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 \
83 * Validate segment sequence number. As per RFC793:
85 * Segment Receive Test
87 * ------- ------- -------------------------------------------
88 * 0 0 SEG.SEQ = RCV.NXT
89 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
91 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
92 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
94 * This ultimately consists in checking if segment falls within the window.
95 * The one important difference compared to RFC793 is that we use rcv_las,
96 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
97 * peer's reference when computing our receive window.
100 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
101 * however, is too strict when we have retransmits. Instead we just check that
102 * the seq is not beyond the right edge and that the end of the segment is not
103 * less than the left edge.
105 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
106 * use rcv_nxt in the right edge window test instead of rcv_las.
110 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
112 return (seq_geq (end_seq, tc->rcv_las)
113 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
117 * Parse TCP header options.
119 * @param th TCP header
120 * @param to TCP options data structure to be populated
121 * @param is_syn set if packet is syn
122 * @return -1 if parsing failed
125 tcp_options_parse (tcp_header_t * th, tcp_options_t * to, u8 is_syn)
128 u8 opt_len, opts_len, kind;
132 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
133 data = (const u8 *) (th + 1);
135 /* Zero out all flags but those set in SYN */
136 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
137 | TCP_OPTS_FLAG_TSTAMP | TCP_OPTION_MSS);
139 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
143 /* Get options length */
144 if (kind == TCP_OPTION_EOL)
146 else if (kind == TCP_OPTION_NOOP)
158 /* weird option length */
159 if (opt_len < 2 || opt_len > opts_len)
169 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
171 to->flags |= TCP_OPTS_FLAG_MSS;
172 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
175 case TCP_OPTION_WINDOW_SCALE:
178 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
180 to->flags |= TCP_OPTS_FLAG_WSCALE;
181 to->wscale = data[2];
182 if (to->wscale > TCP_MAX_WND_SCALE)
183 to->wscale = TCP_MAX_WND_SCALE;
186 case TCP_OPTION_TIMESTAMP:
188 to->flags |= TCP_OPTS_FLAG_TSTAMP;
189 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
190 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
192 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
193 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
196 case TCP_OPTION_SACK_PERMITTED:
199 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
200 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
202 case TCP_OPTION_SACK_BLOCK:
203 /* If SACK permitted was not advertised or a SYN, break */
204 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
207 /* If too short or not correctly formatted, break */
208 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
211 to->flags |= TCP_OPTS_FLAG_SACK;
212 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
213 vec_reset_length (to->sacks);
214 for (j = 0; j < to->n_sack_blocks; j++)
216 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
217 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
218 vec_add1 (to->sacks, b);
222 /* Nothing to see here */
230 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
231 * timestamp to echo and it's less than tsval_recent, drop segment
232 * but still send an ACK in order to retain TCP's mechanism for detecting
233 * and recovering from half-open connections
235 * Or at least that's what the theory says. It seems that this might not work
236 * very well with packet reordering and fast retransmit. XXX
239 tcp_segment_check_paws (tcp_connection_t * tc)
241 return tcp_opts_tstamp (&tc->rcv_opts)
242 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
246 * Update tsval recent
249 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
252 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
253 * of an incoming segment:
254 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
255 * then the TSval from the segment is copied to TS.Recent;
256 * otherwise, the TSval is ignored.
258 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
259 && seq_leq (tc->rcv_las, seq_end))
261 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
262 tc->tsval_recent = tc->rcv_opts.tsval;
263 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
268 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
270 * It first verifies if segment has a wrapped sequence number (PAWS) and then
271 * does the processing associated to the first four steps (ignoring security
272 * and precedence): sequence number, rst bit and syn bit checks.
274 * @return 0 if segments passes validation.
277 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
278 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
280 /* We could get a burst of RSTs interleaved with acks */
281 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
283 tcp_send_reset (tc0);
284 *error0 = TCP_ERROR_CONNECTION_CLOSED;
288 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
290 *error0 = TCP_ERROR_SEGMENT_INVALID;
294 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
296 *error0 = TCP_ERROR_OPTIONS;
300 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
302 *error0 = TCP_ERROR_PAWS;
303 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
304 vnet_buffer (b0)->tcp.seq_end);
306 /* If it just so happens that a segment updates tsval_recent for a
307 * segment over 24 days old, invalidate tsval_recent. */
308 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
309 tcp_time_now_w_thread (tc0->c_thread_index)))
311 tc0->tsval_recent = tc0->rcv_opts.tsval;
312 clib_warning ("paws failed: 24-day old segment");
314 /* Drop after ack if not rst. Resets can fail paws check as per
315 * RFC 7323 sec. 5.2: When an <RST> segment is received, it MUST NOT
316 * be subjected to the PAWS check by verifying an acceptable value in
318 else if (!tcp_rst (th0))
320 tcp_program_ack (tc0);
321 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
326 /* 1st: check sequence number */
327 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
328 vnet_buffer (b0)->tcp.seq_end))
330 /* SYN/SYN-ACK retransmit */
332 && vnet_buffer (b0)->tcp.seq_number == tc0->rcv_nxt - 1)
334 tcp_options_parse (th0, &tc0->rcv_opts, 1);
335 if (tc0->state == TCP_STATE_SYN_RCVD)
337 tcp_send_synack (tc0);
338 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
339 *error0 = TCP_ERROR_SYNS_RCVD;
343 tcp_program_ack (tc0);
344 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
345 *error0 = TCP_ERROR_SYN_ACKS_RCVD;
350 /* If our window is 0 and the packet is in sequence, let it pass
351 * through for ack processing. It should be dropped later. */
352 if (tc0->rcv_wnd < tc0->snd_mss
353 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
356 /* If we entered recovery and peer did so as well, there's a chance that
357 * dup acks won't be acceptable on either end because seq_end may be less
358 * than rcv_las. This can happen if acks are lost in both directions. */
359 if (tcp_in_recovery (tc0)
360 && seq_geq (vnet_buffer (b0)->tcp.seq_number,
361 tc0->rcv_las - tc0->rcv_wnd)
362 && seq_leq (vnet_buffer (b0)->tcp.seq_end,
363 tc0->rcv_nxt + tc0->rcv_wnd))
366 *error0 = TCP_ERROR_RCV_WND;
368 /* If not RST, send dup ack */
371 tcp_program_dupack (tc0);
372 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
380 /* 2nd: check the RST bit */
381 if (PREDICT_FALSE (tcp_rst (th0)))
383 tcp_connection_reset (tc0);
384 *error0 = TCP_ERROR_RST_RCVD;
388 /* 3rd: check security and precedence (skip) */
390 /* 4th: check the SYN bit (in window) */
391 if (PREDICT_FALSE (tcp_syn (th0)))
393 /* As per RFC5961 send challenge ack instead of reset */
394 tcp_program_ack (tc0);
395 *error0 = TCP_ERROR_SPURIOUS_SYN;
399 /* If segment in window, save timestamp */
400 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
401 vnet_buffer (b0)->tcp.seq_end);
409 tcp_rcv_ack_no_cc (tcp_connection_t * tc, vlib_buffer_t * b, u32 * error)
411 /* SND.UNA =< SEG.ACK =< SND.NXT */
412 if (!(seq_leq (tc->snd_una, vnet_buffer (b)->tcp.ack_number)
413 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
415 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
416 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
418 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
421 *error = TCP_ERROR_ACK_INVALID;
426 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
427 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
428 *error = TCP_ERROR_ACK_OK;
433 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
435 * Note that although the original article, srtt and rttvar are scaled
436 * to minimize round-off errors, here we don't. Instead, we rely on
437 * better precision time measurements.
439 * TODO support us rtt resolution
442 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
448 err = mrtt - tc->srtt;
450 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
451 * The increase should be bound */
452 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
453 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
454 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
458 /* First measurement. */
460 tc->rttvar = mrtt >> 1;
464 #ifndef CLIB_MARCH_VARIANT
466 tcp_update_rto (tcp_connection_t * tc)
468 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
469 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
471 #endif /* CLIB_MARCH_VARIANT */
474 * Update RTT estimate and RTO timer
476 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
477 * timing. Middle boxes are known to fiddle with TCP options so we
478 * should give higher priority to ACK timing.
480 * This should be called only if previously sent bytes have been acked.
482 * return 1 if valid rtt 0 otherwise
485 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
489 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
490 * RTT because they're ambiguous. */
491 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
493 if (tcp_in_recovery (tc))
498 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
500 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
501 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
502 mrtt = clib_max ((u32) (sample * THZ), 1);
503 /* Allow measuring of a new RTT */
506 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
507 * snd_una, i.e., the left side of the send window:
508 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
509 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
511 u32 now = tcp_tstamp (tc);
512 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
515 /* Ignore dubious measurements */
516 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
519 tcp_estimate_rtt (tc, mrtt);
523 /* If we got here something must've been ACKed so make sure boff is 0,
524 * even if mrtt is not valid since we update the rto lower */
532 tcp_estimate_initial_rtt (tcp_connection_t * tc)
534 u8 thread_index = vlib_num_workers ()? 1 : 0;
539 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
540 tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001);
541 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
546 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
547 mrtt = clib_max (mrtt, 1);
548 /* Due to retransmits we don't know the initial mrtt */
549 if (tc->rto_boff && mrtt > 1 * THZ)
551 tc->mrtt_us = (f64) mrtt *TCP_TICK;
554 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
555 tcp_estimate_rtt (tc, mrtt);
560 * Dequeue bytes for connections that have received acks in last burst
563 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
565 u32 thread_index = wrk->vm->thread_index;
566 u32 *pending_deq_acked;
567 tcp_connection_t *tc;
570 if (!vec_len (wrk->pending_deq_acked))
573 pending_deq_acked = wrk->pending_deq_acked;
574 for (i = 0; i < vec_len (pending_deq_acked); i++)
576 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
577 tc->flags &= ~TCP_CONN_DEQ_PENDING;
579 if (PREDICT_FALSE (!tc->burst_acked))
582 /* Dequeue the newly ACKed bytes */
583 session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
585 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
587 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
589 if (seq_leq (tc->psh_seq, tc->snd_una))
590 tc->flags &= ~TCP_CONN_PSH_PENDING;
593 /* If everything has been acked, stop retransmit timer
594 * otherwise update. */
595 tcp_retransmit_timer_update (tc);
597 /* If not congested, update pacer based on our new
599 if (!tcp_in_fastrecovery (tc))
600 tcp_connection_tx_pacer_update (tc);
602 _vec_len (wrk->pending_deq_acked) = 0;
606 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
608 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
610 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
611 tc->flags |= TCP_CONN_DEQ_PENDING;
613 tc->burst_acked += tc->bytes_acked + tc->sack_sb.snd_una_adv;
617 * Check if duplicate ack as per RFC5681 Sec. 2
620 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
623 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
624 && seq_gt (tc->snd_nxt, tc->snd_una)
625 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
626 && (prev_snd_wnd == tc->snd_wnd));
630 * Checks if ack is a congestion control event.
633 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
634 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
636 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
637 * defined to be 'duplicate' */
638 *is_dack = tc->sack_sb.last_sacked_bytes
639 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
641 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
644 #ifndef CLIB_MARCH_VARIANT
646 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
648 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
649 return hole - sb->holes;
653 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
655 return hole->end - hole->start;
658 sack_scoreboard_hole_t *
659 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
661 if (index != TCP_INVALID_SACK_HOLE_INDEX)
662 return pool_elt_at_index (sb->holes, index);
666 sack_scoreboard_hole_t *
667 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
669 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
670 return pool_elt_at_index (sb->holes, hole->next);
674 sack_scoreboard_hole_t *
675 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
677 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
678 return pool_elt_at_index (sb->holes, hole->prev);
682 sack_scoreboard_hole_t *
683 scoreboard_first_hole (sack_scoreboard_t * sb)
685 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
686 return pool_elt_at_index (sb->holes, sb->head);
690 sack_scoreboard_hole_t *
691 scoreboard_last_hole (sack_scoreboard_t * sb)
693 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
694 return pool_elt_at_index (sb->holes, sb->tail);
699 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
701 sack_scoreboard_hole_t *next, *prev;
703 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
705 next = pool_elt_at_index (sb->holes, hole->next);
706 next->prev = hole->prev;
710 sb->tail = hole->prev;
713 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
715 prev = pool_elt_at_index (sb->holes, hole->prev);
716 prev->next = hole->next;
720 sb->head = hole->next;
723 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
724 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
726 /* Poison the entry */
728 clib_memset (hole, 0xfe, sizeof (*hole));
730 pool_put (sb->holes, hole);
733 static sack_scoreboard_hole_t *
734 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
737 sack_scoreboard_hole_t *hole, *next, *prev;
740 pool_get (sb->holes, hole);
741 clib_memset (hole, 0, sizeof (*hole));
745 hole_index = scoreboard_hole_index (sb, hole);
747 prev = scoreboard_get_hole (sb, prev_index);
750 hole->prev = prev_index;
751 hole->next = prev->next;
753 if ((next = scoreboard_next_hole (sb, hole)))
754 next->prev = hole_index;
756 sb->tail = hole_index;
758 prev->next = hole_index;
762 sb->head = hole_index;
763 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
764 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
769 #endif /* CLIB_MARCH_VARIANT */
771 #ifndef CLIB_MARCH_VARIANT
773 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
775 sack_scoreboard_hole_t *left, *right;
776 u32 bytes = 0, blks = 0;
778 sb->last_lost_bytes = 0;
780 sb->sacked_bytes = 0;
781 left = scoreboard_last_hole (sb);
785 if (seq_gt (sb->high_sacked, left->end))
787 bytes = sb->high_sacked - left->end;
791 while ((right = left)
792 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
793 && blks < TCP_DUPACK_THRESHOLD
794 /* left not updated if above conditions fail */
795 && (left = scoreboard_prev_hole (sb, right)))
797 bytes += right->start - left->end;
801 /* left is first lost */
806 sb->lost_bytes += scoreboard_hole_bytes (right);
807 sb->last_lost_bytes += left->is_lost ? 0 : left->end - left->start;
809 left = scoreboard_prev_hole (sb, right);
811 bytes += right->start - left->end;
813 while ((right = left));
816 sb->sacked_bytes = bytes;
820 * Figure out the next hole to retransmit
822 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
824 sack_scoreboard_hole_t *
825 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
826 sack_scoreboard_hole_t * start,
827 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
829 sack_scoreboard_hole_t *hole = 0;
831 hole = start ? start : scoreboard_first_hole (sb);
832 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
833 hole = scoreboard_next_hole (sb, hole);
835 /* Nothing, return */
838 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
842 /* Rule (1): if higher than rxt, less than high_sacked and lost */
843 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
845 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
849 /* Rule (2): available unsent data */
852 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
855 /* Rule (3): if hole not lost */
856 else if (seq_lt (hole->start, sb->high_sacked))
859 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
861 /* Rule (4): if hole beyond high_sacked */
864 ASSERT (seq_geq (hole->start, sb->high_sacked));
867 /* HighRxt MUST NOT be updated */
872 if (hole && seq_lt (sb->high_rxt, hole->start))
873 sb->high_rxt = hole->start;
877 #endif /* CLIB_MARCH_VARIANT */
880 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
882 sack_scoreboard_hole_t *hole;
883 hole = scoreboard_first_hole (sb);
886 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
887 sb->cur_rxt_hole = sb->head;
889 sb->high_rxt = snd_una;
890 sb->rescue_rxt = snd_una - 1;
893 #ifndef CLIB_MARCH_VARIANT
895 scoreboard_init (sack_scoreboard_t * sb)
897 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
898 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
899 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
903 scoreboard_clear (sack_scoreboard_t * sb)
905 sack_scoreboard_hole_t *hole;
906 while ((hole = scoreboard_first_hole (sb)))
908 scoreboard_remove_hole (sb, hole);
910 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
911 ASSERT (pool_elts (sb->holes) == 0);
912 sb->sacked_bytes = 0;
913 sb->last_sacked_bytes = 0;
914 sb->last_bytes_delivered = 0;
919 sb->last_lost_bytes = 0;
920 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
922 #endif /* CLIB_MARCH_VARIANT */
925 * Test that scoreboard is sane after recovery
927 * Returns 1 if scoreboard is empty or if first hole beyond
931 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
933 sack_scoreboard_hole_t *hole;
934 hole = scoreboard_first_hole (&tc->sack_sb);
935 return (!hole || (seq_geq (hole->start, tc->snd_una)
936 && seq_lt (hole->end, tc->snd_nxt)));
939 #ifndef CLIB_MARCH_VARIANT
942 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
944 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
945 u32 blk_index = 0, old_sacked_bytes, hole_index;
946 sack_scoreboard_t *sb = &tc->sack_sb;
947 sack_block_t *blk, tmp;
950 sb->last_sacked_bytes = 0;
951 sb->last_bytes_delivered = 0;
954 if (!tcp_opts_sack (&tc->rcv_opts)
955 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
958 old_sacked_bytes = sb->sacked_bytes;
960 /* Remove invalid blocks */
961 blk = tc->rcv_opts.sacks;
962 while (blk < vec_end (tc->rcv_opts.sacks))
964 if (seq_lt (blk->start, blk->end)
965 && seq_gt (blk->start, tc->snd_una)
966 && seq_gt (blk->start, ack)
967 && seq_lt (blk->start, tc->snd_nxt)
968 && seq_leq (blk->end, tc->snd_nxt))
973 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
976 /* Add block for cumulative ack */
977 if (seq_gt (ack, tc->snd_una))
979 tmp.start = tc->snd_una;
981 vec_add1 (tc->rcv_opts.sacks, tmp);
984 if (vec_len (tc->rcv_opts.sacks) == 0)
987 tcp_scoreboard_trace_add (tc, ack);
989 /* Make sure blocks are ordered */
990 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
991 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
992 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
994 tmp = tc->rcv_opts.sacks[i];
995 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
996 tc->rcv_opts.sacks[j] = tmp;
999 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1001 /* If no holes, insert the first that covers all outstanding bytes */
1002 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1003 tc->snd_una, tc->snd_nxt);
1004 sb->tail = scoreboard_hole_index (sb, last_hole);
1005 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
1006 sb->high_sacked = tmp.end;
1010 /* If we have holes but snd_una_max is beyond the last hole, update
1012 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
1013 last_hole = scoreboard_last_hole (sb);
1014 if (seq_gt (tc->snd_nxt, last_hole->end))
1016 if (seq_geq (last_hole->start, sb->high_sacked))
1018 last_hole->end = tc->snd_nxt;
1020 /* New hole after high sacked block */
1021 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1023 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1027 /* Keep track of max byte sacked for when the last hole
1029 if (seq_gt (tmp.end, sb->high_sacked))
1030 sb->high_sacked = tmp.end;
1033 /* Walk the holes with the SACK blocks */
1034 hole = pool_elt_at_index (sb->holes, sb->head);
1035 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
1037 blk = &tc->rcv_opts.sacks[blk_index];
1038 if (seq_leq (blk->start, hole->start))
1040 /* Block covers hole. Remove hole */
1041 if (seq_geq (blk->end, hole->end))
1043 next_hole = scoreboard_next_hole (sb, hole);
1045 /* Byte accounting: snd_una needs to be advanced */
1046 if (blk->end == ack)
1050 if (seq_lt (ack, next_hole->start))
1051 sb->snd_una_adv = next_hole->start - ack;
1052 sb->last_bytes_delivered +=
1053 next_hole->start - hole->end;
1057 ASSERT (seq_geq (sb->high_sacked, ack));
1058 sb->snd_una_adv = sb->high_sacked - ack;
1059 sb->last_bytes_delivered += sb->high_sacked - hole->end;
1062 scoreboard_remove_hole (sb, hole);
1065 /* Partial 'head' overlap */
1068 if (seq_gt (blk->end, hole->start))
1070 hole->start = blk->end;
1077 /* Hole must be split */
1078 if (seq_lt (blk->end, hole->end))
1080 hole_index = scoreboard_hole_index (sb, hole);
1081 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1084 /* Pool might've moved */
1085 hole = scoreboard_get_hole (sb, hole_index);
1086 hole->end = blk->start;
1088 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1090 else if (seq_lt (blk->start, hole->end))
1092 hole->end = blk->start;
1094 hole = scoreboard_next_hole (sb, hole);
1098 if (pool_elts (sb->holes) == 1)
1100 hole = scoreboard_first_hole (sb);
1101 if (hole->start == ack + sb->snd_una_adv && hole->end == tc->snd_nxt)
1102 scoreboard_remove_hole (sb, hole);
1105 scoreboard_update_bytes (tc, sb);
1106 sb->last_sacked_bytes = sb->sacked_bytes
1107 - (old_sacked_bytes - sb->last_bytes_delivered);
1109 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1110 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1111 || sb->sacked_bytes < tc->snd_nxt - seq_max (tc->snd_una, ack));
1112 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1113 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1114 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1115 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1116 ASSERT (sb->last_lost_bytes <= sb->lost_bytes);
1118 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1120 #endif /* CLIB_MARCH_VARIANT */
1123 * Try to update snd_wnd based on feedback received from peer.
1125 * If successful, and new window is 'effectively' 0, activate persist
1129 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1131 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1132 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1133 if (seq_lt (tc->snd_wl1, seq)
1134 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1136 tc->snd_wnd = snd_wnd;
1139 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1141 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1143 /* Set persist timer if not set and we just got 0 wnd */
1144 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1145 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1146 tcp_persist_timer_set (tc);
1150 tcp_persist_timer_reset (tc);
1151 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1154 tcp_update_rto (tc);
1160 #ifndef CLIB_MARCH_VARIANT
1162 * Init loss recovery/fast recovery.
1164 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1165 * updated in @ref tcp_cc_handle_event after fast retransmit
1168 tcp_cc_init_congestion (tcp_connection_t * tc)
1170 tcp_fastrecovery_on (tc);
1171 tc->snd_congestion = tc->snd_nxt;
1172 tc->cwnd_acc_bytes = 0;
1173 tc->snd_rxt_bytes = 0;
1174 tc->prev_ssthresh = tc->ssthresh;
1175 tc->prev_cwnd = tc->cwnd;
1176 tc->cc_algo->congestion (tc);
1177 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1179 #endif /* CLIB_MARCH_VARIANT */
1182 tcp_cc_recovery_exit (tcp_connection_t * tc)
1185 tcp_update_rto (tc);
1188 tcp_recovery_off (tc);
1189 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1192 #ifndef CLIB_MARCH_VARIANT
1194 tcp_cc_fastrecovery_clear (tcp_connection_t * tc)
1196 tc->snd_rxt_bytes = 0;
1197 tc->rcv_dupacks = 0;
1200 tcp_fastrecovery_off (tc);
1201 tcp_fastrecovery_first_off (tc);
1202 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1204 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1206 #endif /* CLIB_MARCH_VARIANT */
1209 tcp_cc_congestion_undo (tcp_connection_t * tc)
1211 tc->cwnd = tc->prev_cwnd;
1212 tc->ssthresh = tc->prev_ssthresh;
1213 tc->rcv_dupacks = 0;
1214 if (tcp_in_recovery (tc))
1216 tcp_cc_recovery_exit (tc);
1217 tc->snd_nxt = seq_max (tc->snd_nxt, tc->snd_congestion);
1219 else if (tcp_in_fastrecovery (tc))
1221 tcp_cc_fastrecovery_clear (tc);
1223 tcp_cc_undo_recovery (tc);
1224 ASSERT (tc->rto_boff == 0);
1225 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1229 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1231 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1233 && tcp_opts_tstamp (&tc->rcv_opts)
1234 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1238 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1240 return (tcp_in_fastrecovery (tc)
1241 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1245 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1247 return (tcp_cc_is_spurious_timeout_rxt (tc)
1248 || tcp_cc_is_spurious_fast_rxt (tc));
1252 tcp_cc_recover (tcp_connection_t * tc)
1254 ASSERT (tcp_in_cong_recovery (tc));
1255 if (tcp_cc_is_spurious_retransmit (tc))
1257 tcp_cc_congestion_undo (tc);
1261 if (tcp_in_recovery (tc))
1262 tcp_cc_recovery_exit (tc);
1263 else if (tcp_in_fastrecovery (tc))
1265 tcp_cc_recovered (tc);
1266 tcp_cc_fastrecovery_clear (tc);
1269 ASSERT (tc->rto_boff == 0);
1270 ASSERT (!tcp_in_cong_recovery (tc));
1271 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1276 tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1278 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1280 /* Congestion avoidance */
1281 tcp_cc_rcv_ack (tc, rs);
1283 /* If a cumulative ack, make sure dupacks is 0 */
1284 tc->rcv_dupacks = 0;
1286 /* When dupacks hits the threshold we only enter fast retransmit if
1287 * cumulative ack covers more than snd_congestion. Should snd_una
1288 * wrap this test may fail under otherwise valid circumstances.
1289 * Therefore, proactively update snd_congestion when wrap detected. */
1291 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1292 && seq_gt (tc->snd_congestion, tc->snd_una)))
1293 tc->snd_congestion = tc->snd_una - 1;
1297 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1299 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1303 tcp_should_fastrecover (tcp_connection_t * tc)
1305 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1306 || tcp_should_fastrecover_sack (tc));
1310 * One function to rule them all ... and in the darkness bind them
1313 tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs,
1318 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1320 if (tc->bytes_acked)
1322 tcp_program_fastretransmit (tc);
1326 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1327 * it account for the bytes that left the network.
1329 else if (is_dack && !tcp_in_recovery (tc))
1331 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1332 ASSERT (tc->snd_una != tc->snd_nxt || tc->sack_sb.last_sacked_bytes);
1336 /* Pure duplicate ack. If some data got acked, it's handled lower */
1337 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1339 ASSERT (tcp_in_fastrecovery (tc));
1340 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1343 else if (tcp_should_fastrecover (tc))
1347 ASSERT (!tcp_in_fastrecovery (tc));
1349 /* Heuristic to catch potential late dupacks
1350 * after fast retransmit exits */
1351 if (is_dack && tc->snd_una == tc->snd_congestion
1352 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1354 tc->rcv_dupacks = 0;
1358 tcp_cc_init_congestion (tc);
1359 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1361 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1363 tc->cwnd = tc->ssthresh;
1364 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1368 /* Post retransmit update cwnd to ssthresh and account for the
1369 * three segments that have left the network and should've been
1370 * buffered at the receiver XXX */
1371 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1374 /* Constrain rate until we get a partial ack */
1375 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1376 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1377 0 /* start bucket */ );
1378 tcp_program_fastretransmit (tc);
1381 else if (!tc->bytes_acked
1382 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1384 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1390 /* Don't allow entry in fast recovery if still in recovery, for now */
1391 else if (0 && is_dack && tcp_in_recovery (tc))
1393 /* If of of the two conditions lower hold, reset dupacks because
1394 * we're probably after timeout (RFC6582 heuristics).
1395 * If Cumulative ack does not cover more than congestion threshold,
1397 * 1) The following doesn't hold: The congestion window is greater
1398 * than SMSS bytes and the difference between highest_ack
1399 * and prev_highest_ack is at most 4*SMSS bytes
1400 * 2) Echoed timestamp in the last non-dup ack does not equal the
1403 if (seq_leq (tc->snd_una, tc->snd_congestion)
1404 && ((!(tc->cwnd > tc->snd_mss
1405 && tc->bytes_acked <= 4 * tc->snd_mss))
1406 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1408 tc->rcv_dupacks = 0;
1413 if (!tc->bytes_acked)
1417 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1420 * Legitimate ACK. 1) See if we can exit recovery
1423 /* Update the pacing rate. For the first partial ack we move from
1424 * the artificially constrained rate to the one after congestion */
1425 tcp_connection_tx_pacer_update (tc);
1427 if (seq_geq (tc->snd_una, tc->snd_congestion))
1429 tcp_retransmit_timer_update (tc);
1431 /* If spurious return, we've already updated everything */
1432 if (tcp_cc_recover (tc))
1434 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1438 /* Treat as congestion avoidance ack */
1439 tcp_cc_rcv_ack (tc, rs);
1444 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1447 /* XXX limit this only to first partial ack? */
1448 tcp_retransmit_timer_update (tc);
1450 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1451 * reset dupacks to 0. Also needed if in congestion recovery */
1452 tc->rcv_dupacks = 0;
1454 /* Post RTO timeout don't try anything fancy */
1455 if (tcp_in_recovery (tc))
1457 tcp_cc_rcv_ack (tc, rs);
1458 transport_add_tx_event (&tc->connection);
1462 /* Remove retransmitted bytes that have been delivered */
1463 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1465 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1466 >= tc->sack_sb.last_bytes_delivered
1467 || (tc->flags & TCP_CONN_FINSNT));
1469 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1470 * remove sacked bytes delivered */
1471 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1473 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1474 - tc->sack_sb.last_bytes_delivered;
1475 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1476 tc->snd_rxt_bytes -= rxt_delivered;
1480 /* Apparently all retransmitted holes have been acked */
1481 tc->snd_rxt_bytes = 0;
1482 tc->sack_sb.high_rxt = tc->snd_una;
1487 tcp_fastrecovery_first_on (tc);
1488 if (tc->snd_rxt_bytes > tc->bytes_acked)
1489 tc->snd_rxt_bytes -= tc->bytes_acked;
1491 tc->snd_rxt_bytes = 0;
1494 tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs);
1497 * Since this was a partial ack, try to retransmit some more data
1499 tcp_program_fastretransmit (tc);
1503 * Process incoming ACK
1506 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1507 tcp_header_t * th, u32 * error)
1509 u32 prev_snd_wnd, prev_snd_una;
1510 tcp_rate_sample_t rs = { 0 };
1513 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1515 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1516 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1518 /* We've probably entered recovery and the peer still has some
1519 * of the data we've sent. Update snd_nxt and accept the ack */
1520 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1521 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1523 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1527 *error = TCP_ERROR_ACK_FUTURE;
1528 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1529 vnet_buffer (b)->tcp.ack_number);
1533 /* If old ACK, probably it's an old dupack */
1534 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1536 *error = TCP_ERROR_ACK_OLD;
1537 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1538 vnet_buffer (b)->tcp.ack_number);
1539 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1540 tcp_cc_handle_event (tc, 0, 1);
1541 /* Don't drop yet */
1548 * Looks okay, process feedback
1550 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1551 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1553 prev_snd_wnd = tc->snd_wnd;
1554 prev_snd_una = tc->snd_una;
1555 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1556 vnet_buffer (b)->tcp.ack_number,
1557 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1558 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1559 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1560 tcp_validate_txf_size (tc, tc->bytes_acked);
1562 if (tc->bytes_acked)
1564 tcp_program_dequeue (wrk, tc);
1565 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1568 if (tc->flags & TCP_CONN_RATE_SAMPLE)
1569 tcp_bt_sample_delivery_rate (tc, &rs);
1571 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1574 * Check if we have congestion event
1577 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1579 tcp_cc_handle_event (tc, &rs, is_dack);
1580 if (!tcp_in_cong_recovery (tc))
1582 *error = TCP_ERROR_ACK_OK;
1585 *error = TCP_ERROR_ACK_DUP;
1586 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1592 * Update congestion control (slow start/congestion avoidance)
1594 tcp_cc_update (tc, &rs);
1595 *error = TCP_ERROR_ACK_OK;
1600 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1602 if (!tcp_disconnect_pending (tc))
1604 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1605 tcp_disconnect_pending_on (tc);
1610 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1612 u32 thread_index, *pending_disconnects;
1613 tcp_connection_t *tc;
1616 if (!vec_len (wrk->pending_disconnects))
1619 thread_index = wrk->vm->thread_index;
1620 pending_disconnects = wrk->pending_disconnects;
1621 for (i = 0; i < vec_len (pending_disconnects); i++)
1623 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1624 tcp_disconnect_pending_off (tc);
1625 session_transport_closing_notify (&tc->connection);
1627 _vec_len (wrk->pending_disconnects) = 0;
1631 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1634 /* Reject out-of-order fins */
1635 if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt)
1638 /* Account for the FIN and send ack */
1640 tcp_program_ack (tc);
1641 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1642 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1643 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1644 tcp_program_disconnect (wrk, tc);
1645 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1646 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1647 *error = TCP_ERROR_FIN_RCVD;
1650 #ifndef CLIB_MARCH_VARIANT
1652 tcp_sack_vector_is_sane (sack_block_t * sacks)
1655 for (i = 1; i < vec_len (sacks); i++)
1657 if (sacks[i - 1].end == sacks[i].start)
1664 * Build SACK list as per RFC2018.
1666 * Makes sure the first block contains the segment that generated the current
1667 * ACK and the following ones are the ones most recently reported in SACK
1670 * @param tc TCP connection for which the SACK list is updated
1671 * @param start Start sequence number of the newest SACK block
1672 * @param end End sequence of the newest SACK block
1675 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1677 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1680 /* If the first segment is ooo add it to the list. Last write might've moved
1681 * rcv_nxt over the first segment. */
1682 if (seq_lt (tc->rcv_nxt, start))
1684 vec_add2 (new_list, block, 1);
1685 block->start = start;
1689 /* Find the blocks still worth keeping. */
1690 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1692 /* Discard if rcv_nxt advanced beyond current block */
1693 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1696 /* Merge or drop if segment overlapped by the new segment */
1697 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1698 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1700 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1701 new_list[0].start = tc->snd_sacks[i].start;
1702 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1703 new_list[0].end = tc->snd_sacks[i].end;
1707 /* Save to new SACK list if we have space. */
1708 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1709 vec_add1 (new_list, tc->snd_sacks[i]);
1712 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1714 /* Replace old vector with new one */
1715 vec_reset_length (tc->snd_sacks);
1716 tc->snd_sacks_fl = tc->snd_sacks;
1717 tc->snd_sacks = new_list;
1719 /* Segments should not 'touch' */
1720 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1724 tcp_sack_list_bytes (tcp_connection_t * tc)
1727 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1728 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1731 #endif /* CLIB_MARCH_VARIANT */
1733 /** Enqueue data for delivery to application */
1735 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1738 int written, error = TCP_ERROR_ENQUEUED;
1740 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1742 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1743 1 /* queue event */ , 1);
1745 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1747 /* Update rcv_nxt */
1748 if (PREDICT_TRUE (written == data_len))
1750 tc->rcv_nxt += written;
1752 /* If more data written than expected, account for out-of-order bytes. */
1753 else if (written > data_len)
1755 tc->rcv_nxt += written;
1756 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1758 else if (written > 0)
1760 /* We've written something but FIFO is probably full now */
1761 tc->rcv_nxt += written;
1762 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1766 return TCP_ERROR_FIFO_FULL;
1769 /* Update SACK list if need be */
1770 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1772 /* Remove SACK blocks that have been delivered */
1773 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1779 /** Enqueue out-of-order data */
1781 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1787 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1790 /* Enqueue out-of-order data with relative offset */
1791 rv = session_enqueue_stream_connection (&tc->connection, b,
1792 vnet_buffer (b)->tcp.seq_number -
1793 tc->rcv_nxt, 0 /* queue event */ ,
1796 /* Nothing written */
1799 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1800 return TCP_ERROR_FIFO_FULL;
1803 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1805 /* Update SACK list if in use */
1806 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1808 ooo_segment_t *newest;
1811 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1813 /* Get the newest segment from the fifo */
1814 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1817 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1818 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1819 start = tc->rcv_nxt + offset;
1820 end = start + ooo_segment_length (s0->rx_fifo, newest);
1821 tcp_update_sack_list (tc, start, end);
1822 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1823 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1827 return TCP_ERROR_ENQUEUED_OOO;
1831 * Check if ACK could be delayed. If ack can be delayed, it should return
1832 * true for a full frame. If we're always acking return 0.
1835 tcp_can_delack (tcp_connection_t * tc)
1837 /* Send ack if ... */
1839 /* just sent a rcv wnd 0
1840 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1841 /* constrained to send ack */
1842 || (tc->flags & TCP_CONN_SNDACK) != 0
1843 /* we're almost out of tx wnd */
1844 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1851 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1853 u32 discard, first = b->current_length;
1854 vlib_main_t *vm = vlib_get_main ();
1856 /* Handle multi-buffer segments */
1857 if (n_bytes_to_drop > b->current_length)
1859 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1863 discard = clib_min (n_bytes_to_drop, b->current_length);
1864 vlib_buffer_advance (b, discard);
1865 b = vlib_get_buffer (vm, b->next_buffer);
1866 n_bytes_to_drop -= discard;
1868 while (n_bytes_to_drop);
1869 if (n_bytes_to_drop > first)
1870 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1873 vlib_buffer_advance (b, n_bytes_to_drop);
1874 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1879 * Receive buffer for connection and handle acks
1881 * It handles both in order or out-of-order data.
1884 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1887 u32 error, n_bytes_to_drop, n_data_bytes;
1889 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1890 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1891 ASSERT (n_data_bytes);
1893 /* Handle out-of-order data */
1894 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1896 /* Old sequence numbers allowed through because they overlapped
1898 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1900 /* Completely in the past (possible retransmit). Ack
1901 * retransmissions since we may not have any data to send */
1902 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1904 tcp_program_ack (tc);
1905 error = TCP_ERROR_SEGMENT_OLD;
1909 /* Chop off the bytes in the past and see if what is left
1910 * can be enqueued in order */
1911 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1912 n_data_bytes -= n_bytes_to_drop;
1913 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1914 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1916 error = TCP_ERROR_SEGMENT_OLD;
1922 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1923 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1924 tcp_program_dupack (tc);
1925 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1931 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1932 * segments can be enqueued after fifo tail offset changes. */
1933 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1934 if (tcp_can_delack (tc))
1936 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1937 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1941 tcp_program_ack (tc);
1949 tcp_header_t tcp_header;
1950 tcp_connection_t tcp_connection;
1954 format_tcp_rx_trace (u8 * s, va_list * args)
1956 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1957 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1958 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1959 u32 indent = format_get_indent (s);
1961 s = format (s, "%U\n%U%U",
1962 format_tcp_header, &t->tcp_header, 128,
1963 format_white_space, indent,
1964 format_tcp_connection, &t->tcp_connection, 1);
1970 format_tcp_rx_trace_short (u8 * s, va_list * args)
1972 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1973 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1974 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1976 s = format (s, "%d -> %d (%U)",
1977 clib_net_to_host_u16 (t->tcp_header.dst_port),
1978 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1979 t->tcp_connection.state);
1985 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1986 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1990 clib_memcpy_fast (&t0->tcp_connection, tc0,
1991 sizeof (t0->tcp_connection));
1995 th0 = tcp_buffer_hdr (b0);
1997 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2001 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2002 vlib_frame_t * frame, u8 is_ip4)
2006 n_left = frame->n_vectors;
2007 from = vlib_frame_vector_args (frame);
2011 tcp_connection_t *tc0;
2018 b0 = vlib_get_buffer (vm, bi0);
2020 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2022 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2023 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2025 th0 = tcp_buffer_hdr (b0);
2026 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2035 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2036 u8 is_ip4, u32 evt, u32 val)
2039 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2041 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2044 #define tcp_maybe_inc_counter(node_id, err, count) \
2046 if (next0 != tcp_next_drop (is_ip4)) \
2047 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2048 tcp6_##node_id##_node.index, is_ip4, err, \
2051 #define tcp_inc_counter(node_id, err, count) \
2052 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2053 tcp6_##node_id##_node.index, is_ip4, \
2055 #define tcp_maybe_inc_err_counter(cnts, err) \
2057 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2059 #define tcp_inc_err_counter(cnts, err, val) \
2063 #define tcp_store_err_counters(node_id, cnts) \
2066 for (i = 0; i < TCP_N_ERROR; i++) \
2068 tcp_inc_counter(node_id, i, cnts[i]); \
2073 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2074 vlib_frame_t * frame, int is_ip4)
2076 u32 thread_index = vm->thread_index, errors = 0;
2077 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2078 u32 n_left_from, *from, *first_buffer;
2079 u16 err_counters[TCP_N_ERROR] = { 0 };
2081 if (node->flags & VLIB_NODE_FLAG_TRACE)
2082 tcp_established_trace_frame (vm, node, frame, is_ip4);
2084 first_buffer = from = vlib_frame_vector_args (frame);
2085 n_left_from = frame->n_vectors;
2087 while (n_left_from > 0)
2089 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2092 tcp_connection_t *tc0;
2094 if (n_left_from > 1)
2097 pb = vlib_get_buffer (vm, from[1]);
2098 vlib_prefetch_buffer_header (pb, LOAD);
2099 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2106 b0 = vlib_get_buffer (vm, bi0);
2107 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2110 if (PREDICT_FALSE (tc0 == 0))
2112 error0 = TCP_ERROR_INVALID_CONNECTION;
2116 th0 = tcp_buffer_hdr (b0);
2118 /* TODO header prediction fast path */
2120 /* 1-4: check SEQ, RST, SYN */
2121 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2123 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2127 /* 5: check the ACK field */
2128 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2131 /* 6: check the URG bit TODO */
2133 /* 7: process the segment text */
2134 if (vnet_buffer (b0)->tcp.data_len)
2135 error0 = tcp_segment_rcv (wrk, tc0, b0);
2137 /* 8: check the FIN bit */
2138 if (PREDICT_FALSE (tcp_is_fin (th0)))
2139 tcp_rcv_fin (wrk, tc0, b0, &error0);
2142 tcp_inc_err_counter (err_counters, error0, 1);
2145 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2147 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2148 tcp_store_err_counters (established, err_counters);
2149 tcp_handle_postponed_dequeues (wrk);
2150 tcp_handle_disconnects (wrk);
2151 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2153 return frame->n_vectors;
2156 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2157 vlib_node_runtime_t * node,
2158 vlib_frame_t * from_frame)
2160 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2163 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2164 vlib_node_runtime_t * node,
2165 vlib_frame_t * from_frame)
2167 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2171 VLIB_REGISTER_NODE (tcp4_established_node) =
2173 .name = "tcp4-established",
2174 /* Takes a vector of packets. */
2175 .vector_size = sizeof (u32),
2176 .n_errors = TCP_N_ERROR,
2177 .error_strings = tcp_error_strings,
2178 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2181 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2182 foreach_tcp_state_next
2185 .format_trace = format_tcp_rx_trace_short,
2190 VLIB_REGISTER_NODE (tcp6_established_node) =
2192 .name = "tcp6-established",
2193 /* Takes a vector of packets. */
2194 .vector_size = sizeof (u32),
2195 .n_errors = TCP_N_ERROR,
2196 .error_strings = tcp_error_strings,
2197 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2200 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2201 foreach_tcp_state_next
2204 .format_trace = format_tcp_rx_trace_short,
2210 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2212 transport_connection_t *tmp = 0;
2219 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2222 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2223 && (tc->state == TCP_STATE_LISTEN
2224 || tc->c_rmt_port == hdr->src_port));
2228 handle = session_lookup_half_open_handle (&tc->connection);
2229 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2230 tc->c_proto, tc->c_is_ip4);
2234 if (tmp->lcl_port == hdr->dst_port
2235 && tmp->rmt_port == hdr->src_port)
2237 TCP_DBG ("half-open is valid!");
2245 * Lookup transport connection
2247 static tcp_connection_t *
2248 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2252 transport_connection_t *tconn;
2253 tcp_connection_t *tc;
2258 ip4 = vlib_buffer_get_current (b);
2259 tcp = ip4_next_header (ip4);
2260 tconn = session_lookup_connection_wt4 (fib_index,
2265 TRANSPORT_PROTO_TCP,
2266 thread_index, &is_filtered);
2267 tc = tcp_get_connection_from_transport (tconn);
2268 ASSERT (tcp_lookup_is_valid (tc, tcp));
2273 ip6 = vlib_buffer_get_current (b);
2274 tcp = ip6_next_header (ip6);
2275 tconn = session_lookup_connection_wt6 (fib_index,
2280 TRANSPORT_PROTO_TCP,
2281 thread_index, &is_filtered);
2282 tc = tcp_get_connection_from_transport (tconn);
2283 ASSERT (tcp_lookup_is_valid (tc, tcp));
2289 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2290 vlib_frame_t * from_frame, int is_ip4)
2292 tcp_main_t *tm = vnet_get_tcp_main ();
2293 u32 n_left_from, *from, *first_buffer, errors = 0;
2294 u32 my_thread_index = vm->thread_index;
2295 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2297 from = first_buffer = vlib_frame_vector_args (from_frame);
2298 n_left_from = from_frame->n_vectors;
2300 while (n_left_from > 0)
2302 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2303 tcp_connection_t *tc0, *new_tc0;
2304 tcp_header_t *tcp0 = 0;
2312 b0 = vlib_get_buffer (vm, bi0);
2314 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2315 if (PREDICT_FALSE (tc0 == 0))
2317 error0 = TCP_ERROR_INVALID_CONNECTION;
2321 /* Half-open completed recently but the connection was't removed
2322 * yet by the owning thread */
2323 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2325 /* Make sure the connection actually exists */
2326 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2327 my_thread_index, is_ip4));
2328 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2332 ack0 = vnet_buffer (b0)->tcp.ack_number;
2333 seq0 = vnet_buffer (b0)->tcp.seq_number;
2334 tcp0 = tcp_buffer_hdr (b0);
2336 /* Crude check to see if the connection handle does not match
2337 * the packet. Probably connection just switched to established */
2338 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2339 || tcp0->src_port != tc0->c_rmt_port))
2341 error0 = TCP_ERROR_INVALID_CONNECTION;
2345 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2346 && !tcp_syn (tcp0)))
2348 error0 = TCP_ERROR_SEGMENT_INVALID;
2352 /* SYNs consume sequence numbers */
2353 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2356 * 1. check the ACK bit
2360 * If the ACK bit is set
2361 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2362 * the RST bit is set, if so drop the segment and return)
2363 * <SEQ=SEG.ACK><CTL=RST>
2364 * and discard the segment. Return.
2365 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2369 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2371 if (!tcp_rst (tcp0))
2372 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2373 error0 = TCP_ERROR_RCV_WND;
2377 /* Make sure ACK is valid */
2378 if (seq_gt (tc0->snd_una, ack0))
2380 error0 = TCP_ERROR_ACK_INVALID;
2386 * 2. check the RST bit
2391 /* If ACK is acceptable, signal client that peer is not
2392 * willing to accept connection and drop connection*/
2394 tcp_connection_reset (tc0);
2395 error0 = TCP_ERROR_RST_RCVD;
2400 * 3. check the security and precedence (skipped)
2404 * 4. check the SYN bit
2407 /* No SYN flag. Drop. */
2408 if (!tcp_syn (tcp0))
2410 error0 = TCP_ERROR_SEGMENT_INVALID;
2415 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2417 error0 = TCP_ERROR_OPTIONS;
2421 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2422 * current thread pool. */
2423 pool_get (tm->connections[my_thread_index], new_tc0);
2424 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2425 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2426 new_tc0->c_thread_index = my_thread_index;
2427 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2428 new_tc0->irs = seq0;
2429 new_tc0->timers[TCP_TIMER_ESTABLISH_AO] = TCP_TIMER_HANDLE_INVALID;
2430 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2431 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2433 /* If this is not the owning thread, wait for syn retransmit to
2434 * expire and cleanup then */
2435 if (tcp_half_open_connection_cleanup (tc0))
2436 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2438 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2440 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2441 new_tc0->tsval_recent_age = tcp_time_now ();
2444 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2445 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2447 new_tc0->rcv_wscale = 0;
2449 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2450 << new_tc0->snd_wscale;
2451 new_tc0->snd_wl1 = seq0;
2452 new_tc0->snd_wl2 = ack0;
2454 tcp_connection_init_vars (new_tc0);
2456 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2457 if (PREDICT_TRUE (tcp_ack (tcp0)))
2459 /* Our SYN is ACKed: we have iss < ack = snd_una */
2461 /* TODO Dequeue acknowledged segments if we support Fast Open */
2462 new_tc0->snd_una = ack0;
2463 new_tc0->state = TCP_STATE_ESTABLISHED;
2465 /* Make sure las is initialized for the wnd computation */
2466 new_tc0->rcv_las = new_tc0->rcv_nxt;
2468 /* Notify app that we have connection. If session layer can't
2469 * allocate session send reset */
2470 if (session_stream_connect_notify (&new_tc0->connection, 0))
2472 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2473 tcp_connection_cleanup (new_tc0);
2474 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2478 new_tc0->tx_fifo_size =
2479 transport_tx_fifo_size (&new_tc0->connection);
2480 /* Update rtt with the syn-ack sample */
2481 tcp_estimate_initial_rtt (new_tc0);
2482 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2483 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2485 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2488 new_tc0->state = TCP_STATE_SYN_RCVD;
2490 /* Notify app that we have connection */
2491 if (session_stream_connect_notify (&new_tc0->connection, 0))
2493 tcp_connection_cleanup (new_tc0);
2494 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2495 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2496 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2500 new_tc0->tx_fifo_size =
2501 transport_tx_fifo_size (&new_tc0->connection);
2502 new_tc0->rtt_ts = 0;
2503 tcp_init_snd_vars (new_tc0);
2504 tcp_send_synack (new_tc0);
2505 error0 = TCP_ERROR_SYNS_RCVD;
2509 /* Read data, if any */
2510 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2512 clib_warning ("rcvd data in syn-sent");
2513 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2514 if (error0 == TCP_ERROR_ACK_OK)
2515 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2519 tcp_program_ack (new_tc0);
2524 tcp_inc_counter (syn_sent, error0, 1);
2525 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2527 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2528 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2529 clib_memcpy_fast (&t0->tcp_connection, tc0,
2530 sizeof (t0->tcp_connection));
2534 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2536 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2537 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2539 return from_frame->n_vectors;
2542 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2543 vlib_node_runtime_t * node,
2544 vlib_frame_t * from_frame)
2546 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2549 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2550 vlib_node_runtime_t * node,
2551 vlib_frame_t * from_frame)
2553 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2557 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2559 .name = "tcp4-syn-sent",
2560 /* Takes a vector of packets. */
2561 .vector_size = sizeof (u32),
2562 .n_errors = TCP_N_ERROR,
2563 .error_strings = tcp_error_strings,
2564 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2567 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2568 foreach_tcp_state_next
2571 .format_trace = format_tcp_rx_trace_short,
2576 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2578 .name = "tcp6-syn-sent",
2579 /* Takes a vector of packets. */
2580 .vector_size = sizeof (u32),
2581 .n_errors = TCP_N_ERROR,
2582 .error_strings = tcp_error_strings,
2583 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2586 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2587 foreach_tcp_state_next
2590 .format_trace = format_tcp_rx_trace_short,
2595 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2596 * as per RFC793 p. 64
2599 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2600 vlib_frame_t * from_frame, int is_ip4)
2602 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2603 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2604 u32 n_left_from, *from, max_dequeue;
2606 from = first_buffer = vlib_frame_vector_args (from_frame);
2607 n_left_from = from_frame->n_vectors;
2609 while (n_left_from > 0)
2611 u32 bi0, error0 = TCP_ERROR_NONE;
2612 tcp_header_t *tcp0 = 0;
2613 tcp_connection_t *tc0;
2621 b0 = vlib_get_buffer (vm, bi0);
2622 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2624 if (PREDICT_FALSE (tc0 == 0))
2626 error0 = TCP_ERROR_INVALID_CONNECTION;
2630 tcp0 = tcp_buffer_hdr (b0);
2631 is_fin0 = tcp_is_fin (tcp0);
2635 tcp_connection_t *tmp;
2636 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2638 if (tmp->state != tc0->state)
2640 if (tc0->state != TCP_STATE_CLOSED)
2641 clib_warning ("state changed");
2647 * Special treatment for CLOSED
2649 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2651 error0 = TCP_ERROR_CONNECTION_CLOSED;
2656 * For all other states (except LISTEN)
2659 /* 1-4: check SEQ, RST, SYN */
2660 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2663 /* 5: check the ACK field */
2666 case TCP_STATE_SYN_RCVD:
2668 /* Make sure the segment is exactly right */
2669 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2671 tcp_connection_reset (tc0);
2672 error0 = TCP_ERROR_SEGMENT_INVALID;
2677 * If the segment acknowledgment is not acceptable, form a
2679 * <SEQ=SEG.ACK><CTL=RST>
2682 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2684 tcp_connection_reset (tc0);
2688 /* Update rtt and rto */
2689 tcp_estimate_initial_rtt (tc0);
2691 /* Switch state to ESTABLISHED */
2692 tc0->state = TCP_STATE_ESTABLISHED;
2693 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2695 /* Initialize session variables */
2696 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2697 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2698 << tc0->rcv_opts.wscale;
2699 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2700 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2702 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2703 tcp_retransmit_timer_reset (tc0);
2704 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2705 if (session_stream_accept_notify (&tc0->connection))
2707 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2708 tcp_connection_reset (tc0);
2711 error0 = TCP_ERROR_ACK_OK;
2713 case TCP_STATE_ESTABLISHED:
2714 /* We can get packets in established state here because they
2715 * were enqueued before state change */
2716 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2720 case TCP_STATE_FIN_WAIT_1:
2721 /* In addition to the processing for the ESTABLISHED state, if
2722 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2723 * continue processing in that state. */
2724 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2727 /* Still have to send the FIN */
2728 if (tc0->flags & TCP_CONN_FINPNDG)
2730 /* TX fifo finally drained */
2731 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2732 if (max_dequeue <= tc0->burst_acked)
2734 /* If a fin was received and data was acked extend wait */
2735 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
2736 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2737 TCP_CLOSEWAIT_TIME);
2739 /* If FIN is ACKed */
2740 else if (tc0->snd_una == tc0->snd_nxt)
2742 /* Stop all retransmit timers because we have nothing more
2744 tcp_connection_timers_reset (tc0);
2746 /* We already have a FIN but didn't transition to CLOSING
2747 * because of outstanding tx data. Close the connection. */
2748 if (tc0->flags & TCP_CONN_FINRCVD)
2750 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2751 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2752 session_transport_closed_notify (&tc0->connection);
2756 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2757 /* Enable waitclose because we're willing to wait for peer's
2758 * FIN but not indefinitely. */
2759 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2761 /* Don't try to deq the FIN acked */
2762 if (tc0->burst_acked > 1)
2763 session_tx_fifo_dequeue_drop (&tc0->connection,
2764 tc0->burst_acked - 1);
2765 tc0->burst_acked = 0;
2768 case TCP_STATE_FIN_WAIT_2:
2769 /* In addition to the processing for the ESTABLISHED state, if
2770 * the retransmission queue is empty, the user's CLOSE can be
2771 * acknowledged ("ok") but do not delete the TCB. */
2772 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2774 tc0->burst_acked = 0;
2776 case TCP_STATE_CLOSE_WAIT:
2777 /* Do the same processing as for the ESTABLISHED state. */
2778 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2781 if (!(tc0->flags & TCP_CONN_FINPNDG))
2784 /* Still have outstanding tx data */
2785 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2786 if (max_dequeue > tc0->burst_acked)
2790 tcp_connection_timers_reset (tc0);
2791 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2792 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2794 case TCP_STATE_CLOSING:
2795 /* In addition to the processing for the ESTABLISHED state, if
2796 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2797 * otherwise ignore the segment. */
2798 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2801 if (tc0->snd_una != tc0->snd_nxt)
2804 tcp_connection_timers_reset (tc0);
2805 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2806 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2807 session_transport_closed_notify (&tc0->connection);
2811 case TCP_STATE_LAST_ACK:
2812 /* The only thing that [should] arrive in this state is an
2813 * acknowledgment of our FIN. If our FIN is now acknowledged,
2814 * delete the TCB, enter the CLOSED state, and return. */
2816 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2819 /* Apparently our ACK for the peer's FIN was lost */
2820 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2826 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2827 session_transport_closed_notify (&tc0->connection);
2829 /* Don't free the connection from the data path since
2830 * we can't ensure that we have no packets already enqueued
2831 * to output. Rely instead on the waitclose timer */
2832 tcp_connection_timers_reset (tc0);
2833 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2838 case TCP_STATE_TIME_WAIT:
2839 /* The only thing that can arrive in this state is a
2840 * retransmission of the remote FIN. Acknowledge it, and restart
2841 * the 2 MSL timeout. */
2843 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2849 tcp_program_ack (tc0);
2850 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2858 /* 6: check the URG bit TODO */
2860 /* 7: process the segment text */
2863 case TCP_STATE_ESTABLISHED:
2864 case TCP_STATE_FIN_WAIT_1:
2865 case TCP_STATE_FIN_WAIT_2:
2866 if (vnet_buffer (b0)->tcp.data_len)
2867 error0 = tcp_segment_rcv (wrk, tc0, b0);
2869 case TCP_STATE_CLOSE_WAIT:
2870 case TCP_STATE_CLOSING:
2871 case TCP_STATE_LAST_ACK:
2872 case TCP_STATE_TIME_WAIT:
2873 /* This should not occur, since a FIN has been received from the
2874 * remote side. Ignore the segment text. */
2878 /* 8: check the FIN bit */
2882 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2886 case TCP_STATE_ESTABLISHED:
2887 /* Account for the FIN and send ack */
2889 tcp_program_ack (tc0);
2890 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2891 tcp_program_disconnect (wrk, tc0);
2892 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2894 case TCP_STATE_SYN_RCVD:
2895 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2896 * notified yet, set a cleanup timer instead of relying on
2897 * disconnect notify and the implicit close call. */
2898 tcp_connection_timers_reset (tc0);
2901 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2902 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2904 case TCP_STATE_CLOSE_WAIT:
2905 case TCP_STATE_CLOSING:
2906 case TCP_STATE_LAST_ACK:
2909 case TCP_STATE_FIN_WAIT_1:
2912 if (tc0->flags & TCP_CONN_FINPNDG)
2914 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
2915 * sending it. Since we already received a fin, do not wait
2917 tc0->flags |= TCP_CONN_FINRCVD;
2918 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2922 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
2923 tcp_program_ack (tc0);
2924 /* Wait for ACK for our FIN but not forever */
2925 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2928 case TCP_STATE_FIN_WAIT_2:
2929 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2931 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2932 tcp_connection_timers_reset (tc0);
2933 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2934 tcp_program_ack (tc0);
2935 session_transport_closed_notify (&tc0->connection);
2937 case TCP_STATE_TIME_WAIT:
2938 /* Remain in the TIME-WAIT state. Restart the time-wait
2941 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2944 error0 = TCP_ERROR_FIN_RCVD;
2948 tcp_inc_counter (rcv_process, error0, 1);
2949 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2951 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2952 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2956 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2958 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
2959 tcp_handle_postponed_dequeues (wrk);
2960 tcp_handle_disconnects (wrk);
2961 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2963 return from_frame->n_vectors;
2966 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
2967 vlib_node_runtime_t * node,
2968 vlib_frame_t * from_frame)
2970 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2973 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
2974 vlib_node_runtime_t * node,
2975 vlib_frame_t * from_frame)
2977 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2981 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2983 .name = "tcp4-rcv-process",
2984 /* Takes a vector of packets. */
2985 .vector_size = sizeof (u32),
2986 .n_errors = TCP_N_ERROR,
2987 .error_strings = tcp_error_strings,
2988 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2991 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2992 foreach_tcp_state_next
2995 .format_trace = format_tcp_rx_trace_short,
3000 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3002 .name = "tcp6-rcv-process",
3003 /* Takes a vector of packets. */
3004 .vector_size = sizeof (u32),
3005 .n_errors = TCP_N_ERROR,
3006 .error_strings = tcp_error_strings,
3007 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3010 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3011 foreach_tcp_state_next
3014 .format_trace = format_tcp_rx_trace_short,
3019 * LISTEN state processing as per RFC 793 p. 65
3022 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3023 vlib_frame_t * from_frame, int is_ip4)
3025 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3026 u32 my_thread_index = vm->thread_index;
3028 from = first_buffer = vlib_frame_vector_args (from_frame);
3029 n_left_from = from_frame->n_vectors;
3031 while (n_left_from > 0)
3036 tcp_header_t *th0 = 0;
3037 tcp_connection_t *lc0;
3040 tcp_connection_t *child0;
3041 u32 error0 = TCP_ERROR_NONE;
3047 b0 = vlib_get_buffer (vm, bi0);
3048 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3052 ip40 = vlib_buffer_get_current (b0);
3053 th0 = ip4_next_header (ip40);
3057 ip60 = vlib_buffer_get_current (b0);
3058 th0 = ip6_next_header (ip60);
3061 /* Create child session. For syn-flood protection use filter */
3063 /* 1. first check for an RST: handled in dispatch */
3064 /* if (tcp_rst (th0))
3068 /* 2. second check for an ACK: handled in dispatch */
3069 /* if (tcp_ack (th0))
3071 tcp_send_reset (b0, is_ip4);
3076 /* 3. check for a SYN (did that already) */
3078 /* Make sure connection wasn't just created */
3079 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3081 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3083 error0 = TCP_ERROR_CREATE_EXISTS;
3087 /* Create child session and send SYN-ACK */
3088 child0 = tcp_connection_alloc (my_thread_index);
3089 child0->c_lcl_port = th0->dst_port;
3090 child0->c_rmt_port = th0->src_port;
3091 child0->c_is_ip4 = is_ip4;
3092 child0->state = TCP_STATE_SYN_RCVD;
3093 child0->c_fib_index = lc0->c_fib_index;
3097 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3098 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3102 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3103 sizeof (ip6_address_t));
3104 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3105 sizeof (ip6_address_t));
3108 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3110 error0 = TCP_ERROR_OPTIONS;
3111 tcp_connection_free (child0);
3115 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3116 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3117 child0->rcv_las = child0->rcv_nxt;
3118 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3120 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3121 * segments are used to initialize PAWS. */
3122 if (tcp_opts_tstamp (&child0->rcv_opts))
3124 child0->tsval_recent = child0->rcv_opts.tsval;
3125 child0->tsval_recent_age = tcp_time_now ();
3128 if (tcp_opts_wscale (&child0->rcv_opts))
3129 child0->snd_wscale = child0->rcv_opts.wscale;
3131 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3132 << child0->snd_wscale;
3133 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3134 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3136 tcp_connection_init_vars (child0);
3137 child0->rto = TCP_RTO_MIN;
3139 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3140 lc0->c_thread_index, 0 /* notify */ ))
3142 tcp_connection_cleanup (child0);
3143 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3147 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3148 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3149 tcp_send_synack (child0);
3150 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3154 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3156 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3157 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3158 clib_memcpy_fast (&t0->tcp_connection, lc0,
3159 sizeof (t0->tcp_connection));
3162 n_syns += (error0 == TCP_ERROR_NONE);
3165 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3166 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3168 return from_frame->n_vectors;
3171 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3172 vlib_frame_t * from_frame)
3174 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3177 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3178 vlib_frame_t * from_frame)
3180 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3184 VLIB_REGISTER_NODE (tcp4_listen_node) =
3186 .name = "tcp4-listen",
3187 /* Takes a vector of packets. */
3188 .vector_size = sizeof (u32),
3189 .n_errors = TCP_N_ERROR,
3190 .error_strings = tcp_error_strings,
3191 .n_next_nodes = TCP_LISTEN_N_NEXT,
3194 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3195 foreach_tcp_state_next
3198 .format_trace = format_tcp_rx_trace_short,
3203 VLIB_REGISTER_NODE (tcp6_listen_node) =
3205 .name = "tcp6-listen",
3206 /* Takes a vector of packets. */
3207 .vector_size = sizeof (u32),
3208 .n_errors = TCP_N_ERROR,
3209 .error_strings = tcp_error_strings,
3210 .n_next_nodes = TCP_LISTEN_N_NEXT,
3213 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3214 foreach_tcp_state_next
3217 .format_trace = format_tcp_rx_trace_short,
3221 typedef enum _tcp_input_next
3223 TCP_INPUT_NEXT_DROP,
3224 TCP_INPUT_NEXT_LISTEN,
3225 TCP_INPUT_NEXT_RCV_PROCESS,
3226 TCP_INPUT_NEXT_SYN_SENT,
3227 TCP_INPUT_NEXT_ESTABLISHED,
3228 TCP_INPUT_NEXT_RESET,
3229 TCP_INPUT_NEXT_PUNT,
3233 #define foreach_tcp4_input_next \
3234 _ (DROP, "ip4-drop") \
3235 _ (LISTEN, "tcp4-listen") \
3236 _ (RCV_PROCESS, "tcp4-rcv-process") \
3237 _ (SYN_SENT, "tcp4-syn-sent") \
3238 _ (ESTABLISHED, "tcp4-established") \
3239 _ (RESET, "tcp4-reset") \
3240 _ (PUNT, "ip4-punt")
3242 #define foreach_tcp6_input_next \
3243 _ (DROP, "ip6-drop") \
3244 _ (LISTEN, "tcp6-listen") \
3245 _ (RCV_PROCESS, "tcp6-rcv-process") \
3246 _ (SYN_SENT, "tcp6-syn-sent") \
3247 _ (ESTABLISHED, "tcp6-established") \
3248 _ (RESET, "tcp6-reset") \
3249 _ (PUNT, "ip6-punt")
3251 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3254 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3255 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3257 tcp_connection_t *tc;
3262 for (i = 0; i < n_bufs; i++)
3264 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3266 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3267 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3269 tcp = vlib_buffer_get_current (bs[i]);
3270 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3276 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3278 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3280 *next = TCP_INPUT_NEXT_DROP;
3282 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3284 *next = TCP_INPUT_NEXT_PUNT;
3285 *error = TCP_ERROR_PUNT;
3289 *next = TCP_INPUT_NEXT_RESET;
3290 *error = TCP_ERROR_NO_LISTENER;
3294 always_inline tcp_connection_t *
3295 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3296 u8 is_ip4, u8 is_nolookup)
3298 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3299 int n_advance_bytes, n_data_bytes;
3300 transport_connection_t *tc;
3306 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3307 int ip_hdr_bytes = ip4_header_bytes (ip4);
3308 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3310 *error = TCP_ERROR_LENGTH;
3313 tcp = ip4_next_header (ip4);
3314 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3315 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3316 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3318 /* Length check. Checksum computed by ipx_local no need to compute again */
3319 if (PREDICT_FALSE (n_data_bytes < 0))
3321 *error = TCP_ERROR_LENGTH;
3326 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3327 &ip4->src_address, tcp->dst_port,
3329 TRANSPORT_PROTO_TCP, thread_index,
3334 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3335 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3337 *error = TCP_ERROR_LENGTH;
3340 tcp = ip6_next_header (ip6);
3341 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3342 n_advance_bytes = tcp_header_bytes (tcp);
3343 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3345 n_advance_bytes += sizeof (ip6[0]);
3347 if (PREDICT_FALSE (n_data_bytes < 0))
3349 *error = TCP_ERROR_LENGTH;
3356 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3358 ip4_main_t *im = &ip4_main;
3359 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3360 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3363 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3365 tcp->dst_port, tcp->src_port,
3366 TRANSPORT_PROTO_TCP,
3367 thread_index, &result);
3373 (transport_connection_t *) tcp_connection_get (vnet_buffer (b)->
3374 tcp.connection_index,
3377 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3378 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3379 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3380 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3381 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3383 vnet_buffer (b)->tcp.flags = 0;
3385 *error = result ? TCP_ERROR_NONE + result : *error;
3387 return tcp_get_connection_from_transport (tc);
3391 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3392 vlib_buffer_t * b, u16 * next, u32 * error)
3397 tcp = tcp_buffer_hdr (b);
3398 flags = tcp->flags & filter_flags;
3399 *next = tm->dispatch_table[tc->state][flags].next;
3400 *error = tm->dispatch_table[tc->state][flags].error;
3402 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3403 || *next == TCP_INPUT_NEXT_RESET))
3405 /* Overload tcp flags to store state */
3406 tcp_state_t state = tc->state;
3407 vnet_buffer (b)->tcp.flags = tc->state;
3409 if (*error == TCP_ERROR_DISPATCH)
3410 clib_warning ("tcp conn %u disp error state %U flags %U",
3411 tc->c_c_index, format_tcp_state, state,
3412 format_tcp_flags, (int) flags);
3417 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3418 vlib_frame_t * frame, int is_ip4, u8 is_nolookup)
3420 u32 n_left_from, *from, thread_index = vm->thread_index;
3421 tcp_main_t *tm = vnet_get_tcp_main ();
3422 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3423 u16 nexts[VLIB_FRAME_SIZE], *next;
3425 tcp_set_time_now (tcp_get_worker (thread_index));
3427 from = vlib_frame_vector_args (frame);
3428 n_left_from = frame->n_vectors;
3429 vlib_get_buffers (vm, from, bufs, n_left_from);
3434 while (n_left_from >= 4)
3436 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3437 tcp_connection_t *tc0, *tc1;
3440 vlib_prefetch_buffer_header (b[2], STORE);
3441 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3443 vlib_prefetch_buffer_header (b[3], STORE);
3444 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3447 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3449 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3451 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4,
3454 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3456 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3457 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3459 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3460 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3462 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3463 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3467 if (PREDICT_TRUE (tc0 != 0))
3469 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3470 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3471 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3474 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3476 if (PREDICT_TRUE (tc1 != 0))
3478 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3479 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3480 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3483 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3490 while (n_left_from > 0)
3492 tcp_connection_t *tc0;
3493 u32 error0 = TCP_ERROR_NO_LISTENER;
3495 if (n_left_from > 1)
3497 vlib_prefetch_buffer_header (b[1], STORE);
3498 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3501 next[0] = TCP_INPUT_NEXT_DROP;
3502 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3504 if (PREDICT_TRUE (tc0 != 0))
3506 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3507 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3508 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3511 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3518 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3519 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3521 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3522 return frame->n_vectors;
3525 VLIB_NODE_FN (tcp4_input_nolookup_node) (vlib_main_t * vm,
3526 vlib_node_runtime_t * node,
3527 vlib_frame_t * from_frame)
3529 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3530 1 /* is_nolookup */ );
3533 VLIB_NODE_FN (tcp6_input_nolookup_node) (vlib_main_t * vm,
3534 vlib_node_runtime_t * node,
3535 vlib_frame_t * from_frame)
3537 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3538 1 /* is_nolookup */ );
3542 VLIB_REGISTER_NODE (tcp4_input_nolookup_node) =
3544 .name = "tcp4-input-nolookup",
3545 /* Takes a vector of packets. */
3546 .vector_size = sizeof (u32),
3547 .n_errors = TCP_N_ERROR,
3548 .error_strings = tcp_error_strings,
3549 .n_next_nodes = TCP_INPUT_N_NEXT,
3552 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3553 foreach_tcp4_input_next
3556 .format_buffer = format_tcp_header,
3557 .format_trace = format_tcp_rx_trace,
3562 VLIB_REGISTER_NODE (tcp6_input_nolookup_node) =
3564 .name = "tcp6-input-nolookup",
3565 /* Takes a vector of packets. */
3566 .vector_size = sizeof (u32),
3567 .n_errors = TCP_N_ERROR,
3568 .error_strings = tcp_error_strings,
3569 .n_next_nodes = TCP_INPUT_N_NEXT,
3572 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3573 foreach_tcp6_input_next
3576 .format_buffer = format_tcp_header,
3577 .format_trace = format_tcp_rx_trace,
3581 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3582 vlib_frame_t * from_frame)
3584 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3585 0 /* is_nolookup */ );
3588 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3589 vlib_frame_t * from_frame)
3591 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3592 0 /* is_nolookup */ );
3596 VLIB_REGISTER_NODE (tcp4_input_node) =
3598 .name = "tcp4-input",
3599 /* Takes a vector of packets. */
3600 .vector_size = sizeof (u32),
3601 .n_errors = TCP_N_ERROR,
3602 .error_strings = tcp_error_strings,
3603 .n_next_nodes = TCP_INPUT_N_NEXT,
3606 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3607 foreach_tcp4_input_next
3610 .format_buffer = format_tcp_header,
3611 .format_trace = format_tcp_rx_trace,
3616 VLIB_REGISTER_NODE (tcp6_input_node) =
3618 .name = "tcp6-input",
3619 /* Takes a vector of packets. */
3620 .vector_size = sizeof (u32),
3621 .n_errors = TCP_N_ERROR,
3622 .error_strings = tcp_error_strings,
3623 .n_next_nodes = TCP_INPUT_N_NEXT,
3626 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3627 foreach_tcp6_input_next
3630 .format_buffer = format_tcp_header,
3631 .format_trace = format_tcp_rx_trace,
3635 #ifndef CLIB_MARCH_VARIANT
3637 tcp_dispatch_table_init (tcp_main_t * tm)
3640 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3641 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3643 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3644 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3647 #define _(t,f,n,e) \
3649 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3650 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3653 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3654 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3655 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3656 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3657 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3658 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3659 TCP_ERROR_ACK_INVALID);
3660 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3661 TCP_ERROR_SEGMENT_INVALID);
3662 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3663 TCP_ERROR_SEGMENT_INVALID);
3664 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3665 TCP_ERROR_INVALID_CONNECTION);
3666 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3667 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3668 TCP_ERROR_SEGMENT_INVALID);
3669 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3670 TCP_ERROR_SEGMENT_INVALID);
3671 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3673 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3674 TCP_ERROR_SEGMENT_INVALID);
3675 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3676 TCP_ERROR_SEGMENT_INVALID);
3677 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3678 TCP_ERROR_SEGMENT_INVALID);
3679 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3680 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3681 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3682 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3683 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3684 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3686 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3687 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3689 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3691 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3692 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3693 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3694 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3696 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3698 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3699 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3700 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3702 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3703 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3704 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3705 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3706 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3707 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3708 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3709 /* SYN-ACK for a SYN */
3710 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3712 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3713 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3714 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3716 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3717 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3719 /* ACK for for established connection -> tcp-established. */
3720 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3721 /* FIN for for established connection -> tcp-established. */
3722 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3723 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3725 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3727 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3728 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3729 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3731 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3732 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3733 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3734 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3735 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3736 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3737 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3738 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3740 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3741 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3743 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3745 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3746 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3747 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3748 /* ACK or FIN-ACK to our FIN */
3749 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3750 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3752 /* FIN in reply to our FIN from the other side */
3753 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3754 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3755 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3757 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3758 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3759 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3760 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3761 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3762 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3763 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3765 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3766 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3767 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3768 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3770 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3772 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3773 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3774 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3775 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3777 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3778 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3779 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3780 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3782 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3784 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3785 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3786 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3787 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3789 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3790 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3792 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3794 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3795 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3796 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3798 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3799 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3800 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3801 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3802 /* FIN confirming that the peer (app) has closed */
3803 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3804 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3805 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3807 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3808 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3810 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3811 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3813 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3814 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3816 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3817 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3818 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3819 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3821 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3823 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3824 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3825 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3827 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3828 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3829 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3830 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3831 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3832 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3833 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3834 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3836 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3837 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3839 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3841 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3842 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3843 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3844 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3845 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3847 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3848 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3850 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3851 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3852 * incoming segment not containing a RST causes a RST to be sent in
3854 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3855 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3856 TCP_ERROR_CONNECTION_CLOSED);
3857 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3858 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3859 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3864 static clib_error_t *
3865 tcp_input_init (vlib_main_t * vm)
3867 clib_error_t *error = 0;
3868 tcp_main_t *tm = vnet_get_tcp_main ();
3870 if ((error = vlib_call_init_function (vm, tcp_init)))
3873 /* Initialize dispatch table. */
3874 tcp_dispatch_table_init (tm);
3879 VLIB_INIT_FUNCTION (tcp_input_init);
3881 #endif /* CLIB_MARCH_VARIANT */
3884 * fd.io coding-style-patch-verification: ON
3887 * eval: (c-set-style "gnu")