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 + tc->sack_sb.snd_una_adv;
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
785 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
787 sack_scoreboard_hole_t *left, *right;
788 u32 bytes = 0, blks = 0;
790 sb->last_lost_bytes = 0;
792 sb->sacked_bytes = 0;
793 left = scoreboard_last_hole (sb);
797 if (seq_gt (sb->high_sacked, left->end))
799 bytes = sb->high_sacked - left->end;
803 while ((right = left)
804 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
805 && blks < TCP_DUPACK_THRESHOLD
806 /* left not updated if above conditions fail */
807 && (left = scoreboard_prev_hole (sb, right)))
809 bytes += right->start - left->end;
813 /* left is first lost */
818 sb->lost_bytes += scoreboard_hole_bytes (right);
819 sb->last_lost_bytes += left->is_lost ? 0 : left->end - left->start;
821 left = scoreboard_prev_hole (sb, right);
823 bytes += right->start - left->end;
825 while ((right = left));
828 sb->sacked_bytes = bytes;
832 * Figure out the next hole to retransmit
834 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
836 sack_scoreboard_hole_t *
837 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
838 sack_scoreboard_hole_t * start,
839 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
841 sack_scoreboard_hole_t *hole = 0;
843 hole = start ? start : scoreboard_first_hole (sb);
844 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
845 hole = scoreboard_next_hole (sb, hole);
847 /* Nothing, return */
850 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
854 /* Rule (1): if higher than rxt, less than high_sacked and lost */
855 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
857 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
861 /* Rule (2): available unsent data */
864 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
867 /* Rule (3): if hole not lost */
868 else if (seq_lt (hole->start, sb->high_sacked))
871 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
873 /* Rule (4): if hole beyond high_sacked */
876 ASSERT (seq_geq (hole->start, sb->high_sacked));
879 /* HighRxt MUST NOT be updated */
884 if (hole && seq_lt (sb->high_rxt, hole->start))
885 sb->high_rxt = hole->start;
889 #endif /* CLIB_MARCH_VARIANT */
892 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
894 sack_scoreboard_hole_t *hole;
895 hole = scoreboard_first_hole (sb);
898 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
899 sb->cur_rxt_hole = sb->head;
901 sb->high_rxt = snd_una;
902 sb->rescue_rxt = snd_una - 1;
905 #ifndef CLIB_MARCH_VARIANT
907 scoreboard_init (sack_scoreboard_t * sb)
909 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
910 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
911 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
915 scoreboard_clear (sack_scoreboard_t * sb)
917 sack_scoreboard_hole_t *hole;
918 while ((hole = scoreboard_first_hole (sb)))
920 scoreboard_remove_hole (sb, hole);
922 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
923 ASSERT (pool_elts (sb->holes) == 0);
924 sb->sacked_bytes = 0;
925 sb->last_sacked_bytes = 0;
926 sb->last_bytes_delivered = 0;
931 sb->last_lost_bytes = 0;
932 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
934 #endif /* CLIB_MARCH_VARIANT */
937 * Test that scoreboard is sane after recovery
939 * Returns 1 if scoreboard is empty or if first hole beyond
943 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
945 sack_scoreboard_hole_t *hole;
946 hole = scoreboard_first_hole (&tc->sack_sb);
947 return (!hole || (seq_geq (hole->start, tc->snd_una)
948 && seq_lt (hole->end, tc->snd_nxt)));
951 #ifndef CLIB_MARCH_VARIANT
954 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
956 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
957 u32 blk_index = 0, old_sacked_bytes, hole_index;
958 sack_scoreboard_t *sb = &tc->sack_sb;
959 sack_block_t *blk, tmp;
962 sb->last_sacked_bytes = 0;
963 sb->last_bytes_delivered = 0;
966 if (!tcp_opts_sack (&tc->rcv_opts)
967 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
970 old_sacked_bytes = sb->sacked_bytes;
972 /* Remove invalid blocks */
973 blk = tc->rcv_opts.sacks;
974 while (blk < vec_end (tc->rcv_opts.sacks))
976 if (seq_lt (blk->start, blk->end)
977 && seq_gt (blk->start, tc->snd_una)
978 && seq_gt (blk->start, ack)
979 && seq_lt (blk->start, tc->snd_nxt)
980 && seq_leq (blk->end, tc->snd_nxt))
985 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
988 /* Add block for cumulative ack */
989 if (seq_gt (ack, tc->snd_una))
991 tmp.start = tc->snd_una;
993 vec_add1 (tc->rcv_opts.sacks, tmp);
996 if (vec_len (tc->rcv_opts.sacks) == 0)
999 tcp_scoreboard_trace_add (tc, ack);
1001 /* Make sure blocks are ordered */
1002 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
1003 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
1004 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
1006 tmp = tc->rcv_opts.sacks[i];
1007 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
1008 tc->rcv_opts.sacks[j] = tmp;
1011 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1013 /* If no holes, insert the first that covers all outstanding bytes */
1014 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1015 tc->snd_una, tc->snd_nxt);
1016 sb->tail = scoreboard_hole_index (sb, last_hole);
1017 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
1018 sb->high_sacked = tmp.end;
1022 /* If we have holes but snd_una_max is beyond the last hole, update
1024 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
1025 last_hole = scoreboard_last_hole (sb);
1026 if (seq_gt (tc->snd_nxt, last_hole->end))
1028 if (seq_geq (last_hole->start, sb->high_sacked))
1030 last_hole->end = tc->snd_nxt;
1032 /* New hole after high sacked block */
1033 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1035 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1039 /* Keep track of max byte sacked for when the last hole
1041 if (seq_gt (tmp.end, sb->high_sacked))
1042 sb->high_sacked = tmp.end;
1045 /* Walk the holes with the SACK blocks */
1046 hole = pool_elt_at_index (sb->holes, sb->head);
1047 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
1049 blk = &tc->rcv_opts.sacks[blk_index];
1050 if (seq_leq (blk->start, hole->start))
1052 /* Block covers hole. Remove hole */
1053 if (seq_geq (blk->end, hole->end))
1055 next_hole = scoreboard_next_hole (sb, hole);
1057 /* Byte accounting: snd_una needs to be advanced */
1058 if (blk->end == ack)
1062 if (seq_lt (ack, next_hole->start))
1063 sb->snd_una_adv = next_hole->start - ack;
1064 sb->last_bytes_delivered +=
1065 next_hole->start - hole->end;
1069 ASSERT (seq_geq (sb->high_sacked, ack));
1070 sb->snd_una_adv = sb->high_sacked - ack;
1071 sb->last_bytes_delivered += sb->high_sacked - hole->end;
1074 scoreboard_remove_hole (sb, hole);
1077 /* Partial 'head' overlap */
1080 if (seq_gt (blk->end, hole->start))
1082 hole->start = blk->end;
1089 /* Hole must be split */
1090 if (seq_lt (blk->end, hole->end))
1092 hole_index = scoreboard_hole_index (sb, hole);
1093 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1096 /* Pool might've moved */
1097 hole = scoreboard_get_hole (sb, hole_index);
1098 hole->end = blk->start;
1100 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1102 else if (seq_lt (blk->start, hole->end))
1104 hole->end = blk->start;
1106 hole = scoreboard_next_hole (sb, hole);
1110 if (pool_elts (sb->holes) == 1)
1112 hole = scoreboard_first_hole (sb);
1113 if (hole->start == ack + sb->snd_una_adv && hole->end == tc->snd_nxt)
1114 scoreboard_remove_hole (sb, hole);
1117 scoreboard_update_bytes (tc, sb);
1118 sb->last_sacked_bytes = sb->sacked_bytes
1119 - (old_sacked_bytes - sb->last_bytes_delivered);
1121 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1122 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1123 || sb->sacked_bytes < tc->snd_nxt - seq_max (tc->snd_una, ack));
1124 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1125 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1126 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1127 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1128 ASSERT (sb->last_lost_bytes <= sb->lost_bytes);
1130 TCP_EVT (TCP_EVT_CC_SCOREBOARD, tc);
1132 #endif /* CLIB_MARCH_VARIANT */
1135 * Try to update snd_wnd based on feedback received from peer.
1137 * If successful, and new window is 'effectively' 0, activate persist
1141 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1143 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1144 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1145 if (seq_lt (tc->snd_wl1, seq)
1146 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1148 tc->snd_wnd = snd_wnd;
1151 TCP_EVT (TCP_EVT_SND_WND, tc);
1153 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1155 /* Set persist timer if not set and we just got 0 wnd */
1156 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1157 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1158 tcp_persist_timer_set (tc);
1162 tcp_persist_timer_reset (tc);
1163 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1166 tcp_update_rto (tc);
1172 #ifndef CLIB_MARCH_VARIANT
1174 * Init loss recovery/fast recovery.
1176 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1177 * updated in @ref tcp_cc_handle_event after fast retransmit
1180 tcp_cc_init_congestion (tcp_connection_t * tc)
1182 tcp_fastrecovery_on (tc);
1183 tc->snd_congestion = tc->snd_nxt;
1184 tc->cwnd_acc_bytes = 0;
1185 tc->snd_rxt_bytes = 0;
1186 tc->prev_ssthresh = tc->ssthresh;
1187 tc->prev_cwnd = tc->cwnd;
1188 tc->cc_algo->congestion (tc);
1189 tc->fr_occurences += 1;
1190 TCP_EVT (TCP_EVT_CC_EVT, tc, 4);
1192 #endif /* CLIB_MARCH_VARIANT */
1195 tcp_cc_recovery_exit (tcp_connection_t * tc)
1198 tcp_update_rto (tc);
1201 tcp_recovery_off (tc);
1202 TCP_EVT (TCP_EVT_CC_EVT, tc, 3);
1205 #ifndef CLIB_MARCH_VARIANT
1207 tcp_cc_fastrecovery_clear (tcp_connection_t * tc)
1209 tc->snd_rxt_bytes = 0;
1210 tc->rcv_dupacks = 0;
1213 tcp_fastrecovery_off (tc);
1214 tcp_fastrecovery_first_off (tc);
1215 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1217 TCP_EVT (TCP_EVT_CC_EVT, tc, 3);
1219 #endif /* CLIB_MARCH_VARIANT */
1222 tcp_cc_congestion_undo (tcp_connection_t * tc)
1224 tc->cwnd = tc->prev_cwnd;
1225 tc->ssthresh = tc->prev_ssthresh;
1226 tc->rcv_dupacks = 0;
1227 if (tcp_in_recovery (tc))
1229 tcp_cc_recovery_exit (tc);
1230 tc->snd_nxt = seq_max (tc->snd_nxt, tc->snd_congestion);
1232 else if (tcp_in_fastrecovery (tc))
1234 tcp_cc_fastrecovery_clear (tc);
1236 tcp_cc_undo_recovery (tc);
1237 ASSERT (tc->rto_boff == 0);
1238 TCP_EVT (TCP_EVT_CC_EVT, tc, 5);
1242 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1244 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1246 && tcp_opts_tstamp (&tc->rcv_opts)
1247 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1251 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1253 return (tcp_in_fastrecovery (tc)
1254 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1258 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1260 return (tcp_cc_is_spurious_timeout_rxt (tc)
1261 || tcp_cc_is_spurious_fast_rxt (tc));
1265 tcp_cc_recover (tcp_connection_t * tc)
1267 ASSERT (tcp_in_cong_recovery (tc));
1268 if (tcp_cc_is_spurious_retransmit (tc))
1270 tcp_cc_congestion_undo (tc);
1274 if (tcp_in_recovery (tc))
1275 tcp_cc_recovery_exit (tc);
1276 else if (tcp_in_fastrecovery (tc))
1278 tcp_cc_recovered (tc);
1279 tcp_cc_fastrecovery_clear (tc);
1282 ASSERT (tc->rto_boff == 0);
1283 ASSERT (!tcp_in_cong_recovery (tc));
1284 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1289 tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1291 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1293 /* Congestion avoidance */
1294 tcp_cc_rcv_ack (tc, rs);
1296 /* If a cumulative ack, make sure dupacks is 0 */
1297 tc->rcv_dupacks = 0;
1299 /* When dupacks hits the threshold we only enter fast retransmit if
1300 * cumulative ack covers more than snd_congestion. Should snd_una
1301 * wrap this test may fail under otherwise valid circumstances.
1302 * Therefore, proactively update snd_congestion when wrap detected. */
1304 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1305 && seq_gt (tc->snd_congestion, tc->snd_una)))
1306 tc->snd_congestion = tc->snd_una - 1;
1310 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1312 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1316 tcp_should_fastrecover (tcp_connection_t * tc)
1318 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1319 || tcp_should_fastrecover_sack (tc));
1323 * One function to rule them all ... and in the darkness bind them
1326 tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs,
1331 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1333 if (tc->bytes_acked)
1335 tcp_program_fastretransmit (tc);
1339 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1340 * it account for the bytes that left the network.
1342 else if (is_dack && !tcp_in_recovery (tc))
1344 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1345 ASSERT (tc->snd_una != tc->snd_nxt || tc->sack_sb.last_sacked_bytes);
1349 /* Pure duplicate ack. If some data got acked, it's handled lower */
1350 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1352 ASSERT (tcp_in_fastrecovery (tc));
1353 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1356 else if (tcp_should_fastrecover (tc))
1360 ASSERT (!tcp_in_fastrecovery (tc));
1362 /* Heuristic to catch potential late dupacks
1363 * after fast retransmit exits */
1364 if (is_dack && tc->snd_una == tc->snd_congestion
1365 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1367 tc->rcv_dupacks = 0;
1371 tcp_cc_init_congestion (tc);
1373 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1374 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1376 /* Constrain rate until we get a partial ack */
1377 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1378 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1379 0 /* start bucket */ );
1380 tcp_program_fastretransmit (tc);
1383 else if (!tc->bytes_acked
1384 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1386 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1392 /* Don't allow entry in fast recovery if still in recovery, for now */
1393 else if (0 && is_dack && tcp_in_recovery (tc))
1395 /* If of of the two conditions lower hold, reset dupacks because
1396 * we're probably after timeout (RFC6582 heuristics).
1397 * If Cumulative ack does not cover more than congestion threshold,
1399 * 1) The following doesn't hold: The congestion window is greater
1400 * than SMSS bytes and the difference between highest_ack
1401 * and prev_highest_ack is at most 4*SMSS bytes
1402 * 2) Echoed timestamp in the last non-dup ack does not equal the
1405 if (seq_leq (tc->snd_una, tc->snd_congestion)
1406 && ((!(tc->cwnd > tc->snd_mss
1407 && tc->bytes_acked <= 4 * tc->snd_mss))
1408 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1410 tc->rcv_dupacks = 0;
1415 if (!tc->bytes_acked)
1419 TCP_EVT (TCP_EVT_CC_PACK, tc);
1422 * Legitimate ACK. 1) See if we can exit recovery
1425 /* Update the pacing rate. For the first partial ack we move from
1426 * the artificially constrained rate to the one after congestion */
1427 tcp_connection_tx_pacer_update (tc);
1429 if (seq_geq (tc->snd_una, tc->snd_congestion))
1431 tcp_retransmit_timer_update (tc);
1433 /* If spurious return, we've already updated everything */
1434 if (tcp_cc_recover (tc))
1436 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1440 /* Treat as congestion avoidance ack */
1441 tcp_cc_rcv_ack (tc, rs);
1446 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1449 /* XXX limit this only to first partial ack? */
1450 tcp_retransmit_timer_update (tc);
1452 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1453 * reset dupacks to 0. Also needed if in congestion recovery */
1454 tc->rcv_dupacks = 0;
1456 /* Post RTO timeout don't try anything fancy */
1457 if (tcp_in_recovery (tc))
1459 tcp_cc_rcv_ack (tc, rs);
1460 transport_add_tx_event (&tc->connection);
1464 /* Remove retransmitted bytes that have been delivered */
1465 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1467 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1468 >= tc->sack_sb.last_bytes_delivered
1469 || (tc->flags & TCP_CONN_FINSNT));
1471 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1472 * remove sacked bytes delivered */
1473 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1475 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1476 - tc->sack_sb.last_bytes_delivered;
1477 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1478 tc->snd_rxt_bytes -= rxt_delivered;
1482 /* Apparently all retransmitted holes have been acked */
1483 tc->snd_rxt_bytes = 0;
1484 tc->sack_sb.high_rxt = tc->snd_una;
1489 tcp_fastrecovery_first_on (tc);
1490 if (tc->snd_rxt_bytes > tc->bytes_acked)
1491 tc->snd_rxt_bytes -= tc->bytes_acked;
1493 tc->snd_rxt_bytes = 0;
1496 tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs);
1499 * Since this was a partial ack, try to retransmit some more data
1501 tcp_program_fastretransmit (tc);
1505 * Process incoming ACK
1508 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1509 tcp_header_t * th, u32 * error)
1511 u32 prev_snd_wnd, prev_snd_una;
1512 tcp_rate_sample_t rs = { 0 };
1515 TCP_EVT (TCP_EVT_CC_STAT, tc);
1517 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1518 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1520 /* We've probably entered recovery and the peer still has some
1521 * of the data we've sent. Update snd_nxt and accept the ack */
1522 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1523 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1525 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1529 tc->errors.above_ack_wnd += 1;
1530 *error = TCP_ERROR_ACK_FUTURE;
1531 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 0, vnet_buffer (b)->tcp.ack_number);
1535 /* If old ACK, probably it's an old dupack */
1536 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1538 tc->errors.below_ack_wnd += 1;
1539 *error = TCP_ERROR_ACK_OLD;
1540 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 1, vnet_buffer (b)->tcp.ack_number);
1541 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1542 tcp_cc_handle_event (tc, 0, 1);
1543 /* Don't drop yet */
1550 * Looks okay, process feedback
1553 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1554 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1556 prev_snd_wnd = tc->snd_wnd;
1557 prev_snd_una = tc->snd_una;
1558 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1559 vnet_buffer (b)->tcp.ack_number,
1560 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1561 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1562 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1563 tcp_validate_txf_size (tc, tc->bytes_acked);
1565 if (tc->bytes_acked)
1567 tcp_program_dequeue (wrk, tc);
1568 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1571 if (tc->flags & TCP_CONN_RATE_SAMPLE)
1572 tcp_bt_sample_delivery_rate (tc, &rs);
1574 TCP_EVT (TCP_EVT_ACK_RCVD, tc);
1577 * Check if we have congestion event
1580 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1582 tcp_cc_handle_event (tc, &rs, is_dack);
1583 tc->dupacks_in += is_dack;
1584 if (!tcp_in_cong_recovery (tc))
1586 *error = TCP_ERROR_ACK_OK;
1589 *error = TCP_ERROR_ACK_DUP;
1590 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1596 * Update congestion control (slow start/congestion avoidance)
1598 tcp_cc_update (tc, &rs);
1599 *error = TCP_ERROR_ACK_OK;
1604 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1606 if (!tcp_disconnect_pending (tc))
1608 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1609 tcp_disconnect_pending_on (tc);
1614 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1616 u32 thread_index, *pending_disconnects;
1617 tcp_connection_t *tc;
1620 if (!vec_len (wrk->pending_disconnects))
1623 thread_index = wrk->vm->thread_index;
1624 pending_disconnects = wrk->pending_disconnects;
1625 for (i = 0; i < vec_len (pending_disconnects); i++)
1627 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1628 tcp_disconnect_pending_off (tc);
1629 session_transport_closing_notify (&tc->connection);
1631 _vec_len (wrk->pending_disconnects) = 0;
1635 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1638 /* Reject out-of-order fins */
1639 if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt)
1642 /* Account for the FIN and send ack */
1644 tcp_program_ack (tc);
1645 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1646 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1647 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1648 tcp_program_disconnect (wrk, tc);
1649 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
1650 TCP_EVT (TCP_EVT_FIN_RCVD, tc);
1651 *error = TCP_ERROR_FIN_RCVD;
1654 #ifndef CLIB_MARCH_VARIANT
1656 tcp_sack_vector_is_sane (sack_block_t * sacks)
1659 for (i = 1; i < vec_len (sacks); i++)
1661 if (sacks[i - 1].end == sacks[i].start)
1668 * Build SACK list as per RFC2018.
1670 * Makes sure the first block contains the segment that generated the current
1671 * ACK and the following ones are the ones most recently reported in SACK
1674 * @param tc TCP connection for which the SACK list is updated
1675 * @param start Start sequence number of the newest SACK block
1676 * @param end End sequence of the newest SACK block
1679 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1681 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1684 /* If the first segment is ooo add it to the list. Last write might've moved
1685 * rcv_nxt over the first segment. */
1686 if (seq_lt (tc->rcv_nxt, start))
1688 vec_add2 (new_list, block, 1);
1689 block->start = start;
1693 /* Find the blocks still worth keeping. */
1694 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1696 /* Discard if rcv_nxt advanced beyond current block */
1697 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1700 /* Merge or drop if segment overlapped by the new segment */
1701 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1702 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1704 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1705 new_list[0].start = tc->snd_sacks[i].start;
1706 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1707 new_list[0].end = tc->snd_sacks[i].end;
1711 /* Save to new SACK list if we have space. */
1712 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1713 vec_add1 (new_list, tc->snd_sacks[i]);
1716 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1718 /* Replace old vector with new one */
1719 vec_reset_length (tc->snd_sacks);
1720 tc->snd_sacks_fl = tc->snd_sacks;
1721 tc->snd_sacks = new_list;
1723 /* Segments should not 'touch' */
1724 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1728 tcp_sack_list_bytes (tcp_connection_t * tc)
1731 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1732 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1735 #endif /* CLIB_MARCH_VARIANT */
1737 /** Enqueue data for delivery to application */
1739 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1742 int written, error = TCP_ERROR_ENQUEUED;
1744 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1746 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1747 1 /* queue event */ , 1);
1748 tc->bytes_in += written;
1750 TCP_EVT (TCP_EVT_INPUT, tc, 0, data_len, written);
1752 /* Update rcv_nxt */
1753 if (PREDICT_TRUE (written == data_len))
1755 tc->rcv_nxt += written;
1757 /* If more data written than expected, account for out-of-order bytes. */
1758 else if (written > data_len)
1760 tc->rcv_nxt += written;
1761 TCP_EVT (TCP_EVT_CC_INPUT, tc, data_len, written);
1763 else if (written > 0)
1765 /* We've written something but FIFO is probably full now */
1766 tc->rcv_nxt += written;
1767 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1771 return TCP_ERROR_FIFO_FULL;
1774 /* Update SACK list if need be */
1775 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1777 /* Remove SACK blocks that have been delivered */
1778 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1784 /** Enqueue out-of-order data */
1786 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1792 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1795 /* Enqueue out-of-order data with relative offset */
1796 rv = session_enqueue_stream_connection (&tc->connection, b,
1797 vnet_buffer (b)->tcp.seq_number -
1798 tc->rcv_nxt, 0 /* queue event */ ,
1801 /* Nothing written */
1804 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, 0);
1805 return TCP_ERROR_FIFO_FULL;
1808 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1809 tc->bytes_in += data_len;
1811 /* Update SACK list if in use */
1812 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1814 ooo_segment_t *newest;
1817 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1819 /* Get the newest segment from the fifo */
1820 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1823 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1824 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1825 start = tc->rcv_nxt + offset;
1826 end = start + ooo_segment_length (s0->rx_fifo, newest);
1827 tcp_update_sack_list (tc, start, end);
1828 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1829 TCP_EVT (TCP_EVT_CC_SACKS, tc);
1833 return TCP_ERROR_ENQUEUED_OOO;
1837 * Check if ACK could be delayed. If ack can be delayed, it should return
1838 * true for a full frame. If we're always acking return 0.
1841 tcp_can_delack (tcp_connection_t * tc)
1843 /* Send ack if ... */
1845 /* just sent a rcv wnd 0
1846 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1847 /* constrained to send ack */
1848 || (tc->flags & TCP_CONN_SNDACK) != 0
1849 /* we're almost out of tx wnd */
1850 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1857 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1859 u32 discard, first = b->current_length;
1860 vlib_main_t *vm = vlib_get_main ();
1862 /* Handle multi-buffer segments */
1863 if (n_bytes_to_drop > b->current_length)
1865 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1869 discard = clib_min (n_bytes_to_drop, b->current_length);
1870 vlib_buffer_advance (b, discard);
1871 b = vlib_get_buffer (vm, b->next_buffer);
1872 n_bytes_to_drop -= discard;
1874 while (n_bytes_to_drop);
1875 if (n_bytes_to_drop > first)
1876 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1879 vlib_buffer_advance (b, n_bytes_to_drop);
1880 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1885 * Receive buffer for connection and handle acks
1887 * It handles both in order or out-of-order data.
1890 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1893 u32 error, n_bytes_to_drop, n_data_bytes;
1895 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1896 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1897 ASSERT (n_data_bytes);
1898 tc->data_segs_in += 1;
1900 /* Handle out-of-order data */
1901 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1903 /* Old sequence numbers allowed through because they overlapped
1905 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1907 /* Completely in the past (possible retransmit). Ack
1908 * retransmissions since we may not have any data to send */
1909 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1911 tcp_program_ack (tc);
1912 error = TCP_ERROR_SEGMENT_OLD;
1916 /* Chop off the bytes in the past and see if what is left
1917 * can be enqueued in order */
1918 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1919 n_data_bytes -= n_bytes_to_drop;
1920 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1921 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1923 error = TCP_ERROR_SEGMENT_OLD;
1929 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1930 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1931 tcp_program_dupack (tc);
1932 TCP_EVT (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1933 tc->errors.above_data_wnd += seq_gt (vnet_buffer (b)->tcp.seq_end,
1934 tc->rcv_las + tc->rcv_wnd);
1940 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1941 * segments can be enqueued after fifo tail offset changes. */
1942 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1943 if (tcp_can_delack (tc))
1945 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1946 tcp_timer_set (tc, TCP_TIMER_DELACK, tcp_cfg.delack_time);
1950 tcp_program_ack (tc);
1958 tcp_header_t tcp_header;
1959 tcp_connection_t tcp_connection;
1963 format_tcp_rx_trace (u8 * s, va_list * args)
1965 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1966 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1967 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1968 u32 indent = format_get_indent (s);
1970 s = format (s, "%U\n%U%U",
1971 format_tcp_header, &t->tcp_header, 128,
1972 format_white_space, indent,
1973 format_tcp_connection, &t->tcp_connection, 1);
1979 format_tcp_rx_trace_short (u8 * s, va_list * args)
1981 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1982 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1983 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1985 s = format (s, "%d -> %d (%U)",
1986 clib_net_to_host_u16 (t->tcp_header.dst_port),
1987 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1988 t->tcp_connection.state);
1994 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1995 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1999 clib_memcpy_fast (&t0->tcp_connection, tc0,
2000 sizeof (t0->tcp_connection));
2004 th0 = tcp_buffer_hdr (b0);
2006 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2010 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2011 vlib_frame_t * frame, u8 is_ip4)
2015 n_left = frame->n_vectors;
2016 from = vlib_frame_vector_args (frame);
2020 tcp_connection_t *tc0;
2027 b0 = vlib_get_buffer (vm, bi0);
2029 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2031 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2032 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2034 th0 = tcp_buffer_hdr (b0);
2035 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2044 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2045 u8 is_ip4, u32 evt, u32 val)
2048 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2050 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2053 #define tcp_maybe_inc_counter(node_id, err, count) \
2055 if (next0 != tcp_next_drop (is_ip4)) \
2056 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2057 tcp6_##node_id##_node.index, is_ip4, err, \
2060 #define tcp_inc_counter(node_id, err, count) \
2061 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2062 tcp6_##node_id##_node.index, is_ip4, \
2064 #define tcp_maybe_inc_err_counter(cnts, err) \
2066 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2068 #define tcp_inc_err_counter(cnts, err, val) \
2072 #define tcp_store_err_counters(node_id, cnts) \
2075 for (i = 0; i < TCP_N_ERROR; i++) \
2077 tcp_inc_counter(node_id, i, cnts[i]); \
2082 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2083 vlib_frame_t * frame, int is_ip4)
2085 u32 thread_index = vm->thread_index, errors = 0;
2086 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2087 u32 n_left_from, *from, *first_buffer;
2088 u16 err_counters[TCP_N_ERROR] = { 0 };
2090 if (node->flags & VLIB_NODE_FLAG_TRACE)
2091 tcp_established_trace_frame (vm, node, frame, is_ip4);
2093 first_buffer = from = vlib_frame_vector_args (frame);
2094 n_left_from = frame->n_vectors;
2096 while (n_left_from > 0)
2098 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2101 tcp_connection_t *tc0;
2103 if (n_left_from > 1)
2106 pb = vlib_get_buffer (vm, from[1]);
2107 vlib_prefetch_buffer_header (pb, LOAD);
2108 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2115 b0 = vlib_get_buffer (vm, bi0);
2116 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2119 if (PREDICT_FALSE (tc0 == 0))
2121 error0 = TCP_ERROR_INVALID_CONNECTION;
2125 th0 = tcp_buffer_hdr (b0);
2127 /* TODO header prediction fast path */
2129 /* 1-4: check SEQ, RST, SYN */
2130 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2132 TCP_EVT (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2136 /* 5: check the ACK field */
2137 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2140 /* 6: check the URG bit TODO */
2142 /* 7: process the segment text */
2143 if (vnet_buffer (b0)->tcp.data_len)
2144 error0 = tcp_segment_rcv (wrk, tc0, b0);
2146 /* 8: check the FIN bit */
2147 if (PREDICT_FALSE (tcp_is_fin (th0)))
2148 tcp_rcv_fin (wrk, tc0, b0, &error0);
2151 tcp_inc_err_counter (err_counters, error0, 1);
2154 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2156 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2157 tcp_store_err_counters (established, err_counters);
2158 tcp_handle_postponed_dequeues (wrk);
2159 tcp_handle_disconnects (wrk);
2160 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2162 return frame->n_vectors;
2165 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2166 vlib_node_runtime_t * node,
2167 vlib_frame_t * from_frame)
2169 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2172 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2173 vlib_node_runtime_t * node,
2174 vlib_frame_t * from_frame)
2176 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2180 VLIB_REGISTER_NODE (tcp4_established_node) =
2182 .name = "tcp4-established",
2183 /* Takes a vector of packets. */
2184 .vector_size = sizeof (u32),
2185 .n_errors = TCP_N_ERROR,
2186 .error_strings = tcp_error_strings,
2187 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2190 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2191 foreach_tcp_state_next
2194 .format_trace = format_tcp_rx_trace_short,
2199 VLIB_REGISTER_NODE (tcp6_established_node) =
2201 .name = "tcp6-established",
2202 /* Takes a vector of packets. */
2203 .vector_size = sizeof (u32),
2204 .n_errors = TCP_N_ERROR,
2205 .error_strings = tcp_error_strings,
2206 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2209 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2210 foreach_tcp_state_next
2213 .format_trace = format_tcp_rx_trace_short,
2219 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2221 transport_connection_t *tmp = 0;
2228 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2231 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2232 && (tc->state == TCP_STATE_LISTEN
2233 || tc->c_rmt_port == hdr->src_port));
2237 handle = session_lookup_half_open_handle (&tc->connection);
2238 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2239 tc->c_proto, tc->c_is_ip4);
2243 if (tmp->lcl_port == hdr->dst_port
2244 && tmp->rmt_port == hdr->src_port)
2246 TCP_DBG ("half-open is valid!");
2254 * Lookup transport connection
2256 static tcp_connection_t *
2257 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2261 transport_connection_t *tconn;
2262 tcp_connection_t *tc;
2267 ip4 = vlib_buffer_get_current (b);
2268 tcp = ip4_next_header (ip4);
2269 tconn = session_lookup_connection_wt4 (fib_index,
2274 TRANSPORT_PROTO_TCP,
2275 thread_index, &is_filtered);
2276 tc = tcp_get_connection_from_transport (tconn);
2277 ASSERT (tcp_lookup_is_valid (tc, tcp));
2282 ip6 = vlib_buffer_get_current (b);
2283 tcp = ip6_next_header (ip6);
2284 tconn = session_lookup_connection_wt6 (fib_index,
2289 TRANSPORT_PROTO_TCP,
2290 thread_index, &is_filtered);
2291 tc = tcp_get_connection_from_transport (tconn);
2292 ASSERT (tcp_lookup_is_valid (tc, tcp));
2298 tcp_check_tx_offload (tcp_connection_t * tc, int is_ipv4)
2300 vnet_main_t *vnm = vnet_get_main ();
2301 const dpo_id_t *dpo;
2302 const load_balance_t *lb;
2303 vnet_hw_interface_t *hw_if;
2304 u32 sw_if_idx, lb_idx;
2308 ip4_address_t *dst_addr = &(tc->c_rmt_ip.ip4);
2309 lb_idx = ip4_fib_forwarding_lookup (tc->c_fib_index, dst_addr);
2313 ip6_address_t *dst_addr = &(tc->c_rmt_ip.ip6);
2314 lb_idx = ip6_fib_table_fwding_lookup (tc->c_fib_index, dst_addr);
2317 lb = load_balance_get (lb_idx);
2318 dpo = load_balance_get_bucket_i (lb, 0);
2320 sw_if_idx = dpo->dpoi_index;
2321 hw_if = vnet_get_sup_hw_interface (vnm, sw_if_idx);
2324 ((hw_if->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO) == 0) ? 0 : 1;
2329 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2330 vlib_frame_t * from_frame, int is_ip4)
2332 u32 n_left_from, *from, *first_buffer, errors = 0;
2333 u32 my_thread_index = vm->thread_index;
2334 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2336 from = first_buffer = vlib_frame_vector_args (from_frame);
2337 n_left_from = from_frame->n_vectors;
2339 while (n_left_from > 0)
2341 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2342 tcp_connection_t *tc0, *new_tc0;
2343 tcp_header_t *tcp0 = 0;
2351 b0 = vlib_get_buffer (vm, bi0);
2353 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2354 if (PREDICT_FALSE (tc0 == 0))
2356 error0 = TCP_ERROR_INVALID_CONNECTION;
2360 /* Half-open completed recently but the connection was't removed
2361 * yet by the owning thread */
2362 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2364 /* Make sure the connection actually exists */
2365 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2366 my_thread_index, is_ip4));
2367 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2371 ack0 = vnet_buffer (b0)->tcp.ack_number;
2372 seq0 = vnet_buffer (b0)->tcp.seq_number;
2373 tcp0 = tcp_buffer_hdr (b0);
2375 /* Crude check to see if the connection handle does not match
2376 * the packet. Probably connection just switched to established */
2377 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2378 || tcp0->src_port != tc0->c_rmt_port))
2380 error0 = TCP_ERROR_INVALID_CONNECTION;
2384 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2385 && !tcp_syn (tcp0)))
2387 error0 = TCP_ERROR_SEGMENT_INVALID;
2391 /* SYNs consume sequence numbers */
2392 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2395 * 1. check the ACK bit
2399 * If the ACK bit is set
2400 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2401 * the RST bit is set, if so drop the segment and return)
2402 * <SEQ=SEG.ACK><CTL=RST>
2403 * and discard the segment. Return.
2404 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2408 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2410 if (!tcp_rst (tcp0))
2411 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2412 error0 = TCP_ERROR_RCV_WND;
2416 /* Make sure ACK is valid */
2417 if (seq_gt (tc0->snd_una, ack0))
2419 error0 = TCP_ERROR_ACK_INVALID;
2425 * 2. check the RST bit
2430 /* If ACK is acceptable, signal client that peer is not
2431 * willing to accept connection and drop connection*/
2433 tcp_connection_reset (tc0);
2434 error0 = TCP_ERROR_RST_RCVD;
2439 * 3. check the security and precedence (skipped)
2443 * 4. check the SYN bit
2446 /* No SYN flag. Drop. */
2447 if (!tcp_syn (tcp0))
2449 error0 = TCP_ERROR_SEGMENT_INVALID;
2454 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2456 error0 = TCP_ERROR_OPTIONS;
2460 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2461 * current thread pool. */
2462 new_tc0 = tcp_connection_alloc_w_base (my_thread_index, tc0);
2463 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2464 new_tc0->irs = seq0;
2465 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2466 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2468 /* If this is not the owning thread, wait for syn retransmit to
2469 * expire and cleanup then */
2470 if (tcp_half_open_connection_cleanup (tc0))
2471 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2473 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2475 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2476 new_tc0->tsval_recent_age = tcp_time_now ();
2479 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2480 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2482 new_tc0->rcv_wscale = 0;
2484 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2485 << new_tc0->snd_wscale;
2486 new_tc0->snd_wl1 = seq0;
2487 new_tc0->snd_wl2 = ack0;
2489 tcp_connection_init_vars (new_tc0);
2491 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2492 if (PREDICT_TRUE (tcp_ack (tcp0)))
2494 /* Our SYN is ACKed: we have iss < ack = snd_una */
2496 /* TODO Dequeue acknowledged segments if we support Fast Open */
2497 new_tc0->snd_una = ack0;
2498 new_tc0->state = TCP_STATE_ESTABLISHED;
2500 /* Make sure las is initialized for the wnd computation */
2501 new_tc0->rcv_las = new_tc0->rcv_nxt;
2503 /* Notify app that we have connection. If session layer can't
2504 * allocate session send reset */
2505 if (session_stream_connect_notify (&new_tc0->connection, 0))
2507 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2508 tcp_connection_cleanup (new_tc0);
2509 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2513 new_tc0->tx_fifo_size =
2514 transport_tx_fifo_size (&new_tc0->connection);
2515 /* Update rtt with the syn-ack sample */
2516 tcp_estimate_initial_rtt (new_tc0);
2517 TCP_EVT (TCP_EVT_SYNACK_RCVD, new_tc0);
2518 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2520 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2523 new_tc0->state = TCP_STATE_SYN_RCVD;
2525 /* Notify app that we have connection */
2526 if (session_stream_connect_notify (&new_tc0->connection, 0))
2528 tcp_connection_cleanup (new_tc0);
2529 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2530 TCP_EVT (TCP_EVT_RST_SENT, tc0);
2531 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2535 new_tc0->tx_fifo_size =
2536 transport_tx_fifo_size (&new_tc0->connection);
2537 new_tc0->rtt_ts = 0;
2538 tcp_init_snd_vars (new_tc0);
2539 tcp_send_synack (new_tc0);
2540 error0 = TCP_ERROR_SYNS_RCVD;
2544 tcp_check_tx_offload (new_tc0, is_ip4);
2546 /* Read data, if any */
2547 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2549 clib_warning ("rcvd data in syn-sent");
2550 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2551 if (error0 == TCP_ERROR_ACK_OK)
2552 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2556 tcp_program_ack (new_tc0);
2561 tcp_inc_counter (syn_sent, error0, 1);
2562 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2564 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2565 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2566 clib_memcpy_fast (&t0->tcp_connection, tc0,
2567 sizeof (t0->tcp_connection));
2571 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2573 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2574 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2576 return from_frame->n_vectors;
2579 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2580 vlib_node_runtime_t * node,
2581 vlib_frame_t * from_frame)
2583 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2586 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2587 vlib_node_runtime_t * node,
2588 vlib_frame_t * from_frame)
2590 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2594 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2596 .name = "tcp4-syn-sent",
2597 /* Takes a vector of packets. */
2598 .vector_size = sizeof (u32),
2599 .n_errors = TCP_N_ERROR,
2600 .error_strings = tcp_error_strings,
2601 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2604 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2605 foreach_tcp_state_next
2608 .format_trace = format_tcp_rx_trace_short,
2613 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2615 .name = "tcp6-syn-sent",
2616 /* Takes a vector of packets. */
2617 .vector_size = sizeof (u32),
2618 .n_errors = TCP_N_ERROR,
2619 .error_strings = tcp_error_strings,
2620 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2623 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2624 foreach_tcp_state_next
2627 .format_trace = format_tcp_rx_trace_short,
2632 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2633 * as per RFC793 p. 64
2636 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2637 vlib_frame_t * from_frame, int is_ip4)
2639 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2640 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2641 u32 n_left_from, *from, max_dequeue;
2643 from = first_buffer = vlib_frame_vector_args (from_frame);
2644 n_left_from = from_frame->n_vectors;
2646 while (n_left_from > 0)
2648 u32 bi0, error0 = TCP_ERROR_NONE;
2649 tcp_header_t *tcp0 = 0;
2650 tcp_connection_t *tc0;
2658 b0 = vlib_get_buffer (vm, bi0);
2659 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2661 if (PREDICT_FALSE (tc0 == 0))
2663 error0 = TCP_ERROR_INVALID_CONNECTION;
2667 tcp0 = tcp_buffer_hdr (b0);
2668 is_fin0 = tcp_is_fin (tcp0);
2672 tcp_connection_t *tmp;
2673 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2675 if (tmp->state != tc0->state)
2677 if (tc0->state != TCP_STATE_CLOSED)
2678 clib_warning ("state changed");
2684 * Special treatment for CLOSED
2686 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2688 error0 = TCP_ERROR_CONNECTION_CLOSED;
2693 * For all other states (except LISTEN)
2696 /* 1-4: check SEQ, RST, SYN */
2697 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2700 /* 5: check the ACK field */
2703 case TCP_STATE_SYN_RCVD:
2705 /* Make sure the segment is exactly right */
2706 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2708 tcp_connection_reset (tc0);
2709 error0 = TCP_ERROR_SEGMENT_INVALID;
2714 * If the segment acknowledgment is not acceptable, form a
2716 * <SEQ=SEG.ACK><CTL=RST>
2719 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2721 tcp_connection_reset (tc0);
2725 /* Update rtt and rto */
2726 tcp_estimate_initial_rtt (tc0);
2728 /* Switch state to ESTABLISHED */
2729 tc0->state = TCP_STATE_ESTABLISHED;
2730 TCP_EVT (TCP_EVT_STATE_CHANGE, tc0);
2732 tcp_check_tx_offload (tc0, is_ip4);
2734 /* Initialize session variables */
2735 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2736 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2737 << tc0->rcv_opts.wscale;
2738 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2739 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2741 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2742 tcp_retransmit_timer_reset (tc0);
2743 if (session_stream_accept_notify (&tc0->connection))
2745 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2746 tcp_connection_reset (tc0);
2749 error0 = TCP_ERROR_ACK_OK;
2751 case TCP_STATE_ESTABLISHED:
2752 /* We can get packets in established state here because they
2753 * were enqueued before state change */
2754 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2758 case TCP_STATE_FIN_WAIT_1:
2759 /* In addition to the processing for the ESTABLISHED state, if
2760 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2761 * continue processing in that state. */
2762 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2765 /* Still have to send the FIN */
2766 if (tc0->flags & TCP_CONN_FINPNDG)
2768 /* TX fifo finally drained */
2769 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2770 if (max_dequeue <= tc0->burst_acked)
2772 /* If a fin was received and data was acked extend wait */
2773 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
2774 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2775 tcp_cfg.closewait_time);
2777 /* If FIN is ACKed */
2778 else if (tc0->snd_una == tc0->snd_nxt)
2780 /* Stop all retransmit timers because we have nothing more
2782 tcp_connection_timers_reset (tc0);
2784 /* We already have a FIN but didn't transition to CLOSING
2785 * because of outstanding tx data. Close the connection. */
2786 if (tc0->flags & TCP_CONN_FINRCVD)
2788 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2789 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE,
2790 tcp_cfg.cleanup_time);
2791 session_transport_closed_notify (&tc0->connection);
2795 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2796 /* Enable waitclose because we're willing to wait for peer's
2797 * FIN but not indefinitely. */
2798 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait2_time);
2800 /* Don't try to deq the FIN acked */
2801 if (tc0->burst_acked > 1)
2802 session_tx_fifo_dequeue_drop (&tc0->connection,
2803 tc0->burst_acked - 1);
2804 tc0->burst_acked = 0;
2807 case TCP_STATE_FIN_WAIT_2:
2808 /* In addition to the processing for the ESTABLISHED state, if
2809 * the retransmission queue is empty, the user's CLOSE can be
2810 * acknowledged ("ok") but do not delete the TCB. */
2811 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2813 tc0->burst_acked = 0;
2815 case TCP_STATE_CLOSE_WAIT:
2816 /* Do the same processing as for the ESTABLISHED state. */
2817 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2820 if (!(tc0->flags & TCP_CONN_FINPNDG))
2823 /* Still have outstanding tx data */
2824 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2825 if (max_dequeue > tc0->burst_acked)
2829 tcp_connection_timers_reset (tc0);
2830 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2831 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2833 case TCP_STATE_CLOSING:
2834 /* In addition to the processing for the ESTABLISHED state, if
2835 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2836 * otherwise ignore the segment. */
2837 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2840 if (tc0->snd_una != tc0->snd_nxt)
2843 tcp_connection_timers_reset (tc0);
2844 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2845 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2846 session_transport_closed_notify (&tc0->connection);
2850 case TCP_STATE_LAST_ACK:
2851 /* The only thing that [should] arrive in this state is an
2852 * acknowledgment of our FIN. If our FIN is now acknowledged,
2853 * delete the TCB, enter the CLOSED state, and return. */
2855 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2858 /* Apparently our ACK for the peer's FIN was lost */
2859 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2865 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2866 session_transport_closed_notify (&tc0->connection);
2868 /* Don't free the connection from the data path since
2869 * we can't ensure that we have no packets already enqueued
2870 * to output. Rely instead on the waitclose timer */
2871 tcp_connection_timers_reset (tc0);
2872 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
2877 case TCP_STATE_TIME_WAIT:
2878 /* The only thing that can arrive in this state is a
2879 * retransmission of the remote FIN. Acknowledge it, and restart
2880 * the 2 MSL timeout. */
2882 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2888 tcp_program_ack (tc0);
2889 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2897 /* 6: check the URG bit TODO */
2899 /* 7: process the segment text */
2902 case TCP_STATE_ESTABLISHED:
2903 case TCP_STATE_FIN_WAIT_1:
2904 case TCP_STATE_FIN_WAIT_2:
2905 if (vnet_buffer (b0)->tcp.data_len)
2906 error0 = tcp_segment_rcv (wrk, tc0, b0);
2908 case TCP_STATE_CLOSE_WAIT:
2909 case TCP_STATE_CLOSING:
2910 case TCP_STATE_LAST_ACK:
2911 case TCP_STATE_TIME_WAIT:
2912 /* This should not occur, since a FIN has been received from the
2913 * remote side. Ignore the segment text. */
2917 /* 8: check the FIN bit */
2921 TCP_EVT (TCP_EVT_FIN_RCVD, tc0);
2925 case TCP_STATE_ESTABLISHED:
2926 /* Account for the FIN and send ack */
2928 tcp_program_ack (tc0);
2929 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2930 tcp_program_disconnect (wrk, tc0);
2931 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
2933 case TCP_STATE_SYN_RCVD:
2934 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2935 * notified yet, set a cleanup timer instead of relying on
2936 * disconnect notify and the implicit close call. */
2937 tcp_connection_timers_reset (tc0);
2940 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2941 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2943 case TCP_STATE_CLOSE_WAIT:
2944 case TCP_STATE_CLOSING:
2945 case TCP_STATE_LAST_ACK:
2948 case TCP_STATE_FIN_WAIT_1:
2951 if (tc0->flags & TCP_CONN_FINPNDG)
2953 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
2954 * sending it. Since we already received a fin, do not wait
2956 tc0->flags |= TCP_CONN_FINRCVD;
2957 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2958 tcp_cfg.closewait_time);
2962 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
2963 tcp_program_ack (tc0);
2964 /* Wait for ACK for our FIN but not forever */
2965 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2966 tcp_cfg.closing_time);
2969 case TCP_STATE_FIN_WAIT_2:
2970 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2972 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2973 tcp_connection_timers_reset (tc0);
2974 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2975 tcp_program_ack (tc0);
2976 session_transport_closed_notify (&tc0->connection);
2978 case TCP_STATE_TIME_WAIT:
2979 /* Remain in the TIME-WAIT state. Restart the time-wait
2982 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2985 error0 = TCP_ERROR_FIN_RCVD;
2989 tcp_inc_counter (rcv_process, error0, 1);
2990 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2992 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2993 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2997 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2999 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3000 tcp_handle_postponed_dequeues (wrk);
3001 tcp_handle_disconnects (wrk);
3002 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3004 return from_frame->n_vectors;
3007 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
3008 vlib_node_runtime_t * node,
3009 vlib_frame_t * from_frame)
3011 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3014 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
3015 vlib_node_runtime_t * node,
3016 vlib_frame_t * from_frame)
3018 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3022 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3024 .name = "tcp4-rcv-process",
3025 /* Takes a vector of packets. */
3026 .vector_size = sizeof (u32),
3027 .n_errors = TCP_N_ERROR,
3028 .error_strings = tcp_error_strings,
3029 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3032 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3033 foreach_tcp_state_next
3036 .format_trace = format_tcp_rx_trace_short,
3041 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3043 .name = "tcp6-rcv-process",
3044 /* Takes a vector of packets. */
3045 .vector_size = sizeof (u32),
3046 .n_errors = TCP_N_ERROR,
3047 .error_strings = tcp_error_strings,
3048 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3051 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3052 foreach_tcp_state_next
3055 .format_trace = format_tcp_rx_trace_short,
3060 * LISTEN state processing as per RFC 793 p. 65
3063 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3064 vlib_frame_t * from_frame, int is_ip4)
3066 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3067 u32 my_thread_index = vm->thread_index;
3069 from = first_buffer = vlib_frame_vector_args (from_frame);
3070 n_left_from = from_frame->n_vectors;
3072 while (n_left_from > 0)
3077 tcp_header_t *th0 = 0;
3078 tcp_connection_t *lc0;
3081 tcp_connection_t *child0;
3082 u32 error0 = TCP_ERROR_NONE;
3088 b0 = vlib_get_buffer (vm, bi0);
3089 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3093 ip40 = vlib_buffer_get_current (b0);
3094 th0 = ip4_next_header (ip40);
3098 ip60 = vlib_buffer_get_current (b0);
3099 th0 = ip6_next_header (ip60);
3102 /* Create child session. For syn-flood protection use filter */
3104 /* 1. first check for an RST: handled in dispatch */
3105 /* if (tcp_rst (th0))
3109 /* 2. second check for an ACK: handled in dispatch */
3110 /* if (tcp_ack (th0))
3112 tcp_send_reset (b0, is_ip4);
3117 /* 3. check for a SYN (did that already) */
3119 /* Make sure connection wasn't just created */
3120 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3122 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3124 error0 = TCP_ERROR_CREATE_EXISTS;
3128 /* Create child session and send SYN-ACK */
3129 child0 = tcp_connection_alloc (my_thread_index);
3130 child0->c_lcl_port = th0->dst_port;
3131 child0->c_rmt_port = th0->src_port;
3132 child0->c_is_ip4 = is_ip4;
3133 child0->state = TCP_STATE_SYN_RCVD;
3134 child0->c_fib_index = lc0->c_fib_index;
3135 child0->cc_algo = lc0->cc_algo;
3139 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3140 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3144 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3145 sizeof (ip6_address_t));
3146 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3147 sizeof (ip6_address_t));
3150 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3152 error0 = TCP_ERROR_OPTIONS;
3153 tcp_connection_free (child0);
3157 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3158 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3159 child0->rcv_las = child0->rcv_nxt;
3160 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3162 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3163 * segments are used to initialize PAWS. */
3164 if (tcp_opts_tstamp (&child0->rcv_opts))
3166 child0->tsval_recent = child0->rcv_opts.tsval;
3167 child0->tsval_recent_age = tcp_time_now ();
3170 if (tcp_opts_wscale (&child0->rcv_opts))
3171 child0->snd_wscale = child0->rcv_opts.wscale;
3173 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3174 << child0->snd_wscale;
3175 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3176 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3178 tcp_connection_init_vars (child0);
3179 child0->rto = TCP_RTO_MIN;
3181 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3182 lc0->c_thread_index, 0 /* notify */ ))
3184 tcp_connection_cleanup (child0);
3185 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3189 TCP_EVT (TCP_EVT_SYN_RCVD, child0, 1);
3190 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3191 tcp_send_synack (child0);
3195 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3197 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3198 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3199 clib_memcpy_fast (&t0->tcp_connection, lc0,
3200 sizeof (t0->tcp_connection));
3203 n_syns += (error0 == TCP_ERROR_NONE);
3206 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3207 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3209 return from_frame->n_vectors;
3212 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3213 vlib_frame_t * from_frame)
3215 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3218 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3219 vlib_frame_t * from_frame)
3221 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3225 VLIB_REGISTER_NODE (tcp4_listen_node) =
3227 .name = "tcp4-listen",
3228 /* Takes a vector of packets. */
3229 .vector_size = sizeof (u32),
3230 .n_errors = TCP_N_ERROR,
3231 .error_strings = tcp_error_strings,
3232 .n_next_nodes = TCP_LISTEN_N_NEXT,
3235 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3236 foreach_tcp_state_next
3239 .format_trace = format_tcp_rx_trace_short,
3244 VLIB_REGISTER_NODE (tcp6_listen_node) =
3246 .name = "tcp6-listen",
3247 /* Takes a vector of packets. */
3248 .vector_size = sizeof (u32),
3249 .n_errors = TCP_N_ERROR,
3250 .error_strings = tcp_error_strings,
3251 .n_next_nodes = TCP_LISTEN_N_NEXT,
3254 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3255 foreach_tcp_state_next
3258 .format_trace = format_tcp_rx_trace_short,
3262 typedef enum _tcp_input_next
3264 TCP_INPUT_NEXT_DROP,
3265 TCP_INPUT_NEXT_LISTEN,
3266 TCP_INPUT_NEXT_RCV_PROCESS,
3267 TCP_INPUT_NEXT_SYN_SENT,
3268 TCP_INPUT_NEXT_ESTABLISHED,
3269 TCP_INPUT_NEXT_RESET,
3270 TCP_INPUT_NEXT_PUNT,
3274 #define foreach_tcp4_input_next \
3275 _ (DROP, "ip4-drop") \
3276 _ (LISTEN, "tcp4-listen") \
3277 _ (RCV_PROCESS, "tcp4-rcv-process") \
3278 _ (SYN_SENT, "tcp4-syn-sent") \
3279 _ (ESTABLISHED, "tcp4-established") \
3280 _ (RESET, "tcp4-reset") \
3281 _ (PUNT, "ip4-punt")
3283 #define foreach_tcp6_input_next \
3284 _ (DROP, "ip6-drop") \
3285 _ (LISTEN, "tcp6-listen") \
3286 _ (RCV_PROCESS, "tcp6-rcv-process") \
3287 _ (SYN_SENT, "tcp6-syn-sent") \
3288 _ (ESTABLISHED, "tcp6-established") \
3289 _ (RESET, "tcp6-reset") \
3290 _ (PUNT, "ip6-punt")
3292 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3295 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3296 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3298 tcp_connection_t *tc;
3303 for (i = 0; i < n_bufs; i++)
3305 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3307 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3308 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3310 tcp = vlib_buffer_get_current (bs[i]);
3311 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3317 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3319 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3321 *next = TCP_INPUT_NEXT_DROP;
3323 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3325 *next = TCP_INPUT_NEXT_PUNT;
3326 *error = TCP_ERROR_PUNT;
3330 *next = TCP_INPUT_NEXT_RESET;
3331 *error = TCP_ERROR_NO_LISTENER;
3335 always_inline tcp_connection_t *
3336 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3337 u8 is_ip4, u8 is_nolookup)
3339 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3340 int n_advance_bytes, n_data_bytes;
3341 transport_connection_t *tc;
3347 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3348 int ip_hdr_bytes = ip4_header_bytes (ip4);
3349 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3351 *error = TCP_ERROR_LENGTH;
3354 tcp = ip4_next_header (ip4);
3355 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3356 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3357 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3359 /* Length check. Checksum computed by ipx_local no need to compute again */
3360 if (PREDICT_FALSE (n_data_bytes < 0))
3362 *error = TCP_ERROR_LENGTH;
3367 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3368 &ip4->src_address, tcp->dst_port,
3370 TRANSPORT_PROTO_TCP, thread_index,
3375 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3376 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3378 *error = TCP_ERROR_LENGTH;
3381 tcp = ip6_next_header (ip6);
3382 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3383 n_advance_bytes = tcp_header_bytes (tcp);
3384 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3386 n_advance_bytes += sizeof (ip6[0]);
3388 if (PREDICT_FALSE (n_data_bytes < 0))
3390 *error = TCP_ERROR_LENGTH;
3397 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3399 ip4_main_t *im = &ip4_main;
3400 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3401 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3404 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3406 tcp->dst_port, tcp->src_port,
3407 TRANSPORT_PROTO_TCP,
3408 thread_index, &result);
3414 (transport_connection_t *) tcp_connection_get (vnet_buffer (b)->
3415 tcp.connection_index,
3418 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3419 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3420 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3421 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3422 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3424 vnet_buffer (b)->tcp.flags = 0;
3426 *error = result ? TCP_ERROR_NONE + result : *error;
3428 return tcp_get_connection_from_transport (tc);
3432 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3433 vlib_buffer_t * b, u16 * next, u32 * error)
3438 tcp = tcp_buffer_hdr (b);
3439 flags = tcp->flags & filter_flags;
3440 *next = tm->dispatch_table[tc->state][flags].next;
3441 *error = tm->dispatch_table[tc->state][flags].error;
3444 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3445 || *next == TCP_INPUT_NEXT_RESET))
3447 /* Overload tcp flags to store state */
3448 tcp_state_t state = tc->state;
3449 vnet_buffer (b)->tcp.flags = tc->state;
3451 if (*error == TCP_ERROR_DISPATCH)
3452 clib_warning ("tcp conn %u disp error state %U flags %U",
3453 tc->c_c_index, format_tcp_state, state,
3454 format_tcp_flags, (int) flags);
3459 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3460 vlib_frame_t * frame, int is_ip4, u8 is_nolookup)
3462 u32 n_left_from, *from, thread_index = vm->thread_index;
3463 tcp_main_t *tm = vnet_get_tcp_main ();
3464 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3465 u16 nexts[VLIB_FRAME_SIZE], *next;
3467 tcp_set_time_now (tcp_get_worker (thread_index));
3469 from = vlib_frame_vector_args (frame);
3470 n_left_from = frame->n_vectors;
3471 vlib_get_buffers (vm, from, bufs, n_left_from);
3476 while (n_left_from >= 4)
3478 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3479 tcp_connection_t *tc0, *tc1;
3482 vlib_prefetch_buffer_header (b[2], STORE);
3483 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3485 vlib_prefetch_buffer_header (b[3], STORE);
3486 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3489 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3491 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3493 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4,
3496 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3498 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3499 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3501 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3502 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3504 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3505 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3509 if (PREDICT_TRUE (tc0 != 0))
3511 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3512 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3513 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3516 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3518 if (PREDICT_TRUE (tc1 != 0))
3520 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3521 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3522 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3525 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3532 while (n_left_from > 0)
3534 tcp_connection_t *tc0;
3535 u32 error0 = TCP_ERROR_NO_LISTENER;
3537 if (n_left_from > 1)
3539 vlib_prefetch_buffer_header (b[1], STORE);
3540 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3543 next[0] = TCP_INPUT_NEXT_DROP;
3544 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3546 if (PREDICT_TRUE (tc0 != 0))
3548 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3549 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3550 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3553 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3560 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3561 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3563 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3564 return frame->n_vectors;
3567 VLIB_NODE_FN (tcp4_input_nolookup_node) (vlib_main_t * vm,
3568 vlib_node_runtime_t * node,
3569 vlib_frame_t * from_frame)
3571 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3572 1 /* is_nolookup */ );
3575 VLIB_NODE_FN (tcp6_input_nolookup_node) (vlib_main_t * vm,
3576 vlib_node_runtime_t * node,
3577 vlib_frame_t * from_frame)
3579 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3580 1 /* is_nolookup */ );
3584 VLIB_REGISTER_NODE (tcp4_input_nolookup_node) =
3586 .name = "tcp4-input-nolookup",
3587 /* Takes a vector of packets. */
3588 .vector_size = sizeof (u32),
3589 .n_errors = TCP_N_ERROR,
3590 .error_strings = tcp_error_strings,
3591 .n_next_nodes = TCP_INPUT_N_NEXT,
3594 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3595 foreach_tcp4_input_next
3598 .format_buffer = format_tcp_header,
3599 .format_trace = format_tcp_rx_trace,
3604 VLIB_REGISTER_NODE (tcp6_input_nolookup_node) =
3606 .name = "tcp6-input-nolookup",
3607 /* Takes a vector of packets. */
3608 .vector_size = sizeof (u32),
3609 .n_errors = TCP_N_ERROR,
3610 .error_strings = tcp_error_strings,
3611 .n_next_nodes = TCP_INPUT_N_NEXT,
3614 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3615 foreach_tcp6_input_next
3618 .format_buffer = format_tcp_header,
3619 .format_trace = format_tcp_rx_trace,
3623 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3624 vlib_frame_t * from_frame)
3626 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3627 0 /* is_nolookup */ );
3630 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3631 vlib_frame_t * from_frame)
3633 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3634 0 /* is_nolookup */ );
3638 VLIB_REGISTER_NODE (tcp4_input_node) =
3640 .name = "tcp4-input",
3641 /* Takes a vector of packets. */
3642 .vector_size = sizeof (u32),
3643 .n_errors = TCP_N_ERROR,
3644 .error_strings = tcp_error_strings,
3645 .n_next_nodes = TCP_INPUT_N_NEXT,
3648 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3649 foreach_tcp4_input_next
3652 .format_buffer = format_tcp_header,
3653 .format_trace = format_tcp_rx_trace,
3658 VLIB_REGISTER_NODE (tcp6_input_node) =
3660 .name = "tcp6-input",
3661 /* Takes a vector of packets. */
3662 .vector_size = sizeof (u32),
3663 .n_errors = TCP_N_ERROR,
3664 .error_strings = tcp_error_strings,
3665 .n_next_nodes = TCP_INPUT_N_NEXT,
3668 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3669 foreach_tcp6_input_next
3672 .format_buffer = format_tcp_header,
3673 .format_trace = format_tcp_rx_trace,
3677 #ifndef CLIB_MARCH_VARIANT
3679 tcp_dispatch_table_init (tcp_main_t * tm)
3682 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3683 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3685 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3686 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3689 #define _(t,f,n,e) \
3691 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3692 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3695 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3696 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3697 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3698 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3699 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3700 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3701 TCP_ERROR_ACK_INVALID);
3702 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3703 TCP_ERROR_SEGMENT_INVALID);
3704 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3705 TCP_ERROR_SEGMENT_INVALID);
3706 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3707 TCP_ERROR_INVALID_CONNECTION);
3708 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3709 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3710 TCP_ERROR_SEGMENT_INVALID);
3711 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3712 TCP_ERROR_SEGMENT_INVALID);
3713 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3715 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3716 TCP_ERROR_SEGMENT_INVALID);
3717 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3718 TCP_ERROR_SEGMENT_INVALID);
3719 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3720 TCP_ERROR_SEGMENT_INVALID);
3721 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3722 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3723 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3724 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3725 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3726 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3728 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3729 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3731 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3733 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3734 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3735 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3736 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3738 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3740 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3741 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3742 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3744 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3745 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3746 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3747 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3748 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3749 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3750 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3751 /* SYN-ACK for a SYN */
3752 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3754 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3755 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3756 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3758 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3759 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3761 /* ACK for for established connection -> tcp-established. */
3762 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3763 /* FIN for for established connection -> tcp-established. */
3764 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3765 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3767 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3769 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3770 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3771 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3773 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3774 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3775 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3776 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3777 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3778 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3779 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3780 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3782 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3783 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3785 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3787 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3788 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3789 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3790 /* ACK or FIN-ACK to our FIN */
3791 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3792 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3794 /* FIN in reply to our FIN from the other side */
3795 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3796 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3797 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3799 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3800 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3801 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3802 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3803 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3804 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3805 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3807 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3808 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3809 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3810 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3812 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3814 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3815 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3816 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3817 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3819 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3820 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3821 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3822 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3824 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3826 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3827 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3828 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3829 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3831 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3832 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3834 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3836 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3837 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3838 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3840 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3841 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3842 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3843 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3844 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3845 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3846 /* FIN confirming that the peer (app) has closed */
3847 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3848 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3849 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3851 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3852 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3854 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3855 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3857 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3858 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3860 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3861 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3862 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3863 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3865 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3867 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3868 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3869 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3871 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3872 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3873 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3874 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3875 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3876 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3877 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3878 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3880 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3881 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3883 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3885 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3886 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3887 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3888 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3889 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3891 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3892 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3894 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3895 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3896 * incoming segment not containing a RST causes a RST to be sent in
3898 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3899 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3900 TCP_ERROR_CONNECTION_CLOSED);
3901 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3902 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3903 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3908 static clib_error_t *
3909 tcp_input_init (vlib_main_t * vm)
3911 clib_error_t *error = 0;
3912 tcp_main_t *tm = vnet_get_tcp_main ();
3914 if ((error = vlib_call_init_function (vm, tcp_init)))
3917 /* Initialize dispatch table. */
3918 tcp_dispatch_table_init (tm);
3923 VLIB_INIT_FUNCTION (tcp_input_init);
3925 #endif /* CLIB_MARCH_VARIANT */
3928 * fd.io coding-style-patch-verification: ON
3931 * eval: (c-set-style "gnu")