2 * Copyright (c) 2016-2019 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 * @param is_syn set if packet is syn
125 * @return -1 if parsing failed
128 tcp_options_parse (tcp_header_t * th, tcp_options_t * to, u8 is_syn)
131 u8 opt_len, opts_len, kind;
135 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
136 data = (const u8 *) (th + 1);
138 /* Zero out all flags but those set in SYN */
139 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
140 | TCP_OPTS_FLAG_TSTAMP | TCP_OPTION_MSS);
142 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
146 /* Get options length */
147 if (kind == TCP_OPTION_EOL)
149 else if (kind == TCP_OPTION_NOOP)
161 /* weird option length */
162 if (opt_len < 2 || opt_len > opts_len)
172 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
174 to->flags |= TCP_OPTS_FLAG_MSS;
175 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
178 case TCP_OPTION_WINDOW_SCALE:
181 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
183 to->flags |= TCP_OPTS_FLAG_WSCALE;
184 to->wscale = data[2];
185 if (to->wscale > TCP_MAX_WND_SCALE)
186 to->wscale = TCP_MAX_WND_SCALE;
189 case TCP_OPTION_TIMESTAMP:
191 to->flags |= TCP_OPTS_FLAG_TSTAMP;
192 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
193 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
195 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
196 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
199 case TCP_OPTION_SACK_PERMITTED:
202 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
203 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
205 case TCP_OPTION_SACK_BLOCK:
206 /* If SACK permitted was not advertised or a SYN, break */
207 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
210 /* If too short or not correctly formatted, break */
211 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
214 to->flags |= TCP_OPTS_FLAG_SACK;
215 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
216 vec_reset_length (to->sacks);
217 for (j = 0; j < to->n_sack_blocks; j++)
219 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
220 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
221 vec_add1 (to->sacks, b);
225 /* Nothing to see here */
233 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
234 * timestamp to echo and it's less than tsval_recent, drop segment
235 * but still send an ACK in order to retain TCP's mechanism for detecting
236 * and recovering from half-open connections
238 * Or at least that's what the theory says. It seems that this might not work
239 * very well with packet reordering and fast retransmit. XXX
242 tcp_segment_check_paws (tcp_connection_t * tc)
244 return tcp_opts_tstamp (&tc->rcv_opts)
245 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
249 * Update tsval recent
252 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
255 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
256 * of an incoming segment:
257 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
258 * then the TSval from the segment is copied to TS.Recent;
259 * otherwise, the TSval is ignored.
261 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
262 && seq_leq (tc->rcv_las, seq_end))
264 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
265 tc->tsval_recent = tc->rcv_opts.tsval;
266 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
271 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
273 * It first verifies if segment has a wrapped sequence number (PAWS) and then
274 * does the processing associated to the first four steps (ignoring security
275 * and precedence): sequence number, rst bit and syn bit checks.
277 * @return 0 if segments passes validation.
280 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
281 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
283 /* We could get a burst of RSTs interleaved with acks */
284 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
286 tcp_send_reset (tc0);
287 *error0 = TCP_ERROR_CONNECTION_CLOSED;
291 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
293 *error0 = TCP_ERROR_SEGMENT_INVALID;
297 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
299 *error0 = TCP_ERROR_OPTIONS;
303 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
305 *error0 = TCP_ERROR_PAWS;
306 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
307 vnet_buffer (b0)->tcp.seq_end);
309 /* If it just so happens that a segment updates tsval_recent for a
310 * segment over 24 days old, invalidate tsval_recent. */
311 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
312 tcp_time_now_w_thread (tc0->c_thread_index)))
314 tc0->tsval_recent = tc0->rcv_opts.tsval;
315 clib_warning ("paws failed: 24-day old segment");
317 /* Drop after ack if not rst. Resets can fail paws check as per
318 * RFC 7323 sec. 5.2: When an <RST> segment is received, it MUST NOT
319 * be subjected to the PAWS check by verifying an acceptable value in
321 else if (!tcp_rst (th0))
323 tcp_program_ack (wrk, tc0);
324 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 /* SYN/SYN-ACK retransmit */
335 && vnet_buffer (b0)->tcp.seq_number == tc0->rcv_nxt - 1)
337 tcp_options_parse (th0, &tc0->rcv_opts, 1);
338 if (tc0->state == TCP_STATE_SYN_RCVD)
340 tcp_send_synack (tc0);
341 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
342 *error0 = TCP_ERROR_SYNS_RCVD;
346 tcp_program_ack (wrk, tc0);
347 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
348 *error0 = TCP_ERROR_SYN_ACKS_RCVD;
353 *error0 = TCP_ERROR_RCV_WND;
354 /* If our window is 0 and the packet is in sequence, let it pass
355 * through for ack processing. It should be dropped later. */
356 if (!(tc0->rcv_wnd == 0
357 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number))
359 /* If not RST, send dup ack */
362 tcp_program_dupack (wrk, tc0);
363 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
369 /* 2nd: check the RST bit */
370 if (PREDICT_FALSE (tcp_rst (th0)))
372 tcp_connection_reset (tc0);
373 *error0 = TCP_ERROR_RST_RCVD;
377 /* 3rd: check security and precedence (skip) */
379 /* 4th: check the SYN bit (in window) */
380 if (PREDICT_FALSE (tcp_syn (th0)))
382 *error0 = TCP_ERROR_SPURIOUS_SYN;
383 tcp_send_reset (tc0);
387 /* If segment in window, save timestamp */
388 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
389 vnet_buffer (b0)->tcp.seq_end);
397 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
399 /* SND.UNA =< SEG.ACK =< SND.NXT */
400 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
401 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
405 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
407 * Note that although the original article, srtt and rttvar are scaled
408 * to minimize round-off errors, here we don't. Instead, we rely on
409 * better precision time measurements.
411 * TODO support us rtt resolution
414 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
420 err = mrtt - tc->srtt;
422 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
423 * The increase should be bound */
424 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
425 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
426 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
430 /* First measurement. */
432 tc->rttvar = mrtt >> 1;
437 tcp_update_rto (tcp_connection_t * tc)
439 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
440 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
444 * Update RTT estimate and RTO timer
446 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
447 * timing. Middle boxes are known to fiddle with TCP options so we
448 * should give higher priority to ACK timing.
450 * This should be called only if previously sent bytes have been acked.
452 * return 1 if valid rtt 0 otherwise
455 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
459 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
460 * RTT because they're ambiguous. */
461 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
463 if (tcp_in_recovery (tc))
468 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
470 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
471 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
472 mrtt = clib_max ((u32) (sample * THZ), 1);
473 /* Allow measuring of a new RTT */
476 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
477 * snd_una, i.e., the left side of the send window:
478 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
479 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
481 u32 now = tcp_time_now_w_thread (tc->c_thread_index);
482 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
485 /* Ignore dubious measurements */
486 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
489 tcp_estimate_rtt (tc, mrtt);
493 /* If we got here something must've been ACKed so make sure boff is 0,
494 * even if mrtt is not valid since we update the rto lower */
502 tcp_estimate_initial_rtt (tcp_connection_t * tc)
504 u8 thread_index = vlib_num_workers ()? 1 : 0;
509 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
510 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
515 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
516 mrtt = clib_max (mrtt, 1);
517 tc->mrtt_us = (f64) mrtt *TCP_TICK;
520 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
521 tcp_estimate_rtt (tc, mrtt);
526 * Dequeue bytes for connections that have received acks in last burst
529 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
531 u32 thread_index = wrk->vm->thread_index;
532 u32 *pending_deq_acked;
533 tcp_connection_t *tc;
536 if (!vec_len (wrk->pending_deq_acked))
539 pending_deq_acked = wrk->pending_deq_acked;
540 for (i = 0; i < vec_len (pending_deq_acked); i++)
542 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
543 tc->flags &= ~TCP_CONN_DEQ_PENDING;
545 if (PREDICT_FALSE (!tc->burst_acked))
548 /* Dequeue the newly ACKed bytes */
549 stream_session_dequeue_drop (&tc->connection, tc->burst_acked);
551 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
553 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
555 if (seq_leq (tc->psh_seq, tc->snd_una))
556 tc->flags &= ~TCP_CONN_PSH_PENDING;
559 /* If everything has been acked, stop retransmit timer
560 * otherwise update. */
561 tcp_retransmit_timer_update (tc);
563 /* If not congested, update pacer based on our new
565 if (!tcp_in_fastrecovery (tc))
566 tcp_connection_tx_pacer_update (tc);
568 _vec_len (wrk->pending_deq_acked) = 0;
572 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
574 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
576 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
577 tc->flags |= TCP_CONN_DEQ_PENDING;
579 tc->burst_acked += tc->bytes_acked + tc->sack_sb.snd_una_adv;
583 * Check if duplicate ack as per RFC5681 Sec. 2
586 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
589 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
590 && seq_gt (tc->snd_una_max, tc->snd_una)
591 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
592 && (prev_snd_wnd == tc->snd_wnd));
596 * Checks if ack is a congestion control event.
599 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
600 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
602 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
603 * defined to be 'duplicate' */
604 *is_dack = tc->sack_sb.last_sacked_bytes
605 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
607 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
611 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
613 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
614 return hole - sb->holes;
618 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
620 return hole->end - hole->start;
623 sack_scoreboard_hole_t *
624 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
626 if (index != TCP_INVALID_SACK_HOLE_INDEX)
627 return pool_elt_at_index (sb->holes, index);
631 sack_scoreboard_hole_t *
632 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
634 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
635 return pool_elt_at_index (sb->holes, hole->next);
639 sack_scoreboard_hole_t *
640 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
642 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
643 return pool_elt_at_index (sb->holes, hole->prev);
647 sack_scoreboard_hole_t *
648 scoreboard_first_hole (sack_scoreboard_t * sb)
650 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
651 return pool_elt_at_index (sb->holes, sb->head);
655 sack_scoreboard_hole_t *
656 scoreboard_last_hole (sack_scoreboard_t * sb)
658 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
659 return pool_elt_at_index (sb->holes, sb->tail);
664 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
666 sack_scoreboard_hole_t *next, *prev;
668 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
670 next = pool_elt_at_index (sb->holes, hole->next);
671 next->prev = hole->prev;
675 sb->tail = hole->prev;
678 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
680 prev = pool_elt_at_index (sb->holes, hole->prev);
681 prev->next = hole->next;
685 sb->head = hole->next;
688 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
689 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
691 /* Poison the entry */
693 clib_memset (hole, 0xfe, sizeof (*hole));
695 pool_put (sb->holes, hole);
698 static sack_scoreboard_hole_t *
699 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
702 sack_scoreboard_hole_t *hole, *next, *prev;
705 pool_get (sb->holes, hole);
706 clib_memset (hole, 0, sizeof (*hole));
710 hole_index = scoreboard_hole_index (sb, hole);
712 prev = scoreboard_get_hole (sb, prev_index);
715 hole->prev = prev_index;
716 hole->next = prev->next;
718 if ((next = scoreboard_next_hole (sb, hole)))
719 next->prev = hole_index;
721 sb->tail = hole_index;
723 prev->next = hole_index;
727 sb->head = hole_index;
728 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
729 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
736 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
738 sack_scoreboard_hole_t *left, *right;
739 u32 bytes = 0, blks = 0;
742 sb->sacked_bytes = 0;
743 left = scoreboard_last_hole (sb);
747 if (seq_gt (sb->high_sacked, left->end))
749 bytes = sb->high_sacked - left->end;
753 while ((right = left)
754 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
755 && blks < TCP_DUPACK_THRESHOLD
756 /* left not updated if above conditions fail */
757 && (left = scoreboard_prev_hole (sb, right)))
759 bytes += right->start - left->end;
763 /* left is first lost */
768 sb->lost_bytes += scoreboard_hole_bytes (right);
770 left = scoreboard_prev_hole (sb, right);
772 bytes += right->start - left->end;
774 while ((right = left));
777 sb->sacked_bytes = bytes;
781 * Figure out the next hole to retransmit
783 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
785 sack_scoreboard_hole_t *
786 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
787 sack_scoreboard_hole_t * start,
788 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
790 sack_scoreboard_hole_t *hole = 0;
792 hole = start ? start : scoreboard_first_hole (sb);
793 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
794 hole = scoreboard_next_hole (sb, hole);
796 /* Nothing, return */
799 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
803 /* Rule (1): if higher than rxt, less than high_sacked and lost */
804 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
806 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
810 /* Rule (2): available unsent data */
813 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
816 /* Rule (3): if hole not lost */
817 else if (seq_lt (hole->start, sb->high_sacked))
820 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
822 /* Rule (4): if hole beyond high_sacked */
825 ASSERT (seq_geq (hole->start, sb->high_sacked));
828 /* HighRxt MUST NOT be updated */
833 if (hole && seq_lt (sb->high_rxt, hole->start))
834 sb->high_rxt = hole->start;
840 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
842 sack_scoreboard_hole_t *hole;
843 hole = scoreboard_first_hole (sb);
846 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
847 sb->cur_rxt_hole = sb->head;
849 sb->high_rxt = snd_una;
850 sb->rescue_rxt = snd_una - 1;
854 scoreboard_init (sack_scoreboard_t * sb)
856 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
857 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
858 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
862 scoreboard_clear (sack_scoreboard_t * sb)
864 sack_scoreboard_hole_t *hole;
865 while ((hole = scoreboard_first_hole (sb)))
867 scoreboard_remove_hole (sb, hole);
869 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
870 ASSERT (pool_elts (sb->holes) == 0);
871 sb->sacked_bytes = 0;
872 sb->last_sacked_bytes = 0;
873 sb->last_bytes_delivered = 0;
878 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
882 * Test that scoreboard is sane after recovery
884 * Returns 1 if scoreboard is empty or if first hole beyond
888 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
890 sack_scoreboard_hole_t *hole;
891 hole = scoreboard_first_hole (&tc->sack_sb);
892 return (!hole || (seq_geq (hole->start, tc->snd_una)
893 && seq_lt (hole->end, tc->snd_una_max)));
897 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
899 sack_scoreboard_t *sb = &tc->sack_sb;
900 sack_block_t *blk, tmp;
901 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
902 u32 blk_index = 0, old_sacked_bytes, hole_index;
905 sb->last_sacked_bytes = 0;
906 sb->last_bytes_delivered = 0;
909 if (!tcp_opts_sack (&tc->rcv_opts)
910 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
913 old_sacked_bytes = sb->sacked_bytes;
915 /* Remove invalid blocks */
916 blk = tc->rcv_opts.sacks;
917 while (blk < vec_end (tc->rcv_opts.sacks))
919 if (seq_lt (blk->start, blk->end)
920 && seq_gt (blk->start, tc->snd_una)
921 && seq_gt (blk->start, ack)
922 && seq_lt (blk->start, tc->snd_una_max)
923 && seq_leq (blk->end, tc->snd_una_max))
928 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
931 /* Add block for cumulative ack */
932 if (seq_gt (ack, tc->snd_una))
934 tmp.start = tc->snd_una;
936 vec_add1 (tc->rcv_opts.sacks, tmp);
939 if (vec_len (tc->rcv_opts.sacks) == 0)
942 tcp_scoreboard_trace_add (tc, ack);
944 /* Make sure blocks are ordered */
945 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
946 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
947 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
949 tmp = tc->rcv_opts.sacks[i];
950 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
951 tc->rcv_opts.sacks[j] = tmp;
954 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
956 /* If no holes, insert the first that covers all outstanding bytes */
957 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
958 tc->snd_una, tc->snd_una_max);
959 sb->tail = scoreboard_hole_index (sb, last_hole);
960 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
961 sb->high_sacked = tmp.end;
965 /* If we have holes but snd_una_max is beyond the last hole, update
967 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
968 last_hole = scoreboard_last_hole (sb);
969 if (seq_gt (tc->snd_una_max, last_hole->end))
971 if (seq_geq (last_hole->start, sb->high_sacked))
973 last_hole->end = tc->snd_una_max;
975 /* New hole after high sacked block */
976 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
978 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
982 /* Keep track of max byte sacked for when the last hole
984 if (seq_gt (tmp.end, sb->high_sacked))
985 sb->high_sacked = tmp.end;
988 /* Walk the holes with the SACK blocks */
989 hole = pool_elt_at_index (sb->holes, sb->head);
990 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
992 blk = &tc->rcv_opts.sacks[blk_index];
993 if (seq_leq (blk->start, hole->start))
995 /* Block covers hole. Remove hole */
996 if (seq_geq (blk->end, hole->end))
998 next_hole = scoreboard_next_hole (sb, hole);
1000 /* Byte accounting: snd_una needs to be advanced */
1001 if (blk->end == ack)
1005 if (seq_lt (ack, next_hole->start))
1006 sb->snd_una_adv = next_hole->start - ack;
1007 sb->last_bytes_delivered +=
1008 next_hole->start - hole->end;
1012 ASSERT (seq_geq (sb->high_sacked, ack));
1013 sb->snd_una_adv = sb->high_sacked - ack;
1014 sb->last_bytes_delivered += sb->high_sacked - hole->end;
1018 scoreboard_remove_hole (sb, hole);
1021 /* Partial 'head' overlap */
1024 if (seq_gt (blk->end, hole->start))
1026 hole->start = blk->end;
1033 /* Hole must be split */
1034 if (seq_lt (blk->end, hole->end))
1036 hole_index = scoreboard_hole_index (sb, hole);
1037 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1040 /* Pool might've moved */
1041 hole = scoreboard_get_hole (sb, hole_index);
1042 hole->end = blk->start;
1044 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1046 else if (seq_lt (blk->start, hole->end))
1048 hole->end = blk->start;
1050 hole = scoreboard_next_hole (sb, hole);
1054 if (pool_elts (sb->holes) == 1)
1056 hole = scoreboard_first_hole (sb);
1057 if (hole->start == ack + sb->snd_una_adv
1058 && hole->end == tc->snd_una_max)
1059 scoreboard_remove_hole (sb, hole);
1062 scoreboard_update_bytes (tc, sb);
1063 sb->last_sacked_bytes = sb->sacked_bytes
1064 - (old_sacked_bytes - sb->last_bytes_delivered);
1065 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1066 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1067 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
1068 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
1069 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1070 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1071 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1072 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1076 * Try to update snd_wnd based on feedback received from peer.
1078 * If successful, and new window is 'effectively' 0, activate persist
1082 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1084 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1085 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1086 if (seq_lt (tc->snd_wl1, seq)
1087 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1089 tc->snd_wnd = snd_wnd;
1092 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1094 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1096 /* Set persist timer if not set and we just got 0 wnd */
1097 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1098 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1099 tcp_persist_timer_set (tc);
1103 tcp_persist_timer_reset (tc);
1104 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1107 tcp_update_rto (tc);
1114 * Init loss recovery/fast recovery.
1116 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1117 * updated in @ref tcp_cc_handle_event after fast retransmit
1120 tcp_cc_init_congestion (tcp_connection_t * tc)
1122 tcp_fastrecovery_on (tc);
1123 tc->snd_congestion = tc->snd_una_max;
1124 tc->cwnd_acc_bytes = 0;
1125 tc->snd_rxt_bytes = 0;
1126 tc->prev_ssthresh = tc->ssthresh;
1127 tc->prev_cwnd = tc->cwnd;
1128 tc->cc_algo->congestion (tc);
1129 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1133 tcp_cc_recovery_exit (tcp_connection_t * tc)
1136 tcp_update_rto (tc);
1138 tc->snd_nxt = tc->snd_una_max;
1140 tcp_recovery_off (tc);
1141 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1145 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1147 tc->cc_algo->recovered (tc);
1148 tc->snd_rxt_bytes = 0;
1149 tc->rcv_dupacks = 0;
1150 tc->snd_nxt = tc->snd_una_max;
1151 tc->snd_rxt_bytes = 0;
1154 tcp_fastrecovery_off (tc);
1155 tcp_fastrecovery_first_off (tc);
1157 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1161 tcp_cc_congestion_undo (tcp_connection_t * tc)
1163 tc->cwnd = tc->prev_cwnd;
1164 tc->ssthresh = tc->prev_ssthresh;
1165 tc->snd_nxt = tc->snd_una_max;
1166 tc->rcv_dupacks = 0;
1167 if (tcp_in_recovery (tc))
1168 tcp_cc_recovery_exit (tc);
1169 else if (tcp_in_fastrecovery (tc))
1170 tcp_cc_fastrecovery_exit (tc);
1171 ASSERT (tc->rto_boff == 0);
1172 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1176 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1178 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1180 && tcp_opts_tstamp (&tc->rcv_opts)
1181 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1185 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1187 return (tcp_in_fastrecovery (tc)
1188 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1192 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1194 return (tcp_cc_is_spurious_timeout_rxt (tc)
1195 || tcp_cc_is_spurious_fast_rxt (tc));
1199 tcp_cc_recover (tcp_connection_t * tc)
1201 ASSERT (tcp_in_cong_recovery (tc));
1202 if (tcp_cc_is_spurious_retransmit (tc))
1204 tcp_cc_congestion_undo (tc);
1208 if (tcp_in_recovery (tc))
1209 tcp_cc_recovery_exit (tc);
1210 else if (tcp_in_fastrecovery (tc))
1211 tcp_cc_fastrecovery_exit (tc);
1213 ASSERT (tc->rto_boff == 0);
1214 ASSERT (!tcp_in_cong_recovery (tc));
1215 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1220 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1222 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1224 /* Congestion avoidance */
1225 tcp_cc_rcv_ack (tc);
1227 /* If a cumulative ack, make sure dupacks is 0 */
1228 tc->rcv_dupacks = 0;
1230 /* When dupacks hits the threshold we only enter fast retransmit if
1231 * cumulative ack covers more than snd_congestion. Should snd_una
1232 * wrap this test may fail under otherwise valid circumstances.
1233 * Therefore, proactively update snd_congestion when wrap detected. */
1235 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1236 && seq_gt (tc->snd_congestion, tc->snd_una)))
1237 tc->snd_congestion = tc->snd_una - 1;
1241 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1243 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1247 tcp_should_fastrecover (tcp_connection_t * tc)
1249 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1250 || tcp_should_fastrecover_sack (tc));
1254 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1256 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1258 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1259 tc->flags |= TCP_CONN_FRXT_PENDING;
1264 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1266 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1267 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1268 tcp_connection_t *tc;
1272 if (vec_len (wrk->pending_fast_rxt) == 0
1273 && vec_len (wrk->postponed_fast_rxt) == 0)
1276 thread_index = wrk->vm->thread_index;
1277 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1278 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1279 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1280 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1282 _vec_len (wrk->postponed_fast_rxt) = 0;
1283 _vec_len (wrk->pending_fast_rxt) = 0;
1285 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1286 max_burst_size = clib_max (max_burst_size, 1);
1288 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1290 if (n_segs >= VLIB_FRAME_SIZE)
1292 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1296 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1297 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1299 if (!tcp_in_fastrecovery (tc))
1302 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1303 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1305 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1308 tcp_program_fastretransmit (wrk, tc);
1312 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1313 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1314 transport_connection_tx_pacer_update_bytes (&tc->connection,
1316 n_segs += n_segs_now;
1318 _vec_len (ongoing_fast_rxt) = 0;
1319 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1323 * One function to rule them all ... and in the darkness bind them
1326 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1330 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1332 if (tc->bytes_acked)
1334 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1338 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1339 * it account for the bytes that left the network.
1341 else if (is_dack && !tcp_in_recovery (tc))
1343 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1344 ASSERT (tc->snd_una != tc->snd_una_max
1345 || tc->sack_sb.last_sacked_bytes);
1349 /* Pure duplicate ack. If some data got acked, it's handled lower */
1350 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1352 ASSERT (tcp_in_fastrecovery (tc));
1353 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1356 else if (tcp_should_fastrecover (tc))
1360 ASSERT (!tcp_in_fastrecovery (tc));
1362 /* Heuristic to catch potential late dupacks
1363 * after fast retransmit exits */
1364 if (is_dack && tc->snd_una == tc->snd_congestion
1365 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1367 tc->rcv_dupacks = 0;
1371 tcp_cc_init_congestion (tc);
1372 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1374 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1376 tc->cwnd = tc->ssthresh;
1377 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1381 /* Post retransmit update cwnd to ssthresh and account for the
1382 * three segments that have left the network and should've been
1383 * buffered at the receiver XXX */
1384 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1387 /* Constrain rate until we get a partial ack */
1388 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1389 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1390 0 /* start bucket */ );
1391 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1395 else if (!tc->bytes_acked
1396 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1398 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1404 /* Don't allow entry in fast recovery if still in recovery, for now */
1405 else if (0 && is_dack && tcp_in_recovery (tc))
1407 /* If of of the two conditions lower hold, reset dupacks because
1408 * we're probably after timeout (RFC6582 heuristics).
1409 * If Cumulative ack does not cover more than congestion threshold,
1411 * 1) The following doesn't hold: The congestion window is greater
1412 * than SMSS bytes and the difference between highest_ack
1413 * and prev_highest_ack is at most 4*SMSS bytes
1414 * 2) Echoed timestamp in the last non-dup ack does not equal the
1417 if (seq_leq (tc->snd_una, tc->snd_congestion)
1418 && ((!(tc->cwnd > tc->snd_mss
1419 && tc->bytes_acked <= 4 * tc->snd_mss))
1420 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1422 tc->rcv_dupacks = 0;
1427 if (!tc->bytes_acked)
1431 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1434 * Legitimate ACK. 1) See if we can exit recovery
1437 /* Update the pacing rate. For the first partial ack we move from
1438 * the artificially constrained rate to the one after congestion */
1439 tcp_connection_tx_pacer_update (tc);
1441 if (seq_geq (tc->snd_una, tc->snd_congestion))
1443 tcp_retransmit_timer_update (tc);
1445 /* If spurious return, we've already updated everything */
1446 if (tcp_cc_recover (tc))
1448 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1452 tc->snd_nxt = tc->snd_una_max;
1454 /* Treat as congestion avoidance ack */
1455 tcp_cc_rcv_ack (tc);
1460 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1463 /* XXX limit this only to first partial ack? */
1464 tcp_retransmit_timer_update (tc);
1466 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1467 * reset dupacks to 0. Also needed if in congestion recovery */
1468 tc->rcv_dupacks = 0;
1470 /* Post RTO timeout don't try anything fancy */
1471 if (tcp_in_recovery (tc))
1473 tcp_cc_rcv_ack (tc);
1474 transport_add_tx_event (&tc->connection);
1478 /* Remove retransmitted bytes that have been delivered */
1479 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1481 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1482 >= tc->sack_sb.last_bytes_delivered
1483 || (tc->flags & TCP_CONN_FINSNT));
1485 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1486 * remove sacked bytes delivered */
1487 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1489 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1490 - tc->sack_sb.last_bytes_delivered;
1491 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1492 tc->snd_rxt_bytes -= rxt_delivered;
1496 /* Apparently all retransmitted holes have been acked */
1497 tc->snd_rxt_bytes = 0;
1498 tc->sack_sb.high_rxt = tc->snd_una;
1503 tcp_fastrecovery_first_on (tc);
1504 /* Reuse last bytes delivered to track total bytes acked */
1505 tc->sack_sb.last_bytes_delivered += tc->bytes_acked;
1506 if (tc->snd_rxt_bytes > tc->bytes_acked)
1507 tc->snd_rxt_bytes -= tc->bytes_acked;
1509 tc->snd_rxt_bytes = 0;
1512 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1515 * Since this was a partial ack, try to retransmit some more data
1517 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1521 * Process incoming ACK
1524 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1525 tcp_header_t * th, u32 * error)
1527 u32 prev_snd_wnd, prev_snd_una;
1530 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1532 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1533 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1535 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1536 * still has the data so accept the ack */
1537 if (tcp_in_recovery (tc)
1538 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1540 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1541 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1542 tc->snd_una_max = tc->snd_nxt;
1546 /* If we have outstanding data and this is within the window, accept it,
1547 * probably retransmit has timed out. Otherwise ACK segment and then
1549 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1551 tcp_program_ack (wrk, tc);
1552 *error = TCP_ERROR_ACK_FUTURE;
1553 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1554 vnet_buffer (b)->tcp.ack_number);
1558 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1559 vnet_buffer (b)->tcp.ack_number);
1561 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1564 /* If old ACK, probably it's an old dupack */
1565 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1567 *error = TCP_ERROR_ACK_OLD;
1568 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1569 vnet_buffer (b)->tcp.ack_number);
1570 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1571 tcp_cc_handle_event (tc, 1);
1572 /* Don't drop yet */
1577 * Looks okay, process feedback
1580 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1581 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1583 prev_snd_wnd = tc->snd_wnd;
1584 prev_snd_una = tc->snd_una;
1585 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1586 vnet_buffer (b)->tcp.ack_number,
1587 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1588 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1589 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1590 tcp_validate_txf_size (tc, tc->bytes_acked);
1592 if (tc->bytes_acked)
1594 tcp_program_dequeue (wrk, tc);
1595 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1598 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1601 * Check if we have congestion event
1604 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1606 tcp_cc_handle_event (tc, is_dack);
1607 if (!tcp_in_cong_recovery (tc))
1609 *error = TCP_ERROR_ACK_OK;
1612 *error = TCP_ERROR_ACK_DUP;
1613 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1619 * Update congestion control (slow start/congestion avoidance)
1621 tcp_cc_update (tc, b);
1622 *error = TCP_ERROR_ACK_OK;
1627 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1629 if (!tcp_disconnect_pending (tc))
1631 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1632 tcp_disconnect_pending_on (tc);
1637 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1639 u32 thread_index, *pending_disconnects;
1640 tcp_connection_t *tc;
1643 if (!vec_len (wrk->pending_disconnects))
1646 thread_index = wrk->vm->thread_index;
1647 pending_disconnects = wrk->pending_disconnects;
1648 for (i = 0; i < vec_len (pending_disconnects); i++)
1650 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1651 tcp_disconnect_pending_off (tc);
1652 session_transport_closing_notify (&tc->connection);
1654 _vec_len (wrk->pending_disconnects) = 0;
1658 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1661 /* Account for the FIN and send ack */
1663 tcp_program_ack (wrk, tc);
1664 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1665 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1666 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1667 tcp_program_disconnect (wrk, tc);
1668 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1669 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1670 *error = TCP_ERROR_FIN_RCVD;
1674 tcp_sack_vector_is_sane (sack_block_t * sacks)
1677 for (i = 1; i < vec_len (sacks); i++)
1679 if (sacks[i - 1].end == sacks[i].start)
1686 * Build SACK list as per RFC2018.
1688 * Makes sure the first block contains the segment that generated the current
1689 * ACK and the following ones are the ones most recently reported in SACK
1692 * @param tc TCP connection for which the SACK list is updated
1693 * @param start Start sequence number of the newest SACK block
1694 * @param end End sequence of the newest SACK block
1697 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1699 sack_block_t *new_list = 0, *block = 0;
1702 /* If the first segment is ooo add it to the list. Last write might've moved
1703 * rcv_nxt over the first segment. */
1704 if (seq_lt (tc->rcv_nxt, start))
1706 vec_add2 (new_list, block, 1);
1707 block->start = start;
1711 /* Find the blocks still worth keeping. */
1712 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1714 /* Discard if rcv_nxt advanced beyond current block */
1715 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1718 /* Merge or drop if segment overlapped by the new segment */
1719 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1720 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1722 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1723 new_list[0].start = tc->snd_sacks[i].start;
1724 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1725 new_list[0].end = tc->snd_sacks[i].end;
1729 /* Save to new SACK list if we have space. */
1730 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1732 vec_add1 (new_list, tc->snd_sacks[i]);
1736 clib_warning ("sack discarded");
1740 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1742 /* Replace old vector with new one */
1743 vec_free (tc->snd_sacks);
1744 tc->snd_sacks = new_list;
1746 /* Segments should not 'touch' */
1747 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1751 tcp_sack_list_bytes (tcp_connection_t * tc)
1754 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1755 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1759 /** Enqueue data for delivery to application */
1761 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1764 int written, error = TCP_ERROR_ENQUEUED;
1766 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1768 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1769 1 /* queue event */ , 1);
1771 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1773 /* Update rcv_nxt */
1774 if (PREDICT_TRUE (written == data_len))
1776 tc->rcv_nxt += written;
1778 /* If more data written than expected, account for out-of-order bytes. */
1779 else if (written > data_len)
1781 tc->rcv_nxt += written;
1782 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1784 else if (written > 0)
1786 /* We've written something but FIFO is probably full now */
1787 tc->rcv_nxt += written;
1788 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1792 return TCP_ERROR_FIFO_FULL;
1795 /* Update SACK list if need be */
1796 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1798 /* Remove SACK blocks that have been delivered */
1799 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1805 /** Enqueue out-of-order data */
1807 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1813 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1816 /* Enqueue out-of-order data with relative offset */
1817 rv = session_enqueue_stream_connection (&tc->connection, b,
1818 vnet_buffer (b)->tcp.seq_number -
1819 tc->rcv_nxt, 0 /* queue event */ ,
1822 /* Nothing written */
1825 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1826 return TCP_ERROR_FIFO_FULL;
1829 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1831 /* Update SACK list if in use */
1832 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1834 ooo_segment_t *newest;
1837 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1839 /* Get the newest segment from the fifo */
1840 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1843 offset = ooo_segment_offset (s0->rx_fifo, newest);
1844 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1845 start = tc->rcv_nxt + offset;
1846 end = start + ooo_segment_length (s0->rx_fifo, newest);
1847 tcp_update_sack_list (tc, start, end);
1848 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1849 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1853 return TCP_ERROR_ENQUEUED_OOO;
1857 * Check if ACK could be delayed. If ack can be delayed, it should return
1858 * true for a full frame. If we're always acking return 0.
1861 tcp_can_delack (tcp_connection_t * tc)
1863 /* Send ack if ... */
1865 /* just sent a rcv wnd 0 */
1866 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1867 /* constrained to send ack */
1868 || (tc->flags & TCP_CONN_SNDACK) != 0
1869 /* we're almost out of tx wnd */
1870 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1877 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1879 u32 discard, first = b->current_length;
1880 vlib_main_t *vm = vlib_get_main ();
1882 /* Handle multi-buffer segments */
1883 if (n_bytes_to_drop > b->current_length)
1885 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1889 discard = clib_min (n_bytes_to_drop, b->current_length);
1890 vlib_buffer_advance (b, discard);
1891 b = vlib_get_buffer (vm, b->next_buffer);
1892 n_bytes_to_drop -= discard;
1894 while (n_bytes_to_drop);
1895 if (n_bytes_to_drop > first)
1896 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1899 vlib_buffer_advance (b, n_bytes_to_drop);
1900 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1905 * Receive buffer for connection and handle acks
1907 * It handles both in order or out-of-order data.
1910 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1913 u32 error, n_bytes_to_drop, n_data_bytes;
1915 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1916 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1917 ASSERT (n_data_bytes);
1919 /* Handle out-of-order data */
1920 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1922 /* Old sequence numbers allowed through because they overlapped
1924 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1926 /* Completely in the past (possible retransmit). Ack
1927 * retransmissions since we may not have any data to send */
1928 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1930 tcp_program_ack (wrk, tc);
1931 error = TCP_ERROR_SEGMENT_OLD;
1935 /* Chop off the bytes in the past and see if what is left
1936 * can be enqueued in order */
1937 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1938 n_data_bytes -= n_bytes_to_drop;
1939 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1940 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1942 error = TCP_ERROR_SEGMENT_OLD;
1948 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1949 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1950 tcp_program_dupack (wrk, tc);
1951 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1957 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1958 * segments can be enqueued after fifo tail offset changes. */
1959 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1960 if (tcp_can_delack (tc))
1962 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1963 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1967 tcp_program_ack (wrk, tc);
1975 tcp_header_t tcp_header;
1976 tcp_connection_t tcp_connection;
1980 format_tcp_rx_trace (u8 * s, va_list * args)
1982 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1983 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1984 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1985 u32 indent = format_get_indent (s);
1987 s = format (s, "%U\n%U%U",
1988 format_tcp_header, &t->tcp_header, 128,
1989 format_white_space, indent,
1990 format_tcp_connection, &t->tcp_connection, 1);
1996 format_tcp_rx_trace_short (u8 * s, va_list * args)
1998 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1999 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2000 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2002 s = format (s, "%d -> %d (%U)",
2003 clib_net_to_host_u16 (t->tcp_header.dst_port),
2004 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2005 t->tcp_connection.state);
2011 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2012 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2016 clib_memcpy_fast (&t0->tcp_connection, tc0,
2017 sizeof (t0->tcp_connection));
2021 th0 = tcp_buffer_hdr (b0);
2023 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2027 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2028 vlib_frame_t * frame, u8 is_ip4)
2032 n_left = frame->n_vectors;
2033 from = vlib_frame_vector_args (frame);
2037 tcp_connection_t *tc0;
2044 b0 = vlib_get_buffer (vm, bi0);
2046 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2048 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2049 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2051 th0 = tcp_buffer_hdr (b0);
2052 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2061 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2062 u8 is_ip4, u32 evt, u32 val)
2065 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2067 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2070 #define tcp_maybe_inc_counter(node_id, err, count) \
2072 if (next0 != tcp_next_drop (is_ip4)) \
2073 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2074 tcp6_##node_id##_node.index, is_ip4, err, \
2077 #define tcp_inc_counter(node_id, err, count) \
2078 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2079 tcp6_##node_id##_node.index, is_ip4, \
2081 #define tcp_maybe_inc_err_counter(cnts, err) \
2083 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2085 #define tcp_inc_err_counter(cnts, err, val) \
2089 #define tcp_store_err_counters(node_id, cnts) \
2092 for (i = 0; i < TCP_N_ERROR; i++) \
2094 tcp_inc_counter(node_id, i, cnts[i]); \
2099 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2100 vlib_frame_t * frame, int is_ip4)
2102 u32 thread_index = vm->thread_index, errors = 0;
2103 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2104 u32 n_left_from, *from, *first_buffer;
2105 u16 err_counters[TCP_N_ERROR] = { 0 };
2107 if (node->flags & VLIB_NODE_FLAG_TRACE)
2108 tcp_established_trace_frame (vm, node, frame, is_ip4);
2110 first_buffer = from = vlib_frame_vector_args (frame);
2111 n_left_from = frame->n_vectors;
2113 while (n_left_from > 0)
2115 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2118 tcp_connection_t *tc0;
2120 if (n_left_from > 1)
2123 pb = vlib_get_buffer (vm, from[1]);
2124 vlib_prefetch_buffer_header (pb, LOAD);
2125 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2132 b0 = vlib_get_buffer (vm, bi0);
2133 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2136 if (PREDICT_FALSE (tc0 == 0))
2138 error0 = TCP_ERROR_INVALID_CONNECTION;
2142 th0 = tcp_buffer_hdr (b0);
2144 /* TODO header prediction fast path */
2146 /* 1-4: check SEQ, RST, SYN */
2147 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2149 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2153 /* 5: check the ACK field */
2154 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2157 /* 6: check the URG bit TODO */
2159 /* 7: process the segment text */
2160 if (vnet_buffer (b0)->tcp.data_len)
2161 error0 = tcp_segment_rcv (wrk, tc0, b0);
2163 /* 8: check the FIN bit */
2164 if (PREDICT_FALSE (tcp_is_fin (th0)))
2165 tcp_rcv_fin (wrk, tc0, b0, &error0);
2168 tcp_inc_err_counter (err_counters, error0, 1);
2171 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2173 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2174 tcp_store_err_counters (established, err_counters);
2175 tcp_handle_postponed_dequeues (wrk);
2176 tcp_handle_disconnects (wrk);
2177 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2179 return frame->n_vectors;
2183 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2184 vlib_frame_t * from_frame)
2186 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2190 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2191 vlib_frame_t * from_frame)
2193 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2197 VLIB_REGISTER_NODE (tcp4_established_node) =
2199 .function = tcp4_established,
2200 .name = "tcp4-established",
2201 /* Takes a vector of packets. */
2202 .vector_size = sizeof (u32),
2203 .n_errors = TCP_N_ERROR,
2204 .error_strings = tcp_error_strings,
2205 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2208 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2209 foreach_tcp_state_next
2212 .format_trace = format_tcp_rx_trace_short,
2216 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2219 VLIB_REGISTER_NODE (tcp6_established_node) =
2221 .function = tcp6_established,
2222 .name = "tcp6-established",
2223 /* Takes a vector of packets. */
2224 .vector_size = sizeof (u32),
2225 .n_errors = TCP_N_ERROR,
2226 .error_strings = tcp_error_strings,
2227 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2230 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2231 foreach_tcp_state_next
2234 .format_trace = format_tcp_rx_trace_short,
2239 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2241 vlib_node_registration_t tcp4_syn_sent_node;
2242 vlib_node_registration_t tcp6_syn_sent_node;
2245 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2247 transport_connection_t *tmp = 0;
2254 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2257 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2258 && (tc->state == TCP_STATE_LISTEN
2259 || tc->c_rmt_port == hdr->src_port));
2263 handle = session_lookup_half_open_handle (&tc->connection);
2264 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2265 tc->c_proto, tc->c_is_ip4);
2269 if (tmp->lcl_port == hdr->dst_port
2270 && tmp->rmt_port == hdr->src_port)
2272 TCP_DBG ("half-open is valid!");
2280 * Lookup transport connection
2282 static tcp_connection_t *
2283 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2287 transport_connection_t *tconn;
2288 tcp_connection_t *tc;
2293 ip4 = vlib_buffer_get_current (b);
2294 tcp = ip4_next_header (ip4);
2295 tconn = session_lookup_connection_wt4 (fib_index,
2300 TRANSPORT_PROTO_TCP,
2301 thread_index, &is_filtered);
2302 tc = tcp_get_connection_from_transport (tconn);
2303 ASSERT (tcp_lookup_is_valid (tc, tcp));
2308 ip6 = vlib_buffer_get_current (b);
2309 tcp = ip6_next_header (ip6);
2310 tconn = session_lookup_connection_wt6 (fib_index,
2315 TRANSPORT_PROTO_TCP,
2316 thread_index, &is_filtered);
2317 tc = tcp_get_connection_from_transport (tconn);
2318 ASSERT (tcp_lookup_is_valid (tc, tcp));
2324 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2325 vlib_frame_t * from_frame, int is_ip4)
2327 tcp_main_t *tm = vnet_get_tcp_main ();
2328 u32 n_left_from, *from, *first_buffer, errors = 0;
2329 u32 my_thread_index = vm->thread_index;
2330 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2332 from = first_buffer = vlib_frame_vector_args (from_frame);
2333 n_left_from = from_frame->n_vectors;
2335 while (n_left_from > 0)
2337 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2338 tcp_connection_t *tc0, *new_tc0;
2339 tcp_header_t *tcp0 = 0;
2347 b0 = vlib_get_buffer (vm, bi0);
2349 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2350 if (PREDICT_FALSE (tc0 == 0))
2352 error0 = TCP_ERROR_INVALID_CONNECTION;
2356 /* Half-open completed recently but the connection was't removed
2357 * yet by the owning thread */
2358 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2360 /* Make sure the connection actually exists */
2361 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2362 my_thread_index, is_ip4));
2366 ack0 = vnet_buffer (b0)->tcp.ack_number;
2367 seq0 = vnet_buffer (b0)->tcp.seq_number;
2368 tcp0 = tcp_buffer_hdr (b0);
2370 /* Crude check to see if the connection handle does not match
2371 * the packet. Probably connection just switched to established */
2372 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2373 || tcp0->src_port != tc0->c_rmt_port))
2375 error0 = TCP_ERROR_INVALID_CONNECTION;
2379 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2380 && !tcp_syn (tcp0)))
2382 error0 = TCP_ERROR_SEGMENT_INVALID;
2386 /* SYNs consume sequence numbers */
2387 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2390 * 1. check the ACK bit
2394 * If the ACK bit is set
2395 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2396 * the RST bit is set, if so drop the segment and return)
2397 * <SEQ=SEG.ACK><CTL=RST>
2398 * and discard the segment. Return.
2399 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2403 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2405 if (!tcp_rst (tcp0))
2406 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2407 error0 = TCP_ERROR_RCV_WND;
2411 /* Make sure ACK is valid */
2412 if (seq_gt (tc0->snd_una, ack0))
2414 error0 = TCP_ERROR_ACK_INVALID;
2420 * 2. check the RST bit
2425 /* If ACK is acceptable, signal client that peer is not
2426 * willing to accept connection and drop connection*/
2428 tcp_connection_reset (tc0);
2429 error0 = TCP_ERROR_RST_RCVD;
2434 * 3. check the security and precedence (skipped)
2438 * 4. check the SYN bit
2441 /* No SYN flag. Drop. */
2442 if (!tcp_syn (tcp0))
2444 clib_warning ("not synack");
2445 error0 = TCP_ERROR_SEGMENT_INVALID;
2450 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2452 clib_warning ("options parse fail");
2453 error0 = TCP_ERROR_OPTIONS;
2457 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2458 * current thread pool. */
2459 pool_get (tm->connections[my_thread_index], new_tc0);
2460 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2461 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2462 new_tc0->c_thread_index = my_thread_index;
2463 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2464 new_tc0->irs = seq0;
2465 new_tc0->timers[TCP_TIMER_ESTABLISH_AO] = TCP_TIMER_HANDLE_INVALID;
2466 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2467 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2469 /* If this is not the owning thread, wait for syn retransmit to
2470 * expire and cleanup then */
2471 if (tcp_half_open_connection_cleanup (tc0))
2472 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2474 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2476 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2477 new_tc0->tsval_recent_age = tcp_time_now ();
2480 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2481 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2483 new_tc0->rcv_wscale = 0;
2485 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2486 << new_tc0->snd_wscale;
2487 new_tc0->snd_wl1 = seq0;
2488 new_tc0->snd_wl2 = ack0;
2490 tcp_connection_init_vars (new_tc0);
2492 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2493 if (PREDICT_TRUE (tcp_ack (tcp0)))
2495 /* Our SYN is ACKed: we have iss < ack = snd_una */
2497 /* TODO Dequeue acknowledged segments if we support Fast Open */
2498 new_tc0->snd_una = ack0;
2499 new_tc0->state = TCP_STATE_ESTABLISHED;
2501 /* Make sure las is initialized for the wnd computation */
2502 new_tc0->rcv_las = new_tc0->rcv_nxt;
2504 /* Notify app that we have connection. If session layer can't
2505 * allocate session send reset */
2506 if (session_stream_connect_notify (&new_tc0->connection, 0))
2508 clib_warning ("connect notify fail");
2509 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2510 tcp_connection_cleanup (new_tc0);
2514 new_tc0->tx_fifo_size =
2515 transport_tx_fifo_size (&new_tc0->connection);
2516 /* Update rtt with the syn-ack sample */
2517 tcp_estimate_initial_rtt (new_tc0);
2518 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2519 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2521 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2524 new_tc0->state = TCP_STATE_SYN_RCVD;
2526 /* Notify app that we have connection */
2527 if (session_stream_connect_notify (&new_tc0->connection, 0))
2529 tcp_connection_cleanup (new_tc0);
2530 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2531 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2535 new_tc0->tx_fifo_size =
2536 transport_tx_fifo_size (&new_tc0->connection);
2537 new_tc0->rtt_ts = 0;
2538 tcp_init_snd_vars (new_tc0);
2539 tcp_send_synack (new_tc0);
2540 error0 = TCP_ERROR_SYNS_RCVD;
2544 /* Read data, if any */
2545 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2547 clib_warning ("rcvd data in syn-sent");
2548 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2549 if (error0 == TCP_ERROR_ACK_OK)
2550 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2554 tcp_program_ack (wrk, new_tc0);
2559 tcp_inc_counter (syn_sent, error0, 1);
2560 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2562 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2563 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2564 clib_memcpy_fast (&t0->tcp_connection, tc0,
2565 sizeof (t0->tcp_connection));
2569 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2571 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2572 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2574 return from_frame->n_vectors;
2578 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2579 vlib_frame_t * from_frame)
2581 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2585 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2586 vlib_frame_t * from_frame)
2588 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2592 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2594 .function = tcp4_syn_sent,
2595 .name = "tcp4-syn-sent",
2596 /* Takes a vector of packets. */
2597 .vector_size = sizeof (u32),
2598 .n_errors = TCP_N_ERROR,
2599 .error_strings = tcp_error_strings,
2600 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2603 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2604 foreach_tcp_state_next
2607 .format_trace = format_tcp_rx_trace_short,
2611 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2614 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2616 .function = tcp6_syn_sent_rcv,
2617 .name = "tcp6-syn-sent",
2618 /* Takes a vector of packets. */
2619 .vector_size = sizeof (u32),
2620 .n_errors = TCP_N_ERROR,
2621 .error_strings = tcp_error_strings,
2622 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2625 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2626 foreach_tcp_state_next
2629 .format_trace = format_tcp_rx_trace_short,
2633 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2635 vlib_node_registration_t tcp4_rcv_process_node;
2636 vlib_node_registration_t tcp6_rcv_process_node;
2639 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2640 * as per RFC793 p. 64
2643 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2644 vlib_frame_t * from_frame, int is_ip4)
2646 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2647 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2648 u32 n_left_from, *from, max_dequeue;
2650 from = first_buffer = vlib_frame_vector_args (from_frame);
2651 n_left_from = from_frame->n_vectors;
2653 while (n_left_from > 0)
2655 u32 bi0, error0 = TCP_ERROR_NONE;
2656 tcp_header_t *tcp0 = 0;
2657 tcp_connection_t *tc0;
2665 b0 = vlib_get_buffer (vm, bi0);
2666 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2668 if (PREDICT_FALSE (tc0 == 0))
2670 error0 = TCP_ERROR_INVALID_CONNECTION;
2674 tcp0 = tcp_buffer_hdr (b0);
2675 is_fin0 = tcp_is_fin (tcp0);
2679 tcp_connection_t *tmp;
2680 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2682 if (tmp->state != tc0->state)
2684 if (tc0->state != TCP_STATE_CLOSED)
2685 clib_warning ("state changed");
2691 * Special treatment for CLOSED
2693 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2695 error0 = TCP_ERROR_CONNECTION_CLOSED;
2700 * For all other states (except LISTEN)
2703 /* 1-4: check SEQ, RST, SYN */
2704 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2707 /* 5: check the ACK field */
2710 case TCP_STATE_SYN_RCVD:
2712 * If the segment acknowledgment is not acceptable, form a
2714 * <SEQ=SEG.ACK><CTL=RST>
2717 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2719 tcp_connection_reset (tc0);
2720 error0 = TCP_ERROR_ACK_INVALID;
2724 /* Make sure the ack is exactly right */
2725 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2727 tcp_connection_reset (tc0);
2728 error0 = TCP_ERROR_SEGMENT_INVALID;
2732 /* Update rtt and rto */
2733 tcp_estimate_initial_rtt (tc0);
2735 /* Switch state to ESTABLISHED */
2736 tc0->state = TCP_STATE_ESTABLISHED;
2737 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2739 /* Initialize session variables */
2740 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2741 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2742 << tc0->rcv_opts.wscale;
2743 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2744 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2746 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2747 tcp_retransmit_timer_reset (tc0);
2748 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2749 if (stream_session_accept_notify (&tc0->connection))
2751 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2752 tcp_connection_reset (tc0);
2755 error0 = TCP_ERROR_ACK_OK;
2757 case TCP_STATE_ESTABLISHED:
2758 /* We can get packets in established state here because they
2759 * were enqueued before state change */
2760 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2764 case TCP_STATE_FIN_WAIT_1:
2765 /* In addition to the processing for the ESTABLISHED state, if
2766 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2767 * continue processing in that state. */
2768 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2771 /* Still have to send the FIN */
2772 if (tc0->flags & TCP_CONN_FINPNDG)
2774 /* TX fifo finally drained */
2775 max_dequeue = session_tx_fifo_max_dequeue (&tc0->connection);
2776 if (max_dequeue <= tc0->burst_acked)
2779 /* If FIN is ACKed */
2780 else if (tc0->snd_una == tc0->snd_una_max)
2782 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2784 /* Stop all retransmit timers because we have nothing more
2785 * to send. Enable waitclose though because we're willing to
2786 * wait for peer's FIN but not indefinitely. */
2787 tcp_connection_timers_reset (tc0);
2788 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2790 /* Don't try to deq the FIN acked */
2791 if (tc0->burst_acked > 1)
2792 stream_session_dequeue_drop (&tc0->connection,
2793 tc0->burst_acked - 1);
2794 tc0->burst_acked = 0;
2797 case TCP_STATE_FIN_WAIT_2:
2798 /* In addition to the processing for the ESTABLISHED state, if
2799 * the retransmission queue is empty, the user's CLOSE can be
2800 * acknowledged ("ok") but do not delete the TCB. */
2801 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2803 tc0->burst_acked = 0;
2805 case TCP_STATE_CLOSE_WAIT:
2806 /* Do the same processing as for the ESTABLISHED state. */
2807 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2810 if (tc0->flags & TCP_CONN_FINPNDG)
2812 /* TX fifo finally drained */
2813 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2816 tcp_connection_timers_reset (tc0);
2817 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2818 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2822 case TCP_STATE_CLOSING:
2823 /* In addition to the processing for the ESTABLISHED state, if
2824 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2825 * otherwise ignore the segment. */
2826 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2829 tcp_connection_timers_reset (tc0);
2830 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2831 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2835 case TCP_STATE_LAST_ACK:
2836 /* The only thing that [should] arrive in this state is an
2837 * acknowledgment of our FIN. If our FIN is now acknowledged,
2838 * delete the TCB, enter the CLOSED state, and return. */
2840 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2842 error0 = TCP_ERROR_ACK_INVALID;
2845 error0 = TCP_ERROR_ACK_OK;
2846 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2847 /* Apparently our ACK for the peer's FIN was lost */
2848 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2854 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2856 /* Don't free the connection from the data path since
2857 * we can't ensure that we have no packets already enqueued
2858 * to output. Rely instead on the waitclose timer */
2859 tcp_connection_timers_reset (tc0);
2860 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2865 case TCP_STATE_TIME_WAIT:
2866 /* The only thing that can arrive in this state is a
2867 * retransmission of the remote FIN. Acknowledge it, and restart
2868 * the 2 MSL timeout. */
2870 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2873 tcp_program_ack (wrk, tc0);
2874 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2882 /* 6: check the URG bit TODO */
2884 /* 7: process the segment text */
2887 case TCP_STATE_ESTABLISHED:
2888 case TCP_STATE_FIN_WAIT_1:
2889 case TCP_STATE_FIN_WAIT_2:
2890 if (vnet_buffer (b0)->tcp.data_len)
2891 error0 = tcp_segment_rcv (wrk, tc0, b0);
2893 case TCP_STATE_CLOSE_WAIT:
2894 case TCP_STATE_CLOSING:
2895 case TCP_STATE_LAST_ACK:
2896 case TCP_STATE_TIME_WAIT:
2897 /* This should not occur, since a FIN has been received from the
2898 * remote side. Ignore the segment text. */
2902 /* 8: check the FIN bit */
2906 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2910 case TCP_STATE_ESTABLISHED:
2911 /* Account for the FIN and send ack */
2913 tcp_program_ack (wrk, tc0);
2914 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2915 tcp_program_disconnect (wrk, tc0);
2916 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2918 case TCP_STATE_SYN_RCVD:
2919 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2920 * notified yet, set a cleanup timer instead of relying on
2921 * disconnect notify and the implicit close call. */
2922 tcp_connection_timers_reset (tc0);
2925 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2926 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2928 case TCP_STATE_CLOSE_WAIT:
2929 case TCP_STATE_CLOSING:
2930 case TCP_STATE_LAST_ACK:
2933 case TCP_STATE_FIN_WAIT_1:
2935 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
2936 tcp_program_ack (wrk, tc0);
2937 /* Wait for ACK but not forever */
2938 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2940 case TCP_STATE_FIN_WAIT_2:
2941 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2943 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2944 tcp_connection_timers_reset (tc0);
2945 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2946 tcp_program_ack (wrk, tc0);
2948 case TCP_STATE_TIME_WAIT:
2949 /* Remain in the TIME-WAIT state. Restart the time-wait
2952 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2955 error0 = TCP_ERROR_FIN_RCVD;
2959 tcp_inc_counter (rcv_process, error0, 1);
2960 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2962 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2963 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2967 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2969 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
2970 tcp_handle_postponed_dequeues (wrk);
2971 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2973 return from_frame->n_vectors;
2977 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2978 vlib_frame_t * from_frame)
2980 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2984 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2985 vlib_frame_t * from_frame)
2987 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2991 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2993 .function = tcp4_rcv_process,
2994 .name = "tcp4-rcv-process",
2995 /* Takes a vector of packets. */
2996 .vector_size = sizeof (u32),
2997 .n_errors = TCP_N_ERROR,
2998 .error_strings = tcp_error_strings,
2999 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3002 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3003 foreach_tcp_state_next
3006 .format_trace = format_tcp_rx_trace_short,
3010 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
3013 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3015 .function = tcp6_rcv_process,
3016 .name = "tcp6-rcv-process",
3017 /* Takes a vector of packets. */
3018 .vector_size = sizeof (u32),
3019 .n_errors = TCP_N_ERROR,
3020 .error_strings = tcp_error_strings,
3021 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3024 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3025 foreach_tcp_state_next
3028 .format_trace = format_tcp_rx_trace_short,
3032 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
3034 vlib_node_registration_t tcp4_listen_node;
3035 vlib_node_registration_t tcp6_listen_node;
3038 * LISTEN state processing as per RFC 793 p. 65
3041 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3042 vlib_frame_t * from_frame, int is_ip4)
3044 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3045 u32 my_thread_index = vm->thread_index;
3047 from = first_buffer = vlib_frame_vector_args (from_frame);
3048 n_left_from = from_frame->n_vectors;
3050 while (n_left_from > 0)
3055 tcp_header_t *th0 = 0;
3056 tcp_connection_t *lc0;
3059 tcp_connection_t *child0;
3060 u32 error0 = TCP_ERROR_NONE;
3066 b0 = vlib_get_buffer (vm, bi0);
3067 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3071 ip40 = vlib_buffer_get_current (b0);
3072 th0 = ip4_next_header (ip40);
3076 ip60 = vlib_buffer_get_current (b0);
3077 th0 = ip6_next_header (ip60);
3080 /* Create child session. For syn-flood protection use filter */
3082 /* 1. first check for an RST: handled in dispatch */
3083 /* if (tcp_rst (th0))
3087 /* 2. second check for an ACK: handled in dispatch */
3088 /* if (tcp_ack (th0))
3090 tcp_send_reset (b0, is_ip4);
3095 /* 3. check for a SYN (did that already) */
3097 /* Make sure connection wasn't just created */
3098 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3100 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3102 error0 = TCP_ERROR_CREATE_EXISTS;
3106 /* Create child session and send SYN-ACK */
3107 child0 = tcp_connection_alloc (my_thread_index);
3108 child0->c_lcl_port = th0->dst_port;
3109 child0->c_rmt_port = th0->src_port;
3110 child0->c_is_ip4 = is_ip4;
3111 child0->state = TCP_STATE_SYN_RCVD;
3112 child0->c_fib_index = lc0->c_fib_index;
3116 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3117 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3121 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3122 sizeof (ip6_address_t));
3123 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3124 sizeof (ip6_address_t));
3127 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3129 error0 = TCP_ERROR_OPTIONS;
3130 tcp_connection_free (child0);
3134 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3135 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3136 child0->rcv_las = child0->rcv_nxt;
3137 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3139 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3140 * segments are used to initialize PAWS. */
3141 if (tcp_opts_tstamp (&child0->rcv_opts))
3143 child0->tsval_recent = child0->rcv_opts.tsval;
3144 child0->tsval_recent_age = tcp_time_now ();
3147 if (tcp_opts_wscale (&child0->rcv_opts))
3148 child0->snd_wscale = child0->rcv_opts.wscale;
3150 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3151 << child0->snd_wscale;
3152 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3153 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3155 tcp_connection_init_vars (child0);
3156 child0->rto = TCP_RTO_MIN;
3157 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3159 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3162 tcp_connection_cleanup (child0);
3163 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3167 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3168 tcp_send_synack (child0);
3169 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3173 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3175 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3176 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3177 clib_memcpy_fast (&t0->tcp_connection, lc0,
3178 sizeof (t0->tcp_connection));
3181 n_syns += (error0 == TCP_ERROR_NONE);
3184 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3185 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3187 return from_frame->n_vectors;
3191 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3192 vlib_frame_t * from_frame)
3194 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3198 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3199 vlib_frame_t * from_frame)
3201 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3205 VLIB_REGISTER_NODE (tcp4_listen_node) =
3207 .function = tcp4_listen,
3208 .name = "tcp4-listen",
3209 /* Takes a vector of packets. */
3210 .vector_size = sizeof (u32),
3211 .n_errors = TCP_N_ERROR,
3212 .error_strings = tcp_error_strings,
3213 .n_next_nodes = TCP_LISTEN_N_NEXT,
3216 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3217 foreach_tcp_state_next
3220 .format_trace = format_tcp_rx_trace_short,
3224 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3227 VLIB_REGISTER_NODE (tcp6_listen_node) =
3229 .function = tcp6_listen,
3230 .name = "tcp6-listen",
3231 /* Takes a vector of packets. */
3232 .vector_size = sizeof (u32),
3233 .n_errors = TCP_N_ERROR,
3234 .error_strings = tcp_error_strings,
3235 .n_next_nodes = TCP_LISTEN_N_NEXT,
3238 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3239 foreach_tcp_state_next
3242 .format_trace = format_tcp_rx_trace_short,
3246 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3248 vlib_node_registration_t tcp4_input_node;
3249 vlib_node_registration_t tcp6_input_node;
3251 typedef enum _tcp_input_next
3253 TCP_INPUT_NEXT_DROP,
3254 TCP_INPUT_NEXT_LISTEN,
3255 TCP_INPUT_NEXT_RCV_PROCESS,
3256 TCP_INPUT_NEXT_SYN_SENT,
3257 TCP_INPUT_NEXT_ESTABLISHED,
3258 TCP_INPUT_NEXT_RESET,
3259 TCP_INPUT_NEXT_PUNT,
3263 #define foreach_tcp4_input_next \
3264 _ (DROP, "ip4-drop") \
3265 _ (LISTEN, "tcp4-listen") \
3266 _ (RCV_PROCESS, "tcp4-rcv-process") \
3267 _ (SYN_SENT, "tcp4-syn-sent") \
3268 _ (ESTABLISHED, "tcp4-established") \
3269 _ (RESET, "tcp4-reset") \
3270 _ (PUNT, "ip4-punt")
3272 #define foreach_tcp6_input_next \
3273 _ (DROP, "ip6-drop") \
3274 _ (LISTEN, "tcp6-listen") \
3275 _ (RCV_PROCESS, "tcp6-rcv-process") \
3276 _ (SYN_SENT, "tcp6-syn-sent") \
3277 _ (ESTABLISHED, "tcp6-established") \
3278 _ (RESET, "tcp6-reset") \
3279 _ (PUNT, "ip6-punt")
3281 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3284 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3285 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3287 tcp_connection_t *tc;
3292 for (i = 0; i < n_bufs; i++)
3294 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3296 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3297 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3299 tcp = vlib_buffer_get_current (bs[i]);
3300 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3306 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3308 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3310 *next = TCP_INPUT_NEXT_DROP;
3312 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3314 *next = TCP_INPUT_NEXT_PUNT;
3315 *error = TCP_ERROR_PUNT;
3319 *next = TCP_INPUT_NEXT_RESET;
3320 *error = TCP_ERROR_NO_LISTENER;
3324 static inline tcp_connection_t *
3325 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3328 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3329 int n_advance_bytes, n_data_bytes;
3330 transport_connection_t *tc;
3336 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3337 int ip_hdr_bytes = ip4_header_bytes (ip4);
3338 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3340 *error = TCP_ERROR_LENGTH;
3343 tcp = ip4_next_header (ip4);
3344 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3345 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3346 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3348 /* Length check. Checksum computed by ipx_local no need to compute again */
3349 if (PREDICT_FALSE (n_data_bytes < 0))
3351 *error = TCP_ERROR_LENGTH;
3355 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3356 &ip4->src_address, tcp->dst_port,
3357 tcp->src_port, TRANSPORT_PROTO_TCP,
3358 thread_index, &result);
3362 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3363 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3365 *error = TCP_ERROR_LENGTH;
3368 tcp = ip6_next_header (ip6);
3369 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3370 n_advance_bytes = tcp_header_bytes (tcp);
3371 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3373 n_advance_bytes += sizeof (ip6[0]);
3375 if (PREDICT_FALSE (n_data_bytes < 0))
3377 *error = TCP_ERROR_LENGTH;
3381 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3383 ip4_main_t *im = &ip4_main;
3384 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3385 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3388 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3389 &ip6->src_address, tcp->dst_port,
3390 tcp->src_port, TRANSPORT_PROTO_TCP,
3391 thread_index, &result);
3394 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3395 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3396 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3397 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3398 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3400 vnet_buffer (b)->tcp.flags = 0;
3402 *error = result ? TCP_ERROR_NONE + result : *error;
3404 return tcp_get_connection_from_transport (tc);
3408 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3409 vlib_buffer_t * b, u16 * next, u32 * error)
3414 tcp = tcp_buffer_hdr (b);
3415 flags = tcp->flags & filter_flags;
3416 *next = tm->dispatch_table[tc->state][flags].next;
3417 *error = tm->dispatch_table[tc->state][flags].error;
3419 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3420 || *next == TCP_INPUT_NEXT_RESET))
3422 /* Overload tcp flags to store state */
3423 tcp_state_t state = tc->state;
3424 vnet_buffer (b)->tcp.flags = tc->state;
3426 if (*error == TCP_ERROR_DISPATCH)
3427 clib_warning ("tcp conn %u disp error state %U flags %U",
3428 tc->c_c_index, format_tcp_state, state,
3429 format_tcp_flags, (int) flags);
3434 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3435 vlib_frame_t * frame, int is_ip4)
3437 u32 n_left_from, *from, thread_index = vm->thread_index;
3438 tcp_main_t *tm = vnet_get_tcp_main ();
3439 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3440 u16 nexts[VLIB_FRAME_SIZE], *next;
3442 tcp_set_time_now (tcp_get_worker (thread_index));
3444 from = vlib_frame_vector_args (frame);
3445 n_left_from = frame->n_vectors;
3446 vlib_get_buffers (vm, from, bufs, n_left_from);
3451 while (n_left_from >= 4)
3453 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3454 tcp_connection_t *tc0, *tc1;
3457 vlib_prefetch_buffer_header (b[2], STORE);
3458 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3460 vlib_prefetch_buffer_header (b[3], STORE);
3461 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3464 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3466 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3467 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3469 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3471 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3472 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3474 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3475 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3477 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3478 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3482 if (PREDICT_TRUE (tc0 != 0))
3484 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3485 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3486 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3489 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3491 if (PREDICT_TRUE (tc1 != 0))
3493 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3494 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3495 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3498 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3505 while (n_left_from > 0)
3507 tcp_connection_t *tc0;
3508 u32 error0 = TCP_ERROR_NO_LISTENER;
3510 if (n_left_from > 1)
3512 vlib_prefetch_buffer_header (b[1], STORE);
3513 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3516 next[0] = TCP_INPUT_NEXT_DROP;
3517 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3518 if (PREDICT_TRUE (tc0 != 0))
3520 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3521 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3522 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3525 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3532 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3533 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3535 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3536 return frame->n_vectors;
3540 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3541 vlib_frame_t * from_frame)
3543 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3547 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3548 vlib_frame_t * from_frame)
3550 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3554 VLIB_REGISTER_NODE (tcp4_input_node) =
3556 .function = tcp4_input,
3557 .name = "tcp4-input",
3558 /* Takes a vector of packets. */
3559 .vector_size = sizeof (u32),
3560 .n_errors = TCP_N_ERROR,
3561 .error_strings = tcp_error_strings,
3562 .n_next_nodes = TCP_INPUT_N_NEXT,
3565 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3566 foreach_tcp4_input_next
3569 .format_buffer = format_tcp_header,
3570 .format_trace = format_tcp_rx_trace,
3574 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3577 VLIB_REGISTER_NODE (tcp6_input_node) =
3579 .function = tcp6_input,
3580 .name = "tcp6-input",
3581 /* Takes a vector of packets. */
3582 .vector_size = sizeof (u32),
3583 .n_errors = TCP_N_ERROR,
3584 .error_strings = tcp_error_strings,
3585 .n_next_nodes = TCP_INPUT_N_NEXT,
3588 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3589 foreach_tcp6_input_next
3592 .format_buffer = format_tcp_header,
3593 .format_trace = format_tcp_rx_trace,
3597 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3600 tcp_dispatch_table_init (tcp_main_t * tm)
3603 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3604 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3606 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3607 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3610 #define _(t,f,n,e) \
3612 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3613 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3616 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3617 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3618 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3619 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3620 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3621 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3622 TCP_ERROR_ACK_INVALID);
3623 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3624 TCP_ERROR_SEGMENT_INVALID);
3625 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3626 TCP_ERROR_SEGMENT_INVALID);
3627 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3628 TCP_ERROR_INVALID_CONNECTION);
3629 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3630 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3631 TCP_ERROR_SEGMENT_INVALID);
3632 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3633 TCP_ERROR_SEGMENT_INVALID);
3634 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3636 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3637 TCP_ERROR_SEGMENT_INVALID);
3638 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3639 TCP_ERROR_SEGMENT_INVALID);
3640 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3641 TCP_ERROR_SEGMENT_INVALID);
3642 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3643 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3644 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3645 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3646 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3647 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3649 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3650 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3652 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3654 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3655 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3656 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3657 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3659 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3661 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3662 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3663 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3665 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3666 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3667 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3668 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3669 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3670 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3671 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3672 /* SYN-ACK for a SYN */
3673 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3675 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3676 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3677 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3679 /* ACK for for established connection -> tcp-established. */
3680 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3681 /* FIN for for established connection -> tcp-established. */
3682 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3683 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3685 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3687 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3688 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3689 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3691 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3692 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3693 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3694 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3695 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3696 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3697 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3698 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3700 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3701 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3703 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3705 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3706 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3707 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3708 /* ACK or FIN-ACK to our FIN */
3709 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3710 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3712 /* FIN in reply to our FIN from the other side */
3713 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3714 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3715 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3717 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3718 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3719 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3720 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3721 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3722 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3723 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3725 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3726 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3727 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3728 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3730 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3732 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3733 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3734 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3735 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3737 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3738 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3739 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3740 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3742 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3744 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3745 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3746 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3747 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3749 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3750 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3752 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3754 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3755 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3756 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3758 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3759 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3760 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3761 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3762 /* FIN confirming that the peer (app) has closed */
3763 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3764 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3765 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3767 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3768 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3770 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3771 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3773 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3774 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3776 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3777 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3778 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3779 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3781 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3783 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3784 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3785 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3787 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3788 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3789 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3790 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3791 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3792 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3793 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3794 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3796 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3797 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3799 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3801 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3802 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3803 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3804 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3805 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3807 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3808 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3810 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3811 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3812 * incoming segment not containing a RST causes a RST to be sent in
3814 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3815 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3816 TCP_ERROR_CONNECTION_CLOSED);
3817 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3818 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3819 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3824 static clib_error_t *
3825 tcp_input_init (vlib_main_t * vm)
3827 clib_error_t *error = 0;
3828 tcp_main_t *tm = vnet_get_tcp_main ();
3830 if ((error = vlib_call_init_function (vm, tcp_init)))
3833 /* Initialize dispatch table. */
3834 tcp_dispatch_table_init (tm);
3839 VLIB_INIT_FUNCTION (tcp_input_init);
3842 * fd.io coding-style-patch-verification: ON
3845 * eval: (c-set-style "gnu")