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 _ (DROP4, "ip4-drop") \
31 _ (DROP6, "ip6-drop") \
32 _ (TCP4_OUTPUT, "tcp4-output") \
33 _ (TCP6_OUTPUT, "tcp6-output")
35 typedef enum _tcp_established_next
37 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
38 foreach_tcp_state_next
40 TCP_ESTABLISHED_N_NEXT,
41 } tcp_established_next_t;
43 typedef enum _tcp_rcv_process_next
45 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
46 foreach_tcp_state_next
48 TCP_RCV_PROCESS_N_NEXT,
49 } tcp_rcv_process_next_t;
51 typedef enum _tcp_syn_sent_next
53 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
54 foreach_tcp_state_next
57 } tcp_syn_sent_next_t;
59 typedef enum _tcp_listen_next
61 #define _(s,n) TCP_LISTEN_NEXT_##s,
62 foreach_tcp_state_next
67 /* Generic, state independent indices */
68 typedef enum _tcp_state_next
70 #define _(s,n) TCP_NEXT_##s,
71 foreach_tcp_state_next
76 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
77 : TCP_NEXT_TCP6_OUTPUT)
79 #define tcp_next_drop(is_ip4) (is_ip4 ? TCP_NEXT_DROP4 \
82 vlib_node_registration_t tcp4_established_node;
83 vlib_node_registration_t tcp6_established_node;
86 * Validate segment sequence number. As per RFC793:
88 * Segment Receive Test
90 * ------- ------- -------------------------------------------
91 * 0 0 SEG.SEQ = RCV.NXT
92 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
94 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
95 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
97 * This ultimately consists in checking if segment falls within the window.
98 * The one important difference compared to RFC793 is that we use rcv_las,
99 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
100 * peer's reference when computing our receive window.
103 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
104 * however, is too strict when we have retransmits. Instead we just check that
105 * the seq is not beyond the right edge and that the end of the segment is not
106 * less than the left edge.
108 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
109 * use rcv_nxt in the right edge window test instead of rcv_las.
113 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
115 return (seq_geq (end_seq, tc->rcv_las)
116 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
120 * Parse TCP header options.
122 * @param th TCP header
123 * @param to TCP options data structure to be populated
124 * @return -1 if parsing failed
127 tcp_options_parse (tcp_header_t * th, tcp_options_t * to)
130 u8 opt_len, opts_len, kind;
134 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
135 data = (const u8 *) (th + 1);
137 /* Zero out all flags but those set in SYN */
138 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE);
140 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
144 /* Get options length */
145 if (kind == TCP_OPTION_EOL)
147 else if (kind == TCP_OPTION_NOOP)
159 /* weird option length */
160 if (opt_len < 2 || opt_len > opts_len)
168 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
170 to->flags |= TCP_OPTS_FLAG_MSS;
171 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
174 case TCP_OPTION_WINDOW_SCALE:
175 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
177 to->flags |= TCP_OPTS_FLAG_WSCALE;
178 to->wscale = data[2];
179 if (to->wscale > TCP_MAX_WND_SCALE)
181 clib_warning ("Illegal window scaling value: %d",
183 to->wscale = TCP_MAX_WND_SCALE;
187 case TCP_OPTION_TIMESTAMP:
188 if (opt_len == TCP_OPTION_LEN_TIMESTAMP)
190 to->flags |= TCP_OPTS_FLAG_TSTAMP;
191 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
192 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
195 case TCP_OPTION_SACK_PERMITTED:
196 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
197 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
199 case TCP_OPTION_SACK_BLOCK:
200 /* If SACK permitted was not advertised or a SYN, break */
201 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
204 /* If too short or not correctly formatted, break */
205 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
208 to->flags |= TCP_OPTS_FLAG_SACK;
209 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
210 vec_reset_length (to->sacks);
211 for (j = 0; j < to->n_sack_blocks; j++)
213 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
214 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
215 vec_add1 (to->sacks, b);
219 /* Nothing to see here */
227 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
228 * timestamp to echo and it's less than tsval_recent, drop segment
229 * but still send an ACK in order to retain TCP's mechanism for detecting
230 * and recovering from half-open connections
232 * Or at least that's what the theory says. It seems that this might not work
233 * very well with packet reordering and fast retransmit. XXX
236 tcp_segment_check_paws (tcp_connection_t * tc)
238 return tcp_opts_tstamp (&tc->rcv_opts) && tc->tsval_recent
239 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
243 * Update tsval recent
246 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
249 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
250 * of an incoming segment:
251 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
252 * then the TSval from the segment is copied to TS.Recent;
253 * otherwise, the TSval is ignored.
255 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
256 && seq_leq (tc->rcv_las, seq_end))
258 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
259 tc->tsval_recent = tc->rcv_opts.tsval;
260 tc->tsval_recent_age = tcp_time_now ();
265 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
267 * It first verifies if segment has a wrapped sequence number (PAWS) and then
268 * does the processing associated to the first four steps (ignoring security
269 * and precedence): sequence number, rst bit and syn bit checks.
271 * @return 0 if segments passes validation.
274 tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0,
275 vlib_buffer_t * b0, tcp_header_t * th0,
276 u32 * next0, u32 * error0)
278 /* We could get a burst of RSTs interleaved with acks */
279 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
281 tcp_send_reset (tc0);
282 *error0 = TCP_ERROR_CONNECTION_CLOSED;
286 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
288 *error0 = TCP_ERROR_SEGMENT_INVALID;
292 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts)))
294 clib_warning ("options parse error");
295 *error0 = TCP_ERROR_OPTIONS;
299 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
301 *error0 = TCP_ERROR_PAWS;
303 clib_warning ("paws failed\n%U", format_tcp_connection, tc0, 2);
304 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
305 vnet_buffer (b0)->tcp.seq_end);
307 /* If it just so happens that a segment updates tsval_recent for a
308 * segment over 24 days old, invalidate tsval_recent. */
309 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
312 /* Age isn't reset until we get a valid tsval (bsd inspired) */
313 tc0->tsval_recent = 0;
314 clib_warning ("paws failed - really old segment. REALLY?");
318 /* Drop after ack if not rst */
321 tcp_make_ack (tc0, b0);
322 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
329 /* 1st: check sequence number */
330 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
331 vnet_buffer (b0)->tcp.seq_end))
333 *error0 = TCP_ERROR_RCV_WND;
334 /* If our window is 0 and the packet is in sequence, let it pass
335 * through for ack processing. It should be dropped later. */
336 if (!(tc0->rcv_wnd == 0
337 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number))
339 /* If not RST, send dup ack */
342 tcp_make_ack (tc0, b0);
343 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
350 /* 2nd: check the RST bit */
351 if (PREDICT_FALSE (tcp_rst (th0)))
353 tcp_connection_reset (tc0);
354 *error0 = TCP_ERROR_RST_RCVD;
358 /* 3rd: check security and precedence (skip) */
360 /* 4th: check the SYN bit */
361 if (PREDICT_FALSE (tcp_syn (th0)))
363 /* TODO implement RFC 5961 */
364 if (tc0->state == TCP_STATE_SYN_RCVD)
366 tcp_make_synack (tc0, b0);
367 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
371 tcp_make_ack (tc0, b0);
372 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
377 /* If segment in window, save timestamp */
378 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
379 vnet_buffer (b0)->tcp.seq_end);
383 *next0 = tcp_next_drop (tc0->c_is_ip4);
386 *next0 = tcp_next_output (tc0->c_is_ip4);
391 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
393 /* SND.UNA =< SEG.ACK =< SND.NXT */
394 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
395 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
399 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
401 * Note that although the original article, srtt and rttvar are scaled
402 * to minimize round-off errors, here we don't. Instead, we rely on
403 * better precision time measurements.
405 * TODO support us rtt resolution
408 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
414 err = mrtt - tc->srtt;
416 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
417 * The increase should be bound */
418 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
419 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
420 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
424 /* First measurement. */
426 tc->rttvar = mrtt >> 1;
431 tcp_update_rto (tcp_connection_t * tc)
433 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
434 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
438 * Update RTT estimate and RTO timer
440 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
441 * timing. Middle boxes are known to fiddle with TCP options so we
442 * should give higher priority to ACK timing.
444 * This should be called only if previously sent bytes have been acked.
446 * return 1 if valid rtt 0 otherwise
449 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
453 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
454 * RTT because they're ambiguous. */
455 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
458 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
460 mrtt = tcp_time_now () - tc->rtt_ts;
462 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
463 * snd_una, i.e., the left side of the send window:
464 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
465 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
467 mrtt = tcp_time_now () - tc->rcv_opts.tsecr;
470 /* Ignore dubious measurements */
471 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
474 tcp_estimate_rtt (tc, mrtt);
478 /* Allow measuring of a new RTT */
481 /* If we got here something must've been ACKed so make sure boff is 0,
482 * even if mrrt is not valid since we update the rto lower */
490 * Dequeue bytes that have been acked and while at it update RTT estimates.
493 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
495 /* Dequeue the newly ACKed add SACKed bytes */
496 stream_session_dequeue_drop (&tc->connection,
497 tc->bytes_acked + tc->sack_sb.snd_una_adv);
499 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
501 /* Update rtt and rto */
502 tcp_update_rtt (tc, ack);
504 /* If everything has been acked, stop retransmit timer
505 * otherwise update. */
506 tcp_retransmit_timer_update (tc);
510 * Check if duplicate ack as per RFC5681 Sec. 2
513 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
516 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
517 && seq_gt (tc->snd_una_max, tc->snd_una)
518 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
519 && (prev_snd_wnd == tc->snd_wnd));
523 * Checks if ack is a congestion control event.
526 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
527 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
529 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
530 * defined to be 'duplicate' */
531 *is_dack = tc->sack_sb.last_sacked_bytes
532 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
534 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
538 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
540 sack_scoreboard_hole_t *next, *prev;
542 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
544 next = pool_elt_at_index (sb->holes, hole->next);
545 next->prev = hole->prev;
549 sb->tail = hole->prev;
552 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
554 prev = pool_elt_at_index (sb->holes, hole->prev);
555 prev->next = hole->next;
559 sb->head = hole->next;
562 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
563 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
565 /* Poison the entry */
567 memset (hole, 0xfe, sizeof (*hole));
569 pool_put (sb->holes, hole);
572 sack_scoreboard_hole_t *
573 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
576 sack_scoreboard_hole_t *hole, *next, *prev;
579 pool_get (sb->holes, hole);
580 memset (hole, 0, sizeof (*hole));
584 hole_index = scoreboard_hole_index (sb, hole);
586 prev = scoreboard_get_hole (sb, prev_index);
589 hole->prev = prev_index;
590 hole->next = prev->next;
592 if ((next = scoreboard_next_hole (sb, hole)))
593 next->prev = hole_index;
595 sb->tail = hole_index;
597 prev->next = hole_index;
601 sb->head = hole_index;
602 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
603 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
610 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
612 sack_scoreboard_hole_t *hole, *prev;
613 u32 bytes = 0, blks = 0;
616 sb->sacked_bytes = 0;
617 hole = scoreboard_last_hole (sb);
621 if (seq_gt (sb->high_sacked, hole->end))
623 bytes = sb->high_sacked - hole->end;
627 while ((prev = scoreboard_prev_hole (sb, hole))
628 && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
629 && blks < TCP_DUPACK_THRESHOLD))
631 bytes += hole->start - prev->end;
638 sb->lost_bytes += scoreboard_hole_bytes (hole);
641 hole = scoreboard_prev_hole (sb, hole);
643 bytes += prev->start - hole->end;
645 sb->sacked_bytes = bytes;
649 * Figure out the next hole to retransmit
651 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
653 sack_scoreboard_hole_t *
654 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
655 sack_scoreboard_hole_t * start,
657 u8 * can_rescue, u8 * snd_limited)
659 sack_scoreboard_hole_t *hole = 0;
661 hole = start ? start : scoreboard_first_hole (sb);
662 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
663 hole = scoreboard_next_hole (sb, hole);
665 /* Nothing, return */
668 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
672 /* Rule (1): if higher than rxt, less than high_sacked and lost */
673 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
675 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
679 /* Rule (2): output takes care of transmitting new data */
680 if (!have_sent_1_smss)
683 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
685 /* Rule (3): if hole not lost */
686 else if (seq_lt (hole->start, sb->high_sacked))
689 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
691 /* Rule (4): if hole beyond high_sacked */
694 ASSERT (seq_geq (hole->start, sb->high_sacked));
697 /* HighRxt MUST NOT be updated */
702 if (hole && seq_lt (sb->high_rxt, hole->start))
703 sb->high_rxt = hole->start;
709 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
711 sack_scoreboard_hole_t *hole;
712 hole = scoreboard_first_hole (sb);
715 seq = seq_gt (seq, hole->start) ? seq : hole->start;
716 sb->cur_rxt_hole = sb->head;
722 * Test that scoreboard is sane after recovery
724 * Returns 1 if scoreboard is empty or if first hole beyond
728 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
730 sack_scoreboard_hole_t *hole;
731 hole = scoreboard_first_hole (&tc->sack_sb);
732 return (!hole || seq_geq (hole->start, tc->snd_una));
736 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
738 sack_scoreboard_t *sb = &tc->sack_sb;
739 sack_block_t *blk, tmp;
740 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
741 u32 blk_index = 0, old_sacked_bytes, hole_index;
744 sb->last_sacked_bytes = 0;
746 old_sacked_bytes = sb->sacked_bytes;
747 sb->last_bytes_delivered = 0;
749 if (!tcp_opts_sack (&tc->rcv_opts)
750 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
753 /* Remove invalid blocks */
754 blk = tc->rcv_opts.sacks;
755 while (blk < vec_end (tc->rcv_opts.sacks))
757 if (seq_lt (blk->start, blk->end)
758 && seq_gt (blk->start, tc->snd_una)
759 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
764 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
767 /* Add block for cumulative ack */
768 if (seq_gt (ack, tc->snd_una))
770 tmp.start = tc->snd_una;
772 vec_add1 (tc->rcv_opts.sacks, tmp);
775 if (vec_len (tc->rcv_opts.sacks) == 0)
778 tcp_scoreboard_trace_add (tc, ack);
780 /* Make sure blocks are ordered */
781 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
782 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
783 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
785 tmp = tc->rcv_opts.sacks[i];
786 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
787 tc->rcv_opts.sacks[j] = tmp;
790 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
792 /* If no holes, insert the first that covers all outstanding bytes */
793 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
794 tc->snd_una, tc->snd_una_max);
795 sb->tail = scoreboard_hole_index (sb, last_hole);
796 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
797 sb->high_sacked = tmp.end;
801 /* If we have holes but snd_una_max is beyond the last hole, update
803 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
804 last_hole = scoreboard_last_hole (sb);
805 if (seq_gt (tc->snd_una_max, last_hole->end))
807 if (seq_geq (last_hole->start, sb->high_sacked))
809 last_hole->end = tc->snd_una_max;
811 /* New hole after high sacked block */
812 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
814 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
818 /* Keep track of max byte sacked for when the last hole
820 if (seq_gt (tmp.end, sb->high_sacked))
821 sb->high_sacked = tmp.end;
824 /* Walk the holes with the SACK blocks */
825 hole = pool_elt_at_index (sb->holes, sb->head);
826 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
828 blk = &tc->rcv_opts.sacks[blk_index];
829 if (seq_leq (blk->start, hole->start))
831 /* Block covers hole. Remove hole */
832 if (seq_geq (blk->end, hole->end))
834 next_hole = scoreboard_next_hole (sb, hole);
836 /* Byte accounting: snd_una needs to be advanced */
841 if (seq_lt (ack, next_hole->start))
842 sb->snd_una_adv = next_hole->start - ack;
843 sb->last_bytes_delivered +=
844 next_hole->start - hole->end;
848 ASSERT (seq_geq (sb->high_sacked, ack));
849 sb->snd_una_adv = sb->high_sacked - ack;
850 sb->last_bytes_delivered += sb->high_sacked - hole->end;
854 scoreboard_remove_hole (sb, hole);
857 /* Partial 'head' overlap */
860 if (seq_gt (blk->end, hole->start))
862 hole->start = blk->end;
869 /* Hole must be split */
870 if (seq_lt (blk->end, hole->end))
872 hole_index = scoreboard_hole_index (sb, hole);
873 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
876 /* Pool might've moved */
877 hole = scoreboard_get_hole (sb, hole_index);
878 hole->end = blk->start;
880 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
882 else if (seq_lt (blk->start, hole->end))
884 hole->end = blk->start;
886 hole = scoreboard_next_hole (sb, hole);
890 scoreboard_update_bytes (tc, sb);
891 sb->last_sacked_bytes = sb->sacked_bytes
892 - (old_sacked_bytes - sb->last_bytes_delivered);
893 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
894 ASSERT (sb->sacked_bytes == 0
895 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
896 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
897 - seq_max (tc->snd_una, ack));
898 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
899 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
900 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
904 * Try to update snd_wnd based on feedback received from peer.
906 * If successful, and new window is 'effectively' 0, activate persist
910 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
912 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
913 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
914 if (seq_lt (tc->snd_wl1, seq)
915 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
917 tc->snd_wnd = snd_wnd;
920 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
922 if (tc->snd_wnd < tc->snd_mss)
924 /* Set persist timer if not set and we just got 0 wnd */
925 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
926 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
927 tcp_persist_timer_set (tc);
931 tcp_persist_timer_reset (tc);
932 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
942 * Init loss recovery/fast recovery.
944 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
945 * updated in @ref tcp_cc_handle_event after fast retransmit
948 tcp_cc_init_congestion (tcp_connection_t * tc)
950 tcp_fastrecovery_on (tc);
951 tc->snd_congestion = tc->snd_una_max;
952 tc->cwnd_acc_bytes = 0;
953 tc->cc_algo->congestion (tc);
954 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
958 tcp_cc_recovery_exit (tcp_connection_t * tc)
963 tc->snd_nxt = tc->snd_una_max;
964 tcp_recovery_off (tc);
965 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
969 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
971 tc->cc_algo->recovered (tc);
972 tc->snd_rxt_bytes = 0;
974 tc->snd_nxt = tc->snd_una_max;
975 tcp_fastrecovery_off (tc);
976 tcp_fastrecovery_1_smss_off (tc);
977 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
981 tcp_cc_congestion_undo (tcp_connection_t * tc)
983 tc->cwnd = tc->prev_cwnd;
984 tc->ssthresh = tc->prev_ssthresh;
985 tc->snd_nxt = tc->snd_una_max;
987 if (tcp_in_recovery (tc))
988 tcp_cc_recovery_exit (tc);
989 ASSERT (tc->rto_boff == 0);
990 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
991 /* TODO extend for fastrecovery */
995 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
997 return (tcp_in_recovery (tc) && tc->rto_boff == 1
999 && tcp_opts_tstamp (&tc->rcv_opts)
1000 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1004 tcp_cc_recover (tcp_connection_t * tc)
1006 ASSERT (tcp_in_cong_recovery (tc));
1007 if (tcp_cc_is_spurious_retransmit (tc))
1009 tcp_cc_congestion_undo (tc);
1013 if (tcp_in_recovery (tc))
1014 tcp_cc_recovery_exit (tc);
1015 else if (tcp_in_fastrecovery (tc))
1016 tcp_cc_fastrecovery_exit (tc);
1018 ASSERT (tc->rto_boff == 0);
1019 ASSERT (!tcp_in_cong_recovery (tc));
1020 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1025 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1027 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1029 /* Congestion avoidance */
1030 tc->cc_algo->rcv_ack (tc);
1031 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1033 /* If a cumulative ack, make sure dupacks is 0 */
1034 tc->rcv_dupacks = 0;
1036 /* When dupacks hits the threshold we only enter fast retransmit if
1037 * cumulative ack covers more than snd_congestion. Should snd_una
1038 * wrap this test may fail under otherwise valid circumstances.
1039 * Therefore, proactively update snd_congestion when wrap detected. */
1041 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1042 && seq_gt (tc->snd_congestion, tc->snd_una)))
1043 tc->snd_congestion = tc->snd_una - 1;
1047 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1049 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1053 tcp_should_fastrecover (tcp_connection_t * tc)
1055 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1056 || tcp_should_fastrecover_sack (tc));
1060 * One function to rule them all ... and in the darkness bind them
1063 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1067 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1069 if (tc->bytes_acked)
1071 tcp_fast_retransmit (tc);
1075 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1076 * it account for the bytes that left the network.
1078 else if (is_dack && !tcp_in_recovery (tc))
1080 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1081 ASSERT (tc->snd_una != tc->snd_una_max
1082 || tc->sack_sb.last_sacked_bytes);
1086 /* Pure duplicate ack. If some data got acked, it's handled lower */
1087 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1089 ASSERT (tcp_in_fastrecovery (tc));
1090 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1093 else if (tcp_should_fastrecover (tc))
1095 ASSERT (!tcp_in_fastrecovery (tc));
1097 /* If of of the two conditions lower hold, reset dupacks because
1098 * we're probably after timeout (RFC6582 heuristics).
1099 * If Cumulative ack does not cover more than congestion threshold,
1101 * 1) The following doesn't hold: The congestion window is greater
1102 * than SMSS bytes and the difference between highest_ack
1103 * and prev_highest_ack is at most 4*SMSS bytes
1104 * 2) Echoed timestamp in the last non-dup ack does not equal the
1107 if (seq_leq (tc->snd_una, tc->snd_congestion)
1108 && ((!(tc->cwnd > tc->snd_mss
1109 && tc->bytes_acked <= 4 * tc->snd_mss))
1110 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1112 tc->rcv_dupacks = 0;
1116 tcp_cc_init_congestion (tc);
1117 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1119 /* The first segment MUST be retransmitted */
1120 tcp_retransmit_first_unacked (tc);
1122 /* Post retransmit update cwnd to ssthresh and account for the
1123 * three segments that have left the network and should've been
1124 * buffered at the receiver XXX */
1125 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1126 ASSERT (tc->cwnd >= tc->snd_mss);
1128 /* If cwnd allows, send more data */
1129 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1131 scoreboard_init_high_rxt (&tc->sack_sb,
1132 tc->snd_una + tc->snd_mss);
1133 tcp_fast_retransmit_sack (tc);
1137 tcp_fast_retransmit_no_sack (tc);
1141 else if (!tc->bytes_acked
1142 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1144 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1151 if (!tc->bytes_acked)
1155 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1158 * Legitimate ACK. 1) See if we can exit recovery
1160 /* XXX limit this only to first partial ack? */
1161 tcp_retransmit_timer_update (tc);
1163 if (seq_geq (tc->snd_una, tc->snd_congestion))
1165 /* If spurious return, we've already updated everything */
1166 if (tcp_cc_recover (tc))
1168 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1172 tc->snd_nxt = tc->snd_una_max;
1174 /* Treat as congestion avoidance ack */
1175 tc->cc_algo->rcv_ack (tc);
1176 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1181 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1184 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1185 * reset dupacks to 0. Also needed if in congestion recovery */
1186 tc->rcv_dupacks = 0;
1188 /* Post RTO timeout don't try anything fancy */
1189 if (tcp_in_recovery (tc))
1191 tc->cc_algo->rcv_ack (tc);
1192 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1196 /* Remove retransmitted bytes that have been delivered */
1197 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1198 >= tc->sack_sb.last_bytes_delivered
1199 || (tc->flags & TCP_CONN_FINSNT));
1201 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1203 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1204 * remove sacked bytes delivered */
1205 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1206 - tc->sack_sb.last_bytes_delivered;
1207 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1208 tc->snd_rxt_bytes -= rxt_delivered;
1212 /* Either all retransmitted holes have been acked, or we're
1213 * "in the blind" and retransmitting segment by segment */
1214 tc->snd_rxt_bytes = 0;
1217 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1220 * Since this was a partial ack, try to retransmit some more data
1222 tcp_fast_retransmit (tc);
1226 tcp_cc_init (tcp_connection_t * tc)
1228 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
1229 tc->cc_algo->init (tc);
1233 * Process incoming ACK
1236 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1237 tcp_header_t * th, u32 * next, u32 * error)
1239 u32 prev_snd_wnd, prev_snd_una;
1242 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1244 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1245 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1247 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1248 * still has the data so accept the ack */
1249 if (tcp_in_recovery (tc)
1250 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion)
1251 && seq_geq (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1253 tc->snd_una_max = tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1257 /* If we have outstanding data and this is within the window, accept it,
1258 * probably retransmit has timed out. Otherwise ACK segment and then
1260 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1262 tcp_make_ack (tc, b);
1263 *next = tcp_next_output (tc->c_is_ip4);
1264 *error = TCP_ERROR_ACK_INVALID;
1265 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1266 vnet_buffer (b)->tcp.ack_number);
1270 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1271 vnet_buffer (b)->tcp.ack_number);
1273 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1274 *error = TCP_ERROR_ACK_FUTURE;
1277 /* If old ACK, probably it's an old dupack */
1278 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1280 *error = TCP_ERROR_ACK_OLD;
1281 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1282 vnet_buffer (b)->tcp.ack_number);
1283 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1284 tcp_cc_handle_event (tc, 1);
1285 /* Don't drop yet */
1290 * Looks okay, process feedback
1293 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1294 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1296 prev_snd_wnd = tc->snd_wnd;
1297 prev_snd_una = tc->snd_una;
1298 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1299 vnet_buffer (b)->tcp.ack_number,
1300 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1301 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1302 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1303 tcp_validate_txf_size (tc, tc->bytes_acked);
1305 if (tc->bytes_acked)
1306 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1308 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1311 * Check if we have congestion event
1314 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1316 tcp_cc_handle_event (tc, is_dack);
1317 if (!tcp_in_cong_recovery (tc))
1319 *error = TCP_ERROR_ACK_DUP;
1320 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1324 * Update congestion control (slow start/congestion avoidance)
1326 tcp_cc_update (tc, b);
1327 *error = TCP_ERROR_ACK_OK;
1332 tcp_sack_vector_is_sane (sack_block_t * sacks)
1335 for (i = 1; i < vec_len (sacks); i++)
1337 if (sacks[i - 1].end == sacks[i].start)
1344 * Build SACK list as per RFC2018.
1346 * Makes sure the first block contains the segment that generated the current
1347 * ACK and the following ones are the ones most recently reported in SACK
1350 * @param tc TCP connection for which the SACK list is updated
1351 * @param start Start sequence number of the newest SACK block
1352 * @param end End sequence of the newest SACK block
1355 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1357 sack_block_t *new_list = 0, *block = 0;
1360 /* If the first segment is ooo add it to the list. Last write might've moved
1361 * rcv_nxt over the first segment. */
1362 if (seq_lt (tc->rcv_nxt, start))
1364 vec_add2 (new_list, block, 1);
1365 block->start = start;
1369 /* Find the blocks still worth keeping. */
1370 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1372 /* Discard if rcv_nxt advanced beyond current block */
1373 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1376 /* Merge or drop if segment overlapped by the new segment */
1377 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1378 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1380 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1381 new_list[0].start = tc->snd_sacks[i].start;
1382 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1383 new_list[0].end = tc->snd_sacks[i].end;
1387 /* Save to new SACK list if we have space. */
1388 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1390 vec_add1 (new_list, tc->snd_sacks[i]);
1394 clib_warning ("sack discarded");
1398 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1400 /* Replace old vector with new one */
1401 vec_free (tc->snd_sacks);
1402 tc->snd_sacks = new_list;
1404 /* Segments should not 'touch' */
1405 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1409 tcp_sack_list_bytes (tcp_connection_t * tc)
1412 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1413 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1417 /** Enqueue data for delivery to application */
1419 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1422 int written, error = TCP_ERROR_ENQUEUED;
1424 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1426 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1427 1 /* queue event */ , 1);
1429 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1431 /* Update rcv_nxt */
1432 if (PREDICT_TRUE (written == data_len))
1434 tc->rcv_nxt += written;
1436 /* If more data written than expected, account for out-of-order bytes. */
1437 else if (written > data_len)
1439 tc->rcv_nxt += written;
1441 /* Send ACK confirming the update */
1442 tc->flags |= TCP_CONN_SNDACK;
1443 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1445 else if (written > 0)
1447 /* We've written something but FIFO is probably full now */
1448 tc->rcv_nxt += written;
1450 /* Depending on how fast the app is, all remaining buffers in burst will
1451 * not be enqueued. Inform peer */
1452 tc->flags |= TCP_CONN_SNDACK;
1454 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1458 tc->flags |= TCP_CONN_SNDACK;
1459 return TCP_ERROR_FIFO_FULL;
1462 /* Update SACK list if need be */
1463 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1465 /* Remove SACK blocks that have been delivered */
1466 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1472 /** Enqueue out-of-order data */
1474 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1477 stream_session_t *s0;
1480 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1483 /* Enqueue out-of-order data with relative offset */
1484 rv = session_enqueue_stream_connection (&tc->connection, b,
1485 vnet_buffer (b)->tcp.seq_number -
1486 tc->rcv_nxt, 0 /* queue event */ ,
1489 /* Nothing written */
1492 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1493 return TCP_ERROR_FIFO_FULL;
1496 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1498 /* Update SACK list if in use */
1499 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1501 ooo_segment_t *newest;
1504 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1506 /* Get the newest segment from the fifo */
1507 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1510 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1511 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1512 start = tc->rcv_nxt + offset;
1513 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1514 tcp_update_sack_list (tc, start, end);
1515 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1516 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1520 return TCP_ERROR_ENQUEUED_OOO;
1524 * Check if ACK could be delayed. If ack can be delayed, it should return
1525 * true for a full frame. If we're always acking return 0.
1528 tcp_can_delack (tcp_connection_t * tc)
1530 /* Send ack if ... */
1532 /* just sent a rcv wnd 0 */
1533 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1534 /* constrained to send ack */
1535 || (tc->flags & TCP_CONN_SNDACK) != 0
1536 /* we're almost out of tx wnd */
1537 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1544 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1546 u32 discard, first = b->current_length;
1547 vlib_main_t *vm = vlib_get_main ();
1549 /* Handle multi-buffer segments */
1550 if (n_bytes_to_drop > b->current_length)
1552 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1556 discard = clib_min (n_bytes_to_drop, b->current_length);
1557 vlib_buffer_advance (b, discard);
1558 b = vlib_get_buffer (vm, b->next_buffer);
1559 n_bytes_to_drop -= discard;
1561 while (n_bytes_to_drop);
1562 if (n_bytes_to_drop > first)
1563 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1566 vlib_buffer_advance (b, n_bytes_to_drop);
1567 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1572 * Receive buffer for connection and handle acks
1574 * It handles both in order or out-of-order data.
1577 tcp_segment_rcv (tcp_connection_t * tc, vlib_buffer_t * b, u32 * next0)
1579 u32 error, n_bytes_to_drop, n_data_bytes;
1581 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1582 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1583 ASSERT (n_data_bytes);
1585 /* Handle out-of-order data */
1586 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1588 /* Old sequence numbers allowed through because they overlapped
1590 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1592 /* Completely in the past (possible retransmit). Ack
1593 * retransmissions since we may not have any data to send */
1594 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1596 tcp_make_ack (tc, b);
1597 error = TCP_ERROR_SEGMENT_OLD;
1598 *next0 = tcp_next_output (tc->c_is_ip4);
1602 /* Chop off the bytes in the past and see if what is left
1603 * can be enqueued in order */
1604 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1605 n_data_bytes -= n_bytes_to_drop;
1606 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1607 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1609 error = TCP_ERROR_SEGMENT_OLD;
1610 *next0 = tcp_next_drop (tc->c_is_ip4);
1616 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1617 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1618 *next0 = tcp_next_output (tc->c_is_ip4);
1619 tcp_make_ack (tc, b);
1620 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1621 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1627 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1628 * segments can be enqueued after fifo tail offset changes. */
1629 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1630 if (tcp_can_delack (tc))
1632 *next0 = tcp_next_drop (tc->c_is_ip4);
1633 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1634 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1638 *next0 = tcp_next_output (tc->c_is_ip4);
1639 tcp_make_ack (tc, b);
1647 tcp_header_t tcp_header;
1648 tcp_connection_t tcp_connection;
1652 format_tcp_rx_trace (u8 * s, va_list * args)
1654 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1655 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1656 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1657 u32 indent = format_get_indent (s);
1659 s = format (s, "%U\n%U%U",
1660 format_tcp_header, &t->tcp_header, 128,
1661 format_white_space, indent,
1662 format_tcp_connection, &t->tcp_connection, 1);
1668 format_tcp_rx_trace_short (u8 * s, va_list * args)
1670 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1671 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1672 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1674 s = format (s, "%d -> %d (%U)",
1675 clib_net_to_host_u16 (t->tcp_header.dst_port),
1676 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1677 t->tcp_connection.state);
1683 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1684 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1688 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1692 th0 = tcp_buffer_hdr (b0);
1694 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1698 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
1699 vlib_frame_t * frame, u8 is_ip4)
1703 n_left = frame->n_vectors;
1704 from = vlib_frame_vector_args (frame);
1708 tcp_connection_t *tc0;
1715 b0 = vlib_get_buffer (vm, bi0);
1717 if (b0->flags & VLIB_BUFFER_IS_TRACED)
1719 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1720 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1722 th0 = tcp_buffer_hdr (b0);
1723 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1732 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1733 u8 is_ip4, u32 evt, u32 val)
1736 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1738 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1741 #define tcp_maybe_inc_counter(node_id, err, count) \
1743 if (next0 != tcp_next_drop (is_ip4)) \
1744 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1745 tcp6_##node_id##_node.index, is_ip4, err, \
1748 #define tcp_inc_counter(node_id, err, count) \
1749 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1750 tcp6_##node_id##_node.index, is_ip4, \
1752 #define tcp_maybe_inc_err_counter(cnts, err) \
1754 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
1756 #define tcp_inc_err_counter(cnts, err, val) \
1760 #define tcp_store_err_counters(node_id, cnts) \
1763 for (i = 0; i < TCP_N_ERROR; i++) \
1765 tcp_inc_counter(node_id, i, cnts[i]); \
1770 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1771 vlib_frame_t * frame, int is_ip4)
1773 u32 thread_index = vm->thread_index, errors = 0;
1774 u32 n_left_from, next_index, *from, *to_next;
1775 u16 err_counters[TCP_N_ERROR] = { 0 };
1778 if (node->flags & VLIB_NODE_FLAG_TRACE)
1779 tcp_established_trace_frame (vm, node, frame, is_ip4);
1781 from = vlib_frame_vector_args (frame);
1782 n_left_from = frame->n_vectors;
1783 next_index = node->cached_next_index;
1785 while (n_left_from > 0)
1789 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1790 while (n_left_from > 0 && n_left_to_next > 0)
1794 tcp_header_t *th0 = 0;
1795 tcp_connection_t *tc0;
1796 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ACK_OK;
1798 if (n_left_from > 1)
1801 pb = vlib_get_buffer (vm, from[1]);
1802 vlib_prefetch_buffer_header (pb, LOAD);
1803 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
1811 n_left_to_next -= 1;
1813 b0 = vlib_get_buffer (vm, bi0);
1814 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1817 if (PREDICT_FALSE (tc0 == 0))
1819 error0 = TCP_ERROR_INVALID_CONNECTION;
1823 th0 = tcp_buffer_hdr (b0);
1824 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1825 * dangling reference. */
1826 is_fin = tcp_is_fin (th0);
1828 /* SYNs, FINs and data consume sequence numbers */
1829 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1830 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1832 /* TODO header prediction fast path */
1834 /* 1-4: check SEQ, RST, SYN */
1835 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0,
1838 tcp_maybe_inc_err_counter (err_counters, error0);
1839 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
1843 /* 5: check the ACK field */
1844 if (PREDICT_FALSE (tcp_rcv_ack (tc0, b0, th0, &next0, &error0)))
1846 tcp_maybe_inc_err_counter (err_counters, error0);
1850 /* 6: check the URG bit TODO */
1852 /* 7: process the segment text */
1853 if (vnet_buffer (b0)->tcp.data_len)
1855 error0 = tcp_segment_rcv (tc0, b0, &next0);
1856 tcp_maybe_inc_err_counter (err_counters, error0);
1859 /* 8: check the FIN bit */
1860 if (PREDICT_FALSE (is_fin))
1862 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1863 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1864 /* Account for the FIN if nothing else was received */
1865 if (vnet_buffer (b0)->tcp.data_len == 0)
1867 tcp_make_ack (tc0, b0);
1868 next0 = tcp_next_output (tc0->c_is_ip4);
1869 tc0->state = TCP_STATE_CLOSE_WAIT;
1870 stream_session_disconnect_notify (&tc0->connection);
1871 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1872 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1873 tcp_inc_err_counter (err_counters, TCP_ERROR_FIN_RCVD, 1);
1877 b0->error = node->errors[error0];
1878 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1879 n_left_to_next, bi0, next0);
1882 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1885 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
1887 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
1888 tcp_store_err_counters (established, err_counters);
1889 tcp_flush_frame_to_output (vm, thread_index, is_ip4);
1891 return frame->n_vectors;
1895 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1896 vlib_frame_t * from_frame)
1898 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1902 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1903 vlib_frame_t * from_frame)
1905 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1909 VLIB_REGISTER_NODE (tcp4_established_node) =
1911 .function = tcp4_established,
1912 .name = "tcp4-established",
1913 /* Takes a vector of packets. */
1914 .vector_size = sizeof (u32),
1915 .n_errors = TCP_N_ERROR,
1916 .error_strings = tcp_error_strings,
1917 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1920 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1921 foreach_tcp_state_next
1924 .format_trace = format_tcp_rx_trace_short,
1928 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1931 VLIB_REGISTER_NODE (tcp6_established_node) =
1933 .function = tcp6_established,
1934 .name = "tcp6-established",
1935 /* Takes a vector of packets. */
1936 .vector_size = sizeof (u32),
1937 .n_errors = TCP_N_ERROR,
1938 .error_strings = tcp_error_strings,
1939 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1942 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1943 foreach_tcp_state_next
1946 .format_trace = format_tcp_rx_trace_short,
1951 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1953 vlib_node_registration_t tcp4_syn_sent_node;
1954 vlib_node_registration_t tcp6_syn_sent_node;
1957 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
1959 transport_connection_t *tmp = 0;
1966 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
1969 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
1970 && (tc->state == TCP_STATE_LISTEN
1971 || tc->c_rmt_port == hdr->src_port));
1975 handle = session_lookup_half_open_handle (&tc->connection);
1976 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
1977 tc->c_proto, tc->c_is_ip4);
1981 if (tmp->lcl_port == hdr->dst_port
1982 && tmp->rmt_port == hdr->src_port)
1984 TCP_DBG ("half-open is valid!");
1992 * Lookup transport connection
1994 static tcp_connection_t *
1995 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
1999 transport_connection_t *tconn;
2000 tcp_connection_t *tc;
2005 ip4 = vlib_buffer_get_current (b);
2006 tcp = ip4_next_header (ip4);
2007 tconn = session_lookup_connection_wt4 (fib_index,
2012 TRANSPORT_PROTO_TCP,
2013 thread_index, &is_filtered);
2014 tc = tcp_get_connection_from_transport (tconn);
2015 ASSERT (tcp_lookup_is_valid (tc, tcp));
2020 ip6 = vlib_buffer_get_current (b);
2021 tcp = ip6_next_header (ip6);
2022 tconn = session_lookup_connection_wt6 (fib_index,
2027 TRANSPORT_PROTO_TCP,
2028 thread_index, &is_filtered);
2029 tc = tcp_get_connection_from_transport (tconn);
2030 ASSERT (tcp_lookup_is_valid (tc, tcp));
2036 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2037 vlib_frame_t * from_frame, int is_ip4)
2039 tcp_main_t *tm = vnet_get_tcp_main ();
2040 u32 n_left_from, next_index, *from, *to_next;
2041 u32 my_thread_index = vm->thread_index, errors = 0;
2043 from = vlib_frame_vector_args (from_frame);
2044 n_left_from = from_frame->n_vectors;
2046 next_index = node->cached_next_index;
2048 while (n_left_from > 0)
2052 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2054 while (n_left_from > 0 && n_left_to_next > 0)
2056 u32 bi0, ack0, seq0;
2059 tcp_header_t *tcp0 = 0;
2060 tcp_connection_t *tc0;
2061 tcp_connection_t *new_tc0;
2062 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
2069 n_left_to_next -= 1;
2071 b0 = vlib_get_buffer (vm, bi0);
2073 tcp_half_open_connection_get (vnet_buffer (b0)->
2074 tcp.connection_index);
2075 if (PREDICT_FALSE (tc0 == 0))
2077 error0 = TCP_ERROR_INVALID_CONNECTION;
2081 /* Half-open completed recently but the connection was't removed
2082 * yet by the owning thread */
2083 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2085 /* Make sure the connection actually exists */
2086 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2087 my_thread_index, is_ip4));
2091 ack0 = vnet_buffer (b0)->tcp.ack_number;
2092 seq0 = vnet_buffer (b0)->tcp.seq_number;
2093 tcp0 = tcp_buffer_hdr (b0);
2095 /* Crude check to see if the connection handle does not match
2096 * the packet. Probably connection just switched to established */
2097 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2098 || tcp0->src_port != tc0->c_rmt_port))
2102 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
2105 /* SYNs, FINs and data consume sequence numbers */
2106 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
2107 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
2110 * 1. check the ACK bit
2114 * If the ACK bit is set
2115 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2116 * the RST bit is set, if so drop the segment and return)
2117 * <SEQ=SEG.ACK><CTL=RST>
2118 * and discard the segment. Return.
2119 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2123 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2125 clib_warning ("ack not in rcv wnd");
2126 if (!tcp_rst (tcp0))
2127 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2131 /* Make sure ACK is valid */
2132 if (seq_gt (tc0->snd_una, ack0))
2134 clib_warning ("ack invalid");
2140 * 2. check the RST bit
2145 /* If ACK is acceptable, signal client that peer is not
2146 * willing to accept connection and drop connection*/
2148 tcp_connection_reset (tc0);
2153 * 3. check the security and precedence (skipped)
2157 * 4. check the SYN bit
2160 /* No SYN flag. Drop. */
2161 if (!tcp_syn (tcp0))
2163 clib_warning ("not synack");
2168 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2170 clib_warning ("options parse fail");
2174 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2175 * current thread pool. */
2176 pool_get (tm->connections[my_thread_index], new_tc0);
2177 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2178 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2179 new_tc0->c_thread_index = my_thread_index;
2180 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2181 new_tc0->irs = seq0;
2182 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2183 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2184 TCP_TIMER_HANDLE_INVALID;
2185 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2187 /* If this is not the owning thread, wait for syn retransmit to
2188 * expire and cleanup then */
2189 if (tcp_half_open_connection_cleanup (tc0))
2190 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2192 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2194 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2195 new_tc0->tsval_recent_age = tcp_time_now ();
2198 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2199 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2201 /* RFC1323: SYN and SYN-ACK wnd not scaled */
2202 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
2203 new_tc0->snd_wl1 = seq0;
2204 new_tc0->snd_wl2 = ack0;
2206 tcp_connection_init_vars (new_tc0);
2208 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2209 if (PREDICT_TRUE (tcp_ack (tcp0)))
2211 /* Our SYN is ACKed: we have iss < ack = snd_una */
2213 /* TODO Dequeue acknowledged segments if we support Fast Open */
2214 new_tc0->snd_una = ack0;
2215 new_tc0->state = TCP_STATE_ESTABLISHED;
2217 /* Make sure las is initialized for the wnd computation */
2218 new_tc0->rcv_las = new_tc0->rcv_nxt;
2220 /* Notify app that we have connection. If session layer can't
2221 * allocate session send reset */
2222 if (session_stream_connect_notify (&new_tc0->connection, 0))
2224 clib_warning ("connect notify fail");
2225 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2226 tcp_connection_cleanup (new_tc0);
2230 /* Make sure after data segment processing ACK is sent */
2231 new_tc0->flags |= TCP_CONN_SNDACK;
2233 /* Update rtt with the syn-ack sample */
2234 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2235 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2237 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2240 new_tc0->state = TCP_STATE_SYN_RCVD;
2242 /* Notify app that we have connection */
2243 if (session_stream_connect_notify (&new_tc0->connection, 0))
2245 tcp_connection_cleanup (new_tc0);
2246 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2247 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2252 tcp_init_snd_vars (tc0);
2253 tcp_make_synack (new_tc0, b0);
2254 next0 = tcp_next_output (is_ip4);
2259 /* Read data, if any */
2260 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2262 clib_warning ("rcvd data in syn-sent");
2263 error0 = tcp_segment_rcv (new_tc0, b0, &next0);
2264 if (error0 == TCP_ERROR_ACK_OK)
2265 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2266 tcp_maybe_inc_counter (syn_sent, error0, 1);
2270 tcp_make_ack (new_tc0, b0);
2271 next0 = tcp_next_output (new_tc0->c_is_ip4);
2276 b0->error = error0 ? node->errors[error0] : 0;
2278 ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2280 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2281 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2282 clib_memcpy (&t0->tcp_connection, tc0,
2283 sizeof (t0->tcp_connection));
2286 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2287 n_left_to_next, bi0, next0);
2290 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2293 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2295 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2296 return from_frame->n_vectors;
2300 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2301 vlib_frame_t * from_frame)
2303 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2307 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2308 vlib_frame_t * from_frame)
2310 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2314 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2316 .function = tcp4_syn_sent,
2317 .name = "tcp4-syn-sent",
2318 /* Takes a vector of packets. */
2319 .vector_size = sizeof (u32),
2320 .n_errors = TCP_N_ERROR,
2321 .error_strings = tcp_error_strings,
2322 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2325 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2326 foreach_tcp_state_next
2329 .format_trace = format_tcp_rx_trace_short,
2333 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2336 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2338 .function = tcp6_syn_sent_rcv,
2339 .name = "tcp6-syn-sent",
2340 /* Takes a vector of packets. */
2341 .vector_size = sizeof (u32),
2342 .n_errors = TCP_N_ERROR,
2343 .error_strings = tcp_error_strings,
2344 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2347 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2348 foreach_tcp_state_next
2351 .format_trace = format_tcp_rx_trace_short,
2355 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2357 vlib_node_registration_t tcp4_rcv_process_node;
2358 vlib_node_registration_t tcp6_rcv_process_node;
2361 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2362 * as per RFC793 p. 64
2365 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2366 vlib_frame_t * from_frame, int is_ip4)
2368 u32 n_left_from, next_index, *from, *to_next, n_fins = 0;
2369 u32 my_thread_index = vm->thread_index, errors = 0;
2371 from = vlib_frame_vector_args (from_frame);
2372 n_left_from = from_frame->n_vectors;
2373 next_index = node->cached_next_index;
2375 while (n_left_from > 0)
2379 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2381 while (n_left_from > 0 && n_left_to_next > 0)
2385 tcp_header_t *tcp0 = 0;
2386 tcp_connection_t *tc0;
2387 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_NONE;
2395 n_left_to_next -= 1;
2397 b0 = vlib_get_buffer (vm, bi0);
2398 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2400 if (PREDICT_FALSE (tc0 == 0))
2402 error0 = TCP_ERROR_INVALID_CONNECTION;
2406 tcp0 = tcp_buffer_hdr (b0);
2407 is_fin0 = tcp_is_fin (tcp0);
2409 /* SYNs, FINs and data consume sequence numbers */
2410 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2411 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2415 tcp_connection_t *tmp;
2416 tmp = tcp_lookup_connection (tc0->c_fib_index, b0,
2417 my_thread_index, is_ip4);
2418 if (tmp->state != tc0->state)
2420 clib_warning ("state changed");
2426 * Special treatment for CLOSED
2428 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2430 error0 = TCP_ERROR_CONNECTION_CLOSED;
2435 * For all other states (except LISTEN)
2438 /* 1-4: check SEQ, RST, SYN */
2439 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2442 tcp_maybe_inc_counter (rcv_process, error0, 1);
2446 /* 5: check the ACK field */
2449 case TCP_STATE_SYN_RCVD:
2451 * If the segment acknowledgment is not acceptable, form a
2453 * <SEQ=SEG.ACK><CTL=RST>
2456 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2458 TCP_DBG ("connection not accepted");
2459 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2460 error0 = TCP_ERROR_ACK_INVALID;
2464 /* Update rtt and rto */
2465 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2467 /* Switch state to ESTABLISHED */
2468 tc0->state = TCP_STATE_ESTABLISHED;
2469 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2471 /* Initialize session variables */
2472 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2473 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2474 << tc0->rcv_opts.wscale;
2475 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2476 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2478 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2479 tcp_retransmit_timer_reset (tc0);
2480 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2481 stream_session_accept_notify (&tc0->connection);
2482 error0 = TCP_ERROR_ACK_OK;
2484 case TCP_STATE_ESTABLISHED:
2485 /* We can get packets in established state here because they
2486 * were enqueued before state change */
2487 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2489 tcp_maybe_inc_counter (rcv_process, error0, 1);
2494 case TCP_STATE_FIN_WAIT_1:
2495 /* In addition to the processing for the ESTABLISHED state, if
2496 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2497 * continue processing in that state. */
2498 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2500 tcp_maybe_inc_counter (rcv_process, error0, 1);
2504 /* Still have to send the FIN */
2505 if (tc0->flags & TCP_CONN_FINPNDG)
2507 /* TX fifo finally drained */
2508 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2511 /* If FIN is ACKed */
2512 else if (tc0->snd_una == tc0->snd_una_max)
2514 tc0->state = TCP_STATE_FIN_WAIT_2;
2515 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2517 /* Stop all retransmit timers because we have nothing more
2518 * to send. Enable waitclose though because we're willing to
2519 * wait for peer's FIN but not indefinitely. */
2520 tcp_connection_timers_reset (tc0);
2521 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2524 case TCP_STATE_FIN_WAIT_2:
2525 /* In addition to the processing for the ESTABLISHED state, if
2526 * the retransmission queue is empty, the user's CLOSE can be
2527 * acknowledged ("ok") but do not delete the TCB. */
2528 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2530 tcp_maybe_inc_counter (rcv_process, error0, 1);
2534 case TCP_STATE_CLOSE_WAIT:
2535 /* Do the same processing as for the ESTABLISHED state. */
2536 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2538 tcp_maybe_inc_counter (rcv_process, error0, 1);
2541 if (tc0->flags & TCP_CONN_FINPNDG)
2543 /* TX fifo finally drained */
2544 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2547 tcp_connection_timers_reset (tc0);
2548 tc0->state = TCP_STATE_LAST_ACK;
2549 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2554 case TCP_STATE_CLOSING:
2555 /* In addition to the processing for the ESTABLISHED state, if
2556 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2557 * otherwise ignore the segment. */
2558 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2560 tcp_maybe_inc_counter (rcv_process, error0, 1);
2564 tc0->state = TCP_STATE_TIME_WAIT;
2565 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2566 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2570 case TCP_STATE_LAST_ACK:
2571 /* The only thing that [should] arrive in this state is an
2572 * acknowledgment of our FIN. If our FIN is now acknowledged,
2573 * delete the TCB, enter the CLOSED state, and return. */
2575 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2577 error0 = TCP_ERROR_ACK_INVALID;
2580 error0 = TCP_ERROR_ACK_OK;
2581 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2582 /* Apparently our ACK for the peer's FIN was lost */
2583 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2589 tc0->state = TCP_STATE_CLOSED;
2590 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2591 /* Delete the connection/session since the pipes should be
2593 tcp_connection_del (tc0);
2598 case TCP_STATE_TIME_WAIT:
2599 /* The only thing that can arrive in this state is a
2600 * retransmission of the remote FIN. Acknowledge it, and restart
2601 * the 2 MSL timeout. */
2603 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2605 tcp_maybe_inc_counter (rcv_process, error0, 1);
2609 tcp_make_ack (tc0, b0);
2610 next0 = tcp_next_output (is_ip4);
2611 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2619 /* 6: check the URG bit TODO */
2621 /* 7: process the segment text */
2624 case TCP_STATE_ESTABLISHED:
2625 case TCP_STATE_FIN_WAIT_1:
2626 case TCP_STATE_FIN_WAIT_2:
2627 if (vnet_buffer (b0)->tcp.data_len)
2629 error0 = tcp_segment_rcv (tc0, b0, &next0);
2630 tcp_maybe_inc_counter (rcv_process, error0, 1);
2635 case TCP_STATE_CLOSE_WAIT:
2636 case TCP_STATE_CLOSING:
2637 case TCP_STATE_LAST_ACK:
2638 case TCP_STATE_TIME_WAIT:
2639 /* This should not occur, since a FIN has been received from the
2640 * remote side. Ignore the segment text. */
2644 /* 8: check the FIN bit */
2650 case TCP_STATE_ESTABLISHED:
2651 case TCP_STATE_SYN_RCVD:
2652 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2653 tcp_connection_timers_reset (tc0);
2654 tcp_retransmit_timer_set (tc0);
2655 tcp_make_fin (tc0, b0);
2657 tc0->snd_una_max = tc0->snd_nxt;
2658 next0 = tcp_next_output (tc0->c_is_ip4);
2659 stream_session_disconnect_notify (&tc0->connection);
2660 tc0->state = TCP_STATE_CLOSE_WAIT;
2661 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2663 case TCP_STATE_CLOSE_WAIT:
2664 case TCP_STATE_CLOSING:
2665 case TCP_STATE_LAST_ACK:
2668 case TCP_STATE_FIN_WAIT_1:
2669 tc0->state = TCP_STATE_CLOSING;
2670 tcp_make_ack (tc0, b0);
2671 next0 = tcp_next_output (is_ip4);
2672 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2673 /* Wait for ACK but not forever */
2674 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2676 case TCP_STATE_FIN_WAIT_2:
2677 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2678 tc0->state = TCP_STATE_TIME_WAIT;
2679 tcp_connection_timers_reset (tc0);
2680 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2681 tcp_make_ack (tc0, b0);
2682 next0 = tcp_next_output (is_ip4);
2683 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2685 case TCP_STATE_TIME_WAIT:
2686 /* Remain in the TIME-WAIT state. Restart the time-wait
2689 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2692 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2696 b0->error = error0 ? node->errors[error0] : 0;
2698 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2700 tcp_rx_trace_t *t0 =
2701 vlib_add_trace (vm, node, b0, sizeof (*t0));
2702 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2705 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2706 n_left_to_next, bi0, next0);
2709 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2712 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2714 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2715 tcp_inc_counter (rcv_process, TCP_ERROR_FIN_RCVD, n_fins);
2716 return from_frame->n_vectors;
2720 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2721 vlib_frame_t * from_frame)
2723 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2727 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2728 vlib_frame_t * from_frame)
2730 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2734 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2736 .function = tcp4_rcv_process,
2737 .name = "tcp4-rcv-process",
2738 /* Takes a vector of packets. */
2739 .vector_size = sizeof (u32),
2740 .n_errors = TCP_N_ERROR,
2741 .error_strings = tcp_error_strings,
2742 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2745 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2746 foreach_tcp_state_next
2749 .format_trace = format_tcp_rx_trace_short,
2753 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2756 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2758 .function = tcp6_rcv_process,
2759 .name = "tcp6-rcv-process",
2760 /* Takes a vector of packets. */
2761 .vector_size = sizeof (u32),
2762 .n_errors = TCP_N_ERROR,
2763 .error_strings = tcp_error_strings,
2764 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2767 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2768 foreach_tcp_state_next
2771 .format_trace = format_tcp_rx_trace_short,
2775 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2777 vlib_node_registration_t tcp4_listen_node;
2778 vlib_node_registration_t tcp6_listen_node;
2781 * LISTEN state processing as per RFC 793 p. 65
2784 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2785 vlib_frame_t * from_frame, int is_ip4)
2787 u32 n_left_from, next_index, *from, *to_next, n_syns = 0;
2788 u32 my_thread_index = vm->thread_index;
2790 from = vlib_frame_vector_args (from_frame);
2791 n_left_from = from_frame->n_vectors;
2793 next_index = node->cached_next_index;
2795 while (n_left_from > 0)
2799 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2801 while (n_left_from > 0 && n_left_to_next > 0)
2806 tcp_header_t *th0 = 0;
2807 tcp_connection_t *lc0;
2810 tcp_connection_t *child0;
2811 u32 error0 = TCP_ERROR_NONE, next0 = tcp_next_drop (is_ip4);
2818 n_left_to_next -= 1;
2820 b0 = vlib_get_buffer (vm, bi0);
2821 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2825 ip40 = vlib_buffer_get_current (b0);
2826 th0 = ip4_next_header (ip40);
2830 ip60 = vlib_buffer_get_current (b0);
2831 th0 = ip6_next_header (ip60);
2834 /* Create child session. For syn-flood protection use filter */
2836 /* 1. first check for an RST: handled in dispatch */
2837 /* if (tcp_rst (th0))
2840 /* 2. second check for an ACK: handled in dispatch */
2841 /* if (tcp_ack (th0))
2843 tcp_send_reset (b0, is_ip4);
2847 /* 3. check for a SYN (did that already) */
2849 /* Make sure connection wasn't just created */
2850 child0 = tcp_lookup_connection (lc0->c_fib_index, b0,
2851 my_thread_index, is_ip4);
2852 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
2854 error0 = TCP_ERROR_CREATE_EXISTS;
2858 /* Create child session and send SYN-ACK */
2859 child0 = tcp_connection_new (my_thread_index);
2860 child0->c_lcl_port = th0->dst_port;
2861 child0->c_rmt_port = th0->src_port;
2862 child0->c_is_ip4 = is_ip4;
2863 child0->state = TCP_STATE_SYN_RCVD;
2864 child0->c_fib_index = lc0->c_fib_index;
2868 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2869 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2873 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2874 sizeof (ip6_address_t));
2875 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2876 sizeof (ip6_address_t));
2879 if (tcp_options_parse (th0, &child0->rcv_opts))
2881 clib_warning ("options parse fail");
2885 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2886 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2887 child0->rcv_las = child0->rcv_nxt;
2888 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2890 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2891 * segments are used to initialize PAWS. */
2892 if (tcp_opts_tstamp (&child0->rcv_opts))
2894 child0->tsval_recent = child0->rcv_opts.tsval;
2895 child0->tsval_recent_age = tcp_time_now ();
2898 if (tcp_opts_wscale (&child0->rcv_opts))
2899 child0->snd_wscale = child0->rcv_opts.wscale;
2901 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2902 << child0->snd_wscale;
2903 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2904 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2906 tcp_connection_init_vars (child0);
2907 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
2909 if (stream_session_accept (&child0->connection, lc0->c_s_index,
2912 clib_warning ("session accept fail");
2913 tcp_connection_cleanup (child0);
2914 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2918 /* Reuse buffer to make syn-ack and send */
2919 tcp_make_synack (child0, b0);
2920 next0 = tcp_next_output (is_ip4);
2921 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
2924 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2926 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2927 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2928 clib_memcpy (&t0->tcp_connection, lc0,
2929 sizeof (t0->tcp_connection));
2932 n_syns += (error0 == TCP_ERROR_NONE);
2933 b0->error = node->errors[error0];
2935 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2936 n_left_to_next, bi0, next0);
2939 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2942 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
2943 return from_frame->n_vectors;
2947 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2948 vlib_frame_t * from_frame)
2950 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2954 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2955 vlib_frame_t * from_frame)
2957 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2961 VLIB_REGISTER_NODE (tcp4_listen_node) =
2963 .function = tcp4_listen,
2964 .name = "tcp4-listen",
2965 /* Takes a vector of packets. */
2966 .vector_size = sizeof (u32),
2967 .n_errors = TCP_N_ERROR,
2968 .error_strings = tcp_error_strings,
2969 .n_next_nodes = TCP_LISTEN_N_NEXT,
2972 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2973 foreach_tcp_state_next
2976 .format_trace = format_tcp_rx_trace_short,
2980 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2983 VLIB_REGISTER_NODE (tcp6_listen_node) =
2985 .function = tcp6_listen,
2986 .name = "tcp6-listen",
2987 /* Takes a vector of packets. */
2988 .vector_size = sizeof (u32),
2989 .n_errors = TCP_N_ERROR,
2990 .error_strings = tcp_error_strings,
2991 .n_next_nodes = TCP_LISTEN_N_NEXT,
2994 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2995 foreach_tcp_state_next
2998 .format_trace = format_tcp_rx_trace_short,
3002 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3004 vlib_node_registration_t tcp4_input_node;
3005 vlib_node_registration_t tcp6_input_node;
3007 typedef enum _tcp_input_next
3009 TCP_INPUT_NEXT_DROP,
3010 TCP_INPUT_NEXT_LISTEN,
3011 TCP_INPUT_NEXT_RCV_PROCESS,
3012 TCP_INPUT_NEXT_SYN_SENT,
3013 TCP_INPUT_NEXT_ESTABLISHED,
3014 TCP_INPUT_NEXT_RESET,
3015 TCP_INPUT_NEXT_PUNT,
3019 #define foreach_tcp4_input_next \
3020 _ (DROP, "ip4-drop") \
3021 _ (LISTEN, "tcp4-listen") \
3022 _ (RCV_PROCESS, "tcp4-rcv-process") \
3023 _ (SYN_SENT, "tcp4-syn-sent") \
3024 _ (ESTABLISHED, "tcp4-established") \
3025 _ (RESET, "tcp4-reset") \
3026 _ (PUNT, "ip4-punt")
3028 #define foreach_tcp6_input_next \
3029 _ (DROP, "ip6-drop") \
3030 _ (LISTEN, "tcp6-listen") \
3031 _ (RCV_PROCESS, "tcp6-rcv-process") \
3032 _ (SYN_SENT, "tcp6-syn-sent") \
3033 _ (ESTABLISHED, "tcp6-established") \
3034 _ (RESET, "tcp6-reset") \
3035 _ (PUNT, "ip6-punt")
3037 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3040 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3041 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3043 tcp_connection_t *tc;
3048 for (i = 0; i < n_bufs; i++)
3050 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3052 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3053 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3055 tcp = vlib_buffer_get_current (bs[i]);
3056 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3062 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3064 if (*error == TCP_ERROR_FILTERED)
3066 *next = TCP_INPUT_NEXT_DROP;
3068 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3070 *next = TCP_INPUT_NEXT_PUNT;
3071 *error = TCP_ERROR_PUNT;
3075 *next = TCP_INPUT_NEXT_RESET;
3076 *error = TCP_ERROR_NO_LISTENER;
3080 static inline tcp_connection_t *
3081 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3084 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3085 int n_advance_bytes, n_data_bytes;
3086 transport_connection_t *tc;
3092 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3093 tcp = ip4_next_header (ip4);
3094 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3095 n_advance_bytes = (ip4_header_bytes (ip4) + tcp_header_bytes (tcp));
3096 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3098 /* Length check. Checksum computed by ipx_local no need to compute again */
3099 if (PREDICT_FALSE (n_advance_bytes < 0))
3101 *error = TCP_ERROR_LENGTH;
3105 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3106 &ip4->src_address, tcp->dst_port,
3107 tcp->src_port, TRANSPORT_PROTO_TCP,
3108 thread_index, &is_filtered);
3112 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3113 tcp = ip6_next_header (ip6);
3114 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3115 n_advance_bytes = tcp_header_bytes (tcp);
3116 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3118 n_advance_bytes += sizeof (ip6[0]);
3120 if (PREDICT_FALSE (n_advance_bytes < 0))
3122 *error = TCP_ERROR_LENGTH;
3126 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3127 &ip6->src_address, tcp->dst_port,
3128 tcp->src_port, TRANSPORT_PROTO_TCP,
3129 thread_index, &is_filtered);
3132 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3133 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3134 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3135 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3136 vnet_buffer (b)->tcp.flags = 0;
3138 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3140 return tcp_get_connection_from_transport (tc);
3144 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3145 vlib_buffer_t * b, u16 * next, u32 * error)
3150 tcp = tcp_buffer_hdr (b);
3151 flags = tcp->flags & filter_flags;
3152 *next = tm->dispatch_table[tc->state][flags].next;
3153 *error = tm->dispatch_table[tc->state][flags].error;
3155 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3156 || *next == TCP_INPUT_NEXT_RESET))
3158 /* Overload tcp flags to store state */
3159 tcp_state_t state = tc->state;
3160 vnet_buffer (b)->tcp.flags = tc->state;
3162 if (*error == TCP_ERROR_DISPATCH)
3163 clib_warning ("disp error state %U flags %U", format_tcp_state,
3164 state, format_tcp_flags, (int) flags);
3169 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3170 vlib_frame_t * frame, int is_ip4)
3172 u32 n_left_from, *from, thread_index = vm->thread_index;
3173 tcp_main_t *tm = vnet_get_tcp_main ();
3174 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3175 u16 nexts[VLIB_FRAME_SIZE], *next;
3177 tcp_set_time_now (thread_index);
3179 from = vlib_frame_vector_args (frame);
3180 n_left_from = frame->n_vectors;
3181 vlib_get_buffers (vm, from, bufs, n_left_from);
3186 while (n_left_from >= 4)
3188 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3189 tcp_connection_t *tc0, *tc1;
3192 vlib_prefetch_buffer_header (b[2], STORE);
3193 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3195 vlib_prefetch_buffer_header (b[3], STORE);
3196 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3199 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3201 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3202 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3204 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3206 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3207 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3209 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3210 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3212 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3213 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3217 if (PREDICT_TRUE (tc0 != 0))
3219 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3220 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3221 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3224 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3226 if (PREDICT_TRUE (tc1 != 0))
3228 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3229 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3230 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3233 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3240 while (n_left_from > 0)
3242 tcp_connection_t *tc0;
3243 u32 error0 = TCP_ERROR_NO_LISTENER;
3245 if (n_left_from > 1)
3247 vlib_prefetch_buffer_header (b[1], STORE);
3248 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3251 next[0] = TCP_INPUT_NEXT_DROP;
3252 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3253 if (PREDICT_TRUE (tc0 != 0))
3255 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3256 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3257 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3260 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3267 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3268 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3270 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3271 return frame->n_vectors;
3275 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3276 vlib_frame_t * from_frame)
3278 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3282 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3283 vlib_frame_t * from_frame)
3285 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3289 VLIB_REGISTER_NODE (tcp4_input_node) =
3291 .function = tcp4_input,
3292 .name = "tcp4-input",
3293 /* Takes a vector of packets. */
3294 .vector_size = sizeof (u32),
3295 .n_errors = TCP_N_ERROR,
3296 .error_strings = tcp_error_strings,
3297 .n_next_nodes = TCP_INPUT_N_NEXT,
3300 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3301 foreach_tcp4_input_next
3304 .format_buffer = format_tcp_header,
3305 .format_trace = format_tcp_rx_trace,
3309 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3312 VLIB_REGISTER_NODE (tcp6_input_node) =
3314 .function = tcp6_input,
3315 .name = "tcp6-input",
3316 /* Takes a vector of packets. */
3317 .vector_size = sizeof (u32),
3318 .n_errors = TCP_N_ERROR,
3319 .error_strings = tcp_error_strings,
3320 .n_next_nodes = TCP_INPUT_N_NEXT,
3323 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3324 foreach_tcp6_input_next
3327 .format_buffer = format_tcp_header,
3328 .format_trace = format_tcp_rx_trace,
3332 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3335 tcp_dispatch_table_init (tcp_main_t * tm)
3338 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3339 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3341 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3342 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3345 #define _(t,f,n,e) \
3347 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3348 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3351 /* SYNs for new connections -> tcp-listen. */
3352 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3353 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3354 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3355 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3357 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3358 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3359 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3360 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3361 /* SYN-ACK for a SYN */
3362 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3364 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3365 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3366 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3368 /* ACK for for established connection -> tcp-established. */
3369 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3370 /* FIN for for established connection -> tcp-established. */
3371 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3372 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3374 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3375 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3377 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3378 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3380 /* ACK or FIN-ACK to our FIN */
3381 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3382 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3384 /* FIN in reply to our FIN from the other side */
3385 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3386 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3387 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3388 /* FIN confirming that the peer (app) has closed */
3389 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3390 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3391 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3393 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3394 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3396 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3397 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3398 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3400 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3401 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3402 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3404 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3405 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3406 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3407 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3408 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3409 TCP_ERROR_CONNECTION_CLOSED);
3414 tcp_input_init (vlib_main_t * vm)
3416 clib_error_t *error = 0;
3417 tcp_main_t *tm = vnet_get_tcp_main ();
3419 if ((error = vlib_call_init_function (vm, tcp_init)))
3422 /* Initialize dispatch table. */
3423 tcp_dispatch_table_init (tm);
3428 VLIB_INIT_FUNCTION (tcp_input_init);
3431 * fd.io coding-style-patch-verification: ON
3434 * eval: (c-set-style "gnu")