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 sack_scoreboard_hole_t *hole;
1303 ASSERT (tcp_in_cong_recovery (tc));
1305 hole = scoreboard_first_hole (&tc->sack_sb);
1306 if (hole && hole->start == tc->snd_una && hole->end == tc->snd_nxt)
1307 scoreboard_clear (&tc->sack_sb);
1309 if (tcp_cc_is_spurious_retransmit (tc))
1311 tcp_cc_congestion_undo (tc);
1315 if (tcp_in_recovery (tc))
1316 tcp_cc_recovery_exit (tc);
1317 else if (tcp_in_fastrecovery (tc))
1319 tcp_cc_recovered (tc);
1320 tcp_cc_fastrecovery_clear (tc);
1323 ASSERT (tc->rto_boff == 0);
1324 ASSERT (!tcp_in_cong_recovery (tc));
1325 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1330 tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1332 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1334 /* Congestion avoidance */
1335 tcp_cc_rcv_ack (tc, rs);
1337 /* If a cumulative ack, make sure dupacks is 0 */
1338 tc->rcv_dupacks = 0;
1340 /* When dupacks hits the threshold we only enter fast retransmit if
1341 * cumulative ack covers more than snd_congestion. Should snd_una
1342 * wrap this test may fail under otherwise valid circumstances.
1343 * Therefore, proactively update snd_congestion when wrap detected. */
1345 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1346 && seq_gt (tc->snd_congestion, tc->snd_una)))
1347 tc->snd_congestion = tc->snd_una - 1;
1351 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1353 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1357 tcp_should_fastrecover (tcp_connection_t * tc)
1359 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1360 || tcp_should_fastrecover_sack (tc));
1364 * One function to rule them all ... and in the darkness bind them
1367 tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs,
1372 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1374 if (tc->bytes_acked)
1376 tcp_program_fastretransmit (tc);
1380 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1381 * it account for the bytes that left the network.
1383 else if (is_dack && !tcp_in_recovery (tc))
1385 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1386 ASSERT (tc->snd_una != tc->snd_nxt || tc->sack_sb.last_sacked_bytes);
1390 /* Pure duplicate ack. If some data got acked, it's handled lower */
1391 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1393 ASSERT (tcp_in_fastrecovery (tc));
1394 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1397 else if (tcp_should_fastrecover (tc))
1401 ASSERT (!tcp_in_fastrecovery (tc));
1403 /* Heuristic to catch potential late dupacks
1404 * after fast retransmit exits */
1405 if (is_dack && tc->snd_una == tc->snd_congestion
1406 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1408 tc->rcv_dupacks = 0;
1412 tcp_cc_init_congestion (tc);
1414 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1415 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1417 /* Constrain rate until we get a partial ack */
1418 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1419 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1420 0 /* start bucket */ );
1421 tcp_program_fastretransmit (tc);
1424 else if (!tc->bytes_acked
1425 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1427 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1433 /* Don't allow entry in fast recovery if still in recovery, for now */
1434 else if (0 && is_dack && tcp_in_recovery (tc))
1436 /* If of of the two conditions lower hold, reset dupacks because
1437 * we're probably after timeout (RFC6582 heuristics).
1438 * If Cumulative ack does not cover more than congestion threshold,
1440 * 1) The following doesn't hold: The congestion window is greater
1441 * than SMSS bytes and the difference between highest_ack
1442 * and prev_highest_ack is at most 4*SMSS bytes
1443 * 2) Echoed timestamp in the last non-dup ack does not equal the
1446 if (seq_leq (tc->snd_una, tc->snd_congestion)
1447 && ((!(tc->cwnd > tc->snd_mss
1448 && tc->bytes_acked <= 4 * tc->snd_mss))
1449 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1451 tc->rcv_dupacks = 0;
1456 if (!tc->bytes_acked)
1460 TCP_EVT (TCP_EVT_CC_PACK, tc);
1463 * Legitimate ACK. 1) See if we can exit recovery
1466 /* Update the pacing rate. For the first partial ack we move from
1467 * the artificially constrained rate to the one after congestion */
1468 tcp_connection_tx_pacer_update (tc);
1470 if (seq_geq (tc->snd_una, tc->snd_congestion))
1472 tcp_retransmit_timer_update (tc);
1474 /* If spurious return, we've already updated everything */
1475 if (tcp_cc_recover (tc))
1477 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1481 /* Treat as congestion avoidance ack */
1482 tcp_cc_rcv_ack (tc, rs);
1487 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1490 /* XXX limit this only to first partial ack? */
1491 tcp_retransmit_timer_update (tc);
1493 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1494 * reset dupacks to 0. Also needed if in congestion recovery */
1495 tc->rcv_dupacks = 0;
1497 /* Post RTO timeout don't try anything fancy */
1498 if (tcp_in_recovery (tc))
1500 tcp_cc_rcv_ack (tc, rs);
1501 transport_add_tx_event (&tc->connection);
1505 /* Remove retransmitted bytes that have been delivered */
1506 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1508 ASSERT (tc->bytes_acked >= tc->sack_sb.last_bytes_delivered
1509 || (tc->flags & TCP_CONN_FINSNT));
1511 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1512 * remove sacked bytes delivered */
1513 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1515 rxt_delivered = tc->bytes_acked - tc->sack_sb.last_bytes_delivered;
1516 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1517 tc->snd_rxt_bytes -= rxt_delivered;
1521 /* Apparently all retransmitted holes have been acked */
1522 tc->snd_rxt_bytes = 0;
1523 tc->sack_sb.high_rxt = tc->snd_una;
1528 tcp_fastrecovery_first_on (tc);
1529 if (tc->snd_rxt_bytes > tc->bytes_acked)
1530 tc->snd_rxt_bytes -= tc->bytes_acked;
1532 tc->snd_rxt_bytes = 0;
1535 tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs);
1538 * Since this was a partial ack, try to retransmit some more data
1540 tcp_program_fastretransmit (tc);
1544 * Process incoming ACK
1547 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1548 tcp_header_t * th, u32 * error)
1550 u32 prev_snd_wnd, prev_snd_una;
1551 tcp_rate_sample_t rs = { 0 };
1554 TCP_EVT (TCP_EVT_CC_STAT, tc);
1556 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1557 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1559 /* We've probably entered recovery and the peer still has some
1560 * of the data we've sent. Update snd_nxt and accept the ack */
1561 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1562 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1564 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1568 tc->errors.above_ack_wnd += 1;
1569 *error = TCP_ERROR_ACK_FUTURE;
1570 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 0, vnet_buffer (b)->tcp.ack_number);
1574 /* If old ACK, probably it's an old dupack */
1575 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1577 tc->errors.below_ack_wnd += 1;
1578 *error = TCP_ERROR_ACK_OLD;
1579 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 1, vnet_buffer (b)->tcp.ack_number);
1580 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1581 tcp_cc_handle_event (tc, 0, 1);
1582 /* Don't drop yet */
1589 * Looks okay, process feedback
1592 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1593 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1595 prev_snd_wnd = tc->snd_wnd;
1596 prev_snd_una = tc->snd_una;
1597 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1598 vnet_buffer (b)->tcp.ack_number,
1599 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1600 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1601 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
1602 tcp_validate_txf_size (tc, tc->bytes_acked);
1604 if (tc->bytes_acked)
1606 tcp_program_dequeue (wrk, tc);
1607 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1610 if (tc->flags & TCP_CONN_RATE_SAMPLE)
1611 tcp_bt_sample_delivery_rate (tc, &rs);
1613 TCP_EVT (TCP_EVT_ACK_RCVD, tc);
1616 * Check if we have congestion event
1619 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1621 tcp_cc_handle_event (tc, &rs, is_dack);
1622 tc->dupacks_in += is_dack;
1623 if (!tcp_in_cong_recovery (tc))
1625 *error = TCP_ERROR_ACK_OK;
1628 *error = TCP_ERROR_ACK_DUP;
1629 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1635 * Update congestion control (slow start/congestion avoidance)
1637 tcp_cc_update (tc, &rs);
1638 *error = TCP_ERROR_ACK_OK;
1643 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1645 if (!tcp_disconnect_pending (tc))
1647 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1648 tcp_disconnect_pending_on (tc);
1653 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1655 u32 thread_index, *pending_disconnects;
1656 tcp_connection_t *tc;
1659 if (!vec_len (wrk->pending_disconnects))
1662 thread_index = wrk->vm->thread_index;
1663 pending_disconnects = wrk->pending_disconnects;
1664 for (i = 0; i < vec_len (pending_disconnects); i++)
1666 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1667 tcp_disconnect_pending_off (tc);
1668 session_transport_closing_notify (&tc->connection);
1670 _vec_len (wrk->pending_disconnects) = 0;
1674 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1677 /* Reject out-of-order fins */
1678 if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt)
1681 /* Account for the FIN and send ack */
1683 tcp_program_ack (tc);
1684 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1685 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1686 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1687 tcp_program_disconnect (wrk, tc);
1688 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
1689 TCP_EVT (TCP_EVT_FIN_RCVD, tc);
1690 *error = TCP_ERROR_FIN_RCVD;
1693 #ifndef CLIB_MARCH_VARIANT
1695 tcp_sack_vector_is_sane (sack_block_t * sacks)
1698 for (i = 1; i < vec_len (sacks); i++)
1700 if (sacks[i - 1].end == sacks[i].start)
1707 * Build SACK list as per RFC2018.
1709 * Makes sure the first block contains the segment that generated the current
1710 * ACK and the following ones are the ones most recently reported in SACK
1713 * @param tc TCP connection for which the SACK list is updated
1714 * @param start Start sequence number of the newest SACK block
1715 * @param end End sequence of the newest SACK block
1718 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1720 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1723 /* If the first segment is ooo add it to the list. Last write might've moved
1724 * rcv_nxt over the first segment. */
1725 if (seq_lt (tc->rcv_nxt, start))
1727 vec_add2 (new_list, block, 1);
1728 block->start = start;
1732 /* Find the blocks still worth keeping. */
1733 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1735 /* Discard if rcv_nxt advanced beyond current block */
1736 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1739 /* Merge or drop if segment overlapped by the new segment */
1740 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1741 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1743 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1744 new_list[0].start = tc->snd_sacks[i].start;
1745 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1746 new_list[0].end = tc->snd_sacks[i].end;
1750 /* Save to new SACK list if we have space. */
1751 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1752 vec_add1 (new_list, tc->snd_sacks[i]);
1755 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1757 /* Replace old vector with new one */
1758 vec_reset_length (tc->snd_sacks);
1759 tc->snd_sacks_fl = tc->snd_sacks;
1760 tc->snd_sacks = new_list;
1762 /* Segments should not 'touch' */
1763 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1767 tcp_sack_list_bytes (tcp_connection_t * tc)
1770 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1771 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1774 #endif /* CLIB_MARCH_VARIANT */
1776 /** Enqueue data for delivery to application */
1778 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1781 int written, error = TCP_ERROR_ENQUEUED;
1783 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1785 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1786 1 /* queue event */ , 1);
1787 tc->bytes_in += written;
1789 TCP_EVT (TCP_EVT_INPUT, tc, 0, data_len, written);
1791 /* Update rcv_nxt */
1792 if (PREDICT_TRUE (written == data_len))
1794 tc->rcv_nxt += written;
1796 /* If more data written than expected, account for out-of-order bytes. */
1797 else if (written > data_len)
1799 tc->rcv_nxt += written;
1800 TCP_EVT (TCP_EVT_CC_INPUT, tc, data_len, written);
1802 else if (written > 0)
1804 /* We've written something but FIFO is probably full now */
1805 tc->rcv_nxt += written;
1806 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1810 return TCP_ERROR_FIFO_FULL;
1813 /* Update SACK list if need be */
1814 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1816 /* Remove SACK blocks that have been delivered */
1817 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1823 /** Enqueue out-of-order data */
1825 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1831 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1834 /* Enqueue out-of-order data with relative offset */
1835 rv = session_enqueue_stream_connection (&tc->connection, b,
1836 vnet_buffer (b)->tcp.seq_number -
1837 tc->rcv_nxt, 0 /* queue event */ ,
1840 /* Nothing written */
1843 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, 0);
1844 return TCP_ERROR_FIFO_FULL;
1847 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1848 tc->bytes_in += data_len;
1850 /* Update SACK list if in use */
1851 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1853 ooo_segment_t *newest;
1856 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1858 /* Get the newest segment from the fifo */
1859 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1862 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1863 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1864 start = tc->rcv_nxt + offset;
1865 end = start + ooo_segment_length (s0->rx_fifo, newest);
1866 tcp_update_sack_list (tc, start, end);
1867 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1868 TCP_EVT (TCP_EVT_CC_SACKS, tc);
1872 return TCP_ERROR_ENQUEUED_OOO;
1876 * Check if ACK could be delayed. If ack can be delayed, it should return
1877 * true for a full frame. If we're always acking return 0.
1880 tcp_can_delack (tcp_connection_t * tc)
1882 /* Send ack if ... */
1884 /* just sent a rcv wnd 0
1885 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1886 /* constrained to send ack */
1887 || (tc->flags & TCP_CONN_SNDACK) != 0
1888 /* we're almost out of tx wnd */
1889 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1896 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1898 u32 discard, first = b->current_length;
1899 vlib_main_t *vm = vlib_get_main ();
1901 /* Handle multi-buffer segments */
1902 if (n_bytes_to_drop > b->current_length)
1904 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1908 discard = clib_min (n_bytes_to_drop, b->current_length);
1909 vlib_buffer_advance (b, discard);
1910 b = vlib_get_buffer (vm, b->next_buffer);
1911 n_bytes_to_drop -= discard;
1913 while (n_bytes_to_drop);
1914 if (n_bytes_to_drop > first)
1915 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1918 vlib_buffer_advance (b, n_bytes_to_drop);
1919 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1924 * Receive buffer for connection and handle acks
1926 * It handles both in order or out-of-order data.
1929 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1932 u32 error, n_bytes_to_drop, n_data_bytes;
1934 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1935 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1936 ASSERT (n_data_bytes);
1937 tc->data_segs_in += 1;
1939 /* Handle out-of-order data */
1940 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1942 /* Old sequence numbers allowed through because they overlapped
1944 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1946 /* Completely in the past (possible retransmit). Ack
1947 * retransmissions since we may not have any data to send */
1948 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1950 tcp_program_ack (tc);
1951 error = TCP_ERROR_SEGMENT_OLD;
1955 /* Chop off the bytes in the past and see if what is left
1956 * can be enqueued in order */
1957 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1958 n_data_bytes -= n_bytes_to_drop;
1959 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1960 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1962 error = TCP_ERROR_SEGMENT_OLD;
1968 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1969 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1970 tcp_program_dupack (tc);
1971 TCP_EVT (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1972 tc->errors.above_data_wnd += seq_gt (vnet_buffer (b)->tcp.seq_end,
1973 tc->rcv_las + tc->rcv_wnd);
1979 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1980 * segments can be enqueued after fifo tail offset changes. */
1981 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1982 if (tcp_can_delack (tc))
1984 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1985 tcp_timer_set (tc, TCP_TIMER_DELACK, tcp_cfg.delack_time);
1989 tcp_program_ack (tc);
1997 tcp_header_t tcp_header;
1998 tcp_connection_t tcp_connection;
2002 format_tcp_rx_trace (u8 * s, va_list * args)
2004 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2005 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2006 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2007 u32 indent = format_get_indent (s);
2009 s = format (s, "%U\n%U%U",
2010 format_tcp_header, &t->tcp_header, 128,
2011 format_white_space, indent,
2012 format_tcp_connection, &t->tcp_connection, 1);
2018 format_tcp_rx_trace_short (u8 * s, va_list * args)
2020 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2021 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2022 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2024 s = format (s, "%d -> %d (%U)",
2025 clib_net_to_host_u16 (t->tcp_header.dst_port),
2026 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2027 t->tcp_connection.state);
2033 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2034 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2038 clib_memcpy_fast (&t0->tcp_connection, tc0,
2039 sizeof (t0->tcp_connection));
2043 th0 = tcp_buffer_hdr (b0);
2045 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2049 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2050 vlib_frame_t * frame, u8 is_ip4)
2054 n_left = frame->n_vectors;
2055 from = vlib_frame_vector_args (frame);
2059 tcp_connection_t *tc0;
2066 b0 = vlib_get_buffer (vm, bi0);
2068 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2070 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2071 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2073 th0 = tcp_buffer_hdr (b0);
2074 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2083 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2084 u8 is_ip4, u32 evt, u32 val)
2087 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2089 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2092 #define tcp_maybe_inc_counter(node_id, err, count) \
2094 if (next0 != tcp_next_drop (is_ip4)) \
2095 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2096 tcp6_##node_id##_node.index, is_ip4, err, \
2099 #define tcp_inc_counter(node_id, err, count) \
2100 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2101 tcp6_##node_id##_node.index, is_ip4, \
2103 #define tcp_maybe_inc_err_counter(cnts, err) \
2105 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2107 #define tcp_inc_err_counter(cnts, err, val) \
2111 #define tcp_store_err_counters(node_id, cnts) \
2114 for (i = 0; i < TCP_N_ERROR; i++) \
2116 tcp_inc_counter(node_id, i, cnts[i]); \
2121 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2122 vlib_frame_t * frame, int is_ip4)
2124 u32 thread_index = vm->thread_index, errors = 0;
2125 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2126 u32 n_left_from, *from, *first_buffer;
2127 u16 err_counters[TCP_N_ERROR] = { 0 };
2129 if (node->flags & VLIB_NODE_FLAG_TRACE)
2130 tcp_established_trace_frame (vm, node, frame, is_ip4);
2132 first_buffer = from = vlib_frame_vector_args (frame);
2133 n_left_from = frame->n_vectors;
2135 while (n_left_from > 0)
2137 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2140 tcp_connection_t *tc0;
2142 if (n_left_from > 1)
2145 pb = vlib_get_buffer (vm, from[1]);
2146 vlib_prefetch_buffer_header (pb, LOAD);
2147 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2154 b0 = vlib_get_buffer (vm, bi0);
2155 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2158 if (PREDICT_FALSE (tc0 == 0))
2160 error0 = TCP_ERROR_INVALID_CONNECTION;
2164 th0 = tcp_buffer_hdr (b0);
2166 /* TODO header prediction fast path */
2168 /* 1-4: check SEQ, RST, SYN */
2169 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2171 TCP_EVT (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2175 /* 5: check the ACK field */
2176 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2179 /* 6: check the URG bit TODO */
2181 /* 7: process the segment text */
2182 if (vnet_buffer (b0)->tcp.data_len)
2183 error0 = tcp_segment_rcv (wrk, tc0, b0);
2185 /* 8: check the FIN bit */
2186 if (PREDICT_FALSE (tcp_is_fin (th0)))
2187 tcp_rcv_fin (wrk, tc0, b0, &error0);
2190 tcp_inc_err_counter (err_counters, error0, 1);
2193 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2195 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2196 tcp_store_err_counters (established, err_counters);
2197 tcp_handle_postponed_dequeues (wrk);
2198 tcp_handle_disconnects (wrk);
2199 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2201 return frame->n_vectors;
2204 VLIB_NODE_FN (tcp4_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, 1 /* is_ip4 */ );
2211 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2212 vlib_node_runtime_t * node,
2213 vlib_frame_t * from_frame)
2215 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2219 VLIB_REGISTER_NODE (tcp4_established_node) =
2221 .name = "tcp4-established",
2222 /* Takes a vector of packets. */
2223 .vector_size = sizeof (u32),
2224 .n_errors = TCP_N_ERROR,
2225 .error_strings = tcp_error_strings,
2226 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2229 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2230 foreach_tcp_state_next
2233 .format_trace = format_tcp_rx_trace_short,
2238 VLIB_REGISTER_NODE (tcp6_established_node) =
2240 .name = "tcp6-established",
2241 /* Takes a vector of packets. */
2242 .vector_size = sizeof (u32),
2243 .n_errors = TCP_N_ERROR,
2244 .error_strings = tcp_error_strings,
2245 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2248 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2249 foreach_tcp_state_next
2252 .format_trace = format_tcp_rx_trace_short,
2258 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2260 transport_connection_t *tmp = 0;
2267 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2270 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2271 && (tc->state == TCP_STATE_LISTEN
2272 || tc->c_rmt_port == hdr->src_port));
2276 handle = session_lookup_half_open_handle (&tc->connection);
2277 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2278 tc->c_proto, tc->c_is_ip4);
2282 if (tmp->lcl_port == hdr->dst_port
2283 && tmp->rmt_port == hdr->src_port)
2285 TCP_DBG ("half-open is valid!");
2293 * Lookup transport connection
2295 static tcp_connection_t *
2296 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2300 transport_connection_t *tconn;
2301 tcp_connection_t *tc;
2306 ip4 = vlib_buffer_get_current (b);
2307 tcp = ip4_next_header (ip4);
2308 tconn = session_lookup_connection_wt4 (fib_index,
2313 TRANSPORT_PROTO_TCP,
2314 thread_index, &is_filtered);
2315 tc = tcp_get_connection_from_transport (tconn);
2316 ASSERT (tcp_lookup_is_valid (tc, tcp));
2321 ip6 = vlib_buffer_get_current (b);
2322 tcp = ip6_next_header (ip6);
2323 tconn = session_lookup_connection_wt6 (fib_index,
2328 TRANSPORT_PROTO_TCP,
2329 thread_index, &is_filtered);
2330 tc = tcp_get_connection_from_transport (tconn);
2331 ASSERT (tcp_lookup_is_valid (tc, tcp));
2337 tcp_check_tx_offload (tcp_connection_t * tc, int is_ipv4)
2339 vnet_main_t *vnm = vnet_get_main ();
2340 const dpo_id_t *dpo;
2341 const load_balance_t *lb;
2342 vnet_hw_interface_t *hw_if;
2343 u32 sw_if_idx, lb_idx;
2347 ip4_address_t *dst_addr = &(tc->c_rmt_ip.ip4);
2348 lb_idx = ip4_fib_forwarding_lookup (tc->c_fib_index, dst_addr);
2352 ip6_address_t *dst_addr = &(tc->c_rmt_ip.ip6);
2353 lb_idx = ip6_fib_table_fwding_lookup (tc->c_fib_index, dst_addr);
2356 lb = load_balance_get (lb_idx);
2357 dpo = load_balance_get_bucket_i (lb, 0);
2359 sw_if_idx = dpo->dpoi_index;
2360 hw_if = vnet_get_sup_hw_interface (vnm, sw_if_idx);
2363 ((hw_if->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO) == 0) ? 0 : 1;
2368 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2369 vlib_frame_t * from_frame, int is_ip4)
2371 u32 n_left_from, *from, *first_buffer, errors = 0;
2372 u32 my_thread_index = vm->thread_index;
2373 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2375 from = first_buffer = vlib_frame_vector_args (from_frame);
2376 n_left_from = from_frame->n_vectors;
2378 while (n_left_from > 0)
2380 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2381 tcp_connection_t *tc0, *new_tc0;
2382 tcp_header_t *tcp0 = 0;
2390 b0 = vlib_get_buffer (vm, bi0);
2392 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2393 if (PREDICT_FALSE (tc0 == 0))
2395 error0 = TCP_ERROR_INVALID_CONNECTION;
2399 /* Half-open completed recently but the connection was't removed
2400 * yet by the owning thread */
2401 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2403 /* Make sure the connection actually exists */
2404 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2405 my_thread_index, is_ip4));
2406 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2410 ack0 = vnet_buffer (b0)->tcp.ack_number;
2411 seq0 = vnet_buffer (b0)->tcp.seq_number;
2412 tcp0 = tcp_buffer_hdr (b0);
2414 /* Crude check to see if the connection handle does not match
2415 * the packet. Probably connection just switched to established */
2416 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2417 || tcp0->src_port != tc0->c_rmt_port))
2419 error0 = TCP_ERROR_INVALID_CONNECTION;
2423 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2424 && !tcp_syn (tcp0)))
2426 error0 = TCP_ERROR_SEGMENT_INVALID;
2430 /* SYNs consume sequence numbers */
2431 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2434 * 1. check the ACK bit
2438 * If the ACK bit is set
2439 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2440 * the RST bit is set, if so drop the segment and return)
2441 * <SEQ=SEG.ACK><CTL=RST>
2442 * and discard the segment. Return.
2443 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2447 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2449 if (!tcp_rst (tcp0))
2450 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2451 error0 = TCP_ERROR_RCV_WND;
2455 /* Make sure ACK is valid */
2456 if (seq_gt (tc0->snd_una, ack0))
2458 error0 = TCP_ERROR_ACK_INVALID;
2464 * 2. check the RST bit
2469 /* If ACK is acceptable, signal client that peer is not
2470 * willing to accept connection and drop connection*/
2472 tcp_connection_reset (tc0);
2473 error0 = TCP_ERROR_RST_RCVD;
2478 * 3. check the security and precedence (skipped)
2482 * 4. check the SYN bit
2485 /* No SYN flag. Drop. */
2486 if (!tcp_syn (tcp0))
2488 error0 = TCP_ERROR_SEGMENT_INVALID;
2493 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2495 error0 = TCP_ERROR_OPTIONS;
2499 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2500 * current thread pool. */
2501 new_tc0 = tcp_connection_alloc_w_base (my_thread_index, tc0);
2502 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2503 new_tc0->irs = seq0;
2504 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2505 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2507 /* If this is not the owning thread, wait for syn retransmit to
2508 * expire and cleanup then */
2509 if (tcp_half_open_connection_cleanup (tc0))
2510 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2512 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2514 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2515 new_tc0->tsval_recent_age = tcp_time_now ();
2518 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2519 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2521 new_tc0->rcv_wscale = 0;
2523 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2524 << new_tc0->snd_wscale;
2525 new_tc0->snd_wl1 = seq0;
2526 new_tc0->snd_wl2 = ack0;
2528 tcp_connection_init_vars (new_tc0);
2530 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2531 if (PREDICT_TRUE (tcp_ack (tcp0)))
2533 /* Our SYN is ACKed: we have iss < ack = snd_una */
2535 /* TODO Dequeue acknowledged segments if we support Fast Open */
2536 new_tc0->snd_una = ack0;
2537 new_tc0->state = TCP_STATE_ESTABLISHED;
2539 /* Make sure las is initialized for the wnd computation */
2540 new_tc0->rcv_las = new_tc0->rcv_nxt;
2542 /* Notify app that we have connection. If session layer can't
2543 * allocate session send reset */
2544 if (session_stream_connect_notify (&new_tc0->connection, 0))
2546 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2547 tcp_connection_cleanup (new_tc0);
2548 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2552 new_tc0->tx_fifo_size =
2553 transport_tx_fifo_size (&new_tc0->connection);
2554 /* Update rtt with the syn-ack sample */
2555 tcp_estimate_initial_rtt (new_tc0);
2556 TCP_EVT (TCP_EVT_SYNACK_RCVD, new_tc0);
2557 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2559 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2562 new_tc0->state = TCP_STATE_SYN_RCVD;
2564 /* Notify app that we have connection */
2565 if (session_stream_connect_notify (&new_tc0->connection, 0))
2567 tcp_connection_cleanup (new_tc0);
2568 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2569 TCP_EVT (TCP_EVT_RST_SENT, tc0);
2570 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2574 new_tc0->tx_fifo_size =
2575 transport_tx_fifo_size (&new_tc0->connection);
2576 new_tc0->rtt_ts = 0;
2577 tcp_init_snd_vars (new_tc0);
2578 tcp_send_synack (new_tc0);
2579 error0 = TCP_ERROR_SYNS_RCVD;
2583 tcp_check_tx_offload (new_tc0, is_ip4);
2585 /* Read data, if any */
2586 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2588 clib_warning ("rcvd data in syn-sent");
2589 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2590 if (error0 == TCP_ERROR_ACK_OK)
2591 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2595 tcp_program_ack (new_tc0);
2600 tcp_inc_counter (syn_sent, error0, 1);
2601 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2603 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2604 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2605 clib_memcpy_fast (&t0->tcp_connection, tc0,
2606 sizeof (t0->tcp_connection));
2610 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2612 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2613 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2615 return from_frame->n_vectors;
2618 VLIB_NODE_FN (tcp4_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, 1 /* is_ip4 */ );
2625 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2626 vlib_node_runtime_t * node,
2627 vlib_frame_t * from_frame)
2629 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2633 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2635 .name = "tcp4-syn-sent",
2636 /* Takes a vector of packets. */
2637 .vector_size = sizeof (u32),
2638 .n_errors = TCP_N_ERROR,
2639 .error_strings = tcp_error_strings,
2640 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2643 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2644 foreach_tcp_state_next
2647 .format_trace = format_tcp_rx_trace_short,
2652 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2654 .name = "tcp6-syn-sent",
2655 /* Takes a vector of packets. */
2656 .vector_size = sizeof (u32),
2657 .n_errors = TCP_N_ERROR,
2658 .error_strings = tcp_error_strings,
2659 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2662 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2663 foreach_tcp_state_next
2666 .format_trace = format_tcp_rx_trace_short,
2671 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2672 * as per RFC793 p. 64
2675 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2676 vlib_frame_t * from_frame, int is_ip4)
2678 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2679 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2680 u32 n_left_from, *from, max_dequeue;
2682 from = first_buffer = vlib_frame_vector_args (from_frame);
2683 n_left_from = from_frame->n_vectors;
2685 while (n_left_from > 0)
2687 u32 bi0, error0 = TCP_ERROR_NONE;
2688 tcp_header_t *tcp0 = 0;
2689 tcp_connection_t *tc0;
2697 b0 = vlib_get_buffer (vm, bi0);
2698 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2700 if (PREDICT_FALSE (tc0 == 0))
2702 error0 = TCP_ERROR_INVALID_CONNECTION;
2706 tcp0 = tcp_buffer_hdr (b0);
2707 is_fin0 = tcp_is_fin (tcp0);
2711 tcp_connection_t *tmp;
2712 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2714 if (tmp->state != tc0->state)
2716 if (tc0->state != TCP_STATE_CLOSED)
2717 clib_warning ("state changed");
2723 * Special treatment for CLOSED
2725 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2727 error0 = TCP_ERROR_CONNECTION_CLOSED;
2732 * For all other states (except LISTEN)
2735 /* 1-4: check SEQ, RST, SYN */
2736 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2739 /* 5: check the ACK field */
2742 case TCP_STATE_SYN_RCVD:
2744 /* Make sure the segment is exactly right */
2745 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2747 tcp_connection_reset (tc0);
2748 error0 = TCP_ERROR_SEGMENT_INVALID;
2753 * If the segment acknowledgment is not acceptable, form a
2755 * <SEQ=SEG.ACK><CTL=RST>
2758 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2760 tcp_connection_reset (tc0);
2764 /* Update rtt and rto */
2765 tcp_estimate_initial_rtt (tc0);
2767 /* Switch state to ESTABLISHED */
2768 tc0->state = TCP_STATE_ESTABLISHED;
2769 TCP_EVT (TCP_EVT_STATE_CHANGE, tc0);
2771 tcp_check_tx_offload (tc0, is_ip4);
2773 /* Initialize session variables */
2774 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2775 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2776 << tc0->rcv_opts.wscale;
2777 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2778 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2780 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2781 tcp_retransmit_timer_reset (tc0);
2782 if (session_stream_accept_notify (&tc0->connection))
2784 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2785 tcp_connection_reset (tc0);
2788 error0 = TCP_ERROR_ACK_OK;
2790 case TCP_STATE_ESTABLISHED:
2791 /* We can get packets in established state here because they
2792 * were enqueued before state change */
2793 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2797 case TCP_STATE_FIN_WAIT_1:
2798 /* In addition to the processing for the ESTABLISHED state, if
2799 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2800 * continue processing in that state. */
2801 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2804 /* Still have to send the FIN */
2805 if (tc0->flags & TCP_CONN_FINPNDG)
2807 /* TX fifo finally drained */
2808 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2809 if (max_dequeue <= tc0->burst_acked)
2811 /* If a fin was received and data was acked extend wait */
2812 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
2813 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2814 tcp_cfg.closewait_time);
2816 /* If FIN is ACKed */
2817 else if (tc0->snd_una == tc0->snd_nxt)
2819 /* Stop all retransmit timers because we have nothing more
2821 tcp_connection_timers_reset (tc0);
2823 /* We already have a FIN but didn't transition to CLOSING
2824 * because of outstanding tx data. Close the connection. */
2825 if (tc0->flags & TCP_CONN_FINRCVD)
2827 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2828 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE,
2829 tcp_cfg.cleanup_time);
2830 session_transport_closed_notify (&tc0->connection);
2834 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2835 /* Enable waitclose because we're willing to wait for peer's
2836 * FIN but not indefinitely. */
2837 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait2_time);
2839 /* Don't try to deq the FIN acked */
2840 if (tc0->burst_acked > 1)
2841 session_tx_fifo_dequeue_drop (&tc0->connection,
2842 tc0->burst_acked - 1);
2843 tc0->burst_acked = 0;
2846 case TCP_STATE_FIN_WAIT_2:
2847 /* In addition to the processing for the ESTABLISHED state, if
2848 * the retransmission queue is empty, the user's CLOSE can be
2849 * acknowledged ("ok") but do not delete the TCB. */
2850 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2852 tc0->burst_acked = 0;
2854 case TCP_STATE_CLOSE_WAIT:
2855 /* Do the same processing as for the ESTABLISHED state. */
2856 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2859 if (!(tc0->flags & TCP_CONN_FINPNDG))
2862 /* Still have outstanding tx data */
2863 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2864 if (max_dequeue > tc0->burst_acked)
2868 tcp_connection_timers_reset (tc0);
2869 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2870 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2872 case TCP_STATE_CLOSING:
2873 /* In addition to the processing for the ESTABLISHED state, if
2874 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2875 * otherwise ignore the segment. */
2876 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2879 if (tc0->snd_una != tc0->snd_nxt)
2882 tcp_connection_timers_reset (tc0);
2883 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2884 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2885 session_transport_closed_notify (&tc0->connection);
2889 case TCP_STATE_LAST_ACK:
2890 /* The only thing that [should] arrive in this state is an
2891 * acknowledgment of our FIN. If our FIN is now acknowledged,
2892 * delete the TCB, enter the CLOSED state, and return. */
2894 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2897 /* Apparently our ACK for the peer's FIN was lost */
2898 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2904 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2905 session_transport_closed_notify (&tc0->connection);
2907 /* Don't free the connection from the data path since
2908 * we can't ensure that we have no packets already enqueued
2909 * to output. Rely instead on the waitclose timer */
2910 tcp_connection_timers_reset (tc0);
2911 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
2916 case TCP_STATE_TIME_WAIT:
2917 /* The only thing that can arrive in this state is a
2918 * retransmission of the remote FIN. Acknowledge it, and restart
2919 * the 2 MSL timeout. */
2921 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2927 tcp_program_ack (tc0);
2928 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2936 /* 6: check the URG bit TODO */
2938 /* 7: process the segment text */
2941 case TCP_STATE_ESTABLISHED:
2942 case TCP_STATE_FIN_WAIT_1:
2943 case TCP_STATE_FIN_WAIT_2:
2944 if (vnet_buffer (b0)->tcp.data_len)
2945 error0 = tcp_segment_rcv (wrk, tc0, b0);
2947 case TCP_STATE_CLOSE_WAIT:
2948 case TCP_STATE_CLOSING:
2949 case TCP_STATE_LAST_ACK:
2950 case TCP_STATE_TIME_WAIT:
2951 /* This should not occur, since a FIN has been received from the
2952 * remote side. Ignore the segment text. */
2956 /* 8: check the FIN bit */
2960 TCP_EVT (TCP_EVT_FIN_RCVD, tc0);
2964 case TCP_STATE_ESTABLISHED:
2965 /* Account for the FIN and send ack */
2967 tcp_program_ack (tc0);
2968 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2969 tcp_program_disconnect (wrk, tc0);
2970 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
2972 case TCP_STATE_SYN_RCVD:
2973 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2974 * notified yet, set a cleanup timer instead of relying on
2975 * disconnect notify and the implicit close call. */
2976 tcp_connection_timers_reset (tc0);
2979 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2980 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2982 case TCP_STATE_CLOSE_WAIT:
2983 case TCP_STATE_CLOSING:
2984 case TCP_STATE_LAST_ACK:
2987 case TCP_STATE_FIN_WAIT_1:
2990 if (tc0->flags & TCP_CONN_FINPNDG)
2992 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
2993 * sending it. Since we already received a fin, do not wait
2995 tc0->flags |= TCP_CONN_FINRCVD;
2996 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2997 tcp_cfg.closewait_time);
3001 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
3002 tcp_program_ack (tc0);
3003 /* Wait for ACK for our FIN but not forever */
3004 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
3005 tcp_cfg.closing_time);
3008 case TCP_STATE_FIN_WAIT_2:
3009 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
3011 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
3012 tcp_connection_timers_reset (tc0);
3013 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3014 tcp_program_ack (tc0);
3015 session_transport_closed_notify (&tc0->connection);
3017 case TCP_STATE_TIME_WAIT:
3018 /* Remain in the TIME-WAIT state. Restart the time-wait
3021 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3024 error0 = TCP_ERROR_FIN_RCVD;
3028 tcp_inc_counter (rcv_process, error0, 1);
3029 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3031 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3032 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3036 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
3038 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3039 tcp_handle_postponed_dequeues (wrk);
3040 tcp_handle_disconnects (wrk);
3041 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3043 return from_frame->n_vectors;
3046 VLIB_NODE_FN (tcp4_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, 1 /* is_ip4 */ );
3053 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
3054 vlib_node_runtime_t * node,
3055 vlib_frame_t * from_frame)
3057 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3061 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3063 .name = "tcp4-rcv-process",
3064 /* Takes a vector of packets. */
3065 .vector_size = sizeof (u32),
3066 .n_errors = TCP_N_ERROR,
3067 .error_strings = tcp_error_strings,
3068 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3071 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3072 foreach_tcp_state_next
3075 .format_trace = format_tcp_rx_trace_short,
3080 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3082 .name = "tcp6-rcv-process",
3083 /* Takes a vector of packets. */
3084 .vector_size = sizeof (u32),
3085 .n_errors = TCP_N_ERROR,
3086 .error_strings = tcp_error_strings,
3087 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3090 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3091 foreach_tcp_state_next
3094 .format_trace = format_tcp_rx_trace_short,
3099 * LISTEN state processing as per RFC 793 p. 65
3102 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3103 vlib_frame_t * from_frame, int is_ip4)
3105 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3106 u32 my_thread_index = vm->thread_index;
3108 from = first_buffer = vlib_frame_vector_args (from_frame);
3109 n_left_from = from_frame->n_vectors;
3111 while (n_left_from > 0)
3116 tcp_header_t *th0 = 0;
3117 tcp_connection_t *lc0;
3120 tcp_connection_t *child0;
3121 u32 error0 = TCP_ERROR_NONE;
3127 b0 = vlib_get_buffer (vm, bi0);
3128 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3132 ip40 = vlib_buffer_get_current (b0);
3133 th0 = ip4_next_header (ip40);
3137 ip60 = vlib_buffer_get_current (b0);
3138 th0 = ip6_next_header (ip60);
3141 /* Create child session. For syn-flood protection use filter */
3143 /* 1. first check for an RST: handled in dispatch */
3144 /* if (tcp_rst (th0))
3148 /* 2. second check for an ACK: handled in dispatch */
3149 /* if (tcp_ack (th0))
3151 tcp_send_reset (b0, is_ip4);
3156 /* 3. check for a SYN (did that already) */
3158 /* Make sure connection wasn't just created */
3159 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3161 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3163 error0 = TCP_ERROR_CREATE_EXISTS;
3167 /* Create child session and send SYN-ACK */
3168 child0 = tcp_connection_alloc (my_thread_index);
3169 child0->c_lcl_port = th0->dst_port;
3170 child0->c_rmt_port = th0->src_port;
3171 child0->c_is_ip4 = is_ip4;
3172 child0->state = TCP_STATE_SYN_RCVD;
3173 child0->c_fib_index = lc0->c_fib_index;
3174 child0->cc_algo = lc0->cc_algo;
3178 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3179 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3183 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3184 sizeof (ip6_address_t));
3185 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3186 sizeof (ip6_address_t));
3189 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3191 error0 = TCP_ERROR_OPTIONS;
3192 tcp_connection_free (child0);
3196 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3197 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3198 child0->rcv_las = child0->rcv_nxt;
3199 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3201 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3202 * segments are used to initialize PAWS. */
3203 if (tcp_opts_tstamp (&child0->rcv_opts))
3205 child0->tsval_recent = child0->rcv_opts.tsval;
3206 child0->tsval_recent_age = tcp_time_now ();
3209 if (tcp_opts_wscale (&child0->rcv_opts))
3210 child0->snd_wscale = child0->rcv_opts.wscale;
3212 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3213 << child0->snd_wscale;
3214 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3215 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3217 tcp_connection_init_vars (child0);
3218 child0->rto = TCP_RTO_MIN;
3220 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3221 lc0->c_thread_index, 0 /* notify */ ))
3223 tcp_connection_cleanup (child0);
3224 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3228 TCP_EVT (TCP_EVT_SYN_RCVD, child0, 1);
3229 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3230 tcp_send_synack (child0);
3234 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3236 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3237 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3238 clib_memcpy_fast (&t0->tcp_connection, lc0,
3239 sizeof (t0->tcp_connection));
3242 n_syns += (error0 == TCP_ERROR_NONE);
3245 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3246 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3248 return from_frame->n_vectors;
3251 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3252 vlib_frame_t * from_frame)
3254 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3257 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3258 vlib_frame_t * from_frame)
3260 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3264 VLIB_REGISTER_NODE (tcp4_listen_node) =
3266 .name = "tcp4-listen",
3267 /* Takes a vector of packets. */
3268 .vector_size = sizeof (u32),
3269 .n_errors = TCP_N_ERROR,
3270 .error_strings = tcp_error_strings,
3271 .n_next_nodes = TCP_LISTEN_N_NEXT,
3274 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3275 foreach_tcp_state_next
3278 .format_trace = format_tcp_rx_trace_short,
3283 VLIB_REGISTER_NODE (tcp6_listen_node) =
3285 .name = "tcp6-listen",
3286 /* Takes a vector of packets. */
3287 .vector_size = sizeof (u32),
3288 .n_errors = TCP_N_ERROR,
3289 .error_strings = tcp_error_strings,
3290 .n_next_nodes = TCP_LISTEN_N_NEXT,
3293 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3294 foreach_tcp_state_next
3297 .format_trace = format_tcp_rx_trace_short,
3301 typedef enum _tcp_input_next
3303 TCP_INPUT_NEXT_DROP,
3304 TCP_INPUT_NEXT_LISTEN,
3305 TCP_INPUT_NEXT_RCV_PROCESS,
3306 TCP_INPUT_NEXT_SYN_SENT,
3307 TCP_INPUT_NEXT_ESTABLISHED,
3308 TCP_INPUT_NEXT_RESET,
3309 TCP_INPUT_NEXT_PUNT,
3313 #define foreach_tcp4_input_next \
3314 _ (DROP, "ip4-drop") \
3315 _ (LISTEN, "tcp4-listen") \
3316 _ (RCV_PROCESS, "tcp4-rcv-process") \
3317 _ (SYN_SENT, "tcp4-syn-sent") \
3318 _ (ESTABLISHED, "tcp4-established") \
3319 _ (RESET, "tcp4-reset") \
3320 _ (PUNT, "ip4-punt")
3322 #define foreach_tcp6_input_next \
3323 _ (DROP, "ip6-drop") \
3324 _ (LISTEN, "tcp6-listen") \
3325 _ (RCV_PROCESS, "tcp6-rcv-process") \
3326 _ (SYN_SENT, "tcp6-syn-sent") \
3327 _ (ESTABLISHED, "tcp6-established") \
3328 _ (RESET, "tcp6-reset") \
3329 _ (PUNT, "ip6-punt")
3331 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3334 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3335 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3337 tcp_connection_t *tc;
3342 for (i = 0; i < n_bufs; i++)
3344 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3346 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3347 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3349 tcp = vlib_buffer_get_current (bs[i]);
3350 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3356 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3358 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3360 *next = TCP_INPUT_NEXT_DROP;
3362 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3364 *next = TCP_INPUT_NEXT_PUNT;
3365 *error = TCP_ERROR_PUNT;
3369 *next = TCP_INPUT_NEXT_RESET;
3370 *error = TCP_ERROR_NO_LISTENER;
3374 always_inline tcp_connection_t *
3375 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3376 u8 is_ip4, u8 is_nolookup)
3378 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3379 int n_advance_bytes, n_data_bytes;
3380 transport_connection_t *tc;
3386 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3387 int ip_hdr_bytes = ip4_header_bytes (ip4);
3388 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3390 *error = TCP_ERROR_LENGTH;
3393 tcp = ip4_next_header (ip4);
3394 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3395 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3396 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3398 /* Length check. Checksum computed by ipx_local no need to compute again */
3399 if (PREDICT_FALSE (n_data_bytes < 0))
3401 *error = TCP_ERROR_LENGTH;
3406 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3407 &ip4->src_address, tcp->dst_port,
3409 TRANSPORT_PROTO_TCP, thread_index,
3414 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3415 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3417 *error = TCP_ERROR_LENGTH;
3420 tcp = ip6_next_header (ip6);
3421 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3422 n_advance_bytes = tcp_header_bytes (tcp);
3423 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3425 n_advance_bytes += sizeof (ip6[0]);
3427 if (PREDICT_FALSE (n_data_bytes < 0))
3429 *error = TCP_ERROR_LENGTH;
3436 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3438 ip4_main_t *im = &ip4_main;
3439 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3440 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3443 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3445 tcp->dst_port, tcp->src_port,
3446 TRANSPORT_PROTO_TCP,
3447 thread_index, &result);
3453 (transport_connection_t *) tcp_connection_get (vnet_buffer (b)->
3454 tcp.connection_index,
3457 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3458 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3459 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3460 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3461 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3463 vnet_buffer (b)->tcp.flags = 0;
3465 *error = result ? TCP_ERROR_NONE + result : *error;
3467 return tcp_get_connection_from_transport (tc);
3471 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3472 vlib_buffer_t * b, u16 * next, u32 * error)
3477 tcp = tcp_buffer_hdr (b);
3478 flags = tcp->flags & filter_flags;
3479 *next = tm->dispatch_table[tc->state][flags].next;
3480 *error = tm->dispatch_table[tc->state][flags].error;
3483 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3484 || *next == TCP_INPUT_NEXT_RESET))
3486 /* Overload tcp flags to store state */
3487 tcp_state_t state = tc->state;
3488 vnet_buffer (b)->tcp.flags = tc->state;
3490 if (*error == TCP_ERROR_DISPATCH)
3491 clib_warning ("tcp conn %u disp error state %U flags %U",
3492 tc->c_c_index, format_tcp_state, state,
3493 format_tcp_flags, (int) flags);
3498 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3499 vlib_frame_t * frame, int is_ip4, u8 is_nolookup)
3501 u32 n_left_from, *from, thread_index = vm->thread_index;
3502 tcp_main_t *tm = vnet_get_tcp_main ();
3503 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3504 u16 nexts[VLIB_FRAME_SIZE], *next;
3506 tcp_set_time_now (tcp_get_worker (thread_index));
3508 from = vlib_frame_vector_args (frame);
3509 n_left_from = frame->n_vectors;
3510 vlib_get_buffers (vm, from, bufs, n_left_from);
3515 while (n_left_from >= 4)
3517 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3518 tcp_connection_t *tc0, *tc1;
3521 vlib_prefetch_buffer_header (b[2], STORE);
3522 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3524 vlib_prefetch_buffer_header (b[3], STORE);
3525 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3528 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3530 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3532 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4,
3535 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3537 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3538 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3540 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3541 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3543 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3544 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3548 if (PREDICT_TRUE (tc0 != 0))
3550 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3551 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3552 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3555 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3557 if (PREDICT_TRUE (tc1 != 0))
3559 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3560 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3561 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3564 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3571 while (n_left_from > 0)
3573 tcp_connection_t *tc0;
3574 u32 error0 = TCP_ERROR_NO_LISTENER;
3576 if (n_left_from > 1)
3578 vlib_prefetch_buffer_header (b[1], STORE);
3579 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3582 next[0] = TCP_INPUT_NEXT_DROP;
3583 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3585 if (PREDICT_TRUE (tc0 != 0))
3587 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3588 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3589 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3592 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3599 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3600 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3602 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3603 return frame->n_vectors;
3606 VLIB_NODE_FN (tcp4_input_nolookup_node) (vlib_main_t * vm,
3607 vlib_node_runtime_t * node,
3608 vlib_frame_t * from_frame)
3610 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3611 1 /* is_nolookup */ );
3614 VLIB_NODE_FN (tcp6_input_nolookup_node) (vlib_main_t * vm,
3615 vlib_node_runtime_t * node,
3616 vlib_frame_t * from_frame)
3618 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3619 1 /* is_nolookup */ );
3623 VLIB_REGISTER_NODE (tcp4_input_nolookup_node) =
3625 .name = "tcp4-input-nolookup",
3626 /* Takes a vector of packets. */
3627 .vector_size = sizeof (u32),
3628 .n_errors = TCP_N_ERROR,
3629 .error_strings = tcp_error_strings,
3630 .n_next_nodes = TCP_INPUT_N_NEXT,
3633 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3634 foreach_tcp4_input_next
3637 .format_buffer = format_tcp_header,
3638 .format_trace = format_tcp_rx_trace,
3643 VLIB_REGISTER_NODE (tcp6_input_nolookup_node) =
3645 .name = "tcp6-input-nolookup",
3646 /* Takes a vector of packets. */
3647 .vector_size = sizeof (u32),
3648 .n_errors = TCP_N_ERROR,
3649 .error_strings = tcp_error_strings,
3650 .n_next_nodes = TCP_INPUT_N_NEXT,
3653 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3654 foreach_tcp6_input_next
3657 .format_buffer = format_tcp_header,
3658 .format_trace = format_tcp_rx_trace,
3662 VLIB_NODE_FN (tcp4_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, 1 /* is_ip4 */ ,
3666 0 /* is_nolookup */ );
3669 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3670 vlib_frame_t * from_frame)
3672 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3673 0 /* is_nolookup */ );
3677 VLIB_REGISTER_NODE (tcp4_input_node) =
3679 .name = "tcp4-input",
3680 /* Takes a vector of packets. */
3681 .vector_size = sizeof (u32),
3682 .n_errors = TCP_N_ERROR,
3683 .error_strings = tcp_error_strings,
3684 .n_next_nodes = TCP_INPUT_N_NEXT,
3687 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3688 foreach_tcp4_input_next
3691 .format_buffer = format_tcp_header,
3692 .format_trace = format_tcp_rx_trace,
3697 VLIB_REGISTER_NODE (tcp6_input_node) =
3699 .name = "tcp6-input",
3700 /* Takes a vector of packets. */
3701 .vector_size = sizeof (u32),
3702 .n_errors = TCP_N_ERROR,
3703 .error_strings = tcp_error_strings,
3704 .n_next_nodes = TCP_INPUT_N_NEXT,
3707 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3708 foreach_tcp6_input_next
3711 .format_buffer = format_tcp_header,
3712 .format_trace = format_tcp_rx_trace,
3716 #ifndef CLIB_MARCH_VARIANT
3718 tcp_dispatch_table_init (tcp_main_t * tm)
3721 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3722 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3724 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3725 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3728 #define _(t,f,n,e) \
3730 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3731 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3734 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3735 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3736 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3737 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3738 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3739 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3740 TCP_ERROR_ACK_INVALID);
3741 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3742 TCP_ERROR_SEGMENT_INVALID);
3743 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3744 TCP_ERROR_SEGMENT_INVALID);
3745 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3746 TCP_ERROR_INVALID_CONNECTION);
3747 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3748 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3749 TCP_ERROR_SEGMENT_INVALID);
3750 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3751 TCP_ERROR_SEGMENT_INVALID);
3752 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3754 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3755 TCP_ERROR_SEGMENT_INVALID);
3756 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3757 TCP_ERROR_SEGMENT_INVALID);
3758 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3759 TCP_ERROR_SEGMENT_INVALID);
3760 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3761 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3762 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3763 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3764 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3765 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3767 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3768 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3770 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3772 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3773 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3774 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3775 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3777 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3779 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3780 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3781 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3783 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3784 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3785 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3786 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3787 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3788 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3789 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3790 /* SYN-ACK for a SYN */
3791 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3793 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3794 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3795 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3797 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3798 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3800 /* ACK for for established connection -> tcp-established. */
3801 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3802 /* FIN for for established connection -> tcp-established. */
3803 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3804 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3806 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3808 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3809 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3810 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3812 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3813 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3814 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3815 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3816 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3817 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3818 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3819 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3821 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3822 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3824 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3826 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3827 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3828 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3829 /* ACK or FIN-ACK to our FIN */
3830 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3831 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3833 /* FIN in reply to our FIN from the other side */
3834 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3835 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3836 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3838 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3839 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3840 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3841 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3842 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3843 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3844 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3846 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3847 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3848 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3849 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3851 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3853 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3854 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3855 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3856 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3858 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3859 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3860 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3861 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3863 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3865 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3866 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3867 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3868 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3870 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3871 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3873 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3875 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3876 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3877 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3879 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3880 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3881 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3882 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3883 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3884 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3885 /* FIN confirming that the peer (app) has closed */
3886 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3887 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3888 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3890 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3891 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3893 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3894 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3896 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3897 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3899 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3900 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3901 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3902 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3904 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3906 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3907 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3908 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3910 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3911 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3912 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3913 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3914 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3915 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3916 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3917 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3919 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3920 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3922 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3924 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3925 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3926 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3927 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3928 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3930 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3931 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3933 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3934 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3935 * incoming segment not containing a RST causes a RST to be sent in
3937 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3938 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3939 TCP_ERROR_CONNECTION_CLOSED);
3940 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3941 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3942 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3947 static clib_error_t *
3948 tcp_input_init (vlib_main_t * vm)
3950 clib_error_t *error = 0;
3951 tcp_main_t *tm = vnet_get_tcp_main ();
3953 if ((error = vlib_call_init_function (vm, tcp_init)))
3956 /* Initialize dispatch table. */
3957 tcp_dispatch_table_init (tm);
3962 VLIB_INIT_FUNCTION (tcp_input_init);
3964 #endif /* CLIB_MARCH_VARIANT */
3967 * fd.io coding-style-patch-verification: ON
3970 * eval: (c-set-style "gnu")