snd_una_max)
874 tcp_retransmit_timer_reset (tc);
876 tcp_retransmit_timer_update (tc);
883 * Build SACK list as per RFC2018.
885 * Makes sure the first block contains the segment that generated the current
886 * ACK and the following ones are the ones most recently reported in SACK
889 * @param tc TCP connection for which the SACK list is updated
890 * @param start Start sequence number of the newest SACK block
891 * @param end End sequence of the newest SACK block
894 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
896 sack_block_t *new_list = 0, block;
899 /* If the first segment is ooo add it to the list. Last write might've moved
900 * rcv_nxt over the first segment. */
901 if (seq_lt (tc->rcv_nxt, start))
905 vec_add1 (new_list, block);
908 /* Find the blocks still worth keeping. */
909 for (i = 0; i < vec_len (tc->snd_sacks); i++)
912 * 1) rcv_nxt advanced beyond current block OR
913 * 2) Segment overlapped by the first segment, i.e., it has been merged
915 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt)
916 || seq_leq (tc->snd_sacks[i].start, end))
919 /* Save to new SACK list. */
920 vec_add1 (new_list, tc->snd_sacks[i]);
923 ASSERT (vec_len (new_list) < TCP_MAX_SACK_BLOCKS);
925 /* Replace old vector with new one */
926 vec_free (tc->snd_sacks);
927 tc->snd_sacks = new_list;
930 /** Enqueue data for delivery to application */
932 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
937 /* Pure ACK. Update rcv_nxt and be done. */
938 if (PREDICT_FALSE (data_len == 0))
940 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
941 return TCP_ERROR_PURE_ACK;
944 written = stream_session_enqueue_data (&tc->connection,
945 vlib_buffer_get_current (b),
946 data_len, 1 /* queue event */ );
948 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
951 if (PREDICT_TRUE (written == data_len))
953 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
955 /* If more data written than expected, account for out-of-order bytes. */
956 else if (written > data_len)
958 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end + written - data_len;
960 /* Send ACK confirming the update */
961 tc->flags |= TCP_CONN_SNDACK;
963 else if (written > 0)
965 /* We've written something but FIFO is probably full now */
966 tc->rcv_nxt += written;
968 /* Depending on how fast the app is, all remaining buffers in burst will
969 * not be enqueued. Should we inform peer of the damage? XXX */
970 return TCP_ERROR_PARTIALLY_ENQUEUED;
974 return TCP_ERROR_FIFO_FULL;
977 /* Update SACK list if need be */
978 if (tcp_opts_sack_permitted (&tc->opt))
980 /* Remove SACK blocks that have been delivered */
981 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
984 return TCP_ERROR_ENQUEUED;
987 /** Enqueue out-of-order data */
989 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
992 stream_session_t *s0;
996 /* Pure ACK. Do nothing */
997 if (PREDICT_FALSE (data_len == 0))
999 return TCP_ERROR_PURE_ACK;
1002 s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
1003 seq = vnet_buffer (b)->tcp.seq_number;
1004 offset = seq - tc->rcv_nxt;
1006 rv = svm_fifo_enqueue_with_offset (s0->server_rx_fifo, s0->pid, offset,
1007 data_len, vlib_buffer_get_current (b));
1009 /* Nothing written */
1012 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1013 return TCP_ERROR_FIFO_FULL;
1016 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1018 /* Update SACK list if in use */
1019 if (tcp_opts_sack_permitted (&tc->opt))
1021 ooo_segment_t *newest;
1024 /* Get the newest segment from the fifo */
1025 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1026 start = tc->rcv_nxt + ooo_segment_offset (s0->server_rx_fifo, newest);
1027 end = tc->rcv_nxt + ooo_segment_end_offset (s0->server_rx_fifo, newest);
1029 tcp_update_sack_list (tc, start, end);
1032 return TCP_ERROR_ENQUEUED;
1036 * Check if ACK could be delayed. If ack can be delayed, it should return
1037 * true for a full frame. If we're always acking return 0.
1040 tcp_can_delack (tcp_connection_t * tc)
1042 /* Send ack if ... */
1044 /* just sent a rcv wnd 0 */
1045 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1046 /* constrained to send ack */
1047 || (tc->flags & TCP_CONN_SNDACK) != 0
1048 /* we're almost out of tx wnd */
1049 || tcp_available_snd_space (tc) < 2 * tc->snd_mss)
1056 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1057 u16 n_data_bytes, u32 * next0)
1061 /* Handle out-of-order data */
1062 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1064 /* Old sequence numbers allowed through because they overlapped
1066 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1068 error = TCP_ERROR_SEGMENT_OLD;
1069 *next0 = TCP_NEXT_DROP;
1073 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1075 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1076 * cwnd on remote peer when congested 2) acks leaving should have the
1077 * latest rcv_wnd since the burst may eaten up all of it, so only the
1078 * old ones could be filtered.
1081 /* RFC2581: Send DUPACK for fast retransmit */
1082 tcp_make_ack (tc, b);
1083 *next0 = tcp_next_output (tc->c_is_ip4);
1085 /* Mark as DUPACK. We may filter these in output if
1086 * the burst fills the holes. */
1088 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1090 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1094 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1095 * segments can be enqueued after fifo tail offset changes. */
1096 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1098 if (n_data_bytes == 0)
1100 *next0 = TCP_NEXT_DROP;
1104 if (PREDICT_FALSE (error == TCP_ERROR_FIFO_FULL))
1105 *next0 = TCP_NEXT_DROP;
1107 /* Check if ACK can be delayed */
1108 if (!tcp_can_delack (tc))
1110 /* Nothing to do for pure ACKs XXX */
1111 if (n_data_bytes == 0)
1114 *next0 = tcp_next_output (tc->c_is_ip4);
1115 tcp_make_ack (tc, b);
1119 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1120 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1128 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1130 if (PREDICT_TRUE (!val))
1134 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1136 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1140 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1141 vlib_frame_t * from_frame, int is_ip4)
1143 u32 n_left_from, next_index, *from, *to_next;
1144 u32 my_thread_index = vm->cpu_index, errors = 0;
1145 tcp_main_t *tm = vnet_get_tcp_main ();
1147 from = vlib_frame_vector_args (from_frame);
1148 n_left_from = from_frame->n_vectors;
1150 next_index = node->cached_next_index;
1152 while (n_left_from > 0)
1156 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1158 while (n_left_from > 0 && n_left_to_next > 0)
1162 tcp_header_t *th0 = 0;
1163 tcp_connection_t *tc0;
1166 u32 n_advance_bytes0, n_data_bytes0;
1167 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1174 n_left_to_next -= 1;
1176 b0 = vlib_get_buffer (vm, bi0);
1177 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1180 if (PREDICT_FALSE (tc0 == 0))
1182 error0 = TCP_ERROR_INVALID_CONNECTION;
1186 /* Checksum computed by ipx_local no need to compute again */
1190 ip40 = vlib_buffer_get_current (b0);
1191 th0 = ip4_next_header (ip40);
1192 n_advance_bytes0 = (ip4_header_bytes (ip40)
1193 + tcp_header_bytes (th0));
1194 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
1199 ip60 = vlib_buffer_get_current (b0);
1200 th0 = ip6_next_header (ip60);
1201 n_advance_bytes0 = tcp_header_bytes (th0);
1202 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
1204 n_advance_bytes0 += sizeof (ip60[0]);
1207 /* SYNs, FINs and data consume sequence numbers */
1208 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1209 + tcp_is_syn (th0) + tcp_is_fin (th0) + n_data_bytes0;
1211 /* TODO header prediction fast path */
1213 /* 1-4: check SEQ, RST, SYN */
1214 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1216 error0 = TCP_ERROR_SEGMENT_INVALID;
1217 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1218 vnet_buffer (b0)->tcp.seq_number,
1219 vnet_buffer (b0)->tcp.seq_end);
1223 /* 5: check the ACK field */
1224 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1229 /* 6: check the URG bit TODO */
1231 /* 7: process the segment text */
1233 vlib_buffer_advance (b0, n_advance_bytes0);
1234 error0 = tcp_segment_rcv (tm, tc0, b0, n_data_bytes0, &next0);
1236 /* 8: check the FIN bit */
1239 /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
1240 * wait for session to call close. To avoid lingering
1241 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1242 tc0->state = TCP_STATE_CLOSE_WAIT;
1243 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1244 stream_session_disconnect_notify (&tc0->connection);
1245 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1249 b0->error = node->errors[error0];
1250 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1255 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1256 n_left_to_next, bi0, next0);
1259 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1262 errors = session_manager_flush_enqueue_events (my_thread_index);
1263 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1265 return from_frame->n_vectors;
1269 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1270 vlib_frame_t * from_frame)
1272 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1276 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1277 vlib_frame_t * from_frame)
1279 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1283 VLIB_REGISTER_NODE (tcp4_established_node) =
1285 .function = tcp4_established,
1286 .name = "tcp4-established",
1287 /* Takes a vector of packets. */
1288 .vector_size = sizeof (u32),
1289 .n_errors = TCP_N_ERROR,
1290 .error_strings = tcp_error_strings,
1291 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1294 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1295 foreach_tcp_state_next
1301 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1304 VLIB_REGISTER_NODE (tcp6_established_node) =
1306 .function = tcp6_established,
1307 .name = "tcp6-established",
1308 /* Takes a vector of packets. */
1309 .vector_size = sizeof (u32),
1310 .n_errors = TCP_N_ERROR,
1311 .error_strings = tcp_error_strings,
1312 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1315 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1316 foreach_tcp_state_next
1323 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1325 vlib_node_registration_t tcp4_syn_sent_node;
1326 vlib_node_registration_t tcp6_syn_sent_node;
1329 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1330 vlib_frame_t * from_frame, int is_ip4)
1332 tcp_main_t *tm = vnet_get_tcp_main ();
1333 u32 n_left_from, next_index, *from, *to_next;
1334 u32 my_thread_index = vm->cpu_index, errors = 0;
1335 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
1337 from = vlib_frame_vector_args (from_frame);
1338 n_left_from = from_frame->n_vectors;
1340 next_index = node->cached_next_index;
1342 while (n_left_from > 0)
1346 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1348 while (n_left_from > 0 && n_left_to_next > 0)
1350 u32 bi0, ack0, seq0;
1352 tcp_header_t *tcp0 = 0;
1353 tcp_connection_t *tc0;
1356 u32 n_advance_bytes0, n_data_bytes0;
1357 tcp_connection_t *new_tc0;
1358 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1365 n_left_to_next -= 1;
1367 b0 = vlib_get_buffer (vm, bi0);
1369 tcp_half_open_connection_get (vnet_buffer (b0)->
1370 tcp.connection_index);
1372 ack0 = vnet_buffer (b0)->tcp.ack_number;
1373 seq0 = vnet_buffer (b0)->tcp.seq_number;
1375 /* Checksum computed by ipx_local no need to compute again */
1379 ip40 = vlib_buffer_get_current (b0);
1380 tcp0 = ip4_next_header (ip40);
1381 n_advance_bytes0 = (ip4_header_bytes (ip40)
1382 + tcp_header_bytes (tcp0));
1383 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
1388 ip60 = vlib_buffer_get_current (b0);
1389 tcp0 = ip6_next_header (ip60);
1390 n_advance_bytes0 = tcp_header_bytes (tcp0);
1391 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
1393 n_advance_bytes0 += sizeof (ip60[0]);
1397 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1400 /* SYNs, FINs and data consume sequence numbers */
1401 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1402 + tcp_is_fin (tcp0) + n_data_bytes0;
1405 * 1. check the ACK bit
1409 * If the ACK bit is set
1410 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
1411 * the RST bit is set, if so drop the segment and return)
1412 * <SEQ=SEG.ACK><CTL=RST>
1413 * and discard the segment. Return.
1414 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
1418 if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt)
1420 if (!tcp_rst (tcp0))
1421 tcp_send_reset (b0, is_ip4);
1426 /* Make sure ACK is valid */
1427 if (tc0->snd_una > ack0)
1432 * 2. check the RST bit
1437 /* If ACK is acceptable, signal client that peer is not
1438 * willing to accept connection and drop connection*/
1441 stream_session_connect_notify (&tc0->connection, sst,
1443 tcp_connection_cleanup (tc0);
1449 * 3. check the security and precedence (skipped)
1453 * 4. check the SYN bit
1456 /* No SYN flag. Drop. */
1457 if (!tcp_syn (tcp0))
1460 /* Stop connection establishment and retransmit timers */
1461 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
1462 tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT_SYN);
1464 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
1465 * current thread pool. */
1466 pool_get (tm->connections[my_thread_index], new_tc0);
1467 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
1469 new_tc0->c_thread_index = my_thread_index;
1471 /* Cleanup half-open connection XXX lock */
1472 pool_put (tm->half_open_connections, tc0);
1474 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
1475 new_tc0->irs = seq0;
1478 tcp_options_parse (tcp0, &new_tc0->opt);
1480 if (tcp_opts_tstamp (&new_tc0->opt))
1482 new_tc0->tsval_recent = new_tc0->opt.tsval;
1483 new_tc0->tsval_recent_age = tcp_time_now ();
1486 if (tcp_opts_wscale (&new_tc0->opt))
1487 new_tc0->snd_wscale = new_tc0->opt.wscale;
1490 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
1491 new_tc0->snd_wl1 = seq0;
1492 new_tc0->snd_wl2 = ack0;
1494 tcp_connection_init_vars (new_tc0);
1496 /* SYN-ACK: See if we can switch to ESTABLISHED state */
1499 /* Our SYN is ACKed: we have iss < ack = snd_una */
1501 /* TODO Dequeue acknowledged segments if we support Fast Open */
1502 new_tc0->snd_una = ack0;
1503 new_tc0->state = TCP_STATE_ESTABLISHED;
1505 /* Make sure las is initialized for the wnd computation */
1506 new_tc0->rcv_las = new_tc0->rcv_nxt;
1508 /* Notify app that we have connection */
1509 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1511 /* Make sure after data segment processing ACK is sent */
1512 new_tc0->flags |= TCP_CONN_SNDACK;
1514 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
1517 new_tc0->state = TCP_STATE_SYN_RCVD;
1519 /* Notify app that we have connection */
1520 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1522 tcp_make_synack (new_tc0, b0);
1523 next0 = tcp_next_output (is_ip4);
1528 /* Read data, if any */
1532 tcp_segment_rcv (tm, new_tc0, b0, n_data_bytes0, &next0);
1533 if (error0 == TCP_ERROR_PURE_ACK)
1534 error0 = TCP_ERROR_SYN_ACKS_RCVD;
1538 tcp_make_ack (new_tc0, b0);
1539 next0 = tcp_next_output (new_tc0->c_is_ip4);
1544 b0->error = error0 ? node->errors[error0] : 0;
1545 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1550 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1551 n_left_to_next, bi0, next0);
1554 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1557 errors = session_manager_flush_enqueue_events (my_thread_index);
1561 vlib_node_increment_counter (vm, tcp4_established_node.index,
1562 TCP_ERROR_EVENT_FIFO_FULL, errors);
1564 vlib_node_increment_counter (vm, tcp6_established_node.index,
1565 TCP_ERROR_EVENT_FIFO_FULL, errors);
1568 return from_frame->n_vectors;
1572 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
1573 vlib_frame_t * from_frame)
1575 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1579 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
1580 vlib_frame_t * from_frame)
1582 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1586 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
1588 .function = tcp4_syn_sent,
1589 .name = "tcp4-syn-sent",
1590 /* Takes a vector of packets. */
1591 .vector_size = sizeof (u32),
1592 .n_errors = TCP_N_ERROR,
1593 .error_strings = tcp_error_strings,
1594 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1597 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1598 foreach_tcp_state_next
1604 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
1607 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
1609 .function = tcp6_syn_sent_rcv,
1610 .name = "tcp6-syn-sent",
1611 /* Takes a vector of packets. */
1612 .vector_size = sizeof (u32),
1613 .n_errors = TCP_N_ERROR,
1614 .error_strings = tcp_error_strings,
1615 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1618 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1619 foreach_tcp_state_next
1625 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
1627 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
1628 * as per RFC793 p. 64
1631 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1632 vlib_frame_t * from_frame, int is_ip4)
1634 tcp_main_t *tm = vnet_get_tcp_main ();
1635 u32 n_left_from, next_index, *from, *to_next;
1636 u32 my_thread_index = vm->cpu_index, errors = 0;
1638 from = vlib_frame_vector_args (from_frame);
1639 n_left_from = from_frame->n_vectors;
1641 next_index = node->cached_next_index;
1643 while (n_left_from > 0)
1647 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1649 while (n_left_from > 0 && n_left_to_next > 0)
1653 tcp_header_t *tcp0 = 0;
1654 tcp_connection_t *tc0;
1657 u32 n_advance_bytes0, n_data_bytes0;
1658 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1665 n_left_to_next -= 1;
1667 b0 = vlib_get_buffer (vm, bi0);
1668 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1670 if (PREDICT_FALSE (tc0 == 0))
1672 error0 = TCP_ERROR_INVALID_CONNECTION;
1676 /* Checksum computed by ipx_local no need to compute again */
1680 ip40 = vlib_buffer_get_current (b0);
1681 tcp0 = ip4_next_header (ip40);
1682 n_advance_bytes0 = (ip4_header_bytes (ip40)
1683 + tcp_header_bytes (tcp0));
1684 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
1689 ip60 = vlib_buffer_get_current (b0);
1690 tcp0 = ip6_next_header (ip60);
1691 n_advance_bytes0 = tcp_header_bytes (tcp0);
1692 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
1694 n_advance_bytes0 += sizeof (ip60[0]);
1697 /* SYNs, FINs and data consume sequence numbers */
1698 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1699 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0) + n_data_bytes0;
1702 * Special treatment for CLOSED
1706 case TCP_STATE_CLOSED:
1712 * For all other states (except LISTEN)
1715 /* 1-4: check SEQ, RST, SYN */
1717 (tcp_segment_validate (vm, tc0, b0, tcp0, &next0)))
1719 error0 = TCP_ERROR_SEGMENT_INVALID;
1723 /* 5: check the ACK field */
1726 case TCP_STATE_SYN_RCVD:
1728 * If the segment acknowledgment is not acceptable, form a
1730 * <SEQ=SEG.ACK><CTL=RST>
1733 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
1735 tcp_send_reset (b0, is_ip4);
1738 /* Switch state to ESTABLISHED */
1739 tc0->state = TCP_STATE_ESTABLISHED;
1741 /* Initialize session variables */
1742 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
1743 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
1745 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
1746 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
1748 /* Shoulder tap the server */
1749 stream_session_accept_notify (&tc0->connection);
1751 /* Reset SYN-ACK retransmit timer */
1752 tcp_retransmit_timer_reset (tc0);
1754 case TCP_STATE_ESTABLISHED:
1755 /* We can get packets in established state here because they
1756 * were enqueued before state change */
1757 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1761 case TCP_STATE_FIN_WAIT_1:
1762 /* In addition to the processing for the ESTABLISHED state, if
1763 * our FIN is now acknowledged then enter FIN-WAIT-2 and
1764 * continue processing in that state. */
1765 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1768 /* If FIN is ACKed */
1769 if (tc0->snd_una == tc0->snd_una_max)
1771 tc0->state = TCP_STATE_FIN_WAIT_2;
1772 /* Stop all timers, 2MSL will be set lower */
1773 tcp_connection_timers_reset (tc0);
1776 case TCP_STATE_FIN_WAIT_2:
1777 /* In addition to the processing for the ESTABLISHED state, if
1778 * the retransmission queue is empty, the user's CLOSE can be
1779 * acknowledged ("ok") but do not delete the TCB. */
1780 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1782 /* check if rtx queue is empty and ack CLOSE TODO */
1784 case TCP_STATE_CLOSE_WAIT:
1785 /* Do the same processing as for the ESTABLISHED state. */
1786 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1789 case TCP_STATE_CLOSING:
1790 /* In addition to the processing for the ESTABLISHED state, if
1791 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
1792 * otherwise ignore the segment. */
1793 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1796 /* XXX test that send queue empty */
1797 tc0->state = TCP_STATE_TIME_WAIT;
1801 case TCP_STATE_LAST_ACK:
1802 /* The only thing that can arrive in this state is an
1803 * acknowledgment of our FIN. If our FIN is now acknowledged,
1804 * delete the TCB, enter the CLOSED state, and return. */
1806 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
1809 tc0->state = TCP_STATE_CLOSED;
1811 /* Don't delete the connection/session yet. Instead, wait a
1812 * reasonable amount of time until the pipes are cleared. In
1813 * particular, this makes sure that we won't have dead sessions
1814 * when processing events on the tx path */
1815 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
1817 /* Stop retransmit */
1818 tcp_retransmit_timer_reset (tc0);
1823 case TCP_STATE_TIME_WAIT:
1824 /* The only thing that can arrive in this state is a
1825 * retransmission of the remote FIN. Acknowledge it, and restart
1826 * the 2 MSL timeout. */
1835 /* 6: check the URG bit TODO */
1837 /* 7: process the segment text */
1840 case TCP_STATE_ESTABLISHED:
1841 case TCP_STATE_FIN_WAIT_1:
1842 case TCP_STATE_FIN_WAIT_2:
1843 error0 = tcp_segment_rcv (tm, tc0, b0, n_data_bytes0, &next0);
1845 case TCP_STATE_CLOSE_WAIT:
1846 case TCP_STATE_CLOSING:
1847 case TCP_STATE_LAST_ACK:
1848 case TCP_STATE_TIME_WAIT:
1849 /* This should not occur, since a FIN has been received from the
1850 * remote side. Ignore the segment text. */
1854 /* 8: check the FIN bit */
1855 if (!tcp_fin (tcp0))
1860 case TCP_STATE_ESTABLISHED:
1861 case TCP_STATE_SYN_RCVD:
1862 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
1863 tcp_connection_timers_reset (tc0);
1864 tcp_make_fin (tc0, b0);
1865 next0 = tcp_next_output (tc0->c_is_ip4);
1866 stream_session_disconnect_notify (&tc0->connection);
1867 tc0->state = TCP_STATE_CLOSE_WAIT;
1869 case TCP_STATE_CLOSE_WAIT:
1870 case TCP_STATE_CLOSING:
1871 case TCP_STATE_LAST_ACK:
1874 case TCP_STATE_FIN_WAIT_1:
1875 tc0->state = TCP_STATE_TIME_WAIT;
1876 tcp_connection_timers_reset (tc0);
1877 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
1879 case TCP_STATE_FIN_WAIT_2:
1880 /* Got FIN, send ACK! */
1881 tc0->state = TCP_STATE_TIME_WAIT;
1882 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1883 tcp_make_ack (tc0, b0);
1884 next0 = tcp_next_output (is_ip4);
1886 case TCP_STATE_TIME_WAIT:
1887 /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
1890 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
1893 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1895 b0->error = error0 ? node->errors[error0] : 0;
1898 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1903 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1904 n_left_to_next, bi0, next0);
1907 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1910 errors = session_manager_flush_enqueue_events (my_thread_index);
1914 vlib_node_increment_counter (vm, tcp4_established_node.index,
1915 TCP_ERROR_EVENT_FIFO_FULL, errors);
1917 vlib_node_increment_counter (vm, tcp6_established_node.index,
1918 TCP_ERROR_EVENT_FIFO_FULL, errors);
1921 return from_frame->n_vectors;
1925 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
1926 vlib_frame_t * from_frame)
1928 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1932 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
1933 vlib_frame_t * from_frame)
1935 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1939 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
1941 .function = tcp4_rcv_process,
1942 .name = "tcp4-rcv-process",
1943 /* Takes a vector of packets. */
1944 .vector_size = sizeof (u32),
1945 .n_errors = TCP_N_ERROR,
1946 .error_strings = tcp_error_strings,
1947 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
1950 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
1951 foreach_tcp_state_next
1957 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
1960 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
1962 .function = tcp6_rcv_process,
1963 .name = "tcp6-rcv-process",
1964 /* Takes a vector of packets. */
1965 .vector_size = sizeof (u32),
1966 .n_errors = TCP_N_ERROR,
1967 .error_strings = tcp_error_strings,
1968 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
1971 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
1972 foreach_tcp_state_next
1978 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
1980 vlib_node_registration_t tcp4_listen_node;
1981 vlib_node_registration_t tcp6_listen_node;
1984 * LISTEN state processing as per RFC 793 p. 65
1987 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1988 vlib_frame_t * from_frame, int is_ip4)
1990 u32 n_left_from, next_index, *from, *to_next;
1991 u32 my_thread_index = vm->cpu_index;
1992 tcp_main_t *tm = vnet_get_tcp_main ();
1993 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
1995 from = vlib_frame_vector_args (from_frame);
1996 n_left_from = from_frame->n_vectors;
1998 next_index = node->cached_next_index;
2000 while (n_left_from > 0)
2004 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2006 while (n_left_from > 0 && n_left_to_next > 0)
2010 tcp_header_t *th0 = 0;
2011 tcp_connection_t *lc0;
2014 tcp_connection_t *child0;
2015 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2022 n_left_to_next -= 1;
2024 b0 = vlib_get_buffer (vm, bi0);
2025 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2029 ip40 = vlib_buffer_get_current (b0);
2030 th0 = ip4_next_header (ip40);
2034 ip60 = vlib_buffer_get_current (b0);
2035 th0 = ip6_next_header (ip60);
2038 /* Create child session. For syn-flood protection use filter */
2040 /* 1. first check for an RST */
2044 /* 2. second check for an ACK */
2047 tcp_send_reset (b0, is_ip4);
2051 /* 3. check for a SYN (did that already) */
2053 /* Create child session and send SYN-ACK */
2054 pool_get (tm->connections[my_thread_index], child0);
2055 memset (child0, 0, sizeof (*child0));
2057 child0->c_c_index = child0 - tm->connections[my_thread_index];
2058 child0->c_lcl_port = lc0->c_lcl_port;
2059 child0->c_rmt_port = th0->src_port;
2060 child0->c_is_ip4 = is_ip4;
2061 child0->c_thread_index = my_thread_index;
2065 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2066 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2070 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2071 sizeof (ip6_address_t));
2072 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2073 sizeof (ip6_address_t));
2076 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2079 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2083 tcp_options_parse (th0, &child0->opt);
2085 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2086 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2087 child0->state = TCP_STATE_SYN_RCVD;
2089 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2090 * segments are used to initialize PAWS. */
2091 if (tcp_opts_tstamp (&child0->opt))
2093 child0->tsval_recent = child0->opt.tsval;
2094 child0->tsval_recent_age = tcp_time_now ();
2097 if (tcp_opts_wscale (&child0->opt))
2098 child0->snd_wscale = child0->opt.wscale;
2101 child0->snd_wnd = clib_net_to_host_u16 (th0->window);
2102 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2103 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2105 tcp_connection_init_vars (child0);
2107 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0);
2109 /* Reuse buffer to make syn-ack and send */
2110 tcp_make_synack (child0, b0);
2111 next0 = tcp_next_output (is_ip4);
2114 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2119 b0->error = node->errors[error0];
2121 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2122 n_left_to_next, bi0, next0);
2125 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2127 return from_frame->n_vectors;
2131 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2132 vlib_frame_t * from_frame)
2134 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2138 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2139 vlib_frame_t * from_frame)
2141 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2145 VLIB_REGISTER_NODE (tcp4_listen_node) =
2147 .function = tcp4_listen,
2148 .name = "tcp4-listen",
2149 /* Takes a vector of packets. */
2150 .vector_size = sizeof (u32),
2151 .n_errors = TCP_N_ERROR,
2152 .error_strings = tcp_error_strings,
2153 .n_next_nodes = TCP_LISTEN_N_NEXT,
2156 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2157 foreach_tcp_state_next
2163 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2166 VLIB_REGISTER_NODE (tcp6_listen_node) =
2168 .function = tcp6_listen,
2169 .name = "tcp6-listen",
2170 /* Takes a vector of packets. */
2171 .vector_size = sizeof (u32),
2172 .n_errors = TCP_N_ERROR,
2173 .error_strings = tcp_error_strings,
2174 .n_next_nodes = TCP_LISTEN_N_NEXT,
2177 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2178 foreach_tcp_state_next
2184 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2186 vlib_node_registration_t tcp4_input_node;
2187 vlib_node_registration_t tcp6_input_node;
2189 typedef enum _tcp_input_next
2191 TCP_INPUT_NEXT_DROP,
2192 TCP_INPUT_NEXT_LISTEN,
2193 TCP_INPUT_NEXT_RCV_PROCESS,
2194 TCP_INPUT_NEXT_SYN_SENT,
2195 TCP_INPUT_NEXT_ESTABLISHED,
2196 TCP_INPUT_NEXT_RESET,
2200 #define foreach_tcp4_input_next \
2201 _ (DROP, "error-drop") \
2202 _ (LISTEN, "tcp4-listen") \
2203 _ (RCV_PROCESS, "tcp4-rcv-process") \
2204 _ (SYN_SENT, "tcp4-syn-sent") \
2205 _ (ESTABLISHED, "tcp4-established") \
2206 _ (RESET, "tcp4-reset")
2208 #define foreach_tcp6_input_next \
2209 _ (DROP, "error-drop") \
2210 _ (LISTEN, "tcp6-listen") \
2211 _ (RCV_PROCESS, "tcp6-rcv-process") \
2212 _ (SYN_SENT, "tcp6-syn-sent") \
2213 _ (ESTABLISHED, "tcp6-established") \
2214 _ (RESET, "tcp6-reset")
2224 format_tcp_rx_trace (u8 * s, va_list * args)
2226 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2227 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2228 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2230 s = format (s, "TCP: src-port %d dst-port %U%s\n",
2231 clib_net_to_host_u16 (t->src_port),
2232 clib_net_to_host_u16 (t->dst_port), format_tcp_state, t->state);
2237 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2240 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2241 vlib_frame_t * from_frame, int is_ip4)
2243 u32 n_left_from, next_index, *from, *to_next;
2244 u32 my_thread_index = vm->cpu_index;
2245 tcp_main_t *tm = vnet_get_tcp_main ();
2247 from = vlib_frame_vector_args (from_frame);
2248 n_left_from = from_frame->n_vectors;
2250 next_index = node->cached_next_index;
2252 while (n_left_from > 0)
2256 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2258 while (n_left_from > 0 && n_left_to_next > 0)
2262 tcp_header_t *tcp0 = 0;
2263 tcp_connection_t *tc0;
2266 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2274 n_left_to_next -= 1;
2276 b0 = vlib_get_buffer (vm, bi0);
2277 vnet_buffer (b0)->tcp.flags = 0;
2281 ip40 = vlib_buffer_get_current (b0);
2282 tcp0 = ip4_next_header (ip40);
2284 /* lookup session */
2286 (tcp_connection_t *)
2287 stream_session_lookup_transport4 (&ip40->dst_address,
2291 SESSION_TYPE_IP4_TCP,
2296 ip60 = vlib_buffer_get_current (b0);
2297 tcp0 = ip6_next_header (ip60);
2299 (tcp_connection_t *)
2300 stream_session_lookup_transport6 (&ip60->src_address,
2304 SESSION_TYPE_IP6_TCP,
2308 /* Session exists */
2309 if (PREDICT_TRUE (0 != tc0))
2311 /* Save connection index */
2312 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2313 vnet_buffer (b0)->tcp.seq_number =
2314 clib_net_to_host_u32 (tcp0->seq_number);
2315 vnet_buffer (b0)->tcp.ack_number =
2316 clib_net_to_host_u32 (tcp0->ack_number);
2318 flags0 = tcp0->flags & filter_flags;
2319 next0 = tm->dispatch_table[tc0->state][flags0].next;
2320 error0 = tm->dispatch_table[tc0->state][flags0].error;
2322 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH))
2324 /* Overload tcp flags to store state */
2325 vnet_buffer (b0)->tcp.flags = tc0->state;
2331 next0 = TCP_INPUT_NEXT_RESET;
2332 error0 = TCP_ERROR_NO_LISTENER;
2335 b0->error = error0 ? node->errors[error0] : 0;
2337 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2342 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2343 n_left_to_next, bi0, next0);
2346 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2349 return from_frame->n_vectors;
2353 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2354 vlib_frame_t * from_frame)
2356 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2360 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2361 vlib_frame_t * from_frame)
2363 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2367 VLIB_REGISTER_NODE (tcp4_input_node) =
2369 .function = tcp4_input,
2370 .name = "tcp4-input",
2371 /* Takes a vector of packets. */
2372 .vector_size = sizeof (u32),
2373 .n_errors = TCP_N_ERROR,
2374 .error_strings = tcp_error_strings,
2375 .n_next_nodes = TCP_INPUT_N_NEXT,
2378 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2379 foreach_tcp4_input_next
2382 .format_buffer = format_tcp_header,
2383 .format_trace = format_tcp_rx_trace,
2387 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
2390 VLIB_REGISTER_NODE (tcp6_input_node) =
2392 .function = tcp6_input,
2393 .name = "tcp6-input",
2394 /* Takes a vector of packets. */
2395 .vector_size = sizeof (u32),
2396 .n_errors = TCP_N_ERROR,
2397 .error_strings = tcp_error_strings,
2398 .n_next_nodes = TCP_INPUT_N_NEXT,
2401 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2402 foreach_tcp6_input_next
2405 .format_buffer = format_tcp_header,
2406 .format_trace = format_tcp_rx_trace,
2410 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
2412 tcp_update_time (f64 now, u32 thread_index)
2414 tcp_main_t *tm = vnet_get_tcp_main ();
2415 tw_timer_expire_timers_16t_2w_512sl (&tm->timer_wheels[thread_index], now);
2419 tcp_dispatch_table_init (tcp_main_t * tm)
2422 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
2423 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
2425 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
2426 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
2429 #define _(t,f,n,e) \
2431 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
2432 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
2435 /* SYNs for new connections -> tcp-listen. */
2436 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
2437 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
2438 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2439 /* SYN-ACK for a SYN */
2440 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2442 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2443 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2444 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2446 /* ACK for for established connection -> tcp-established. */
2447 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2448 /* FIN for for established connection -> tcp-established. */
2449 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2450 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2452 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2453 /* ACK or FIN-ACK to our FIN */
2454 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2455 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
2457 /* FIN in reply to our FIN from the other side */
2458 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2459 /* FIN confirming that the peer (app) has closed */
2460 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2461 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2463 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2468 tcp_input_init (vlib_main_t * vm)
2470 clib_error_t *error = 0;
2471 tcp_main_t *tm = vnet_get_tcp_main ();
2473 if ((error = vlib_call_init_function (vm, tcp_init)))
2476 /* Initialize dispatch table. */
2477 tcp_dispatch_table_init (tm);
2482 VLIB_INIT_FUNCTION (tcp_input_init);
2485 * fd.io coding-style-patch-verification: ON
2488 * eval: (c-set-style "gnu")