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)
457 if (tcp_in_recovery (tc))
462 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
464 mrtt = tcp_time_now () - tc->rtt_ts;
466 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
467 * snd_una, i.e., the left side of the send window:
468 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
469 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
471 mrtt = tcp_time_now () - tc->rcv_opts.tsecr;
474 /* Ignore dubious measurements */
475 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
478 tcp_estimate_rtt (tc, mrtt);
482 /* Allow measuring of a new RTT */
485 /* If we got here something must've been ACKed so make sure boff is 0,
486 * even if mrtt is not valid since we update the rto lower */
494 * Dequeue bytes that have been acked and while at it update RTT estimates.
497 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
499 /* Dequeue the newly ACKed add SACKed bytes */
500 stream_session_dequeue_drop (&tc->connection,
501 tc->bytes_acked + tc->sack_sb.snd_una_adv);
503 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
505 /* Update rtt and rto */
506 tcp_update_rtt (tc, ack);
508 /* If everything has been acked, stop retransmit timer
509 * otherwise update. */
510 tcp_retransmit_timer_update (tc);
514 * Check if duplicate ack as per RFC5681 Sec. 2
517 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
520 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
521 && seq_gt (tc->snd_una_max, tc->snd_una)
522 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
523 && (prev_snd_wnd == tc->snd_wnd));
527 * Checks if ack is a congestion control event.
530 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
531 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
533 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
534 * defined to be 'duplicate' */
535 *is_dack = tc->sack_sb.last_sacked_bytes
536 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
538 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
542 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
544 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
545 return hole - sb->holes;
549 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
551 return hole->end - hole->start;
554 sack_scoreboard_hole_t *
555 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
557 if (index != TCP_INVALID_SACK_HOLE_INDEX)
558 return pool_elt_at_index (sb->holes, index);
562 sack_scoreboard_hole_t *
563 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
565 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
566 return pool_elt_at_index (sb->holes, hole->next);
570 sack_scoreboard_hole_t *
571 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
573 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
574 return pool_elt_at_index (sb->holes, hole->prev);
578 sack_scoreboard_hole_t *
579 scoreboard_first_hole (sack_scoreboard_t * sb)
581 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
582 return pool_elt_at_index (sb->holes, sb->head);
586 sack_scoreboard_hole_t *
587 scoreboard_last_hole (sack_scoreboard_t * sb)
589 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
590 return pool_elt_at_index (sb->holes, sb->tail);
595 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
597 sack_scoreboard_hole_t *next, *prev;
599 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
601 next = pool_elt_at_index (sb->holes, hole->next);
602 next->prev = hole->prev;
606 sb->tail = hole->prev;
609 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
611 prev = pool_elt_at_index (sb->holes, hole->prev);
612 prev->next = hole->next;
616 sb->head = hole->next;
619 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
620 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
622 /* Poison the entry */
624 memset (hole, 0xfe, sizeof (*hole));
626 pool_put (sb->holes, hole);
629 static sack_scoreboard_hole_t *
630 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
633 sack_scoreboard_hole_t *hole, *next, *prev;
636 pool_get (sb->holes, hole);
637 memset (hole, 0, sizeof (*hole));
641 hole_index = scoreboard_hole_index (sb, hole);
643 prev = scoreboard_get_hole (sb, prev_index);
646 hole->prev = prev_index;
647 hole->next = prev->next;
649 if ((next = scoreboard_next_hole (sb, hole)))
650 next->prev = hole_index;
652 sb->tail = hole_index;
654 prev->next = hole_index;
658 sb->head = hole_index;
659 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
660 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
667 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
669 sack_scoreboard_hole_t *hole, *prev;
670 u32 bytes = 0, blks = 0;
673 sb->sacked_bytes = 0;
674 hole = scoreboard_last_hole (sb);
678 if (seq_gt (sb->high_sacked, hole->end))
680 bytes = sb->high_sacked - hole->end;
684 while ((prev = scoreboard_prev_hole (sb, hole))
685 && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
686 && blks < TCP_DUPACK_THRESHOLD))
688 bytes += hole->start - prev->end;
695 sb->lost_bytes += scoreboard_hole_bytes (hole);
698 hole = scoreboard_prev_hole (sb, hole);
700 bytes += prev->start - hole->end;
702 sb->sacked_bytes = bytes;
706 * Figure out the next hole to retransmit
708 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
710 sack_scoreboard_hole_t *
711 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
712 sack_scoreboard_hole_t * start,
714 u8 * can_rescue, u8 * snd_limited)
716 sack_scoreboard_hole_t *hole = 0;
718 hole = start ? start : scoreboard_first_hole (sb);
719 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
720 hole = scoreboard_next_hole (sb, hole);
722 /* Nothing, return */
725 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
729 /* Rule (1): if higher than rxt, less than high_sacked and lost */
730 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
732 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
736 /* Rule (2): output takes care of transmitting new data */
737 if (!have_sent_1_smss)
740 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
742 /* Rule (3): if hole not lost */
743 else if (seq_lt (hole->start, sb->high_sacked))
746 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
748 /* Rule (4): if hole beyond high_sacked */
751 ASSERT (seq_geq (hole->start, sb->high_sacked));
754 /* HighRxt MUST NOT be updated */
759 if (hole && seq_lt (sb->high_rxt, hole->start))
760 sb->high_rxt = hole->start;
766 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
768 sack_scoreboard_hole_t *hole;
769 hole = scoreboard_first_hole (sb);
772 seq = seq_gt (seq, hole->start) ? seq : hole->start;
773 sb->cur_rxt_hole = sb->head;
779 scoreboard_init (sack_scoreboard_t * sb)
781 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
782 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
783 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
787 scoreboard_clear (sack_scoreboard_t * sb)
789 sack_scoreboard_hole_t *hole;
790 while ((hole = scoreboard_first_hole (sb)))
792 scoreboard_remove_hole (sb, hole);
794 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
795 ASSERT (pool_elts (sb->holes) == 0);
796 sb->sacked_bytes = 0;
797 sb->last_sacked_bytes = 0;
798 sb->last_bytes_delivered = 0;
803 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
807 * Test that scoreboard is sane after recovery
809 * Returns 1 if scoreboard is empty or if first hole beyond
813 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
815 sack_scoreboard_hole_t *hole;
816 hole = scoreboard_first_hole (&tc->sack_sb);
817 return (!hole || seq_geq (hole->start, tc->snd_una));
821 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
823 sack_scoreboard_t *sb = &tc->sack_sb;
824 sack_block_t *blk, tmp;
825 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
826 u32 blk_index = 0, old_sacked_bytes, hole_index;
829 sb->last_sacked_bytes = 0;
830 sb->last_bytes_delivered = 0;
833 if (!tcp_opts_sack (&tc->rcv_opts)
834 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
837 old_sacked_bytes = sb->sacked_bytes;
839 /* Remove invalid blocks */
840 blk = tc->rcv_opts.sacks;
841 while (blk < vec_end (tc->rcv_opts.sacks))
843 if (seq_lt (blk->start, blk->end)
844 && seq_gt (blk->start, tc->snd_una)
845 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
850 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
853 /* Add block for cumulative ack */
854 if (seq_gt (ack, tc->snd_una))
856 tmp.start = tc->snd_una;
858 vec_add1 (tc->rcv_opts.sacks, tmp);
861 if (vec_len (tc->rcv_opts.sacks) == 0)
864 tcp_scoreboard_trace_add (tc, ack);
866 /* Make sure blocks are ordered */
867 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
868 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
869 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
871 tmp = tc->rcv_opts.sacks[i];
872 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
873 tc->rcv_opts.sacks[j] = tmp;
876 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
878 /* If no holes, insert the first that covers all outstanding bytes */
879 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
880 tc->snd_una, tc->snd_una_max);
881 sb->tail = scoreboard_hole_index (sb, last_hole);
882 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
883 sb->high_sacked = tmp.end;
887 /* If we have holes but snd_una_max is beyond the last hole, update
889 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
890 last_hole = scoreboard_last_hole (sb);
891 if (seq_gt (tc->snd_una_max, last_hole->end))
893 if (seq_geq (last_hole->start, sb->high_sacked))
895 last_hole->end = tc->snd_una_max;
897 /* New hole after high sacked block */
898 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
900 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
904 /* Keep track of max byte sacked for when the last hole
906 if (seq_gt (tmp.end, sb->high_sacked))
907 sb->high_sacked = tmp.end;
910 /* Walk the holes with the SACK blocks */
911 hole = pool_elt_at_index (sb->holes, sb->head);
912 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
914 blk = &tc->rcv_opts.sacks[blk_index];
915 if (seq_leq (blk->start, hole->start))
917 /* Block covers hole. Remove hole */
918 if (seq_geq (blk->end, hole->end))
920 next_hole = scoreboard_next_hole (sb, hole);
922 /* Byte accounting: snd_una needs to be advanced */
927 if (seq_lt (ack, next_hole->start))
928 sb->snd_una_adv = next_hole->start - ack;
929 sb->last_bytes_delivered +=
930 next_hole->start - hole->end;
934 ASSERT (seq_geq (sb->high_sacked, ack));
935 sb->snd_una_adv = sb->high_sacked - ack;
936 sb->last_bytes_delivered += sb->high_sacked - hole->end;
940 scoreboard_remove_hole (sb, hole);
943 /* Partial 'head' overlap */
946 if (seq_gt (blk->end, hole->start))
948 hole->start = blk->end;
955 /* Hole must be split */
956 if (seq_lt (blk->end, hole->end))
958 hole_index = scoreboard_hole_index (sb, hole);
959 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
962 /* Pool might've moved */
963 hole = scoreboard_get_hole (sb, hole_index);
964 hole->end = blk->start;
966 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
968 else if (seq_lt (blk->start, hole->end))
970 hole->end = blk->start;
972 hole = scoreboard_next_hole (sb, hole);
976 scoreboard_update_bytes (tc, sb);
977 sb->last_sacked_bytes = sb->sacked_bytes
978 - (old_sacked_bytes - sb->last_bytes_delivered);
979 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
980 ASSERT (sb->sacked_bytes == 0
981 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
982 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
983 - seq_max (tc->snd_una, ack));
984 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
985 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
986 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
990 * Try to update snd_wnd based on feedback received from peer.
992 * If successful, and new window is 'effectively' 0, activate persist
996 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
998 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
999 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1000 if (seq_lt (tc->snd_wl1, seq)
1001 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1003 tc->snd_wnd = snd_wnd;
1006 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1008 if (tc->snd_wnd < tc->snd_mss)
1010 /* Set persist timer if not set and we just got 0 wnd */
1011 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1012 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1013 tcp_persist_timer_set (tc);
1017 tcp_persist_timer_reset (tc);
1018 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
1021 tcp_update_rto (tc);
1028 * Init loss recovery/fast recovery.
1030 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1031 * updated in @ref tcp_cc_handle_event after fast retransmit
1034 tcp_cc_init_congestion (tcp_connection_t * tc)
1036 tcp_fastrecovery_on (tc);
1037 tc->snd_congestion = tc->snd_una_max;
1038 tc->cwnd_acc_bytes = 0;
1039 tc->cc_algo->congestion (tc);
1040 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1044 tcp_cc_recovery_exit (tcp_connection_t * tc)
1047 tcp_update_rto (tc);
1049 tc->snd_nxt = tc->snd_una_max;
1050 tcp_recovery_off (tc);
1051 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1055 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1057 tc->cc_algo->recovered (tc);
1058 tc->snd_rxt_bytes = 0;
1059 tc->rcv_dupacks = 0;
1060 tc->snd_nxt = tc->snd_una_max;
1061 tcp_fastrecovery_off (tc);
1062 tcp_fastrecovery_1_smss_off (tc);
1063 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1067 tcp_cc_congestion_undo (tcp_connection_t * tc)
1069 tc->cwnd = tc->prev_cwnd;
1070 tc->ssthresh = tc->prev_ssthresh;
1071 tc->snd_nxt = tc->snd_una_max;
1072 tc->rcv_dupacks = 0;
1073 if (tcp_in_recovery (tc))
1074 tcp_cc_recovery_exit (tc);
1075 ASSERT (tc->rto_boff == 0);
1076 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1077 /* TODO extend for fastrecovery */
1081 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1083 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1085 && tcp_opts_tstamp (&tc->rcv_opts)
1086 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1090 tcp_cc_recover (tcp_connection_t * tc)
1092 ASSERT (tcp_in_cong_recovery (tc));
1093 if (tcp_cc_is_spurious_retransmit (tc))
1095 tcp_cc_congestion_undo (tc);
1099 if (tcp_in_recovery (tc))
1100 tcp_cc_recovery_exit (tc);
1101 else if (tcp_in_fastrecovery (tc))
1102 tcp_cc_fastrecovery_exit (tc);
1104 ASSERT (tc->rto_boff == 0);
1105 ASSERT (!tcp_in_cong_recovery (tc));
1106 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1111 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1113 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1115 /* Congestion avoidance */
1116 tc->cc_algo->rcv_ack (tc);
1117 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1119 /* If a cumulative ack, make sure dupacks is 0 */
1120 tc->rcv_dupacks = 0;
1122 /* When dupacks hits the threshold we only enter fast retransmit if
1123 * cumulative ack covers more than snd_congestion. Should snd_una
1124 * wrap this test may fail under otherwise valid circumstances.
1125 * Therefore, proactively update snd_congestion when wrap detected. */
1127 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1128 && seq_gt (tc->snd_congestion, tc->snd_una)))
1129 tc->snd_congestion = tc->snd_una - 1;
1133 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1135 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1139 tcp_should_fastrecover (tcp_connection_t * tc)
1141 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1142 || tcp_should_fastrecover_sack (tc));
1146 * One function to rule them all ... and in the darkness bind them
1149 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1153 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1155 if (tc->bytes_acked)
1157 tcp_fast_retransmit (tc);
1161 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1162 * it account for the bytes that left the network.
1164 else if (is_dack && !tcp_in_recovery (tc))
1166 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1167 ASSERT (tc->snd_una != tc->snd_una_max
1168 || tc->sack_sb.last_sacked_bytes);
1172 /* Pure duplicate ack. If some data got acked, it's handled lower */
1173 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1175 ASSERT (tcp_in_fastrecovery (tc));
1176 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1179 else if (tcp_should_fastrecover (tc))
1181 ASSERT (!tcp_in_fastrecovery (tc));
1183 /* If of of the two conditions lower hold, reset dupacks because
1184 * we're probably after timeout (RFC6582 heuristics).
1185 * If Cumulative ack does not cover more than congestion threshold,
1187 * 1) The following doesn't hold: The congestion window is greater
1188 * than SMSS bytes and the difference between highest_ack
1189 * and prev_highest_ack is at most 4*SMSS bytes
1190 * 2) Echoed timestamp in the last non-dup ack does not equal the
1193 if (seq_leq (tc->snd_una, tc->snd_congestion)
1194 && ((!(tc->cwnd > tc->snd_mss
1195 && tc->bytes_acked <= 4 * tc->snd_mss))
1196 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1198 tc->rcv_dupacks = 0;
1202 tcp_cc_init_congestion (tc);
1203 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1205 /* The first segment MUST be retransmitted */
1206 tcp_retransmit_first_unacked (tc);
1208 /* Post retransmit update cwnd to ssthresh and account for the
1209 * three segments that have left the network and should've been
1210 * buffered at the receiver XXX */
1211 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1212 ASSERT (tc->cwnd >= tc->snd_mss);
1214 /* If cwnd allows, send more data */
1215 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1217 scoreboard_init_high_rxt (&tc->sack_sb,
1218 tc->snd_una + tc->snd_mss);
1219 tcp_fast_retransmit_sack (tc);
1223 tcp_fast_retransmit_no_sack (tc);
1227 else if (!tc->bytes_acked
1228 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1230 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1237 if (!tc->bytes_acked)
1241 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1244 * Legitimate ACK. 1) See if we can exit recovery
1246 /* XXX limit this only to first partial ack? */
1247 if (seq_lt (tc->snd_una, tc->snd_congestion))
1248 tcp_retransmit_timer_force_update (tc);
1250 tcp_retransmit_timer_update (tc);
1252 if (seq_geq (tc->snd_una, tc->snd_congestion))
1254 /* If spurious return, we've already updated everything */
1255 if (tcp_cc_recover (tc))
1257 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1261 tc->snd_nxt = tc->snd_una_max;
1263 /* Treat as congestion avoidance ack */
1264 tc->cc_algo->rcv_ack (tc);
1265 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1270 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1273 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1274 * reset dupacks to 0. Also needed if in congestion recovery */
1275 tc->rcv_dupacks = 0;
1277 /* Post RTO timeout don't try anything fancy */
1278 if (tcp_in_recovery (tc))
1280 tc->cc_algo->rcv_ack (tc);
1281 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1282 transport_add_tx_event (&tc->connection);
1286 /* Remove retransmitted bytes that have been delivered */
1287 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1288 >= tc->sack_sb.last_bytes_delivered
1289 || (tc->flags & TCP_CONN_FINSNT));
1291 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1293 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1294 * remove sacked bytes delivered */
1295 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1296 - tc->sack_sb.last_bytes_delivered;
1297 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1298 tc->snd_rxt_bytes -= rxt_delivered;
1302 /* Either all retransmitted holes have been acked, or we're
1303 * "in the blind" and retransmitting segment by segment */
1304 tc->snd_rxt_bytes = 0;
1307 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1310 * Since this was a partial ack, try to retransmit some more data
1312 tcp_fast_retransmit (tc);
1316 * Process incoming ACK
1319 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1320 tcp_header_t * th, u32 * next, u32 * error)
1322 u32 prev_snd_wnd, prev_snd_una;
1325 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1327 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1328 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1330 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1331 * still has the data so accept the ack */
1332 if (tcp_in_recovery (tc)
1333 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1335 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1336 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1337 tc->snd_una_max = tc->snd_nxt;
1341 /* If we have outstanding data and this is within the window, accept it,
1342 * probably retransmit has timed out. Otherwise ACK segment and then
1344 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1346 tcp_make_ack (tc, b);
1347 *next = tcp_next_output (tc->c_is_ip4);
1348 *error = TCP_ERROR_ACK_INVALID;
1349 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1350 vnet_buffer (b)->tcp.ack_number);
1354 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1355 vnet_buffer (b)->tcp.ack_number);
1357 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1358 *error = TCP_ERROR_ACK_FUTURE;
1361 /* If old ACK, probably it's an old dupack */
1362 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1364 *error = TCP_ERROR_ACK_OLD;
1365 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1366 vnet_buffer (b)->tcp.ack_number);
1367 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1368 tcp_cc_handle_event (tc, 1);
1369 /* Don't drop yet */
1374 * Looks okay, process feedback
1377 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1378 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1380 prev_snd_wnd = tc->snd_wnd;
1381 prev_snd_una = tc->snd_una;
1382 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1383 vnet_buffer (b)->tcp.ack_number,
1384 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1385 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1386 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1387 tcp_validate_txf_size (tc, tc->bytes_acked);
1389 if (tc->bytes_acked)
1390 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1392 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1395 * Check if we have congestion event
1398 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1400 tcp_cc_handle_event (tc, is_dack);
1401 if (!tcp_in_cong_recovery (tc))
1403 *error = TCP_ERROR_ACK_DUP;
1404 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1410 * Update congestion control (slow start/congestion avoidance)
1412 tcp_cc_update (tc, b);
1413 *error = TCP_ERROR_ACK_OK;
1418 tcp_sack_vector_is_sane (sack_block_t * sacks)
1421 for (i = 1; i < vec_len (sacks); i++)
1423 if (sacks[i - 1].end == sacks[i].start)
1430 * Build SACK list as per RFC2018.
1432 * Makes sure the first block contains the segment that generated the current
1433 * ACK and the following ones are the ones most recently reported in SACK
1436 * @param tc TCP connection for which the SACK list is updated
1437 * @param start Start sequence number of the newest SACK block
1438 * @param end End sequence of the newest SACK block
1441 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1443 sack_block_t *new_list = 0, *block = 0;
1446 /* If the first segment is ooo add it to the list. Last write might've moved
1447 * rcv_nxt over the first segment. */
1448 if (seq_lt (tc->rcv_nxt, start))
1450 vec_add2 (new_list, block, 1);
1451 block->start = start;
1455 /* Find the blocks still worth keeping. */
1456 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1458 /* Discard if rcv_nxt advanced beyond current block */
1459 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1462 /* Merge or drop if segment overlapped by the new segment */
1463 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1464 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1466 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1467 new_list[0].start = tc->snd_sacks[i].start;
1468 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1469 new_list[0].end = tc->snd_sacks[i].end;
1473 /* Save to new SACK list if we have space. */
1474 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1476 vec_add1 (new_list, tc->snd_sacks[i]);
1480 clib_warning ("sack discarded");
1484 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1486 /* Replace old vector with new one */
1487 vec_free (tc->snd_sacks);
1488 tc->snd_sacks = new_list;
1490 /* Segments should not 'touch' */
1491 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1495 tcp_sack_list_bytes (tcp_connection_t * tc)
1498 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1499 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1503 /** Enqueue data for delivery to application */
1505 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1508 int written, error = TCP_ERROR_ENQUEUED;
1510 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1512 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1513 1 /* queue event */ , 1);
1515 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1517 /* Update rcv_nxt */
1518 if (PREDICT_TRUE (written == data_len))
1520 tc->rcv_nxt += written;
1522 /* If more data written than expected, account for out-of-order bytes. */
1523 else if (written > data_len)
1525 tc->rcv_nxt += written;
1527 /* Send ACK confirming the update */
1528 tc->flags |= TCP_CONN_SNDACK;
1529 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1531 else if (written > 0)
1533 /* We've written something but FIFO is probably full now */
1534 tc->rcv_nxt += written;
1536 /* Depending on how fast the app is, all remaining buffers in burst will
1537 * not be enqueued. Inform peer */
1538 tc->flags |= TCP_CONN_SNDACK;
1540 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1544 tc->flags |= TCP_CONN_SNDACK;
1545 return TCP_ERROR_FIFO_FULL;
1548 /* Update SACK list if need be */
1549 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1551 /* Remove SACK blocks that have been delivered */
1552 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1558 /** Enqueue out-of-order data */
1560 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1563 stream_session_t *s0;
1566 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1569 /* Enqueue out-of-order data with relative offset */
1570 rv = session_enqueue_stream_connection (&tc->connection, b,
1571 vnet_buffer (b)->tcp.seq_number -
1572 tc->rcv_nxt, 0 /* queue event */ ,
1575 /* Nothing written */
1578 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1579 return TCP_ERROR_FIFO_FULL;
1582 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1584 /* Update SACK list if in use */
1585 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1587 ooo_segment_t *newest;
1590 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1592 /* Get the newest segment from the fifo */
1593 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1596 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1597 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1598 start = tc->rcv_nxt + offset;
1599 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1600 tcp_update_sack_list (tc, start, end);
1601 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1602 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1606 return TCP_ERROR_ENQUEUED_OOO;
1610 * Check if ACK could be delayed. If ack can be delayed, it should return
1611 * true for a full frame. If we're always acking return 0.
1614 tcp_can_delack (tcp_connection_t * tc)
1616 /* Send ack if ... */
1618 /* just sent a rcv wnd 0 */
1619 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1620 /* constrained to send ack */
1621 || (tc->flags & TCP_CONN_SNDACK) != 0
1622 /* we're almost out of tx wnd */
1623 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1630 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1632 u32 discard, first = b->current_length;
1633 vlib_main_t *vm = vlib_get_main ();
1635 /* Handle multi-buffer segments */
1636 if (n_bytes_to_drop > b->current_length)
1638 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1642 discard = clib_min (n_bytes_to_drop, b->current_length);
1643 vlib_buffer_advance (b, discard);
1644 b = vlib_get_buffer (vm, b->next_buffer);
1645 n_bytes_to_drop -= discard;
1647 while (n_bytes_to_drop);
1648 if (n_bytes_to_drop > first)
1649 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1652 vlib_buffer_advance (b, n_bytes_to_drop);
1653 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1658 * Receive buffer for connection and handle acks
1660 * It handles both in order or out-of-order data.
1663 tcp_segment_rcv (tcp_connection_t * tc, vlib_buffer_t * b, u32 * next0)
1665 u32 error, n_bytes_to_drop, n_data_bytes;
1667 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1668 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1669 ASSERT (n_data_bytes);
1671 /* Handle out-of-order data */
1672 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1674 /* Old sequence numbers allowed through because they overlapped
1676 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1678 /* Completely in the past (possible retransmit). Ack
1679 * retransmissions since we may not have any data to send */
1680 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1682 tcp_make_ack (tc, b);
1683 error = TCP_ERROR_SEGMENT_OLD;
1684 *next0 = tcp_next_output (tc->c_is_ip4);
1688 /* Chop off the bytes in the past and see if what is left
1689 * can be enqueued in order */
1690 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1691 n_data_bytes -= n_bytes_to_drop;
1692 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1693 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1695 error = TCP_ERROR_SEGMENT_OLD;
1696 *next0 = tcp_next_drop (tc->c_is_ip4);
1702 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1703 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1704 *next0 = tcp_next_output (tc->c_is_ip4);
1705 tcp_make_ack (tc, b);
1706 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1707 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1713 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1714 * segments can be enqueued after fifo tail offset changes. */
1715 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1716 if (tcp_can_delack (tc))
1718 *next0 = tcp_next_drop (tc->c_is_ip4);
1719 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1720 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1724 *next0 = tcp_next_output (tc->c_is_ip4);
1725 tcp_make_ack (tc, b);
1733 tcp_header_t tcp_header;
1734 tcp_connection_t tcp_connection;
1738 format_tcp_rx_trace (u8 * s, va_list * args)
1740 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1741 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1742 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1743 u32 indent = format_get_indent (s);
1745 s = format (s, "%U\n%U%U",
1746 format_tcp_header, &t->tcp_header, 128,
1747 format_white_space, indent,
1748 format_tcp_connection, &t->tcp_connection, 1);
1754 format_tcp_rx_trace_short (u8 * s, va_list * args)
1756 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1757 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1758 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1760 s = format (s, "%d -> %d (%U)",
1761 clib_net_to_host_u16 (t->tcp_header.dst_port),
1762 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1763 t->tcp_connection.state);
1769 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1770 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1774 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1778 th0 = tcp_buffer_hdr (b0);
1780 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1784 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
1785 vlib_frame_t * frame, u8 is_ip4)
1789 n_left = frame->n_vectors;
1790 from = vlib_frame_vector_args (frame);
1794 tcp_connection_t *tc0;
1801 b0 = vlib_get_buffer (vm, bi0);
1803 if (b0->flags & VLIB_BUFFER_IS_TRACED)
1805 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1806 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1808 th0 = tcp_buffer_hdr (b0);
1809 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1818 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1819 u8 is_ip4, u32 evt, u32 val)
1822 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1824 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1827 #define tcp_maybe_inc_counter(node_id, err, count) \
1829 if (next0 != tcp_next_drop (is_ip4)) \
1830 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1831 tcp6_##node_id##_node.index, is_ip4, err, \
1834 #define tcp_inc_counter(node_id, err, count) \
1835 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1836 tcp6_##node_id##_node.index, is_ip4, \
1838 #define tcp_maybe_inc_err_counter(cnts, err) \
1840 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
1842 #define tcp_inc_err_counter(cnts, err, val) \
1846 #define tcp_store_err_counters(node_id, cnts) \
1849 for (i = 0; i < TCP_N_ERROR; i++) \
1851 tcp_inc_counter(node_id, i, cnts[i]); \
1856 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1857 vlib_frame_t * frame, int is_ip4)
1859 u32 thread_index = vm->thread_index, errors = 0;
1860 u32 n_left_from, next_index, *from, *to_next;
1861 u16 err_counters[TCP_N_ERROR] = { 0 };
1864 if (node->flags & VLIB_NODE_FLAG_TRACE)
1865 tcp_established_trace_frame (vm, node, frame, is_ip4);
1867 from = vlib_frame_vector_args (frame);
1868 n_left_from = frame->n_vectors;
1869 next_index = node->cached_next_index;
1871 while (n_left_from > 0)
1875 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1876 while (n_left_from > 0 && n_left_to_next > 0)
1880 tcp_header_t *th0 = 0;
1881 tcp_connection_t *tc0;
1882 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ACK_OK;
1884 if (n_left_from > 1)
1887 pb = vlib_get_buffer (vm, from[1]);
1888 vlib_prefetch_buffer_header (pb, LOAD);
1889 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
1897 n_left_to_next -= 1;
1899 b0 = vlib_get_buffer (vm, bi0);
1900 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1903 if (PREDICT_FALSE (tc0 == 0))
1905 error0 = TCP_ERROR_INVALID_CONNECTION;
1909 th0 = tcp_buffer_hdr (b0);
1910 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1911 * dangling reference. */
1912 is_fin = tcp_is_fin (th0);
1914 /* SYNs, FINs and data consume sequence numbers */
1915 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1916 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1918 /* TODO header prediction fast path */
1920 /* 1-4: check SEQ, RST, SYN */
1921 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0,
1924 tcp_maybe_inc_err_counter (err_counters, error0);
1925 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
1929 /* 5: check the ACK field */
1930 if (PREDICT_FALSE (tcp_rcv_ack (tc0, b0, th0, &next0, &error0)))
1932 tcp_maybe_inc_err_counter (err_counters, error0);
1936 /* 6: check the URG bit TODO */
1938 /* 7: process the segment text */
1939 if (vnet_buffer (b0)->tcp.data_len)
1941 error0 = tcp_segment_rcv (tc0, b0, &next0);
1942 tcp_maybe_inc_err_counter (err_counters, error0);
1945 /* 8: check the FIN bit */
1946 if (PREDICT_FALSE (is_fin))
1948 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1949 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1950 /* Account for the FIN if nothing else was received */
1951 if (vnet_buffer (b0)->tcp.data_len == 0)
1953 tcp_make_ack (tc0, b0);
1954 next0 = tcp_next_output (tc0->c_is_ip4);
1955 tc0->state = TCP_STATE_CLOSE_WAIT;
1956 stream_session_disconnect_notify (&tc0->connection);
1957 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1958 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1959 tcp_inc_err_counter (err_counters, TCP_ERROR_FIN_RCVD, 1);
1963 b0->error = node->errors[error0];
1964 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1965 n_left_to_next, bi0, next0);
1968 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1971 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
1973 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
1974 tcp_store_err_counters (established, err_counters);
1975 tcp_flush_frame_to_output (vm, thread_index, is_ip4);
1977 return frame->n_vectors;
1981 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1982 vlib_frame_t * from_frame)
1984 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1988 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1989 vlib_frame_t * from_frame)
1991 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1995 VLIB_REGISTER_NODE (tcp4_established_node) =
1997 .function = tcp4_established,
1998 .name = "tcp4-established",
1999 /* Takes a vector of packets. */
2000 .vector_size = sizeof (u32),
2001 .n_errors = TCP_N_ERROR,
2002 .error_strings = tcp_error_strings,
2003 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2006 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2007 foreach_tcp_state_next
2010 .format_trace = format_tcp_rx_trace_short,
2014 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2017 VLIB_REGISTER_NODE (tcp6_established_node) =
2019 .function = tcp6_established,
2020 .name = "tcp6-established",
2021 /* Takes a vector of packets. */
2022 .vector_size = sizeof (u32),
2023 .n_errors = TCP_N_ERROR,
2024 .error_strings = tcp_error_strings,
2025 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2028 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2029 foreach_tcp_state_next
2032 .format_trace = format_tcp_rx_trace_short,
2037 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2039 vlib_node_registration_t tcp4_syn_sent_node;
2040 vlib_node_registration_t tcp6_syn_sent_node;
2043 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2045 transport_connection_t *tmp = 0;
2052 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2055 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2056 && (tc->state == TCP_STATE_LISTEN
2057 || tc->c_rmt_port == hdr->src_port));
2061 handle = session_lookup_half_open_handle (&tc->connection);
2062 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2063 tc->c_proto, tc->c_is_ip4);
2067 if (tmp->lcl_port == hdr->dst_port
2068 && tmp->rmt_port == hdr->src_port)
2070 TCP_DBG ("half-open is valid!");
2078 * Lookup transport connection
2080 static tcp_connection_t *
2081 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2085 transport_connection_t *tconn;
2086 tcp_connection_t *tc;
2091 ip4 = vlib_buffer_get_current (b);
2092 tcp = ip4_next_header (ip4);
2093 tconn = session_lookup_connection_wt4 (fib_index,
2098 TRANSPORT_PROTO_TCP,
2099 thread_index, &is_filtered);
2100 tc = tcp_get_connection_from_transport (tconn);
2101 ASSERT (tcp_lookup_is_valid (tc, tcp));
2106 ip6 = vlib_buffer_get_current (b);
2107 tcp = ip6_next_header (ip6);
2108 tconn = session_lookup_connection_wt6 (fib_index,
2113 TRANSPORT_PROTO_TCP,
2114 thread_index, &is_filtered);
2115 tc = tcp_get_connection_from_transport (tconn);
2116 ASSERT (tcp_lookup_is_valid (tc, tcp));
2122 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2123 vlib_frame_t * from_frame, int is_ip4)
2125 tcp_main_t *tm = vnet_get_tcp_main ();
2126 u32 n_left_from, next_index, *from, *to_next;
2127 u32 my_thread_index = vm->thread_index, errors = 0;
2129 from = vlib_frame_vector_args (from_frame);
2130 n_left_from = from_frame->n_vectors;
2132 next_index = node->cached_next_index;
2134 while (n_left_from > 0)
2138 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2140 while (n_left_from > 0 && n_left_to_next > 0)
2142 u32 bi0, ack0, seq0;
2145 tcp_header_t *tcp0 = 0;
2146 tcp_connection_t *tc0;
2147 tcp_connection_t *new_tc0;
2148 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
2155 n_left_to_next -= 1;
2157 b0 = vlib_get_buffer (vm, bi0);
2159 tcp_half_open_connection_get (vnet_buffer (b0)->
2160 tcp.connection_index);
2161 if (PREDICT_FALSE (tc0 == 0))
2163 error0 = TCP_ERROR_INVALID_CONNECTION;
2167 /* Half-open completed recently but the connection was't removed
2168 * yet by the owning thread */
2169 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2171 /* Make sure the connection actually exists */
2172 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2173 my_thread_index, is_ip4));
2177 ack0 = vnet_buffer (b0)->tcp.ack_number;
2178 seq0 = vnet_buffer (b0)->tcp.seq_number;
2179 tcp0 = tcp_buffer_hdr (b0);
2181 /* Crude check to see if the connection handle does not match
2182 * the packet. Probably connection just switched to established */
2183 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2184 || tcp0->src_port != tc0->c_rmt_port))
2188 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
2191 /* SYNs, FINs and data consume sequence numbers */
2192 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
2193 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
2196 * 1. check the ACK bit
2200 * If the ACK bit is set
2201 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2202 * the RST bit is set, if so drop the segment and return)
2203 * <SEQ=SEG.ACK><CTL=RST>
2204 * and discard the segment. Return.
2205 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2209 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2211 clib_warning ("ack not in rcv wnd");
2212 if (!tcp_rst (tcp0))
2213 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2217 /* Make sure ACK is valid */
2218 if (seq_gt (tc0->snd_una, ack0))
2220 clib_warning ("ack invalid");
2226 * 2. check the RST bit
2231 /* If ACK is acceptable, signal client that peer is not
2232 * willing to accept connection and drop connection*/
2234 tcp_connection_reset (tc0);
2239 * 3. check the security and precedence (skipped)
2243 * 4. check the SYN bit
2246 /* No SYN flag. Drop. */
2247 if (!tcp_syn (tcp0))
2249 clib_warning ("not synack");
2254 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2256 clib_warning ("options parse fail");
2260 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2261 * current thread pool. */
2262 pool_get (tm->connections[my_thread_index], new_tc0);
2263 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2264 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2265 new_tc0->c_thread_index = my_thread_index;
2266 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2267 new_tc0->irs = seq0;
2268 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2269 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2270 TCP_TIMER_HANDLE_INVALID;
2271 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2273 /* If this is not the owning thread, wait for syn retransmit to
2274 * expire and cleanup then */
2275 if (tcp_half_open_connection_cleanup (tc0))
2276 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2278 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2280 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2281 new_tc0->tsval_recent_age = tcp_time_now ();
2284 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2285 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2287 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2288 << new_tc0->snd_wscale;
2289 new_tc0->snd_wl1 = seq0;
2290 new_tc0->snd_wl2 = ack0;
2292 tcp_connection_init_vars (new_tc0);
2294 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2295 if (PREDICT_TRUE (tcp_ack (tcp0)))
2297 /* Our SYN is ACKed: we have iss < ack = snd_una */
2299 /* TODO Dequeue acknowledged segments if we support Fast Open */
2300 new_tc0->snd_una = ack0;
2301 new_tc0->state = TCP_STATE_ESTABLISHED;
2303 /* Make sure las is initialized for the wnd computation */
2304 new_tc0->rcv_las = new_tc0->rcv_nxt;
2306 /* Notify app that we have connection. If session layer can't
2307 * allocate session send reset */
2308 if (session_stream_connect_notify (&new_tc0->connection, 0))
2310 clib_warning ("connect notify fail");
2311 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2312 tcp_connection_cleanup (new_tc0);
2316 /* Make sure after data segment processing ACK is sent */
2317 new_tc0->flags |= TCP_CONN_SNDACK;
2319 /* Update rtt with the syn-ack sample */
2320 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2321 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2323 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2326 new_tc0->state = TCP_STATE_SYN_RCVD;
2328 /* Notify app that we have connection */
2329 if (session_stream_connect_notify (&new_tc0->connection, 0))
2331 tcp_connection_cleanup (new_tc0);
2332 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2333 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2338 tcp_init_snd_vars (tc0);
2339 tcp_make_synack (new_tc0, b0);
2340 next0 = tcp_next_output (is_ip4);
2345 /* Read data, if any */
2346 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2348 clib_warning ("rcvd data in syn-sent");
2349 error0 = tcp_segment_rcv (new_tc0, b0, &next0);
2350 if (error0 == TCP_ERROR_ACK_OK)
2351 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2352 tcp_maybe_inc_counter (syn_sent, error0, 1);
2356 tcp_make_ack (new_tc0, b0);
2357 next0 = tcp_next_output (new_tc0->c_is_ip4);
2362 b0->error = error0 ? node->errors[error0] : 0;
2364 ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2366 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2367 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2368 clib_memcpy (&t0->tcp_connection, tc0,
2369 sizeof (t0->tcp_connection));
2372 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2373 n_left_to_next, bi0, next0);
2376 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2379 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2381 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2382 return from_frame->n_vectors;
2386 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2387 vlib_frame_t * from_frame)
2389 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2393 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2394 vlib_frame_t * from_frame)
2396 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2400 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2402 .function = tcp4_syn_sent,
2403 .name = "tcp4-syn-sent",
2404 /* Takes a vector of packets. */
2405 .vector_size = sizeof (u32),
2406 .n_errors = TCP_N_ERROR,
2407 .error_strings = tcp_error_strings,
2408 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2411 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2412 foreach_tcp_state_next
2415 .format_trace = format_tcp_rx_trace_short,
2419 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2422 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2424 .function = tcp6_syn_sent_rcv,
2425 .name = "tcp6-syn-sent",
2426 /* Takes a vector of packets. */
2427 .vector_size = sizeof (u32),
2428 .n_errors = TCP_N_ERROR,
2429 .error_strings = tcp_error_strings,
2430 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2433 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2434 foreach_tcp_state_next
2437 .format_trace = format_tcp_rx_trace_short,
2441 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2443 vlib_node_registration_t tcp4_rcv_process_node;
2444 vlib_node_registration_t tcp6_rcv_process_node;
2447 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2448 * as per RFC793 p. 64
2451 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2452 vlib_frame_t * from_frame, int is_ip4)
2454 u32 n_left_from, next_index, *from, *to_next, n_fins = 0;
2455 u32 my_thread_index = vm->thread_index, errors = 0;
2457 from = vlib_frame_vector_args (from_frame);
2458 n_left_from = from_frame->n_vectors;
2459 next_index = node->cached_next_index;
2461 while (n_left_from > 0)
2465 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2467 while (n_left_from > 0 && n_left_to_next > 0)
2471 tcp_header_t *tcp0 = 0;
2472 tcp_connection_t *tc0;
2473 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_NONE;
2481 n_left_to_next -= 1;
2483 b0 = vlib_get_buffer (vm, bi0);
2484 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2486 if (PREDICT_FALSE (tc0 == 0))
2488 error0 = TCP_ERROR_INVALID_CONNECTION;
2492 tcp0 = tcp_buffer_hdr (b0);
2493 is_fin0 = tcp_is_fin (tcp0);
2495 /* SYNs, FINs and data consume sequence numbers */
2496 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2497 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2501 tcp_connection_t *tmp;
2502 tmp = tcp_lookup_connection (tc0->c_fib_index, b0,
2503 my_thread_index, is_ip4);
2504 if (tmp->state != tc0->state)
2506 clib_warning ("state changed");
2512 * Special treatment for CLOSED
2514 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2516 error0 = TCP_ERROR_CONNECTION_CLOSED;
2521 * For all other states (except LISTEN)
2524 /* 1-4: check SEQ, RST, SYN */
2525 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2528 tcp_maybe_inc_counter (rcv_process, error0, 1);
2532 /* 5: check the ACK field */
2535 case TCP_STATE_SYN_RCVD:
2537 * If the segment acknowledgment is not acceptable, form a
2539 * <SEQ=SEG.ACK><CTL=RST>
2542 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2544 TCP_DBG ("connection not accepted");
2545 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2546 error0 = TCP_ERROR_ACK_INVALID;
2550 /* Update rtt and rto */
2551 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2553 /* Switch state to ESTABLISHED */
2554 tc0->state = TCP_STATE_ESTABLISHED;
2555 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2557 /* Initialize session variables */
2558 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2559 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2560 << tc0->rcv_opts.wscale;
2561 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2562 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2564 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2565 tcp_retransmit_timer_reset (tc0);
2566 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2567 stream_session_accept_notify (&tc0->connection);
2568 error0 = TCP_ERROR_ACK_OK;
2570 case TCP_STATE_ESTABLISHED:
2571 /* We can get packets in established state here because they
2572 * were enqueued before state change */
2573 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2575 tcp_maybe_inc_counter (rcv_process, error0, 1);
2580 case TCP_STATE_FIN_WAIT_1:
2581 /* In addition to the processing for the ESTABLISHED state, if
2582 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2583 * continue processing in that state. */
2584 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2586 tcp_maybe_inc_counter (rcv_process, error0, 1);
2590 /* Still have to send the FIN */
2591 if (tc0->flags & TCP_CONN_FINPNDG)
2593 /* TX fifo finally drained */
2594 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2597 /* If FIN is ACKed */
2598 else if (tc0->snd_una == tc0->snd_una_max)
2600 tc0->state = TCP_STATE_FIN_WAIT_2;
2601 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2603 /* Stop all retransmit timers because we have nothing more
2604 * to send. Enable waitclose though because we're willing to
2605 * wait for peer's FIN but not indefinitely. */
2606 tcp_connection_timers_reset (tc0);
2607 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2610 case TCP_STATE_FIN_WAIT_2:
2611 /* In addition to the processing for the ESTABLISHED state, if
2612 * the retransmission queue is empty, the user's CLOSE can be
2613 * acknowledged ("ok") but do not delete the TCB. */
2614 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2616 tcp_maybe_inc_counter (rcv_process, error0, 1);
2620 case TCP_STATE_CLOSE_WAIT:
2621 /* Do the same processing as for the ESTABLISHED state. */
2622 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2624 tcp_maybe_inc_counter (rcv_process, error0, 1);
2627 if (tc0->flags & TCP_CONN_FINPNDG)
2629 /* TX fifo finally drained */
2630 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2633 tcp_connection_timers_reset (tc0);
2634 tc0->state = TCP_STATE_LAST_ACK;
2635 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2640 case TCP_STATE_CLOSING:
2641 /* In addition to the processing for the ESTABLISHED state, if
2642 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2643 * otherwise ignore the segment. */
2644 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2646 tcp_maybe_inc_counter (rcv_process, error0, 1);
2650 tc0->state = TCP_STATE_TIME_WAIT;
2651 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2652 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2656 case TCP_STATE_LAST_ACK:
2657 /* The only thing that [should] arrive in this state is an
2658 * acknowledgment of our FIN. If our FIN is now acknowledged,
2659 * delete the TCB, enter the CLOSED state, and return. */
2661 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2663 error0 = TCP_ERROR_ACK_INVALID;
2666 error0 = TCP_ERROR_ACK_OK;
2667 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2668 /* Apparently our ACK for the peer's FIN was lost */
2669 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2675 tc0->state = TCP_STATE_CLOSED;
2676 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2677 /* Delete the connection/session since the pipes should be
2679 tcp_connection_del (tc0);
2684 case TCP_STATE_TIME_WAIT:
2685 /* The only thing that can arrive in this state is a
2686 * retransmission of the remote FIN. Acknowledge it, and restart
2687 * the 2 MSL timeout. */
2689 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2691 tcp_maybe_inc_counter (rcv_process, error0, 1);
2695 tcp_make_ack (tc0, b0);
2696 next0 = tcp_next_output (is_ip4);
2697 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2705 /* 6: check the URG bit TODO */
2707 /* 7: process the segment text */
2710 case TCP_STATE_ESTABLISHED:
2711 case TCP_STATE_FIN_WAIT_1:
2712 case TCP_STATE_FIN_WAIT_2:
2713 if (vnet_buffer (b0)->tcp.data_len)
2715 error0 = tcp_segment_rcv (tc0, b0, &next0);
2716 tcp_maybe_inc_counter (rcv_process, error0, 1);
2721 case TCP_STATE_CLOSE_WAIT:
2722 case TCP_STATE_CLOSING:
2723 case TCP_STATE_LAST_ACK:
2724 case TCP_STATE_TIME_WAIT:
2725 /* This should not occur, since a FIN has been received from the
2726 * remote side. Ignore the segment text. */
2730 /* 8: check the FIN bit */
2736 case TCP_STATE_ESTABLISHED:
2737 case TCP_STATE_SYN_RCVD:
2738 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2739 tcp_connection_timers_reset (tc0);
2740 tcp_make_fin (tc0, b0);
2742 tc0->snd_una_max = tc0->snd_nxt;
2743 tcp_retransmit_timer_set (tc0);
2744 next0 = tcp_next_output (tc0->c_is_ip4);
2745 stream_session_disconnect_notify (&tc0->connection);
2746 tc0->state = TCP_STATE_CLOSE_WAIT;
2747 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2749 case TCP_STATE_CLOSE_WAIT:
2750 case TCP_STATE_CLOSING:
2751 case TCP_STATE_LAST_ACK:
2754 case TCP_STATE_FIN_WAIT_1:
2755 tc0->state = TCP_STATE_CLOSING;
2756 tcp_make_ack (tc0, b0);
2757 next0 = tcp_next_output (is_ip4);
2758 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2759 /* Wait for ACK but not forever */
2760 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2762 case TCP_STATE_FIN_WAIT_2:
2763 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2764 tc0->state = TCP_STATE_TIME_WAIT;
2765 tcp_connection_timers_reset (tc0);
2766 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2767 tcp_make_ack (tc0, b0);
2768 next0 = tcp_next_output (is_ip4);
2769 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2771 case TCP_STATE_TIME_WAIT:
2772 /* Remain in the TIME-WAIT state. Restart the time-wait
2775 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2778 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2782 b0->error = error0 ? node->errors[error0] : 0;
2784 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2786 tcp_rx_trace_t *t0 =
2787 vlib_add_trace (vm, node, b0, sizeof (*t0));
2788 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2791 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2792 n_left_to_next, bi0, next0);
2795 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2798 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2800 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2801 tcp_inc_counter (rcv_process, TCP_ERROR_FIN_RCVD, n_fins);
2802 return from_frame->n_vectors;
2806 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2807 vlib_frame_t * from_frame)
2809 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2813 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2814 vlib_frame_t * from_frame)
2816 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2820 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2822 .function = tcp4_rcv_process,
2823 .name = "tcp4-rcv-process",
2824 /* Takes a vector of packets. */
2825 .vector_size = sizeof (u32),
2826 .n_errors = TCP_N_ERROR,
2827 .error_strings = tcp_error_strings,
2828 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2831 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2832 foreach_tcp_state_next
2835 .format_trace = format_tcp_rx_trace_short,
2839 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2842 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2844 .function = tcp6_rcv_process,
2845 .name = "tcp6-rcv-process",
2846 /* Takes a vector of packets. */
2847 .vector_size = sizeof (u32),
2848 .n_errors = TCP_N_ERROR,
2849 .error_strings = tcp_error_strings,
2850 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2853 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2854 foreach_tcp_state_next
2857 .format_trace = format_tcp_rx_trace_short,
2861 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2863 vlib_node_registration_t tcp4_listen_node;
2864 vlib_node_registration_t tcp6_listen_node;
2867 * LISTEN state processing as per RFC 793 p. 65
2870 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2871 vlib_frame_t * from_frame, int is_ip4)
2873 u32 n_left_from, next_index, *from, *to_next, n_syns = 0;
2874 u32 my_thread_index = vm->thread_index;
2876 from = vlib_frame_vector_args (from_frame);
2877 n_left_from = from_frame->n_vectors;
2879 next_index = node->cached_next_index;
2881 while (n_left_from > 0)
2885 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2887 while (n_left_from > 0 && n_left_to_next > 0)
2892 tcp_header_t *th0 = 0;
2893 tcp_connection_t *lc0;
2896 tcp_connection_t *child0;
2897 u32 error0 = TCP_ERROR_NONE, next0 = tcp_next_drop (is_ip4);
2904 n_left_to_next -= 1;
2906 b0 = vlib_get_buffer (vm, bi0);
2907 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2911 ip40 = vlib_buffer_get_current (b0);
2912 th0 = ip4_next_header (ip40);
2916 ip60 = vlib_buffer_get_current (b0);
2917 th0 = ip6_next_header (ip60);
2920 /* Create child session. For syn-flood protection use filter */
2922 /* 1. first check for an RST: handled in dispatch */
2923 /* if (tcp_rst (th0))
2926 /* 2. second check for an ACK: handled in dispatch */
2927 /* if (tcp_ack (th0))
2929 tcp_send_reset (b0, is_ip4);
2933 /* 3. check for a SYN (did that already) */
2935 /* Make sure connection wasn't just created */
2936 child0 = tcp_lookup_connection (lc0->c_fib_index, b0,
2937 my_thread_index, is_ip4);
2938 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
2940 error0 = TCP_ERROR_CREATE_EXISTS;
2944 /* Create child session and send SYN-ACK */
2945 child0 = tcp_connection_new (my_thread_index);
2946 child0->c_lcl_port = th0->dst_port;
2947 child0->c_rmt_port = th0->src_port;
2948 child0->c_is_ip4 = is_ip4;
2949 child0->state = TCP_STATE_SYN_RCVD;
2950 child0->c_fib_index = lc0->c_fib_index;
2954 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2955 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2959 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2960 sizeof (ip6_address_t));
2961 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2962 sizeof (ip6_address_t));
2965 if (tcp_options_parse (th0, &child0->rcv_opts))
2967 clib_warning ("options parse fail");
2971 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2972 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2973 child0->rcv_las = child0->rcv_nxt;
2974 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2976 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2977 * segments are used to initialize PAWS. */
2978 if (tcp_opts_tstamp (&child0->rcv_opts))
2980 child0->tsval_recent = child0->rcv_opts.tsval;
2981 child0->tsval_recent_age = tcp_time_now ();
2984 if (tcp_opts_wscale (&child0->rcv_opts))
2985 child0->snd_wscale = child0->rcv_opts.wscale;
2987 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2988 << child0->snd_wscale;
2989 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2990 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2992 tcp_connection_init_vars (child0);
2993 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
2995 if (stream_session_accept (&child0->connection, lc0->c_s_index,
2998 clib_warning ("session accept fail");
2999 tcp_connection_cleanup (child0);
3000 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3004 /* Reuse buffer to make syn-ack and send */
3005 tcp_make_synack (child0, b0);
3006 next0 = tcp_next_output (is_ip4);
3007 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3010 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3012 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3013 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3014 clib_memcpy (&t0->tcp_connection, lc0,
3015 sizeof (t0->tcp_connection));
3018 n_syns += (error0 == TCP_ERROR_NONE);
3019 b0->error = node->errors[error0];
3021 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
3022 n_left_to_next, bi0, next0);
3025 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3028 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3029 return from_frame->n_vectors;
3033 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3034 vlib_frame_t * from_frame)
3036 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3040 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3041 vlib_frame_t * from_frame)
3043 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3047 VLIB_REGISTER_NODE (tcp4_listen_node) =
3049 .function = tcp4_listen,
3050 .name = "tcp4-listen",
3051 /* Takes a vector of packets. */
3052 .vector_size = sizeof (u32),
3053 .n_errors = TCP_N_ERROR,
3054 .error_strings = tcp_error_strings,
3055 .n_next_nodes = TCP_LISTEN_N_NEXT,
3058 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3059 foreach_tcp_state_next
3062 .format_trace = format_tcp_rx_trace_short,
3066 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3069 VLIB_REGISTER_NODE (tcp6_listen_node) =
3071 .function = tcp6_listen,
3072 .name = "tcp6-listen",
3073 /* Takes a vector of packets. */
3074 .vector_size = sizeof (u32),
3075 .n_errors = TCP_N_ERROR,
3076 .error_strings = tcp_error_strings,
3077 .n_next_nodes = TCP_LISTEN_N_NEXT,
3080 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3081 foreach_tcp_state_next
3084 .format_trace = format_tcp_rx_trace_short,
3088 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3090 vlib_node_registration_t tcp4_input_node;
3091 vlib_node_registration_t tcp6_input_node;
3093 typedef enum _tcp_input_next
3095 TCP_INPUT_NEXT_DROP,
3096 TCP_INPUT_NEXT_LISTEN,
3097 TCP_INPUT_NEXT_RCV_PROCESS,
3098 TCP_INPUT_NEXT_SYN_SENT,
3099 TCP_INPUT_NEXT_ESTABLISHED,
3100 TCP_INPUT_NEXT_RESET,
3101 TCP_INPUT_NEXT_PUNT,
3105 #define foreach_tcp4_input_next \
3106 _ (DROP, "ip4-drop") \
3107 _ (LISTEN, "tcp4-listen") \
3108 _ (RCV_PROCESS, "tcp4-rcv-process") \
3109 _ (SYN_SENT, "tcp4-syn-sent") \
3110 _ (ESTABLISHED, "tcp4-established") \
3111 _ (RESET, "tcp4-reset") \
3112 _ (PUNT, "ip4-punt")
3114 #define foreach_tcp6_input_next \
3115 _ (DROP, "ip6-drop") \
3116 _ (LISTEN, "tcp6-listen") \
3117 _ (RCV_PROCESS, "tcp6-rcv-process") \
3118 _ (SYN_SENT, "tcp6-syn-sent") \
3119 _ (ESTABLISHED, "tcp6-established") \
3120 _ (RESET, "tcp6-reset") \
3121 _ (PUNT, "ip6-punt")
3123 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3126 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3127 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3129 tcp_connection_t *tc;
3134 for (i = 0; i < n_bufs; i++)
3136 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3138 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3139 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3141 tcp = vlib_buffer_get_current (bs[i]);
3142 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3148 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3150 if (*error == TCP_ERROR_FILTERED)
3152 *next = TCP_INPUT_NEXT_DROP;
3154 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3156 *next = TCP_INPUT_NEXT_PUNT;
3157 *error = TCP_ERROR_PUNT;
3161 *next = TCP_INPUT_NEXT_RESET;
3162 *error = TCP_ERROR_NO_LISTENER;
3166 static inline tcp_connection_t *
3167 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3170 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3171 int n_advance_bytes, n_data_bytes;
3172 transport_connection_t *tc;
3178 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3179 tcp = ip4_next_header (ip4);
3180 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3181 n_advance_bytes = (ip4_header_bytes (ip4) + tcp_header_bytes (tcp));
3182 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3184 /* Length check. Checksum computed by ipx_local no need to compute again */
3185 if (PREDICT_FALSE (n_advance_bytes < 0))
3187 *error = TCP_ERROR_LENGTH;
3191 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3192 &ip4->src_address, tcp->dst_port,
3193 tcp->src_port, TRANSPORT_PROTO_TCP,
3194 thread_index, &is_filtered);
3198 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3199 tcp = ip6_next_header (ip6);
3200 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3201 n_advance_bytes = tcp_header_bytes (tcp);
3202 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3204 n_advance_bytes += sizeof (ip6[0]);
3206 if (PREDICT_FALSE (n_advance_bytes < 0))
3208 *error = TCP_ERROR_LENGTH;
3212 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3213 &ip6->src_address, tcp->dst_port,
3214 tcp->src_port, TRANSPORT_PROTO_TCP,
3215 thread_index, &is_filtered);
3218 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3219 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3220 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3221 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3222 vnet_buffer (b)->tcp.flags = 0;
3224 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3226 return tcp_get_connection_from_transport (tc);
3230 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3231 vlib_buffer_t * b, u16 * next, u32 * error)
3236 tcp = tcp_buffer_hdr (b);
3237 flags = tcp->flags & filter_flags;
3238 *next = tm->dispatch_table[tc->state][flags].next;
3239 *error = tm->dispatch_table[tc->state][flags].error;
3241 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3242 || *next == TCP_INPUT_NEXT_RESET))
3244 /* Overload tcp flags to store state */
3245 tcp_state_t state = tc->state;
3246 vnet_buffer (b)->tcp.flags = tc->state;
3248 if (*error == TCP_ERROR_DISPATCH)
3249 clib_warning ("disp error state %U flags %U", format_tcp_state,
3250 state, format_tcp_flags, (int) flags);
3255 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3256 vlib_frame_t * frame, int is_ip4)
3258 u32 n_left_from, *from, thread_index = vm->thread_index;
3259 tcp_main_t *tm = vnet_get_tcp_main ();
3260 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3261 u16 nexts[VLIB_FRAME_SIZE], *next;
3263 tcp_set_time_now (thread_index);
3265 from = vlib_frame_vector_args (frame);
3266 n_left_from = frame->n_vectors;
3267 vlib_get_buffers (vm, from, bufs, n_left_from);
3272 while (n_left_from >= 4)
3274 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3275 tcp_connection_t *tc0, *tc1;
3278 vlib_prefetch_buffer_header (b[2], STORE);
3279 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3281 vlib_prefetch_buffer_header (b[3], STORE);
3282 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3285 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3287 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3288 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3290 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3292 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3293 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3295 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3296 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3298 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3299 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3303 if (PREDICT_TRUE (tc0 != 0))
3305 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3306 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3307 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3310 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3312 if (PREDICT_TRUE (tc1 != 0))
3314 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3315 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3316 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3319 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3326 while (n_left_from > 0)
3328 tcp_connection_t *tc0;
3329 u32 error0 = TCP_ERROR_NO_LISTENER;
3331 if (n_left_from > 1)
3333 vlib_prefetch_buffer_header (b[1], STORE);
3334 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3337 next[0] = TCP_INPUT_NEXT_DROP;
3338 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3339 if (PREDICT_TRUE (tc0 != 0))
3341 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3342 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3343 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3346 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3353 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3354 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3356 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3357 return frame->n_vectors;
3361 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3362 vlib_frame_t * from_frame)
3364 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3368 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3369 vlib_frame_t * from_frame)
3371 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3375 VLIB_REGISTER_NODE (tcp4_input_node) =
3377 .function = tcp4_input,
3378 .name = "tcp4-input",
3379 /* Takes a vector of packets. */
3380 .vector_size = sizeof (u32),
3381 .n_errors = TCP_N_ERROR,
3382 .error_strings = tcp_error_strings,
3383 .n_next_nodes = TCP_INPUT_N_NEXT,
3386 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3387 foreach_tcp4_input_next
3390 .format_buffer = format_tcp_header,
3391 .format_trace = format_tcp_rx_trace,
3395 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3398 VLIB_REGISTER_NODE (tcp6_input_node) =
3400 .function = tcp6_input,
3401 .name = "tcp6-input",
3402 /* Takes a vector of packets. */
3403 .vector_size = sizeof (u32),
3404 .n_errors = TCP_N_ERROR,
3405 .error_strings = tcp_error_strings,
3406 .n_next_nodes = TCP_INPUT_N_NEXT,
3409 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3410 foreach_tcp6_input_next
3413 .format_buffer = format_tcp_header,
3414 .format_trace = format_tcp_rx_trace,
3418 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3421 tcp_dispatch_table_init (tcp_main_t * tm)
3424 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3425 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3427 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3428 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3431 #define _(t,f,n,e) \
3433 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3434 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3437 /* SYNs for new connections -> tcp-listen. */
3438 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3439 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3440 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3441 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3443 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3444 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3445 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3446 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3448 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3449 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3451 /* SYN-ACK for a SYN */
3452 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3454 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3455 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3456 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3458 /* ACK for for established connection -> tcp-established. */
3459 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3460 /* FIN for for established connection -> tcp-established. */
3461 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3462 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3464 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3465 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3467 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3468 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3470 /* ACK or FIN-ACK to our FIN */
3471 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3472 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3474 /* FIN in reply to our FIN from the other side */
3475 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3476 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3477 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3478 /* FIN confirming that the peer (app) has closed */
3479 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3480 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3481 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3483 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3484 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3486 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3487 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3488 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3490 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3491 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3492 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3494 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3495 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3496 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3497 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3498 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3499 TCP_ERROR_CONNECTION_CLOSED);
3503 static clib_error_t *
3504 tcp_input_init (vlib_main_t * vm)
3506 clib_error_t *error = 0;
3507 tcp_main_t *tm = vnet_get_tcp_main ();
3509 if ((error = vlib_call_init_function (vm, tcp_init)))
3512 /* Initialize dispatch table. */
3513 tcp_dispatch_table_init (tm);
3518 VLIB_INIT_FUNCTION (tcp_input_init);
3521 * fd.io coding-style-patch-verification: ON
3524 * eval: (c-set-style "gnu")