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/fib/ip4_fib.h>
18 #include <vnet/fib/ip6_fib.h>
19 #include <vnet/tcp/tcp_packet.h>
20 #include <vnet/tcp/tcp.h>
21 #include <vnet/session/session.h>
24 static char *tcp_error_strings[] = {
25 #define tcp_error(n,s) s,
26 #include <vnet/tcp/tcp_error.def>
30 /* All TCP nodes have the same outgoing arcs */
31 #define foreach_tcp_state_next \
32 _ (DROP4, "ip4-drop") \
33 _ (DROP6, "ip6-drop") \
34 _ (TCP4_OUTPUT, "tcp4-output") \
35 _ (TCP6_OUTPUT, "tcp6-output")
37 typedef enum _tcp_established_next
39 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
40 foreach_tcp_state_next
42 TCP_ESTABLISHED_N_NEXT,
43 } tcp_established_next_t;
45 typedef enum _tcp_rcv_process_next
47 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
48 foreach_tcp_state_next
50 TCP_RCV_PROCESS_N_NEXT,
51 } tcp_rcv_process_next_t;
53 typedef enum _tcp_syn_sent_next
55 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
56 foreach_tcp_state_next
59 } tcp_syn_sent_next_t;
61 typedef enum _tcp_listen_next
63 #define _(s,n) TCP_LISTEN_NEXT_##s,
64 foreach_tcp_state_next
69 /* Generic, state independent indices */
70 typedef enum _tcp_state_next
72 #define _(s,n) TCP_NEXT_##s,
73 foreach_tcp_state_next
78 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
79 : TCP_NEXT_TCP6_OUTPUT)
81 #define tcp_next_drop(is_ip4) (is_ip4 ? TCP_NEXT_DROP4 \
85 * Validate segment sequence number. As per RFC793:
87 * Segment Receive Test
89 * ------- ------- -------------------------------------------
90 * 0 0 SEG.SEQ = RCV.NXT
91 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
93 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
94 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
96 * This ultimately consists in checking if segment falls within the window.
97 * The one important difference compared to RFC793 is that we use rcv_las,
98 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
99 * peer's reference when computing our receive window.
102 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
103 * however, is too strict when we have retransmits. Instead we just check that
104 * the seq is not beyond the right edge and that the end of the segment is not
105 * less than the left edge.
107 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
108 * use rcv_nxt in the right edge window test instead of rcv_las.
112 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
114 return (seq_geq (end_seq, tc->rcv_las)
115 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
119 * Parse TCP header options.
121 * @param th TCP header
122 * @param to TCP options data structure to be populated
123 * @param is_syn set if packet is syn
124 * @return -1 if parsing failed
127 tcp_options_parse (tcp_header_t * th, tcp_options_t * to, u8 is_syn)
130 u8 opt_len, opts_len, kind;
134 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
135 data = (const u8 *) (th + 1);
137 /* Zero out all flags but those set in SYN */
138 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
139 | TCP_OPTS_FLAG_TSTAMP | TCP_OPTS_FLAG_MSS);
141 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
145 /* Get options length */
146 if (kind == TCP_OPTION_EOL)
148 else if (kind == TCP_OPTION_NOOP)
160 /* weird option length */
161 if (opt_len < 2 || opt_len > opts_len)
171 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
173 to->flags |= TCP_OPTS_FLAG_MSS;
174 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
177 case TCP_OPTION_WINDOW_SCALE:
180 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
182 to->flags |= TCP_OPTS_FLAG_WSCALE;
183 to->wscale = data[2];
184 if (to->wscale > TCP_MAX_WND_SCALE)
185 to->wscale = TCP_MAX_WND_SCALE;
188 case TCP_OPTION_TIMESTAMP:
190 to->flags |= TCP_OPTS_FLAG_TSTAMP;
191 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
192 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
194 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
195 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
198 case TCP_OPTION_SACK_PERMITTED:
201 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
202 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
204 case TCP_OPTION_SACK_BLOCK:
205 /* If SACK permitted was not advertised or a SYN, break */
206 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
209 /* If too short or not correctly formatted, break */
210 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
213 to->flags |= TCP_OPTS_FLAG_SACK;
214 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
215 vec_reset_length (to->sacks);
216 for (j = 0; j < to->n_sack_blocks; j++)
218 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
219 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
220 vec_add1 (to->sacks, b);
224 /* Nothing to see here */
232 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
233 * timestamp to echo and it's less than tsval_recent, drop segment
234 * but still send an ACK in order to retain TCP's mechanism for detecting
235 * and recovering from half-open connections
237 * Or at least that's what the theory says. It seems that this might not work
238 * very well with packet reordering and fast retransmit. XXX
241 tcp_segment_check_paws (tcp_connection_t * tc)
243 return tcp_opts_tstamp (&tc->rcv_opts)
244 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
248 * Update tsval recent
251 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
254 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
255 * of an incoming segment:
256 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
257 * then the TSval from the segment is copied to TS.Recent;
258 * otherwise, the TSval is ignored.
260 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
261 && seq_leq (tc->rcv_las, seq_end))
263 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
264 tc->tsval_recent = tc->rcv_opts.tsval;
265 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
270 tcp_handle_rst (tcp_connection_t * tc)
272 switch (tc->rst_state)
274 case TCP_STATE_SYN_RCVD:
275 /* Cleanup everything. App wasn't notified yet */
276 session_transport_delete_notify (&tc->connection);
277 tcp_connection_cleanup (tc);
279 case TCP_STATE_SYN_SENT:
280 session_stream_connect_notify (&tc->connection, 1 /* fail */ );
281 tcp_connection_cleanup (tc);
283 case TCP_STATE_ESTABLISHED:
284 session_transport_reset_notify (&tc->connection);
285 session_transport_closed_notify (&tc->connection);
287 case TCP_STATE_CLOSE_WAIT:
288 case TCP_STATE_FIN_WAIT_1:
289 case TCP_STATE_FIN_WAIT_2:
290 case TCP_STATE_CLOSING:
291 case TCP_STATE_LAST_ACK:
292 session_transport_closed_notify (&tc->connection);
294 case TCP_STATE_CLOSED:
295 case TCP_STATE_TIME_WAIT:
298 TCP_DBG ("reset state: %u", tc->state);
303 tcp_program_reset_ntf (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
305 if (!tcp_disconnect_pending (tc))
307 tc->rst_state = tc->state;
308 vec_add1 (wrk->pending_resets, tc->c_c_index);
309 tcp_disconnect_pending_on (tc);
314 * Handle reset packet
316 * Programs disconnect/reset notification that should be sent
317 * later by calling @ref tcp_handle_disconnects
320 tcp_rcv_rst (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
322 TCP_EVT (TCP_EVT_RST_RCVD, tc);
325 case TCP_STATE_SYN_RCVD:
326 tcp_program_reset_ntf (wrk, tc);
327 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
329 case TCP_STATE_SYN_SENT:
330 tcp_program_reset_ntf (wrk, tc);
331 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
333 case TCP_STATE_ESTABLISHED:
334 tcp_connection_timers_reset (tc);
335 /* Set the cleanup timer, in case the session layer/app don't
336 * cleanly close the connection */
337 tcp_timer_set (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
338 tcp_cong_recovery_off (tc);
339 tcp_program_reset_ntf (wrk, tc);
340 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
342 case TCP_STATE_CLOSE_WAIT:
343 case TCP_STATE_FIN_WAIT_1:
344 case TCP_STATE_FIN_WAIT_2:
345 case TCP_STATE_CLOSING:
346 case TCP_STATE_LAST_ACK:
347 tcp_connection_timers_reset (tc);
348 tcp_timer_set (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
349 tcp_cong_recovery_off (tc);
350 tcp_program_reset_ntf (wrk, tc);
351 /* Make sure we mark the session as closed. In some states we may
352 * be still trying to send data */
353 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
355 case TCP_STATE_CLOSED:
356 case TCP_STATE_TIME_WAIT:
359 TCP_DBG ("reset state: %u", tc->state);
364 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
366 * It first verifies if segment has a wrapped sequence number (PAWS) and then
367 * does the processing associated to the first four steps (ignoring security
368 * and precedence): sequence number, rst bit and syn bit checks.
370 * @return 0 if segments passes validation.
373 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
374 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
376 /* We could get a burst of RSTs interleaved with acks */
377 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
379 tcp_send_reset (tc0);
380 *error0 = TCP_ERROR_CONNECTION_CLOSED;
384 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
386 *error0 = TCP_ERROR_SEGMENT_INVALID;
390 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
392 *error0 = TCP_ERROR_OPTIONS;
396 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
398 *error0 = TCP_ERROR_PAWS;
399 TCP_EVT (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
400 vnet_buffer (b0)->tcp.seq_end);
402 /* If it just so happens that a segment updates tsval_recent for a
403 * segment over 24 days old, invalidate tsval_recent. */
404 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
405 tcp_time_now_w_thread (tc0->c_thread_index)))
407 tc0->tsval_recent = tc0->rcv_opts.tsval;
408 clib_warning ("paws failed: 24-day old segment");
410 /* Drop after ack if not rst. Resets can fail paws check as per
411 * RFC 7323 sec. 5.2: When an <RST> segment is received, it MUST NOT
412 * be subjected to the PAWS check by verifying an acceptable value in
414 else if (!tcp_rst (th0))
416 tcp_program_ack (tc0);
417 TCP_EVT (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
422 /* 1st: check sequence number */
423 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
424 vnet_buffer (b0)->tcp.seq_end))
426 /* SYN/SYN-ACK retransmit */
428 && vnet_buffer (b0)->tcp.seq_number == tc0->rcv_nxt - 1)
430 tcp_options_parse (th0, &tc0->rcv_opts, 1);
431 if (tc0->state == TCP_STATE_SYN_RCVD)
433 tcp_send_synack (tc0);
434 TCP_EVT (TCP_EVT_SYN_RCVD, tc0, 0);
435 *error0 = TCP_ERROR_SYNS_RCVD;
439 tcp_program_ack (tc0);
440 TCP_EVT (TCP_EVT_SYNACK_RCVD, tc0);
441 *error0 = TCP_ERROR_SYN_ACKS_RCVD;
446 /* If our window is 0 and the packet is in sequence, let it pass
447 * through for ack processing. It should be dropped later. */
448 if (tc0->rcv_wnd < tc0->snd_mss
449 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
452 /* If we entered recovery and peer did so as well, there's a chance that
453 * dup acks won't be acceptable on either end because seq_end may be less
454 * than rcv_las. This can happen if acks are lost in both directions. */
455 if (tcp_in_recovery (tc0)
456 && seq_geq (vnet_buffer (b0)->tcp.seq_number,
457 tc0->rcv_las - tc0->rcv_wnd)
458 && seq_leq (vnet_buffer (b0)->tcp.seq_end,
459 tc0->rcv_nxt + tc0->rcv_wnd))
462 *error0 = TCP_ERROR_RCV_WND;
464 /* If we advertised a zero rcv_wnd and the segment is in the past or the
465 * next one that we expect, it is probably a window probe */
466 if ((tc0->flags & TCP_CONN_ZERO_RWND_SENT)
467 && seq_lt (vnet_buffer (b0)->tcp.seq_end,
468 tc0->rcv_las + tc0->rcv_opts.mss))
469 *error0 = TCP_ERROR_ZERO_RWND;
471 tc0->errors.below_data_wnd += seq_lt (vnet_buffer (b0)->tcp.seq_end,
474 /* If not RST, send dup ack */
477 tcp_program_dupack (tc0);
478 TCP_EVT (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
486 /* 2nd: check the RST bit */
487 if (PREDICT_FALSE (tcp_rst (th0)))
489 tcp_rcv_rst (wrk, tc0);
490 *error0 = TCP_ERROR_RST_RCVD;
494 /* 3rd: check security and precedence (skip) */
496 /* 4th: check the SYN bit (in window) */
497 if (PREDICT_FALSE (tcp_syn (th0)))
499 /* As per RFC5961 send challenge ack instead of reset */
500 tcp_program_ack (tc0);
501 *error0 = TCP_ERROR_SPURIOUS_SYN;
505 /* If segment in window, save timestamp */
506 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
507 vnet_buffer (b0)->tcp.seq_end);
515 tcp_rcv_ack_no_cc (tcp_connection_t * tc, vlib_buffer_t * b, u32 * error)
517 /* SND.UNA =< SEG.ACK =< SND.NXT */
518 if (!(seq_leq (tc->snd_una, vnet_buffer (b)->tcp.ack_number)
519 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
521 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
522 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
524 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
527 *error = TCP_ERROR_ACK_INVALID;
532 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
533 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
534 *error = TCP_ERROR_ACK_OK;
539 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
541 * Note that although the original article, srtt and rttvar are scaled
542 * to minimize round-off errors, here we don't. Instead, we rely on
543 * better precision time measurements.
545 * TODO support us rtt resolution
548 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
554 err = mrtt - tc->srtt;
556 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
557 * The increase should be bound */
558 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
559 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
560 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
564 /* First measurement. */
566 tc->rttvar = mrtt >> 1;
570 #ifndef CLIB_MARCH_VARIANT
572 tcp_update_rto (tcp_connection_t * tc)
574 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
575 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
577 #endif /* CLIB_MARCH_VARIANT */
580 * Update RTT estimate and RTO timer
582 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
583 * timing. Middle boxes are known to fiddle with TCP options so we
584 * should give higher priority to ACK timing.
586 * This should be called only if previously sent bytes have been acked.
588 * return 1 if valid rtt 0 otherwise
591 tcp_update_rtt (tcp_connection_t * tc, tcp_rate_sample_t * rs, u32 ack)
595 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
596 * RTT because they're ambiguous. */
597 if (tcp_in_cong_recovery (tc))
599 /* Accept rtt estimates for samples that have not been retransmitted */
600 if ((tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
601 && !(rs->flags & TCP_BTS_IS_RXT))
603 mrtt = rs->rtt_time * THZ;
609 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
611 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
612 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
613 mrtt = clib_max ((u32) (sample * THZ), 1);
614 /* Allow measuring of a new RTT */
617 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
618 * snd_una, i.e., the left side of the send window:
619 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
620 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
622 u32 now = tcp_tstamp (tc);
623 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
628 /* Ignore dubious measurements */
629 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
632 tcp_estimate_rtt (tc, mrtt);
636 /* If we got here something must've been ACKed so make sure boff is 0,
637 * even if mrtt is not valid since we update the rto lower */
645 tcp_estimate_initial_rtt (tcp_connection_t * tc)
647 u8 thread_index = vlib_num_workers ()? 1 : 0;
652 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
653 tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001);
654 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
659 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
660 mrtt = clib_max (mrtt, 1);
661 /* Due to retransmits we don't know the initial mrtt */
662 if (tc->rto_boff && mrtt > 1 * THZ)
664 tc->mrtt_us = (f64) mrtt *TCP_TICK;
667 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
668 tcp_estimate_rtt (tc, mrtt);
673 * Dequeue bytes for connections that have received acks in last burst
676 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
678 u32 thread_index = wrk->vm->thread_index;
679 u32 *pending_deq_acked;
680 tcp_connection_t *tc;
683 if (!vec_len (wrk->pending_deq_acked))
686 pending_deq_acked = wrk->pending_deq_acked;
687 for (i = 0; i < vec_len (pending_deq_acked); i++)
689 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
690 tc->flags &= ~TCP_CONN_DEQ_PENDING;
692 if (PREDICT_FALSE (!tc->burst_acked))
695 /* Dequeue the newly ACKed bytes */
696 session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
697 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
699 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
701 if (seq_leq (tc->psh_seq, tc->snd_una))
702 tc->flags &= ~TCP_CONN_PSH_PENDING;
705 /* If everything has been acked, stop retransmit timer
706 * otherwise update. */
707 tcp_retransmit_timer_update (tc);
709 /* Update pacer based on our new cwnd estimate */
710 tcp_connection_tx_pacer_update (tc);
714 _vec_len (wrk->pending_deq_acked) = 0;
718 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
720 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
722 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
723 tc->flags |= TCP_CONN_DEQ_PENDING;
725 tc->burst_acked += tc->bytes_acked;
728 #ifndef CLIB_MARCH_VARIANT
730 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
732 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
733 return hole - sb->holes;
737 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
739 return hole->end - hole->start;
742 sack_scoreboard_hole_t *
743 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
745 if (index != TCP_INVALID_SACK_HOLE_INDEX)
746 return pool_elt_at_index (sb->holes, index);
750 sack_scoreboard_hole_t *
751 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
753 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
754 return pool_elt_at_index (sb->holes, hole->next);
758 sack_scoreboard_hole_t *
759 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
761 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
762 return pool_elt_at_index (sb->holes, hole->prev);
766 sack_scoreboard_hole_t *
767 scoreboard_first_hole (sack_scoreboard_t * sb)
769 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
770 return pool_elt_at_index (sb->holes, sb->head);
774 sack_scoreboard_hole_t *
775 scoreboard_last_hole (sack_scoreboard_t * sb)
777 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
778 return pool_elt_at_index (sb->holes, sb->tail);
783 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
785 sack_scoreboard_hole_t *next, *prev;
787 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
789 next = pool_elt_at_index (sb->holes, hole->next);
790 next->prev = hole->prev;
794 sb->tail = hole->prev;
797 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
799 prev = pool_elt_at_index (sb->holes, hole->prev);
800 prev->next = hole->next;
804 sb->head = hole->next;
807 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
808 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
810 /* Poison the entry */
812 clib_memset (hole, 0xfe, sizeof (*hole));
814 pool_put (sb->holes, hole);
817 static sack_scoreboard_hole_t *
818 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
821 sack_scoreboard_hole_t *hole, *next, *prev;
824 pool_get (sb->holes, hole);
825 clib_memset (hole, 0, sizeof (*hole));
829 hole_index = scoreboard_hole_index (sb, hole);
831 prev = scoreboard_get_hole (sb, prev_index);
834 hole->prev = prev_index;
835 hole->next = prev->next;
837 if ((next = scoreboard_next_hole (sb, hole)))
838 next->prev = hole_index;
840 sb->tail = hole_index;
842 prev->next = hole_index;
846 sb->head = hole_index;
847 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
848 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
855 scoreboard_update_sacked_rxt (sack_scoreboard_t * sb, u32 start, u32 end,
858 if (!has_rxt || seq_geq (start, sb->high_rxt))
862 seq_lt (end, sb->high_rxt) ? (end - start) : (sb->high_rxt - start);
866 scoreboard_update_bytes (sack_scoreboard_t * sb, u32 ack, u32 snd_mss)
868 sack_scoreboard_hole_t *left, *right;
869 u32 sacked = 0, blks = 0, old_sacked;
871 old_sacked = sb->sacked_bytes;
873 sb->last_lost_bytes = 0;
875 sb->sacked_bytes = 0;
877 right = scoreboard_last_hole (sb);
880 sb->sacked_bytes = sb->high_sacked - ack;
881 sb->last_sacked_bytes = sb->sacked_bytes
882 - (old_sacked - sb->last_bytes_delivered);
886 if (seq_gt (sb->high_sacked, right->end))
888 sacked = sb->high_sacked - right->end;
892 while (sacked < (TCP_DUPACK_THRESHOLD - 1) * snd_mss
893 && blks < TCP_DUPACK_THRESHOLD)
896 sb->lost_bytes += scoreboard_hole_bytes (right);
898 left = scoreboard_prev_hole (sb, right);
901 ASSERT (right->start == ack || sb->is_reneging);
902 sacked += right->start - ack;
907 sacked += right->start - left->end;
912 /* right is first lost */
915 sb->lost_bytes += scoreboard_hole_bytes (right);
916 sb->last_lost_bytes += right->is_lost ? 0 : (right->end - right->start);
918 left = scoreboard_prev_hole (sb, right);
921 ASSERT (right->start == ack || sb->is_reneging);
922 sacked += right->start - ack;
925 sacked += right->start - left->end;
929 sb->sacked_bytes = sacked;
930 sb->last_sacked_bytes = sacked - (old_sacked - sb->last_bytes_delivered);
934 * Figure out the next hole to retransmit
936 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
938 sack_scoreboard_hole_t *
939 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
940 sack_scoreboard_hole_t * start,
941 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
943 sack_scoreboard_hole_t *hole = 0;
945 hole = start ? start : scoreboard_first_hole (sb);
946 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
947 hole = scoreboard_next_hole (sb, hole);
949 /* Nothing, return */
952 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
956 /* Rule (1): if higher than rxt, less than high_sacked and lost */
957 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
959 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
963 /* Rule (2): available unsent data */
966 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
969 /* Rule (3): if hole not lost */
970 else if (seq_lt (hole->start, sb->high_sacked))
972 /* And we didn't already retransmit it */
973 if (seq_leq (hole->end, sb->high_rxt))
975 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
979 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
981 /* Rule (4): if hole beyond high_sacked */
984 ASSERT (seq_geq (hole->start, sb->high_sacked));
987 /* HighRxt MUST NOT be updated */
992 if (hole && seq_lt (sb->high_rxt, hole->start))
993 sb->high_rxt = hole->start;
999 scoreboard_init_rxt (sack_scoreboard_t * sb, u32 snd_una)
1001 sack_scoreboard_hole_t *hole;
1002 hole = scoreboard_first_hole (sb);
1005 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
1006 sb->cur_rxt_hole = sb->head;
1008 sb->high_rxt = snd_una;
1009 sb->rescue_rxt = snd_una - 1;
1013 scoreboard_init (sack_scoreboard_t * sb)
1015 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
1016 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
1017 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
1021 scoreboard_clear (sack_scoreboard_t * sb)
1023 sack_scoreboard_hole_t *hole;
1024 while ((hole = scoreboard_first_hole (sb)))
1026 scoreboard_remove_hole (sb, hole);
1028 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
1029 ASSERT (pool_elts (sb->holes) == 0);
1030 sb->sacked_bytes = 0;
1031 sb->last_sacked_bytes = 0;
1032 sb->last_bytes_delivered = 0;
1034 sb->last_lost_bytes = 0;
1035 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
1036 sb->is_reneging = 0;
1040 scoreboard_clear_reneging (sack_scoreboard_t * sb, u32 start, u32 end)
1042 sack_scoreboard_hole_t *last_hole;
1044 clib_warning ("sack reneging");
1046 scoreboard_clear (sb);
1047 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1049 last_hole->is_lost = 1;
1050 sb->tail = scoreboard_hole_index (sb, last_hole);
1051 sb->high_sacked = start;
1052 scoreboard_init_rxt (sb, start);
1055 #endif /* CLIB_MARCH_VARIANT */
1058 * Test that scoreboard is sane after recovery
1060 * Returns 1 if scoreboard is empty or if first hole beyond
1064 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
1066 sack_scoreboard_hole_t *hole;
1067 hole = scoreboard_first_hole (&tc->sack_sb);
1068 return (!hole || (seq_geq (hole->start, tc->snd_una)
1069 && seq_lt (hole->end, tc->snd_nxt)));
1072 #ifndef CLIB_MARCH_VARIANT
1075 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
1077 sack_scoreboard_hole_t *hole, *next_hole;
1078 sack_scoreboard_t *sb = &tc->sack_sb;
1079 sack_block_t *blk, *rcv_sacks;
1080 u32 blk_index = 0, i, j;
1083 sb->last_sacked_bytes = 0;
1084 sb->last_bytes_delivered = 0;
1087 if (!tcp_opts_sack (&tc->rcv_opts) && !sb->sacked_bytes
1088 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1091 has_rxt = tcp_in_cong_recovery (tc);
1093 /* Remove invalid blocks */
1094 blk = tc->rcv_opts.sacks;
1095 while (blk < vec_end (tc->rcv_opts.sacks))
1097 if (seq_lt (blk->start, blk->end)
1098 && seq_gt (blk->start, tc->snd_una)
1099 && seq_gt (blk->start, ack)
1100 && seq_lt (blk->start, tc->snd_nxt)
1101 && seq_leq (blk->end, tc->snd_nxt))
1106 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
1109 /* Add block for cumulative ack */
1110 if (seq_gt (ack, tc->snd_una))
1112 vec_add2 (tc->rcv_opts.sacks, blk, 1);
1113 blk->start = tc->snd_una;
1117 if (vec_len (tc->rcv_opts.sacks) == 0)
1120 tcp_scoreboard_trace_add (tc, ack);
1122 /* Make sure blocks are ordered */
1123 rcv_sacks = tc->rcv_opts.sacks;
1124 for (i = 0; i < vec_len (rcv_sacks); i++)
1125 for (j = i + 1; j < vec_len (rcv_sacks); j++)
1126 if (seq_lt (rcv_sacks[j].start, rcv_sacks[i].start))
1128 sack_block_t tmp = rcv_sacks[i];
1129 rcv_sacks[i] = rcv_sacks[j];
1133 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1135 /* Handle reneging as a special case */
1136 if (PREDICT_FALSE (sb->is_reneging))
1138 /* No holes, only sacked bytes */
1139 if (seq_leq (tc->snd_nxt, sb->high_sacked))
1141 /* No progress made so return */
1142 if (seq_leq (ack, tc->snd_una))
1145 /* Update sacked bytes delivered and return */
1146 sb->last_bytes_delivered = ack - tc->snd_una;
1147 sb->sacked_bytes -= sb->last_bytes_delivered;
1148 sb->is_reneging = seq_lt (ack, sb->high_sacked);
1152 /* New hole above high sacked. Add it and process normally */
1153 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1154 sb->high_sacked, tc->snd_nxt);
1155 sb->tail = scoreboard_hole_index (sb, hole);
1157 /* Not reneging and no holes. Insert the first that covers all
1158 * outstanding bytes */
1161 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1162 tc->snd_una, tc->snd_nxt);
1163 sb->tail = scoreboard_hole_index (sb, hole);
1165 sb->high_sacked = rcv_sacks[vec_len (rcv_sacks) - 1].end;
1169 /* If we have holes but snd_nxt is beyond the last hole, update
1170 * last hole end or add new hole after high sacked */
1171 hole = scoreboard_last_hole (sb);
1172 if (seq_gt (tc->snd_nxt, hole->end))
1174 if (seq_geq (hole->start, sb->high_sacked))
1176 hole->end = tc->snd_nxt;
1178 /* New hole after high sacked block */
1179 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1181 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1186 /* Keep track of max byte sacked for when the last hole
1188 sb->high_sacked = seq_max (rcv_sacks[vec_len (rcv_sacks) - 1].end,
1192 /* Walk the holes with the SACK blocks */
1193 hole = pool_elt_at_index (sb->holes, sb->head);
1195 if (PREDICT_FALSE (sb->is_reneging))
1197 sb->last_bytes_delivered += clib_min (hole->start - tc->snd_una,
1199 sb->is_reneging = seq_lt (ack, hole->start);
1202 while (hole && blk_index < vec_len (rcv_sacks))
1204 blk = &rcv_sacks[blk_index];
1205 if (seq_leq (blk->start, hole->start))
1207 /* Block covers hole. Remove hole */
1208 if (seq_geq (blk->end, hole->end))
1210 next_hole = scoreboard_next_hole (sb, hole);
1212 /* If covered by ack, compute delivered bytes */
1213 if (blk->end == ack)
1215 u32 sacked = next_hole ? next_hole->start : sb->high_sacked;
1216 if (PREDICT_FALSE (seq_lt (ack, sacked)))
1218 sb->last_bytes_delivered += ack - hole->end;
1219 sb->is_reneging = 1;
1223 sb->last_bytes_delivered += sacked - hole->end;
1224 sb->is_reneging = 0;
1227 scoreboard_update_sacked_rxt (sb, hole->start, hole->end,
1229 scoreboard_remove_hole (sb, hole);
1232 /* Partial 'head' overlap */
1235 if (seq_gt (blk->end, hole->start))
1237 scoreboard_update_sacked_rxt (sb, hole->start, blk->end,
1239 hole->start = blk->end;
1246 /* Hole must be split */
1247 if (seq_lt (blk->end, hole->end))
1249 u32 hole_index = scoreboard_hole_index (sb, hole);
1250 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1252 /* Pool might've moved */
1253 hole = scoreboard_get_hole (sb, hole_index);
1254 hole->end = blk->start;
1256 scoreboard_update_sacked_rxt (sb, blk->start, blk->end,
1260 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1262 else if (seq_lt (blk->start, hole->end))
1264 scoreboard_update_sacked_rxt (sb, blk->start, hole->end,
1266 hole->end = blk->start;
1268 hole = scoreboard_next_hole (sb, hole);
1272 scoreboard_update_bytes (sb, ack, tc->snd_mss);
1274 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1275 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1276 || sb->sacked_bytes <= tc->snd_nxt - seq_max (tc->snd_una, ack));
1277 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1278 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1279 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1280 || sb->is_reneging || sb->holes[sb->head].start == ack);
1281 ASSERT (sb->last_lost_bytes <= sb->lost_bytes);
1282 ASSERT ((ack - tc->snd_una) + sb->last_sacked_bytes
1283 - sb->last_bytes_delivered >= sb->rxt_sacked);
1284 ASSERT ((ack - tc->snd_una) >= tc->sack_sb.last_bytes_delivered
1285 || (tc->flags & TCP_CONN_FINSNT));
1287 TCP_EVT (TCP_EVT_CC_SCOREBOARD, tc);
1289 #endif /* CLIB_MARCH_VARIANT */
1292 * Try to update snd_wnd based on feedback received from peer.
1294 * If successful, and new window is 'effectively' 0, activate persist
1298 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1300 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1301 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1302 if (seq_lt (tc->snd_wl1, seq)
1303 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1305 tc->snd_wnd = snd_wnd;
1308 TCP_EVT (TCP_EVT_SND_WND, tc);
1310 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1312 /* Set persist timer if not set and we just got 0 wnd */
1313 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1314 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1315 tcp_persist_timer_set (tc);
1319 tcp_persist_timer_reset (tc);
1320 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1323 tcp_update_rto (tc);
1330 * Init loss recovery/fast recovery.
1332 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1333 * updated in @ref tcp_cc_handle_event after fast retransmit
1336 tcp_cc_init_congestion (tcp_connection_t * tc)
1338 tcp_fastrecovery_on (tc);
1339 tc->snd_congestion = tc->snd_nxt;
1340 tc->cwnd_acc_bytes = 0;
1341 tc->snd_rxt_bytes = 0;
1342 tc->rxt_delivered = 0;
1343 tc->prr_delivered = 0;
1344 tc->prr_start = tc->snd_una;
1345 tc->prev_ssthresh = tc->ssthresh;
1346 tc->prev_cwnd = tc->cwnd;
1348 tc->snd_rxt_ts = tcp_tstamp (tc);
1349 tcp_cc_congestion (tc);
1351 /* Post retransmit update cwnd to ssthresh and account for the
1352 * three segments that have left the network and should've been
1353 * buffered at the receiver XXX */
1354 if (!tcp_opts_sack_permitted (&tc->rcv_opts))
1355 tc->cwnd += 3 * tc->snd_mss;
1357 tc->fr_occurences += 1;
1358 TCP_EVT (TCP_EVT_CC_EVT, tc, 4);
1362 tcp_cc_congestion_undo (tcp_connection_t * tc)
1364 tc->cwnd = tc->prev_cwnd;
1365 tc->ssthresh = tc->prev_ssthresh;
1366 tcp_cc_undo_recovery (tc);
1367 ASSERT (tc->rto_boff == 0);
1368 TCP_EVT (TCP_EVT_CC_EVT, tc, 5);
1372 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1374 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1376 && tcp_opts_tstamp (&tc->rcv_opts)
1377 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1381 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1383 return (tcp_cc_is_spurious_timeout_rxt (tc));
1387 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1389 return (tc->sack_sb.lost_bytes
1390 || ((TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
1391 < tc->sack_sb.sacked_bytes));
1395 tcp_should_fastrecover (tcp_connection_t * tc, u8 has_sack)
1399 /* If of of the two conditions lower hold, reset dupacks because
1400 * we're probably after timeout (RFC6582 heuristics).
1401 * If Cumulative ack does not cover more than congestion threshold,
1403 * 1) The following doesn't hold: The congestion window is greater
1404 * than SMSS bytes and the difference between highest_ack
1405 * and prev_highest_ack is at most 4*SMSS bytes
1406 * 2) Echoed timestamp in the last non-dup ack does not equal the
1409 if (seq_leq (tc->snd_una, tc->snd_congestion)
1410 && ((!(tc->cwnd > tc->snd_mss
1411 && tc->bytes_acked <= 4 * tc->snd_mss))
1412 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1414 tc->rcv_dupacks = 0;
1418 return ((tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1419 || tcp_should_fastrecover_sack (tc));
1423 tcp_cc_recover (tcp_connection_t * tc)
1425 sack_scoreboard_hole_t *hole;
1428 ASSERT (tcp_in_cong_recovery (tc));
1430 if (tcp_cc_is_spurious_retransmit (tc))
1432 tcp_cc_congestion_undo (tc);
1436 tcp_connection_tx_pacer_reset (tc, tc->cwnd, 0 /* start bucket */ );
1437 tc->rcv_dupacks = 0;
1439 /* Previous recovery left us congested. Continue sending as part
1440 * of the current recovery event with an updated snd_congestion */
1441 if (tc->sack_sb.sacked_bytes)
1443 tc->snd_congestion = tc->snd_nxt;
1444 tcp_program_retransmit (tc);
1448 tc->rxt_delivered = 0;
1449 tc->snd_rxt_bytes = 0;
1451 tc->prr_delivered = 0;
1453 tc->flags &= ~TCP_CONN_RXT_PENDING;
1455 hole = scoreboard_first_hole (&tc->sack_sb);
1456 if (hole && hole->start == tc->snd_una && hole->end == tc->snd_nxt)
1457 scoreboard_clear (&tc->sack_sb);
1459 if (!tcp_in_recovery (tc) && !is_spurious)
1460 tcp_cc_recovered (tc);
1462 tcp_fastrecovery_off (tc);
1463 tcp_fastrecovery_first_off (tc);
1464 tcp_recovery_off (tc);
1465 TCP_EVT (TCP_EVT_CC_EVT, tc, 3);
1467 ASSERT (tc->rto_boff == 0);
1468 ASSERT (!tcp_in_cong_recovery (tc));
1469 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1474 tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1476 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1478 /* Congestion avoidance */
1479 tcp_cc_rcv_ack (tc, rs);
1481 /* If a cumulative ack, make sure dupacks is 0 */
1482 tc->rcv_dupacks = 0;
1484 /* When dupacks hits the threshold we only enter fast retransmit if
1485 * cumulative ack covers more than snd_congestion. Should snd_una
1486 * wrap this test may fail under otherwise valid circumstances.
1487 * Therefore, proactively update snd_congestion when wrap detected. */
1489 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1490 && seq_gt (tc->snd_congestion, tc->snd_una)))
1491 tc->snd_congestion = tc->snd_una - 1;
1495 * One function to rule them all ... and in the darkness bind them
1498 tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs,
1501 u8 has_sack = tcp_opts_sack_permitted (&tc->rcv_opts);
1503 /* If reneging, wait for timer based retransmits */
1504 if (PREDICT_FALSE (tcp_is_lost_fin (tc) || tc->sack_sb.is_reneging))
1508 * If not in recovery, figure out if we should enter
1510 if (!tcp_in_cong_recovery (tc))
1515 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1516 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1518 if (tcp_should_fastrecover (tc, has_sack))
1520 tcp_cc_init_congestion (tc);
1523 scoreboard_init_rxt (&tc->sack_sb, tc->snd_una);
1525 tcp_connection_tx_pacer_reset (tc, tc->cwnd, 0 /* start bucket */ );
1526 tcp_program_retransmit (tc);
1533 * Already in recovery
1537 * Process (re)transmit feedback. Output path uses this to decide how much
1538 * more data to release into the network
1542 if (!tc->bytes_acked && tc->sack_sb.rxt_sacked)
1543 tcp_fastrecovery_first_on (tc);
1545 tc->rxt_delivered += tc->sack_sb.rxt_sacked;
1546 tc->prr_delivered += tc->bytes_acked + tc->sack_sb.last_sacked_bytes
1547 - tc->sack_sb.last_bytes_delivered;
1549 tcp_program_retransmit (tc);
1555 tc->rcv_dupacks += 1;
1556 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1558 tc->rxt_delivered = clib_min (tc->rxt_delivered + tc->bytes_acked,
1561 tc->prr_delivered += clib_min (tc->snd_mss,
1562 tc->snd_nxt - tc->snd_una);
1564 tc->prr_delivered += tc->bytes_acked - clib_min (tc->bytes_acked,
1568 /* If partial ack, assume that the first un-acked segment was lost */
1569 if (tc->bytes_acked || tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1570 tcp_fastrecovery_first_on (tc);
1572 tcp_program_retransmit (tc);
1576 * See if we can exit and stop retransmitting
1578 if (seq_geq (tc->snd_una, tc->snd_congestion))
1580 /* If spurious return, we've already updated everything */
1581 if (tcp_cc_recover (tc))
1583 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1587 /* Treat as congestion avoidance ack */
1588 tcp_cc_rcv_ack (tc, rs);
1593 * Notify cc of the event
1596 if (!tc->bytes_acked)
1598 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1602 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1603 * reset dupacks to 0. Also needed if in congestion recovery */
1604 tc->rcv_dupacks = 0;
1606 if (tcp_in_recovery (tc))
1607 tcp_cc_rcv_ack (tc, rs);
1609 tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs);
1613 tcp_handle_old_ack (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1615 if (!tcp_in_cong_recovery (tc))
1618 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1619 tcp_rcv_sacks (tc, tc->snd_una);
1621 tc->bytes_acked = 0;
1623 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
1624 tcp_bt_sample_delivery_rate (tc, rs);
1626 tcp_cc_handle_event (tc, rs, 1);
1630 * Check if duplicate ack as per RFC5681 Sec. 2
1633 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
1636 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
1637 && seq_gt (tc->snd_nxt, tc->snd_una)
1638 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
1639 && (prev_snd_wnd == tc->snd_wnd));
1643 * Checks if ack is a congestion control event.
1646 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
1647 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
1649 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
1650 * defined to be 'duplicate' as well */
1651 *is_dack = tc->sack_sb.last_sacked_bytes
1652 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
1654 return (*is_dack || tcp_in_cong_recovery (tc));
1658 * Process incoming ACK
1661 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1662 tcp_header_t * th, u32 * error)
1664 u32 prev_snd_wnd, prev_snd_una;
1665 tcp_rate_sample_t rs = { 0 };
1668 TCP_EVT (TCP_EVT_CC_STAT, tc);
1670 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1671 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1673 /* We've probably entered recovery and the peer still has some
1674 * of the data we've sent. Update snd_nxt and accept the ack */
1675 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1676 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1678 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1682 tc->errors.above_ack_wnd += 1;
1683 *error = TCP_ERROR_ACK_FUTURE;
1684 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 0, vnet_buffer (b)->tcp.ack_number);
1688 /* If old ACK, probably it's an old dupack */
1689 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1691 tc->errors.below_ack_wnd += 1;
1692 *error = TCP_ERROR_ACK_OLD;
1693 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 1, vnet_buffer (b)->tcp.ack_number);
1695 if (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una - tc->rcv_wnd))
1698 tcp_handle_old_ack (tc, &rs);
1700 /* Don't drop yet */
1707 * Looks okay, process feedback
1710 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1711 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1713 prev_snd_wnd = tc->snd_wnd;
1714 prev_snd_una = tc->snd_una;
1715 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1716 vnet_buffer (b)->tcp.ack_number,
1717 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1718 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1719 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
1720 tcp_validate_txf_size (tc, tc->bytes_acked);
1722 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
1723 tcp_bt_sample_delivery_rate (tc, &rs);
1725 if (tc->bytes_acked)
1727 tcp_program_dequeue (wrk, tc);
1728 tcp_update_rtt (tc, &rs, vnet_buffer (b)->tcp.ack_number);
1731 TCP_EVT (TCP_EVT_ACK_RCVD, tc);
1734 * Check if we have congestion event
1737 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1739 tcp_cc_handle_event (tc, &rs, is_dack);
1740 tc->dupacks_in += is_dack;
1741 if (!tcp_in_cong_recovery (tc))
1743 *error = TCP_ERROR_ACK_OK;
1746 *error = TCP_ERROR_ACK_DUP;
1747 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1753 * Update congestion control (slow start/congestion avoidance)
1755 tcp_cc_update (tc, &rs);
1756 *error = TCP_ERROR_ACK_OK;
1761 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1763 if (!tcp_disconnect_pending (tc))
1765 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1766 tcp_disconnect_pending_on (tc);
1771 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1773 u32 thread_index, *pending_disconnects, *pending_resets;
1774 tcp_connection_t *tc;
1777 if (vec_len (wrk->pending_disconnects))
1779 thread_index = wrk->vm->thread_index;
1780 pending_disconnects = wrk->pending_disconnects;
1781 for (i = 0; i < vec_len (pending_disconnects); i++)
1783 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1784 tcp_disconnect_pending_off (tc);
1785 session_transport_closing_notify (&tc->connection);
1787 _vec_len (wrk->pending_disconnects) = 0;
1790 if (vec_len (wrk->pending_resets))
1792 thread_index = wrk->vm->thread_index;
1793 pending_resets = wrk->pending_resets;
1794 for (i = 0; i < vec_len (pending_resets); i++)
1796 tc = tcp_connection_get (pending_resets[i], thread_index);
1797 tcp_disconnect_pending_off (tc);
1798 tcp_handle_rst (tc);
1800 _vec_len (wrk->pending_resets) = 0;
1805 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1808 /* Reject out-of-order fins */
1809 if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt)
1812 /* Account for the FIN and send ack */
1814 tc->flags |= TCP_CONN_FINRCVD;
1815 tcp_program_ack (tc);
1816 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1817 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1818 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1819 tcp_program_disconnect (wrk, tc);
1820 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
1821 TCP_EVT (TCP_EVT_FIN_RCVD, tc);
1822 *error = TCP_ERROR_FIN_RCVD;
1825 #ifndef CLIB_MARCH_VARIANT
1827 tcp_sack_vector_is_sane (sack_block_t * sacks)
1830 for (i = 1; i < vec_len (sacks); i++)
1832 if (sacks[i - 1].end == sacks[i].start)
1839 * Build SACK list as per RFC2018.
1841 * Makes sure the first block contains the segment that generated the current
1842 * ACK and the following ones are the ones most recently reported in SACK
1845 * @param tc TCP connection for which the SACK list is updated
1846 * @param start Start sequence number of the newest SACK block
1847 * @param end End sequence of the newest SACK block
1850 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1852 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1855 /* If the first segment is ooo add it to the list. Last write might've moved
1856 * rcv_nxt over the first segment. */
1857 if (seq_lt (tc->rcv_nxt, start))
1859 vec_add2 (new_list, block, 1);
1860 block->start = start;
1864 /* Find the blocks still worth keeping. */
1865 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1867 /* Discard if rcv_nxt advanced beyond current block */
1868 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1871 /* Merge or drop if segment overlapped by the new segment */
1872 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1873 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1875 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1876 new_list[0].start = tc->snd_sacks[i].start;
1877 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1878 new_list[0].end = tc->snd_sacks[i].end;
1882 /* Save to new SACK list if we have space. */
1883 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1884 vec_add1 (new_list, tc->snd_sacks[i]);
1887 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1889 /* Replace old vector with new one */
1890 vec_reset_length (tc->snd_sacks);
1891 tc->snd_sacks_fl = tc->snd_sacks;
1892 tc->snd_sacks = new_list;
1894 /* Segments should not 'touch' */
1895 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1899 tcp_sack_list_bytes (tcp_connection_t * tc)
1902 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1903 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1906 #endif /* CLIB_MARCH_VARIANT */
1908 /** Enqueue data for delivery to application */
1910 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1913 int written, error = TCP_ERROR_ENQUEUED;
1915 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1917 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1918 1 /* queue event */ , 1);
1919 tc->bytes_in += written;
1921 TCP_EVT (TCP_EVT_INPUT, tc, 0, data_len, written);
1923 /* Update rcv_nxt */
1924 if (PREDICT_TRUE (written == data_len))
1926 tc->rcv_nxt += written;
1928 /* If more data written than expected, account for out-of-order bytes. */
1929 else if (written > data_len)
1931 tc->rcv_nxt += written;
1932 TCP_EVT (TCP_EVT_CC_INPUT, tc, data_len, written);
1934 else if (written > 0)
1936 /* We've written something but FIFO is probably full now */
1937 tc->rcv_nxt += written;
1938 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1942 return TCP_ERROR_FIFO_FULL;
1945 /* Update SACK list if need be */
1946 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1948 /* Remove SACK blocks that have been delivered */
1949 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1955 /** Enqueue out-of-order data */
1957 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1963 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1966 /* Enqueue out-of-order data with relative offset */
1967 rv = session_enqueue_stream_connection (&tc->connection, b,
1968 vnet_buffer (b)->tcp.seq_number -
1969 tc->rcv_nxt, 0 /* queue event */ ,
1972 /* Nothing written */
1975 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, 0);
1976 return TCP_ERROR_FIFO_FULL;
1979 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1980 tc->bytes_in += data_len;
1982 /* Update SACK list if in use */
1983 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1985 ooo_segment_t *newest;
1988 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1990 /* Get the newest segment from the fifo */
1991 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1994 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1995 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1996 start = tc->rcv_nxt + offset;
1997 end = start + ooo_segment_length (s0->rx_fifo, newest);
1998 tcp_update_sack_list (tc, start, end);
1999 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
2000 TCP_EVT (TCP_EVT_CC_SACKS, tc);
2004 return TCP_ERROR_ENQUEUED_OOO;
2008 * Check if ACK could be delayed. If ack can be delayed, it should return
2009 * true for a full frame. If we're always acking return 0.
2012 tcp_can_delack (tcp_connection_t * tc)
2014 /* Send ack if ... */
2016 /* just sent a rcv wnd 0
2017 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
2018 /* constrained to send ack */
2019 || (tc->flags & TCP_CONN_SNDACK) != 0
2020 /* we're almost out of tx wnd */
2021 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
2028 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
2030 u32 discard, first = b->current_length;
2031 vlib_main_t *vm = vlib_get_main ();
2033 /* Handle multi-buffer segments */
2034 if (n_bytes_to_drop > b->current_length)
2036 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
2040 discard = clib_min (n_bytes_to_drop, b->current_length);
2041 vlib_buffer_advance (b, discard);
2042 b = vlib_get_buffer (vm, b->next_buffer);
2043 n_bytes_to_drop -= discard;
2045 while (n_bytes_to_drop);
2046 if (n_bytes_to_drop > first)
2047 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
2050 vlib_buffer_advance (b, n_bytes_to_drop);
2051 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
2056 * Receive buffer for connection and handle acks
2058 * It handles both in order or out-of-order data.
2061 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
2064 u32 error, n_bytes_to_drop, n_data_bytes;
2066 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
2067 n_data_bytes = vnet_buffer (b)->tcp.data_len;
2068 ASSERT (n_data_bytes);
2069 tc->data_segs_in += 1;
2071 /* Handle out-of-order data */
2072 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
2074 /* Old sequence numbers allowed through because they overlapped
2076 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
2078 /* Completely in the past (possible retransmit). Ack
2079 * retransmissions since we may not have any data to send */
2080 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
2082 tcp_program_ack (tc);
2083 error = TCP_ERROR_SEGMENT_OLD;
2087 /* Chop off the bytes in the past and see if what is left
2088 * can be enqueued in order */
2089 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
2090 n_data_bytes -= n_bytes_to_drop;
2091 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
2092 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
2094 error = TCP_ERROR_SEGMENT_OLD;
2100 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
2101 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
2102 tcp_program_dupack (tc);
2103 TCP_EVT (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
2104 tc->errors.above_data_wnd += seq_gt (vnet_buffer (b)->tcp.seq_end,
2105 tc->rcv_las + tc->rcv_wnd);
2111 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
2112 * segments can be enqueued after fifo tail offset changes. */
2113 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
2114 if (tcp_can_delack (tc))
2116 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
2117 tcp_timer_set (tc, TCP_TIMER_DELACK, tcp_cfg.delack_time);
2121 tcp_program_ack (tc);
2129 tcp_header_t tcp_header;
2130 tcp_connection_t tcp_connection;
2134 format_tcp_rx_trace (u8 * s, va_list * args)
2136 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2137 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2138 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2139 tcp_connection_t *tc = &t->tcp_connection;
2140 u32 indent = format_get_indent (s);
2142 s = format (s, "%U state %U\n%U%U", format_tcp_connection_id, tc,
2143 format_tcp_state, tc->state, format_white_space, indent,
2144 format_tcp_header, &t->tcp_header, 128);
2150 format_tcp_rx_trace_short (u8 * s, va_list * args)
2152 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2153 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2154 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2156 s = format (s, "%d -> %d (%U)",
2157 clib_net_to_host_u16 (t->tcp_header.dst_port),
2158 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2159 t->tcp_connection.state);
2165 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2166 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2170 clib_memcpy_fast (&t0->tcp_connection, tc0,
2171 sizeof (t0->tcp_connection));
2175 th0 = tcp_buffer_hdr (b0);
2177 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2181 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2182 vlib_frame_t * frame, u8 is_ip4)
2186 n_left = frame->n_vectors;
2187 from = vlib_frame_vector_args (frame);
2191 tcp_connection_t *tc0;
2198 b0 = vlib_get_buffer (vm, bi0);
2200 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2202 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2203 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2205 th0 = tcp_buffer_hdr (b0);
2206 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2215 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2216 u8 is_ip4, u32 evt, u32 val)
2219 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2221 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2224 #define tcp_maybe_inc_counter(node_id, err, count) \
2226 if (next0 != tcp_next_drop (is_ip4)) \
2227 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2228 tcp6_##node_id##_node.index, is_ip4, err, \
2231 #define tcp_inc_counter(node_id, err, count) \
2232 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2233 tcp6_##node_id##_node.index, is_ip4, \
2235 #define tcp_maybe_inc_err_counter(cnts, err) \
2237 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2239 #define tcp_inc_err_counter(cnts, err, val) \
2243 #define tcp_store_err_counters(node_id, cnts) \
2246 for (i = 0; i < TCP_N_ERROR; i++) \
2248 tcp_inc_counter(node_id, i, cnts[i]); \
2253 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2254 vlib_frame_t * frame, int is_ip4)
2256 u32 thread_index = vm->thread_index, errors = 0;
2257 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2258 u32 n_left_from, *from, *first_buffer;
2259 u16 err_counters[TCP_N_ERROR] = { 0 };
2261 if (node->flags & VLIB_NODE_FLAG_TRACE)
2262 tcp_established_trace_frame (vm, node, frame, is_ip4);
2264 first_buffer = from = vlib_frame_vector_args (frame);
2265 n_left_from = frame->n_vectors;
2267 while (n_left_from > 0)
2269 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2272 tcp_connection_t *tc0;
2274 if (n_left_from > 1)
2277 pb = vlib_get_buffer (vm, from[1]);
2278 vlib_prefetch_buffer_header (pb, LOAD);
2279 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2286 b0 = vlib_get_buffer (vm, bi0);
2287 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2290 if (PREDICT_FALSE (tc0 == 0))
2292 error0 = TCP_ERROR_INVALID_CONNECTION;
2296 th0 = tcp_buffer_hdr (b0);
2298 /* TODO header prediction fast path */
2300 /* 1-4: check SEQ, RST, SYN */
2301 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2303 TCP_EVT (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2307 /* 5: check the ACK field */
2308 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2311 /* 6: check the URG bit TODO */
2313 /* 7: process the segment text */
2314 if (vnet_buffer (b0)->tcp.data_len)
2315 error0 = tcp_segment_rcv (wrk, tc0, b0);
2317 /* 8: check the FIN bit */
2318 if (PREDICT_FALSE (tcp_is_fin (th0)))
2319 tcp_rcv_fin (wrk, tc0, b0, &error0);
2322 tcp_inc_err_counter (err_counters, error0, 1);
2325 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2327 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2328 tcp_store_err_counters (established, err_counters);
2329 tcp_handle_postponed_dequeues (wrk);
2330 tcp_handle_disconnects (wrk);
2331 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2333 return frame->n_vectors;
2336 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2337 vlib_node_runtime_t * node,
2338 vlib_frame_t * from_frame)
2340 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2343 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2344 vlib_node_runtime_t * node,
2345 vlib_frame_t * from_frame)
2347 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2351 VLIB_REGISTER_NODE (tcp4_established_node) =
2353 .name = "tcp4-established",
2354 /* Takes a vector of packets. */
2355 .vector_size = sizeof (u32),
2356 .n_errors = TCP_N_ERROR,
2357 .error_strings = tcp_error_strings,
2358 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2361 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2362 foreach_tcp_state_next
2365 .format_trace = format_tcp_rx_trace_short,
2370 VLIB_REGISTER_NODE (tcp6_established_node) =
2372 .name = "tcp6-established",
2373 /* Takes a vector of packets. */
2374 .vector_size = sizeof (u32),
2375 .n_errors = TCP_N_ERROR,
2376 .error_strings = tcp_error_strings,
2377 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2380 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2381 foreach_tcp_state_next
2384 .format_trace = format_tcp_rx_trace_short,
2390 tcp_lookup_is_valid (tcp_connection_t * tc, vlib_buffer_t * b,
2393 transport_connection_t *tmp = 0;
2400 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2403 u8 is_ip_valid = 0, val_l, val_r;
2405 if (tc->connection.is_ip4)
2407 ip4_header_t *ip4_hdr = (ip4_header_t *) vlib_buffer_get_current (b);
2409 val_l = !ip4_address_compare (&ip4_hdr->dst_address,
2410 &tc->connection.lcl_ip.ip4);
2411 val_l = val_l || ip_is_zero (&tc->connection.lcl_ip, 1);
2412 val_r = !ip4_address_compare (&ip4_hdr->src_address,
2413 &tc->connection.rmt_ip.ip4);
2414 val_r = val_r || tc->state == TCP_STATE_LISTEN;
2415 is_ip_valid = val_l && val_r;
2419 ip6_header_t *ip6_hdr = (ip6_header_t *) vlib_buffer_get_current (b);
2421 val_l = !ip6_address_compare (&ip6_hdr->dst_address,
2422 &tc->connection.lcl_ip.ip6);
2423 val_l = val_l || ip_is_zero (&tc->connection.lcl_ip, 0);
2424 val_r = !ip6_address_compare (&ip6_hdr->src_address,
2425 &tc->connection.rmt_ip.ip6);
2426 val_r = val_r || tc->state == TCP_STATE_LISTEN;
2427 is_ip_valid = val_l && val_r;
2430 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2431 && (tc->state == TCP_STATE_LISTEN
2432 || tc->c_rmt_port == hdr->src_port) && is_ip_valid);
2436 handle = session_lookup_half_open_handle (&tc->connection);
2437 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2438 tc->c_proto, tc->c_is_ip4);
2442 if (tmp->lcl_port == hdr->dst_port
2443 && tmp->rmt_port == hdr->src_port)
2445 TCP_DBG ("half-open is valid!");
2454 * Lookup transport connection
2456 static tcp_connection_t *
2457 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2461 transport_connection_t *tconn;
2462 tcp_connection_t *tc;
2467 ip4 = vlib_buffer_get_current (b);
2468 tcp = ip4_next_header (ip4);
2469 tconn = session_lookup_connection_wt4 (fib_index,
2474 TRANSPORT_PROTO_TCP,
2475 thread_index, &is_filtered);
2476 tc = tcp_get_connection_from_transport (tconn);
2477 ASSERT (tcp_lookup_is_valid (tc, b, tcp));
2482 ip6 = vlib_buffer_get_current (b);
2483 tcp = ip6_next_header (ip6);
2484 tconn = session_lookup_connection_wt6 (fib_index,
2489 TRANSPORT_PROTO_TCP,
2490 thread_index, &is_filtered);
2491 tc = tcp_get_connection_from_transport (tconn);
2492 ASSERT (tcp_lookup_is_valid (tc, b, tcp));
2497 static tcp_connection_t *
2498 tcp_lookup_listener (vlib_buffer_t * b, u32 fib_index, int is_ip4)
2504 ip4_header_t *ip4 = vlib_buffer_get_current (b);
2505 tcp_header_t *tcp = tcp_buffer_hdr (b);
2506 s = session_lookup_listener4 (fib_index,
2508 tcp->dst_port, TRANSPORT_PROTO_TCP, 1);
2512 ip6_header_t *ip6 = vlib_buffer_get_current (b);
2513 tcp_header_t *tcp = tcp_buffer_hdr (b);
2514 s = session_lookup_listener6 (fib_index,
2516 tcp->dst_port, TRANSPORT_PROTO_TCP, 1);
2519 if (PREDICT_TRUE (s != 0))
2520 return tcp_get_connection_from_transport (transport_get_listener
2521 (TRANSPORT_PROTO_TCP,
2522 s->connection_index));
2528 tcp_check_tx_offload (tcp_connection_t * tc, int is_ipv4)
2530 vnet_main_t *vnm = vnet_get_main ();
2531 const dpo_id_t *dpo;
2532 const load_balance_t *lb;
2533 vnet_hw_interface_t *hw_if;
2534 u32 sw_if_idx, lb_idx;
2538 ip4_address_t *dst_addr = &(tc->c_rmt_ip.ip4);
2539 lb_idx = ip4_fib_forwarding_lookup (tc->c_fib_index, dst_addr);
2543 ip6_address_t *dst_addr = &(tc->c_rmt_ip.ip6);
2544 lb_idx = ip6_fib_table_fwding_lookup (tc->c_fib_index, dst_addr);
2547 lb = load_balance_get (lb_idx);
2548 if (PREDICT_FALSE (lb->lb_n_buckets > 1))
2550 dpo = load_balance_get_bucket_i (lb, 0);
2552 sw_if_idx = dpo_get_urpf (dpo);
2553 if (PREDICT_FALSE (sw_if_idx == ~0))
2556 hw_if = vnet_get_sup_hw_interface (vnm, sw_if_idx);
2557 if (hw_if->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO)
2558 tc->cfg_flags |= TCP_CFG_F_TSO;
2562 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2563 vlib_frame_t * from_frame, int is_ip4)
2565 u32 n_left_from, *from, *first_buffer, errors = 0;
2566 u32 my_thread_index = vm->thread_index;
2567 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2569 from = first_buffer = vlib_frame_vector_args (from_frame);
2570 n_left_from = from_frame->n_vectors;
2572 while (n_left_from > 0)
2574 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2575 tcp_connection_t *tc0, *new_tc0;
2576 tcp_header_t *tcp0 = 0;
2584 b0 = vlib_get_buffer (vm, bi0);
2586 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2587 if (PREDICT_FALSE (tc0 == 0))
2589 error0 = TCP_ERROR_INVALID_CONNECTION;
2593 /* Half-open completed recently but the connection was't removed
2594 * yet by the owning thread */
2595 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2597 /* Make sure the connection actually exists */
2598 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2599 my_thread_index, is_ip4));
2600 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2604 ack0 = vnet_buffer (b0)->tcp.ack_number;
2605 seq0 = vnet_buffer (b0)->tcp.seq_number;
2606 tcp0 = tcp_buffer_hdr (b0);
2608 /* Crude check to see if the connection handle does not match
2609 * the packet. Probably connection just switched to established */
2610 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2611 || tcp0->src_port != tc0->c_rmt_port))
2613 error0 = TCP_ERROR_INVALID_CONNECTION;
2617 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2618 && !tcp_syn (tcp0)))
2620 error0 = TCP_ERROR_SEGMENT_INVALID;
2624 /* SYNs consume sequence numbers */
2625 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2628 * 1. check the ACK bit
2632 * If the ACK bit is set
2633 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2634 * the RST bit is set, if so drop the segment and return)
2635 * <SEQ=SEG.ACK><CTL=RST>
2636 * and discard the segment. Return.
2637 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2641 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2643 if (!tcp_rst (tcp0))
2644 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2645 error0 = TCP_ERROR_RCV_WND;
2649 /* Make sure ACK is valid */
2650 if (seq_gt (tc0->snd_una, ack0))
2652 error0 = TCP_ERROR_ACK_INVALID;
2658 * 2. check the RST bit
2663 /* If ACK is acceptable, signal client that peer is not
2664 * willing to accept connection and drop connection*/
2666 tcp_rcv_rst (wrk, tc0);
2667 error0 = TCP_ERROR_RST_RCVD;
2672 * 3. check the security and precedence (skipped)
2676 * 4. check the SYN bit
2679 /* No SYN flag. Drop. */
2680 if (!tcp_syn (tcp0))
2682 error0 = TCP_ERROR_SEGMENT_INVALID;
2687 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2689 error0 = TCP_ERROR_OPTIONS;
2693 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2694 * current thread pool. */
2695 new_tc0 = tcp_connection_alloc_w_base (my_thread_index, tc0);
2696 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2697 new_tc0->irs = seq0;
2698 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2699 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2701 /* If this is not the owning thread, wait for syn retransmit to
2702 * expire and cleanup then */
2703 if (tcp_half_open_connection_cleanup (tc0))
2704 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2706 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2708 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2709 new_tc0->tsval_recent_age = tcp_time_now ();
2712 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2713 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2715 new_tc0->rcv_wscale = 0;
2717 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2718 << new_tc0->snd_wscale;
2719 new_tc0->snd_wl1 = seq0;
2720 new_tc0->snd_wl2 = ack0;
2722 tcp_connection_init_vars (new_tc0);
2724 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2725 if (PREDICT_TRUE (tcp_ack (tcp0)))
2727 /* Our SYN is ACKed: we have iss < ack = snd_una */
2729 /* TODO Dequeue acknowledged segments if we support Fast Open */
2730 new_tc0->snd_una = ack0;
2731 new_tc0->state = TCP_STATE_ESTABLISHED;
2733 /* Make sure las is initialized for the wnd computation */
2734 new_tc0->rcv_las = new_tc0->rcv_nxt;
2736 /* Notify app that we have connection. If session layer can't
2737 * allocate session send reset */
2738 if (session_stream_connect_notify (&new_tc0->connection, 0))
2740 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2741 tcp_connection_cleanup (new_tc0);
2742 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2746 new_tc0->tx_fifo_size =
2747 transport_tx_fifo_size (&new_tc0->connection);
2748 /* Update rtt with the syn-ack sample */
2749 tcp_estimate_initial_rtt (new_tc0);
2750 TCP_EVT (TCP_EVT_SYNACK_RCVD, new_tc0);
2751 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2753 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2756 new_tc0->state = TCP_STATE_SYN_RCVD;
2758 /* Notify app that we have connection */
2759 if (session_stream_connect_notify (&new_tc0->connection, 0))
2761 tcp_connection_cleanup (new_tc0);
2762 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2763 TCP_EVT (TCP_EVT_RST_SENT, tc0);
2764 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2768 new_tc0->tx_fifo_size =
2769 transport_tx_fifo_size (&new_tc0->connection);
2770 new_tc0->rtt_ts = 0;
2771 tcp_init_snd_vars (new_tc0);
2772 tcp_send_synack (new_tc0);
2773 error0 = TCP_ERROR_SYNS_RCVD;
2777 if (!(new_tc0->cfg_flags & TCP_CFG_F_NO_TSO))
2778 tcp_check_tx_offload (new_tc0, is_ip4);
2780 /* Read data, if any */
2781 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2783 clib_warning ("rcvd data in syn-sent");
2784 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2785 if (error0 == TCP_ERROR_ACK_OK)
2786 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2790 /* Send ack now instead of programming it because connection was
2791 * just established and it's not optional. */
2792 tcp_send_ack (new_tc0);
2797 tcp_inc_counter (syn_sent, error0, 1);
2798 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2800 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2801 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2802 clib_memcpy_fast (&t0->tcp_connection, tc0,
2803 sizeof (t0->tcp_connection));
2807 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2809 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2810 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2811 tcp_handle_disconnects (wrk);
2813 return from_frame->n_vectors;
2816 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2817 vlib_node_runtime_t * node,
2818 vlib_frame_t * from_frame)
2820 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2823 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2824 vlib_node_runtime_t * node,
2825 vlib_frame_t * from_frame)
2827 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2831 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2833 .name = "tcp4-syn-sent",
2834 /* Takes a vector of packets. */
2835 .vector_size = sizeof (u32),
2836 .n_errors = TCP_N_ERROR,
2837 .error_strings = tcp_error_strings,
2838 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2841 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2842 foreach_tcp_state_next
2845 .format_trace = format_tcp_rx_trace_short,
2850 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2852 .name = "tcp6-syn-sent",
2853 /* Takes a vector of packets. */
2854 .vector_size = sizeof (u32),
2855 .n_errors = TCP_N_ERROR,
2856 .error_strings = tcp_error_strings,
2857 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2860 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2861 foreach_tcp_state_next
2864 .format_trace = format_tcp_rx_trace_short,
2869 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2870 * as per RFC793 p. 64
2873 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2874 vlib_frame_t * from_frame, int is_ip4)
2876 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2877 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2878 u32 n_left_from, *from, max_dequeue;
2880 from = first_buffer = vlib_frame_vector_args (from_frame);
2881 n_left_from = from_frame->n_vectors;
2883 while (n_left_from > 0)
2885 u32 bi0, error0 = TCP_ERROR_NONE;
2886 tcp_header_t *tcp0 = 0;
2887 tcp_connection_t *tc0;
2895 b0 = vlib_get_buffer (vm, bi0);
2896 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2898 if (PREDICT_FALSE (tc0 == 0))
2900 error0 = TCP_ERROR_INVALID_CONNECTION;
2904 tcp0 = tcp_buffer_hdr (b0);
2905 is_fin0 = tcp_is_fin (tcp0);
2909 if (!(tc0->connection.flags & TRANSPORT_CONNECTION_F_NO_LOOKUP))
2911 tcp_connection_t *tmp;
2912 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2914 if (tmp->state != tc0->state)
2916 if (tc0->state != TCP_STATE_CLOSED)
2917 clib_warning ("state changed");
2924 * Special treatment for CLOSED
2926 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2928 error0 = TCP_ERROR_CONNECTION_CLOSED;
2933 * For all other states (except LISTEN)
2936 /* 1-4: check SEQ, RST, SYN */
2937 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2940 /* 5: check the ACK field */
2943 case TCP_STATE_SYN_RCVD:
2945 /* Make sure the segment is exactly right */
2946 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2948 tcp_send_reset_w_pkt (tc0, b0, thread_index, is_ip4);
2949 error0 = TCP_ERROR_SEGMENT_INVALID;
2954 * If the segment acknowledgment is not acceptable, form a
2956 * <SEQ=SEG.ACK><CTL=RST>
2959 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2961 tcp_send_reset_w_pkt (tc0, b0, thread_index, is_ip4);
2962 error0 = TCP_ERROR_SEGMENT_INVALID;
2966 /* Update rtt and rto */
2967 tcp_estimate_initial_rtt (tc0);
2968 tcp_connection_tx_pacer_update (tc0);
2970 /* Switch state to ESTABLISHED */
2971 tc0->state = TCP_STATE_ESTABLISHED;
2972 TCP_EVT (TCP_EVT_STATE_CHANGE, tc0);
2974 if (!(tc0->cfg_flags & TCP_CFG_F_NO_TSO))
2975 tcp_check_tx_offload (tc0, is_ip4);
2977 /* Initialize session variables */
2978 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2979 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2980 << tc0->rcv_opts.wscale;
2981 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2982 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2984 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2985 tcp_retransmit_timer_reset (tc0);
2986 if (session_stream_accept_notify (&tc0->connection))
2988 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2989 tcp_send_reset (tc0);
2990 session_transport_delete_notify (&tc0->connection);
2991 tcp_connection_cleanup (tc0);
2994 error0 = TCP_ERROR_ACK_OK;
2996 case TCP_STATE_ESTABLISHED:
2997 /* We can get packets in established state here because they
2998 * were enqueued before state change */
2999 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
3003 case TCP_STATE_FIN_WAIT_1:
3004 /* In addition to the processing for the ESTABLISHED state, if
3005 * our FIN is now acknowledged then enter FIN-WAIT-2 and
3006 * continue processing in that state. */
3007 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
3010 /* Still have to send the FIN */
3011 if (tc0->flags & TCP_CONN_FINPNDG)
3013 /* TX fifo finally drained */
3014 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
3015 if (max_dequeue <= tc0->burst_acked)
3017 /* If a fin was received and data was acked extend wait */
3018 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
3019 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
3020 tcp_cfg.closewait_time);
3022 /* If FIN is ACKed */
3023 else if (tc0->snd_una == tc0->snd_nxt)
3025 /* Stop all retransmit timers because we have nothing more
3027 tcp_connection_timers_reset (tc0);
3029 /* We already have a FIN but didn't transition to CLOSING
3030 * because of outstanding tx data. Close the connection. */
3031 if (tc0->flags & TCP_CONN_FINRCVD)
3033 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
3034 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE,
3035 tcp_cfg.cleanup_time);
3036 session_transport_closed_notify (&tc0->connection);
3040 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
3041 /* Enable waitclose because we're willing to wait for peer's
3042 * FIN but not indefinitely. */
3043 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait2_time);
3045 /* Don't try to deq the FIN acked */
3046 if (tc0->burst_acked > 1)
3047 session_tx_fifo_dequeue_drop (&tc0->connection,
3048 tc0->burst_acked - 1);
3049 tc0->burst_acked = 0;
3052 case TCP_STATE_FIN_WAIT_2:
3053 /* In addition to the processing for the ESTABLISHED state, if
3054 * the retransmission queue is empty, the user's CLOSE can be
3055 * acknowledged ("ok") but do not delete the TCB. */
3056 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
3058 tc0->burst_acked = 0;
3060 case TCP_STATE_CLOSE_WAIT:
3061 /* Do the same processing as for the ESTABLISHED state. */
3062 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
3065 if (!(tc0->flags & TCP_CONN_FINPNDG))
3068 /* Still have outstanding tx data */
3069 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
3070 if (max_dequeue > tc0->burst_acked)
3074 tcp_connection_timers_reset (tc0);
3075 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
3076 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
3078 case TCP_STATE_CLOSING:
3079 /* In addition to the processing for the ESTABLISHED state, if
3080 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
3081 * otherwise ignore the segment. */
3082 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
3085 if (tc0->snd_una != tc0->snd_nxt)
3088 tcp_connection_timers_reset (tc0);
3089 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
3090 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3091 session_transport_closed_notify (&tc0->connection);
3095 case TCP_STATE_LAST_ACK:
3096 /* The only thing that [should] arrive in this state is an
3097 * acknowledgment of our FIN. If our FIN is now acknowledged,
3098 * delete the TCB, enter the CLOSED state, and return. */
3100 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
3103 /* Apparently our ACK for the peer's FIN was lost */
3104 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
3110 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
3111 session_transport_closed_notify (&tc0->connection);
3113 /* Don't free the connection from the data path since
3114 * we can't ensure that we have no packets already enqueued
3115 * to output. Rely instead on the waitclose timer */
3116 tcp_connection_timers_reset (tc0);
3117 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
3122 case TCP_STATE_TIME_WAIT:
3123 /* The only thing that can arrive in this state is a
3124 * retransmission of the remote FIN. Acknowledge it, and restart
3125 * the 2 MSL timeout. */
3127 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
3133 tcp_program_ack (tc0);
3134 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3142 /* 6: check the URG bit TODO */
3144 /* 7: process the segment text */
3147 case TCP_STATE_ESTABLISHED:
3148 case TCP_STATE_FIN_WAIT_1:
3149 case TCP_STATE_FIN_WAIT_2:
3150 if (vnet_buffer (b0)->tcp.data_len)
3151 error0 = tcp_segment_rcv (wrk, tc0, b0);
3153 case TCP_STATE_CLOSE_WAIT:
3154 case TCP_STATE_CLOSING:
3155 case TCP_STATE_LAST_ACK:
3156 case TCP_STATE_TIME_WAIT:
3157 /* This should not occur, since a FIN has been received from the
3158 * remote side. Ignore the segment text. */
3162 /* 8: check the FIN bit */
3166 TCP_EVT (TCP_EVT_FIN_RCVD, tc0);
3170 case TCP_STATE_ESTABLISHED:
3171 /* Account for the FIN and send ack */
3173 tcp_program_ack (tc0);
3174 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
3175 tcp_program_disconnect (wrk, tc0);
3176 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
3178 case TCP_STATE_SYN_RCVD:
3179 /* Send FIN-ACK, enter LAST-ACK and because the app was not
3180 * notified yet, set a cleanup timer instead of relying on
3181 * disconnect notify and the implicit close call. */
3182 tcp_connection_timers_reset (tc0);
3185 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
3186 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
3188 case TCP_STATE_CLOSE_WAIT:
3189 case TCP_STATE_CLOSING:
3190 case TCP_STATE_LAST_ACK:
3193 case TCP_STATE_FIN_WAIT_1:
3196 if (tc0->flags & TCP_CONN_FINPNDG)
3198 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
3199 * sending it. Since we already received a fin, do not wait
3201 tc0->flags |= TCP_CONN_FINRCVD;
3202 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
3203 tcp_cfg.closewait_time);
3207 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
3208 tcp_program_ack (tc0);
3209 /* Wait for ACK for our FIN but not forever */
3210 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
3211 tcp_cfg.closing_time);
3214 case TCP_STATE_FIN_WAIT_2:
3215 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
3217 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
3218 tcp_connection_timers_reset (tc0);
3219 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3220 tcp_program_ack (tc0);
3221 session_transport_closed_notify (&tc0->connection);
3223 case TCP_STATE_TIME_WAIT:
3224 /* Remain in the TIME-WAIT state. Restart the time-wait
3227 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3230 error0 = TCP_ERROR_FIN_RCVD;
3234 tcp_inc_counter (rcv_process, error0, 1);
3235 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3237 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3238 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3242 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
3244 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3245 tcp_handle_postponed_dequeues (wrk);
3246 tcp_handle_disconnects (wrk);
3247 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3249 return from_frame->n_vectors;
3252 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
3253 vlib_node_runtime_t * node,
3254 vlib_frame_t * from_frame)
3256 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3259 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
3260 vlib_node_runtime_t * node,
3261 vlib_frame_t * from_frame)
3263 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3267 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3269 .name = "tcp4-rcv-process",
3270 /* Takes a vector of packets. */
3271 .vector_size = sizeof (u32),
3272 .n_errors = TCP_N_ERROR,
3273 .error_strings = tcp_error_strings,
3274 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3277 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3278 foreach_tcp_state_next
3281 .format_trace = format_tcp_rx_trace_short,
3286 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3288 .name = "tcp6-rcv-process",
3289 /* Takes a vector of packets. */
3290 .vector_size = sizeof (u32),
3291 .n_errors = TCP_N_ERROR,
3292 .error_strings = tcp_error_strings,
3293 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3296 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3297 foreach_tcp_state_next
3300 .format_trace = format_tcp_rx_trace_short,
3305 * LISTEN state processing as per RFC 793 p. 65
3308 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3309 vlib_frame_t * from_frame, int is_ip4)
3311 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3312 u32 my_thread_index = vm->thread_index;
3313 tcp_connection_t *tc0;
3315 from = first_buffer = vlib_frame_vector_args (from_frame);
3316 n_left_from = from_frame->n_vectors;
3318 while (n_left_from > 0)
3323 tcp_header_t *th0 = 0;
3324 tcp_connection_t *lc0;
3327 tcp_connection_t *child0;
3328 u32 error0 = TCP_ERROR_NONE;
3334 b0 = vlib_get_buffer (vm, bi0);
3338 ip40 = vlib_buffer_get_current (b0);
3339 th0 = tcp_buffer_hdr (b0);
3343 ip60 = vlib_buffer_get_current (b0);
3344 th0 = tcp_buffer_hdr (b0);
3347 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3348 if (PREDICT_FALSE (lc0 == 0))
3350 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
3352 if (tc0->state != TCP_STATE_TIME_WAIT)
3354 error0 = TCP_ERROR_CREATE_EXISTS;
3357 lc0 = tcp_lookup_listener (b0, tc0->c_fib_index, is_ip4);
3358 /* clean up the old session */
3359 tcp_connection_del (tc0);
3362 /* Create child session. For syn-flood protection use filter */
3364 /* 1. first check for an RST: handled in dispatch */
3365 /* if (tcp_rst (th0))
3369 /* 2. second check for an ACK: handled in dispatch */
3370 /* if (tcp_ack (th0))
3372 tcp_send_reset (b0, is_ip4);
3377 /* 3. check for a SYN (did that already) */
3379 /* Make sure connection wasn't just created */
3380 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3382 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3384 error0 = TCP_ERROR_CREATE_EXISTS;
3388 /* Create child session and send SYN-ACK */
3389 child0 = tcp_connection_alloc (my_thread_index);
3390 child0->c_lcl_port = th0->dst_port;
3391 child0->c_rmt_port = th0->src_port;
3392 child0->c_is_ip4 = is_ip4;
3393 child0->state = TCP_STATE_SYN_RCVD;
3394 child0->c_fib_index = lc0->c_fib_index;
3395 child0->cc_algo = lc0->cc_algo;
3399 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3400 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3404 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3405 sizeof (ip6_address_t));
3406 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3407 sizeof (ip6_address_t));
3410 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3412 error0 = TCP_ERROR_OPTIONS;
3413 tcp_connection_free (child0);
3417 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3418 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3419 child0->rcv_las = child0->rcv_nxt;
3420 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3422 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3423 * segments are used to initialize PAWS. */
3424 if (tcp_opts_tstamp (&child0->rcv_opts))
3426 child0->tsval_recent = child0->rcv_opts.tsval;
3427 child0->tsval_recent_age = tcp_time_now ();
3430 if (tcp_opts_wscale (&child0->rcv_opts))
3431 child0->snd_wscale = child0->rcv_opts.wscale;
3433 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3434 << child0->snd_wscale;
3435 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3436 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3438 tcp_connection_init_vars (child0);
3439 child0->rto = TCP_RTO_MIN;
3441 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3442 lc0->c_thread_index, 0 /* notify */ ))
3444 tcp_connection_cleanup (child0);
3445 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3449 TCP_EVT (TCP_EVT_SYN_RCVD, child0, 1);
3450 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3451 tcp_send_synack (child0);
3455 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3457 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3458 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3459 clib_memcpy_fast (&t0->tcp_connection, lc0,
3460 sizeof (t0->tcp_connection));
3463 n_syns += (error0 == TCP_ERROR_NONE);
3466 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3467 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3469 return from_frame->n_vectors;
3472 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3473 vlib_frame_t * from_frame)
3475 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3478 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3479 vlib_frame_t * from_frame)
3481 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3485 VLIB_REGISTER_NODE (tcp4_listen_node) =
3487 .name = "tcp4-listen",
3488 /* Takes a vector of packets. */
3489 .vector_size = sizeof (u32),
3490 .n_errors = TCP_N_ERROR,
3491 .error_strings = tcp_error_strings,
3492 .n_next_nodes = TCP_LISTEN_N_NEXT,
3495 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3496 foreach_tcp_state_next
3499 .format_trace = format_tcp_rx_trace_short,
3504 VLIB_REGISTER_NODE (tcp6_listen_node) =
3506 .name = "tcp6-listen",
3507 /* Takes a vector of packets. */
3508 .vector_size = sizeof (u32),
3509 .n_errors = TCP_N_ERROR,
3510 .error_strings = tcp_error_strings,
3511 .n_next_nodes = TCP_LISTEN_N_NEXT,
3514 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3515 foreach_tcp_state_next
3518 .format_trace = format_tcp_rx_trace_short,
3522 typedef enum _tcp_input_next
3524 TCP_INPUT_NEXT_DROP,
3525 TCP_INPUT_NEXT_LISTEN,
3526 TCP_INPUT_NEXT_RCV_PROCESS,
3527 TCP_INPUT_NEXT_SYN_SENT,
3528 TCP_INPUT_NEXT_ESTABLISHED,
3529 TCP_INPUT_NEXT_RESET,
3530 TCP_INPUT_NEXT_PUNT,
3534 #define foreach_tcp4_input_next \
3535 _ (DROP, "ip4-drop") \
3536 _ (LISTEN, "tcp4-listen") \
3537 _ (RCV_PROCESS, "tcp4-rcv-process") \
3538 _ (SYN_SENT, "tcp4-syn-sent") \
3539 _ (ESTABLISHED, "tcp4-established") \
3540 _ (RESET, "tcp4-reset") \
3541 _ (PUNT, "ip4-punt")
3543 #define foreach_tcp6_input_next \
3544 _ (DROP, "ip6-drop") \
3545 _ (LISTEN, "tcp6-listen") \
3546 _ (RCV_PROCESS, "tcp6-rcv-process") \
3547 _ (SYN_SENT, "tcp6-syn-sent") \
3548 _ (ESTABLISHED, "tcp6-established") \
3549 _ (RESET, "tcp6-reset") \
3550 _ (PUNT, "ip6-punt")
3552 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3555 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3556 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3558 tcp_connection_t *tc;
3563 for (i = 0; i < n_bufs; i++)
3565 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3567 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3568 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3570 tcp = vlib_buffer_get_current (bs[i]);
3571 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3577 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3579 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3581 *next = TCP_INPUT_NEXT_DROP;
3583 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3585 *next = TCP_INPUT_NEXT_PUNT;
3586 *error = TCP_ERROR_PUNT;
3590 *next = TCP_INPUT_NEXT_RESET;
3591 *error = TCP_ERROR_NO_LISTENER;
3595 always_inline tcp_connection_t *
3596 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3597 u8 is_ip4, u8 is_nolookup)
3599 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3600 int n_advance_bytes, n_data_bytes;
3601 transport_connection_t *tc;
3607 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3608 int ip_hdr_bytes = ip4_header_bytes (ip4);
3609 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3611 *error = TCP_ERROR_LENGTH;
3614 tcp = ip4_next_header (ip4);
3615 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3616 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3617 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3619 /* Length check. Checksum computed by ipx_local no need to compute again */
3620 if (PREDICT_FALSE (n_data_bytes < 0))
3622 *error = TCP_ERROR_LENGTH;
3627 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3628 &ip4->src_address, tcp->dst_port,
3630 TRANSPORT_PROTO_TCP, thread_index,
3635 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3636 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3638 *error = TCP_ERROR_LENGTH;
3641 tcp = ip6_next_header (ip6);
3642 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3643 n_advance_bytes = tcp_header_bytes (tcp);
3644 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3646 n_advance_bytes += sizeof (ip6[0]);
3648 if (PREDICT_FALSE (n_data_bytes < 0))
3650 *error = TCP_ERROR_LENGTH;
3657 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3659 ip4_main_t *im = &ip4_main;
3660 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3661 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3664 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3666 tcp->dst_port, tcp->src_port,
3667 TRANSPORT_PROTO_TCP,
3668 thread_index, &result);
3674 (transport_connection_t *) tcp_connection_get (vnet_buffer (b)->
3675 tcp.connection_index,
3678 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3679 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3680 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3681 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3682 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3684 vnet_buffer (b)->tcp.flags = 0;
3686 *error = result ? TCP_ERROR_NONE + result : *error;
3688 return tcp_get_connection_from_transport (tc);
3692 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3693 vlib_buffer_t * b, u16 * next,
3694 vlib_node_runtime_t * error_node)
3700 tcp = tcp_buffer_hdr (b);
3701 flags = tcp->flags & filter_flags;
3702 *next = tm->dispatch_table[tc->state][flags].next;
3703 error = tm->dispatch_table[tc->state][flags].error;
3706 if (PREDICT_FALSE (error != TCP_ERROR_NONE))
3708 b->error = error_node->errors[error];
3709 if (error == TCP_ERROR_DISPATCH)
3710 clib_warning ("tcp conn %u disp error state %U flags %U",
3711 tc->c_c_index, format_tcp_state, tc->state,
3712 format_tcp_flags, (int) flags);
3717 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3718 vlib_frame_t * frame, int is_ip4, u8 is_nolookup)
3720 u32 n_left_from, *from, thread_index = vm->thread_index;
3721 tcp_main_t *tm = vnet_get_tcp_main ();
3722 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3723 u16 nexts[VLIB_FRAME_SIZE], *next;
3724 vlib_node_runtime_t *error_node;
3726 tcp_set_time_now (tcp_get_worker (thread_index));
3728 error_node = vlib_node_get_runtime (vm, tcp_node_index (input, is_ip4));
3729 from = vlib_frame_vector_args (frame);
3730 n_left_from = frame->n_vectors;
3731 vlib_get_buffers (vm, from, bufs, n_left_from);
3736 while (n_left_from >= 4)
3738 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3739 tcp_connection_t *tc0, *tc1;
3742 vlib_prefetch_buffer_header (b[2], STORE);
3743 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3745 vlib_prefetch_buffer_header (b[3], STORE);
3746 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3749 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3751 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3753 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4,
3756 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3758 ASSERT (tcp_lookup_is_valid (tc0, b[0], tcp_buffer_hdr (b[0])));
3759 ASSERT (tcp_lookup_is_valid (tc1, b[1], tcp_buffer_hdr (b[1])));
3761 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3762 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3764 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], error_node);
3765 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], error_node);
3769 if (PREDICT_TRUE (tc0 != 0))
3771 ASSERT (tcp_lookup_is_valid (tc0, b[0], tcp_buffer_hdr (b[0])));
3772 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3773 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], error_node);
3777 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3778 b[0]->error = error_node->errors[error0];
3781 if (PREDICT_TRUE (tc1 != 0))
3783 ASSERT (tcp_lookup_is_valid (tc1, b[1], tcp_buffer_hdr (b[1])));
3784 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3785 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], error_node);
3789 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3790 b[1]->error = error_node->errors[error1];
3798 while (n_left_from > 0)
3800 tcp_connection_t *tc0;
3801 u32 error0 = TCP_ERROR_NO_LISTENER;
3803 if (n_left_from > 1)
3805 vlib_prefetch_buffer_header (b[1], STORE);
3806 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3809 next[0] = TCP_INPUT_NEXT_DROP;
3810 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3812 if (PREDICT_TRUE (tc0 != 0))
3814 ASSERT (tcp_lookup_is_valid (tc0, b[0], tcp_buffer_hdr (b[0])));
3815 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3816 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], error_node);
3820 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3821 b[0]->error = error_node->errors[error0];
3829 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3830 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3832 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3833 return frame->n_vectors;
3836 VLIB_NODE_FN (tcp4_input_nolookup_node) (vlib_main_t * vm,
3837 vlib_node_runtime_t * node,
3838 vlib_frame_t * from_frame)
3840 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3841 1 /* is_nolookup */ );
3844 VLIB_NODE_FN (tcp6_input_nolookup_node) (vlib_main_t * vm,
3845 vlib_node_runtime_t * node,
3846 vlib_frame_t * from_frame)
3848 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3849 1 /* is_nolookup */ );
3853 VLIB_REGISTER_NODE (tcp4_input_nolookup_node) =
3855 .name = "tcp4-input-nolookup",
3856 /* Takes a vector of packets. */
3857 .vector_size = sizeof (u32),
3858 .n_errors = TCP_N_ERROR,
3859 .error_strings = tcp_error_strings,
3860 .n_next_nodes = TCP_INPUT_N_NEXT,
3863 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3864 foreach_tcp4_input_next
3867 .format_buffer = format_tcp_header,
3868 .format_trace = format_tcp_rx_trace,
3873 VLIB_REGISTER_NODE (tcp6_input_nolookup_node) =
3875 .name = "tcp6-input-nolookup",
3876 /* Takes a vector of packets. */
3877 .vector_size = sizeof (u32),
3878 .n_errors = TCP_N_ERROR,
3879 .error_strings = tcp_error_strings,
3880 .n_next_nodes = TCP_INPUT_N_NEXT,
3883 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3884 foreach_tcp6_input_next
3887 .format_buffer = format_tcp_header,
3888 .format_trace = format_tcp_rx_trace,
3892 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3893 vlib_frame_t * from_frame)
3895 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3896 0 /* is_nolookup */ );
3899 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3900 vlib_frame_t * from_frame)
3902 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3903 0 /* is_nolookup */ );
3907 VLIB_REGISTER_NODE (tcp4_input_node) =
3909 .name = "tcp4-input",
3910 /* Takes a vector of packets. */
3911 .vector_size = sizeof (u32),
3912 .n_errors = TCP_N_ERROR,
3913 .error_strings = tcp_error_strings,
3914 .n_next_nodes = TCP_INPUT_N_NEXT,
3917 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3918 foreach_tcp4_input_next
3921 .format_buffer = format_tcp_header,
3922 .format_trace = format_tcp_rx_trace,
3927 VLIB_REGISTER_NODE (tcp6_input_node) =
3929 .name = "tcp6-input",
3930 /* Takes a vector of packets. */
3931 .vector_size = sizeof (u32),
3932 .n_errors = TCP_N_ERROR,
3933 .error_strings = tcp_error_strings,
3934 .n_next_nodes = TCP_INPUT_N_NEXT,
3937 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3938 foreach_tcp6_input_next
3941 .format_buffer = format_tcp_header,
3942 .format_trace = format_tcp_rx_trace,
3946 #ifndef CLIB_MARCH_VARIANT
3948 tcp_dispatch_table_init (tcp_main_t * tm)
3951 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3952 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3954 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3955 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3958 #define _(t,f,n,e) \
3960 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3961 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3964 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3965 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3966 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3967 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3968 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3969 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3970 TCP_ERROR_ACK_INVALID);
3971 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3972 TCP_ERROR_SEGMENT_INVALID);
3973 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3974 TCP_ERROR_SEGMENT_INVALID);
3975 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3976 TCP_ERROR_INVALID_CONNECTION);
3977 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3978 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3979 TCP_ERROR_SEGMENT_INVALID);
3980 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3981 TCP_ERROR_SEGMENT_INVALID);
3982 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3983 TCP_ERROR_SEGMENT_INVALID);
3984 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3985 TCP_ERROR_SEGMENT_INVALID);
3986 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3987 TCP_ERROR_SEGMENT_INVALID);
3988 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3989 TCP_ERROR_SEGMENT_INVALID);
3990 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3991 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3992 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3993 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3994 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3995 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3997 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3998 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4000 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
4002 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
4003 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4004 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4005 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4007 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
4009 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
4010 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4011 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
4013 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
4014 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4015 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
4016 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4017 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
4018 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4019 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
4020 /* SYN-ACK for a SYN */
4021 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
4023 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
4024 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
4025 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
4027 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
4028 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
4030 /* ACK for for established connection -> tcp-established. */
4031 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
4032 /* FIN for for established connection -> tcp-established. */
4033 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
4034 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
4036 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
4038 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
4039 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
4040 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
4042 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
4043 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
4044 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
4045 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
4046 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
4047 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
4048 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
4049 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
4051 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
4052 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
4054 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
4056 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
4057 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
4058 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
4059 /* ACK or FIN-ACK to our FIN */
4060 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4061 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
4063 /* FIN in reply to our FIN from the other side */
4064 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
4065 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4066 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
4068 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
4069 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4070 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
4071 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4072 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
4073 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4074 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
4076 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
4077 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4078 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4079 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
4081 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4083 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
4084 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4085 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4086 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4088 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
4089 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4090 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4091 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
4093 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4095 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
4096 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4097 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4098 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4100 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4101 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4103 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
4105 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
4106 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4107 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
4109 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
4110 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4111 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
4112 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4113 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
4114 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4115 /* FIN confirming that the peer (app) has closed */
4116 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4117 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4118 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4120 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4121 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4123 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4124 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4126 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4127 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4129 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
4130 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4131 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4132 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4134 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
4136 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
4137 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4138 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
4140 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
4141 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4142 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
4143 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4144 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
4145 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4146 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4147 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4149 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4150 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4152 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
4154 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
4155 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4156 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
4157 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4158 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4160 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4161 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
4163 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
4164 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
4165 * incoming segment not containing a RST causes a RST to be sent in
4167 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
4168 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
4169 TCP_ERROR_CONNECTION_CLOSED);
4170 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_CONNECTION_CLOSED);
4171 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_CONNECTION_CLOSED);
4172 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
4173 TCP_ERROR_CONNECTION_CLOSED);
4177 static clib_error_t *
4178 tcp_input_init (vlib_main_t * vm)
4180 clib_error_t *error = 0;
4181 tcp_main_t *tm = vnet_get_tcp_main ();
4183 if ((error = vlib_call_init_function (vm, tcp_init)))
4186 /* Initialize dispatch table. */
4187 tcp_dispatch_table_init (tm);
4192 VLIB_INIT_FUNCTION (tcp_input_init);
4194 #endif /* CLIB_MARCH_VARIANT */
4197 * fd.io coding-style-patch-verification: ON
4200 * eval: (c-set-style "gnu")