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 /* TODO Should segment be tagged? */
283 /* If not RST, send dup ack */
286 tcp_make_ack (tc0, b0);
287 *next0 = tcp_next_output (tc0->c_is_ip4);
288 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
294 /* 2nd: check the RST bit */
297 tcp_connection_reset (tc0);
301 /* 3rd: check security and precedence (skip) */
303 /* 4th: check the SYN bit */
306 tcp_send_reset (b0, tc0->c_is_ip4);
310 /* If PAWS passed and segment in window, save timestamp */
313 tc0->tsval_recent = tc0->opt.tsval;
314 tc0->tsval_recent_age = tcp_time_now ();
321 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
323 /* SND.UNA =< SEG.ACK =< SND.NXT */
324 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
325 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
329 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
331 * Note that although the original article, srtt and rttvar are scaled
332 * to minimize round-off errors, here we don't. Instead, we rely on
333 * better precision time measurements.
335 * TODO support us rtt resolution
338 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
344 err = mrtt - tc->srtt;
345 tc->srtt += err >> 3;
347 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
348 * The increase should be bound */
349 tc->rttvar += ((int) clib_abs (err) - (int) tc->rttvar) >> 2;
353 /* First measurement. */
355 tc->rttvar = mrtt >> 1;
359 /** Update RTT estimate and RTO timer
361 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
362 * timing. Middle boxes are known to fiddle with TCP options so we
363 * should give higher priority to ACK timing.
365 * return 1 if valid rtt 0 otherwise
368 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
372 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
373 * RTT because they're ambiguous. */
374 if (tc->rtt_seq && seq_gt (ack, tc->rtt_seq) && !tc->rto_boff)
376 mrtt = tcp_time_now () - tc->rtt_ts;
379 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
380 * snd_una, i.e., the left side of the send window:
381 * seq_lt (tc->snd_una, ack). Note: last condition could be dropped, we don't
382 * try to update rtt for dupacks */
383 else if (tcp_opts_tstamp (&tc->opt) && tc->opt.tsecr && tc->bytes_acked)
385 mrtt = tcp_time_now () - tc->opt.tsecr;
388 /* Ignore dubious measurements */
389 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
392 tcp_estimate_rtt (tc, mrtt);
394 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
396 /* Allow measuring of RTT and make sure boff is 0 */
404 * Dequeue bytes that have been acked and while at it update RTT estimates.
407 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
409 /* Dequeue the newly ACKed bytes */
410 stream_session_dequeue_drop (&tc->connection, tc->bytes_acked);
412 /* Update rtt and rto */
413 tcp_update_rtt (tc, ack);
417 * Check if dupack as per RFC5681 Sec. 2
419 * This works only if called before updating snd_wnd.
422 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 new_snd_wnd)
424 return ((vnet_buffer (b)->tcp.ack_number == tc->snd_una)
425 && seq_gt (tc->snd_una_max, tc->snd_una)
426 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
427 && (new_snd_wnd == tc->snd_wnd));
431 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
433 sack_scoreboard_hole_t *next, *prev;
435 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
437 next = pool_elt_at_index (sb->holes, hole->next);
438 next->prev = hole->prev;
441 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
443 prev = pool_elt_at_index (sb->holes, hole->prev);
444 prev->next = hole->next;
448 sb->head = hole->next;
451 pool_put (sb->holes, hole);
454 sack_scoreboard_hole_t *
455 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
458 sack_scoreboard_hole_t *hole, *next, *prev;
461 pool_get (sb->holes, hole);
462 memset (hole, 0, sizeof (*hole));
466 hole_index = hole - sb->holes;
468 prev = scoreboard_get_hole (sb, prev_index);
471 hole->prev = prev - sb->holes;
472 hole->next = prev->next;
474 if ((next = scoreboard_next_hole (sb, hole)))
475 next->prev = hole_index;
477 prev->next = hole_index;
481 sb->head = hole_index;
482 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
483 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
490 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
492 sack_scoreboard_t *sb = &tc->sack_sb;
493 sack_block_t *blk, tmp;
494 sack_scoreboard_hole_t *hole, *next_hole, *last_hole, *new_hole;
495 u32 blk_index = 0, old_sacked_bytes, hole_index;
498 sb->last_sacked_bytes = 0;
500 old_sacked_bytes = sb->sacked_bytes;
502 if (!tcp_opts_sack (&tc->opt) && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
505 /* Remove invalid blocks */
507 while (blk < vec_end (tc->opt.sacks))
509 if (seq_lt (blk->start, blk->end)
510 && seq_gt (blk->start, tc->snd_una)
511 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_nxt))
516 vec_del1 (tc->opt.sacks, blk - tc->opt.sacks);
519 /* Add block for cumulative ack */
520 if (seq_gt (ack, tc->snd_una))
522 tmp.start = tc->snd_una;
524 vec_add1 (tc->opt.sacks, tmp);
527 if (vec_len (tc->opt.sacks) == 0)
530 /* Make sure blocks are ordered */
531 for (i = 0; i < vec_len (tc->opt.sacks); i++)
532 for (j = i + 1; j < vec_len (tc->opt.sacks); j++)
533 if (seq_lt (tc->opt.sacks[j].start, tc->opt.sacks[i].start))
535 tmp = tc->opt.sacks[i];
536 tc->opt.sacks[i] = tc->opt.sacks[j];
537 tc->opt.sacks[j] = tmp;
540 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
542 /* If no holes, insert the first that covers all outstanding bytes */
543 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
544 tc->snd_una, tc->snd_una_max);
545 sb->tail = scoreboard_hole_index (sb, last_hole);
549 /* If we have holes but snd_una_max is beyond the last hole, update
551 tmp = tc->opt.sacks[vec_len (tc->opt.sacks) - 1];
552 last_hole = scoreboard_last_hole (sb);
553 if (seq_gt (tc->snd_una_max, sb->max_byte_sacked)
554 && seq_gt (tc->snd_una_max, last_hole->end))
555 last_hole->end = tc->snd_una_max;
558 /* Walk the holes with the SACK blocks */
559 hole = pool_elt_at_index (sb->holes, sb->head);
560 while (hole && blk_index < vec_len (tc->opt.sacks))
562 blk = &tc->opt.sacks[blk_index];
564 if (seq_leq (blk->start, hole->start))
566 /* Block covers hole. Remove hole */
567 if (seq_geq (blk->end, hole->end))
569 next_hole = scoreboard_next_hole (sb, hole);
571 /* Byte accounting */
572 if (seq_leq (hole->end, ack))
574 /* Bytes lost because snd_wnd left edge advances */
575 if (next_hole && seq_leq (next_hole->start, ack))
576 sb->sacked_bytes -= next_hole->start - hole->end;
578 sb->sacked_bytes -= ack - hole->end;
582 sb->sacked_bytes += scoreboard_hole_bytes (hole);
585 /* snd_una needs to be advanced */
586 if (seq_geq (ack, hole->end))
588 if (next_hole && seq_lt (ack, next_hole->start))
589 sb->snd_una_adv = next_hole->start - ack;
591 sb->snd_una_adv = sb->max_byte_sacked - ack;
593 /* all these can be delivered */
594 sb->sacked_bytes -= sb->snd_una_adv;
597 /* About to remove last hole */
598 if (hole == last_hole)
600 sb->tail = hole->prev;
601 last_hole = scoreboard_last_hole (sb);
602 /* keep track of max byte sacked in case the last hole
604 if (seq_gt (hole->end, sb->max_byte_sacked))
605 sb->max_byte_sacked = hole->end;
607 scoreboard_remove_hole (sb, hole);
610 /* Partial 'head' overlap */
613 if (seq_gt (blk->end, hole->start))
615 sb->sacked_bytes += blk->end - hole->start;
616 hole->start = blk->end;
623 /* Hole must be split */
624 if (seq_lt (blk->end, hole->end))
626 sb->sacked_bytes += blk->end - blk->start;
627 hole_index = scoreboard_hole_index (sb, hole);
628 new_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
631 /* Pool might've moved */
632 hole = scoreboard_get_hole (sb, hole_index);
633 hole->end = blk->start;
635 /* New or split of tail */
636 if ((last_hole->end == new_hole->end)
637 || seq_lt (last_hole->end, new_hole->start))
639 last_hole = new_hole;
640 sb->tail = scoreboard_hole_index (sb, new_hole);
644 hole = scoreboard_next_hole (sb, hole);
648 sb->sacked_bytes += hole->end - blk->start;
649 hole->end = blk->start;
650 hole = scoreboard_next_hole (sb, hole);
655 sb->last_sacked_bytes = sb->sacked_bytes + sb->snd_una_adv
661 * If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
662 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
664 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
666 if (seq_lt (tc->snd_wl1, seq)
667 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
669 tc->snd_wnd = snd_wnd;
672 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
674 /* Set probe timer if we just got 0 wnd */
675 if (tc->snd_wnd < tc->snd_mss
676 && !tcp_timer_is_active (tc, TCP_TIMER_PERSIST))
677 tcp_persist_timer_set (tc);
679 tcp_persist_timer_reset (tc);
684 tcp_cc_congestion (tcp_connection_t * tc)
686 tc->snd_congestion = tc->snd_nxt;
687 tc->cc_algo->congestion (tc);
688 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
692 tcp_cc_recover (tcp_connection_t * tc)
694 /* TODO: check if time to recover was small. It might be that RTO popped
698 tc->cc_algo->recovered (tc);
702 tc->snd_nxt = tc->snd_una;
704 tc->cc_algo->rcv_ack (tc);
705 tc->tsecr_last_ack = tc->opt.tsecr;
707 tcp_cong_recovery_off (tc);
709 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
713 tcp_cc_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b)
717 if (tcp_in_cong_recovery (tc))
719 partial_ack = seq_lt (tc->snd_una, tc->snd_congestion);
722 /* Clear retransmitted bytes. */
727 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
729 /* Clear retransmitted bytes. XXX should we clear all? */
731 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
733 /* In case snd_nxt is still in the past and output tries to
734 * shove some new bytes */
735 tc->snd_nxt = tc->snd_una_max;
737 /* XXX need proper RFC6675 support */
738 if (tc->sack_sb.last_sacked_bytes && !tcp_in_recovery (tc))
740 tcp_fast_retransmit (tc);
744 /* Retransmit first unacked segment */
745 tcp_retransmit_first_unacked (tc);
751 tc->cc_algo->rcv_ack (tc);
752 tc->tsecr_last_ack = tc->opt.tsecr;
758 tcp_cc_rcv_dupack (tcp_connection_t * tc, u32 ack)
760 // ASSERT (seq_geq(tc->snd_una, ack));
763 if (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
765 /* RFC6582 NewReno heuristic to avoid multiple fast retransmits */
766 if (tc->opt.tsecr != tc->tsecr_last_ack)
772 tcp_fastrecovery_on (tc);
774 /* Handle congestion and dupack */
775 tcp_cc_congestion (tc);
776 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
778 tcp_fast_retransmit (tc);
780 /* Post retransmit update cwnd to ssthresh and account for the
781 * three segments that have left the network and should've been
782 * buffered at the receiver */
783 tc->cwnd = tc->ssthresh + TCP_DUPACK_THRESHOLD * tc->snd_mss;
785 else if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD)
787 ASSERT (tcp_in_fastrecovery (tc));
789 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
794 tcp_cc_init (tcp_connection_t * tc)
796 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
797 tc->cc_algo->init (tc);
801 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
802 tcp_header_t * th, u32 * next, u32 * error)
806 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
807 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt))
809 /* If we have outstanding data and this is within the window, accept it,
810 * probably retransmit has timed out. Otherwise ACK segment and then
812 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
814 tcp_make_ack (tc, b);
815 *next = tcp_next_output (tc->c_is_ip4);
816 *error = TCP_ERROR_ACK_INVALID;
817 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
818 vnet_buffer (b)->tcp.ack_number);
822 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
823 vnet_buffer (b)->tcp.ack_number);
825 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
826 *error = TCP_ERROR_ACK_FUTURE;
829 /* If old ACK, probably it's an old dupack */
830 if (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
832 *error = TCP_ERROR_ACK_OLD;
833 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
834 vnet_buffer (b)->tcp.ack_number);
835 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
837 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
838 tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number);
843 if (tcp_opts_sack_permitted (&tc->opt))
844 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
846 new_snd_wnd = clib_net_to_host_u16 (th->window) << tc->snd_wscale;
848 if (tcp_ack_is_dupack (tc, b, new_snd_wnd))
850 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
851 tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number);
852 *error = TCP_ERROR_ACK_DUP;
860 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
861 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
863 /* Dequeue ACKed data and update RTT */
864 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
865 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
866 vnet_buffer (b)->tcp.ack_number, new_snd_wnd);
868 /* If some of our sent bytes have been acked, update cc and retransmit
872 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
874 /* Updates congestion control (slow start/congestion avoidance) */
875 tcp_cc_rcv_ack (tc, b);
877 /* If everything has been acked, stop retransmit timer
878 * otherwise update */
879 if (tc->snd_una == tc->snd_una_max)
880 tcp_retransmit_timer_reset (tc);
882 tcp_retransmit_timer_update (tc);
889 * Build SACK list as per RFC2018.
891 * Makes sure the first block contains the segment that generated the current
892 * ACK and the following ones are the ones most recently reported in SACK
895 * @param tc TCP connection for which the SACK list is updated
896 * @param start Start sequence number of the newest SACK block
897 * @param end End sequence of the newest SACK block
900 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
902 sack_block_t *new_list = 0, block;
905 /* If the first segment is ooo add it to the list. Last write might've moved
906 * rcv_nxt over the first segment. */
907 if (seq_lt (tc->rcv_nxt, start))
911 vec_add1 (new_list, block);
914 /* Find the blocks still worth keeping. */
915 for (i = 0; i < vec_len (tc->snd_sacks); i++)
918 * 1) rcv_nxt advanced beyond current block OR
919 * 2) Segment overlapped by the first segment, i.e., it has been merged
921 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt)
922 || seq_leq (tc->snd_sacks[i].start, end))
925 /* Save to new SACK list. */
926 vec_add1 (new_list, tc->snd_sacks[i]);
929 ASSERT (vec_len (new_list) < TCP_MAX_SACK_BLOCKS);
931 /* Replace old vector with new one */
932 vec_free (tc->snd_sacks);
933 tc->snd_sacks = new_list;
936 /** Enqueue data for delivery to application */
938 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
943 /* Pure ACK. Update rcv_nxt and be done. */
944 if (PREDICT_FALSE (data_len == 0))
946 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
947 return TCP_ERROR_PURE_ACK;
950 written = stream_session_enqueue_data (&tc->connection,
951 vlib_buffer_get_current (b),
952 data_len, 1 /* queue event */ );
954 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
957 if (PREDICT_TRUE (written == data_len))
959 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
961 /* If more data written than expected, account for out-of-order bytes. */
962 else if (written > data_len)
964 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end + written - data_len;
966 /* Send ACK confirming the update */
967 tc->flags |= TCP_CONN_SNDACK;
969 else if (written > 0)
971 /* We've written something but FIFO is probably full now */
972 tc->rcv_nxt += written;
974 /* Depending on how fast the app is, all remaining buffers in burst will
975 * not be enqueued. Inform peer */
976 tc->flags |= TCP_CONN_SNDACK;
978 return TCP_ERROR_PARTIALLY_ENQUEUED;
982 tc->flags |= TCP_CONN_SNDACK;
983 return TCP_ERROR_FIFO_FULL;
986 /* Update SACK list if need be */
987 if (tcp_opts_sack_permitted (&tc->opt))
989 /* Remove SACK blocks that have been delivered */
990 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
993 return TCP_ERROR_ENQUEUED;
996 /** Enqueue out-of-order data */
998 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1001 stream_session_t *s0;
1005 /* Pure ACK. Do nothing */
1006 if (PREDICT_FALSE (data_len == 0))
1008 return TCP_ERROR_PURE_ACK;
1011 s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
1012 seq = vnet_buffer (b)->tcp.seq_number;
1013 offset = seq - tc->rcv_nxt;
1015 rv = svm_fifo_enqueue_with_offset (s0->server_rx_fifo, s0->pid, offset,
1016 data_len, vlib_buffer_get_current (b));
1018 /* Nothing written */
1021 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1022 return TCP_ERROR_FIFO_FULL;
1025 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1027 /* Update SACK list if in use */
1028 if (tcp_opts_sack_permitted (&tc->opt))
1030 ooo_segment_t *newest;
1033 /* Get the newest segment from the fifo */
1034 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1035 start = tc->rcv_nxt + ooo_segment_offset (s0->server_rx_fifo, newest);
1036 end = tc->rcv_nxt + ooo_segment_end_offset (s0->server_rx_fifo, newest);
1038 tcp_update_sack_list (tc, start, end);
1041 return TCP_ERROR_ENQUEUED;
1045 * Check if ACK could be delayed. If ack can be delayed, it should return
1046 * true for a full frame. If we're always acking return 0.
1049 tcp_can_delack (tcp_connection_t * tc)
1051 /* Send ack if ... */
1053 /* just sent a rcv wnd 0 */
1054 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1055 /* constrained to send ack */
1056 || (tc->flags & TCP_CONN_SNDACK) != 0
1057 /* we're almost out of tx wnd */
1058 || tcp_available_snd_space (tc) < 2 * tc->snd_mss)
1065 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1066 u16 n_data_bytes, u32 * next0)
1070 /* Handle out-of-order data */
1071 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1073 /* Old sequence numbers allowed through because they overlapped
1075 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1077 error = TCP_ERROR_SEGMENT_OLD;
1078 *next0 = TCP_NEXT_DROP;
1082 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1084 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1085 * cwnd on remote peer when congested 2) acks leaving should have the
1086 * latest rcv_wnd since the burst may eaten up all of it, so only the
1087 * old ones could be filtered.
1090 /* RFC2581: Send DUPACK for fast retransmit */
1091 tcp_make_ack (tc, b);
1092 *next0 = tcp_next_output (tc->c_is_ip4);
1094 /* Mark as DUPACK. We may filter these in output if
1095 * the burst fills the holes. */
1097 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1099 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1103 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1104 * segments can be enqueued after fifo tail offset changes. */
1105 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1107 if (n_data_bytes == 0)
1109 *next0 = TCP_NEXT_DROP;
1113 /* Check if ACK can be delayed */
1114 if (tcp_can_delack (tc))
1116 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1117 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1121 *next0 = tcp_next_output (tc->c_is_ip4);
1122 tcp_make_ack (tc, b);
1130 tcp_header_t tcp_header;
1131 tcp_connection_t tcp_connection;
1135 format_tcp_rx_trace (u8 * s, va_list * args)
1137 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1138 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1139 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1140 uword indent = format_get_indent (s);
1142 s = format (s, "%U\n%U%U",
1143 format_tcp_header, &t->tcp_header, 128,
1144 format_white_space, indent,
1145 format_tcp_connection_verbose, &t->tcp_connection);
1151 format_tcp_rx_trace_short (u8 * s, va_list * args)
1153 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1154 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1155 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1157 s = format (s, "%d -> %d (%U)",
1158 clib_net_to_host_u16 (t->tcp_header.src_port),
1159 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1160 &t->tcp_connection.state);
1166 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1168 if (PREDICT_TRUE (!val))
1172 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1174 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1178 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1179 vlib_frame_t * from_frame, int is_ip4)
1181 u32 n_left_from, next_index, *from, *to_next;
1182 u32 my_thread_index = vm->thread_index, errors = 0;
1183 tcp_main_t *tm = vnet_get_tcp_main ();
1185 from = vlib_frame_vector_args (from_frame);
1186 n_left_from = from_frame->n_vectors;
1188 next_index = node->cached_next_index;
1190 while (n_left_from > 0)
1194 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1196 while (n_left_from > 0 && n_left_to_next > 0)
1201 tcp_header_t *th0 = 0;
1202 tcp_connection_t *tc0;
1205 u32 n_advance_bytes0, n_data_bytes0;
1206 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1213 n_left_to_next -= 1;
1215 b0 = vlib_get_buffer (vm, bi0);
1216 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1219 if (PREDICT_FALSE (tc0 == 0))
1221 error0 = TCP_ERROR_INVALID_CONNECTION;
1225 /* Checksum computed by ipx_local no need to compute again */
1229 ip40 = vlib_buffer_get_current (b0);
1230 th0 = ip4_next_header (ip40);
1231 n_advance_bytes0 = (ip4_header_bytes (ip40)
1232 + tcp_header_bytes (th0));
1233 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
1238 ip60 = vlib_buffer_get_current (b0);
1239 th0 = ip6_next_header (ip60);
1240 n_advance_bytes0 = tcp_header_bytes (th0);
1241 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
1243 n_advance_bytes0 += sizeof (ip60[0]);
1246 /* SYNs, FINs and data consume sequence numbers */
1247 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1248 + tcp_is_syn (th0) + tcp_is_fin (th0) + n_data_bytes0;
1250 /* TODO header prediction fast path */
1252 /* 1-4: check SEQ, RST, SYN */
1253 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1255 error0 = TCP_ERROR_SEGMENT_INVALID;
1256 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1257 vnet_buffer (b0)->tcp.seq_number,
1258 vnet_buffer (b0)->tcp.seq_end);
1262 /* 5: check the ACK field */
1263 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1268 /* 6: check the URG bit TODO */
1270 /* 7: process the segment text */
1272 vlib_buffer_advance (b0, n_advance_bytes0);
1273 error0 = tcp_segment_rcv (tm, tc0, b0, n_data_bytes0, &next0);
1275 /* 8: check the FIN bit */
1278 /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
1279 * wait for session to call close. To avoid lingering
1280 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1281 tc0->state = TCP_STATE_CLOSE_WAIT;
1282 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1283 stream_session_disconnect_notify (&tc0->connection);
1284 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1288 b0->error = node->errors[error0];
1289 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1291 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1292 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1293 clib_memcpy (&t0->tcp_connection, tc0,
1294 sizeof (t0->tcp_connection));
1297 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1298 n_left_to_next, bi0, next0);
1301 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1304 errors = session_manager_flush_enqueue_events (my_thread_index);
1305 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1307 return from_frame->n_vectors;
1311 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1312 vlib_frame_t * from_frame)
1314 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1318 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1319 vlib_frame_t * from_frame)
1321 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1325 VLIB_REGISTER_NODE (tcp4_established_node) =
1327 .function = tcp4_established,
1328 .name = "tcp4-established",
1329 /* Takes a vector of packets. */
1330 .vector_size = sizeof (u32),
1331 .n_errors = TCP_N_ERROR,
1332 .error_strings = tcp_error_strings,
1333 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1336 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1337 foreach_tcp_state_next
1340 .format_trace = format_tcp_rx_trace_short,
1344 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1347 VLIB_REGISTER_NODE (tcp6_established_node) =
1349 .function = tcp6_established,
1350 .name = "tcp6-established",
1351 /* Takes a vector of packets. */
1352 .vector_size = sizeof (u32),
1353 .n_errors = TCP_N_ERROR,
1354 .error_strings = tcp_error_strings,
1355 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1358 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1359 foreach_tcp_state_next
1362 .format_trace = format_tcp_rx_trace_short,
1367 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1369 vlib_node_registration_t tcp4_syn_sent_node;
1370 vlib_node_registration_t tcp6_syn_sent_node;
1373 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1374 vlib_frame_t * from_frame, int is_ip4)
1376 tcp_main_t *tm = vnet_get_tcp_main ();
1377 u32 n_left_from, next_index, *from, *to_next;
1378 u32 my_thread_index = vm->thread_index, errors = 0;
1379 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
1381 from = vlib_frame_vector_args (from_frame);
1382 n_left_from = from_frame->n_vectors;
1384 next_index = node->cached_next_index;
1386 while (n_left_from > 0)
1390 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1392 while (n_left_from > 0 && n_left_to_next > 0)
1394 u32 bi0, ack0, seq0;
1397 tcp_header_t *tcp0 = 0;
1398 tcp_connection_t *tc0;
1401 u32 n_advance_bytes0, n_data_bytes0;
1402 tcp_connection_t *new_tc0;
1403 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1410 n_left_to_next -= 1;
1412 b0 = vlib_get_buffer (vm, bi0);
1414 tcp_half_open_connection_get (vnet_buffer (b0)->
1415 tcp.connection_index);
1417 ack0 = vnet_buffer (b0)->tcp.ack_number;
1418 seq0 = vnet_buffer (b0)->tcp.seq_number;
1420 /* Checksum computed by ipx_local no need to compute again */
1424 ip40 = vlib_buffer_get_current (b0);
1425 tcp0 = ip4_next_header (ip40);
1426 n_advance_bytes0 = (ip4_header_bytes (ip40)
1427 + tcp_header_bytes (tcp0));
1428 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
1433 ip60 = vlib_buffer_get_current (b0);
1434 tcp0 = ip6_next_header (ip60);
1435 n_advance_bytes0 = tcp_header_bytes (tcp0);
1436 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
1438 n_advance_bytes0 += sizeof (ip60[0]);
1442 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1445 /* SYNs, FINs and data consume sequence numbers */
1446 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1447 + tcp_is_fin (tcp0) + n_data_bytes0;
1450 * 1. check the ACK bit
1454 * If the ACK bit is set
1455 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
1456 * the RST bit is set, if so drop the segment and return)
1457 * <SEQ=SEG.ACK><CTL=RST>
1458 * and discard the segment. Return.
1459 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
1463 if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt)
1465 if (!tcp_rst (tcp0))
1466 tcp_send_reset (b0, is_ip4);
1471 /* Make sure ACK is valid */
1472 if (tc0->snd_una > ack0)
1477 * 2. check the RST bit
1482 /* If ACK is acceptable, signal client that peer is not
1483 * willing to accept connection and drop connection*/
1486 stream_session_connect_notify (&tc0->connection, sst,
1488 tcp_connection_cleanup (tc0);
1494 * 3. check the security and precedence (skipped)
1498 * 4. check the SYN bit
1501 /* No SYN flag. Drop. */
1502 if (!tcp_syn (tcp0))
1505 /* Stop connection establishment and retransmit timers */
1506 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
1507 tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT_SYN);
1509 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
1510 * current thread pool. */
1511 pool_get (tm->connections[my_thread_index], new_tc0);
1512 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
1514 new_tc0->c_thread_index = my_thread_index;
1516 /* Cleanup half-open connection XXX lock */
1517 pool_put (tm->half_open_connections, tc0);
1519 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
1520 new_tc0->irs = seq0;
1523 tcp_options_parse (tcp0, &new_tc0->opt);
1525 if (tcp_opts_tstamp (&new_tc0->opt))
1527 new_tc0->tsval_recent = new_tc0->opt.tsval;
1528 new_tc0->tsval_recent_age = tcp_time_now ();
1531 if (tcp_opts_wscale (&new_tc0->opt))
1532 new_tc0->snd_wscale = new_tc0->opt.wscale;
1535 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
1536 new_tc0->snd_wl1 = seq0;
1537 new_tc0->snd_wl2 = ack0;
1539 tcp_connection_init_vars (new_tc0);
1541 /* SYN-ACK: See if we can switch to ESTABLISHED state */
1544 /* Our SYN is ACKed: we have iss < ack = snd_una */
1546 /* TODO Dequeue acknowledged segments if we support Fast Open */
1547 new_tc0->snd_una = ack0;
1548 new_tc0->state = TCP_STATE_ESTABLISHED;
1550 /* Make sure las is initialized for the wnd computation */
1551 new_tc0->rcv_las = new_tc0->rcv_nxt;
1553 /* Notify app that we have connection */
1554 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1556 /* Make sure after data segment processing ACK is sent */
1557 new_tc0->flags |= TCP_CONN_SNDACK;
1559 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
1562 new_tc0->state = TCP_STATE_SYN_RCVD;
1564 /* Notify app that we have connection */
1565 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1567 tcp_make_synack (new_tc0, b0);
1568 next0 = tcp_next_output (is_ip4);
1573 /* Read data, if any */
1577 tcp_segment_rcv (tm, new_tc0, b0, n_data_bytes0, &next0);
1578 if (error0 == TCP_ERROR_PURE_ACK)
1579 error0 = TCP_ERROR_SYN_ACKS_RCVD;
1583 tcp_make_ack (new_tc0, b0);
1584 next0 = tcp_next_output (new_tc0->c_is_ip4);
1589 b0->error = error0 ? node->errors[error0] : 0;
1590 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1592 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1593 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
1594 clib_memcpy (&t0->tcp_connection, tc0,
1595 sizeof (t0->tcp_connection));
1598 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1599 n_left_to_next, bi0, next0);
1602 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1605 errors = session_manager_flush_enqueue_events (my_thread_index);
1609 vlib_node_increment_counter (vm, tcp4_established_node.index,
1610 TCP_ERROR_EVENT_FIFO_FULL, errors);
1612 vlib_node_increment_counter (vm, tcp6_established_node.index,
1613 TCP_ERROR_EVENT_FIFO_FULL, errors);
1616 return from_frame->n_vectors;
1620 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
1621 vlib_frame_t * from_frame)
1623 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1627 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
1628 vlib_frame_t * from_frame)
1630 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1634 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
1636 .function = tcp4_syn_sent,
1637 .name = "tcp4-syn-sent",
1638 /* Takes a vector of packets. */
1639 .vector_size = sizeof (u32),
1640 .n_errors = TCP_N_ERROR,
1641 .error_strings = tcp_error_strings,
1642 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1645 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1646 foreach_tcp_state_next
1649 .format_trace = format_tcp_rx_trace_short,
1653 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
1656 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
1658 .function = tcp6_syn_sent_rcv,
1659 .name = "tcp6-syn-sent",
1660 /* Takes a vector of packets. */
1661 .vector_size = sizeof (u32),
1662 .n_errors = TCP_N_ERROR,
1663 .error_strings = tcp_error_strings,
1664 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1667 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1668 foreach_tcp_state_next
1671 .format_trace = format_tcp_rx_trace_short,
1675 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
1677 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
1678 * as per RFC793 p. 64
1681 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1682 vlib_frame_t * from_frame, int is_ip4)
1684 tcp_main_t *tm = vnet_get_tcp_main ();
1685 u32 n_left_from, next_index, *from, *to_next;
1686 u32 my_thread_index = vm->thread_index, errors = 0;
1688 from = vlib_frame_vector_args (from_frame);
1689 n_left_from = from_frame->n_vectors;
1691 next_index = node->cached_next_index;
1693 while (n_left_from > 0)
1697 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1699 while (n_left_from > 0 && n_left_to_next > 0)
1704 tcp_header_t *tcp0 = 0;
1705 tcp_connection_t *tc0;
1708 u32 n_advance_bytes0, n_data_bytes0;
1709 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1716 n_left_to_next -= 1;
1718 b0 = vlib_get_buffer (vm, bi0);
1719 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1721 if (PREDICT_FALSE (tc0 == 0))
1723 error0 = TCP_ERROR_INVALID_CONNECTION;
1727 /* Checksum computed by ipx_local no need to compute again */
1731 ip40 = vlib_buffer_get_current (b0);
1732 tcp0 = ip4_next_header (ip40);
1733 n_advance_bytes0 = (ip4_header_bytes (ip40)
1734 + tcp_header_bytes (tcp0));
1735 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
1740 ip60 = vlib_buffer_get_current (b0);
1741 tcp0 = ip6_next_header (ip60);
1742 n_advance_bytes0 = tcp_header_bytes (tcp0);
1743 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
1745 n_advance_bytes0 += sizeof (ip60[0]);
1748 /* SYNs, FINs and data consume sequence numbers */
1749 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1750 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0) + n_data_bytes0;
1753 * Special treatment for CLOSED
1757 case TCP_STATE_CLOSED:
1763 * For all other states (except LISTEN)
1766 /* 1-4: check SEQ, RST, SYN */
1768 (tcp_segment_validate (vm, tc0, b0, tcp0, &next0)))
1770 error0 = TCP_ERROR_SEGMENT_INVALID;
1774 /* 5: check the ACK field */
1777 case TCP_STATE_SYN_RCVD:
1779 * If the segment acknowledgment is not acceptable, form a
1781 * <SEQ=SEG.ACK><CTL=RST>
1784 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
1786 tcp_send_reset (b0, is_ip4);
1789 /* Switch state to ESTABLISHED */
1790 tc0->state = TCP_STATE_ESTABLISHED;
1792 /* Initialize session variables */
1793 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
1794 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
1796 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
1797 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
1799 /* Shoulder tap the server */
1800 stream_session_accept_notify (&tc0->connection);
1802 /* Reset SYN-ACK retransmit timer */
1803 tcp_retransmit_timer_reset (tc0);
1805 case TCP_STATE_ESTABLISHED:
1806 /* We can get packets in established state here because they
1807 * were enqueued before state change */
1808 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1812 case TCP_STATE_FIN_WAIT_1:
1813 /* In addition to the processing for the ESTABLISHED state, if
1814 * our FIN is now acknowledged then enter FIN-WAIT-2 and
1815 * continue processing in that state. */
1816 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1819 /* If FIN is ACKed */
1820 if (tc0->snd_una == tc0->snd_una_max)
1822 tc0->state = TCP_STATE_FIN_WAIT_2;
1823 /* Stop all timers, 2MSL will be set lower */
1824 tcp_connection_timers_reset (tc0);
1827 case TCP_STATE_FIN_WAIT_2:
1828 /* In addition to the processing for the ESTABLISHED state, if
1829 * the retransmission queue is empty, the user's CLOSE can be
1830 * acknowledged ("ok") but do not delete the TCB. */
1831 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1833 /* check if rtx queue is empty and ack CLOSE TODO */
1835 case TCP_STATE_CLOSE_WAIT:
1836 /* Do the same processing as for the ESTABLISHED state. */
1837 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1840 case TCP_STATE_CLOSING:
1841 /* In addition to the processing for the ESTABLISHED state, if
1842 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
1843 * otherwise ignore the segment. */
1844 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1847 /* XXX test that send queue empty */
1848 tc0->state = TCP_STATE_TIME_WAIT;
1852 case TCP_STATE_LAST_ACK:
1853 /* The only thing that can arrive in this state is an
1854 * acknowledgment of our FIN. If our FIN is now acknowledged,
1855 * delete the TCB, enter the CLOSED state, and return. */
1857 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
1860 tc0->state = TCP_STATE_CLOSED;
1862 /* Don't delete the connection/session yet. Instead, wait a
1863 * reasonable amount of time until the pipes are cleared. In
1864 * particular, this makes sure that we won't have dead sessions
1865 * when processing events on the tx path */
1866 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
1868 /* Stop retransmit */
1869 tcp_retransmit_timer_reset (tc0);
1874 case TCP_STATE_TIME_WAIT:
1875 /* The only thing that can arrive in this state is a
1876 * retransmission of the remote FIN. Acknowledge it, and restart
1877 * the 2 MSL timeout. */
1886 /* 6: check the URG bit TODO */
1888 /* 7: process the segment text */
1891 case TCP_STATE_ESTABLISHED:
1892 case TCP_STATE_FIN_WAIT_1:
1893 case TCP_STATE_FIN_WAIT_2:
1894 vlib_buffer_advance (b0, n_advance_bytes0);
1895 error0 = tcp_segment_rcv (tm, tc0, b0, n_data_bytes0, &next0);
1897 case TCP_STATE_CLOSE_WAIT:
1898 case TCP_STATE_CLOSING:
1899 case TCP_STATE_LAST_ACK:
1900 case TCP_STATE_TIME_WAIT:
1901 /* This should not occur, since a FIN has been received from the
1902 * remote side. Ignore the segment text. */
1906 /* 8: check the FIN bit */
1907 if (!tcp_fin (tcp0))
1912 case TCP_STATE_ESTABLISHED:
1913 case TCP_STATE_SYN_RCVD:
1914 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
1915 tcp_connection_timers_reset (tc0);
1916 tcp_make_fin (tc0, b0);
1917 next0 = tcp_next_output (tc0->c_is_ip4);
1918 stream_session_disconnect_notify (&tc0->connection);
1919 tc0->state = TCP_STATE_CLOSE_WAIT;
1921 case TCP_STATE_CLOSE_WAIT:
1922 case TCP_STATE_CLOSING:
1923 case TCP_STATE_LAST_ACK:
1926 case TCP_STATE_FIN_WAIT_1:
1927 tc0->state = TCP_STATE_TIME_WAIT;
1928 tcp_connection_timers_reset (tc0);
1929 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
1931 case TCP_STATE_FIN_WAIT_2:
1932 /* Got FIN, send ACK! */
1933 tc0->state = TCP_STATE_TIME_WAIT;
1934 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1935 tcp_make_ack (tc0, b0);
1936 next0 = tcp_next_output (is_ip4);
1938 case TCP_STATE_TIME_WAIT:
1939 /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
1942 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
1945 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1947 b0->error = error0 ? node->errors[error0] : 0;
1950 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1952 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1953 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
1954 clib_memcpy (&t0->tcp_connection, tc0,
1955 sizeof (t0->tcp_connection));
1958 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1959 n_left_to_next, bi0, next0);
1962 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1965 errors = session_manager_flush_enqueue_events (my_thread_index);
1969 vlib_node_increment_counter (vm, tcp4_established_node.index,
1970 TCP_ERROR_EVENT_FIFO_FULL, errors);
1972 vlib_node_increment_counter (vm, tcp6_established_node.index,
1973 TCP_ERROR_EVENT_FIFO_FULL, errors);
1976 return from_frame->n_vectors;
1980 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
1981 vlib_frame_t * from_frame)
1983 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1987 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
1988 vlib_frame_t * from_frame)
1990 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1994 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
1996 .function = tcp4_rcv_process,
1997 .name = "tcp4-rcv-process",
1998 /* Takes a vector of packets. */
1999 .vector_size = sizeof (u32),
2000 .n_errors = TCP_N_ERROR,
2001 .error_strings = tcp_error_strings,
2002 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2005 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2006 foreach_tcp_state_next
2009 .format_trace = format_tcp_rx_trace_short,
2013 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2016 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2018 .function = tcp6_rcv_process,
2019 .name = "tcp6-rcv-process",
2020 /* Takes a vector of packets. */
2021 .vector_size = sizeof (u32),
2022 .n_errors = TCP_N_ERROR,
2023 .error_strings = tcp_error_strings,
2024 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2027 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2028 foreach_tcp_state_next
2031 .format_trace = format_tcp_rx_trace_short,
2035 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2037 vlib_node_registration_t tcp4_listen_node;
2038 vlib_node_registration_t tcp6_listen_node;
2041 * LISTEN state processing as per RFC 793 p. 65
2044 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2045 vlib_frame_t * from_frame, int is_ip4)
2047 u32 n_left_from, next_index, *from, *to_next;
2048 u32 my_thread_index = vm->thread_index;
2049 tcp_main_t *tm = vnet_get_tcp_main ();
2050 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
2052 from = vlib_frame_vector_args (from_frame);
2053 n_left_from = from_frame->n_vectors;
2055 next_index = node->cached_next_index;
2057 while (n_left_from > 0)
2061 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2063 while (n_left_from > 0 && n_left_to_next > 0)
2068 tcp_header_t *th0 = 0;
2069 tcp_connection_t *lc0;
2072 tcp_connection_t *child0;
2073 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2080 n_left_to_next -= 1;
2082 b0 = vlib_get_buffer (vm, bi0);
2083 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2087 ip40 = vlib_buffer_get_current (b0);
2088 th0 = ip4_next_header (ip40);
2092 ip60 = vlib_buffer_get_current (b0);
2093 th0 = ip6_next_header (ip60);
2096 /* Create child session. For syn-flood protection use filter */
2098 /* 1. first check for an RST */
2102 /* 2. second check for an ACK */
2105 tcp_send_reset (b0, is_ip4);
2109 /* 3. check for a SYN (did that already) */
2111 /* Create child session and send SYN-ACK */
2112 pool_get (tm->connections[my_thread_index], child0);
2113 memset (child0, 0, sizeof (*child0));
2115 child0->c_c_index = child0 - tm->connections[my_thread_index];
2116 child0->c_lcl_port = lc0->c_lcl_port;
2117 child0->c_rmt_port = th0->src_port;
2118 child0->c_is_ip4 = is_ip4;
2119 child0->c_thread_index = my_thread_index;
2123 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2124 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2128 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2129 sizeof (ip6_address_t));
2130 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2131 sizeof (ip6_address_t));
2134 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2137 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2141 tcp_options_parse (th0, &child0->opt);
2143 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2144 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2145 child0->rcv_las = child0->rcv_nxt;
2146 child0->state = TCP_STATE_SYN_RCVD;
2148 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2149 * segments are used to initialize PAWS. */
2150 if (tcp_opts_tstamp (&child0->opt))
2152 child0->tsval_recent = child0->opt.tsval;
2153 child0->tsval_recent_age = tcp_time_now ();
2156 if (tcp_opts_wscale (&child0->opt))
2157 child0->snd_wscale = child0->opt.wscale;
2160 child0->snd_wnd = clib_net_to_host_u16 (th0->window);
2161 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2162 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2164 tcp_connection_init_vars (child0);
2166 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0);
2168 /* Reuse buffer to make syn-ack and send */
2169 tcp_make_synack (child0, b0);
2170 next0 = tcp_next_output (is_ip4);
2173 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2175 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2176 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2177 clib_memcpy (&t0->tcp_connection, lc0,
2178 sizeof (t0->tcp_connection));
2181 b0->error = node->errors[error0];
2183 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2184 n_left_to_next, bi0, next0);
2187 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2189 return from_frame->n_vectors;
2193 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2194 vlib_frame_t * from_frame)
2196 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2200 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2201 vlib_frame_t * from_frame)
2203 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2207 VLIB_REGISTER_NODE (tcp4_listen_node) =
2209 .function = tcp4_listen,
2210 .name = "tcp4-listen",
2211 /* Takes a vector of packets. */
2212 .vector_size = sizeof (u32),
2213 .n_errors = TCP_N_ERROR,
2214 .error_strings = tcp_error_strings,
2215 .n_next_nodes = TCP_LISTEN_N_NEXT,
2218 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2219 foreach_tcp_state_next
2222 .format_trace = format_tcp_rx_trace_short,
2226 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2229 VLIB_REGISTER_NODE (tcp6_listen_node) =
2231 .function = tcp6_listen,
2232 .name = "tcp6-listen",
2233 /* Takes a vector of packets. */
2234 .vector_size = sizeof (u32),
2235 .n_errors = TCP_N_ERROR,
2236 .error_strings = tcp_error_strings,
2237 .n_next_nodes = TCP_LISTEN_N_NEXT,
2240 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2241 foreach_tcp_state_next
2244 .format_trace = format_tcp_rx_trace_short,
2248 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2250 vlib_node_registration_t tcp4_input_node;
2251 vlib_node_registration_t tcp6_input_node;
2253 typedef enum _tcp_input_next
2255 TCP_INPUT_NEXT_DROP,
2256 TCP_INPUT_NEXT_LISTEN,
2257 TCP_INPUT_NEXT_RCV_PROCESS,
2258 TCP_INPUT_NEXT_SYN_SENT,
2259 TCP_INPUT_NEXT_ESTABLISHED,
2260 TCP_INPUT_NEXT_RESET,
2264 #define foreach_tcp4_input_next \
2265 _ (DROP, "error-drop") \
2266 _ (LISTEN, "tcp4-listen") \
2267 _ (RCV_PROCESS, "tcp4-rcv-process") \
2268 _ (SYN_SENT, "tcp4-syn-sent") \
2269 _ (ESTABLISHED, "tcp4-established") \
2270 _ (RESET, "tcp4-reset")
2272 #define foreach_tcp6_input_next \
2273 _ (DROP, "error-drop") \
2274 _ (LISTEN, "tcp6-listen") \
2275 _ (RCV_PROCESS, "tcp6-rcv-process") \
2276 _ (SYN_SENT, "tcp6-syn-sent") \
2277 _ (ESTABLISHED, "tcp6-established") \
2278 _ (RESET, "tcp6-reset")
2280 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2283 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2284 vlib_frame_t * from_frame, int is_ip4)
2286 u32 n_left_from, next_index, *from, *to_next;
2287 u32 my_thread_index = vm->thread_index;
2288 tcp_main_t *tm = vnet_get_tcp_main ();
2290 from = vlib_frame_vector_args (from_frame);
2291 n_left_from = from_frame->n_vectors;
2293 next_index = node->cached_next_index;
2295 while (n_left_from > 0)
2299 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2301 while (n_left_from > 0 && n_left_to_next > 0)
2306 tcp_header_t *tcp0 = 0;
2307 tcp_connection_t *tc0;
2310 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2318 n_left_to_next -= 1;
2320 b0 = vlib_get_buffer (vm, bi0);
2321 vnet_buffer (b0)->tcp.flags = 0;
2325 ip40 = vlib_buffer_get_current (b0);
2326 tcp0 = ip4_next_header (ip40);
2328 /* lookup session */
2330 (tcp_connection_t *)
2331 stream_session_lookup_transport4 (&ip40->dst_address,
2335 SESSION_TYPE_IP4_TCP,
2340 ip60 = vlib_buffer_get_current (b0);
2341 tcp0 = ip6_next_header (ip60);
2343 (tcp_connection_t *)
2344 stream_session_lookup_transport6 (&ip60->src_address,
2348 SESSION_TYPE_IP6_TCP,
2352 /* Session exists */
2353 if (PREDICT_TRUE (0 != tc0))
2355 /* Save connection index */
2356 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2357 vnet_buffer (b0)->tcp.seq_number =
2358 clib_net_to_host_u32 (tcp0->seq_number);
2359 vnet_buffer (b0)->tcp.ack_number =
2360 clib_net_to_host_u32 (tcp0->ack_number);
2362 flags0 = tcp0->flags & filter_flags;
2363 next0 = tm->dispatch_table[tc0->state][flags0].next;
2364 error0 = tm->dispatch_table[tc0->state][flags0].error;
2366 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH))
2368 /* Overload tcp flags to store state */
2369 vnet_buffer (b0)->tcp.flags = tc0->state;
2375 next0 = TCP_INPUT_NEXT_RESET;
2376 error0 = TCP_ERROR_NO_LISTENER;
2379 b0->error = error0 ? node->errors[error0] : 0;
2381 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2383 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2384 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2385 clib_memcpy (&t0->tcp_connection, tc0,
2386 sizeof (t0->tcp_connection));
2389 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2390 n_left_to_next, bi0, next0);
2393 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2396 return from_frame->n_vectors;
2400 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2401 vlib_frame_t * from_frame)
2403 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2407 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2408 vlib_frame_t * from_frame)
2410 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2414 VLIB_REGISTER_NODE (tcp4_input_node) =
2416 .function = tcp4_input,
2417 .name = "tcp4-input",
2418 /* Takes a vector of packets. */
2419 .vector_size = sizeof (u32),
2420 .n_errors = TCP_N_ERROR,
2421 .error_strings = tcp_error_strings,
2422 .n_next_nodes = TCP_INPUT_N_NEXT,
2425 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2426 foreach_tcp4_input_next
2429 .format_buffer = format_tcp_header,
2430 .format_trace = format_tcp_rx_trace,
2434 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
2437 VLIB_REGISTER_NODE (tcp6_input_node) =
2439 .function = tcp6_input,
2440 .name = "tcp6-input",
2441 /* Takes a vector of packets. */
2442 .vector_size = sizeof (u32),
2443 .n_errors = TCP_N_ERROR,
2444 .error_strings = tcp_error_strings,
2445 .n_next_nodes = TCP_INPUT_N_NEXT,
2448 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2449 foreach_tcp6_input_next
2452 .format_buffer = format_tcp_header,
2453 .format_trace = format_tcp_rx_trace,
2457 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
2460 tcp_dispatch_table_init (tcp_main_t * tm)
2463 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
2464 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
2466 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
2467 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
2470 #define _(t,f,n,e) \
2472 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
2473 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
2476 /* SYNs for new connections -> tcp-listen. */
2477 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
2478 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
2479 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2480 /* SYN-ACK for a SYN */
2481 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2483 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2484 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2485 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2487 /* ACK for for established connection -> tcp-established. */
2488 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2489 /* FIN for for established connection -> tcp-established. */
2490 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2491 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2493 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2494 /* ACK or FIN-ACK to our FIN */
2495 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2496 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
2498 /* FIN in reply to our FIN from the other side */
2499 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2500 /* FIN confirming that the peer (app) has closed */
2501 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2502 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2504 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2509 tcp_input_init (vlib_main_t * vm)
2511 clib_error_t *error = 0;
2512 tcp_main_t *tm = vnet_get_tcp_main ();
2514 if ((error = vlib_call_init_function (vm, tcp_init)))
2517 /* Initialize dispatch table. */
2518 tcp_dispatch_table_init (tm);
2523 VLIB_INIT_FUNCTION (tcp_input_init);
2526 * fd.io coding-style-patch-verification: ON
2529 * eval: (c-set-style "gnu")