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 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
272 * It first verifies if segment has a wrapped sequence number (PAWS) and then
273 * does the processing associated to the first four steps (ignoring security
274 * and precedence): sequence number, rst bit and syn bit checks.
276 * @return 0 if segments passes validation.
279 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
280 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
282 /* We could get a burst of RSTs interleaved with acks */
283 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
285 tcp_send_reset (tc0);
286 *error0 = TCP_ERROR_CONNECTION_CLOSED;
290 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
292 *error0 = TCP_ERROR_SEGMENT_INVALID;
296 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
298 *error0 = TCP_ERROR_OPTIONS;
302 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
304 *error0 = TCP_ERROR_PAWS;
305 TCP_EVT (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
306 vnet_buffer (b0)->tcp.seq_end);
308 /* If it just so happens that a segment updates tsval_recent for a
309 * segment over 24 days old, invalidate tsval_recent. */
310 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
311 tcp_time_now_w_thread (tc0->c_thread_index)))
313 tc0->tsval_recent = tc0->rcv_opts.tsval;
314 clib_warning ("paws failed: 24-day old segment");
316 /* Drop after ack if not rst. Resets can fail paws check as per
317 * RFC 7323 sec. 5.2: When an <RST> segment is received, it MUST NOT
318 * be subjected to the PAWS check by verifying an acceptable value in
320 else if (!tcp_rst (th0))
322 tcp_program_ack (tc0);
323 TCP_EVT (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
328 /* 1st: check sequence number */
329 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
330 vnet_buffer (b0)->tcp.seq_end))
332 /* SYN/SYN-ACK retransmit */
334 && vnet_buffer (b0)->tcp.seq_number == tc0->rcv_nxt - 1)
336 tcp_options_parse (th0, &tc0->rcv_opts, 1);
337 if (tc0->state == TCP_STATE_SYN_RCVD)
339 tcp_send_synack (tc0);
340 TCP_EVT (TCP_EVT_SYN_RCVD, tc0, 0);
341 *error0 = TCP_ERROR_SYNS_RCVD;
345 tcp_program_ack (tc0);
346 TCP_EVT (TCP_EVT_SYNACK_RCVD, tc0);
347 *error0 = TCP_ERROR_SYN_ACKS_RCVD;
352 /* If our window is 0 and the packet is in sequence, let it pass
353 * through for ack processing. It should be dropped later. */
354 if (tc0->rcv_wnd < tc0->snd_mss
355 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
358 /* If we entered recovery and peer did so as well, there's a chance that
359 * dup acks won't be acceptable on either end because seq_end may be less
360 * than rcv_las. This can happen if acks are lost in both directions. */
361 if (tcp_in_recovery (tc0)
362 && seq_geq (vnet_buffer (b0)->tcp.seq_number,
363 tc0->rcv_las - tc0->rcv_wnd)
364 && seq_leq (vnet_buffer (b0)->tcp.seq_end,
365 tc0->rcv_nxt + tc0->rcv_wnd))
368 *error0 = TCP_ERROR_RCV_WND;
370 /* If we advertised a zero rcv_wnd and the segment is in the past or the
371 * next one that we expect, it is probably a window probe */
372 if ((tc0->flags & TCP_CONN_ZERO_RWND_SENT)
373 && seq_lt (vnet_buffer (b0)->tcp.seq_end,
374 tc0->rcv_las + tc0->rcv_opts.mss))
375 *error0 = TCP_ERROR_ZERO_RWND;
377 tc0->errors.below_data_wnd += seq_lt (vnet_buffer (b0)->tcp.seq_end,
380 /* If not RST, send dup ack */
383 tcp_program_dupack (tc0);
384 TCP_EVT (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
392 /* 2nd: check the RST bit */
393 if (PREDICT_FALSE (tcp_rst (th0)))
395 tcp_connection_reset (tc0);
396 *error0 = TCP_ERROR_RST_RCVD;
400 /* 3rd: check security and precedence (skip) */
402 /* 4th: check the SYN bit (in window) */
403 if (PREDICT_FALSE (tcp_syn (th0)))
405 /* As per RFC5961 send challenge ack instead of reset */
406 tcp_program_ack (tc0);
407 *error0 = TCP_ERROR_SPURIOUS_SYN;
411 /* If segment in window, save timestamp */
412 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
413 vnet_buffer (b0)->tcp.seq_end);
421 tcp_rcv_ack_no_cc (tcp_connection_t * tc, vlib_buffer_t * b, u32 * error)
423 /* SND.UNA =< SEG.ACK =< SND.NXT */
424 if (!(seq_leq (tc->snd_una, vnet_buffer (b)->tcp.ack_number)
425 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
427 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
428 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
430 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
433 *error = TCP_ERROR_ACK_INVALID;
438 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
439 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
440 *error = TCP_ERROR_ACK_OK;
445 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
447 * Note that although the original article, srtt and rttvar are scaled
448 * to minimize round-off errors, here we don't. Instead, we rely on
449 * better precision time measurements.
451 * TODO support us rtt resolution
454 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
460 err = mrtt - tc->srtt;
462 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
463 * The increase should be bound */
464 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
465 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
466 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
470 /* First measurement. */
472 tc->rttvar = mrtt >> 1;
476 #ifndef CLIB_MARCH_VARIANT
478 tcp_update_rto (tcp_connection_t * tc)
480 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
481 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
483 #endif /* CLIB_MARCH_VARIANT */
486 * Update RTT estimate and RTO timer
488 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
489 * timing. Middle boxes are known to fiddle with TCP options so we
490 * should give higher priority to ACK timing.
492 * This should be called only if previously sent bytes have been acked.
494 * return 1 if valid rtt 0 otherwise
497 tcp_update_rtt (tcp_connection_t * tc, tcp_rate_sample_t * rs, u32 ack)
501 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
502 * RTT because they're ambiguous. */
503 if (tcp_in_cong_recovery (tc))
505 /* Accept rtt estimates for samples that have not been retransmitted */
506 if ((tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
507 && !(rs->flags & TCP_BTS_IS_RXT))
509 mrtt = rs->rtt_time * THZ;
515 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
517 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
518 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
519 mrtt = clib_max ((u32) (sample * THZ), 1);
520 /* Allow measuring of a new RTT */
523 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
524 * snd_una, i.e., the left side of the send window:
525 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
526 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
528 u32 now = tcp_tstamp (tc);
529 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
534 /* Ignore dubious measurements */
535 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
538 tcp_estimate_rtt (tc, mrtt);
542 /* If we got here something must've been ACKed so make sure boff is 0,
543 * even if mrtt is not valid since we update the rto lower */
551 tcp_estimate_initial_rtt (tcp_connection_t * tc)
553 u8 thread_index = vlib_num_workers ()? 1 : 0;
558 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
559 tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001);
560 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
565 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
566 mrtt = clib_max (mrtt, 1);
567 /* Due to retransmits we don't know the initial mrtt */
568 if (tc->rto_boff && mrtt > 1 * THZ)
570 tc->mrtt_us = (f64) mrtt *TCP_TICK;
573 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
574 tcp_estimate_rtt (tc, mrtt);
579 tcp_recovery_no_snd_space (tcp_connection_t * tc)
583 ASSERT (tcp_in_cong_recovery (tc));
585 if (tcp_in_recovery (tc))
586 space = tcp_available_output_snd_space (tc);
588 space = tcp_fastrecovery_prr_snd_space (tc);
590 return (space < tc->snd_mss + tc->burst_acked);
594 * Dequeue bytes for connections that have received acks in last burst
597 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
599 u32 thread_index = wrk->vm->thread_index;
600 u32 *pending_deq_acked;
601 tcp_connection_t *tc;
604 if (!vec_len (wrk->pending_deq_acked))
607 pending_deq_acked = wrk->pending_deq_acked;
608 for (i = 0; i < vec_len (pending_deq_acked); i++)
610 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
611 tc->flags &= ~TCP_CONN_DEQ_PENDING;
615 /* Dequeue the newly ACKed bytes */
616 session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
617 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
619 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
621 if (seq_leq (tc->psh_seq, tc->snd_una))
622 tc->flags &= ~TCP_CONN_PSH_PENDING;
625 /* If everything has been acked, stop retransmit timer
626 * otherwise update. */
627 tcp_retransmit_timer_update (tc);
629 /* Update pacer based on our new cwnd estimate */
630 tcp_connection_tx_pacer_update (tc);
633 /* Reset the pacer if we've been idle, i.e., no data sent or if
634 * we're in recovery and snd space constrained */
635 if (tc->data_segs_out == tc->prev_dsegs_out
636 || (tcp_in_cong_recovery (tc) && tcp_recovery_no_snd_space (tc)))
637 transport_connection_tx_pacer_reset_bucket (&tc->connection);
639 tc->prev_dsegs_out = tc->data_segs_out;
642 _vec_len (wrk->pending_deq_acked) = 0;
646 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
648 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
650 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
651 tc->flags |= TCP_CONN_DEQ_PENDING;
653 tc->burst_acked += tc->bytes_acked;
656 #ifndef CLIB_MARCH_VARIANT
658 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
660 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
661 return hole - sb->holes;
665 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
667 return hole->end - hole->start;
670 sack_scoreboard_hole_t *
671 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
673 if (index != TCP_INVALID_SACK_HOLE_INDEX)
674 return pool_elt_at_index (sb->holes, index);
678 sack_scoreboard_hole_t *
679 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
681 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
682 return pool_elt_at_index (sb->holes, hole->next);
686 sack_scoreboard_hole_t *
687 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
689 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
690 return pool_elt_at_index (sb->holes, hole->prev);
694 sack_scoreboard_hole_t *
695 scoreboard_first_hole (sack_scoreboard_t * sb)
697 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
698 return pool_elt_at_index (sb->holes, sb->head);
702 sack_scoreboard_hole_t *
703 scoreboard_last_hole (sack_scoreboard_t * sb)
705 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
706 return pool_elt_at_index (sb->holes, sb->tail);
711 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
713 sack_scoreboard_hole_t *next, *prev;
715 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
717 next = pool_elt_at_index (sb->holes, hole->next);
718 next->prev = hole->prev;
722 sb->tail = hole->prev;
725 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
727 prev = pool_elt_at_index (sb->holes, hole->prev);
728 prev->next = hole->next;
732 sb->head = hole->next;
735 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
736 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
738 /* Poison the entry */
740 clib_memset (hole, 0xfe, sizeof (*hole));
742 pool_put (sb->holes, hole);
745 static sack_scoreboard_hole_t *
746 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
749 sack_scoreboard_hole_t *hole, *next, *prev;
752 pool_get (sb->holes, hole);
753 clib_memset (hole, 0, sizeof (*hole));
757 hole_index = scoreboard_hole_index (sb, hole);
759 prev = scoreboard_get_hole (sb, prev_index);
762 hole->prev = prev_index;
763 hole->next = prev->next;
765 if ((next = scoreboard_next_hole (sb, hole)))
766 next->prev = hole_index;
768 sb->tail = hole_index;
770 prev->next = hole_index;
774 sb->head = hole_index;
775 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
776 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
783 scoreboard_update_sacked_rxt (sack_scoreboard_t * sb, u32 start, u32 end,
786 if (!has_rxt || seq_geq (start, sb->high_rxt))
790 seq_lt (end, sb->high_rxt) ? (end - start) : (sb->high_rxt - start);
794 scoreboard_update_bytes (sack_scoreboard_t * sb, u32 ack, u32 snd_mss)
796 sack_scoreboard_hole_t *left, *right;
797 u32 sacked = 0, blks = 0, old_sacked;
799 old_sacked = sb->sacked_bytes;
801 sb->last_lost_bytes = 0;
803 sb->sacked_bytes = 0;
805 right = scoreboard_last_hole (sb);
808 sb->sacked_bytes = sb->high_sacked - ack;
812 if (seq_gt (sb->high_sacked, right->end))
814 sacked = sb->high_sacked - right->end;
818 while (sacked < (TCP_DUPACK_THRESHOLD - 1) * snd_mss
819 && blks < TCP_DUPACK_THRESHOLD)
822 sb->lost_bytes += scoreboard_hole_bytes (right);
824 left = scoreboard_prev_hole (sb, right);
827 ASSERT (right->start == ack || sb->is_reneging);
828 sacked += right->start - ack;
833 sacked += right->start - left->end;
838 /* right is first lost */
841 sb->lost_bytes += scoreboard_hole_bytes (right);
842 sb->last_lost_bytes += right->is_lost ? 0 : (right->end - right->start);
844 left = scoreboard_prev_hole (sb, right);
847 ASSERT (right->start == ack || sb->is_reneging);
848 sacked += right->start - ack;
851 sacked += right->start - left->end;
855 sb->sacked_bytes = sacked;
856 sb->last_sacked_bytes = sacked - (old_sacked - sb->last_bytes_delivered);
860 * Figure out the next hole to retransmit
862 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
864 sack_scoreboard_hole_t *
865 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
866 sack_scoreboard_hole_t * start,
867 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
869 sack_scoreboard_hole_t *hole = 0;
871 hole = start ? start : scoreboard_first_hole (sb);
872 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
873 hole = scoreboard_next_hole (sb, hole);
875 /* Nothing, return */
878 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
882 /* Rule (1): if higher than rxt, less than high_sacked and lost */
883 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
885 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
889 /* Rule (2): available unsent data */
892 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
895 /* Rule (3): if hole not lost */
896 else if (seq_lt (hole->start, sb->high_sacked))
898 /* And we didn't already retransmit it */
899 if (seq_leq (hole->end, sb->high_rxt))
901 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
905 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
907 /* Rule (4): if hole beyond high_sacked */
910 ASSERT (seq_geq (hole->start, sb->high_sacked));
913 /* HighRxt MUST NOT be updated */
918 if (hole && seq_lt (sb->high_rxt, hole->start))
919 sb->high_rxt = hole->start;
925 scoreboard_init_rxt (sack_scoreboard_t * sb, u32 snd_una)
927 sack_scoreboard_hole_t *hole;
928 hole = scoreboard_first_hole (sb);
931 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
932 sb->cur_rxt_hole = sb->head;
934 sb->high_rxt = snd_una;
935 sb->rescue_rxt = snd_una - 1;
939 scoreboard_init (sack_scoreboard_t * sb)
941 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
942 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
943 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
947 scoreboard_clear (sack_scoreboard_t * sb)
949 sack_scoreboard_hole_t *hole;
950 while ((hole = scoreboard_first_hole (sb)))
952 scoreboard_remove_hole (sb, hole);
954 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
955 ASSERT (pool_elts (sb->holes) == 0);
956 sb->sacked_bytes = 0;
957 sb->last_sacked_bytes = 0;
958 sb->last_bytes_delivered = 0;
960 sb->last_lost_bytes = 0;
961 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
966 scoreboard_clear_reneging (sack_scoreboard_t * sb, u32 start, u32 end)
968 sack_scoreboard_hole_t *last_hole;
970 clib_warning ("sack reneging");
972 scoreboard_clear (sb);
973 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
975 last_hole->is_lost = 1;
976 sb->tail = scoreboard_hole_index (sb, last_hole);
977 sb->high_sacked = start;
978 scoreboard_init_rxt (sb, start);
981 #endif /* CLIB_MARCH_VARIANT */
984 * Test that scoreboard is sane after recovery
986 * Returns 1 if scoreboard is empty or if first hole beyond
990 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
992 sack_scoreboard_hole_t *hole;
993 hole = scoreboard_first_hole (&tc->sack_sb);
994 return (!hole || (seq_geq (hole->start, tc->snd_una)
995 && seq_lt (hole->end, tc->snd_nxt)));
998 #ifndef CLIB_MARCH_VARIANT
1001 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
1003 sack_scoreboard_hole_t *hole, *next_hole;
1004 sack_scoreboard_t *sb = &tc->sack_sb;
1005 sack_block_t *blk, *rcv_sacks;
1006 u32 blk_index = 0, i, j;
1009 sb->last_sacked_bytes = 0;
1010 sb->last_bytes_delivered = 0;
1013 if (!tcp_opts_sack (&tc->rcv_opts)
1014 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1017 has_rxt = tcp_in_cong_recovery (tc);
1019 /* Remove invalid blocks */
1020 blk = tc->rcv_opts.sacks;
1021 while (blk < vec_end (tc->rcv_opts.sacks))
1023 if (seq_lt (blk->start, blk->end)
1024 && seq_gt (blk->start, tc->snd_una)
1025 && seq_gt (blk->start, ack)
1026 && seq_lt (blk->start, tc->snd_nxt)
1027 && seq_leq (blk->end, tc->snd_nxt))
1032 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
1035 /* Add block for cumulative ack */
1036 if (seq_gt (ack, tc->snd_una))
1038 vec_add2 (tc->rcv_opts.sacks, blk, 1);
1039 blk->start = tc->snd_una;
1043 if (vec_len (tc->rcv_opts.sacks) == 0)
1046 tcp_scoreboard_trace_add (tc, ack);
1048 /* Make sure blocks are ordered */
1049 rcv_sacks = tc->rcv_opts.sacks;
1050 for (i = 0; i < vec_len (rcv_sacks); i++)
1051 for (j = i + 1; j < vec_len (rcv_sacks); j++)
1052 if (seq_lt (rcv_sacks[j].start, rcv_sacks[i].start))
1054 sack_block_t tmp = rcv_sacks[i];
1055 rcv_sacks[i] = rcv_sacks[j];
1059 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1061 /* Handle reneging as a special case */
1062 if (PREDICT_FALSE (sb->is_reneging))
1064 /* No holes, only sacked bytes */
1065 if (seq_leq (tc->snd_nxt, sb->high_sacked))
1067 /* No progress made so return */
1068 if (seq_leq (ack, tc->snd_una))
1071 /* Update sacked bytes delivered and return */
1072 sb->last_bytes_delivered = ack - tc->snd_una;
1073 sb->sacked_bytes -= sb->last_bytes_delivered;
1074 sb->is_reneging = seq_lt (ack, sb->high_sacked);
1078 /* New hole above high sacked. Add it and process normally */
1079 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1080 sb->high_sacked, tc->snd_nxt);
1081 sb->tail = scoreboard_hole_index (sb, hole);
1083 /* Not reneging and no holes. Insert the first that covers all
1084 * outstanding bytes */
1087 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1088 tc->snd_una, tc->snd_nxt);
1089 sb->tail = scoreboard_hole_index (sb, hole);
1091 sb->high_sacked = rcv_sacks[vec_len (rcv_sacks) - 1].end;
1095 /* If we have holes but snd_nxt is beyond the last hole, update
1096 * last hole end or add new hole after high sacked */
1097 hole = scoreboard_last_hole (sb);
1098 if (seq_gt (tc->snd_nxt, hole->end))
1100 if (seq_geq (hole->start, sb->high_sacked))
1102 hole->end = tc->snd_nxt;
1104 /* New hole after high sacked block */
1105 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1107 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1112 /* Keep track of max byte sacked for when the last hole
1114 sb->high_sacked = seq_max (rcv_sacks[vec_len (rcv_sacks) - 1].end,
1118 /* Walk the holes with the SACK blocks */
1119 hole = pool_elt_at_index (sb->holes, sb->head);
1121 if (PREDICT_FALSE (sb->is_reneging))
1122 sb->last_bytes_delivered += hole->start - tc->snd_una;
1124 while (hole && blk_index < vec_len (rcv_sacks))
1126 blk = &rcv_sacks[blk_index];
1127 if (seq_leq (blk->start, hole->start))
1129 /* Block covers hole. Remove hole */
1130 if (seq_geq (blk->end, hole->end))
1132 next_hole = scoreboard_next_hole (sb, hole);
1134 /* If covered by ack, compute delivered bytes */
1135 if (blk->end == ack)
1137 u32 sacked = next_hole ? next_hole->start : sb->high_sacked;
1138 if (PREDICT_FALSE (seq_lt (ack, sacked)))
1140 sb->last_bytes_delivered += ack - hole->end;
1141 sb->is_reneging = 1;
1145 sb->last_bytes_delivered += sacked - hole->end;
1146 sb->is_reneging = 0;
1149 scoreboard_update_sacked_rxt (sb, hole->start, hole->end,
1151 scoreboard_remove_hole (sb, hole);
1154 /* Partial 'head' overlap */
1157 if (seq_gt (blk->end, hole->start))
1159 scoreboard_update_sacked_rxt (sb, hole->start, blk->end,
1161 hole->start = blk->end;
1168 /* Hole must be split */
1169 if (seq_lt (blk->end, hole->end))
1171 u32 hole_index = scoreboard_hole_index (sb, hole);
1172 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1174 /* Pool might've moved */
1175 hole = scoreboard_get_hole (sb, hole_index);
1176 hole->end = blk->start;
1178 scoreboard_update_sacked_rxt (sb, blk->start, blk->end,
1182 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1184 else if (seq_lt (blk->start, hole->end))
1186 scoreboard_update_sacked_rxt (sb, blk->start, hole->end,
1188 hole->end = blk->start;
1190 hole = scoreboard_next_hole (sb, hole);
1194 scoreboard_update_bytes (sb, ack, tc->snd_mss);
1196 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1197 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1198 || sb->sacked_bytes <= tc->snd_nxt - seq_max (tc->snd_una, ack));
1199 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1200 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1201 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1202 || sb->is_reneging || sb->holes[sb->head].start == ack);
1203 ASSERT (sb->last_lost_bytes <= sb->lost_bytes);
1204 ASSERT ((ack - tc->snd_una) + sb->last_sacked_bytes
1205 - sb->last_bytes_delivered >= sb->rxt_sacked);
1206 ASSERT ((ack - tc->snd_una) >= tc->sack_sb.last_bytes_delivered
1207 || (tc->flags & TCP_CONN_FINSNT));
1209 TCP_EVT (TCP_EVT_CC_SCOREBOARD, tc);
1211 #endif /* CLIB_MARCH_VARIANT */
1214 * Try to update snd_wnd based on feedback received from peer.
1216 * If successful, and new window is 'effectively' 0, activate persist
1220 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1222 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1223 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1224 if (seq_lt (tc->snd_wl1, seq)
1225 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1227 tc->snd_wnd = snd_wnd;
1230 TCP_EVT (TCP_EVT_SND_WND, tc);
1232 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1234 /* Set persist timer if not set and we just got 0 wnd */
1235 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1236 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1237 tcp_persist_timer_set (tc);
1241 tcp_persist_timer_reset (tc);
1242 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1245 tcp_update_rto (tc);
1252 * Init loss recovery/fast recovery.
1254 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1255 * updated in @ref tcp_cc_handle_event after fast retransmit
1258 tcp_cc_init_congestion (tcp_connection_t * tc)
1260 tcp_fastrecovery_on (tc);
1261 tc->snd_congestion = tc->snd_nxt;
1262 tc->cwnd_acc_bytes = 0;
1263 tc->snd_rxt_bytes = 0;
1264 tc->rxt_delivered = 0;
1265 tc->prr_delivered = 0;
1266 tc->prr_start = tc->snd_una;
1267 tc->prev_ssthresh = tc->ssthresh;
1268 tc->prev_cwnd = tc->cwnd;
1270 tc->snd_rxt_ts = tcp_tstamp (tc);
1271 tcp_cc_congestion (tc);
1273 /* Post retransmit update cwnd to ssthresh and account for the
1274 * three segments that have left the network and should've been
1275 * buffered at the receiver XXX */
1276 if (!tcp_opts_sack_permitted (&tc->rcv_opts))
1277 tc->cwnd += 3 * tc->snd_mss;
1279 tc->fr_occurences += 1;
1280 TCP_EVT (TCP_EVT_CC_EVT, tc, 4);
1284 tcp_cc_congestion_undo (tcp_connection_t * tc)
1286 tc->cwnd = tc->prev_cwnd;
1287 tc->ssthresh = tc->prev_ssthresh;
1288 tcp_cc_undo_recovery (tc);
1289 ASSERT (tc->rto_boff == 0);
1290 TCP_EVT (TCP_EVT_CC_EVT, tc, 5);
1294 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1296 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1298 && tcp_opts_tstamp (&tc->rcv_opts)
1299 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1303 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1305 return (tcp_cc_is_spurious_timeout_rxt (tc));
1309 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1311 return (tc->sack_sb.lost_bytes
1312 || ((TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
1313 < tc->sack_sb.sacked_bytes));
1317 tcp_should_fastrecover (tcp_connection_t * tc, u8 has_sack)
1321 /* If of of the two conditions lower hold, reset dupacks because
1322 * we're probably after timeout (RFC6582 heuristics).
1323 * If Cumulative ack does not cover more than congestion threshold,
1325 * 1) The following doesn't hold: The congestion window is greater
1326 * than SMSS bytes and the difference between highest_ack
1327 * and prev_highest_ack is at most 4*SMSS bytes
1328 * 2) Echoed timestamp in the last non-dup ack does not equal the
1331 if (seq_leq (tc->snd_una, tc->snd_congestion)
1332 && ((!(tc->cwnd > tc->snd_mss
1333 && tc->bytes_acked <= 4 * tc->snd_mss))
1334 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1336 tc->rcv_dupacks = 0;
1340 return ((tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1341 || tcp_should_fastrecover_sack (tc));
1345 tcp_cc_recover (tcp_connection_t * tc)
1347 sack_scoreboard_hole_t *hole;
1350 ASSERT (tcp_in_cong_recovery (tc));
1352 if (tcp_cc_is_spurious_retransmit (tc))
1354 tcp_cc_congestion_undo (tc);
1358 tcp_connection_tx_pacer_reset (tc, tc->cwnd, 0 /* start bucket */ );
1359 tc->rcv_dupacks = 0;
1361 /* Previous recovery left us congested. Continue sending as part
1362 * of the current recovery event with an updated snd_congestion */
1363 if (tc->sack_sb.sacked_bytes)
1365 tc->snd_congestion = tc->snd_nxt;
1366 tcp_program_retransmit (tc);
1370 tc->rxt_delivered = 0;
1371 tc->snd_rxt_bytes = 0;
1373 tc->prr_delivered = 0;
1375 tc->flags &= ~TCP_CONN_RXT_PENDING;
1377 hole = scoreboard_first_hole (&tc->sack_sb);
1378 if (hole && hole->start == tc->snd_una && hole->end == tc->snd_nxt)
1379 scoreboard_clear (&tc->sack_sb);
1381 if (!tcp_in_recovery (tc) && !is_spurious)
1382 tcp_cc_recovered (tc);
1384 tcp_fastrecovery_off (tc);
1385 tcp_fastrecovery_first_off (tc);
1386 tcp_recovery_off (tc);
1387 TCP_EVT (TCP_EVT_CC_EVT, tc, 3);
1389 ASSERT (tc->rto_boff == 0);
1390 ASSERT (!tcp_in_cong_recovery (tc));
1391 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1396 tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1398 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1400 /* Congestion avoidance */
1401 tcp_cc_rcv_ack (tc, rs);
1403 /* If a cumulative ack, make sure dupacks is 0 */
1404 tc->rcv_dupacks = 0;
1406 /* When dupacks hits the threshold we only enter fast retransmit if
1407 * cumulative ack covers more than snd_congestion. Should snd_una
1408 * wrap this test may fail under otherwise valid circumstances.
1409 * Therefore, proactively update snd_congestion when wrap detected. */
1411 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1412 && seq_gt (tc->snd_congestion, tc->snd_una)))
1413 tc->snd_congestion = tc->snd_una - 1;
1417 * One function to rule them all ... and in the darkness bind them
1420 tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs,
1423 u8 has_sack = tcp_opts_sack_permitted (&tc->rcv_opts);
1426 * If not in recovery, figure out if we should enter
1428 if (!tcp_in_cong_recovery (tc))
1433 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1434 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1436 if (tcp_should_fastrecover (tc, has_sack))
1438 tcp_cc_init_congestion (tc);
1441 scoreboard_init_rxt (&tc->sack_sb, tc->snd_una);
1443 tcp_connection_tx_pacer_reset (tc, tc->cwnd, 0 /* start bucket */ );
1444 tcp_program_retransmit (tc);
1451 * Already in recovery
1455 * Process (re)transmit feedback. Output path uses this to decide how much
1456 * more data to release into the network
1460 if (!tc->bytes_acked && tc->sack_sb.rxt_sacked)
1461 tcp_fastrecovery_first_on (tc);
1463 tc->rxt_delivered += tc->sack_sb.rxt_sacked;
1464 tc->prr_delivered += tc->bytes_acked + tc->sack_sb.last_sacked_bytes
1465 - tc->sack_sb.last_bytes_delivered;
1467 tcp_program_retransmit (tc);
1473 tc->rcv_dupacks += 1;
1474 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1476 tc->rxt_delivered = clib_max (tc->rxt_delivered + tc->bytes_acked,
1479 tc->prr_delivered += clib_min (tc->snd_mss,
1480 tc->snd_nxt - tc->snd_una);
1482 tc->prr_delivered += tc->bytes_acked - clib_min (tc->bytes_acked,
1486 /* If partial ack, assume that the first un-acked segment was lost */
1487 if (tc->bytes_acked || tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1488 tcp_fastrecovery_first_on (tc);
1490 tcp_program_retransmit (tc);
1494 * See if we can exit and stop retransmitting
1496 if (seq_geq (tc->snd_una, tc->snd_congestion))
1498 /* If spurious return, we've already updated everything */
1499 if (tcp_cc_recover (tc))
1501 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1505 /* Treat as congestion avoidance ack */
1506 tcp_cc_rcv_ack (tc, rs);
1511 * Notify cc of the event
1514 if (!tc->bytes_acked)
1516 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1520 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1521 * reset dupacks to 0. Also needed if in congestion recovery */
1522 tc->rcv_dupacks = 0;
1524 if (tcp_in_recovery (tc))
1525 tcp_cc_rcv_ack (tc, rs);
1527 tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs);
1531 * Check if duplicate ack as per RFC5681 Sec. 2
1534 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
1537 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
1538 && seq_gt (tc->snd_nxt, tc->snd_una)
1539 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
1540 && (prev_snd_wnd == tc->snd_wnd));
1544 * Checks if ack is a congestion control event.
1547 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
1548 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
1550 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
1551 * defined to be 'duplicate' as well */
1552 *is_dack = tc->sack_sb.last_sacked_bytes
1553 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
1555 /* If reneging, wait for timer based retransmits */
1556 if (PREDICT_FALSE (tcp_is_lost_fin (tc) || tc->sack_sb.is_reneging))
1559 return (*is_dack || tcp_in_cong_recovery (tc));
1563 * Process incoming ACK
1566 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1567 tcp_header_t * th, u32 * error)
1569 u32 prev_snd_wnd, prev_snd_una;
1570 tcp_rate_sample_t rs = { 0 };
1573 TCP_EVT (TCP_EVT_CC_STAT, tc);
1575 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1576 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1578 /* We've probably entered recovery and the peer still has some
1579 * of the data we've sent. Update snd_nxt and accept the ack */
1580 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1581 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1583 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1587 tc->errors.above_ack_wnd += 1;
1588 *error = TCP_ERROR_ACK_FUTURE;
1589 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 0, vnet_buffer (b)->tcp.ack_number);
1593 /* If old ACK, probably it's an old dupack */
1594 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1596 tc->errors.below_ack_wnd += 1;
1597 *error = TCP_ERROR_ACK_OLD;
1598 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 1, vnet_buffer (b)->tcp.ack_number);
1599 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1600 tcp_cc_handle_event (tc, 0, 1);
1601 /* Don't drop yet */
1608 * Looks okay, process feedback
1611 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1612 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1614 prev_snd_wnd = tc->snd_wnd;
1615 prev_snd_una = tc->snd_una;
1616 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1617 vnet_buffer (b)->tcp.ack_number,
1618 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1619 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1620 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
1621 tcp_validate_txf_size (tc, tc->bytes_acked);
1623 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
1624 tcp_bt_sample_delivery_rate (tc, &rs);
1626 tcp_program_dequeue (wrk, tc);
1628 if (tc->bytes_acked)
1629 tcp_update_rtt (tc, &rs, vnet_buffer (b)->tcp.ack_number);
1631 TCP_EVT (TCP_EVT_ACK_RCVD, tc);
1634 * Check if we have congestion event
1637 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1639 tcp_cc_handle_event (tc, &rs, is_dack);
1640 tc->dupacks_in += is_dack;
1641 if (!tcp_in_cong_recovery (tc))
1643 *error = TCP_ERROR_ACK_OK;
1646 *error = TCP_ERROR_ACK_DUP;
1647 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1653 * Update congestion control (slow start/congestion avoidance)
1655 tcp_cc_update (tc, &rs);
1656 *error = TCP_ERROR_ACK_OK;
1661 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1663 if (!tcp_disconnect_pending (tc))
1665 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1666 tcp_disconnect_pending_on (tc);
1671 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1673 u32 thread_index, *pending_disconnects;
1674 tcp_connection_t *tc;
1677 if (!vec_len (wrk->pending_disconnects))
1680 thread_index = wrk->vm->thread_index;
1681 pending_disconnects = wrk->pending_disconnects;
1682 for (i = 0; i < vec_len (pending_disconnects); i++)
1684 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1685 tcp_disconnect_pending_off (tc);
1686 session_transport_closing_notify (&tc->connection);
1688 _vec_len (wrk->pending_disconnects) = 0;
1692 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1695 /* Reject out-of-order fins */
1696 if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt)
1699 /* Account for the FIN and send ack */
1701 tc->flags |= TCP_CONN_FINRCVD;
1702 tcp_program_ack (tc);
1703 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1704 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1705 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1706 tcp_program_disconnect (wrk, tc);
1707 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
1708 TCP_EVT (TCP_EVT_FIN_RCVD, tc);
1709 *error = TCP_ERROR_FIN_RCVD;
1712 #ifndef CLIB_MARCH_VARIANT
1714 tcp_sack_vector_is_sane (sack_block_t * sacks)
1717 for (i = 1; i < vec_len (sacks); i++)
1719 if (sacks[i - 1].end == sacks[i].start)
1726 * Build SACK list as per RFC2018.
1728 * Makes sure the first block contains the segment that generated the current
1729 * ACK and the following ones are the ones most recently reported in SACK
1732 * @param tc TCP connection for which the SACK list is updated
1733 * @param start Start sequence number of the newest SACK block
1734 * @param end End sequence of the newest SACK block
1737 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1739 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1742 /* If the first segment is ooo add it to the list. Last write might've moved
1743 * rcv_nxt over the first segment. */
1744 if (seq_lt (tc->rcv_nxt, start))
1746 vec_add2 (new_list, block, 1);
1747 block->start = start;
1751 /* Find the blocks still worth keeping. */
1752 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1754 /* Discard if rcv_nxt advanced beyond current block */
1755 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1758 /* Merge or drop if segment overlapped by the new segment */
1759 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1760 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1762 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1763 new_list[0].start = tc->snd_sacks[i].start;
1764 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1765 new_list[0].end = tc->snd_sacks[i].end;
1769 /* Save to new SACK list if we have space. */
1770 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1771 vec_add1 (new_list, tc->snd_sacks[i]);
1774 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1776 /* Replace old vector with new one */
1777 vec_reset_length (tc->snd_sacks);
1778 tc->snd_sacks_fl = tc->snd_sacks;
1779 tc->snd_sacks = new_list;
1781 /* Segments should not 'touch' */
1782 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1786 tcp_sack_list_bytes (tcp_connection_t * tc)
1789 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1790 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1793 #endif /* CLIB_MARCH_VARIANT */
1795 /** Enqueue data for delivery to application */
1797 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1800 int written, error = TCP_ERROR_ENQUEUED;
1802 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1804 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1805 1 /* queue event */ , 1);
1806 tc->bytes_in += written;
1808 TCP_EVT (TCP_EVT_INPUT, tc, 0, data_len, written);
1810 /* Update rcv_nxt */
1811 if (PREDICT_TRUE (written == data_len))
1813 tc->rcv_nxt += written;
1815 /* If more data written than expected, account for out-of-order bytes. */
1816 else if (written > data_len)
1818 tc->rcv_nxt += written;
1819 TCP_EVT (TCP_EVT_CC_INPUT, tc, data_len, written);
1821 else if (written > 0)
1823 /* We've written something but FIFO is probably full now */
1824 tc->rcv_nxt += written;
1825 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1829 return TCP_ERROR_FIFO_FULL;
1832 /* Update SACK list if need be */
1833 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1835 /* Remove SACK blocks that have been delivered */
1836 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1842 /** Enqueue out-of-order data */
1844 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1850 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1853 /* Enqueue out-of-order data with relative offset */
1854 rv = session_enqueue_stream_connection (&tc->connection, b,
1855 vnet_buffer (b)->tcp.seq_number -
1856 tc->rcv_nxt, 0 /* queue event */ ,
1859 /* Nothing written */
1862 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, 0);
1863 return TCP_ERROR_FIFO_FULL;
1866 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1867 tc->bytes_in += data_len;
1869 /* Update SACK list if in use */
1870 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1872 ooo_segment_t *newest;
1875 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1877 /* Get the newest segment from the fifo */
1878 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1881 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1882 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1883 start = tc->rcv_nxt + offset;
1884 end = start + ooo_segment_length (s0->rx_fifo, newest);
1885 tcp_update_sack_list (tc, start, end);
1886 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1887 TCP_EVT (TCP_EVT_CC_SACKS, tc);
1891 return TCP_ERROR_ENQUEUED_OOO;
1895 * Check if ACK could be delayed. If ack can be delayed, it should return
1896 * true for a full frame. If we're always acking return 0.
1899 tcp_can_delack (tcp_connection_t * tc)
1901 /* Send ack if ... */
1903 /* just sent a rcv wnd 0
1904 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1905 /* constrained to send ack */
1906 || (tc->flags & TCP_CONN_SNDACK) != 0
1907 /* we're almost out of tx wnd */
1908 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1915 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1917 u32 discard, first = b->current_length;
1918 vlib_main_t *vm = vlib_get_main ();
1920 /* Handle multi-buffer segments */
1921 if (n_bytes_to_drop > b->current_length)
1923 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1927 discard = clib_min (n_bytes_to_drop, b->current_length);
1928 vlib_buffer_advance (b, discard);
1929 b = vlib_get_buffer (vm, b->next_buffer);
1930 n_bytes_to_drop -= discard;
1932 while (n_bytes_to_drop);
1933 if (n_bytes_to_drop > first)
1934 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1937 vlib_buffer_advance (b, n_bytes_to_drop);
1938 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1943 * Receive buffer for connection and handle acks
1945 * It handles both in order or out-of-order data.
1948 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1951 u32 error, n_bytes_to_drop, n_data_bytes;
1953 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1954 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1955 ASSERT (n_data_bytes);
1956 tc->data_segs_in += 1;
1958 /* Handle out-of-order data */
1959 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1961 /* Old sequence numbers allowed through because they overlapped
1963 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1965 /* Completely in the past (possible retransmit). Ack
1966 * retransmissions since we may not have any data to send */
1967 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1969 tcp_program_ack (tc);
1970 error = TCP_ERROR_SEGMENT_OLD;
1974 /* Chop off the bytes in the past and see if what is left
1975 * can be enqueued in order */
1976 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1977 n_data_bytes -= n_bytes_to_drop;
1978 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1979 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1981 error = TCP_ERROR_SEGMENT_OLD;
1987 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1988 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1989 tcp_program_dupack (tc);
1990 TCP_EVT (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1991 tc->errors.above_data_wnd += seq_gt (vnet_buffer (b)->tcp.seq_end,
1992 tc->rcv_las + tc->rcv_wnd);
1998 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1999 * segments can be enqueued after fifo tail offset changes. */
2000 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
2001 if (tcp_can_delack (tc))
2003 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
2004 tcp_timer_set (tc, TCP_TIMER_DELACK, tcp_cfg.delack_time);
2008 tcp_program_ack (tc);
2016 tcp_header_t tcp_header;
2017 tcp_connection_t tcp_connection;
2021 format_tcp_rx_trace (u8 * s, va_list * args)
2023 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2024 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2025 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2026 u32 indent = format_get_indent (s);
2028 s = format (s, "%U\n%U%U",
2029 format_tcp_header, &t->tcp_header, 128,
2030 format_white_space, indent,
2031 format_tcp_connection, &t->tcp_connection, 1);
2037 format_tcp_rx_trace_short (u8 * s, va_list * args)
2039 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2040 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2041 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2043 s = format (s, "%d -> %d (%U)",
2044 clib_net_to_host_u16 (t->tcp_header.dst_port),
2045 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2046 t->tcp_connection.state);
2052 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2053 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2057 clib_memcpy_fast (&t0->tcp_connection, tc0,
2058 sizeof (t0->tcp_connection));
2062 th0 = tcp_buffer_hdr (b0);
2064 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2068 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2069 vlib_frame_t * frame, u8 is_ip4)
2073 n_left = frame->n_vectors;
2074 from = vlib_frame_vector_args (frame);
2078 tcp_connection_t *tc0;
2085 b0 = vlib_get_buffer (vm, bi0);
2087 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2089 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2090 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2092 th0 = tcp_buffer_hdr (b0);
2093 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2102 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2103 u8 is_ip4, u32 evt, u32 val)
2106 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2108 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2111 #define tcp_maybe_inc_counter(node_id, err, count) \
2113 if (next0 != tcp_next_drop (is_ip4)) \
2114 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2115 tcp6_##node_id##_node.index, is_ip4, err, \
2118 #define tcp_inc_counter(node_id, err, count) \
2119 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2120 tcp6_##node_id##_node.index, is_ip4, \
2122 #define tcp_maybe_inc_err_counter(cnts, err) \
2124 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2126 #define tcp_inc_err_counter(cnts, err, val) \
2130 #define tcp_store_err_counters(node_id, cnts) \
2133 for (i = 0; i < TCP_N_ERROR; i++) \
2135 tcp_inc_counter(node_id, i, cnts[i]); \
2140 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2141 vlib_frame_t * frame, int is_ip4)
2143 u32 thread_index = vm->thread_index, errors = 0;
2144 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2145 u32 n_left_from, *from, *first_buffer;
2146 u16 err_counters[TCP_N_ERROR] = { 0 };
2148 if (node->flags & VLIB_NODE_FLAG_TRACE)
2149 tcp_established_trace_frame (vm, node, frame, is_ip4);
2151 first_buffer = from = vlib_frame_vector_args (frame);
2152 n_left_from = frame->n_vectors;
2154 while (n_left_from > 0)
2156 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2159 tcp_connection_t *tc0;
2161 if (n_left_from > 1)
2164 pb = vlib_get_buffer (vm, from[1]);
2165 vlib_prefetch_buffer_header (pb, LOAD);
2166 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2173 b0 = vlib_get_buffer (vm, bi0);
2174 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2177 if (PREDICT_FALSE (tc0 == 0))
2179 error0 = TCP_ERROR_INVALID_CONNECTION;
2183 th0 = tcp_buffer_hdr (b0);
2185 /* TODO header prediction fast path */
2187 /* 1-4: check SEQ, RST, SYN */
2188 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2190 TCP_EVT (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2194 /* 5: check the ACK field */
2195 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2198 /* 6: check the URG bit TODO */
2200 /* 7: process the segment text */
2201 if (vnet_buffer (b0)->tcp.data_len)
2202 error0 = tcp_segment_rcv (wrk, tc0, b0);
2204 /* 8: check the FIN bit */
2205 if (PREDICT_FALSE (tcp_is_fin (th0)))
2206 tcp_rcv_fin (wrk, tc0, b0, &error0);
2209 tcp_inc_err_counter (err_counters, error0, 1);
2212 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2214 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2215 tcp_store_err_counters (established, err_counters);
2216 tcp_handle_postponed_dequeues (wrk);
2217 tcp_handle_disconnects (wrk);
2218 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2220 return frame->n_vectors;
2223 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2224 vlib_node_runtime_t * node,
2225 vlib_frame_t * from_frame)
2227 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2230 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2231 vlib_node_runtime_t * node,
2232 vlib_frame_t * from_frame)
2234 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2238 VLIB_REGISTER_NODE (tcp4_established_node) =
2240 .name = "tcp4-established",
2241 /* Takes a vector of packets. */
2242 .vector_size = sizeof (u32),
2243 .n_errors = TCP_N_ERROR,
2244 .error_strings = tcp_error_strings,
2245 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2248 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2249 foreach_tcp_state_next
2252 .format_trace = format_tcp_rx_trace_short,
2257 VLIB_REGISTER_NODE (tcp6_established_node) =
2259 .name = "tcp6-established",
2260 /* Takes a vector of packets. */
2261 .vector_size = sizeof (u32),
2262 .n_errors = TCP_N_ERROR,
2263 .error_strings = tcp_error_strings,
2264 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2267 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2268 foreach_tcp_state_next
2271 .format_trace = format_tcp_rx_trace_short,
2277 tcp_lookup_is_valid (tcp_connection_t * tc, vlib_buffer_t * b,
2280 transport_connection_t *tmp = 0;
2287 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2290 u8 is_ip_valid = 0, val_l, val_r;
2292 if (tc->connection.is_ip4)
2294 ip4_header_t *ip4_hdr = (ip4_header_t *) vlib_buffer_get_current (b);
2296 val_l = !ip4_address_compare (&ip4_hdr->dst_address,
2297 &tc->connection.lcl_ip.ip4);
2298 val_l = val_l || ip_is_zero (&tc->connection.lcl_ip, 1);
2299 val_r = !ip4_address_compare (&ip4_hdr->src_address,
2300 &tc->connection.rmt_ip.ip4);
2301 val_r = val_r || tc->state == TCP_STATE_LISTEN;
2302 is_ip_valid = val_l && val_r;
2306 ip6_header_t *ip6_hdr = (ip6_header_t *) vlib_buffer_get_current (b);
2308 val_l = !ip6_address_compare (&ip6_hdr->dst_address,
2309 &tc->connection.lcl_ip.ip6);
2310 val_l = val_l || ip_is_zero (&tc->connection.lcl_ip, 0);
2311 val_r = !ip6_address_compare (&ip6_hdr->src_address,
2312 &tc->connection.rmt_ip.ip6);
2313 val_r = val_r || tc->state == TCP_STATE_LISTEN;
2314 is_ip_valid = val_l && val_r;
2317 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2318 && (tc->state == TCP_STATE_LISTEN
2319 || tc->c_rmt_port == hdr->src_port) && is_ip_valid);
2323 handle = session_lookup_half_open_handle (&tc->connection);
2324 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2325 tc->c_proto, tc->c_is_ip4);
2329 if (tmp->lcl_port == hdr->dst_port
2330 && tmp->rmt_port == hdr->src_port)
2332 TCP_DBG ("half-open is valid!");
2341 * Lookup transport connection
2343 static tcp_connection_t *
2344 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2348 transport_connection_t *tconn;
2349 tcp_connection_t *tc;
2354 ip4 = vlib_buffer_get_current (b);
2355 tcp = ip4_next_header (ip4);
2356 tconn = session_lookup_connection_wt4 (fib_index,
2361 TRANSPORT_PROTO_TCP,
2362 thread_index, &is_filtered);
2363 tc = tcp_get_connection_from_transport (tconn);
2364 ASSERT (tcp_lookup_is_valid (tc, b, tcp));
2369 ip6 = vlib_buffer_get_current (b);
2370 tcp = ip6_next_header (ip6);
2371 tconn = session_lookup_connection_wt6 (fib_index,
2376 TRANSPORT_PROTO_TCP,
2377 thread_index, &is_filtered);
2378 tc = tcp_get_connection_from_transport (tconn);
2379 ASSERT (tcp_lookup_is_valid (tc, b, tcp));
2385 tcp_check_tx_offload (tcp_connection_t * tc, int is_ipv4)
2387 vnet_main_t *vnm = vnet_get_main ();
2388 const dpo_id_t *dpo;
2389 const load_balance_t *lb;
2390 vnet_hw_interface_t *hw_if;
2391 u32 sw_if_idx, lb_idx;
2395 ip4_address_t *dst_addr = &(tc->c_rmt_ip.ip4);
2396 lb_idx = ip4_fib_forwarding_lookup (tc->c_fib_index, dst_addr);
2400 ip6_address_t *dst_addr = &(tc->c_rmt_ip.ip6);
2401 lb_idx = ip6_fib_table_fwding_lookup (tc->c_fib_index, dst_addr);
2404 lb = load_balance_get (lb_idx);
2405 dpo = load_balance_get_bucket_i (lb, 0);
2407 sw_if_idx = dpo->dpoi_index;
2408 hw_if = vnet_get_sup_hw_interface (vnm, sw_if_idx);
2410 if (hw_if->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO)
2411 tc->cfg_flags |= TCP_CFG_F_TSO;
2415 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2416 vlib_frame_t * from_frame, int is_ip4)
2418 u32 n_left_from, *from, *first_buffer, errors = 0;
2419 u32 my_thread_index = vm->thread_index;
2420 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2422 from = first_buffer = vlib_frame_vector_args (from_frame);
2423 n_left_from = from_frame->n_vectors;
2425 while (n_left_from > 0)
2427 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2428 tcp_connection_t *tc0, *new_tc0;
2429 tcp_header_t *tcp0 = 0;
2437 b0 = vlib_get_buffer (vm, bi0);
2439 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2440 if (PREDICT_FALSE (tc0 == 0))
2442 error0 = TCP_ERROR_INVALID_CONNECTION;
2446 /* Half-open completed recently but the connection was't removed
2447 * yet by the owning thread */
2448 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2450 /* Make sure the connection actually exists */
2451 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2452 my_thread_index, is_ip4));
2453 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2457 ack0 = vnet_buffer (b0)->tcp.ack_number;
2458 seq0 = vnet_buffer (b0)->tcp.seq_number;
2459 tcp0 = tcp_buffer_hdr (b0);
2461 /* Crude check to see if the connection handle does not match
2462 * the packet. Probably connection just switched to established */
2463 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2464 || tcp0->src_port != tc0->c_rmt_port))
2466 error0 = TCP_ERROR_INVALID_CONNECTION;
2470 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2471 && !tcp_syn (tcp0)))
2473 error0 = TCP_ERROR_SEGMENT_INVALID;
2477 /* SYNs consume sequence numbers */
2478 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2481 * 1. check the ACK bit
2485 * If the ACK bit is set
2486 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2487 * the RST bit is set, if so drop the segment and return)
2488 * <SEQ=SEG.ACK><CTL=RST>
2489 * and discard the segment. Return.
2490 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2494 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2496 if (!tcp_rst (tcp0))
2497 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2498 error0 = TCP_ERROR_RCV_WND;
2502 /* Make sure ACK is valid */
2503 if (seq_gt (tc0->snd_una, ack0))
2505 error0 = TCP_ERROR_ACK_INVALID;
2511 * 2. check the RST bit
2516 /* If ACK is acceptable, signal client that peer is not
2517 * willing to accept connection and drop connection*/
2519 tcp_connection_reset (tc0);
2520 error0 = TCP_ERROR_RST_RCVD;
2525 * 3. check the security and precedence (skipped)
2529 * 4. check the SYN bit
2532 /* No SYN flag. Drop. */
2533 if (!tcp_syn (tcp0))
2535 error0 = TCP_ERROR_SEGMENT_INVALID;
2540 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2542 error0 = TCP_ERROR_OPTIONS;
2546 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2547 * current thread pool. */
2548 new_tc0 = tcp_connection_alloc_w_base (my_thread_index, tc0);
2549 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2550 new_tc0->irs = seq0;
2551 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2552 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2554 /* If this is not the owning thread, wait for syn retransmit to
2555 * expire and cleanup then */
2556 if (tcp_half_open_connection_cleanup (tc0))
2557 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2559 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2561 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2562 new_tc0->tsval_recent_age = tcp_time_now ();
2565 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2566 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2568 new_tc0->rcv_wscale = 0;
2570 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2571 << new_tc0->snd_wscale;
2572 new_tc0->snd_wl1 = seq0;
2573 new_tc0->snd_wl2 = ack0;
2575 tcp_connection_init_vars (new_tc0);
2577 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2578 if (PREDICT_TRUE (tcp_ack (tcp0)))
2580 /* Our SYN is ACKed: we have iss < ack = snd_una */
2582 /* TODO Dequeue acknowledged segments if we support Fast Open */
2583 new_tc0->snd_una = ack0;
2584 new_tc0->state = TCP_STATE_ESTABLISHED;
2586 /* Make sure las is initialized for the wnd computation */
2587 new_tc0->rcv_las = new_tc0->rcv_nxt;
2589 /* Notify app that we have connection. If session layer can't
2590 * allocate session send reset */
2591 if (session_stream_connect_notify (&new_tc0->connection, 0))
2593 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2594 tcp_connection_cleanup (new_tc0);
2595 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2599 new_tc0->tx_fifo_size =
2600 transport_tx_fifo_size (&new_tc0->connection);
2601 /* Update rtt with the syn-ack sample */
2602 tcp_estimate_initial_rtt (new_tc0);
2603 TCP_EVT (TCP_EVT_SYNACK_RCVD, new_tc0);
2604 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2606 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2609 new_tc0->state = TCP_STATE_SYN_RCVD;
2611 /* Notify app that we have connection */
2612 if (session_stream_connect_notify (&new_tc0->connection, 0))
2614 tcp_connection_cleanup (new_tc0);
2615 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2616 TCP_EVT (TCP_EVT_RST_SENT, tc0);
2617 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2621 new_tc0->tx_fifo_size =
2622 transport_tx_fifo_size (&new_tc0->connection);
2623 new_tc0->rtt_ts = 0;
2624 tcp_init_snd_vars (new_tc0);
2625 tcp_send_synack (new_tc0);
2626 error0 = TCP_ERROR_SYNS_RCVD;
2630 if (!(new_tc0->cfg_flags & TCP_CFG_F_NO_TSO))
2631 tcp_check_tx_offload (new_tc0, is_ip4);
2633 /* Read data, if any */
2634 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2636 clib_warning ("rcvd data in syn-sent");
2637 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2638 if (error0 == TCP_ERROR_ACK_OK)
2639 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2643 /* Send ack now instead of programming it because connection was
2644 * just established and it's not optional. */
2645 tcp_send_ack (new_tc0);
2650 tcp_inc_counter (syn_sent, error0, 1);
2651 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2653 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2654 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2655 clib_memcpy_fast (&t0->tcp_connection, tc0,
2656 sizeof (t0->tcp_connection));
2660 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2662 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2663 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2665 return from_frame->n_vectors;
2668 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2669 vlib_node_runtime_t * node,
2670 vlib_frame_t * from_frame)
2672 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2675 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2676 vlib_node_runtime_t * node,
2677 vlib_frame_t * from_frame)
2679 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2683 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2685 .name = "tcp4-syn-sent",
2686 /* Takes a vector of packets. */
2687 .vector_size = sizeof (u32),
2688 .n_errors = TCP_N_ERROR,
2689 .error_strings = tcp_error_strings,
2690 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2693 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2694 foreach_tcp_state_next
2697 .format_trace = format_tcp_rx_trace_short,
2702 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2704 .name = "tcp6-syn-sent",
2705 /* Takes a vector of packets. */
2706 .vector_size = sizeof (u32),
2707 .n_errors = TCP_N_ERROR,
2708 .error_strings = tcp_error_strings,
2709 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2712 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2713 foreach_tcp_state_next
2716 .format_trace = format_tcp_rx_trace_short,
2721 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2722 * as per RFC793 p. 64
2725 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2726 vlib_frame_t * from_frame, int is_ip4)
2728 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2729 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2730 u32 n_left_from, *from, max_dequeue;
2732 from = first_buffer = vlib_frame_vector_args (from_frame);
2733 n_left_from = from_frame->n_vectors;
2735 while (n_left_from > 0)
2737 u32 bi0, error0 = TCP_ERROR_NONE;
2738 tcp_header_t *tcp0 = 0;
2739 tcp_connection_t *tc0;
2747 b0 = vlib_get_buffer (vm, bi0);
2748 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2750 if (PREDICT_FALSE (tc0 == 0))
2752 error0 = TCP_ERROR_INVALID_CONNECTION;
2756 tcp0 = tcp_buffer_hdr (b0);
2757 is_fin0 = tcp_is_fin (tcp0);
2761 if (!(tc0->connection.flags & TRANSPORT_CONNECTION_F_NO_LOOKUP))
2763 tcp_connection_t *tmp;
2764 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2766 if (tmp->state != tc0->state)
2768 if (tc0->state != TCP_STATE_CLOSED)
2769 clib_warning ("state changed");
2776 * Special treatment for CLOSED
2778 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2780 error0 = TCP_ERROR_CONNECTION_CLOSED;
2785 * For all other states (except LISTEN)
2788 /* 1-4: check SEQ, RST, SYN */
2789 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2792 /* 5: check the ACK field */
2795 case TCP_STATE_SYN_RCVD:
2797 /* Make sure the segment is exactly right */
2798 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2800 tcp_connection_reset (tc0);
2801 error0 = TCP_ERROR_SEGMENT_INVALID;
2806 * If the segment acknowledgment is not acceptable, form a
2808 * <SEQ=SEG.ACK><CTL=RST>
2811 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2813 tcp_connection_reset (tc0);
2817 /* Update rtt and rto */
2818 tcp_estimate_initial_rtt (tc0);
2819 tcp_connection_tx_pacer_update (tc0);
2821 /* Switch state to ESTABLISHED */
2822 tc0->state = TCP_STATE_ESTABLISHED;
2823 TCP_EVT (TCP_EVT_STATE_CHANGE, tc0);
2825 if (!(tc0->cfg_flags & TCP_CFG_F_NO_TSO))
2826 tcp_check_tx_offload (tc0, is_ip4);
2828 /* Initialize session variables */
2829 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2830 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2831 << tc0->rcv_opts.wscale;
2832 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2833 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2835 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2836 tcp_retransmit_timer_reset (tc0);
2837 if (session_stream_accept_notify (&tc0->connection))
2839 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2840 tcp_connection_reset (tc0);
2843 error0 = TCP_ERROR_ACK_OK;
2845 case TCP_STATE_ESTABLISHED:
2846 /* We can get packets in established state here because they
2847 * were enqueued before state change */
2848 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2852 case TCP_STATE_FIN_WAIT_1:
2853 /* In addition to the processing for the ESTABLISHED state, if
2854 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2855 * continue processing in that state. */
2856 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2859 /* Still have to send the FIN */
2860 if (tc0->flags & TCP_CONN_FINPNDG)
2862 /* TX fifo finally drained */
2863 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2864 if (max_dequeue <= tc0->burst_acked)
2866 /* If a fin was received and data was acked extend wait */
2867 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
2868 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2869 tcp_cfg.closewait_time);
2871 /* If FIN is ACKed */
2872 else if (tc0->snd_una == tc0->snd_nxt)
2874 /* Stop all retransmit timers because we have nothing more
2876 tcp_connection_timers_reset (tc0);
2878 /* We already have a FIN but didn't transition to CLOSING
2879 * because of outstanding tx data. Close the connection. */
2880 if (tc0->flags & TCP_CONN_FINRCVD)
2882 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2883 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE,
2884 tcp_cfg.cleanup_time);
2885 session_transport_closed_notify (&tc0->connection);
2889 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2890 /* Enable waitclose because we're willing to wait for peer's
2891 * FIN but not indefinitely. */
2892 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait2_time);
2894 /* Don't try to deq the FIN acked */
2895 if (tc0->burst_acked > 1)
2896 session_tx_fifo_dequeue_drop (&tc0->connection,
2897 tc0->burst_acked - 1);
2898 tc0->burst_acked = 0;
2901 case TCP_STATE_FIN_WAIT_2:
2902 /* In addition to the processing for the ESTABLISHED state, if
2903 * the retransmission queue is empty, the user's CLOSE can be
2904 * acknowledged ("ok") but do not delete the TCB. */
2905 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2907 tc0->burst_acked = 0;
2909 case TCP_STATE_CLOSE_WAIT:
2910 /* Do the same processing as for the ESTABLISHED state. */
2911 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2914 if (!(tc0->flags & TCP_CONN_FINPNDG))
2917 /* Still have outstanding tx data */
2918 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2919 if (max_dequeue > tc0->burst_acked)
2923 tcp_connection_timers_reset (tc0);
2924 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2925 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2927 case TCP_STATE_CLOSING:
2928 /* In addition to the processing for the ESTABLISHED state, if
2929 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2930 * otherwise ignore the segment. */
2931 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2934 if (tc0->snd_una != tc0->snd_nxt)
2937 tcp_connection_timers_reset (tc0);
2938 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2939 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2940 session_transport_closed_notify (&tc0->connection);
2944 case TCP_STATE_LAST_ACK:
2945 /* The only thing that [should] arrive in this state is an
2946 * acknowledgment of our FIN. If our FIN is now acknowledged,
2947 * delete the TCB, enter the CLOSED state, and return. */
2949 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2952 /* Apparently our ACK for the peer's FIN was lost */
2953 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2959 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2960 session_transport_closed_notify (&tc0->connection);
2962 /* Don't free the connection from the data path since
2963 * we can't ensure that we have no packets already enqueued
2964 * to output. Rely instead on the waitclose timer */
2965 tcp_connection_timers_reset (tc0);
2966 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
2971 case TCP_STATE_TIME_WAIT:
2972 /* The only thing that can arrive in this state is a
2973 * retransmission of the remote FIN. Acknowledge it, and restart
2974 * the 2 MSL timeout. */
2976 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2982 tcp_program_ack (tc0);
2983 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2991 /* 6: check the URG bit TODO */
2993 /* 7: process the segment text */
2996 case TCP_STATE_ESTABLISHED:
2997 case TCP_STATE_FIN_WAIT_1:
2998 case TCP_STATE_FIN_WAIT_2:
2999 if (vnet_buffer (b0)->tcp.data_len)
3000 error0 = tcp_segment_rcv (wrk, tc0, b0);
3002 case TCP_STATE_CLOSE_WAIT:
3003 case TCP_STATE_CLOSING:
3004 case TCP_STATE_LAST_ACK:
3005 case TCP_STATE_TIME_WAIT:
3006 /* This should not occur, since a FIN has been received from the
3007 * remote side. Ignore the segment text. */
3011 /* 8: check the FIN bit */
3015 TCP_EVT (TCP_EVT_FIN_RCVD, tc0);
3019 case TCP_STATE_ESTABLISHED:
3020 /* Account for the FIN and send ack */
3022 tcp_program_ack (tc0);
3023 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
3024 tcp_program_disconnect (wrk, tc0);
3025 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
3027 case TCP_STATE_SYN_RCVD:
3028 /* Send FIN-ACK, enter LAST-ACK and because the app was not
3029 * notified yet, set a cleanup timer instead of relying on
3030 * disconnect notify and the implicit close call. */
3031 tcp_connection_timers_reset (tc0);
3034 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
3035 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
3037 case TCP_STATE_CLOSE_WAIT:
3038 case TCP_STATE_CLOSING:
3039 case TCP_STATE_LAST_ACK:
3042 case TCP_STATE_FIN_WAIT_1:
3045 if (tc0->flags & TCP_CONN_FINPNDG)
3047 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
3048 * sending it. Since we already received a fin, do not wait
3050 tc0->flags |= TCP_CONN_FINRCVD;
3051 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
3052 tcp_cfg.closewait_time);
3056 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
3057 tcp_program_ack (tc0);
3058 /* Wait for ACK for our FIN but not forever */
3059 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
3060 tcp_cfg.closing_time);
3063 case TCP_STATE_FIN_WAIT_2:
3064 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
3066 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
3067 tcp_connection_timers_reset (tc0);
3068 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3069 tcp_program_ack (tc0);
3070 session_transport_closed_notify (&tc0->connection);
3072 case TCP_STATE_TIME_WAIT:
3073 /* Remain in the TIME-WAIT state. Restart the time-wait
3076 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3079 error0 = TCP_ERROR_FIN_RCVD;
3083 tcp_inc_counter (rcv_process, error0, 1);
3084 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3086 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3087 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3091 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
3093 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3094 tcp_handle_postponed_dequeues (wrk);
3095 tcp_handle_disconnects (wrk);
3096 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3098 return from_frame->n_vectors;
3101 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
3102 vlib_node_runtime_t * node,
3103 vlib_frame_t * from_frame)
3105 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3108 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
3109 vlib_node_runtime_t * node,
3110 vlib_frame_t * from_frame)
3112 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3116 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3118 .name = "tcp4-rcv-process",
3119 /* Takes a vector of packets. */
3120 .vector_size = sizeof (u32),
3121 .n_errors = TCP_N_ERROR,
3122 .error_strings = tcp_error_strings,
3123 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3126 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3127 foreach_tcp_state_next
3130 .format_trace = format_tcp_rx_trace_short,
3135 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3137 .name = "tcp6-rcv-process",
3138 /* Takes a vector of packets. */
3139 .vector_size = sizeof (u32),
3140 .n_errors = TCP_N_ERROR,
3141 .error_strings = tcp_error_strings,
3142 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3145 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3146 foreach_tcp_state_next
3149 .format_trace = format_tcp_rx_trace_short,
3154 * LISTEN state processing as per RFC 793 p. 65
3157 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3158 vlib_frame_t * from_frame, int is_ip4)
3160 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3161 u32 my_thread_index = vm->thread_index;
3163 from = first_buffer = vlib_frame_vector_args (from_frame);
3164 n_left_from = from_frame->n_vectors;
3166 while (n_left_from > 0)
3171 tcp_header_t *th0 = 0;
3172 tcp_connection_t *lc0;
3175 tcp_connection_t *child0;
3176 u32 error0 = TCP_ERROR_NONE;
3182 b0 = vlib_get_buffer (vm, bi0);
3183 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3187 ip40 = vlib_buffer_get_current (b0);
3188 th0 = ip4_next_header (ip40);
3192 ip60 = vlib_buffer_get_current (b0);
3193 th0 = ip6_next_header (ip60);
3196 /* Create child session. For syn-flood protection use filter */
3198 /* 1. first check for an RST: handled in dispatch */
3199 /* if (tcp_rst (th0))
3203 /* 2. second check for an ACK: handled in dispatch */
3204 /* if (tcp_ack (th0))
3206 tcp_send_reset (b0, is_ip4);
3211 /* 3. check for a SYN (did that already) */
3213 /* Make sure connection wasn't just created */
3214 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3216 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3218 error0 = TCP_ERROR_CREATE_EXISTS;
3222 /* Create child session and send SYN-ACK */
3223 child0 = tcp_connection_alloc (my_thread_index);
3224 child0->c_lcl_port = th0->dst_port;
3225 child0->c_rmt_port = th0->src_port;
3226 child0->c_is_ip4 = is_ip4;
3227 child0->state = TCP_STATE_SYN_RCVD;
3228 child0->c_fib_index = lc0->c_fib_index;
3229 child0->cc_algo = lc0->cc_algo;
3233 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3234 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3238 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3239 sizeof (ip6_address_t));
3240 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3241 sizeof (ip6_address_t));
3244 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3246 error0 = TCP_ERROR_OPTIONS;
3247 tcp_connection_free (child0);
3251 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3252 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3253 child0->rcv_las = child0->rcv_nxt;
3254 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3256 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3257 * segments are used to initialize PAWS. */
3258 if (tcp_opts_tstamp (&child0->rcv_opts))
3260 child0->tsval_recent = child0->rcv_opts.tsval;
3261 child0->tsval_recent_age = tcp_time_now ();
3264 if (tcp_opts_wscale (&child0->rcv_opts))
3265 child0->snd_wscale = child0->rcv_opts.wscale;
3267 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3268 << child0->snd_wscale;
3269 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3270 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3272 tcp_connection_init_vars (child0);
3273 child0->rto = TCP_RTO_MIN;
3275 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3276 lc0->c_thread_index, 0 /* notify */ ))
3278 tcp_connection_cleanup (child0);
3279 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3283 TCP_EVT (TCP_EVT_SYN_RCVD, child0, 1);
3284 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3285 tcp_send_synack (child0);
3289 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3291 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3292 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3293 clib_memcpy_fast (&t0->tcp_connection, lc0,
3294 sizeof (t0->tcp_connection));
3297 n_syns += (error0 == TCP_ERROR_NONE);
3300 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3301 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3303 return from_frame->n_vectors;
3306 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3307 vlib_frame_t * from_frame)
3309 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3312 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3313 vlib_frame_t * from_frame)
3315 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3319 VLIB_REGISTER_NODE (tcp4_listen_node) =
3321 .name = "tcp4-listen",
3322 /* Takes a vector of packets. */
3323 .vector_size = sizeof (u32),
3324 .n_errors = TCP_N_ERROR,
3325 .error_strings = tcp_error_strings,
3326 .n_next_nodes = TCP_LISTEN_N_NEXT,
3329 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3330 foreach_tcp_state_next
3333 .format_trace = format_tcp_rx_trace_short,
3338 VLIB_REGISTER_NODE (tcp6_listen_node) =
3340 .name = "tcp6-listen",
3341 /* Takes a vector of packets. */
3342 .vector_size = sizeof (u32),
3343 .n_errors = TCP_N_ERROR,
3344 .error_strings = tcp_error_strings,
3345 .n_next_nodes = TCP_LISTEN_N_NEXT,
3348 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3349 foreach_tcp_state_next
3352 .format_trace = format_tcp_rx_trace_short,
3356 typedef enum _tcp_input_next
3358 TCP_INPUT_NEXT_DROP,
3359 TCP_INPUT_NEXT_LISTEN,
3360 TCP_INPUT_NEXT_RCV_PROCESS,
3361 TCP_INPUT_NEXT_SYN_SENT,
3362 TCP_INPUT_NEXT_ESTABLISHED,
3363 TCP_INPUT_NEXT_RESET,
3364 TCP_INPUT_NEXT_PUNT,
3368 #define foreach_tcp4_input_next \
3369 _ (DROP, "ip4-drop") \
3370 _ (LISTEN, "tcp4-listen") \
3371 _ (RCV_PROCESS, "tcp4-rcv-process") \
3372 _ (SYN_SENT, "tcp4-syn-sent") \
3373 _ (ESTABLISHED, "tcp4-established") \
3374 _ (RESET, "tcp4-reset") \
3375 _ (PUNT, "ip4-punt")
3377 #define foreach_tcp6_input_next \
3378 _ (DROP, "ip6-drop") \
3379 _ (LISTEN, "tcp6-listen") \
3380 _ (RCV_PROCESS, "tcp6-rcv-process") \
3381 _ (SYN_SENT, "tcp6-syn-sent") \
3382 _ (ESTABLISHED, "tcp6-established") \
3383 _ (RESET, "tcp6-reset") \
3384 _ (PUNT, "ip6-punt")
3386 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3389 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3390 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3392 tcp_connection_t *tc;
3397 for (i = 0; i < n_bufs; i++)
3399 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3401 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3402 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3404 tcp = vlib_buffer_get_current (bs[i]);
3405 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3411 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3413 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3415 *next = TCP_INPUT_NEXT_DROP;
3417 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3419 *next = TCP_INPUT_NEXT_PUNT;
3420 *error = TCP_ERROR_PUNT;
3424 *next = TCP_INPUT_NEXT_RESET;
3425 *error = TCP_ERROR_NO_LISTENER;
3429 always_inline tcp_connection_t *
3430 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3431 u8 is_ip4, u8 is_nolookup)
3433 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3434 int n_advance_bytes, n_data_bytes;
3435 transport_connection_t *tc;
3441 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3442 int ip_hdr_bytes = ip4_header_bytes (ip4);
3443 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3445 *error = TCP_ERROR_LENGTH;
3448 tcp = ip4_next_header (ip4);
3449 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3450 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3451 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3453 /* Length check. Checksum computed by ipx_local no need to compute again */
3454 if (PREDICT_FALSE (n_data_bytes < 0))
3456 *error = TCP_ERROR_LENGTH;
3461 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3462 &ip4->src_address, tcp->dst_port,
3464 TRANSPORT_PROTO_TCP, thread_index,
3469 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3470 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3472 *error = TCP_ERROR_LENGTH;
3475 tcp = ip6_next_header (ip6);
3476 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3477 n_advance_bytes = tcp_header_bytes (tcp);
3478 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3480 n_advance_bytes += sizeof (ip6[0]);
3482 if (PREDICT_FALSE (n_data_bytes < 0))
3484 *error = TCP_ERROR_LENGTH;
3491 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3493 ip4_main_t *im = &ip4_main;
3494 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3495 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3498 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3500 tcp->dst_port, tcp->src_port,
3501 TRANSPORT_PROTO_TCP,
3502 thread_index, &result);
3508 (transport_connection_t *) tcp_connection_get (vnet_buffer (b)->
3509 tcp.connection_index,
3512 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3513 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3514 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3515 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3516 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3518 vnet_buffer (b)->tcp.flags = 0;
3520 *error = result ? TCP_ERROR_NONE + result : *error;
3522 return tcp_get_connection_from_transport (tc);
3526 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3527 vlib_buffer_t * b, u16 * next, u32 * error)
3532 tcp = tcp_buffer_hdr (b);
3533 flags = tcp->flags & filter_flags;
3534 *next = tm->dispatch_table[tc->state][flags].next;
3535 *error = tm->dispatch_table[tc->state][flags].error;
3538 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3539 || *next == TCP_INPUT_NEXT_RESET))
3541 /* Overload tcp flags to store state */
3542 tcp_state_t state = tc->state;
3543 vnet_buffer (b)->tcp.flags = tc->state;
3545 if (*error == TCP_ERROR_DISPATCH)
3546 clib_warning ("tcp conn %u disp error state %U flags %U",
3547 tc->c_c_index, format_tcp_state, state,
3548 format_tcp_flags, (int) flags);
3553 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3554 vlib_frame_t * frame, int is_ip4, u8 is_nolookup)
3556 u32 n_left_from, *from, thread_index = vm->thread_index;
3557 tcp_main_t *tm = vnet_get_tcp_main ();
3558 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3559 u16 nexts[VLIB_FRAME_SIZE], *next;
3561 tcp_set_time_now (tcp_get_worker (thread_index));
3563 from = vlib_frame_vector_args (frame);
3564 n_left_from = frame->n_vectors;
3565 vlib_get_buffers (vm, from, bufs, n_left_from);
3570 while (n_left_from >= 4)
3572 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3573 tcp_connection_t *tc0, *tc1;
3576 vlib_prefetch_buffer_header (b[2], STORE);
3577 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3579 vlib_prefetch_buffer_header (b[3], STORE);
3580 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3583 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3585 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3587 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4,
3590 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3592 ASSERT (tcp_lookup_is_valid (tc0, b[0], tcp_buffer_hdr (b[0])));
3593 ASSERT (tcp_lookup_is_valid (tc1, b[1], tcp_buffer_hdr (b[1])));
3595 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3596 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3598 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3599 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3603 if (PREDICT_TRUE (tc0 != 0))
3605 ASSERT (tcp_lookup_is_valid (tc0, b[0], tcp_buffer_hdr (b[0])));
3606 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3607 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3610 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3612 if (PREDICT_TRUE (tc1 != 0))
3614 ASSERT (tcp_lookup_is_valid (tc1, b[1], tcp_buffer_hdr (b[1])));
3615 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3616 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3619 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3626 while (n_left_from > 0)
3628 tcp_connection_t *tc0;
3629 u32 error0 = TCP_ERROR_NO_LISTENER;
3631 if (n_left_from > 1)
3633 vlib_prefetch_buffer_header (b[1], STORE);
3634 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3637 next[0] = TCP_INPUT_NEXT_DROP;
3638 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3640 if (PREDICT_TRUE (tc0 != 0))
3642 ASSERT (tcp_lookup_is_valid (tc0, b[0], tcp_buffer_hdr (b[0])));
3643 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3644 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3647 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3654 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3655 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3657 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3658 return frame->n_vectors;
3661 VLIB_NODE_FN (tcp4_input_nolookup_node) (vlib_main_t * vm,
3662 vlib_node_runtime_t * node,
3663 vlib_frame_t * from_frame)
3665 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3666 1 /* is_nolookup */ );
3669 VLIB_NODE_FN (tcp6_input_nolookup_node) (vlib_main_t * vm,
3670 vlib_node_runtime_t * node,
3671 vlib_frame_t * from_frame)
3673 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3674 1 /* is_nolookup */ );
3678 VLIB_REGISTER_NODE (tcp4_input_nolookup_node) =
3680 .name = "tcp4-input-nolookup",
3681 /* Takes a vector of packets. */
3682 .vector_size = sizeof (u32),
3683 .n_errors = TCP_N_ERROR,
3684 .error_strings = tcp_error_strings,
3685 .n_next_nodes = TCP_INPUT_N_NEXT,
3688 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3689 foreach_tcp4_input_next
3692 .format_buffer = format_tcp_header,
3693 .format_trace = format_tcp_rx_trace,
3698 VLIB_REGISTER_NODE (tcp6_input_nolookup_node) =
3700 .name = "tcp6-input-nolookup",
3701 /* Takes a vector of packets. */
3702 .vector_size = sizeof (u32),
3703 .n_errors = TCP_N_ERROR,
3704 .error_strings = tcp_error_strings,
3705 .n_next_nodes = TCP_INPUT_N_NEXT,
3708 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3709 foreach_tcp6_input_next
3712 .format_buffer = format_tcp_header,
3713 .format_trace = format_tcp_rx_trace,
3717 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3718 vlib_frame_t * from_frame)
3720 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3721 0 /* is_nolookup */ );
3724 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3725 vlib_frame_t * from_frame)
3727 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3728 0 /* is_nolookup */ );
3732 VLIB_REGISTER_NODE (tcp4_input_node) =
3734 .name = "tcp4-input",
3735 /* Takes a vector of packets. */
3736 .vector_size = sizeof (u32),
3737 .n_errors = TCP_N_ERROR,
3738 .error_strings = tcp_error_strings,
3739 .n_next_nodes = TCP_INPUT_N_NEXT,
3742 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3743 foreach_tcp4_input_next
3746 .format_buffer = format_tcp_header,
3747 .format_trace = format_tcp_rx_trace,
3752 VLIB_REGISTER_NODE (tcp6_input_node) =
3754 .name = "tcp6-input",
3755 /* Takes a vector of packets. */
3756 .vector_size = sizeof (u32),
3757 .n_errors = TCP_N_ERROR,
3758 .error_strings = tcp_error_strings,
3759 .n_next_nodes = TCP_INPUT_N_NEXT,
3762 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3763 foreach_tcp6_input_next
3766 .format_buffer = format_tcp_header,
3767 .format_trace = format_tcp_rx_trace,
3771 #ifndef CLIB_MARCH_VARIANT
3773 tcp_dispatch_table_init (tcp_main_t * tm)
3776 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3777 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3779 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3780 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3783 #define _(t,f,n,e) \
3785 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3786 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3789 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3790 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3791 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3792 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3793 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3794 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3795 TCP_ERROR_ACK_INVALID);
3796 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3797 TCP_ERROR_SEGMENT_INVALID);
3798 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3799 TCP_ERROR_SEGMENT_INVALID);
3800 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3801 TCP_ERROR_INVALID_CONNECTION);
3802 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3803 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3804 TCP_ERROR_SEGMENT_INVALID);
3805 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3806 TCP_ERROR_SEGMENT_INVALID);
3807 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3809 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3810 TCP_ERROR_SEGMENT_INVALID);
3811 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3812 TCP_ERROR_SEGMENT_INVALID);
3813 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3814 TCP_ERROR_SEGMENT_INVALID);
3815 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3816 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3817 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3818 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3819 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3820 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3822 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3823 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3825 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3827 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3828 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3829 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3830 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3832 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3834 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3835 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3836 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3838 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3839 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3840 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3841 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3842 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3843 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3844 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3845 /* SYN-ACK for a SYN */
3846 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3848 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3849 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3850 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3852 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3853 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3855 /* ACK for for established connection -> tcp-established. */
3856 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3857 /* FIN for for established connection -> tcp-established. */
3858 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3859 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3861 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3863 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3864 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3865 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3867 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3868 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3869 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3870 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3871 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3872 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3873 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3874 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3876 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3877 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3879 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3881 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3882 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3883 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3884 /* ACK or FIN-ACK to our FIN */
3885 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3886 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3888 /* FIN in reply to our FIN from the other side */
3889 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3890 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3891 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3893 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3894 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3895 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3896 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3897 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3898 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3899 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3901 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3902 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3903 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3904 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3906 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3908 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3909 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3910 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3911 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3913 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3914 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3915 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3916 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3918 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3920 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3921 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3922 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3923 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3925 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3926 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3928 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3930 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3931 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3932 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3934 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3935 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3936 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3937 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3938 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3939 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3940 /* FIN confirming that the peer (app) has closed */
3941 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3942 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3943 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3945 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3946 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3948 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3949 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3951 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3952 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3954 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3955 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3956 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3957 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3959 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3961 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3962 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3963 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3965 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3966 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3967 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3968 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3969 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3970 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3971 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3972 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3974 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3975 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3977 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3979 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3980 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3981 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3982 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3983 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3985 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3986 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3988 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3989 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3990 * incoming segment not containing a RST causes a RST to be sent in
3992 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3993 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3994 TCP_ERROR_CONNECTION_CLOSED);
3995 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3996 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3997 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
4002 static clib_error_t *
4003 tcp_input_init (vlib_main_t * vm)
4005 clib_error_t *error = 0;
4006 tcp_main_t *tm = vnet_get_tcp_main ();
4008 if ((error = vlib_call_init_function (vm, tcp_init)))
4011 /* Initialize dispatch table. */
4012 tcp_dispatch_table_init (tm);
4017 VLIB_INIT_FUNCTION (tcp_input_init);
4019 #endif /* CLIB_MARCH_VARIANT */
4022 * fd.io coding-style-patch-verification: ON
4025 * eval: (c-set-style "gnu")