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, 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) || tc->sack_sb.sacked_bytes)
505 if (tcp_in_recovery (tc))
510 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
512 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
513 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
514 mrtt = clib_max ((u32) (sample * THZ), 1);
515 /* Allow measuring of a new RTT */
518 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
519 * snd_una, i.e., the left side of the send window:
520 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
521 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
523 u32 now = tcp_tstamp (tc);
524 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
527 /* Ignore dubious measurements */
528 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
531 tcp_estimate_rtt (tc, mrtt);
535 /* If we got here something must've been ACKed so make sure boff is 0,
536 * even if mrtt is not valid since we update the rto lower */
544 tcp_estimate_initial_rtt (tcp_connection_t * tc)
546 u8 thread_index = vlib_num_workers ()? 1 : 0;
551 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
552 tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001);
553 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
558 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
559 mrtt = clib_max (mrtt, 1);
560 /* Due to retransmits we don't know the initial mrtt */
561 if (tc->rto_boff && mrtt > 1 * THZ)
563 tc->mrtt_us = (f64) mrtt *TCP_TICK;
566 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
567 tcp_estimate_rtt (tc, mrtt);
572 * Dequeue bytes for connections that have received acks in last burst
575 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
577 u32 thread_index = wrk->vm->thread_index;
578 u32 *pending_deq_acked;
579 tcp_connection_t *tc;
582 if (!vec_len (wrk->pending_deq_acked))
585 pending_deq_acked = wrk->pending_deq_acked;
586 for (i = 0; i < vec_len (pending_deq_acked); i++)
588 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
589 tc->flags &= ~TCP_CONN_DEQ_PENDING;
591 if (PREDICT_FALSE (!tc->burst_acked))
594 /* Dequeue the newly ACKed bytes */
595 session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
597 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
599 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
601 if (seq_leq (tc->psh_seq, tc->snd_una))
602 tc->flags &= ~TCP_CONN_PSH_PENDING;
605 /* If everything has been acked, stop retransmit timer
606 * otherwise update. */
607 tcp_retransmit_timer_update (tc);
609 /* If not congested, update pacer based on our new
611 if (!tcp_in_fastrecovery (tc))
612 tcp_connection_tx_pacer_update (tc);
614 _vec_len (wrk->pending_deq_acked) = 0;
618 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
620 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
622 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
623 tc->flags |= TCP_CONN_DEQ_PENDING;
625 tc->burst_acked += tc->bytes_acked;
629 * Check if duplicate ack as per RFC5681 Sec. 2
632 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
635 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
636 && seq_gt (tc->snd_nxt, tc->snd_una)
637 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
638 && (prev_snd_wnd == tc->snd_wnd));
642 * Checks if ack is a congestion control event.
645 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
646 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
648 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
649 * defined to be 'duplicate' */
650 *is_dack = tc->sack_sb.last_sacked_bytes
651 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
653 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
656 #ifndef CLIB_MARCH_VARIANT
658 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
660 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
661 return hole - sb->holes;
665 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
667 return hole->end - hole->start;
670 sack_scoreboard_hole_t *
671 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
673 if (index != TCP_INVALID_SACK_HOLE_INDEX)
674 return pool_elt_at_index (sb->holes, index);
678 sack_scoreboard_hole_t *
679 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
681 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
682 return pool_elt_at_index (sb->holes, hole->next);
686 sack_scoreboard_hole_t *
687 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
689 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
690 return pool_elt_at_index (sb->holes, hole->prev);
694 sack_scoreboard_hole_t *
695 scoreboard_first_hole (sack_scoreboard_t * sb)
697 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
698 return pool_elt_at_index (sb->holes, sb->head);
702 sack_scoreboard_hole_t *
703 scoreboard_last_hole (sack_scoreboard_t * sb)
705 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
706 return pool_elt_at_index (sb->holes, sb->tail);
711 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
713 sack_scoreboard_hole_t *next, *prev;
715 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
717 next = pool_elt_at_index (sb->holes, hole->next);
718 next->prev = hole->prev;
722 sb->tail = hole->prev;
725 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
727 prev = pool_elt_at_index (sb->holes, hole->prev);
728 prev->next = hole->next;
732 sb->head = hole->next;
735 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
736 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
738 /* Poison the entry */
740 clib_memset (hole, 0xfe, sizeof (*hole));
742 pool_put (sb->holes, hole);
745 static sack_scoreboard_hole_t *
746 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
749 sack_scoreboard_hole_t *hole, *next, *prev;
752 pool_get (sb->holes, hole);
753 clib_memset (hole, 0, sizeof (*hole));
757 hole_index = scoreboard_hole_index (sb, hole);
759 prev = scoreboard_get_hole (sb, prev_index);
762 hole->prev = prev_index;
763 hole->next = prev->next;
765 if ((next = scoreboard_next_hole (sb, hole)))
766 next->prev = hole_index;
768 sb->tail = hole_index;
770 prev->next = hole_index;
774 sb->head = hole_index;
775 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
776 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
781 #endif /* CLIB_MARCH_VARIANT */
783 #ifndef CLIB_MARCH_VARIANT
786 scoreboard_update_bytes (sack_scoreboard_t * sb, u32 ack, u32 snd_mss)
788 sack_scoreboard_hole_t *left, *right;
789 u32 sacked = 0, blks = 0, old_sacked;
791 old_sacked = sb->sacked_bytes;
793 sb->last_lost_bytes = 0;
795 sb->sacked_bytes = 0;
797 right = scoreboard_last_hole (sb);
800 sb->sacked_bytes = sb->high_sacked - ack;
804 if (seq_gt (sb->high_sacked, right->end))
806 sacked = sb->high_sacked - right->end;
810 while (sacked < (TCP_DUPACK_THRESHOLD - 1) * snd_mss
811 && blks < TCP_DUPACK_THRESHOLD)
814 sb->lost_bytes += scoreboard_hole_bytes (right);
816 left = scoreboard_prev_hole (sb, right);
819 ASSERT (right->start == ack || sb->is_reneging);
820 sacked += right->start - ack;
825 sacked += right->start - left->end;
830 /* right is first lost */
833 sb->lost_bytes += scoreboard_hole_bytes (right);
834 sb->last_lost_bytes += right->is_lost ? 0 : right->end - right->start;
836 left = scoreboard_prev_hole (sb, right);
839 ASSERT (right->start == ack || sb->is_reneging);
840 sacked += right->start - ack;
843 sacked += right->start - left->end;
847 sb->sacked_bytes = sacked;
848 sb->last_sacked_bytes = sacked - (old_sacked - sb->last_bytes_delivered);
852 * Figure out the next hole to retransmit
854 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
856 sack_scoreboard_hole_t *
857 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
858 sack_scoreboard_hole_t * start,
859 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
861 sack_scoreboard_hole_t *hole = 0;
863 hole = start ? start : scoreboard_first_hole (sb);
864 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
865 hole = scoreboard_next_hole (sb, hole);
867 /* Nothing, return */
870 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
874 /* Rule (1): if higher than rxt, less than high_sacked and lost */
875 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
877 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
881 /* Rule (2): available unsent data */
884 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
887 /* Rule (3): if hole not lost */
888 else if (seq_lt (hole->start, sb->high_sacked))
891 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
893 /* Rule (4): if hole beyond high_sacked */
896 ASSERT (seq_geq (hole->start, sb->high_sacked));
899 /* HighRxt MUST NOT be updated */
904 if (hole && seq_lt (sb->high_rxt, hole->start))
905 sb->high_rxt = hole->start;
909 #endif /* CLIB_MARCH_VARIANT */
912 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
914 sack_scoreboard_hole_t *hole;
915 hole = scoreboard_first_hole (sb);
918 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
919 sb->cur_rxt_hole = sb->head;
921 sb->high_rxt = snd_una;
922 sb->rescue_rxt = snd_una - 1;
925 #ifndef CLIB_MARCH_VARIANT
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;
954 #endif /* CLIB_MARCH_VARIANT */
957 * Test that scoreboard is sane after recovery
959 * Returns 1 if scoreboard is empty or if first hole beyond
963 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
965 sack_scoreboard_hole_t *hole;
966 hole = scoreboard_first_hole (&tc->sack_sb);
967 return (!hole || (seq_geq (hole->start, tc->snd_una)
968 && seq_lt (hole->end, tc->snd_nxt)));
971 #ifndef CLIB_MARCH_VARIANT
974 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
976 sack_scoreboard_hole_t *hole, *next_hole;
977 sack_scoreboard_t *sb = &tc->sack_sb;
978 sack_block_t *blk, *rcv_sacks;
979 u32 blk_index = 0, i, j;
981 sb->last_sacked_bytes = 0;
982 sb->last_bytes_delivered = 0;
984 if (!tcp_opts_sack (&tc->rcv_opts)
985 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
988 /* Remove invalid blocks */
989 blk = tc->rcv_opts.sacks;
990 while (blk < vec_end (tc->rcv_opts.sacks))
992 if (seq_lt (blk->start, blk->end)
993 && seq_gt (blk->start, tc->snd_una)
994 && seq_gt (blk->start, ack)
995 && seq_lt (blk->start, tc->snd_nxt)
996 && seq_leq (blk->end, tc->snd_nxt))
1001 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
1004 /* Add block for cumulative ack */
1005 if (seq_gt (ack, tc->snd_una))
1007 vec_add2 (tc->rcv_opts.sacks, blk, 1);
1008 blk->start = tc->snd_una;
1012 if (vec_len (tc->rcv_opts.sacks) == 0)
1015 tcp_scoreboard_trace_add (tc, ack);
1017 /* Make sure blocks are ordered */
1018 rcv_sacks = tc->rcv_opts.sacks;
1019 for (i = 0; i < vec_len (rcv_sacks); i++)
1020 for (j = i + 1; j < vec_len (rcv_sacks); j++)
1021 if (seq_lt (rcv_sacks[j].start, rcv_sacks[i].start))
1023 sack_block_t tmp = rcv_sacks[i];
1024 rcv_sacks[i] = rcv_sacks[j];
1028 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1030 /* Handle reneging as a special case */
1031 if (PREDICT_FALSE (sb->is_reneging))
1033 /* No holes, only sacked bytes */
1034 if (seq_leq (tc->snd_nxt, sb->high_sacked))
1036 /* No progress made so return */
1037 if (seq_leq (ack, tc->snd_una))
1040 /* Update sacked bytes delivered and return */
1041 sb->last_bytes_delivered = ack - tc->snd_una;
1042 sb->sacked_bytes -= sb->last_bytes_delivered;
1043 sb->is_reneging = seq_lt (ack, sb->high_sacked);
1047 /* New hole above high sacked. Add it and process normally */
1048 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1049 sb->high_sacked, tc->snd_nxt);
1050 sb->tail = scoreboard_hole_index (sb, hole);
1052 /* Not reneging and no holes. Insert the first that covers all
1053 * outstanding bytes */
1056 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1057 tc->snd_una, tc->snd_nxt);
1058 sb->tail = scoreboard_hole_index (sb, hole);
1060 sb->high_sacked = rcv_sacks[vec_len (rcv_sacks) - 1].end;
1064 /* If we have holes but snd_nxt is beyond the last hole, update
1065 * last hole end or add new hole after high sacked */
1066 hole = scoreboard_last_hole (sb);
1067 if (seq_gt (tc->snd_nxt, hole->end))
1069 if (seq_geq (hole->start, sb->high_sacked))
1071 hole->end = tc->snd_nxt;
1073 /* New hole after high sacked block */
1074 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1076 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1081 /* Keep track of max byte sacked for when the last hole
1083 sb->high_sacked = seq_max (rcv_sacks[vec_len (rcv_sacks) - 1].end,
1087 /* Walk the holes with the SACK blocks */
1088 hole = pool_elt_at_index (sb->holes, sb->head);
1090 if (PREDICT_FALSE (sb->is_reneging))
1091 sb->last_bytes_delivered += hole->start - tc->snd_una;
1093 while (hole && blk_index < vec_len (rcv_sacks))
1095 blk = &rcv_sacks[blk_index];
1096 if (seq_leq (blk->start, hole->start))
1098 /* Block covers hole. Remove hole */
1099 if (seq_geq (blk->end, hole->end))
1101 next_hole = scoreboard_next_hole (sb, hole);
1103 /* If covered by ack, compute delivered bytes */
1104 if (blk->end == ack)
1106 u32 sacked = next_hole ? next_hole->start : sb->high_sacked;
1107 if (PREDICT_FALSE (seq_lt (ack, sacked)))
1109 sb->last_bytes_delivered += ack - hole->end;
1110 sb->is_reneging = 1;
1114 sb->last_bytes_delivered += sacked - hole->end;
1115 sb->is_reneging = 0;
1118 scoreboard_remove_hole (sb, hole);
1121 /* Partial 'head' overlap */
1124 if (seq_gt (blk->end, hole->start))
1126 hole->start = blk->end;
1133 /* Hole must be split */
1134 if (seq_lt (blk->end, hole->end))
1136 u32 hole_index = scoreboard_hole_index (sb, hole);
1137 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1139 /* Pool might've moved */
1140 hole = scoreboard_get_hole (sb, hole_index);
1141 hole->end = blk->start;
1143 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1145 else if (seq_lt (blk->start, hole->end))
1147 hole->end = blk->start;
1149 hole = scoreboard_next_hole (sb, hole);
1153 scoreboard_update_bytes (sb, ack, tc->snd_mss);
1155 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1156 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1157 || sb->sacked_bytes <= tc->snd_nxt - seq_max (tc->snd_una, ack));
1158 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1159 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1160 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1161 || sb->is_reneging || sb->holes[sb->head].start == ack);
1162 ASSERT (sb->last_lost_bytes <= sb->lost_bytes);
1164 TCP_EVT (TCP_EVT_CC_SCOREBOARD, tc);
1166 #endif /* CLIB_MARCH_VARIANT */
1169 * Try to update snd_wnd based on feedback received from peer.
1171 * If successful, and new window is 'effectively' 0, activate persist
1175 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1177 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1178 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1179 if (seq_lt (tc->snd_wl1, seq)
1180 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1182 tc->snd_wnd = snd_wnd;
1185 TCP_EVT (TCP_EVT_SND_WND, tc);
1187 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1189 /* Set persist timer if not set and we just got 0 wnd */
1190 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1191 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1192 tcp_persist_timer_set (tc);
1196 tcp_persist_timer_reset (tc);
1197 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1200 tcp_update_rto (tc);
1206 #ifndef CLIB_MARCH_VARIANT
1208 * Init loss recovery/fast recovery.
1210 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1211 * updated in @ref tcp_cc_handle_event after fast retransmit
1214 tcp_cc_init_congestion (tcp_connection_t * tc)
1216 tcp_fastrecovery_on (tc);
1217 tc->snd_congestion = tc->snd_nxt;
1218 tc->cwnd_acc_bytes = 0;
1219 tc->snd_rxt_bytes = 0;
1220 tc->prev_ssthresh = tc->ssthresh;
1221 tc->prev_cwnd = tc->cwnd;
1222 tc->cc_algo->congestion (tc);
1223 tc->fr_occurences += 1;
1224 TCP_EVT (TCP_EVT_CC_EVT, tc, 4);
1226 #endif /* CLIB_MARCH_VARIANT */
1229 tcp_cc_recovery_exit (tcp_connection_t * tc)
1232 tcp_update_rto (tc);
1235 tcp_recovery_off (tc);
1236 TCP_EVT (TCP_EVT_CC_EVT, tc, 3);
1239 #ifndef CLIB_MARCH_VARIANT
1241 tcp_cc_fastrecovery_clear (tcp_connection_t * tc)
1243 tc->snd_rxt_bytes = 0;
1244 tc->rcv_dupacks = 0;
1247 tcp_fastrecovery_off (tc);
1248 tcp_fastrecovery_first_off (tc);
1249 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1251 TCP_EVT (TCP_EVT_CC_EVT, tc, 3);
1253 #endif /* CLIB_MARCH_VARIANT */
1256 tcp_cc_congestion_undo (tcp_connection_t * tc)
1258 tc->cwnd = tc->prev_cwnd;
1259 tc->ssthresh = tc->prev_ssthresh;
1260 tc->rcv_dupacks = 0;
1261 if (tcp_in_recovery (tc))
1263 tcp_cc_recovery_exit (tc);
1264 tc->snd_nxt = seq_max (tc->snd_nxt, tc->snd_congestion);
1266 else if (tcp_in_fastrecovery (tc))
1268 tcp_cc_fastrecovery_clear (tc);
1270 tcp_cc_undo_recovery (tc);
1271 ASSERT (tc->rto_boff == 0);
1272 TCP_EVT (TCP_EVT_CC_EVT, tc, 5);
1276 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1278 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1280 && tcp_opts_tstamp (&tc->rcv_opts)
1281 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1285 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1287 return (tcp_in_fastrecovery (tc)
1288 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1292 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1294 return (tcp_cc_is_spurious_timeout_rxt (tc)
1295 || tcp_cc_is_spurious_fast_rxt (tc));
1299 tcp_cc_recover (tcp_connection_t * tc)
1301 ASSERT (tcp_in_cong_recovery (tc));
1302 if (tcp_cc_is_spurious_retransmit (tc))
1304 tcp_cc_congestion_undo (tc);
1308 if (tcp_in_recovery (tc))
1309 tcp_cc_recovery_exit (tc);
1310 else if (tcp_in_fastrecovery (tc))
1312 tcp_cc_recovered (tc);
1313 tcp_cc_fastrecovery_clear (tc);
1316 ASSERT (tc->rto_boff == 0);
1317 ASSERT (!tcp_in_cong_recovery (tc));
1318 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1323 tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1325 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1327 /* Congestion avoidance */
1328 tcp_cc_rcv_ack (tc, rs);
1330 /* If a cumulative ack, make sure dupacks is 0 */
1331 tc->rcv_dupacks = 0;
1333 /* When dupacks hits the threshold we only enter fast retransmit if
1334 * cumulative ack covers more than snd_congestion. Should snd_una
1335 * wrap this test may fail under otherwise valid circumstances.
1336 * Therefore, proactively update snd_congestion when wrap detected. */
1338 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1339 && seq_gt (tc->snd_congestion, tc->snd_una)))
1340 tc->snd_congestion = tc->snd_una - 1;
1344 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1346 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1350 tcp_should_fastrecover (tcp_connection_t * tc)
1352 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1353 || tcp_should_fastrecover_sack (tc));
1357 * One function to rule them all ... and in the darkness bind them
1360 tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs,
1365 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1367 if (tc->bytes_acked)
1369 tcp_program_fastretransmit (tc);
1373 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1374 * it account for the bytes that left the network.
1376 else if (is_dack && !tcp_in_recovery (tc))
1378 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1379 ASSERT (tc->snd_una != tc->snd_nxt || tc->sack_sb.last_sacked_bytes);
1383 /* Pure duplicate ack. If some data got acked, it's handled lower */
1384 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1386 ASSERT (tcp_in_fastrecovery (tc));
1387 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1390 else if (tcp_should_fastrecover (tc))
1394 ASSERT (!tcp_in_fastrecovery (tc));
1396 /* Heuristic to catch potential late dupacks
1397 * after fast retransmit exits */
1398 if (is_dack && tc->snd_una == tc->snd_congestion
1399 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1401 tc->rcv_dupacks = 0;
1405 tcp_cc_init_congestion (tc);
1407 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1408 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1410 /* Constrain rate until we get a partial ack */
1411 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1412 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1413 0 /* start bucket */ );
1414 tcp_program_fastretransmit (tc);
1417 else if (!tc->bytes_acked
1418 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1420 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1426 /* Don't allow entry in fast recovery if still in recovery, for now */
1427 else if (0 && is_dack && tcp_in_recovery (tc))
1429 /* If of of the two conditions lower hold, reset dupacks because
1430 * we're probably after timeout (RFC6582 heuristics).
1431 * If Cumulative ack does not cover more than congestion threshold,
1433 * 1) The following doesn't hold: The congestion window is greater
1434 * than SMSS bytes and the difference between highest_ack
1435 * and prev_highest_ack is at most 4*SMSS bytes
1436 * 2) Echoed timestamp in the last non-dup ack does not equal the
1439 if (seq_leq (tc->snd_una, tc->snd_congestion)
1440 && ((!(tc->cwnd > tc->snd_mss
1441 && tc->bytes_acked <= 4 * tc->snd_mss))
1442 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1444 tc->rcv_dupacks = 0;
1449 if (!tc->bytes_acked)
1453 TCP_EVT (TCP_EVT_CC_PACK, tc);
1456 * Legitimate ACK. 1) See if we can exit recovery
1459 /* Update the pacing rate. For the first partial ack we move from
1460 * the artificially constrained rate to the one after congestion */
1461 tcp_connection_tx_pacer_update (tc);
1463 if (seq_geq (tc->snd_una, tc->snd_congestion))
1465 tcp_retransmit_timer_update (tc);
1467 /* If spurious return, we've already updated everything */
1468 if (tcp_cc_recover (tc))
1470 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1474 /* Treat as congestion avoidance ack */
1475 tcp_cc_rcv_ack (tc, rs);
1480 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1483 /* XXX limit this only to first partial ack? */
1484 tcp_retransmit_timer_update (tc);
1486 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1487 * reset dupacks to 0. Also needed if in congestion recovery */
1488 tc->rcv_dupacks = 0;
1490 /* Post RTO timeout don't try anything fancy */
1491 if (tcp_in_recovery (tc))
1493 tcp_cc_rcv_ack (tc, rs);
1494 transport_add_tx_event (&tc->connection);
1498 /* Remove retransmitted bytes that have been delivered */
1499 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1501 ASSERT (tc->bytes_acked >= tc->sack_sb.last_bytes_delivered
1502 || (tc->flags & TCP_CONN_FINSNT));
1504 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1505 * remove sacked bytes delivered */
1506 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1508 rxt_delivered = tc->bytes_acked - tc->sack_sb.last_bytes_delivered;
1509 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1510 tc->snd_rxt_bytes -= rxt_delivered;
1514 /* Apparently all retransmitted holes have been acked */
1515 tc->snd_rxt_bytes = 0;
1516 tc->sack_sb.high_rxt = tc->snd_una;
1521 tcp_fastrecovery_first_on (tc);
1522 if (tc->snd_rxt_bytes > tc->bytes_acked)
1523 tc->snd_rxt_bytes -= tc->bytes_acked;
1525 tc->snd_rxt_bytes = 0;
1528 tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs);
1531 * Since this was a partial ack, try to retransmit some more data
1533 tcp_program_fastretransmit (tc);
1537 * Process incoming ACK
1540 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1541 tcp_header_t * th, u32 * error)
1543 u32 prev_snd_wnd, prev_snd_una;
1544 tcp_rate_sample_t rs = { 0 };
1547 TCP_EVT (TCP_EVT_CC_STAT, tc);
1549 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1550 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1552 /* We've probably entered recovery and the peer still has some
1553 * of the data we've sent. Update snd_nxt and accept the ack */
1554 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1555 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1557 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1561 tc->errors.above_ack_wnd += 1;
1562 *error = TCP_ERROR_ACK_FUTURE;
1563 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 0, vnet_buffer (b)->tcp.ack_number);
1567 /* If old ACK, probably it's an old dupack */
1568 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1570 tc->errors.below_ack_wnd += 1;
1571 *error = TCP_ERROR_ACK_OLD;
1572 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 1, vnet_buffer (b)->tcp.ack_number);
1573 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1574 tcp_cc_handle_event (tc, 0, 1);
1575 /* Don't drop yet */
1582 * Looks okay, process feedback
1585 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1586 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1588 prev_snd_wnd = tc->snd_wnd;
1589 prev_snd_una = tc->snd_una;
1590 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1591 vnet_buffer (b)->tcp.ack_number,
1592 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1593 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1594 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
1595 tcp_validate_txf_size (tc, tc->bytes_acked);
1597 if (tc->bytes_acked)
1599 tcp_program_dequeue (wrk, tc);
1600 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1603 if (tc->flags & TCP_CONN_RATE_SAMPLE)
1604 tcp_bt_sample_delivery_rate (tc, &rs);
1606 TCP_EVT (TCP_EVT_ACK_RCVD, tc);
1609 * Check if we have congestion event
1612 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1614 tcp_cc_handle_event (tc, &rs, is_dack);
1615 tc->dupacks_in += is_dack;
1616 if (!tcp_in_cong_recovery (tc))
1618 *error = TCP_ERROR_ACK_OK;
1621 *error = TCP_ERROR_ACK_DUP;
1622 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1628 * Update congestion control (slow start/congestion avoidance)
1630 tcp_cc_update (tc, &rs);
1631 *error = TCP_ERROR_ACK_OK;
1636 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1638 if (!tcp_disconnect_pending (tc))
1640 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1641 tcp_disconnect_pending_on (tc);
1646 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1648 u32 thread_index, *pending_disconnects;
1649 tcp_connection_t *tc;
1652 if (!vec_len (wrk->pending_disconnects))
1655 thread_index = wrk->vm->thread_index;
1656 pending_disconnects = wrk->pending_disconnects;
1657 for (i = 0; i < vec_len (pending_disconnects); i++)
1659 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1660 tcp_disconnect_pending_off (tc);
1661 session_transport_closing_notify (&tc->connection);
1663 _vec_len (wrk->pending_disconnects) = 0;
1667 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1670 /* Reject out-of-order fins */
1671 if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt)
1674 /* Account for the FIN and send ack */
1676 tcp_program_ack (tc);
1677 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1678 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1679 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1680 tcp_program_disconnect (wrk, tc);
1681 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
1682 TCP_EVT (TCP_EVT_FIN_RCVD, tc);
1683 *error = TCP_ERROR_FIN_RCVD;
1686 #ifndef CLIB_MARCH_VARIANT
1688 tcp_sack_vector_is_sane (sack_block_t * sacks)
1691 for (i = 1; i < vec_len (sacks); i++)
1693 if (sacks[i - 1].end == sacks[i].start)
1700 * Build SACK list as per RFC2018.
1702 * Makes sure the first block contains the segment that generated the current
1703 * ACK and the following ones are the ones most recently reported in SACK
1706 * @param tc TCP connection for which the SACK list is updated
1707 * @param start Start sequence number of the newest SACK block
1708 * @param end End sequence of the newest SACK block
1711 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1713 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1716 /* If the first segment is ooo add it to the list. Last write might've moved
1717 * rcv_nxt over the first segment. */
1718 if (seq_lt (tc->rcv_nxt, start))
1720 vec_add2 (new_list, block, 1);
1721 block->start = start;
1725 /* Find the blocks still worth keeping. */
1726 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1728 /* Discard if rcv_nxt advanced beyond current block */
1729 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1732 /* Merge or drop if segment overlapped by the new segment */
1733 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1734 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1736 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1737 new_list[0].start = tc->snd_sacks[i].start;
1738 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1739 new_list[0].end = tc->snd_sacks[i].end;
1743 /* Save to new SACK list if we have space. */
1744 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1745 vec_add1 (new_list, tc->snd_sacks[i]);
1748 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1750 /* Replace old vector with new one */
1751 vec_reset_length (tc->snd_sacks);
1752 tc->snd_sacks_fl = tc->snd_sacks;
1753 tc->snd_sacks = new_list;
1755 /* Segments should not 'touch' */
1756 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1760 tcp_sack_list_bytes (tcp_connection_t * tc)
1763 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1764 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1767 #endif /* CLIB_MARCH_VARIANT */
1769 /** Enqueue data for delivery to application */
1771 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1774 int written, error = TCP_ERROR_ENQUEUED;
1776 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1778 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1779 1 /* queue event */ , 1);
1780 tc->bytes_in += written;
1782 TCP_EVT (TCP_EVT_INPUT, tc, 0, data_len, written);
1784 /* Update rcv_nxt */
1785 if (PREDICT_TRUE (written == data_len))
1787 tc->rcv_nxt += written;
1789 /* If more data written than expected, account for out-of-order bytes. */
1790 else if (written > data_len)
1792 tc->rcv_nxt += written;
1793 TCP_EVT (TCP_EVT_CC_INPUT, tc, data_len, written);
1795 else if (written > 0)
1797 /* We've written something but FIFO is probably full now */
1798 tc->rcv_nxt += written;
1799 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1803 return TCP_ERROR_FIFO_FULL;
1806 /* Update SACK list if need be */
1807 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1809 /* Remove SACK blocks that have been delivered */
1810 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1816 /** Enqueue out-of-order data */
1818 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1824 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1827 /* Enqueue out-of-order data with relative offset */
1828 rv = session_enqueue_stream_connection (&tc->connection, b,
1829 vnet_buffer (b)->tcp.seq_number -
1830 tc->rcv_nxt, 0 /* queue event */ ,
1833 /* Nothing written */
1836 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, 0);
1837 return TCP_ERROR_FIFO_FULL;
1840 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1841 tc->bytes_in += data_len;
1843 /* Update SACK list if in use */
1844 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1846 ooo_segment_t *newest;
1849 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1851 /* Get the newest segment from the fifo */
1852 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1855 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1856 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1857 start = tc->rcv_nxt + offset;
1858 end = start + ooo_segment_length (s0->rx_fifo, newest);
1859 tcp_update_sack_list (tc, start, end);
1860 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1861 TCP_EVT (TCP_EVT_CC_SACKS, tc);
1865 return TCP_ERROR_ENQUEUED_OOO;
1869 * Check if ACK could be delayed. If ack can be delayed, it should return
1870 * true for a full frame. If we're always acking return 0.
1873 tcp_can_delack (tcp_connection_t * tc)
1875 /* Send ack if ... */
1877 /* just sent a rcv wnd 0
1878 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1879 /* constrained to send ack */
1880 || (tc->flags & TCP_CONN_SNDACK) != 0
1881 /* we're almost out of tx wnd */
1882 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1889 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1891 u32 discard, first = b->current_length;
1892 vlib_main_t *vm = vlib_get_main ();
1894 /* Handle multi-buffer segments */
1895 if (n_bytes_to_drop > b->current_length)
1897 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1901 discard = clib_min (n_bytes_to_drop, b->current_length);
1902 vlib_buffer_advance (b, discard);
1903 b = vlib_get_buffer (vm, b->next_buffer);
1904 n_bytes_to_drop -= discard;
1906 while (n_bytes_to_drop);
1907 if (n_bytes_to_drop > first)
1908 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1911 vlib_buffer_advance (b, n_bytes_to_drop);
1912 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1917 * Receive buffer for connection and handle acks
1919 * It handles both in order or out-of-order data.
1922 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1925 u32 error, n_bytes_to_drop, n_data_bytes;
1927 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1928 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1929 ASSERT (n_data_bytes);
1930 tc->data_segs_in += 1;
1932 /* Handle out-of-order data */
1933 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1935 /* Old sequence numbers allowed through because they overlapped
1937 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1939 /* Completely in the past (possible retransmit). Ack
1940 * retransmissions since we may not have any data to send */
1941 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1943 tcp_program_ack (tc);
1944 error = TCP_ERROR_SEGMENT_OLD;
1948 /* Chop off the bytes in the past and see if what is left
1949 * can be enqueued in order */
1950 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1951 n_data_bytes -= n_bytes_to_drop;
1952 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1953 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1955 error = TCP_ERROR_SEGMENT_OLD;
1961 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1962 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1963 tcp_program_dupack (tc);
1964 TCP_EVT (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1965 tc->errors.above_data_wnd += seq_gt (vnet_buffer (b)->tcp.seq_end,
1966 tc->rcv_las + tc->rcv_wnd);
1972 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1973 * segments can be enqueued after fifo tail offset changes. */
1974 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1975 if (tcp_can_delack (tc))
1977 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1978 tcp_timer_set (tc, TCP_TIMER_DELACK, tcp_cfg.delack_time);
1982 tcp_program_ack (tc);
1990 tcp_header_t tcp_header;
1991 tcp_connection_t tcp_connection;
1995 format_tcp_rx_trace (u8 * s, va_list * args)
1997 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1998 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1999 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2000 u32 indent = format_get_indent (s);
2002 s = format (s, "%U\n%U%U",
2003 format_tcp_header, &t->tcp_header, 128,
2004 format_white_space, indent,
2005 format_tcp_connection, &t->tcp_connection, 1);
2011 format_tcp_rx_trace_short (u8 * s, va_list * args)
2013 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2014 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2015 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2017 s = format (s, "%d -> %d (%U)",
2018 clib_net_to_host_u16 (t->tcp_header.dst_port),
2019 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2020 t->tcp_connection.state);
2026 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2027 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2031 clib_memcpy_fast (&t0->tcp_connection, tc0,
2032 sizeof (t0->tcp_connection));
2036 th0 = tcp_buffer_hdr (b0);
2038 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2042 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2043 vlib_frame_t * frame, u8 is_ip4)
2047 n_left = frame->n_vectors;
2048 from = vlib_frame_vector_args (frame);
2052 tcp_connection_t *tc0;
2059 b0 = vlib_get_buffer (vm, bi0);
2061 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2063 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2064 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2066 th0 = tcp_buffer_hdr (b0);
2067 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2076 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2077 u8 is_ip4, u32 evt, u32 val)
2080 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2082 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2085 #define tcp_maybe_inc_counter(node_id, err, count) \
2087 if (next0 != tcp_next_drop (is_ip4)) \
2088 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2089 tcp6_##node_id##_node.index, is_ip4, err, \
2092 #define tcp_inc_counter(node_id, err, count) \
2093 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2094 tcp6_##node_id##_node.index, is_ip4, \
2096 #define tcp_maybe_inc_err_counter(cnts, err) \
2098 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2100 #define tcp_inc_err_counter(cnts, err, val) \
2104 #define tcp_store_err_counters(node_id, cnts) \
2107 for (i = 0; i < TCP_N_ERROR; i++) \
2109 tcp_inc_counter(node_id, i, cnts[i]); \
2114 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2115 vlib_frame_t * frame, int is_ip4)
2117 u32 thread_index = vm->thread_index, errors = 0;
2118 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2119 u32 n_left_from, *from, *first_buffer;
2120 u16 err_counters[TCP_N_ERROR] = { 0 };
2122 if (node->flags & VLIB_NODE_FLAG_TRACE)
2123 tcp_established_trace_frame (vm, node, frame, is_ip4);
2125 first_buffer = from = vlib_frame_vector_args (frame);
2126 n_left_from = frame->n_vectors;
2128 while (n_left_from > 0)
2130 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2133 tcp_connection_t *tc0;
2135 if (n_left_from > 1)
2138 pb = vlib_get_buffer (vm, from[1]);
2139 vlib_prefetch_buffer_header (pb, LOAD);
2140 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2147 b0 = vlib_get_buffer (vm, bi0);
2148 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2151 if (PREDICT_FALSE (tc0 == 0))
2153 error0 = TCP_ERROR_INVALID_CONNECTION;
2157 th0 = tcp_buffer_hdr (b0);
2159 /* TODO header prediction fast path */
2161 /* 1-4: check SEQ, RST, SYN */
2162 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2164 TCP_EVT (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2168 /* 5: check the ACK field */
2169 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2172 /* 6: check the URG bit TODO */
2174 /* 7: process the segment text */
2175 if (vnet_buffer (b0)->tcp.data_len)
2176 error0 = tcp_segment_rcv (wrk, tc0, b0);
2178 /* 8: check the FIN bit */
2179 if (PREDICT_FALSE (tcp_is_fin (th0)))
2180 tcp_rcv_fin (wrk, tc0, b0, &error0);
2183 tcp_inc_err_counter (err_counters, error0, 1);
2186 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2188 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2189 tcp_store_err_counters (established, err_counters);
2190 tcp_handle_postponed_dequeues (wrk);
2191 tcp_handle_disconnects (wrk);
2192 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2194 return frame->n_vectors;
2197 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2198 vlib_node_runtime_t * node,
2199 vlib_frame_t * from_frame)
2201 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2204 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2205 vlib_node_runtime_t * node,
2206 vlib_frame_t * from_frame)
2208 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2212 VLIB_REGISTER_NODE (tcp4_established_node) =
2214 .name = "tcp4-established",
2215 /* Takes a vector of packets. */
2216 .vector_size = sizeof (u32),
2217 .n_errors = TCP_N_ERROR,
2218 .error_strings = tcp_error_strings,
2219 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2222 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2223 foreach_tcp_state_next
2226 .format_trace = format_tcp_rx_trace_short,
2231 VLIB_REGISTER_NODE (tcp6_established_node) =
2233 .name = "tcp6-established",
2234 /* Takes a vector of packets. */
2235 .vector_size = sizeof (u32),
2236 .n_errors = TCP_N_ERROR,
2237 .error_strings = tcp_error_strings,
2238 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2241 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2242 foreach_tcp_state_next
2245 .format_trace = format_tcp_rx_trace_short,
2251 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2253 transport_connection_t *tmp = 0;
2260 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2263 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2264 && (tc->state == TCP_STATE_LISTEN
2265 || tc->c_rmt_port == hdr->src_port));
2269 handle = session_lookup_half_open_handle (&tc->connection);
2270 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2271 tc->c_proto, tc->c_is_ip4);
2275 if (tmp->lcl_port == hdr->dst_port
2276 && tmp->rmt_port == hdr->src_port)
2278 TCP_DBG ("half-open is valid!");
2286 * Lookup transport connection
2288 static tcp_connection_t *
2289 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2293 transport_connection_t *tconn;
2294 tcp_connection_t *tc;
2299 ip4 = vlib_buffer_get_current (b);
2300 tcp = ip4_next_header (ip4);
2301 tconn = session_lookup_connection_wt4 (fib_index,
2306 TRANSPORT_PROTO_TCP,
2307 thread_index, &is_filtered);
2308 tc = tcp_get_connection_from_transport (tconn);
2309 ASSERT (tcp_lookup_is_valid (tc, tcp));
2314 ip6 = vlib_buffer_get_current (b);
2315 tcp = ip6_next_header (ip6);
2316 tconn = session_lookup_connection_wt6 (fib_index,
2321 TRANSPORT_PROTO_TCP,
2322 thread_index, &is_filtered);
2323 tc = tcp_get_connection_from_transport (tconn);
2324 ASSERT (tcp_lookup_is_valid (tc, tcp));
2330 tcp_check_tx_offload (tcp_connection_t * tc, int is_ipv4)
2332 vnet_main_t *vnm = vnet_get_main ();
2333 const dpo_id_t *dpo;
2334 const load_balance_t *lb;
2335 vnet_hw_interface_t *hw_if;
2336 u32 sw_if_idx, lb_idx;
2340 ip4_address_t *dst_addr = &(tc->c_rmt_ip.ip4);
2341 lb_idx = ip4_fib_forwarding_lookup (tc->c_fib_index, dst_addr);
2345 ip6_address_t *dst_addr = &(tc->c_rmt_ip.ip6);
2346 lb_idx = ip6_fib_table_fwding_lookup (tc->c_fib_index, dst_addr);
2349 lb = load_balance_get (lb_idx);
2350 dpo = load_balance_get_bucket_i (lb, 0);
2352 sw_if_idx = dpo->dpoi_index;
2353 hw_if = vnet_get_sup_hw_interface (vnm, sw_if_idx);
2356 ((hw_if->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO) == 0) ? 0 : 1;
2361 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2362 vlib_frame_t * from_frame, int is_ip4)
2364 u32 n_left_from, *from, *first_buffer, errors = 0;
2365 u32 my_thread_index = vm->thread_index;
2366 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2368 from = first_buffer = vlib_frame_vector_args (from_frame);
2369 n_left_from = from_frame->n_vectors;
2371 while (n_left_from > 0)
2373 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2374 tcp_connection_t *tc0, *new_tc0;
2375 tcp_header_t *tcp0 = 0;
2383 b0 = vlib_get_buffer (vm, bi0);
2385 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2386 if (PREDICT_FALSE (tc0 == 0))
2388 error0 = TCP_ERROR_INVALID_CONNECTION;
2392 /* Half-open completed recently but the connection was't removed
2393 * yet by the owning thread */
2394 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2396 /* Make sure the connection actually exists */
2397 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2398 my_thread_index, is_ip4));
2399 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2403 ack0 = vnet_buffer (b0)->tcp.ack_number;
2404 seq0 = vnet_buffer (b0)->tcp.seq_number;
2405 tcp0 = tcp_buffer_hdr (b0);
2407 /* Crude check to see if the connection handle does not match
2408 * the packet. Probably connection just switched to established */
2409 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2410 || tcp0->src_port != tc0->c_rmt_port))
2412 error0 = TCP_ERROR_INVALID_CONNECTION;
2416 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2417 && !tcp_syn (tcp0)))
2419 error0 = TCP_ERROR_SEGMENT_INVALID;
2423 /* SYNs consume sequence numbers */
2424 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2427 * 1. check the ACK bit
2431 * If the ACK bit is set
2432 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2433 * the RST bit is set, if so drop the segment and return)
2434 * <SEQ=SEG.ACK><CTL=RST>
2435 * and discard the segment. Return.
2436 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2440 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2442 if (!tcp_rst (tcp0))
2443 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2444 error0 = TCP_ERROR_RCV_WND;
2448 /* Make sure ACK is valid */
2449 if (seq_gt (tc0->snd_una, ack0))
2451 error0 = TCP_ERROR_ACK_INVALID;
2457 * 2. check the RST bit
2462 /* If ACK is acceptable, signal client that peer is not
2463 * willing to accept connection and drop connection*/
2465 tcp_connection_reset (tc0);
2466 error0 = TCP_ERROR_RST_RCVD;
2471 * 3. check the security and precedence (skipped)
2475 * 4. check the SYN bit
2478 /* No SYN flag. Drop. */
2479 if (!tcp_syn (tcp0))
2481 error0 = TCP_ERROR_SEGMENT_INVALID;
2486 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2488 error0 = TCP_ERROR_OPTIONS;
2492 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2493 * current thread pool. */
2494 new_tc0 = tcp_connection_alloc_w_base (my_thread_index, tc0);
2495 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2496 new_tc0->irs = seq0;
2497 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2498 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2500 /* If this is not the owning thread, wait for syn retransmit to
2501 * expire and cleanup then */
2502 if (tcp_half_open_connection_cleanup (tc0))
2503 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2505 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2507 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2508 new_tc0->tsval_recent_age = tcp_time_now ();
2511 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2512 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2514 new_tc0->rcv_wscale = 0;
2516 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2517 << new_tc0->snd_wscale;
2518 new_tc0->snd_wl1 = seq0;
2519 new_tc0->snd_wl2 = ack0;
2521 tcp_connection_init_vars (new_tc0);
2523 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2524 if (PREDICT_TRUE (tcp_ack (tcp0)))
2526 /* Our SYN is ACKed: we have iss < ack = snd_una */
2528 /* TODO Dequeue acknowledged segments if we support Fast Open */
2529 new_tc0->snd_una = ack0;
2530 new_tc0->state = TCP_STATE_ESTABLISHED;
2532 /* Make sure las is initialized for the wnd computation */
2533 new_tc0->rcv_las = new_tc0->rcv_nxt;
2535 /* Notify app that we have connection. If session layer can't
2536 * allocate session send reset */
2537 if (session_stream_connect_notify (&new_tc0->connection, 0))
2539 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2540 tcp_connection_cleanup (new_tc0);
2541 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2545 new_tc0->tx_fifo_size =
2546 transport_tx_fifo_size (&new_tc0->connection);
2547 /* Update rtt with the syn-ack sample */
2548 tcp_estimate_initial_rtt (new_tc0);
2549 TCP_EVT (TCP_EVT_SYNACK_RCVD, new_tc0);
2550 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2552 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2555 new_tc0->state = TCP_STATE_SYN_RCVD;
2557 /* Notify app that we have connection */
2558 if (session_stream_connect_notify (&new_tc0->connection, 0))
2560 tcp_connection_cleanup (new_tc0);
2561 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2562 TCP_EVT (TCP_EVT_RST_SENT, tc0);
2563 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2567 new_tc0->tx_fifo_size =
2568 transport_tx_fifo_size (&new_tc0->connection);
2569 new_tc0->rtt_ts = 0;
2570 tcp_init_snd_vars (new_tc0);
2571 tcp_send_synack (new_tc0);
2572 error0 = TCP_ERROR_SYNS_RCVD;
2576 tcp_check_tx_offload (new_tc0, is_ip4);
2578 /* Read data, if any */
2579 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2581 clib_warning ("rcvd data in syn-sent");
2582 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2583 if (error0 == TCP_ERROR_ACK_OK)
2584 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2588 tcp_program_ack (new_tc0);
2593 tcp_inc_counter (syn_sent, error0, 1);
2594 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2596 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2597 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2598 clib_memcpy_fast (&t0->tcp_connection, tc0,
2599 sizeof (t0->tcp_connection));
2603 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2605 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2606 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2608 return from_frame->n_vectors;
2611 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2612 vlib_node_runtime_t * node,
2613 vlib_frame_t * from_frame)
2615 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2618 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2619 vlib_node_runtime_t * node,
2620 vlib_frame_t * from_frame)
2622 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2626 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2628 .name = "tcp4-syn-sent",
2629 /* Takes a vector of packets. */
2630 .vector_size = sizeof (u32),
2631 .n_errors = TCP_N_ERROR,
2632 .error_strings = tcp_error_strings,
2633 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2636 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2637 foreach_tcp_state_next
2640 .format_trace = format_tcp_rx_trace_short,
2645 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2647 .name = "tcp6-syn-sent",
2648 /* Takes a vector of packets. */
2649 .vector_size = sizeof (u32),
2650 .n_errors = TCP_N_ERROR,
2651 .error_strings = tcp_error_strings,
2652 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2655 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2656 foreach_tcp_state_next
2659 .format_trace = format_tcp_rx_trace_short,
2664 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2665 * as per RFC793 p. 64
2668 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2669 vlib_frame_t * from_frame, int is_ip4)
2671 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2672 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2673 u32 n_left_from, *from, max_dequeue;
2675 from = first_buffer = vlib_frame_vector_args (from_frame);
2676 n_left_from = from_frame->n_vectors;
2678 while (n_left_from > 0)
2680 u32 bi0, error0 = TCP_ERROR_NONE;
2681 tcp_header_t *tcp0 = 0;
2682 tcp_connection_t *tc0;
2690 b0 = vlib_get_buffer (vm, bi0);
2691 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2693 if (PREDICT_FALSE (tc0 == 0))
2695 error0 = TCP_ERROR_INVALID_CONNECTION;
2699 tcp0 = tcp_buffer_hdr (b0);
2700 is_fin0 = tcp_is_fin (tcp0);
2704 tcp_connection_t *tmp;
2705 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2707 if (tmp->state != tc0->state)
2709 if (tc0->state != TCP_STATE_CLOSED)
2710 clib_warning ("state changed");
2716 * Special treatment for CLOSED
2718 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2720 error0 = TCP_ERROR_CONNECTION_CLOSED;
2725 * For all other states (except LISTEN)
2728 /* 1-4: check SEQ, RST, SYN */
2729 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2732 /* 5: check the ACK field */
2735 case TCP_STATE_SYN_RCVD:
2737 /* Make sure the segment is exactly right */
2738 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2740 tcp_connection_reset (tc0);
2741 error0 = TCP_ERROR_SEGMENT_INVALID;
2746 * If the segment acknowledgment is not acceptable, form a
2748 * <SEQ=SEG.ACK><CTL=RST>
2751 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2753 tcp_connection_reset (tc0);
2757 /* Update rtt and rto */
2758 tcp_estimate_initial_rtt (tc0);
2760 /* Switch state to ESTABLISHED */
2761 tc0->state = TCP_STATE_ESTABLISHED;
2762 TCP_EVT (TCP_EVT_STATE_CHANGE, tc0);
2764 tcp_check_tx_offload (tc0, is_ip4);
2766 /* Initialize session variables */
2767 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2768 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2769 << tc0->rcv_opts.wscale;
2770 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2771 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2773 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2774 tcp_retransmit_timer_reset (tc0);
2775 if (session_stream_accept_notify (&tc0->connection))
2777 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2778 tcp_connection_reset (tc0);
2781 error0 = TCP_ERROR_ACK_OK;
2783 case TCP_STATE_ESTABLISHED:
2784 /* We can get packets in established state here because they
2785 * were enqueued before state change */
2786 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2790 case TCP_STATE_FIN_WAIT_1:
2791 /* In addition to the processing for the ESTABLISHED state, if
2792 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2793 * continue processing in that state. */
2794 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2797 /* Still have to send the FIN */
2798 if (tc0->flags & TCP_CONN_FINPNDG)
2800 /* TX fifo finally drained */
2801 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2802 if (max_dequeue <= tc0->burst_acked)
2804 /* If a fin was received and data was acked extend wait */
2805 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
2806 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2807 tcp_cfg.closewait_time);
2809 /* If FIN is ACKed */
2810 else if (tc0->snd_una == tc0->snd_nxt)
2812 /* Stop all retransmit timers because we have nothing more
2814 tcp_connection_timers_reset (tc0);
2816 /* We already have a FIN but didn't transition to CLOSING
2817 * because of outstanding tx data. Close the connection. */
2818 if (tc0->flags & TCP_CONN_FINRCVD)
2820 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2821 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE,
2822 tcp_cfg.cleanup_time);
2823 session_transport_closed_notify (&tc0->connection);
2827 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2828 /* Enable waitclose because we're willing to wait for peer's
2829 * FIN but not indefinitely. */
2830 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait2_time);
2832 /* Don't try to deq the FIN acked */
2833 if (tc0->burst_acked > 1)
2834 session_tx_fifo_dequeue_drop (&tc0->connection,
2835 tc0->burst_acked - 1);
2836 tc0->burst_acked = 0;
2839 case TCP_STATE_FIN_WAIT_2:
2840 /* In addition to the processing for the ESTABLISHED state, if
2841 * the retransmission queue is empty, the user's CLOSE can be
2842 * acknowledged ("ok") but do not delete the TCB. */
2843 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2845 tc0->burst_acked = 0;
2847 case TCP_STATE_CLOSE_WAIT:
2848 /* Do the same processing as for the ESTABLISHED state. */
2849 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2852 if (!(tc0->flags & TCP_CONN_FINPNDG))
2855 /* Still have outstanding tx data */
2856 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2857 if (max_dequeue > tc0->burst_acked)
2861 tcp_connection_timers_reset (tc0);
2862 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2863 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2865 case TCP_STATE_CLOSING:
2866 /* In addition to the processing for the ESTABLISHED state, if
2867 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2868 * otherwise ignore the segment. */
2869 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2872 if (tc0->snd_una != tc0->snd_nxt)
2875 tcp_connection_timers_reset (tc0);
2876 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2877 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2878 session_transport_closed_notify (&tc0->connection);
2882 case TCP_STATE_LAST_ACK:
2883 /* The only thing that [should] arrive in this state is an
2884 * acknowledgment of our FIN. If our FIN is now acknowledged,
2885 * delete the TCB, enter the CLOSED state, and return. */
2887 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2890 /* Apparently our ACK for the peer's FIN was lost */
2891 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2897 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2898 session_transport_closed_notify (&tc0->connection);
2900 /* Don't free the connection from the data path since
2901 * we can't ensure that we have no packets already enqueued
2902 * to output. Rely instead on the waitclose timer */
2903 tcp_connection_timers_reset (tc0);
2904 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
2909 case TCP_STATE_TIME_WAIT:
2910 /* The only thing that can arrive in this state is a
2911 * retransmission of the remote FIN. Acknowledge it, and restart
2912 * the 2 MSL timeout. */
2914 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2920 tcp_program_ack (tc0);
2921 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2929 /* 6: check the URG bit TODO */
2931 /* 7: process the segment text */
2934 case TCP_STATE_ESTABLISHED:
2935 case TCP_STATE_FIN_WAIT_1:
2936 case TCP_STATE_FIN_WAIT_2:
2937 if (vnet_buffer (b0)->tcp.data_len)
2938 error0 = tcp_segment_rcv (wrk, tc0, b0);
2940 case TCP_STATE_CLOSE_WAIT:
2941 case TCP_STATE_CLOSING:
2942 case TCP_STATE_LAST_ACK:
2943 case TCP_STATE_TIME_WAIT:
2944 /* This should not occur, since a FIN has been received from the
2945 * remote side. Ignore the segment text. */
2949 /* 8: check the FIN bit */
2953 TCP_EVT (TCP_EVT_FIN_RCVD, tc0);
2957 case TCP_STATE_ESTABLISHED:
2958 /* Account for the FIN and send ack */
2960 tcp_program_ack (tc0);
2961 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2962 tcp_program_disconnect (wrk, tc0);
2963 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
2965 case TCP_STATE_SYN_RCVD:
2966 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2967 * notified yet, set a cleanup timer instead of relying on
2968 * disconnect notify and the implicit close call. */
2969 tcp_connection_timers_reset (tc0);
2972 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2973 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2975 case TCP_STATE_CLOSE_WAIT:
2976 case TCP_STATE_CLOSING:
2977 case TCP_STATE_LAST_ACK:
2980 case TCP_STATE_FIN_WAIT_1:
2983 if (tc0->flags & TCP_CONN_FINPNDG)
2985 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
2986 * sending it. Since we already received a fin, do not wait
2988 tc0->flags |= TCP_CONN_FINRCVD;
2989 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2990 tcp_cfg.closewait_time);
2994 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
2995 tcp_program_ack (tc0);
2996 /* Wait for ACK for our FIN but not forever */
2997 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2998 tcp_cfg.closing_time);
3001 case TCP_STATE_FIN_WAIT_2:
3002 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
3004 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
3005 tcp_connection_timers_reset (tc0);
3006 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3007 tcp_program_ack (tc0);
3008 session_transport_closed_notify (&tc0->connection);
3010 case TCP_STATE_TIME_WAIT:
3011 /* Remain in the TIME-WAIT state. Restart the time-wait
3014 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3017 error0 = TCP_ERROR_FIN_RCVD;
3021 tcp_inc_counter (rcv_process, error0, 1);
3022 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3024 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3025 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3029 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
3031 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3032 tcp_handle_postponed_dequeues (wrk);
3033 tcp_handle_disconnects (wrk);
3034 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3036 return from_frame->n_vectors;
3039 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
3040 vlib_node_runtime_t * node,
3041 vlib_frame_t * from_frame)
3043 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3046 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
3047 vlib_node_runtime_t * node,
3048 vlib_frame_t * from_frame)
3050 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3054 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3056 .name = "tcp4-rcv-process",
3057 /* Takes a vector of packets. */
3058 .vector_size = sizeof (u32),
3059 .n_errors = TCP_N_ERROR,
3060 .error_strings = tcp_error_strings,
3061 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3064 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3065 foreach_tcp_state_next
3068 .format_trace = format_tcp_rx_trace_short,
3073 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3075 .name = "tcp6-rcv-process",
3076 /* Takes a vector of packets. */
3077 .vector_size = sizeof (u32),
3078 .n_errors = TCP_N_ERROR,
3079 .error_strings = tcp_error_strings,
3080 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3083 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3084 foreach_tcp_state_next
3087 .format_trace = format_tcp_rx_trace_short,
3092 * LISTEN state processing as per RFC 793 p. 65
3095 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3096 vlib_frame_t * from_frame, int is_ip4)
3098 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3099 u32 my_thread_index = vm->thread_index;
3101 from = first_buffer = vlib_frame_vector_args (from_frame);
3102 n_left_from = from_frame->n_vectors;
3104 while (n_left_from > 0)
3109 tcp_header_t *th0 = 0;
3110 tcp_connection_t *lc0;
3113 tcp_connection_t *child0;
3114 u32 error0 = TCP_ERROR_NONE;
3120 b0 = vlib_get_buffer (vm, bi0);
3121 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3125 ip40 = vlib_buffer_get_current (b0);
3126 th0 = ip4_next_header (ip40);
3130 ip60 = vlib_buffer_get_current (b0);
3131 th0 = ip6_next_header (ip60);
3134 /* Create child session. For syn-flood protection use filter */
3136 /* 1. first check for an RST: handled in dispatch */
3137 /* if (tcp_rst (th0))
3141 /* 2. second check for an ACK: handled in dispatch */
3142 /* if (tcp_ack (th0))
3144 tcp_send_reset (b0, is_ip4);
3149 /* 3. check for a SYN (did that already) */
3151 /* Make sure connection wasn't just created */
3152 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3154 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3156 error0 = TCP_ERROR_CREATE_EXISTS;
3160 /* Create child session and send SYN-ACK */
3161 child0 = tcp_connection_alloc (my_thread_index);
3162 child0->c_lcl_port = th0->dst_port;
3163 child0->c_rmt_port = th0->src_port;
3164 child0->c_is_ip4 = is_ip4;
3165 child0->state = TCP_STATE_SYN_RCVD;
3166 child0->c_fib_index = lc0->c_fib_index;
3167 child0->cc_algo = lc0->cc_algo;
3171 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3172 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3176 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3177 sizeof (ip6_address_t));
3178 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3179 sizeof (ip6_address_t));
3182 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3184 error0 = TCP_ERROR_OPTIONS;
3185 tcp_connection_free (child0);
3189 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3190 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3191 child0->rcv_las = child0->rcv_nxt;
3192 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3194 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3195 * segments are used to initialize PAWS. */
3196 if (tcp_opts_tstamp (&child0->rcv_opts))
3198 child0->tsval_recent = child0->rcv_opts.tsval;
3199 child0->tsval_recent_age = tcp_time_now ();
3202 if (tcp_opts_wscale (&child0->rcv_opts))
3203 child0->snd_wscale = child0->rcv_opts.wscale;
3205 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3206 << child0->snd_wscale;
3207 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3208 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3210 tcp_connection_init_vars (child0);
3211 child0->rto = TCP_RTO_MIN;
3213 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3214 lc0->c_thread_index, 0 /* notify */ ))
3216 tcp_connection_cleanup (child0);
3217 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3221 TCP_EVT (TCP_EVT_SYN_RCVD, child0, 1);
3222 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3223 tcp_send_synack (child0);
3227 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3229 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3230 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3231 clib_memcpy_fast (&t0->tcp_connection, lc0,
3232 sizeof (t0->tcp_connection));
3235 n_syns += (error0 == TCP_ERROR_NONE);
3238 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3239 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3241 return from_frame->n_vectors;
3244 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3245 vlib_frame_t * from_frame)
3247 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3250 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3251 vlib_frame_t * from_frame)
3253 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3257 VLIB_REGISTER_NODE (tcp4_listen_node) =
3259 .name = "tcp4-listen",
3260 /* Takes a vector of packets. */
3261 .vector_size = sizeof (u32),
3262 .n_errors = TCP_N_ERROR,
3263 .error_strings = tcp_error_strings,
3264 .n_next_nodes = TCP_LISTEN_N_NEXT,
3267 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3268 foreach_tcp_state_next
3271 .format_trace = format_tcp_rx_trace_short,
3276 VLIB_REGISTER_NODE (tcp6_listen_node) =
3278 .name = "tcp6-listen",
3279 /* Takes a vector of packets. */
3280 .vector_size = sizeof (u32),
3281 .n_errors = TCP_N_ERROR,
3282 .error_strings = tcp_error_strings,
3283 .n_next_nodes = TCP_LISTEN_N_NEXT,
3286 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3287 foreach_tcp_state_next
3290 .format_trace = format_tcp_rx_trace_short,
3294 typedef enum _tcp_input_next
3296 TCP_INPUT_NEXT_DROP,
3297 TCP_INPUT_NEXT_LISTEN,
3298 TCP_INPUT_NEXT_RCV_PROCESS,
3299 TCP_INPUT_NEXT_SYN_SENT,
3300 TCP_INPUT_NEXT_ESTABLISHED,
3301 TCP_INPUT_NEXT_RESET,
3302 TCP_INPUT_NEXT_PUNT,
3306 #define foreach_tcp4_input_next \
3307 _ (DROP, "ip4-drop") \
3308 _ (LISTEN, "tcp4-listen") \
3309 _ (RCV_PROCESS, "tcp4-rcv-process") \
3310 _ (SYN_SENT, "tcp4-syn-sent") \
3311 _ (ESTABLISHED, "tcp4-established") \
3312 _ (RESET, "tcp4-reset") \
3313 _ (PUNT, "ip4-punt")
3315 #define foreach_tcp6_input_next \
3316 _ (DROP, "ip6-drop") \
3317 _ (LISTEN, "tcp6-listen") \
3318 _ (RCV_PROCESS, "tcp6-rcv-process") \
3319 _ (SYN_SENT, "tcp6-syn-sent") \
3320 _ (ESTABLISHED, "tcp6-established") \
3321 _ (RESET, "tcp6-reset") \
3322 _ (PUNT, "ip6-punt")
3324 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3327 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3328 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3330 tcp_connection_t *tc;
3335 for (i = 0; i < n_bufs; i++)
3337 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3339 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3340 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3342 tcp = vlib_buffer_get_current (bs[i]);
3343 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3349 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3351 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3353 *next = TCP_INPUT_NEXT_DROP;
3355 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3357 *next = TCP_INPUT_NEXT_PUNT;
3358 *error = TCP_ERROR_PUNT;
3362 *next = TCP_INPUT_NEXT_RESET;
3363 *error = TCP_ERROR_NO_LISTENER;
3367 always_inline tcp_connection_t *
3368 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3369 u8 is_ip4, u8 is_nolookup)
3371 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3372 int n_advance_bytes, n_data_bytes;
3373 transport_connection_t *tc;
3379 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3380 int ip_hdr_bytes = ip4_header_bytes (ip4);
3381 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3383 *error = TCP_ERROR_LENGTH;
3386 tcp = ip4_next_header (ip4);
3387 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3388 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3389 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3391 /* Length check. Checksum computed by ipx_local no need to compute again */
3392 if (PREDICT_FALSE (n_data_bytes < 0))
3394 *error = TCP_ERROR_LENGTH;
3399 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3400 &ip4->src_address, tcp->dst_port,
3402 TRANSPORT_PROTO_TCP, thread_index,
3407 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3408 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3410 *error = TCP_ERROR_LENGTH;
3413 tcp = ip6_next_header (ip6);
3414 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3415 n_advance_bytes = tcp_header_bytes (tcp);
3416 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3418 n_advance_bytes += sizeof (ip6[0]);
3420 if (PREDICT_FALSE (n_data_bytes < 0))
3422 *error = TCP_ERROR_LENGTH;
3429 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3431 ip4_main_t *im = &ip4_main;
3432 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3433 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3436 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3438 tcp->dst_port, tcp->src_port,
3439 TRANSPORT_PROTO_TCP,
3440 thread_index, &result);
3446 (transport_connection_t *) tcp_connection_get (vnet_buffer (b)->
3447 tcp.connection_index,
3450 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3451 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3452 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3453 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3454 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3456 vnet_buffer (b)->tcp.flags = 0;
3458 *error = result ? TCP_ERROR_NONE + result : *error;
3460 return tcp_get_connection_from_transport (tc);
3464 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3465 vlib_buffer_t * b, u16 * next, u32 * error)
3470 tcp = tcp_buffer_hdr (b);
3471 flags = tcp->flags & filter_flags;
3472 *next = tm->dispatch_table[tc->state][flags].next;
3473 *error = tm->dispatch_table[tc->state][flags].error;
3476 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3477 || *next == TCP_INPUT_NEXT_RESET))
3479 /* Overload tcp flags to store state */
3480 tcp_state_t state = tc->state;
3481 vnet_buffer (b)->tcp.flags = tc->state;
3483 if (*error == TCP_ERROR_DISPATCH)
3484 clib_warning ("tcp conn %u disp error state %U flags %U",
3485 tc->c_c_index, format_tcp_state, state,
3486 format_tcp_flags, (int) flags);
3491 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3492 vlib_frame_t * frame, int is_ip4, u8 is_nolookup)
3494 u32 n_left_from, *from, thread_index = vm->thread_index;
3495 tcp_main_t *tm = vnet_get_tcp_main ();
3496 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3497 u16 nexts[VLIB_FRAME_SIZE], *next;
3499 tcp_set_time_now (tcp_get_worker (thread_index));
3501 from = vlib_frame_vector_args (frame);
3502 n_left_from = frame->n_vectors;
3503 vlib_get_buffers (vm, from, bufs, n_left_from);
3508 while (n_left_from >= 4)
3510 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3511 tcp_connection_t *tc0, *tc1;
3514 vlib_prefetch_buffer_header (b[2], STORE);
3515 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3517 vlib_prefetch_buffer_header (b[3], STORE);
3518 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3521 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3523 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3525 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4,
3528 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3530 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3531 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3533 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3534 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3536 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3537 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3541 if (PREDICT_TRUE (tc0 != 0))
3543 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3544 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3545 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3548 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3550 if (PREDICT_TRUE (tc1 != 0))
3552 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3553 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3554 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3557 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3564 while (n_left_from > 0)
3566 tcp_connection_t *tc0;
3567 u32 error0 = TCP_ERROR_NO_LISTENER;
3569 if (n_left_from > 1)
3571 vlib_prefetch_buffer_header (b[1], STORE);
3572 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3575 next[0] = TCP_INPUT_NEXT_DROP;
3576 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3578 if (PREDICT_TRUE (tc0 != 0))
3580 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3581 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3582 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3585 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3592 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3593 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3595 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3596 return frame->n_vectors;
3599 VLIB_NODE_FN (tcp4_input_nolookup_node) (vlib_main_t * vm,
3600 vlib_node_runtime_t * node,
3601 vlib_frame_t * from_frame)
3603 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3604 1 /* is_nolookup */ );
3607 VLIB_NODE_FN (tcp6_input_nolookup_node) (vlib_main_t * vm,
3608 vlib_node_runtime_t * node,
3609 vlib_frame_t * from_frame)
3611 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3612 1 /* is_nolookup */ );
3616 VLIB_REGISTER_NODE (tcp4_input_nolookup_node) =
3618 .name = "tcp4-input-nolookup",
3619 /* Takes a vector of packets. */
3620 .vector_size = sizeof (u32),
3621 .n_errors = TCP_N_ERROR,
3622 .error_strings = tcp_error_strings,
3623 .n_next_nodes = TCP_INPUT_N_NEXT,
3626 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3627 foreach_tcp4_input_next
3630 .format_buffer = format_tcp_header,
3631 .format_trace = format_tcp_rx_trace,
3636 VLIB_REGISTER_NODE (tcp6_input_nolookup_node) =
3638 .name = "tcp6-input-nolookup",
3639 /* Takes a vector of packets. */
3640 .vector_size = sizeof (u32),
3641 .n_errors = TCP_N_ERROR,
3642 .error_strings = tcp_error_strings,
3643 .n_next_nodes = TCP_INPUT_N_NEXT,
3646 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3647 foreach_tcp6_input_next
3650 .format_buffer = format_tcp_header,
3651 .format_trace = format_tcp_rx_trace,
3655 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3656 vlib_frame_t * from_frame)
3658 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3659 0 /* is_nolookup */ );
3662 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3663 vlib_frame_t * from_frame)
3665 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3666 0 /* is_nolookup */ );
3670 VLIB_REGISTER_NODE (tcp4_input_node) =
3672 .name = "tcp4-input",
3673 /* Takes a vector of packets. */
3674 .vector_size = sizeof (u32),
3675 .n_errors = TCP_N_ERROR,
3676 .error_strings = tcp_error_strings,
3677 .n_next_nodes = TCP_INPUT_N_NEXT,
3680 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3681 foreach_tcp4_input_next
3684 .format_buffer = format_tcp_header,
3685 .format_trace = format_tcp_rx_trace,
3690 VLIB_REGISTER_NODE (tcp6_input_node) =
3692 .name = "tcp6-input",
3693 /* Takes a vector of packets. */
3694 .vector_size = sizeof (u32),
3695 .n_errors = TCP_N_ERROR,
3696 .error_strings = tcp_error_strings,
3697 .n_next_nodes = TCP_INPUT_N_NEXT,
3700 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3701 foreach_tcp6_input_next
3704 .format_buffer = format_tcp_header,
3705 .format_trace = format_tcp_rx_trace,
3709 #ifndef CLIB_MARCH_VARIANT
3711 tcp_dispatch_table_init (tcp_main_t * tm)
3714 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3715 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3717 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3718 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3721 #define _(t,f,n,e) \
3723 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3724 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3727 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3728 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3729 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3730 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3731 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3732 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3733 TCP_ERROR_ACK_INVALID);
3734 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3735 TCP_ERROR_SEGMENT_INVALID);
3736 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3737 TCP_ERROR_SEGMENT_INVALID);
3738 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3739 TCP_ERROR_INVALID_CONNECTION);
3740 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3741 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3742 TCP_ERROR_SEGMENT_INVALID);
3743 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3744 TCP_ERROR_SEGMENT_INVALID);
3745 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3747 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3748 TCP_ERROR_SEGMENT_INVALID);
3749 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3750 TCP_ERROR_SEGMENT_INVALID);
3751 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3752 TCP_ERROR_SEGMENT_INVALID);
3753 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3754 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3755 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3756 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3757 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3758 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3760 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3761 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3763 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3765 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3766 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3767 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3768 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3770 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3772 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3773 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3774 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3776 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3777 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3778 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3779 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3780 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3781 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3782 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3783 /* SYN-ACK for a SYN */
3784 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3786 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3787 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3788 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3790 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3791 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3793 /* ACK for for established connection -> tcp-established. */
3794 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3795 /* FIN for for established connection -> tcp-established. */
3796 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3797 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3799 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3801 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3802 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3803 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3805 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3806 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3807 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3808 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3809 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3810 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3811 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3812 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3814 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3815 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3817 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3819 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3820 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3821 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3822 /* ACK or FIN-ACK to our FIN */
3823 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3824 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3826 /* FIN in reply to our FIN from the other side */
3827 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3828 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3829 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3831 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3832 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3833 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3834 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3835 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3836 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3837 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3839 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3840 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3841 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3842 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3844 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3846 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3847 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3848 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3849 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3851 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3852 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3853 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3854 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3856 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3858 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3859 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3860 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3861 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3863 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3864 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3866 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3868 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3869 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3870 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3872 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3873 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3874 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3875 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3876 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3877 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3878 /* FIN confirming that the peer (app) has closed */
3879 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3880 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3881 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3883 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3884 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3886 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3887 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3889 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3890 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3892 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3893 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3894 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3895 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3897 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3899 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3900 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3901 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3903 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3904 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3905 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3906 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3907 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3908 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3909 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3910 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3912 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3913 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3915 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3917 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3918 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3919 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3920 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3921 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3923 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3924 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3926 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3927 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3928 * incoming segment not containing a RST causes a RST to be sent in
3930 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3931 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3932 TCP_ERROR_CONNECTION_CLOSED);
3933 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3934 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3935 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3940 static clib_error_t *
3941 tcp_input_init (vlib_main_t * vm)
3943 clib_error_t *error = 0;
3944 tcp_main_t *tm = vnet_get_tcp_main ();
3946 if ((error = vlib_call_init_function (vm, tcp_init)))
3949 /* Initialize dispatch table. */
3950 tcp_dispatch_table_init (tm);
3955 VLIB_INIT_FUNCTION (tcp_input_init);
3957 #endif /* CLIB_MARCH_VARIANT */
3960 * fd.io coding-style-patch-verification: ON
3963 * eval: (c-set-style "gnu")