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_OPTION_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->flags & TCP_CONN_RATE_SAMPLE) && !(rs->flags & TCP_BTS_IS_RXT))
508 mrtt = rs->rtt_time * THZ;
514 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
516 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
517 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
518 mrtt = clib_max ((u32) (sample * THZ), 1);
519 /* Allow measuring of a new RTT */
522 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
523 * snd_una, i.e., the left side of the send window:
524 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
525 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
527 u32 now = tcp_tstamp (tc);
528 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
533 /* Ignore dubious measurements */
534 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
537 tcp_estimate_rtt (tc, mrtt);
541 /* If we got here something must've been ACKed so make sure boff is 0,
542 * even if mrtt is not valid since we update the rto lower */
550 tcp_estimate_initial_rtt (tcp_connection_t * tc)
552 u8 thread_index = vlib_num_workers ()? 1 : 0;
557 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
558 tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001);
559 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
564 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
565 mrtt = clib_max (mrtt, 1);
566 /* Due to retransmits we don't know the initial mrtt */
567 if (tc->rto_boff && mrtt > 1 * THZ)
569 tc->mrtt_us = (f64) mrtt *TCP_TICK;
572 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
573 tcp_estimate_rtt (tc, mrtt);
578 tcp_recovery_no_snd_space (tcp_connection_t * tc)
580 return (tcp_in_fastrecovery (tc)
581 && tcp_fastrecovery_prr_snd_space (tc) < tc->snd_mss)
582 || (tcp_in_recovery (tc)
583 && tcp_available_output_snd_space (tc) < tc->snd_mss);
587 * Dequeue bytes for connections that have received acks in last burst
590 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
592 u32 thread_index = wrk->vm->thread_index;
593 u32 *pending_deq_acked;
594 tcp_connection_t *tc;
597 if (!vec_len (wrk->pending_deq_acked))
600 pending_deq_acked = wrk->pending_deq_acked;
601 for (i = 0; i < vec_len (pending_deq_acked); i++)
603 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
604 tc->flags &= ~TCP_CONN_DEQ_PENDING;
608 /* Dequeue the newly ACKed bytes */
609 session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
611 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
613 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
615 if (seq_leq (tc->psh_seq, tc->snd_una))
616 tc->flags &= ~TCP_CONN_PSH_PENDING;
619 /* If everything has been acked, stop retransmit timer
620 * otherwise update. */
621 tcp_retransmit_timer_update (tc);
623 /* Update pacer based on our new cwnd estimate */
624 tcp_connection_tx_pacer_update (tc);
627 /* Reset the pacer if we've been idle, i.e., no data sent or if
628 * we're in recovery and snd space constrained */
629 if (tc->data_segs_out == tc->prev_dsegs_out
630 || tcp_recovery_no_snd_space (tc))
631 transport_connection_tx_pacer_reset_bucket (&tc->connection,
634 tc->prev_dsegs_out = tc->data_segs_out;
636 _vec_len (wrk->pending_deq_acked) = 0;
640 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
642 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
644 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
645 tc->flags |= TCP_CONN_DEQ_PENDING;
647 tc->burst_acked += tc->bytes_acked;
650 #ifndef CLIB_MARCH_VARIANT
652 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
654 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
655 return hole - sb->holes;
659 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
661 return hole->end - hole->start;
664 sack_scoreboard_hole_t *
665 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
667 if (index != TCP_INVALID_SACK_HOLE_INDEX)
668 return pool_elt_at_index (sb->holes, index);
672 sack_scoreboard_hole_t *
673 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
675 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
676 return pool_elt_at_index (sb->holes, hole->next);
680 sack_scoreboard_hole_t *
681 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
683 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
684 return pool_elt_at_index (sb->holes, hole->prev);
688 sack_scoreboard_hole_t *
689 scoreboard_first_hole (sack_scoreboard_t * sb)
691 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
692 return pool_elt_at_index (sb->holes, sb->head);
696 sack_scoreboard_hole_t *
697 scoreboard_last_hole (sack_scoreboard_t * sb)
699 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
700 return pool_elt_at_index (sb->holes, sb->tail);
705 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
707 sack_scoreboard_hole_t *next, *prev;
709 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
711 next = pool_elt_at_index (sb->holes, hole->next);
712 next->prev = hole->prev;
716 sb->tail = hole->prev;
719 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
721 prev = pool_elt_at_index (sb->holes, hole->prev);
722 prev->next = hole->next;
726 sb->head = hole->next;
729 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
730 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
732 /* Poison the entry */
734 clib_memset (hole, 0xfe, sizeof (*hole));
736 pool_put (sb->holes, hole);
739 static sack_scoreboard_hole_t *
740 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
743 sack_scoreboard_hole_t *hole, *next, *prev;
746 pool_get (sb->holes, hole);
747 clib_memset (hole, 0, sizeof (*hole));
751 hole_index = scoreboard_hole_index (sb, hole);
753 prev = scoreboard_get_hole (sb, prev_index);
756 hole->prev = prev_index;
757 hole->next = prev->next;
759 if ((next = scoreboard_next_hole (sb, hole)))
760 next->prev = hole_index;
762 sb->tail = hole_index;
764 prev->next = hole_index;
768 sb->head = hole_index;
769 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
770 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
777 scoreboard_update_sacked_rxt (sack_scoreboard_t * sb, u32 start, u32 end,
780 if (!has_rxt || seq_geq (start, sb->high_rxt))
784 seq_lt (end, sb->high_rxt) ? (end - start) : (sb->high_rxt - start);
788 scoreboard_update_bytes (sack_scoreboard_t * sb, u32 ack, u32 snd_mss)
790 sack_scoreboard_hole_t *left, *right;
791 u32 sacked = 0, blks = 0, old_sacked;
793 old_sacked = sb->sacked_bytes;
795 sb->last_lost_bytes = 0;
797 sb->sacked_bytes = 0;
799 right = scoreboard_last_hole (sb);
802 sb->sacked_bytes = sb->high_sacked - ack;
806 if (seq_gt (sb->high_sacked, right->end))
808 sacked = sb->high_sacked - right->end;
812 while (sacked < (TCP_DUPACK_THRESHOLD - 1) * snd_mss
813 && blks < TCP_DUPACK_THRESHOLD)
816 sb->lost_bytes += scoreboard_hole_bytes (right);
818 left = scoreboard_prev_hole (sb, right);
821 ASSERT (right->start == ack || sb->is_reneging);
822 sacked += right->start - ack;
827 sacked += right->start - left->end;
832 /* right is first lost */
835 sb->lost_bytes += scoreboard_hole_bytes (right);
836 sb->last_lost_bytes += right->is_lost ? 0 : (right->end - right->start);
838 left = scoreboard_prev_hole (sb, right);
841 ASSERT (right->start == ack || sb->is_reneging);
842 sacked += right->start - ack;
845 sacked += right->start - left->end;
849 sb->sacked_bytes = sacked;
850 sb->last_sacked_bytes = sacked - (old_sacked - sb->last_bytes_delivered);
854 * Figure out the next hole to retransmit
856 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
858 sack_scoreboard_hole_t *
859 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
860 sack_scoreboard_hole_t * start,
861 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
863 sack_scoreboard_hole_t *hole = 0;
865 hole = start ? start : scoreboard_first_hole (sb);
866 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
867 hole = scoreboard_next_hole (sb, hole);
869 /* Nothing, return */
872 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
876 /* Rule (1): if higher than rxt, less than high_sacked and lost */
877 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
879 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
883 /* Rule (2): available unsent data */
886 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
889 /* Rule (3): if hole not lost */
890 else if (seq_lt (hole->start, sb->high_sacked))
893 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
895 /* Rule (4): if hole beyond high_sacked */
898 ASSERT (seq_geq (hole->start, sb->high_sacked));
901 /* HighRxt MUST NOT be updated */
906 if (hole && seq_lt (sb->high_rxt, hole->start))
907 sb->high_rxt = hole->start;
913 scoreboard_init_rxt (sack_scoreboard_t * sb, u32 snd_una)
915 sack_scoreboard_hole_t *hole;
916 hole = scoreboard_first_hole (sb);
919 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
920 sb->cur_rxt_hole = sb->head;
922 sb->high_rxt = snd_una;
923 sb->rescue_rxt = snd_una - 1;
927 scoreboard_init (sack_scoreboard_t * sb)
929 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
930 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
931 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
935 scoreboard_clear (sack_scoreboard_t * sb)
937 sack_scoreboard_hole_t *hole;
938 while ((hole = scoreboard_first_hole (sb)))
940 scoreboard_remove_hole (sb, hole);
942 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
943 ASSERT (pool_elts (sb->holes) == 0);
944 sb->sacked_bytes = 0;
945 sb->last_sacked_bytes = 0;
946 sb->last_bytes_delivered = 0;
950 sb->last_lost_bytes = 0;
951 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
956 scoreboard_clear_reneging (sack_scoreboard_t * sb, u32 start, u32 end)
958 sack_scoreboard_hole_t *last_hole;
960 clib_warning ("sack reneging");
962 scoreboard_clear (sb);
963 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
965 last_hole->is_lost = 1;
966 sb->tail = scoreboard_hole_index (sb, last_hole);
967 sb->high_sacked = start;
968 scoreboard_init_rxt (sb, start);
971 #endif /* CLIB_MARCH_VARIANT */
974 * Test that scoreboard is sane after recovery
976 * Returns 1 if scoreboard is empty or if first hole beyond
980 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
982 sack_scoreboard_hole_t *hole;
983 hole = scoreboard_first_hole (&tc->sack_sb);
984 return (!hole || (seq_geq (hole->start, tc->snd_una)
985 && seq_lt (hole->end, tc->snd_nxt)));
988 #ifndef CLIB_MARCH_VARIANT
991 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
993 sack_scoreboard_hole_t *hole, *next_hole;
994 sack_scoreboard_t *sb = &tc->sack_sb;
995 sack_block_t *blk, *rcv_sacks;
996 u32 blk_index = 0, i, j;
999 sb->last_sacked_bytes = 0;
1000 sb->last_bytes_delivered = 0;
1003 if (!tcp_opts_sack (&tc->rcv_opts)
1004 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1007 has_rxt = tcp_in_cong_recovery (tc);
1009 /* Remove invalid blocks */
1010 blk = tc->rcv_opts.sacks;
1011 while (blk < vec_end (tc->rcv_opts.sacks))
1013 if (seq_lt (blk->start, blk->end)
1014 && seq_gt (blk->start, tc->snd_una)
1015 && seq_gt (blk->start, ack)
1016 && seq_lt (blk->start, tc->snd_nxt)
1017 && seq_leq (blk->end, tc->snd_nxt))
1022 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
1025 /* Add block for cumulative ack */
1026 if (seq_gt (ack, tc->snd_una))
1028 vec_add2 (tc->rcv_opts.sacks, blk, 1);
1029 blk->start = tc->snd_una;
1033 if (vec_len (tc->rcv_opts.sacks) == 0)
1036 tcp_scoreboard_trace_add (tc, ack);
1038 /* Make sure blocks are ordered */
1039 rcv_sacks = tc->rcv_opts.sacks;
1040 for (i = 0; i < vec_len (rcv_sacks); i++)
1041 for (j = i + 1; j < vec_len (rcv_sacks); j++)
1042 if (seq_lt (rcv_sacks[j].start, rcv_sacks[i].start))
1044 sack_block_t tmp = rcv_sacks[i];
1045 rcv_sacks[i] = rcv_sacks[j];
1049 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1051 /* Handle reneging as a special case */
1052 if (PREDICT_FALSE (sb->is_reneging))
1054 /* No holes, only sacked bytes */
1055 if (seq_leq (tc->snd_nxt, sb->high_sacked))
1057 /* No progress made so return */
1058 if (seq_leq (ack, tc->snd_una))
1061 /* Update sacked bytes delivered and return */
1062 sb->last_bytes_delivered = ack - tc->snd_una;
1063 sb->sacked_bytes -= sb->last_bytes_delivered;
1064 sb->is_reneging = seq_lt (ack, sb->high_sacked);
1068 /* New hole above high sacked. Add it and process normally */
1069 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1070 sb->high_sacked, tc->snd_nxt);
1071 sb->tail = scoreboard_hole_index (sb, hole);
1073 /* Not reneging and no holes. Insert the first that covers all
1074 * outstanding bytes */
1077 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1078 tc->snd_una, tc->snd_nxt);
1079 sb->tail = scoreboard_hole_index (sb, hole);
1081 sb->high_sacked = rcv_sacks[vec_len (rcv_sacks) - 1].end;
1085 /* If we have holes but snd_nxt is beyond the last hole, update
1086 * last hole end or add new hole after high sacked */
1087 hole = scoreboard_last_hole (sb);
1088 if (seq_gt (tc->snd_nxt, hole->end))
1090 if (seq_geq (hole->start, sb->high_sacked))
1092 hole->end = tc->snd_nxt;
1094 /* New hole after high sacked block */
1095 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1097 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1102 /* Keep track of max byte sacked for when the last hole
1104 sb->high_sacked = seq_max (rcv_sacks[vec_len (rcv_sacks) - 1].end,
1108 /* Walk the holes with the SACK blocks */
1109 hole = pool_elt_at_index (sb->holes, sb->head);
1111 if (PREDICT_FALSE (sb->is_reneging))
1112 sb->last_bytes_delivered += hole->start - tc->snd_una;
1114 while (hole && blk_index < vec_len (rcv_sacks))
1116 blk = &rcv_sacks[blk_index];
1117 if (seq_leq (blk->start, hole->start))
1119 /* Block covers hole. Remove hole */
1120 if (seq_geq (blk->end, hole->end))
1122 next_hole = scoreboard_next_hole (sb, hole);
1124 /* If covered by ack, compute delivered bytes */
1125 if (blk->end == ack)
1127 u32 sacked = next_hole ? next_hole->start : sb->high_sacked;
1128 if (PREDICT_FALSE (seq_lt (ack, sacked)))
1130 sb->last_bytes_delivered += ack - hole->end;
1131 sb->is_reneging = 1;
1135 sb->last_bytes_delivered += sacked - hole->end;
1136 sb->is_reneging = 0;
1139 scoreboard_update_sacked_rxt (sb, hole->start, hole->end,
1141 scoreboard_remove_hole (sb, hole);
1144 /* Partial 'head' overlap */
1147 if (seq_gt (blk->end, hole->start))
1149 scoreboard_update_sacked_rxt (sb, hole->start, blk->end,
1151 hole->start = blk->end;
1158 /* Hole must be split */
1159 if (seq_lt (blk->end, hole->end))
1161 u32 hole_index = scoreboard_hole_index (sb, hole);
1162 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1164 /* Pool might've moved */
1165 hole = scoreboard_get_hole (sb, hole_index);
1166 hole->end = blk->start;
1168 scoreboard_update_sacked_rxt (sb, blk->start, blk->end,
1172 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1174 else if (seq_lt (blk->start, hole->end))
1176 scoreboard_update_sacked_rxt (sb, blk->start, hole->end,
1178 hole->end = blk->start;
1180 hole = scoreboard_next_hole (sb, hole);
1184 scoreboard_update_bytes (sb, ack, tc->snd_mss);
1186 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1187 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1188 || sb->sacked_bytes <= tc->snd_nxt - seq_max (tc->snd_una, ack));
1189 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1190 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1191 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1192 || sb->is_reneging || sb->holes[sb->head].start == ack);
1193 ASSERT (sb->last_lost_bytes <= sb->lost_bytes);
1194 ASSERT ((ack - tc->snd_una) + sb->last_sacked_bytes
1195 - sb->last_bytes_delivered >= sb->rxt_sacked);
1196 ASSERT ((ack - tc->snd_una) >= tc->sack_sb.last_bytes_delivered
1197 || (tc->flags & TCP_CONN_FINSNT));
1199 TCP_EVT (TCP_EVT_CC_SCOREBOARD, tc);
1201 #endif /* CLIB_MARCH_VARIANT */
1204 * Try to update snd_wnd based on feedback received from peer.
1206 * If successful, and new window is 'effectively' 0, activate persist
1210 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1212 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1213 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1214 if (seq_lt (tc->snd_wl1, seq)
1215 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1217 tc->snd_wnd = snd_wnd;
1220 TCP_EVT (TCP_EVT_SND_WND, tc);
1222 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1224 /* Set persist timer if not set and we just got 0 wnd */
1225 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1226 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1227 tcp_persist_timer_set (tc);
1231 tcp_persist_timer_reset (tc);
1232 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1235 tcp_update_rto (tc);
1242 * Init loss recovery/fast recovery.
1244 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1245 * updated in @ref tcp_cc_handle_event after fast retransmit
1248 tcp_cc_init_congestion (tcp_connection_t * tc)
1250 tcp_fastrecovery_on (tc);
1251 tc->snd_congestion = tc->snd_nxt;
1252 tc->cwnd_acc_bytes = 0;
1253 tc->snd_rxt_bytes = 0;
1254 tc->rxt_delivered = 0;
1255 tc->prr_delivered = 0;
1256 tc->prr_start = tc->snd_una;
1257 tc->prev_ssthresh = tc->ssthresh;
1258 tc->prev_cwnd = tc->cwnd;
1260 tc->snd_rxt_ts = tcp_tstamp (tc);
1261 tcp_cc_congestion (tc);
1263 /* Post retransmit update cwnd to ssthresh and account for the
1264 * three segments that have left the network and should've been
1265 * buffered at the receiver XXX */
1266 if (!tcp_opts_sack_permitted (&tc->rcv_opts))
1267 tc->cwnd += 3 * tc->snd_mss;
1269 tc->fr_occurences += 1;
1270 TCP_EVT (TCP_EVT_CC_EVT, tc, 4);
1274 tcp_cc_congestion_undo (tcp_connection_t * tc)
1276 tc->cwnd = tc->prev_cwnd;
1277 tc->ssthresh = tc->prev_ssthresh;
1278 tcp_cc_undo_recovery (tc);
1279 ASSERT (tc->rto_boff == 0);
1280 TCP_EVT (TCP_EVT_CC_EVT, tc, 5);
1284 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1286 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1288 && tcp_opts_tstamp (&tc->rcv_opts)
1289 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1293 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1295 return (tcp_cc_is_spurious_timeout_rxt (tc));
1299 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1301 return (tc->sack_sb.lost_bytes
1302 || ((TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
1303 < tc->sack_sb.sacked_bytes));
1307 tcp_should_fastrecover (tcp_connection_t * tc, u8 has_sack)
1311 /* If of of the two conditions lower hold, reset dupacks because
1312 * we're probably after timeout (RFC6582 heuristics).
1313 * If Cumulative ack does not cover more than congestion threshold,
1315 * 1) The following doesn't hold: The congestion window is greater
1316 * than SMSS bytes and the difference between highest_ack
1317 * and prev_highest_ack is at most 4*SMSS bytes
1318 * 2) Echoed timestamp in the last non-dup ack does not equal the
1321 if (seq_leq (tc->snd_una, tc->snd_congestion)
1322 && ((!(tc->cwnd > tc->snd_mss
1323 && tc->bytes_acked <= 4 * tc->snd_mss))
1324 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1326 tc->rcv_dupacks = 0;
1330 return ((tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1331 || tcp_should_fastrecover_sack (tc));
1335 tcp_cc_recover (tcp_connection_t * tc)
1337 sack_scoreboard_hole_t *hole;
1340 ASSERT (tcp_in_cong_recovery (tc));
1342 if (tcp_cc_is_spurious_retransmit (tc))
1344 tcp_cc_congestion_undo (tc);
1348 tc->rcv_dupacks = 0;
1349 tc->prr_delivered = 0;
1350 tc->rxt_delivered = 0;
1351 tc->snd_rxt_bytes = 0;
1354 tc->flags &= ~TCP_CONN_RXT_PENDING;
1356 tcp_connection_tx_pacer_reset (tc, tc->cwnd, 0 /* start bucket */ );
1358 /* Previous recovery left us congested. Continue sending as part
1359 * of the current recovery event with an updated snd_congestion */
1360 if (tc->sack_sb.sacked_bytes)
1362 tc->snd_congestion = tc->snd_nxt;
1363 tc->snd_rxt_ts = tcp_tstamp (tc);
1364 tc->prr_start = tc->snd_una;
1365 scoreboard_init_rxt (&tc->sack_sb, tc->snd_una);
1366 tcp_program_retransmit (tc);
1370 hole = scoreboard_first_hole (&tc->sack_sb);
1371 if (hole && hole->start == tc->snd_una && hole->end == tc->snd_nxt)
1372 scoreboard_clear (&tc->sack_sb);
1374 if (!tcp_in_recovery (tc) && !is_spurious)
1375 tcp_cc_recovered (tc);
1377 tcp_fastrecovery_off (tc);
1378 tcp_fastrecovery_first_off (tc);
1379 tcp_recovery_off (tc);
1380 TCP_EVT (TCP_EVT_CC_EVT, tc, 3);
1382 ASSERT (tc->rto_boff == 0);
1383 ASSERT (!tcp_in_cong_recovery (tc));
1384 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1389 tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1391 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1393 /* Congestion avoidance */
1394 tcp_cc_rcv_ack (tc, rs);
1396 /* If a cumulative ack, make sure dupacks is 0 */
1397 tc->rcv_dupacks = 0;
1399 /* When dupacks hits the threshold we only enter fast retransmit if
1400 * cumulative ack covers more than snd_congestion. Should snd_una
1401 * wrap this test may fail under otherwise valid circumstances.
1402 * Therefore, proactively update snd_congestion when wrap detected. */
1404 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1405 && seq_gt (tc->snd_congestion, tc->snd_una)))
1406 tc->snd_congestion = tc->snd_una - 1;
1410 * One function to rule them all ... and in the darkness bind them
1413 tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs,
1416 u8 has_sack = tcp_opts_sack_permitted (&tc->rcv_opts);
1419 * If not in recovery, figure out if we should enter
1421 if (!tcp_in_cong_recovery (tc))
1426 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1427 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1429 if (tcp_should_fastrecover (tc, has_sack))
1431 tcp_cc_init_congestion (tc);
1434 scoreboard_init_rxt (&tc->sack_sb, tc->snd_una);
1436 tcp_connection_tx_pacer_reset (tc, tc->cwnd, 0 /* start bucket */ );
1437 tcp_program_retransmit (tc);
1444 * Already in recovery. See if we can exit and stop retransmitting
1447 if (seq_geq (tc->snd_una, tc->snd_congestion))
1449 /* If spurious return, we've already updated everything */
1450 if (tcp_cc_recover (tc))
1452 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1456 /* Treat as congestion avoidance ack */
1457 tcp_cc_rcv_ack (tc, rs);
1462 * Process (re)transmit feedback. Output path uses this to decide how much
1463 * more data to release into the network
1467 tc->rxt_delivered += tc->sack_sb.rxt_sacked;
1468 tc->prr_delivered += tc->bytes_acked + tc->sack_sb.last_sacked_bytes
1469 - tc->sack_sb.last_bytes_delivered;
1471 tcp_program_retransmit (tc);
1477 tc->rcv_dupacks += 1;
1478 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1480 tc->rxt_delivered = clib_max (tc->rxt_delivered + tc->bytes_acked,
1483 tc->prr_delivered += 1;
1485 tc->prr_delivered += tc->bytes_acked - tc->snd_mss * tc->rcv_dupacks;
1487 /* If partial ack, assume that the first un-acked segment was lost */
1488 if (tc->bytes_acked || tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1489 tcp_fastrecovery_first_on (tc);
1491 tcp_program_retransmit (tc);
1495 * Notify cc of the event
1498 if (!tc->bytes_acked)
1500 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1504 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1505 * reset dupacks to 0. Also needed if in congestion recovery */
1506 tc->rcv_dupacks = 0;
1508 if (tcp_in_recovery (tc))
1509 tcp_cc_rcv_ack (tc, rs);
1511 tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs);
1515 * Check if duplicate ack as per RFC5681 Sec. 2
1518 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
1521 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
1522 && seq_gt (tc->snd_nxt, tc->snd_una)
1523 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
1524 && (prev_snd_wnd == tc->snd_wnd));
1528 * Checks if ack is a congestion control event.
1531 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
1532 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
1534 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
1535 * defined to be 'duplicate' as well */
1536 *is_dack = tc->sack_sb.last_sacked_bytes
1537 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
1539 /* If reneging, wait for timer based retransmits */
1540 if (PREDICT_FALSE (tcp_is_lost_fin (tc) || tc->sack_sb.is_reneging))
1543 return (*is_dack || tcp_in_cong_recovery (tc));
1547 * Process incoming ACK
1550 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1551 tcp_header_t * th, u32 * error)
1553 u32 prev_snd_wnd, prev_snd_una;
1554 tcp_rate_sample_t rs = { 0 };
1557 TCP_EVT (TCP_EVT_CC_STAT, tc);
1559 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1560 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1562 /* We've probably entered recovery and the peer still has some
1563 * of the data we've sent. Update snd_nxt and accept the ack */
1564 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1565 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1567 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1571 tc->errors.above_ack_wnd += 1;
1572 *error = TCP_ERROR_ACK_FUTURE;
1573 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 0, vnet_buffer (b)->tcp.ack_number);
1577 /* If old ACK, probably it's an old dupack */
1578 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1580 tc->errors.below_ack_wnd += 1;
1581 *error = TCP_ERROR_ACK_OLD;
1582 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 1, vnet_buffer (b)->tcp.ack_number);
1583 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1584 tcp_cc_handle_event (tc, 0, 1);
1585 /* Don't drop yet */
1592 * Looks okay, process feedback
1595 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1596 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1598 prev_snd_wnd = tc->snd_wnd;
1599 prev_snd_una = tc->snd_una;
1600 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1601 vnet_buffer (b)->tcp.ack_number,
1602 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1603 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1604 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
1605 tcp_validate_txf_size (tc, tc->bytes_acked);
1607 if (tc->flags & TCP_CONN_RATE_SAMPLE)
1608 tcp_bt_sample_delivery_rate (tc, &rs);
1610 tcp_program_dequeue (wrk, tc);
1612 if (tc->bytes_acked)
1613 tcp_update_rtt (tc, &rs, vnet_buffer (b)->tcp.ack_number);
1615 TCP_EVT (TCP_EVT_ACK_RCVD, tc);
1618 * Check if we have congestion event
1621 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1623 tcp_cc_handle_event (tc, &rs, is_dack);
1624 tc->dupacks_in += is_dack;
1625 if (!tcp_in_cong_recovery (tc))
1627 *error = TCP_ERROR_ACK_OK;
1630 *error = TCP_ERROR_ACK_DUP;
1631 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1637 * Update congestion control (slow start/congestion avoidance)
1639 tcp_cc_update (tc, &rs);
1640 *error = TCP_ERROR_ACK_OK;
1645 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1647 if (!tcp_disconnect_pending (tc))
1649 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1650 tcp_disconnect_pending_on (tc);
1655 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1657 u32 thread_index, *pending_disconnects;
1658 tcp_connection_t *tc;
1661 if (!vec_len (wrk->pending_disconnects))
1664 thread_index = wrk->vm->thread_index;
1665 pending_disconnects = wrk->pending_disconnects;
1666 for (i = 0; i < vec_len (pending_disconnects); i++)
1668 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1669 tcp_disconnect_pending_off (tc);
1670 session_transport_closing_notify (&tc->connection);
1672 _vec_len (wrk->pending_disconnects) = 0;
1676 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1679 /* Reject out-of-order fins */
1680 if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt)
1683 /* Account for the FIN and send ack */
1685 tcp_program_ack (tc);
1686 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1687 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1688 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1689 tcp_program_disconnect (wrk, tc);
1690 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
1691 TCP_EVT (TCP_EVT_FIN_RCVD, tc);
1692 *error = TCP_ERROR_FIN_RCVD;
1695 #ifndef CLIB_MARCH_VARIANT
1697 tcp_sack_vector_is_sane (sack_block_t * sacks)
1700 for (i = 1; i < vec_len (sacks); i++)
1702 if (sacks[i - 1].end == sacks[i].start)
1709 * Build SACK list as per RFC2018.
1711 * Makes sure the first block contains the segment that generated the current
1712 * ACK and the following ones are the ones most recently reported in SACK
1715 * @param tc TCP connection for which the SACK list is updated
1716 * @param start Start sequence number of the newest SACK block
1717 * @param end End sequence of the newest SACK block
1720 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1722 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1725 /* If the first segment is ooo add it to the list. Last write might've moved
1726 * rcv_nxt over the first segment. */
1727 if (seq_lt (tc->rcv_nxt, start))
1729 vec_add2 (new_list, block, 1);
1730 block->start = start;
1734 /* Find the blocks still worth keeping. */
1735 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1737 /* Discard if rcv_nxt advanced beyond current block */
1738 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1741 /* Merge or drop if segment overlapped by the new segment */
1742 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1743 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1745 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1746 new_list[0].start = tc->snd_sacks[i].start;
1747 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1748 new_list[0].end = tc->snd_sacks[i].end;
1752 /* Save to new SACK list if we have space. */
1753 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1754 vec_add1 (new_list, tc->snd_sacks[i]);
1757 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1759 /* Replace old vector with new one */
1760 vec_reset_length (tc->snd_sacks);
1761 tc->snd_sacks_fl = tc->snd_sacks;
1762 tc->snd_sacks = new_list;
1764 /* Segments should not 'touch' */
1765 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1769 tcp_sack_list_bytes (tcp_connection_t * tc)
1772 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1773 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1776 #endif /* CLIB_MARCH_VARIANT */
1778 /** Enqueue data for delivery to application */
1780 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1783 int written, error = TCP_ERROR_ENQUEUED;
1785 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1787 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1788 1 /* queue event */ , 1);
1789 tc->bytes_in += written;
1791 TCP_EVT (TCP_EVT_INPUT, tc, 0, data_len, written);
1793 /* Update rcv_nxt */
1794 if (PREDICT_TRUE (written == data_len))
1796 tc->rcv_nxt += written;
1798 /* If more data written than expected, account for out-of-order bytes. */
1799 else if (written > data_len)
1801 tc->rcv_nxt += written;
1802 TCP_EVT (TCP_EVT_CC_INPUT, tc, data_len, written);
1804 else if (written > 0)
1806 /* We've written something but FIFO is probably full now */
1807 tc->rcv_nxt += written;
1808 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1812 return TCP_ERROR_FIFO_FULL;
1815 /* Update SACK list if need be */
1816 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1818 /* Remove SACK blocks that have been delivered */
1819 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1825 /** Enqueue out-of-order data */
1827 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1833 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1836 /* Enqueue out-of-order data with relative offset */
1837 rv = session_enqueue_stream_connection (&tc->connection, b,
1838 vnet_buffer (b)->tcp.seq_number -
1839 tc->rcv_nxt, 0 /* queue event */ ,
1842 /* Nothing written */
1845 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, 0);
1846 return TCP_ERROR_FIFO_FULL;
1849 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1850 tc->bytes_in += data_len;
1852 /* Update SACK list if in use */
1853 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1855 ooo_segment_t *newest;
1858 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1860 /* Get the newest segment from the fifo */
1861 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1864 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1865 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1866 start = tc->rcv_nxt + offset;
1867 end = start + ooo_segment_length (s0->rx_fifo, newest);
1868 tcp_update_sack_list (tc, start, end);
1869 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1870 TCP_EVT (TCP_EVT_CC_SACKS, tc);
1874 return TCP_ERROR_ENQUEUED_OOO;
1878 * Check if ACK could be delayed. If ack can be delayed, it should return
1879 * true for a full frame. If we're always acking return 0.
1882 tcp_can_delack (tcp_connection_t * tc)
1884 /* Send ack if ... */
1886 /* just sent a rcv wnd 0
1887 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1888 /* constrained to send ack */
1889 || (tc->flags & TCP_CONN_SNDACK) != 0
1890 /* we're almost out of tx wnd */
1891 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1898 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1900 u32 discard, first = b->current_length;
1901 vlib_main_t *vm = vlib_get_main ();
1903 /* Handle multi-buffer segments */
1904 if (n_bytes_to_drop > b->current_length)
1906 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1910 discard = clib_min (n_bytes_to_drop, b->current_length);
1911 vlib_buffer_advance (b, discard);
1912 b = vlib_get_buffer (vm, b->next_buffer);
1913 n_bytes_to_drop -= discard;
1915 while (n_bytes_to_drop);
1916 if (n_bytes_to_drop > first)
1917 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1920 vlib_buffer_advance (b, n_bytes_to_drop);
1921 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1926 * Receive buffer for connection and handle acks
1928 * It handles both in order or out-of-order data.
1931 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1934 u32 error, n_bytes_to_drop, n_data_bytes;
1936 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1937 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1938 ASSERT (n_data_bytes);
1939 tc->data_segs_in += 1;
1941 /* Handle out-of-order data */
1942 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1944 /* Old sequence numbers allowed through because they overlapped
1946 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1948 /* Completely in the past (possible retransmit). Ack
1949 * retransmissions since we may not have any data to send */
1950 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1952 tcp_program_ack (tc);
1953 error = TCP_ERROR_SEGMENT_OLD;
1957 /* Chop off the bytes in the past and see if what is left
1958 * can be enqueued in order */
1959 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1960 n_data_bytes -= n_bytes_to_drop;
1961 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1962 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1964 error = TCP_ERROR_SEGMENT_OLD;
1970 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1971 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1972 tcp_program_dupack (tc);
1973 TCP_EVT (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1974 tc->errors.above_data_wnd += seq_gt (vnet_buffer (b)->tcp.seq_end,
1975 tc->rcv_las + tc->rcv_wnd);
1981 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1982 * segments can be enqueued after fifo tail offset changes. */
1983 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1984 if (tcp_can_delack (tc))
1986 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1987 tcp_timer_set (tc, TCP_TIMER_DELACK, tcp_cfg.delack_time);
1991 tcp_program_ack (tc);
1999 tcp_header_t tcp_header;
2000 tcp_connection_t tcp_connection;
2004 format_tcp_rx_trace (u8 * s, va_list * args)
2006 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2007 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2008 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2009 u32 indent = format_get_indent (s);
2011 s = format (s, "%U\n%U%U",
2012 format_tcp_header, &t->tcp_header, 128,
2013 format_white_space, indent,
2014 format_tcp_connection, &t->tcp_connection, 1);
2020 format_tcp_rx_trace_short (u8 * s, va_list * args)
2022 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2023 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2024 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2026 s = format (s, "%d -> %d (%U)",
2027 clib_net_to_host_u16 (t->tcp_header.dst_port),
2028 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2029 t->tcp_connection.state);
2035 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2036 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2040 clib_memcpy_fast (&t0->tcp_connection, tc0,
2041 sizeof (t0->tcp_connection));
2045 th0 = tcp_buffer_hdr (b0);
2047 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2051 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2052 vlib_frame_t * frame, u8 is_ip4)
2056 n_left = frame->n_vectors;
2057 from = vlib_frame_vector_args (frame);
2061 tcp_connection_t *tc0;
2068 b0 = vlib_get_buffer (vm, bi0);
2070 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2072 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2073 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2075 th0 = tcp_buffer_hdr (b0);
2076 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2085 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2086 u8 is_ip4, u32 evt, u32 val)
2089 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2091 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2094 #define tcp_maybe_inc_counter(node_id, err, count) \
2096 if (next0 != tcp_next_drop (is_ip4)) \
2097 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2098 tcp6_##node_id##_node.index, is_ip4, err, \
2101 #define tcp_inc_counter(node_id, err, count) \
2102 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2103 tcp6_##node_id##_node.index, is_ip4, \
2105 #define tcp_maybe_inc_err_counter(cnts, err) \
2107 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2109 #define tcp_inc_err_counter(cnts, err, val) \
2113 #define tcp_store_err_counters(node_id, cnts) \
2116 for (i = 0; i < TCP_N_ERROR; i++) \
2118 tcp_inc_counter(node_id, i, cnts[i]); \
2123 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2124 vlib_frame_t * frame, int is_ip4)
2126 u32 thread_index = vm->thread_index, errors = 0;
2127 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2128 u32 n_left_from, *from, *first_buffer;
2129 u16 err_counters[TCP_N_ERROR] = { 0 };
2131 if (node->flags & VLIB_NODE_FLAG_TRACE)
2132 tcp_established_trace_frame (vm, node, frame, is_ip4);
2134 first_buffer = from = vlib_frame_vector_args (frame);
2135 n_left_from = frame->n_vectors;
2137 while (n_left_from > 0)
2139 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2142 tcp_connection_t *tc0;
2144 if (n_left_from > 1)
2147 pb = vlib_get_buffer (vm, from[1]);
2148 vlib_prefetch_buffer_header (pb, LOAD);
2149 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2156 b0 = vlib_get_buffer (vm, bi0);
2157 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2160 if (PREDICT_FALSE (tc0 == 0))
2162 error0 = TCP_ERROR_INVALID_CONNECTION;
2166 th0 = tcp_buffer_hdr (b0);
2168 /* TODO header prediction fast path */
2170 /* 1-4: check SEQ, RST, SYN */
2171 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2173 TCP_EVT (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2177 /* 5: check the ACK field */
2178 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2181 /* 6: check the URG bit TODO */
2183 /* 7: process the segment text */
2184 if (vnet_buffer (b0)->tcp.data_len)
2185 error0 = tcp_segment_rcv (wrk, tc0, b0);
2187 /* 8: check the FIN bit */
2188 if (PREDICT_FALSE (tcp_is_fin (th0)))
2189 tcp_rcv_fin (wrk, tc0, b0, &error0);
2192 tcp_inc_err_counter (err_counters, error0, 1);
2195 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2197 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2198 tcp_store_err_counters (established, err_counters);
2199 tcp_handle_postponed_dequeues (wrk);
2200 tcp_handle_disconnects (wrk);
2201 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2203 return frame->n_vectors;
2206 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2207 vlib_node_runtime_t * node,
2208 vlib_frame_t * from_frame)
2210 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2213 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2214 vlib_node_runtime_t * node,
2215 vlib_frame_t * from_frame)
2217 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2221 VLIB_REGISTER_NODE (tcp4_established_node) =
2223 .name = "tcp4-established",
2224 /* Takes a vector of packets. */
2225 .vector_size = sizeof (u32),
2226 .n_errors = TCP_N_ERROR,
2227 .error_strings = tcp_error_strings,
2228 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2231 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2232 foreach_tcp_state_next
2235 .format_trace = format_tcp_rx_trace_short,
2240 VLIB_REGISTER_NODE (tcp6_established_node) =
2242 .name = "tcp6-established",
2243 /* Takes a vector of packets. */
2244 .vector_size = sizeof (u32),
2245 .n_errors = TCP_N_ERROR,
2246 .error_strings = tcp_error_strings,
2247 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2250 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2251 foreach_tcp_state_next
2254 .format_trace = format_tcp_rx_trace_short,
2260 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2262 transport_connection_t *tmp = 0;
2269 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2272 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2273 && (tc->state == TCP_STATE_LISTEN
2274 || tc->c_rmt_port == hdr->src_port));
2278 handle = session_lookup_half_open_handle (&tc->connection);
2279 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2280 tc->c_proto, tc->c_is_ip4);
2284 if (tmp->lcl_port == hdr->dst_port
2285 && tmp->rmt_port == hdr->src_port)
2287 TCP_DBG ("half-open is valid!");
2295 * Lookup transport connection
2297 static tcp_connection_t *
2298 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2302 transport_connection_t *tconn;
2303 tcp_connection_t *tc;
2308 ip4 = vlib_buffer_get_current (b);
2309 tcp = ip4_next_header (ip4);
2310 tconn = session_lookup_connection_wt4 (fib_index,
2315 TRANSPORT_PROTO_TCP,
2316 thread_index, &is_filtered);
2317 tc = tcp_get_connection_from_transport (tconn);
2318 ASSERT (tcp_lookup_is_valid (tc, tcp));
2323 ip6 = vlib_buffer_get_current (b);
2324 tcp = ip6_next_header (ip6);
2325 tconn = session_lookup_connection_wt6 (fib_index,
2330 TRANSPORT_PROTO_TCP,
2331 thread_index, &is_filtered);
2332 tc = tcp_get_connection_from_transport (tconn);
2333 ASSERT (tcp_lookup_is_valid (tc, tcp));
2339 tcp_check_tx_offload (tcp_connection_t * tc, int is_ipv4)
2341 vnet_main_t *vnm = vnet_get_main ();
2342 const dpo_id_t *dpo;
2343 const load_balance_t *lb;
2344 vnet_hw_interface_t *hw_if;
2345 u32 sw_if_idx, lb_idx;
2349 ip4_address_t *dst_addr = &(tc->c_rmt_ip.ip4);
2350 lb_idx = ip4_fib_forwarding_lookup (tc->c_fib_index, dst_addr);
2354 ip6_address_t *dst_addr = &(tc->c_rmt_ip.ip6);
2355 lb_idx = ip6_fib_table_fwding_lookup (tc->c_fib_index, dst_addr);
2358 lb = load_balance_get (lb_idx);
2359 dpo = load_balance_get_bucket_i (lb, 0);
2361 sw_if_idx = dpo->dpoi_index;
2362 hw_if = vnet_get_sup_hw_interface (vnm, sw_if_idx);
2365 ((hw_if->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO) == 0) ? 0 : 1;
2370 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2371 vlib_frame_t * from_frame, int is_ip4)
2373 u32 n_left_from, *from, *first_buffer, errors = 0;
2374 u32 my_thread_index = vm->thread_index;
2375 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2377 from = first_buffer = vlib_frame_vector_args (from_frame);
2378 n_left_from = from_frame->n_vectors;
2380 while (n_left_from > 0)
2382 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2383 tcp_connection_t *tc0, *new_tc0;
2384 tcp_header_t *tcp0 = 0;
2392 b0 = vlib_get_buffer (vm, bi0);
2394 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2395 if (PREDICT_FALSE (tc0 == 0))
2397 error0 = TCP_ERROR_INVALID_CONNECTION;
2401 /* Half-open completed recently but the connection was't removed
2402 * yet by the owning thread */
2403 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2405 /* Make sure the connection actually exists */
2406 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2407 my_thread_index, is_ip4));
2408 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2412 ack0 = vnet_buffer (b0)->tcp.ack_number;
2413 seq0 = vnet_buffer (b0)->tcp.seq_number;
2414 tcp0 = tcp_buffer_hdr (b0);
2416 /* Crude check to see if the connection handle does not match
2417 * the packet. Probably connection just switched to established */
2418 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2419 || tcp0->src_port != tc0->c_rmt_port))
2421 error0 = TCP_ERROR_INVALID_CONNECTION;
2425 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2426 && !tcp_syn (tcp0)))
2428 error0 = TCP_ERROR_SEGMENT_INVALID;
2432 /* SYNs consume sequence numbers */
2433 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2436 * 1. check the ACK bit
2440 * If the ACK bit is set
2441 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2442 * the RST bit is set, if so drop the segment and return)
2443 * <SEQ=SEG.ACK><CTL=RST>
2444 * and discard the segment. Return.
2445 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2449 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2451 if (!tcp_rst (tcp0))
2452 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2453 error0 = TCP_ERROR_RCV_WND;
2457 /* Make sure ACK is valid */
2458 if (seq_gt (tc0->snd_una, ack0))
2460 error0 = TCP_ERROR_ACK_INVALID;
2466 * 2. check the RST bit
2471 /* If ACK is acceptable, signal client that peer is not
2472 * willing to accept connection and drop connection*/
2474 tcp_connection_reset (tc0);
2475 error0 = TCP_ERROR_RST_RCVD;
2480 * 3. check the security and precedence (skipped)
2484 * 4. check the SYN bit
2487 /* No SYN flag. Drop. */
2488 if (!tcp_syn (tcp0))
2490 error0 = TCP_ERROR_SEGMENT_INVALID;
2495 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2497 error0 = TCP_ERROR_OPTIONS;
2501 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2502 * current thread pool. */
2503 new_tc0 = tcp_connection_alloc_w_base (my_thread_index, tc0);
2504 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2505 new_tc0->irs = seq0;
2506 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2507 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2509 /* If this is not the owning thread, wait for syn retransmit to
2510 * expire and cleanup then */
2511 if (tcp_half_open_connection_cleanup (tc0))
2512 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2514 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2516 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2517 new_tc0->tsval_recent_age = tcp_time_now ();
2520 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2521 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2523 new_tc0->rcv_wscale = 0;
2525 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2526 << new_tc0->snd_wscale;
2527 new_tc0->snd_wl1 = seq0;
2528 new_tc0->snd_wl2 = ack0;
2530 tcp_connection_init_vars (new_tc0);
2532 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2533 if (PREDICT_TRUE (tcp_ack (tcp0)))
2535 /* Our SYN is ACKed: we have iss < ack = snd_una */
2537 /* TODO Dequeue acknowledged segments if we support Fast Open */
2538 new_tc0->snd_una = ack0;
2539 new_tc0->state = TCP_STATE_ESTABLISHED;
2541 /* Make sure las is initialized for the wnd computation */
2542 new_tc0->rcv_las = new_tc0->rcv_nxt;
2544 /* Notify app that we have connection. If session layer can't
2545 * allocate session send reset */
2546 if (session_stream_connect_notify (&new_tc0->connection, 0))
2548 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2549 tcp_connection_cleanup (new_tc0);
2550 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2554 new_tc0->tx_fifo_size =
2555 transport_tx_fifo_size (&new_tc0->connection);
2556 /* Update rtt with the syn-ack sample */
2557 tcp_estimate_initial_rtt (new_tc0);
2558 TCP_EVT (TCP_EVT_SYNACK_RCVD, new_tc0);
2559 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2561 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2564 new_tc0->state = TCP_STATE_SYN_RCVD;
2566 /* Notify app that we have connection */
2567 if (session_stream_connect_notify (&new_tc0->connection, 0))
2569 tcp_connection_cleanup (new_tc0);
2570 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2571 TCP_EVT (TCP_EVT_RST_SENT, tc0);
2572 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2576 new_tc0->tx_fifo_size =
2577 transport_tx_fifo_size (&new_tc0->connection);
2578 new_tc0->rtt_ts = 0;
2579 tcp_init_snd_vars (new_tc0);
2580 tcp_send_synack (new_tc0);
2581 error0 = TCP_ERROR_SYNS_RCVD;
2585 tcp_check_tx_offload (new_tc0, is_ip4);
2587 /* Read data, if any */
2588 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2590 clib_warning ("rcvd data in syn-sent");
2591 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2592 if (error0 == TCP_ERROR_ACK_OK)
2593 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2597 tcp_program_ack (new_tc0);
2602 tcp_inc_counter (syn_sent, error0, 1);
2603 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2605 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2606 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2607 clib_memcpy_fast (&t0->tcp_connection, tc0,
2608 sizeof (t0->tcp_connection));
2612 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2614 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2615 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2617 return from_frame->n_vectors;
2620 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2621 vlib_node_runtime_t * node,
2622 vlib_frame_t * from_frame)
2624 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2627 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2628 vlib_node_runtime_t * node,
2629 vlib_frame_t * from_frame)
2631 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2635 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2637 .name = "tcp4-syn-sent",
2638 /* Takes a vector of packets. */
2639 .vector_size = sizeof (u32),
2640 .n_errors = TCP_N_ERROR,
2641 .error_strings = tcp_error_strings,
2642 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2645 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2646 foreach_tcp_state_next
2649 .format_trace = format_tcp_rx_trace_short,
2654 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2656 .name = "tcp6-syn-sent",
2657 /* Takes a vector of packets. */
2658 .vector_size = sizeof (u32),
2659 .n_errors = TCP_N_ERROR,
2660 .error_strings = tcp_error_strings,
2661 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2664 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2665 foreach_tcp_state_next
2668 .format_trace = format_tcp_rx_trace_short,
2673 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2674 * as per RFC793 p. 64
2677 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2678 vlib_frame_t * from_frame, int is_ip4)
2680 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2681 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2682 u32 n_left_from, *from, max_dequeue;
2684 from = first_buffer = vlib_frame_vector_args (from_frame);
2685 n_left_from = from_frame->n_vectors;
2687 while (n_left_from > 0)
2689 u32 bi0, error0 = TCP_ERROR_NONE;
2690 tcp_header_t *tcp0 = 0;
2691 tcp_connection_t *tc0;
2699 b0 = vlib_get_buffer (vm, bi0);
2700 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2702 if (PREDICT_FALSE (tc0 == 0))
2704 error0 = TCP_ERROR_INVALID_CONNECTION;
2708 tcp0 = tcp_buffer_hdr (b0);
2709 is_fin0 = tcp_is_fin (tcp0);
2713 tcp_connection_t *tmp;
2714 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2716 if (tmp->state != tc0->state)
2718 if (tc0->state != TCP_STATE_CLOSED)
2719 clib_warning ("state changed");
2725 * Special treatment for CLOSED
2727 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2729 error0 = TCP_ERROR_CONNECTION_CLOSED;
2734 * For all other states (except LISTEN)
2737 /* 1-4: check SEQ, RST, SYN */
2738 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2741 /* 5: check the ACK field */
2744 case TCP_STATE_SYN_RCVD:
2746 /* Make sure the segment is exactly right */
2747 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2749 tcp_connection_reset (tc0);
2750 error0 = TCP_ERROR_SEGMENT_INVALID;
2755 * If the segment acknowledgment is not acceptable, form a
2757 * <SEQ=SEG.ACK><CTL=RST>
2760 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2762 tcp_connection_reset (tc0);
2766 /* Update rtt and rto */
2767 tcp_estimate_initial_rtt (tc0);
2768 tcp_connection_tx_pacer_update (tc0);
2770 /* Switch state to ESTABLISHED */
2771 tc0->state = TCP_STATE_ESTABLISHED;
2772 TCP_EVT (TCP_EVT_STATE_CHANGE, tc0);
2774 tcp_check_tx_offload (tc0, is_ip4);
2776 /* Initialize session variables */
2777 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2778 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2779 << tc0->rcv_opts.wscale;
2780 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2781 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2783 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2784 tcp_retransmit_timer_reset (tc0);
2785 if (session_stream_accept_notify (&tc0->connection))
2787 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2788 tcp_connection_reset (tc0);
2791 error0 = TCP_ERROR_ACK_OK;
2793 case TCP_STATE_ESTABLISHED:
2794 /* We can get packets in established state here because they
2795 * were enqueued before state change */
2796 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2800 case TCP_STATE_FIN_WAIT_1:
2801 /* In addition to the processing for the ESTABLISHED state, if
2802 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2803 * continue processing in that state. */
2804 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2807 /* Still have to send the FIN */
2808 if (tc0->flags & TCP_CONN_FINPNDG)
2810 /* TX fifo finally drained */
2811 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2812 if (max_dequeue <= tc0->burst_acked)
2814 /* If a fin was received and data was acked extend wait */
2815 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
2816 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2817 tcp_cfg.closewait_time);
2819 /* If FIN is ACKed */
2820 else if (tc0->snd_una == tc0->snd_nxt)
2822 /* Stop all retransmit timers because we have nothing more
2824 tcp_connection_timers_reset (tc0);
2826 /* We already have a FIN but didn't transition to CLOSING
2827 * because of outstanding tx data. Close the connection. */
2828 if (tc0->flags & TCP_CONN_FINRCVD)
2830 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2831 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE,
2832 tcp_cfg.cleanup_time);
2833 session_transport_closed_notify (&tc0->connection);
2837 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2838 /* Enable waitclose because we're willing to wait for peer's
2839 * FIN but not indefinitely. */
2840 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait2_time);
2842 /* Don't try to deq the FIN acked */
2843 if (tc0->burst_acked > 1)
2844 session_tx_fifo_dequeue_drop (&tc0->connection,
2845 tc0->burst_acked - 1);
2846 tc0->burst_acked = 0;
2849 case TCP_STATE_FIN_WAIT_2:
2850 /* In addition to the processing for the ESTABLISHED state, if
2851 * the retransmission queue is empty, the user's CLOSE can be
2852 * acknowledged ("ok") but do not delete the TCB. */
2853 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2855 tc0->burst_acked = 0;
2857 case TCP_STATE_CLOSE_WAIT:
2858 /* Do the same processing as for the ESTABLISHED state. */
2859 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2862 if (!(tc0->flags & TCP_CONN_FINPNDG))
2865 /* Still have outstanding tx data */
2866 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2867 if (max_dequeue > tc0->burst_acked)
2871 tcp_connection_timers_reset (tc0);
2872 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2873 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2875 case TCP_STATE_CLOSING:
2876 /* In addition to the processing for the ESTABLISHED state, if
2877 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2878 * otherwise ignore the segment. */
2879 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2882 if (tc0->snd_una != tc0->snd_nxt)
2885 tcp_connection_timers_reset (tc0);
2886 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2887 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2888 session_transport_closed_notify (&tc0->connection);
2892 case TCP_STATE_LAST_ACK:
2893 /* The only thing that [should] arrive in this state is an
2894 * acknowledgment of our FIN. If our FIN is now acknowledged,
2895 * delete the TCB, enter the CLOSED state, and return. */
2897 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2900 /* Apparently our ACK for the peer's FIN was lost */
2901 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2907 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2908 session_transport_closed_notify (&tc0->connection);
2910 /* Don't free the connection from the data path since
2911 * we can't ensure that we have no packets already enqueued
2912 * to output. Rely instead on the waitclose timer */
2913 tcp_connection_timers_reset (tc0);
2914 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
2919 case TCP_STATE_TIME_WAIT:
2920 /* The only thing that can arrive in this state is a
2921 * retransmission of the remote FIN. Acknowledge it, and restart
2922 * the 2 MSL timeout. */
2924 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2930 tcp_program_ack (tc0);
2931 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2939 /* 6: check the URG bit TODO */
2941 /* 7: process the segment text */
2944 case TCP_STATE_ESTABLISHED:
2945 case TCP_STATE_FIN_WAIT_1:
2946 case TCP_STATE_FIN_WAIT_2:
2947 if (vnet_buffer (b0)->tcp.data_len)
2948 error0 = tcp_segment_rcv (wrk, tc0, b0);
2950 case TCP_STATE_CLOSE_WAIT:
2951 case TCP_STATE_CLOSING:
2952 case TCP_STATE_LAST_ACK:
2953 case TCP_STATE_TIME_WAIT:
2954 /* This should not occur, since a FIN has been received from the
2955 * remote side. Ignore the segment text. */
2959 /* 8: check the FIN bit */
2963 TCP_EVT (TCP_EVT_FIN_RCVD, tc0);
2967 case TCP_STATE_ESTABLISHED:
2968 /* Account for the FIN and send ack */
2970 tcp_program_ack (tc0);
2971 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2972 tcp_program_disconnect (wrk, tc0);
2973 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
2975 case TCP_STATE_SYN_RCVD:
2976 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2977 * notified yet, set a cleanup timer instead of relying on
2978 * disconnect notify and the implicit close call. */
2979 tcp_connection_timers_reset (tc0);
2982 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2983 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2985 case TCP_STATE_CLOSE_WAIT:
2986 case TCP_STATE_CLOSING:
2987 case TCP_STATE_LAST_ACK:
2990 case TCP_STATE_FIN_WAIT_1:
2993 if (tc0->flags & TCP_CONN_FINPNDG)
2995 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
2996 * sending it. Since we already received a fin, do not wait
2998 tc0->flags |= TCP_CONN_FINRCVD;
2999 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
3000 tcp_cfg.closewait_time);
3004 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
3005 tcp_program_ack (tc0);
3006 /* Wait for ACK for our FIN but not forever */
3007 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
3008 tcp_cfg.closing_time);
3011 case TCP_STATE_FIN_WAIT_2:
3012 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
3014 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
3015 tcp_connection_timers_reset (tc0);
3016 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3017 tcp_program_ack (tc0);
3018 session_transport_closed_notify (&tc0->connection);
3020 case TCP_STATE_TIME_WAIT:
3021 /* Remain in the TIME-WAIT state. Restart the time-wait
3024 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3027 error0 = TCP_ERROR_FIN_RCVD;
3031 tcp_inc_counter (rcv_process, error0, 1);
3032 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3034 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3035 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3039 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
3041 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3042 tcp_handle_postponed_dequeues (wrk);
3043 tcp_handle_disconnects (wrk);
3044 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3046 return from_frame->n_vectors;
3049 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
3050 vlib_node_runtime_t * node,
3051 vlib_frame_t * from_frame)
3053 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3056 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
3057 vlib_node_runtime_t * node,
3058 vlib_frame_t * from_frame)
3060 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3064 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3066 .name = "tcp4-rcv-process",
3067 /* Takes a vector of packets. */
3068 .vector_size = sizeof (u32),
3069 .n_errors = TCP_N_ERROR,
3070 .error_strings = tcp_error_strings,
3071 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3074 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3075 foreach_tcp_state_next
3078 .format_trace = format_tcp_rx_trace_short,
3083 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3085 .name = "tcp6-rcv-process",
3086 /* Takes a vector of packets. */
3087 .vector_size = sizeof (u32),
3088 .n_errors = TCP_N_ERROR,
3089 .error_strings = tcp_error_strings,
3090 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3093 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3094 foreach_tcp_state_next
3097 .format_trace = format_tcp_rx_trace_short,
3102 * LISTEN state processing as per RFC 793 p. 65
3105 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3106 vlib_frame_t * from_frame, int is_ip4)
3108 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3109 u32 my_thread_index = vm->thread_index;
3111 from = first_buffer = vlib_frame_vector_args (from_frame);
3112 n_left_from = from_frame->n_vectors;
3114 while (n_left_from > 0)
3119 tcp_header_t *th0 = 0;
3120 tcp_connection_t *lc0;
3123 tcp_connection_t *child0;
3124 u32 error0 = TCP_ERROR_NONE;
3130 b0 = vlib_get_buffer (vm, bi0);
3131 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3135 ip40 = vlib_buffer_get_current (b0);
3136 th0 = ip4_next_header (ip40);
3140 ip60 = vlib_buffer_get_current (b0);
3141 th0 = ip6_next_header (ip60);
3144 /* Create child session. For syn-flood protection use filter */
3146 /* 1. first check for an RST: handled in dispatch */
3147 /* if (tcp_rst (th0))
3151 /* 2. second check for an ACK: handled in dispatch */
3152 /* if (tcp_ack (th0))
3154 tcp_send_reset (b0, is_ip4);
3159 /* 3. check for a SYN (did that already) */
3161 /* Make sure connection wasn't just created */
3162 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3164 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3166 error0 = TCP_ERROR_CREATE_EXISTS;
3170 /* Create child session and send SYN-ACK */
3171 child0 = tcp_connection_alloc (my_thread_index);
3172 child0->c_lcl_port = th0->dst_port;
3173 child0->c_rmt_port = th0->src_port;
3174 child0->c_is_ip4 = is_ip4;
3175 child0->state = TCP_STATE_SYN_RCVD;
3176 child0->c_fib_index = lc0->c_fib_index;
3177 child0->cc_algo = lc0->cc_algo;
3181 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3182 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3186 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3187 sizeof (ip6_address_t));
3188 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3189 sizeof (ip6_address_t));
3192 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3194 error0 = TCP_ERROR_OPTIONS;
3195 tcp_connection_free (child0);
3199 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3200 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3201 child0->rcv_las = child0->rcv_nxt;
3202 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3204 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3205 * segments are used to initialize PAWS. */
3206 if (tcp_opts_tstamp (&child0->rcv_opts))
3208 child0->tsval_recent = child0->rcv_opts.tsval;
3209 child0->tsval_recent_age = tcp_time_now ();
3212 if (tcp_opts_wscale (&child0->rcv_opts))
3213 child0->snd_wscale = child0->rcv_opts.wscale;
3215 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3216 << child0->snd_wscale;
3217 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3218 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3220 tcp_connection_init_vars (child0);
3221 child0->rto = TCP_RTO_MIN;
3223 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3224 lc0->c_thread_index, 0 /* notify */ ))
3226 tcp_connection_cleanup (child0);
3227 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3231 TCP_EVT (TCP_EVT_SYN_RCVD, child0, 1);
3232 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3233 tcp_send_synack (child0);
3237 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3239 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3240 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3241 clib_memcpy_fast (&t0->tcp_connection, lc0,
3242 sizeof (t0->tcp_connection));
3245 n_syns += (error0 == TCP_ERROR_NONE);
3248 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3249 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3251 return from_frame->n_vectors;
3254 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3255 vlib_frame_t * from_frame)
3257 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3260 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3261 vlib_frame_t * from_frame)
3263 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3267 VLIB_REGISTER_NODE (tcp4_listen_node) =
3269 .name = "tcp4-listen",
3270 /* Takes a vector of packets. */
3271 .vector_size = sizeof (u32),
3272 .n_errors = TCP_N_ERROR,
3273 .error_strings = tcp_error_strings,
3274 .n_next_nodes = TCP_LISTEN_N_NEXT,
3277 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3278 foreach_tcp_state_next
3281 .format_trace = format_tcp_rx_trace_short,
3286 VLIB_REGISTER_NODE (tcp6_listen_node) =
3288 .name = "tcp6-listen",
3289 /* Takes a vector of packets. */
3290 .vector_size = sizeof (u32),
3291 .n_errors = TCP_N_ERROR,
3292 .error_strings = tcp_error_strings,
3293 .n_next_nodes = TCP_LISTEN_N_NEXT,
3296 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3297 foreach_tcp_state_next
3300 .format_trace = format_tcp_rx_trace_short,
3304 typedef enum _tcp_input_next
3306 TCP_INPUT_NEXT_DROP,
3307 TCP_INPUT_NEXT_LISTEN,
3308 TCP_INPUT_NEXT_RCV_PROCESS,
3309 TCP_INPUT_NEXT_SYN_SENT,
3310 TCP_INPUT_NEXT_ESTABLISHED,
3311 TCP_INPUT_NEXT_RESET,
3312 TCP_INPUT_NEXT_PUNT,
3316 #define foreach_tcp4_input_next \
3317 _ (DROP, "ip4-drop") \
3318 _ (LISTEN, "tcp4-listen") \
3319 _ (RCV_PROCESS, "tcp4-rcv-process") \
3320 _ (SYN_SENT, "tcp4-syn-sent") \
3321 _ (ESTABLISHED, "tcp4-established") \
3322 _ (RESET, "tcp4-reset") \
3323 _ (PUNT, "ip4-punt")
3325 #define foreach_tcp6_input_next \
3326 _ (DROP, "ip6-drop") \
3327 _ (LISTEN, "tcp6-listen") \
3328 _ (RCV_PROCESS, "tcp6-rcv-process") \
3329 _ (SYN_SENT, "tcp6-syn-sent") \
3330 _ (ESTABLISHED, "tcp6-established") \
3331 _ (RESET, "tcp6-reset") \
3332 _ (PUNT, "ip6-punt")
3334 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3337 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3338 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3340 tcp_connection_t *tc;
3345 for (i = 0; i < n_bufs; i++)
3347 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3349 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3350 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3352 tcp = vlib_buffer_get_current (bs[i]);
3353 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3359 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3361 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3363 *next = TCP_INPUT_NEXT_DROP;
3365 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3367 *next = TCP_INPUT_NEXT_PUNT;
3368 *error = TCP_ERROR_PUNT;
3372 *next = TCP_INPUT_NEXT_RESET;
3373 *error = TCP_ERROR_NO_LISTENER;
3377 always_inline tcp_connection_t *
3378 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3379 u8 is_ip4, u8 is_nolookup)
3381 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3382 int n_advance_bytes, n_data_bytes;
3383 transport_connection_t *tc;
3389 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3390 int ip_hdr_bytes = ip4_header_bytes (ip4);
3391 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3393 *error = TCP_ERROR_LENGTH;
3396 tcp = ip4_next_header (ip4);
3397 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3398 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3399 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3401 /* Length check. Checksum computed by ipx_local no need to compute again */
3402 if (PREDICT_FALSE (n_data_bytes < 0))
3404 *error = TCP_ERROR_LENGTH;
3409 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3410 &ip4->src_address, tcp->dst_port,
3412 TRANSPORT_PROTO_TCP, thread_index,
3417 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3418 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3420 *error = TCP_ERROR_LENGTH;
3423 tcp = ip6_next_header (ip6);
3424 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3425 n_advance_bytes = tcp_header_bytes (tcp);
3426 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3428 n_advance_bytes += sizeof (ip6[0]);
3430 if (PREDICT_FALSE (n_data_bytes < 0))
3432 *error = TCP_ERROR_LENGTH;
3439 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3441 ip4_main_t *im = &ip4_main;
3442 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3443 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3446 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3448 tcp->dst_port, tcp->src_port,
3449 TRANSPORT_PROTO_TCP,
3450 thread_index, &result);
3456 (transport_connection_t *) tcp_connection_get (vnet_buffer (b)->
3457 tcp.connection_index,
3460 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3461 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3462 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3463 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3464 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3466 vnet_buffer (b)->tcp.flags = 0;
3468 *error = result ? TCP_ERROR_NONE + result : *error;
3470 return tcp_get_connection_from_transport (tc);
3474 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3475 vlib_buffer_t * b, u16 * next, u32 * error)
3480 tcp = tcp_buffer_hdr (b);
3481 flags = tcp->flags & filter_flags;
3482 *next = tm->dispatch_table[tc->state][flags].next;
3483 *error = tm->dispatch_table[tc->state][flags].error;
3486 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3487 || *next == TCP_INPUT_NEXT_RESET))
3489 /* Overload tcp flags to store state */
3490 tcp_state_t state = tc->state;
3491 vnet_buffer (b)->tcp.flags = tc->state;
3493 if (*error == TCP_ERROR_DISPATCH)
3494 clib_warning ("tcp conn %u disp error state %U flags %U",
3495 tc->c_c_index, format_tcp_state, state,
3496 format_tcp_flags, (int) flags);
3501 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3502 vlib_frame_t * frame, int is_ip4, u8 is_nolookup)
3504 u32 n_left_from, *from, thread_index = vm->thread_index;
3505 tcp_main_t *tm = vnet_get_tcp_main ();
3506 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3507 u16 nexts[VLIB_FRAME_SIZE], *next;
3509 tcp_set_time_now (tcp_get_worker (thread_index));
3511 from = vlib_frame_vector_args (frame);
3512 n_left_from = frame->n_vectors;
3513 vlib_get_buffers (vm, from, bufs, n_left_from);
3518 while (n_left_from >= 4)
3520 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3521 tcp_connection_t *tc0, *tc1;
3524 vlib_prefetch_buffer_header (b[2], STORE);
3525 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3527 vlib_prefetch_buffer_header (b[3], STORE);
3528 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3531 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3533 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3535 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4,
3538 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3540 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3541 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3543 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3544 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3546 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3547 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3551 if (PREDICT_TRUE (tc0 != 0))
3553 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3554 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3555 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3558 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3560 if (PREDICT_TRUE (tc1 != 0))
3562 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3563 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3564 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3567 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3574 while (n_left_from > 0)
3576 tcp_connection_t *tc0;
3577 u32 error0 = TCP_ERROR_NO_LISTENER;
3579 if (n_left_from > 1)
3581 vlib_prefetch_buffer_header (b[1], STORE);
3582 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3585 next[0] = TCP_INPUT_NEXT_DROP;
3586 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3588 if (PREDICT_TRUE (tc0 != 0))
3590 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3591 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3592 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3595 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3602 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3603 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3605 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3606 return frame->n_vectors;
3609 VLIB_NODE_FN (tcp4_input_nolookup_node) (vlib_main_t * vm,
3610 vlib_node_runtime_t * node,
3611 vlib_frame_t * from_frame)
3613 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3614 1 /* is_nolookup */ );
3617 VLIB_NODE_FN (tcp6_input_nolookup_node) (vlib_main_t * vm,
3618 vlib_node_runtime_t * node,
3619 vlib_frame_t * from_frame)
3621 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3622 1 /* is_nolookup */ );
3626 VLIB_REGISTER_NODE (tcp4_input_nolookup_node) =
3628 .name = "tcp4-input-nolookup",
3629 /* Takes a vector of packets. */
3630 .vector_size = sizeof (u32),
3631 .n_errors = TCP_N_ERROR,
3632 .error_strings = tcp_error_strings,
3633 .n_next_nodes = TCP_INPUT_N_NEXT,
3636 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3637 foreach_tcp4_input_next
3640 .format_buffer = format_tcp_header,
3641 .format_trace = format_tcp_rx_trace,
3646 VLIB_REGISTER_NODE (tcp6_input_nolookup_node) =
3648 .name = "tcp6-input-nolookup",
3649 /* Takes a vector of packets. */
3650 .vector_size = sizeof (u32),
3651 .n_errors = TCP_N_ERROR,
3652 .error_strings = tcp_error_strings,
3653 .n_next_nodes = TCP_INPUT_N_NEXT,
3656 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3657 foreach_tcp6_input_next
3660 .format_buffer = format_tcp_header,
3661 .format_trace = format_tcp_rx_trace,
3665 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3666 vlib_frame_t * from_frame)
3668 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3669 0 /* is_nolookup */ );
3672 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3673 vlib_frame_t * from_frame)
3675 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3676 0 /* is_nolookup */ );
3680 VLIB_REGISTER_NODE (tcp4_input_node) =
3682 .name = "tcp4-input",
3683 /* Takes a vector of packets. */
3684 .vector_size = sizeof (u32),
3685 .n_errors = TCP_N_ERROR,
3686 .error_strings = tcp_error_strings,
3687 .n_next_nodes = TCP_INPUT_N_NEXT,
3690 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3691 foreach_tcp4_input_next
3694 .format_buffer = format_tcp_header,
3695 .format_trace = format_tcp_rx_trace,
3700 VLIB_REGISTER_NODE (tcp6_input_node) =
3702 .name = "tcp6-input",
3703 /* Takes a vector of packets. */
3704 .vector_size = sizeof (u32),
3705 .n_errors = TCP_N_ERROR,
3706 .error_strings = tcp_error_strings,
3707 .n_next_nodes = TCP_INPUT_N_NEXT,
3710 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3711 foreach_tcp6_input_next
3714 .format_buffer = format_tcp_header,
3715 .format_trace = format_tcp_rx_trace,
3719 #ifndef CLIB_MARCH_VARIANT
3721 tcp_dispatch_table_init (tcp_main_t * tm)
3724 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3725 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3727 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3728 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3731 #define _(t,f,n,e) \
3733 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3734 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3737 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3738 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3739 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3740 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3741 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3742 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3743 TCP_ERROR_ACK_INVALID);
3744 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3745 TCP_ERROR_SEGMENT_INVALID);
3746 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3747 TCP_ERROR_SEGMENT_INVALID);
3748 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3749 TCP_ERROR_INVALID_CONNECTION);
3750 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3751 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3752 TCP_ERROR_SEGMENT_INVALID);
3753 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3754 TCP_ERROR_SEGMENT_INVALID);
3755 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3757 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3758 TCP_ERROR_SEGMENT_INVALID);
3759 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3760 TCP_ERROR_SEGMENT_INVALID);
3761 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3762 TCP_ERROR_SEGMENT_INVALID);
3763 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3764 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3765 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3766 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3767 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3768 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3770 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3771 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3773 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3775 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3776 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3777 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3778 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3780 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3782 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3783 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3784 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3786 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3787 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3788 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3789 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3790 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3791 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3792 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3793 /* SYN-ACK for a SYN */
3794 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3796 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3797 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3798 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3800 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3801 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3803 /* ACK for for established connection -> tcp-established. */
3804 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3805 /* FIN for for established connection -> tcp-established. */
3806 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3807 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3809 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3811 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3812 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3813 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3815 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3816 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3817 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3818 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3819 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3820 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3821 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3822 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3824 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3825 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3827 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3829 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3830 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3831 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3832 /* ACK or FIN-ACK to our FIN */
3833 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3834 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3836 /* FIN in reply to our FIN from the other side */
3837 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3838 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3839 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3841 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3842 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3843 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3844 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3845 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3846 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3847 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3849 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3850 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3851 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3852 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3854 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3856 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3857 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3858 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3859 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3861 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3862 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3863 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3864 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3866 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3868 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3869 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3870 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3871 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3873 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3874 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3876 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3878 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3879 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3880 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3882 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3883 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3884 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3885 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3886 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3887 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3888 /* FIN confirming that the peer (app) has closed */
3889 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3890 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3891 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3893 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3894 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3896 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3897 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3899 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3900 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3902 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3903 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3904 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3905 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3907 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3909 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3910 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3911 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3913 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3914 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3915 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3916 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3917 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3918 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3919 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3920 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3922 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3923 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3925 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3927 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3928 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3929 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3930 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3931 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3933 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3934 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3936 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3937 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3938 * incoming segment not containing a RST causes a RST to be sent in
3940 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3941 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3942 TCP_ERROR_CONNECTION_CLOSED);
3943 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3944 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3945 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3950 static clib_error_t *
3951 tcp_input_init (vlib_main_t * vm)
3953 clib_error_t *error = 0;
3954 tcp_main_t *tm = vnet_get_tcp_main ();
3956 if ((error = vlib_call_init_function (vm, tcp_init)))
3959 /* Initialize dispatch table. */
3960 tcp_dispatch_table_init (tm);
3965 VLIB_INIT_FUNCTION (tcp_input_init);
3967 #endif /* CLIB_MARCH_VARIANT */
3970 * fd.io coding-style-patch-verification: ON
3973 * eval: (c-set-style "gnu")