2 * Copyright (c) 2016-2019 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #include <vppinfra/sparse_vec.h>
17 #include <vnet/fib/ip4_fib.h>
18 #include <vnet/fib/ip6_fib.h>
19 #include <vnet/tcp/tcp_packet.h>
20 #include <vnet/tcp/tcp.h>
21 #include <vnet/session/session.h>
24 static char *tcp_error_strings[] = {
25 #define tcp_error(n,s) s,
26 #include <vnet/tcp/tcp_error.def>
30 /* All TCP nodes have the same outgoing arcs */
31 #define foreach_tcp_state_next \
32 _ (DROP4, "ip4-drop") \
33 _ (DROP6, "ip6-drop") \
34 _ (TCP4_OUTPUT, "tcp4-output") \
35 _ (TCP6_OUTPUT, "tcp6-output")
37 typedef enum _tcp_established_next
39 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
40 foreach_tcp_state_next
42 TCP_ESTABLISHED_N_NEXT,
43 } tcp_established_next_t;
45 typedef enum _tcp_rcv_process_next
47 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
48 foreach_tcp_state_next
50 TCP_RCV_PROCESS_N_NEXT,
51 } tcp_rcv_process_next_t;
53 typedef enum _tcp_syn_sent_next
55 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
56 foreach_tcp_state_next
59 } tcp_syn_sent_next_t;
61 typedef enum _tcp_listen_next
63 #define _(s,n) TCP_LISTEN_NEXT_##s,
64 foreach_tcp_state_next
69 /* Generic, state independent indices */
70 typedef enum _tcp_state_next
72 #define _(s,n) TCP_NEXT_##s,
73 foreach_tcp_state_next
78 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
79 : TCP_NEXT_TCP6_OUTPUT)
81 #define tcp_next_drop(is_ip4) (is_ip4 ? TCP_NEXT_DROP4 \
85 * Validate segment sequence number. As per RFC793:
87 * Segment Receive Test
89 * ------- ------- -------------------------------------------
90 * 0 0 SEG.SEQ = RCV.NXT
91 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
93 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
94 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
96 * This ultimately consists in checking if segment falls within the window.
97 * The one important difference compared to RFC793 is that we use rcv_las,
98 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
99 * peer's reference when computing our receive window.
102 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
103 * however, is too strict when we have retransmits. Instead we just check that
104 * the seq is not beyond the right edge and that the end of the segment is not
105 * less than the left edge.
107 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
108 * use rcv_nxt in the right edge window test instead of rcv_las.
112 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
114 return (seq_geq (end_seq, tc->rcv_las)
115 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
119 * Parse TCP header options.
121 * @param th TCP header
122 * @param to TCP options data structure to be populated
123 * @param is_syn set if packet is syn
124 * @return -1 if parsing failed
127 tcp_options_parse (tcp_header_t * th, tcp_options_t * to, u8 is_syn)
130 u8 opt_len, opts_len, kind;
134 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
135 data = (const u8 *) (th + 1);
137 /* Zero out all flags but those set in SYN */
138 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
139 | TCP_OPTS_FLAG_TSTAMP | TCP_OPTION_MSS);
141 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
145 /* Get options length */
146 if (kind == TCP_OPTION_EOL)
148 else if (kind == TCP_OPTION_NOOP)
160 /* weird option length */
161 if (opt_len < 2 || opt_len > opts_len)
171 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
173 to->flags |= TCP_OPTS_FLAG_MSS;
174 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
177 case TCP_OPTION_WINDOW_SCALE:
180 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
182 to->flags |= TCP_OPTS_FLAG_WSCALE;
183 to->wscale = data[2];
184 if (to->wscale > TCP_MAX_WND_SCALE)
185 to->wscale = TCP_MAX_WND_SCALE;
188 case TCP_OPTION_TIMESTAMP:
190 to->flags |= TCP_OPTS_FLAG_TSTAMP;
191 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
192 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
194 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
195 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
198 case TCP_OPTION_SACK_PERMITTED:
201 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
202 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
204 case TCP_OPTION_SACK_BLOCK:
205 /* If SACK permitted was not advertised or a SYN, break */
206 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
209 /* If too short or not correctly formatted, break */
210 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
213 to->flags |= TCP_OPTS_FLAG_SACK;
214 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
215 vec_reset_length (to->sacks);
216 for (j = 0; j < to->n_sack_blocks; j++)
218 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
219 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
220 vec_add1 (to->sacks, b);
224 /* Nothing to see here */
232 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
233 * timestamp to echo and it's less than tsval_recent, drop segment
234 * but still send an ACK in order to retain TCP's mechanism for detecting
235 * and recovering from half-open connections
237 * Or at least that's what the theory says. It seems that this might not work
238 * very well with packet reordering and fast retransmit. XXX
241 tcp_segment_check_paws (tcp_connection_t * tc)
243 return tcp_opts_tstamp (&tc->rcv_opts)
244 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
248 * Update tsval recent
251 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
254 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
255 * of an incoming segment:
256 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
257 * then the TSval from the segment is copied to TS.Recent;
258 * otherwise, the TSval is ignored.
260 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
261 && seq_leq (tc->rcv_las, seq_end))
263 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
264 tc->tsval_recent = tc->rcv_opts.tsval;
265 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
270 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
272 * It first verifies if segment has a wrapped sequence number (PAWS) and then
273 * does the processing associated to the first four steps (ignoring security
274 * and precedence): sequence number, rst bit and syn bit checks.
276 * @return 0 if segments passes validation.
279 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
280 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
282 /* We could get a burst of RSTs interleaved with acks */
283 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
285 tcp_send_reset (tc0);
286 *error0 = TCP_ERROR_CONNECTION_CLOSED;
290 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
292 *error0 = TCP_ERROR_SEGMENT_INVALID;
296 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
298 *error0 = TCP_ERROR_OPTIONS;
302 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
304 *error0 = TCP_ERROR_PAWS;
305 TCP_EVT (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
306 vnet_buffer (b0)->tcp.seq_end);
308 /* If it just so happens that a segment updates tsval_recent for a
309 * segment over 24 days old, invalidate tsval_recent. */
310 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
311 tcp_time_now_w_thread (tc0->c_thread_index)))
313 tc0->tsval_recent = tc0->rcv_opts.tsval;
314 clib_warning ("paws failed: 24-day old segment");
316 /* Drop after ack if not rst. Resets can fail paws check as per
317 * RFC 7323 sec. 5.2: When an <RST> segment is received, it MUST NOT
318 * be subjected to the PAWS check by verifying an acceptable value in
320 else if (!tcp_rst (th0))
322 tcp_program_ack (tc0);
323 TCP_EVT (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
328 /* 1st: check sequence number */
329 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
330 vnet_buffer (b0)->tcp.seq_end))
332 /* SYN/SYN-ACK retransmit */
334 && vnet_buffer (b0)->tcp.seq_number == tc0->rcv_nxt - 1)
336 tcp_options_parse (th0, &tc0->rcv_opts, 1);
337 if (tc0->state == TCP_STATE_SYN_RCVD)
339 tcp_send_synack (tc0);
340 TCP_EVT (TCP_EVT_SYN_RCVD, tc0, 0);
341 *error0 = TCP_ERROR_SYNS_RCVD;
345 tcp_program_ack (tc0);
346 TCP_EVT (TCP_EVT_SYNACK_RCVD, tc0);
347 *error0 = TCP_ERROR_SYN_ACKS_RCVD;
352 /* If our window is 0 and the packet is in sequence, let it pass
353 * through for ack processing. It should be dropped later. */
354 if (tc0->rcv_wnd < tc0->snd_mss
355 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
358 /* If we entered recovery and peer did so as well, there's a chance that
359 * dup acks won't be acceptable on either end because seq_end may be less
360 * than rcv_las. This can happen if acks are lost in both directions. */
361 if (tcp_in_recovery (tc0)
362 && seq_geq (vnet_buffer (b0)->tcp.seq_number,
363 tc0->rcv_las - tc0->rcv_wnd)
364 && seq_leq (vnet_buffer (b0)->tcp.seq_end,
365 tc0->rcv_nxt + tc0->rcv_wnd))
368 *error0 = TCP_ERROR_RCV_WND;
370 /* If we advertised a zero rcv_wnd and the segment is in the past or the
371 * next one that we expect, it is probably a window probe */
372 if ((tc0->flags & TCP_CONN_ZERO_RWND_SENT)
373 && seq_lt (vnet_buffer (b0)->tcp.seq_end,
374 tc0->rcv_las + tc0->rcv_opts.mss))
375 *error0 = TCP_ERROR_ZERO_RWND;
377 tc0->errors.below_data_wnd += seq_lt (vnet_buffer (b0)->tcp.seq_end,
380 /* If not RST, send dup ack */
383 tcp_program_dupack (tc0);
384 TCP_EVT (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
392 /* 2nd: check the RST bit */
393 if (PREDICT_FALSE (tcp_rst (th0)))
395 tcp_connection_reset (tc0);
396 *error0 = TCP_ERROR_RST_RCVD;
400 /* 3rd: check security and precedence (skip) */
402 /* 4th: check the SYN bit (in window) */
403 if (PREDICT_FALSE (tcp_syn (th0)))
405 /* As per RFC5961 send challenge ack instead of reset */
406 tcp_program_ack (tc0);
407 *error0 = TCP_ERROR_SPURIOUS_SYN;
411 /* If segment in window, save timestamp */
412 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
413 vnet_buffer (b0)->tcp.seq_end);
421 tcp_rcv_ack_no_cc (tcp_connection_t * tc, vlib_buffer_t * b, u32 * error)
423 /* SND.UNA =< SEG.ACK =< SND.NXT */
424 if (!(seq_leq (tc->snd_una, vnet_buffer (b)->tcp.ack_number)
425 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
427 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
428 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
430 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
433 *error = TCP_ERROR_ACK_INVALID;
438 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
439 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
440 *error = TCP_ERROR_ACK_OK;
445 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
447 * Note that although the original article, srtt and rttvar are scaled
448 * to minimize round-off errors, here we don't. Instead, we rely on
449 * better precision time measurements.
451 * TODO support us rtt resolution
454 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
460 err = mrtt - tc->srtt;
462 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
463 * The increase should be bound */
464 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
465 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
466 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
470 /* First measurement. */
472 tc->rttvar = mrtt >> 1;
476 #ifndef CLIB_MARCH_VARIANT
478 tcp_update_rto (tcp_connection_t * tc)
480 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
481 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
483 #endif /* CLIB_MARCH_VARIANT */
486 * Update RTT estimate and RTO timer
488 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
489 * timing. Middle boxes are known to fiddle with TCP options so we
490 * should give higher priority to ACK timing.
492 * This should be called only if previously sent bytes have been acked.
494 * return 1 if valid rtt 0 otherwise
497 tcp_update_rtt (tcp_connection_t * tc, tcp_rate_sample_t * rs, u32 ack)
501 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
502 * RTT because they're ambiguous. */
503 if (tcp_in_cong_recovery (tc))
505 /* Accept rtt estimates for samples that have not been retransmitted */
506 if ((tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
507 && !(rs->flags & TCP_BTS_IS_RXT))
509 mrtt = rs->rtt_time * THZ;
515 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
517 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
518 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
519 mrtt = clib_max ((u32) (sample * THZ), 1);
520 /* Allow measuring of a new RTT */
523 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
524 * snd_una, i.e., the left side of the send window:
525 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
526 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
528 u32 now = tcp_tstamp (tc);
529 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
534 /* Ignore dubious measurements */
535 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
538 tcp_estimate_rtt (tc, mrtt);
542 /* If we got here something must've been ACKed so make sure boff is 0,
543 * even if mrtt is not valid since we update the rto lower */
551 tcp_estimate_initial_rtt (tcp_connection_t * tc)
553 u8 thread_index = vlib_num_workers ()? 1 : 0;
558 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
559 tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001);
560 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
565 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
566 mrtt = clib_max (mrtt, 1);
567 /* Due to retransmits we don't know the initial mrtt */
568 if (tc->rto_boff && mrtt > 1 * THZ)
570 tc->mrtt_us = (f64) mrtt *TCP_TICK;
573 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
574 tcp_estimate_rtt (tc, mrtt);
579 tcp_recovery_no_snd_space (tcp_connection_t * tc)
581 return (tcp_in_fastrecovery (tc)
582 && tcp_fastrecovery_prr_snd_space (tc) < tc->snd_mss)
583 || (tcp_in_recovery (tc)
584 && tcp_available_output_snd_space (tc) < tc->snd_mss);
588 * Dequeue bytes for connections that have received acks in last burst
591 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
593 u32 thread_index = wrk->vm->thread_index;
594 u32 *pending_deq_acked;
595 tcp_connection_t *tc;
598 if (!vec_len (wrk->pending_deq_acked))
601 pending_deq_acked = wrk->pending_deq_acked;
602 for (i = 0; i < vec_len (pending_deq_acked); i++)
604 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
605 tc->flags &= ~TCP_CONN_DEQ_PENDING;
609 /* Dequeue the newly ACKed bytes */
610 session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
612 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
614 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
616 if (seq_leq (tc->psh_seq, tc->snd_una))
617 tc->flags &= ~TCP_CONN_PSH_PENDING;
620 /* If everything has been acked, stop retransmit timer
621 * otherwise update. */
622 tcp_retransmit_timer_update (tc);
624 /* Update pacer based on our new cwnd estimate */
625 tcp_connection_tx_pacer_update (tc);
628 /* Reset the pacer if we've been idle, i.e., no data sent or if
629 * we're in recovery and snd space constrained */
630 if (tc->data_segs_out == tc->prev_dsegs_out
631 || tcp_recovery_no_snd_space (tc))
632 transport_connection_tx_pacer_reset_bucket (&tc->connection,
635 tc->prev_dsegs_out = tc->data_segs_out;
637 _vec_len (wrk->pending_deq_acked) = 0;
641 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
643 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
645 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
646 tc->flags |= TCP_CONN_DEQ_PENDING;
648 tc->burst_acked += tc->bytes_acked;
651 #ifndef CLIB_MARCH_VARIANT
653 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
655 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
656 return hole - sb->holes;
660 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
662 return hole->end - hole->start;
665 sack_scoreboard_hole_t *
666 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
668 if (index != TCP_INVALID_SACK_HOLE_INDEX)
669 return pool_elt_at_index (sb->holes, index);
673 sack_scoreboard_hole_t *
674 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
676 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
677 return pool_elt_at_index (sb->holes, hole->next);
681 sack_scoreboard_hole_t *
682 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
684 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
685 return pool_elt_at_index (sb->holes, hole->prev);
689 sack_scoreboard_hole_t *
690 scoreboard_first_hole (sack_scoreboard_t * sb)
692 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
693 return pool_elt_at_index (sb->holes, sb->head);
697 sack_scoreboard_hole_t *
698 scoreboard_last_hole (sack_scoreboard_t * sb)
700 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
701 return pool_elt_at_index (sb->holes, sb->tail);
706 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
708 sack_scoreboard_hole_t *next, *prev;
710 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
712 next = pool_elt_at_index (sb->holes, hole->next);
713 next->prev = hole->prev;
717 sb->tail = hole->prev;
720 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
722 prev = pool_elt_at_index (sb->holes, hole->prev);
723 prev->next = hole->next;
727 sb->head = hole->next;
730 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
731 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
733 /* Poison the entry */
735 clib_memset (hole, 0xfe, sizeof (*hole));
737 pool_put (sb->holes, hole);
740 static sack_scoreboard_hole_t *
741 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
744 sack_scoreboard_hole_t *hole, *next, *prev;
747 pool_get (sb->holes, hole);
748 clib_memset (hole, 0, sizeof (*hole));
752 hole_index = scoreboard_hole_index (sb, hole);
754 prev = scoreboard_get_hole (sb, prev_index);
757 hole->prev = prev_index;
758 hole->next = prev->next;
760 if ((next = scoreboard_next_hole (sb, hole)))
761 next->prev = hole_index;
763 sb->tail = hole_index;
765 prev->next = hole_index;
769 sb->head = hole_index;
770 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
771 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
778 scoreboard_update_sacked_rxt (sack_scoreboard_t * sb, u32 start, u32 end,
781 if (!has_rxt || seq_geq (start, sb->high_rxt))
785 seq_lt (end, sb->high_rxt) ? (end - start) : (sb->high_rxt - start);
789 scoreboard_update_bytes (sack_scoreboard_t * sb, u32 ack, u32 snd_mss)
791 sack_scoreboard_hole_t *left, *right;
792 u32 sacked = 0, blks = 0, old_sacked;
794 old_sacked = sb->sacked_bytes;
796 sb->last_lost_bytes = 0;
798 sb->sacked_bytes = 0;
800 right = scoreboard_last_hole (sb);
803 sb->sacked_bytes = sb->high_sacked - ack;
807 if (seq_gt (sb->high_sacked, right->end))
809 sacked = sb->high_sacked - right->end;
813 while (sacked < (TCP_DUPACK_THRESHOLD - 1) * snd_mss
814 && blks < TCP_DUPACK_THRESHOLD)
817 sb->lost_bytes += scoreboard_hole_bytes (right);
819 left = scoreboard_prev_hole (sb, right);
822 ASSERT (right->start == ack || sb->is_reneging);
823 sacked += right->start - ack;
828 sacked += right->start - left->end;
833 /* right is first lost */
836 sb->lost_bytes += scoreboard_hole_bytes (right);
837 sb->last_lost_bytes += right->is_lost ? 0 : (right->end - right->start);
839 left = scoreboard_prev_hole (sb, right);
842 ASSERT (right->start == ack || sb->is_reneging);
843 sacked += right->start - ack;
846 sacked += right->start - left->end;
850 sb->sacked_bytes = sacked;
851 sb->last_sacked_bytes = sacked - (old_sacked - sb->last_bytes_delivered);
855 * Figure out the next hole to retransmit
857 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
859 sack_scoreboard_hole_t *
860 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
861 sack_scoreboard_hole_t * start,
862 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
864 sack_scoreboard_hole_t *hole = 0;
866 hole = start ? start : scoreboard_first_hole (sb);
867 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
868 hole = scoreboard_next_hole (sb, hole);
870 /* Nothing, return */
873 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
877 /* Rule (1): if higher than rxt, less than high_sacked and lost */
878 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
880 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
884 /* Rule (2): available unsent data */
887 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
890 /* Rule (3): if hole not lost */
891 else if (seq_lt (hole->start, sb->high_sacked))
894 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
896 /* Rule (4): if hole beyond high_sacked */
899 ASSERT (seq_geq (hole->start, sb->high_sacked));
902 /* HighRxt MUST NOT be updated */
907 if (hole && seq_lt (sb->high_rxt, hole->start))
908 sb->high_rxt = hole->start;
914 scoreboard_init_rxt (sack_scoreboard_t * sb, u32 snd_una)
916 sack_scoreboard_hole_t *hole;
917 hole = scoreboard_first_hole (sb);
920 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
921 sb->cur_rxt_hole = sb->head;
923 sb->high_rxt = snd_una;
924 sb->rescue_rxt = snd_una - 1;
928 scoreboard_init (sack_scoreboard_t * sb)
930 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
931 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
932 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
936 scoreboard_clear (sack_scoreboard_t * sb)
938 sack_scoreboard_hole_t *hole;
939 while ((hole = scoreboard_first_hole (sb)))
941 scoreboard_remove_hole (sb, hole);
943 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
944 ASSERT (pool_elts (sb->holes) == 0);
945 sb->sacked_bytes = 0;
946 sb->last_sacked_bytes = 0;
947 sb->last_bytes_delivered = 0;
951 sb->last_lost_bytes = 0;
952 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
957 scoreboard_clear_reneging (sack_scoreboard_t * sb, u32 start, u32 end)
959 sack_scoreboard_hole_t *last_hole;
961 clib_warning ("sack reneging");
963 scoreboard_clear (sb);
964 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
966 last_hole->is_lost = 1;
967 sb->tail = scoreboard_hole_index (sb, last_hole);
968 sb->high_sacked = start;
969 scoreboard_init_rxt (sb, start);
972 #endif /* CLIB_MARCH_VARIANT */
975 * Test that scoreboard is sane after recovery
977 * Returns 1 if scoreboard is empty or if first hole beyond
981 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
983 sack_scoreboard_hole_t *hole;
984 hole = scoreboard_first_hole (&tc->sack_sb);
985 return (!hole || (seq_geq (hole->start, tc->snd_una)
986 && seq_lt (hole->end, tc->snd_nxt)));
989 #ifndef CLIB_MARCH_VARIANT
992 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
994 sack_scoreboard_hole_t *hole, *next_hole;
995 sack_scoreboard_t *sb = &tc->sack_sb;
996 sack_block_t *blk, *rcv_sacks;
997 u32 blk_index = 0, i, j;
1000 sb->last_sacked_bytes = 0;
1001 sb->last_bytes_delivered = 0;
1004 if (!tcp_opts_sack (&tc->rcv_opts)
1005 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1008 has_rxt = tcp_in_cong_recovery (tc);
1010 /* Remove invalid blocks */
1011 blk = tc->rcv_opts.sacks;
1012 while (blk < vec_end (tc->rcv_opts.sacks))
1014 if (seq_lt (blk->start, blk->end)
1015 && seq_gt (blk->start, tc->snd_una)
1016 && seq_gt (blk->start, ack)
1017 && seq_lt (blk->start, tc->snd_nxt)
1018 && seq_leq (blk->end, tc->snd_nxt))
1023 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
1026 /* Add block for cumulative ack */
1027 if (seq_gt (ack, tc->snd_una))
1029 vec_add2 (tc->rcv_opts.sacks, blk, 1);
1030 blk->start = tc->snd_una;
1034 if (vec_len (tc->rcv_opts.sacks) == 0)
1037 tcp_scoreboard_trace_add (tc, ack);
1039 /* Make sure blocks are ordered */
1040 rcv_sacks = tc->rcv_opts.sacks;
1041 for (i = 0; i < vec_len (rcv_sacks); i++)
1042 for (j = i + 1; j < vec_len (rcv_sacks); j++)
1043 if (seq_lt (rcv_sacks[j].start, rcv_sacks[i].start))
1045 sack_block_t tmp = rcv_sacks[i];
1046 rcv_sacks[i] = rcv_sacks[j];
1050 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1052 /* Handle reneging as a special case */
1053 if (PREDICT_FALSE (sb->is_reneging))
1055 /* No holes, only sacked bytes */
1056 if (seq_leq (tc->snd_nxt, sb->high_sacked))
1058 /* No progress made so return */
1059 if (seq_leq (ack, tc->snd_una))
1062 /* Update sacked bytes delivered and return */
1063 sb->last_bytes_delivered = ack - tc->snd_una;
1064 sb->sacked_bytes -= sb->last_bytes_delivered;
1065 sb->is_reneging = seq_lt (ack, sb->high_sacked);
1069 /* New hole above high sacked. Add it and process normally */
1070 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1071 sb->high_sacked, tc->snd_nxt);
1072 sb->tail = scoreboard_hole_index (sb, hole);
1074 /* Not reneging and no holes. Insert the first that covers all
1075 * outstanding bytes */
1078 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1079 tc->snd_una, tc->snd_nxt);
1080 sb->tail = scoreboard_hole_index (sb, hole);
1082 sb->high_sacked = rcv_sacks[vec_len (rcv_sacks) - 1].end;
1086 /* If we have holes but snd_nxt is beyond the last hole, update
1087 * last hole end or add new hole after high sacked */
1088 hole = scoreboard_last_hole (sb);
1089 if (seq_gt (tc->snd_nxt, hole->end))
1091 if (seq_geq (hole->start, sb->high_sacked))
1093 hole->end = tc->snd_nxt;
1095 /* New hole after high sacked block */
1096 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1098 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1103 /* Keep track of max byte sacked for when the last hole
1105 sb->high_sacked = seq_max (rcv_sacks[vec_len (rcv_sacks) - 1].end,
1109 /* Walk the holes with the SACK blocks */
1110 hole = pool_elt_at_index (sb->holes, sb->head);
1112 if (PREDICT_FALSE (sb->is_reneging))
1113 sb->last_bytes_delivered += hole->start - tc->snd_una;
1115 while (hole && blk_index < vec_len (rcv_sacks))
1117 blk = &rcv_sacks[blk_index];
1118 if (seq_leq (blk->start, hole->start))
1120 /* Block covers hole. Remove hole */
1121 if (seq_geq (blk->end, hole->end))
1123 next_hole = scoreboard_next_hole (sb, hole);
1125 /* If covered by ack, compute delivered bytes */
1126 if (blk->end == ack)
1128 u32 sacked = next_hole ? next_hole->start : sb->high_sacked;
1129 if (PREDICT_FALSE (seq_lt (ack, sacked)))
1131 sb->last_bytes_delivered += ack - hole->end;
1132 sb->is_reneging = 1;
1136 sb->last_bytes_delivered += sacked - hole->end;
1137 sb->is_reneging = 0;
1140 scoreboard_update_sacked_rxt (sb, hole->start, hole->end,
1142 scoreboard_remove_hole (sb, hole);
1145 /* Partial 'head' overlap */
1148 if (seq_gt (blk->end, hole->start))
1150 scoreboard_update_sacked_rxt (sb, hole->start, blk->end,
1152 hole->start = blk->end;
1159 /* Hole must be split */
1160 if (seq_lt (blk->end, hole->end))
1162 u32 hole_index = scoreboard_hole_index (sb, hole);
1163 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1165 /* Pool might've moved */
1166 hole = scoreboard_get_hole (sb, hole_index);
1167 hole->end = blk->start;
1169 scoreboard_update_sacked_rxt (sb, blk->start, blk->end,
1173 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1175 else if (seq_lt (blk->start, hole->end))
1177 scoreboard_update_sacked_rxt (sb, blk->start, hole->end,
1179 hole->end = blk->start;
1181 hole = scoreboard_next_hole (sb, hole);
1185 scoreboard_update_bytes (sb, ack, tc->snd_mss);
1187 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1188 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1189 || sb->sacked_bytes <= tc->snd_nxt - seq_max (tc->snd_una, ack));
1190 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1191 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1192 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1193 || sb->is_reneging || sb->holes[sb->head].start == ack);
1194 ASSERT (sb->last_lost_bytes <= sb->lost_bytes);
1195 ASSERT ((ack - tc->snd_una) + sb->last_sacked_bytes
1196 - sb->last_bytes_delivered >= sb->rxt_sacked);
1197 ASSERT ((ack - tc->snd_una) >= tc->sack_sb.last_bytes_delivered
1198 || (tc->flags & TCP_CONN_FINSNT));
1200 TCP_EVT (TCP_EVT_CC_SCOREBOARD, tc);
1202 #endif /* CLIB_MARCH_VARIANT */
1205 * Try to update snd_wnd based on feedback received from peer.
1207 * If successful, and new window is 'effectively' 0, activate persist
1211 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1213 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1214 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1215 if (seq_lt (tc->snd_wl1, seq)
1216 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1218 tc->snd_wnd = snd_wnd;
1221 TCP_EVT (TCP_EVT_SND_WND, tc);
1223 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1225 /* Set persist timer if not set and we just got 0 wnd */
1226 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1227 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1228 tcp_persist_timer_set (tc);
1232 tcp_persist_timer_reset (tc);
1233 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1236 tcp_update_rto (tc);
1243 * Init loss recovery/fast recovery.
1245 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1246 * updated in @ref tcp_cc_handle_event after fast retransmit
1249 tcp_cc_init_congestion (tcp_connection_t * tc)
1251 tcp_fastrecovery_on (tc);
1252 tc->snd_congestion = tc->snd_nxt;
1253 tc->cwnd_acc_bytes = 0;
1254 tc->snd_rxt_bytes = 0;
1255 tc->rxt_delivered = 0;
1256 tc->prr_delivered = 0;
1257 tc->prr_start = tc->snd_una;
1258 tc->prev_ssthresh = tc->ssthresh;
1259 tc->prev_cwnd = tc->cwnd;
1261 tc->snd_rxt_ts = tcp_tstamp (tc);
1262 tcp_cc_congestion (tc);
1264 /* Post retransmit update cwnd to ssthresh and account for the
1265 * three segments that have left the network and should've been
1266 * buffered at the receiver XXX */
1267 if (!tcp_opts_sack_permitted (&tc->rcv_opts))
1268 tc->cwnd += 3 * tc->snd_mss;
1270 tc->fr_occurences += 1;
1271 TCP_EVT (TCP_EVT_CC_EVT, tc, 4);
1275 tcp_cc_congestion_undo (tcp_connection_t * tc)
1277 tc->cwnd = tc->prev_cwnd;
1278 tc->ssthresh = tc->prev_ssthresh;
1279 tcp_cc_undo_recovery (tc);
1280 ASSERT (tc->rto_boff == 0);
1281 TCP_EVT (TCP_EVT_CC_EVT, tc, 5);
1285 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1287 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1289 && tcp_opts_tstamp (&tc->rcv_opts)
1290 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1294 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1296 return (tcp_cc_is_spurious_timeout_rxt (tc));
1300 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1302 return (tc->sack_sb.lost_bytes
1303 || ((TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
1304 < tc->sack_sb.sacked_bytes));
1308 tcp_should_fastrecover (tcp_connection_t * tc, u8 has_sack)
1312 /* If of of the two conditions lower hold, reset dupacks because
1313 * we're probably after timeout (RFC6582 heuristics).
1314 * If Cumulative ack does not cover more than congestion threshold,
1316 * 1) The following doesn't hold: The congestion window is greater
1317 * than SMSS bytes and the difference between highest_ack
1318 * and prev_highest_ack is at most 4*SMSS bytes
1319 * 2) Echoed timestamp in the last non-dup ack does not equal the
1322 if (seq_leq (tc->snd_una, tc->snd_congestion)
1323 && ((!(tc->cwnd > tc->snd_mss
1324 && tc->bytes_acked <= 4 * tc->snd_mss))
1325 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1327 tc->rcv_dupacks = 0;
1331 return ((tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1332 || tcp_should_fastrecover_sack (tc));
1336 tcp_cc_recover (tcp_connection_t * tc)
1338 sack_scoreboard_hole_t *hole;
1341 ASSERT (tcp_in_cong_recovery (tc));
1343 if (tcp_cc_is_spurious_retransmit (tc))
1345 tcp_cc_congestion_undo (tc);
1349 tc->rcv_dupacks = 0;
1350 tc->prr_delivered = 0;
1351 tc->rxt_delivered = 0;
1352 tc->snd_rxt_bytes = 0;
1355 tc->flags &= ~TCP_CONN_RXT_PENDING;
1357 tcp_connection_tx_pacer_reset (tc, tc->cwnd, 0 /* start bucket */ );
1359 /* Previous recovery left us congested. Continue sending as part
1360 * of the current recovery event with an updated snd_congestion */
1361 if (tc->sack_sb.sacked_bytes)
1363 tc->snd_congestion = tc->snd_nxt;
1364 tc->snd_rxt_ts = tcp_tstamp (tc);
1365 tc->prr_start = tc->snd_una;
1366 scoreboard_init_rxt (&tc->sack_sb, tc->snd_una);
1367 tcp_program_retransmit (tc);
1371 hole = scoreboard_first_hole (&tc->sack_sb);
1372 if (hole && hole->start == tc->snd_una && hole->end == tc->snd_nxt)
1373 scoreboard_clear (&tc->sack_sb);
1375 if (!tcp_in_recovery (tc) && !is_spurious)
1376 tcp_cc_recovered (tc);
1378 tcp_fastrecovery_off (tc);
1379 tcp_fastrecovery_first_off (tc);
1380 tcp_recovery_off (tc);
1381 TCP_EVT (TCP_EVT_CC_EVT, tc, 3);
1383 ASSERT (tc->rto_boff == 0);
1384 ASSERT (!tcp_in_cong_recovery (tc));
1385 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1390 tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1392 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1394 /* Congestion avoidance */
1395 tcp_cc_rcv_ack (tc, rs);
1397 /* If a cumulative ack, make sure dupacks is 0 */
1398 tc->rcv_dupacks = 0;
1400 /* When dupacks hits the threshold we only enter fast retransmit if
1401 * cumulative ack covers more than snd_congestion. Should snd_una
1402 * wrap this test may fail under otherwise valid circumstances.
1403 * Therefore, proactively update snd_congestion when wrap detected. */
1405 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1406 && seq_gt (tc->snd_congestion, tc->snd_una)))
1407 tc->snd_congestion = tc->snd_una - 1;
1411 * One function to rule them all ... and in the darkness bind them
1414 tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs,
1417 u8 has_sack = tcp_opts_sack_permitted (&tc->rcv_opts);
1420 * If not in recovery, figure out if we should enter
1422 if (!tcp_in_cong_recovery (tc))
1427 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1428 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1430 if (tcp_should_fastrecover (tc, has_sack))
1432 tcp_cc_init_congestion (tc);
1435 scoreboard_init_rxt (&tc->sack_sb, tc->snd_una);
1437 tcp_connection_tx_pacer_reset (tc, tc->cwnd, 0 /* start bucket */ );
1438 tcp_program_retransmit (tc);
1445 * Already in recovery. See if we can exit and stop retransmitting
1448 if (seq_geq (tc->snd_una, tc->snd_congestion))
1450 /* If spurious return, we've already updated everything */
1451 if (tcp_cc_recover (tc))
1453 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1457 /* Treat as congestion avoidance ack */
1458 tcp_cc_rcv_ack (tc, rs);
1463 * Process (re)transmit feedback. Output path uses this to decide how much
1464 * more data to release into the network
1468 tc->rxt_delivered += tc->sack_sb.rxt_sacked;
1469 tc->prr_delivered += tc->bytes_acked + tc->sack_sb.last_sacked_bytes
1470 - tc->sack_sb.last_bytes_delivered;
1472 tcp_program_retransmit (tc);
1478 tc->rcv_dupacks += 1;
1479 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1481 tc->rxt_delivered = clib_max (tc->rxt_delivered + tc->bytes_acked,
1484 tc->prr_delivered += 1;
1486 tc->prr_delivered += tc->bytes_acked - tc->snd_mss * tc->rcv_dupacks;
1488 /* If partial ack, assume that the first un-acked segment was lost */
1489 if (tc->bytes_acked || tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1490 tcp_fastrecovery_first_on (tc);
1492 tcp_program_retransmit (tc);
1496 * Notify cc of the event
1499 if (!tc->bytes_acked)
1501 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1505 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1506 * reset dupacks to 0. Also needed if in congestion recovery */
1507 tc->rcv_dupacks = 0;
1509 if (tcp_in_recovery (tc))
1510 tcp_cc_rcv_ack (tc, rs);
1512 tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs);
1516 * Check if duplicate ack as per RFC5681 Sec. 2
1519 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
1522 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
1523 && seq_gt (tc->snd_nxt, tc->snd_una)
1524 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
1525 && (prev_snd_wnd == tc->snd_wnd));
1529 * Checks if ack is a congestion control event.
1532 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
1533 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
1535 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
1536 * defined to be 'duplicate' as well */
1537 *is_dack = tc->sack_sb.last_sacked_bytes
1538 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
1540 /* If reneging, wait for timer based retransmits */
1541 if (PREDICT_FALSE (tcp_is_lost_fin (tc) || tc->sack_sb.is_reneging))
1544 return (*is_dack || tcp_in_cong_recovery (tc));
1548 * Process incoming ACK
1551 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1552 tcp_header_t * th, u32 * error)
1554 u32 prev_snd_wnd, prev_snd_una;
1555 tcp_rate_sample_t rs = { 0 };
1558 TCP_EVT (TCP_EVT_CC_STAT, tc);
1560 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1561 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1563 /* We've probably entered recovery and the peer still has some
1564 * of the data we've sent. Update snd_nxt and accept the ack */
1565 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1566 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1568 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1572 tc->errors.above_ack_wnd += 1;
1573 *error = TCP_ERROR_ACK_FUTURE;
1574 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 0, vnet_buffer (b)->tcp.ack_number);
1578 /* If old ACK, probably it's an old dupack */
1579 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1581 tc->errors.below_ack_wnd += 1;
1582 *error = TCP_ERROR_ACK_OLD;
1583 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 1, vnet_buffer (b)->tcp.ack_number);
1584 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1585 tcp_cc_handle_event (tc, 0, 1);
1586 /* Don't drop yet */
1593 * Looks okay, process feedback
1596 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1597 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1599 prev_snd_wnd = tc->snd_wnd;
1600 prev_snd_una = tc->snd_una;
1601 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1602 vnet_buffer (b)->tcp.ack_number,
1603 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1604 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1605 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
1606 tcp_validate_txf_size (tc, tc->bytes_acked);
1608 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
1609 tcp_bt_sample_delivery_rate (tc, &rs);
1611 tcp_program_dequeue (wrk, tc);
1613 if (tc->bytes_acked)
1614 tcp_update_rtt (tc, &rs, vnet_buffer (b)->tcp.ack_number);
1616 TCP_EVT (TCP_EVT_ACK_RCVD, tc);
1619 * Check if we have congestion event
1622 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1624 tcp_cc_handle_event (tc, &rs, is_dack);
1625 tc->dupacks_in += is_dack;
1626 if (!tcp_in_cong_recovery (tc))
1628 *error = TCP_ERROR_ACK_OK;
1631 *error = TCP_ERROR_ACK_DUP;
1632 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1638 * Update congestion control (slow start/congestion avoidance)
1640 tcp_cc_update (tc, &rs);
1641 *error = TCP_ERROR_ACK_OK;
1646 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1648 if (!tcp_disconnect_pending (tc))
1650 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1651 tcp_disconnect_pending_on (tc);
1656 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1658 u32 thread_index, *pending_disconnects;
1659 tcp_connection_t *tc;
1662 if (!vec_len (wrk->pending_disconnects))
1665 thread_index = wrk->vm->thread_index;
1666 pending_disconnects = wrk->pending_disconnects;
1667 for (i = 0; i < vec_len (pending_disconnects); i++)
1669 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1670 tcp_disconnect_pending_off (tc);
1671 session_transport_closing_notify (&tc->connection);
1673 _vec_len (wrk->pending_disconnects) = 0;
1677 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1680 /* Reject out-of-order fins */
1681 if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt)
1684 /* Account for the FIN and send ack */
1686 tcp_program_ack (tc);
1687 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1688 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1689 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1690 tcp_program_disconnect (wrk, tc);
1691 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
1692 TCP_EVT (TCP_EVT_FIN_RCVD, tc);
1693 *error = TCP_ERROR_FIN_RCVD;
1696 #ifndef CLIB_MARCH_VARIANT
1698 tcp_sack_vector_is_sane (sack_block_t * sacks)
1701 for (i = 1; i < vec_len (sacks); i++)
1703 if (sacks[i - 1].end == sacks[i].start)
1710 * Build SACK list as per RFC2018.
1712 * Makes sure the first block contains the segment that generated the current
1713 * ACK and the following ones are the ones most recently reported in SACK
1716 * @param tc TCP connection for which the SACK list is updated
1717 * @param start Start sequence number of the newest SACK block
1718 * @param end End sequence of the newest SACK block
1721 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1723 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1726 /* If the first segment is ooo add it to the list. Last write might've moved
1727 * rcv_nxt over the first segment. */
1728 if (seq_lt (tc->rcv_nxt, start))
1730 vec_add2 (new_list, block, 1);
1731 block->start = start;
1735 /* Find the blocks still worth keeping. */
1736 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1738 /* Discard if rcv_nxt advanced beyond current block */
1739 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1742 /* Merge or drop if segment overlapped by the new segment */
1743 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1744 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1746 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1747 new_list[0].start = tc->snd_sacks[i].start;
1748 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1749 new_list[0].end = tc->snd_sacks[i].end;
1753 /* Save to new SACK list if we have space. */
1754 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1755 vec_add1 (new_list, tc->snd_sacks[i]);
1758 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1760 /* Replace old vector with new one */
1761 vec_reset_length (tc->snd_sacks);
1762 tc->snd_sacks_fl = tc->snd_sacks;
1763 tc->snd_sacks = new_list;
1765 /* Segments should not 'touch' */
1766 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1770 tcp_sack_list_bytes (tcp_connection_t * tc)
1773 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1774 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1777 #endif /* CLIB_MARCH_VARIANT */
1779 /** Enqueue data for delivery to application */
1781 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1784 int written, error = TCP_ERROR_ENQUEUED;
1786 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1788 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1789 1 /* queue event */ , 1);
1790 tc->bytes_in += written;
1792 TCP_EVT (TCP_EVT_INPUT, tc, 0, data_len, written);
1794 /* Update rcv_nxt */
1795 if (PREDICT_TRUE (written == data_len))
1797 tc->rcv_nxt += written;
1799 /* If more data written than expected, account for out-of-order bytes. */
1800 else if (written > data_len)
1802 tc->rcv_nxt += written;
1803 TCP_EVT (TCP_EVT_CC_INPUT, tc, data_len, written);
1805 else if (written > 0)
1807 /* We've written something but FIFO is probably full now */
1808 tc->rcv_nxt += written;
1809 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1813 return TCP_ERROR_FIFO_FULL;
1816 /* Update SACK list if need be */
1817 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1819 /* Remove SACK blocks that have been delivered */
1820 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1826 /** Enqueue out-of-order data */
1828 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1834 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1837 /* Enqueue out-of-order data with relative offset */
1838 rv = session_enqueue_stream_connection (&tc->connection, b,
1839 vnet_buffer (b)->tcp.seq_number -
1840 tc->rcv_nxt, 0 /* queue event */ ,
1843 /* Nothing written */
1846 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, 0);
1847 return TCP_ERROR_FIFO_FULL;
1850 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1851 tc->bytes_in += data_len;
1853 /* Update SACK list if in use */
1854 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1856 ooo_segment_t *newest;
1859 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1861 /* Get the newest segment from the fifo */
1862 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1865 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1866 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1867 start = tc->rcv_nxt + offset;
1868 end = start + ooo_segment_length (s0->rx_fifo, newest);
1869 tcp_update_sack_list (tc, start, end);
1870 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1871 TCP_EVT (TCP_EVT_CC_SACKS, tc);
1875 return TCP_ERROR_ENQUEUED_OOO;
1879 * Check if ACK could be delayed. If ack can be delayed, it should return
1880 * true for a full frame. If we're always acking return 0.
1883 tcp_can_delack (tcp_connection_t * tc)
1885 /* Send ack if ... */
1887 /* just sent a rcv wnd 0
1888 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1889 /* constrained to send ack */
1890 || (tc->flags & TCP_CONN_SNDACK) != 0
1891 /* we're almost out of tx wnd */
1892 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1899 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1901 u32 discard, first = b->current_length;
1902 vlib_main_t *vm = vlib_get_main ();
1904 /* Handle multi-buffer segments */
1905 if (n_bytes_to_drop > b->current_length)
1907 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1911 discard = clib_min (n_bytes_to_drop, b->current_length);
1912 vlib_buffer_advance (b, discard);
1913 b = vlib_get_buffer (vm, b->next_buffer);
1914 n_bytes_to_drop -= discard;
1916 while (n_bytes_to_drop);
1917 if (n_bytes_to_drop > first)
1918 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1921 vlib_buffer_advance (b, n_bytes_to_drop);
1922 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1927 * Receive buffer for connection and handle acks
1929 * It handles both in order or out-of-order data.
1932 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1935 u32 error, n_bytes_to_drop, n_data_bytes;
1937 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1938 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1939 ASSERT (n_data_bytes);
1940 tc->data_segs_in += 1;
1942 /* Handle out-of-order data */
1943 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1945 /* Old sequence numbers allowed through because they overlapped
1947 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1949 /* Completely in the past (possible retransmit). Ack
1950 * retransmissions since we may not have any data to send */
1951 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1953 tcp_program_ack (tc);
1954 error = TCP_ERROR_SEGMENT_OLD;
1958 /* Chop off the bytes in the past and see if what is left
1959 * can be enqueued in order */
1960 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1961 n_data_bytes -= n_bytes_to_drop;
1962 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1963 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1965 error = TCP_ERROR_SEGMENT_OLD;
1971 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1972 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1973 tcp_program_dupack (tc);
1974 TCP_EVT (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1975 tc->errors.above_data_wnd += seq_gt (vnet_buffer (b)->tcp.seq_end,
1976 tc->rcv_las + tc->rcv_wnd);
1982 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1983 * segments can be enqueued after fifo tail offset changes. */
1984 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1985 if (tcp_can_delack (tc))
1987 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1988 tcp_timer_set (tc, TCP_TIMER_DELACK, tcp_cfg.delack_time);
1992 tcp_program_ack (tc);
2000 tcp_header_t tcp_header;
2001 tcp_connection_t tcp_connection;
2005 format_tcp_rx_trace (u8 * s, va_list * args)
2007 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2008 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2009 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2010 u32 indent = format_get_indent (s);
2012 s = format (s, "%U\n%U%U",
2013 format_tcp_header, &t->tcp_header, 128,
2014 format_white_space, indent,
2015 format_tcp_connection, &t->tcp_connection, 1);
2021 format_tcp_rx_trace_short (u8 * s, va_list * args)
2023 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2024 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2025 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2027 s = format (s, "%d -> %d (%U)",
2028 clib_net_to_host_u16 (t->tcp_header.dst_port),
2029 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2030 t->tcp_connection.state);
2036 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2037 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2041 clib_memcpy_fast (&t0->tcp_connection, tc0,
2042 sizeof (t0->tcp_connection));
2046 th0 = tcp_buffer_hdr (b0);
2048 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2052 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2053 vlib_frame_t * frame, u8 is_ip4)
2057 n_left = frame->n_vectors;
2058 from = vlib_frame_vector_args (frame);
2062 tcp_connection_t *tc0;
2069 b0 = vlib_get_buffer (vm, bi0);
2071 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2073 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2074 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2076 th0 = tcp_buffer_hdr (b0);
2077 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2086 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2087 u8 is_ip4, u32 evt, u32 val)
2090 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2092 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2095 #define tcp_maybe_inc_counter(node_id, err, count) \
2097 if (next0 != tcp_next_drop (is_ip4)) \
2098 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2099 tcp6_##node_id##_node.index, is_ip4, err, \
2102 #define tcp_inc_counter(node_id, err, count) \
2103 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2104 tcp6_##node_id##_node.index, is_ip4, \
2106 #define tcp_maybe_inc_err_counter(cnts, err) \
2108 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2110 #define tcp_inc_err_counter(cnts, err, val) \
2114 #define tcp_store_err_counters(node_id, cnts) \
2117 for (i = 0; i < TCP_N_ERROR; i++) \
2119 tcp_inc_counter(node_id, i, cnts[i]); \
2124 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2125 vlib_frame_t * frame, int is_ip4)
2127 u32 thread_index = vm->thread_index, errors = 0;
2128 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2129 u32 n_left_from, *from, *first_buffer;
2130 u16 err_counters[TCP_N_ERROR] = { 0 };
2132 if (node->flags & VLIB_NODE_FLAG_TRACE)
2133 tcp_established_trace_frame (vm, node, frame, is_ip4);
2135 first_buffer = from = vlib_frame_vector_args (frame);
2136 n_left_from = frame->n_vectors;
2138 while (n_left_from > 0)
2140 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2143 tcp_connection_t *tc0;
2145 if (n_left_from > 1)
2148 pb = vlib_get_buffer (vm, from[1]);
2149 vlib_prefetch_buffer_header (pb, LOAD);
2150 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2157 b0 = vlib_get_buffer (vm, bi0);
2158 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2161 if (PREDICT_FALSE (tc0 == 0))
2163 error0 = TCP_ERROR_INVALID_CONNECTION;
2167 th0 = tcp_buffer_hdr (b0);
2169 /* TODO header prediction fast path */
2171 /* 1-4: check SEQ, RST, SYN */
2172 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2174 TCP_EVT (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2178 /* 5: check the ACK field */
2179 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2182 /* 6: check the URG bit TODO */
2184 /* 7: process the segment text */
2185 if (vnet_buffer (b0)->tcp.data_len)
2186 error0 = tcp_segment_rcv (wrk, tc0, b0);
2188 /* 8: check the FIN bit */
2189 if (PREDICT_FALSE (tcp_is_fin (th0)))
2190 tcp_rcv_fin (wrk, tc0, b0, &error0);
2193 tcp_inc_err_counter (err_counters, error0, 1);
2196 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2198 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2199 tcp_store_err_counters (established, err_counters);
2200 tcp_handle_postponed_dequeues (wrk);
2201 tcp_handle_disconnects (wrk);
2202 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2204 return frame->n_vectors;
2207 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2208 vlib_node_runtime_t * node,
2209 vlib_frame_t * from_frame)
2211 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2214 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2215 vlib_node_runtime_t * node,
2216 vlib_frame_t * from_frame)
2218 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2222 VLIB_REGISTER_NODE (tcp4_established_node) =
2224 .name = "tcp4-established",
2225 /* Takes a vector of packets. */
2226 .vector_size = sizeof (u32),
2227 .n_errors = TCP_N_ERROR,
2228 .error_strings = tcp_error_strings,
2229 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2232 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2233 foreach_tcp_state_next
2236 .format_trace = format_tcp_rx_trace_short,
2241 VLIB_REGISTER_NODE (tcp6_established_node) =
2243 .name = "tcp6-established",
2244 /* Takes a vector of packets. */
2245 .vector_size = sizeof (u32),
2246 .n_errors = TCP_N_ERROR,
2247 .error_strings = tcp_error_strings,
2248 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2251 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2252 foreach_tcp_state_next
2255 .format_trace = format_tcp_rx_trace_short,
2261 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2263 transport_connection_t *tmp = 0;
2270 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2273 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2274 && (tc->state == TCP_STATE_LISTEN
2275 || tc->c_rmt_port == hdr->src_port));
2279 handle = session_lookup_half_open_handle (&tc->connection);
2280 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2281 tc->c_proto, tc->c_is_ip4);
2285 if (tmp->lcl_port == hdr->dst_port
2286 && tmp->rmt_port == hdr->src_port)
2288 TCP_DBG ("half-open is valid!");
2296 * Lookup transport connection
2298 static tcp_connection_t *
2299 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2303 transport_connection_t *tconn;
2304 tcp_connection_t *tc;
2309 ip4 = vlib_buffer_get_current (b);
2310 tcp = ip4_next_header (ip4);
2311 tconn = session_lookup_connection_wt4 (fib_index,
2316 TRANSPORT_PROTO_TCP,
2317 thread_index, &is_filtered);
2318 tc = tcp_get_connection_from_transport (tconn);
2319 ASSERT (tcp_lookup_is_valid (tc, tcp));
2324 ip6 = vlib_buffer_get_current (b);
2325 tcp = ip6_next_header (ip6);
2326 tconn = session_lookup_connection_wt6 (fib_index,
2331 TRANSPORT_PROTO_TCP,
2332 thread_index, &is_filtered);
2333 tc = tcp_get_connection_from_transport (tconn);
2334 ASSERT (tcp_lookup_is_valid (tc, tcp));
2340 tcp_check_tx_offload (tcp_connection_t * tc, int is_ipv4)
2342 vnet_main_t *vnm = vnet_get_main ();
2343 const dpo_id_t *dpo;
2344 const load_balance_t *lb;
2345 vnet_hw_interface_t *hw_if;
2346 u32 sw_if_idx, lb_idx;
2350 ip4_address_t *dst_addr = &(tc->c_rmt_ip.ip4);
2351 lb_idx = ip4_fib_forwarding_lookup (tc->c_fib_index, dst_addr);
2355 ip6_address_t *dst_addr = &(tc->c_rmt_ip.ip6);
2356 lb_idx = ip6_fib_table_fwding_lookup (tc->c_fib_index, dst_addr);
2359 lb = load_balance_get (lb_idx);
2360 dpo = load_balance_get_bucket_i (lb, 0);
2362 sw_if_idx = dpo->dpoi_index;
2363 hw_if = vnet_get_sup_hw_interface (vnm, sw_if_idx);
2365 if (hw_if->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO)
2366 tc->cfg_flags |= TCP_CFG_F_TSO;
2370 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2371 vlib_frame_t * from_frame, int is_ip4)
2373 u32 n_left_from, *from, *first_buffer, errors = 0;
2374 u32 my_thread_index = vm->thread_index;
2375 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2377 from = first_buffer = vlib_frame_vector_args (from_frame);
2378 n_left_from = from_frame->n_vectors;
2380 while (n_left_from > 0)
2382 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2383 tcp_connection_t *tc0, *new_tc0;
2384 tcp_header_t *tcp0 = 0;
2392 b0 = vlib_get_buffer (vm, bi0);
2394 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2395 if (PREDICT_FALSE (tc0 == 0))
2397 error0 = TCP_ERROR_INVALID_CONNECTION;
2401 /* Half-open completed recently but the connection was't removed
2402 * yet by the owning thread */
2403 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2405 /* Make sure the connection actually exists */
2406 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2407 my_thread_index, is_ip4));
2408 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2412 ack0 = vnet_buffer (b0)->tcp.ack_number;
2413 seq0 = vnet_buffer (b0)->tcp.seq_number;
2414 tcp0 = tcp_buffer_hdr (b0);
2416 /* Crude check to see if the connection handle does not match
2417 * the packet. Probably connection just switched to established */
2418 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2419 || tcp0->src_port != tc0->c_rmt_port))
2421 error0 = TCP_ERROR_INVALID_CONNECTION;
2425 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2426 && !tcp_syn (tcp0)))
2428 error0 = TCP_ERROR_SEGMENT_INVALID;
2432 /* SYNs consume sequence numbers */
2433 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2436 * 1. check the ACK bit
2440 * If the ACK bit is set
2441 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2442 * the RST bit is set, if so drop the segment and return)
2443 * <SEQ=SEG.ACK><CTL=RST>
2444 * and discard the segment. Return.
2445 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2449 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2451 if (!tcp_rst (tcp0))
2452 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2453 error0 = TCP_ERROR_RCV_WND;
2457 /* Make sure ACK is valid */
2458 if (seq_gt (tc0->snd_una, ack0))
2460 error0 = TCP_ERROR_ACK_INVALID;
2466 * 2. check the RST bit
2471 /* If ACK is acceptable, signal client that peer is not
2472 * willing to accept connection and drop connection*/
2474 tcp_connection_reset (tc0);
2475 error0 = TCP_ERROR_RST_RCVD;
2480 * 3. check the security and precedence (skipped)
2484 * 4. check the SYN bit
2487 /* No SYN flag. Drop. */
2488 if (!tcp_syn (tcp0))
2490 error0 = TCP_ERROR_SEGMENT_INVALID;
2495 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2497 error0 = TCP_ERROR_OPTIONS;
2501 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2502 * current thread pool. */
2503 new_tc0 = tcp_connection_alloc_w_base (my_thread_index, tc0);
2504 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2505 new_tc0->irs = seq0;
2506 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2507 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2509 /* If this is not the owning thread, wait for syn retransmit to
2510 * expire and cleanup then */
2511 if (tcp_half_open_connection_cleanup (tc0))
2512 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2514 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2516 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2517 new_tc0->tsval_recent_age = tcp_time_now ();
2520 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2521 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2523 new_tc0->rcv_wscale = 0;
2525 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2526 << new_tc0->snd_wscale;
2527 new_tc0->snd_wl1 = seq0;
2528 new_tc0->snd_wl2 = ack0;
2530 tcp_connection_init_vars (new_tc0);
2532 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2533 if (PREDICT_TRUE (tcp_ack (tcp0)))
2535 /* Our SYN is ACKed: we have iss < ack = snd_una */
2537 /* TODO Dequeue acknowledged segments if we support Fast Open */
2538 new_tc0->snd_una = ack0;
2539 new_tc0->state = TCP_STATE_ESTABLISHED;
2541 /* Make sure las is initialized for the wnd computation */
2542 new_tc0->rcv_las = new_tc0->rcv_nxt;
2544 /* Notify app that we have connection. If session layer can't
2545 * allocate session send reset */
2546 if (session_stream_connect_notify (&new_tc0->connection, 0))
2548 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2549 tcp_connection_cleanup (new_tc0);
2550 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2554 new_tc0->tx_fifo_size =
2555 transport_tx_fifo_size (&new_tc0->connection);
2556 /* Update rtt with the syn-ack sample */
2557 tcp_estimate_initial_rtt (new_tc0);
2558 TCP_EVT (TCP_EVT_SYNACK_RCVD, new_tc0);
2559 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2561 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2564 new_tc0->state = TCP_STATE_SYN_RCVD;
2566 /* Notify app that we have connection */
2567 if (session_stream_connect_notify (&new_tc0->connection, 0))
2569 tcp_connection_cleanup (new_tc0);
2570 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2571 TCP_EVT (TCP_EVT_RST_SENT, tc0);
2572 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2576 new_tc0->tx_fifo_size =
2577 transport_tx_fifo_size (&new_tc0->connection);
2578 new_tc0->rtt_ts = 0;
2579 tcp_init_snd_vars (new_tc0);
2580 tcp_send_synack (new_tc0);
2581 error0 = TCP_ERROR_SYNS_RCVD;
2585 if (!(new_tc0->cfg_flags & TCP_CFG_F_NO_TSO))
2586 tcp_check_tx_offload (new_tc0, is_ip4);
2588 /* Read data, if any */
2589 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2591 clib_warning ("rcvd data in syn-sent");
2592 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2593 if (error0 == TCP_ERROR_ACK_OK)
2594 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2598 tcp_program_ack (new_tc0);
2603 tcp_inc_counter (syn_sent, error0, 1);
2604 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2606 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2607 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2608 clib_memcpy_fast (&t0->tcp_connection, tc0,
2609 sizeof (t0->tcp_connection));
2613 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2615 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2616 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2618 return from_frame->n_vectors;
2621 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2622 vlib_node_runtime_t * node,
2623 vlib_frame_t * from_frame)
2625 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2628 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2629 vlib_node_runtime_t * node,
2630 vlib_frame_t * from_frame)
2632 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2636 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2638 .name = "tcp4-syn-sent",
2639 /* Takes a vector of packets. */
2640 .vector_size = sizeof (u32),
2641 .n_errors = TCP_N_ERROR,
2642 .error_strings = tcp_error_strings,
2643 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2646 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2647 foreach_tcp_state_next
2650 .format_trace = format_tcp_rx_trace_short,
2655 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2657 .name = "tcp6-syn-sent",
2658 /* Takes a vector of packets. */
2659 .vector_size = sizeof (u32),
2660 .n_errors = TCP_N_ERROR,
2661 .error_strings = tcp_error_strings,
2662 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2665 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2666 foreach_tcp_state_next
2669 .format_trace = format_tcp_rx_trace_short,
2674 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2675 * as per RFC793 p. 64
2678 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2679 vlib_frame_t * from_frame, int is_ip4)
2681 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2682 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2683 u32 n_left_from, *from, max_dequeue;
2685 from = first_buffer = vlib_frame_vector_args (from_frame);
2686 n_left_from = from_frame->n_vectors;
2688 while (n_left_from > 0)
2690 u32 bi0, error0 = TCP_ERROR_NONE;
2691 tcp_header_t *tcp0 = 0;
2692 tcp_connection_t *tc0;
2700 b0 = vlib_get_buffer (vm, bi0);
2701 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2703 if (PREDICT_FALSE (tc0 == 0))
2705 error0 = TCP_ERROR_INVALID_CONNECTION;
2709 tcp0 = tcp_buffer_hdr (b0);
2710 is_fin0 = tcp_is_fin (tcp0);
2714 tcp_connection_t *tmp;
2715 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2717 if (tmp->state != tc0->state)
2719 if (tc0->state != TCP_STATE_CLOSED)
2720 clib_warning ("state changed");
2726 * Special treatment for CLOSED
2728 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2730 error0 = TCP_ERROR_CONNECTION_CLOSED;
2735 * For all other states (except LISTEN)
2738 /* 1-4: check SEQ, RST, SYN */
2739 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2742 /* 5: check the ACK field */
2745 case TCP_STATE_SYN_RCVD:
2747 /* Make sure the segment is exactly right */
2748 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2750 tcp_connection_reset (tc0);
2751 error0 = TCP_ERROR_SEGMENT_INVALID;
2756 * If the segment acknowledgment is not acceptable, form a
2758 * <SEQ=SEG.ACK><CTL=RST>
2761 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2763 tcp_connection_reset (tc0);
2767 /* Update rtt and rto */
2768 tcp_estimate_initial_rtt (tc0);
2769 tcp_connection_tx_pacer_update (tc0);
2771 /* Switch state to ESTABLISHED */
2772 tc0->state = TCP_STATE_ESTABLISHED;
2773 TCP_EVT (TCP_EVT_STATE_CHANGE, tc0);
2775 if (!(tc0->cfg_flags & TCP_CFG_F_NO_TSO))
2776 tcp_check_tx_offload (tc0, is_ip4);
2778 /* Initialize session variables */
2779 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2780 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2781 << tc0->rcv_opts.wscale;
2782 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2783 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2785 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2786 tcp_retransmit_timer_reset (tc0);
2787 if (session_stream_accept_notify (&tc0->connection))
2789 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2790 tcp_connection_reset (tc0);
2793 error0 = TCP_ERROR_ACK_OK;
2795 case TCP_STATE_ESTABLISHED:
2796 /* We can get packets in established state here because they
2797 * were enqueued before state change */
2798 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2802 case TCP_STATE_FIN_WAIT_1:
2803 /* In addition to the processing for the ESTABLISHED state, if
2804 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2805 * continue processing in that state. */
2806 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2809 /* Still have to send the FIN */
2810 if (tc0->flags & TCP_CONN_FINPNDG)
2812 /* TX fifo finally drained */
2813 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2814 if (max_dequeue <= tc0->burst_acked)
2816 /* If a fin was received and data was acked extend wait */
2817 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
2818 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2819 tcp_cfg.closewait_time);
2821 /* If FIN is ACKed */
2822 else if (tc0->snd_una == tc0->snd_nxt)
2824 /* Stop all retransmit timers because we have nothing more
2826 tcp_connection_timers_reset (tc0);
2828 /* We already have a FIN but didn't transition to CLOSING
2829 * because of outstanding tx data. Close the connection. */
2830 if (tc0->flags & TCP_CONN_FINRCVD)
2832 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2833 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE,
2834 tcp_cfg.cleanup_time);
2835 session_transport_closed_notify (&tc0->connection);
2839 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2840 /* Enable waitclose because we're willing to wait for peer's
2841 * FIN but not indefinitely. */
2842 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait2_time);
2844 /* Don't try to deq the FIN acked */
2845 if (tc0->burst_acked > 1)
2846 session_tx_fifo_dequeue_drop (&tc0->connection,
2847 tc0->burst_acked - 1);
2848 tc0->burst_acked = 0;
2851 case TCP_STATE_FIN_WAIT_2:
2852 /* In addition to the processing for the ESTABLISHED state, if
2853 * the retransmission queue is empty, the user's CLOSE can be
2854 * acknowledged ("ok") but do not delete the TCB. */
2855 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2857 tc0->burst_acked = 0;
2859 case TCP_STATE_CLOSE_WAIT:
2860 /* Do the same processing as for the ESTABLISHED state. */
2861 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2864 if (!(tc0->flags & TCP_CONN_FINPNDG))
2867 /* Still have outstanding tx data */
2868 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2869 if (max_dequeue > tc0->burst_acked)
2873 tcp_connection_timers_reset (tc0);
2874 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2875 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2877 case TCP_STATE_CLOSING:
2878 /* In addition to the processing for the ESTABLISHED state, if
2879 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2880 * otherwise ignore the segment. */
2881 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2884 if (tc0->snd_una != tc0->snd_nxt)
2887 tcp_connection_timers_reset (tc0);
2888 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2889 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2890 session_transport_closed_notify (&tc0->connection);
2894 case TCP_STATE_LAST_ACK:
2895 /* The only thing that [should] arrive in this state is an
2896 * acknowledgment of our FIN. If our FIN is now acknowledged,
2897 * delete the TCB, enter the CLOSED state, and return. */
2899 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2902 /* Apparently our ACK for the peer's FIN was lost */
2903 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2909 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2910 session_transport_closed_notify (&tc0->connection);
2912 /* Don't free the connection from the data path since
2913 * we can't ensure that we have no packets already enqueued
2914 * to output. Rely instead on the waitclose timer */
2915 tcp_connection_timers_reset (tc0);
2916 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
2921 case TCP_STATE_TIME_WAIT:
2922 /* The only thing that can arrive in this state is a
2923 * retransmission of the remote FIN. Acknowledge it, and restart
2924 * the 2 MSL timeout. */
2926 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2932 tcp_program_ack (tc0);
2933 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2941 /* 6: check the URG bit TODO */
2943 /* 7: process the segment text */
2946 case TCP_STATE_ESTABLISHED:
2947 case TCP_STATE_FIN_WAIT_1:
2948 case TCP_STATE_FIN_WAIT_2:
2949 if (vnet_buffer (b0)->tcp.data_len)
2950 error0 = tcp_segment_rcv (wrk, tc0, b0);
2952 case TCP_STATE_CLOSE_WAIT:
2953 case TCP_STATE_CLOSING:
2954 case TCP_STATE_LAST_ACK:
2955 case TCP_STATE_TIME_WAIT:
2956 /* This should not occur, since a FIN has been received from the
2957 * remote side. Ignore the segment text. */
2961 /* 8: check the FIN bit */
2965 TCP_EVT (TCP_EVT_FIN_RCVD, tc0);
2969 case TCP_STATE_ESTABLISHED:
2970 /* Account for the FIN and send ack */
2972 tcp_program_ack (tc0);
2973 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2974 tcp_program_disconnect (wrk, tc0);
2975 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
2977 case TCP_STATE_SYN_RCVD:
2978 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2979 * notified yet, set a cleanup timer instead of relying on
2980 * disconnect notify and the implicit close call. */
2981 tcp_connection_timers_reset (tc0);
2984 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2985 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2987 case TCP_STATE_CLOSE_WAIT:
2988 case TCP_STATE_CLOSING:
2989 case TCP_STATE_LAST_ACK:
2992 case TCP_STATE_FIN_WAIT_1:
2995 if (tc0->flags & TCP_CONN_FINPNDG)
2997 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
2998 * sending it. Since we already received a fin, do not wait
3000 tc0->flags |= TCP_CONN_FINRCVD;
3001 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
3002 tcp_cfg.closewait_time);
3006 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
3007 tcp_program_ack (tc0);
3008 /* Wait for ACK for our FIN but not forever */
3009 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
3010 tcp_cfg.closing_time);
3013 case TCP_STATE_FIN_WAIT_2:
3014 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
3016 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
3017 tcp_connection_timers_reset (tc0);
3018 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3019 tcp_program_ack (tc0);
3020 session_transport_closed_notify (&tc0->connection);
3022 case TCP_STATE_TIME_WAIT:
3023 /* Remain in the TIME-WAIT state. Restart the time-wait
3026 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3029 error0 = TCP_ERROR_FIN_RCVD;
3033 tcp_inc_counter (rcv_process, error0, 1);
3034 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3036 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3037 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3041 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
3043 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3044 tcp_handle_postponed_dequeues (wrk);
3045 tcp_handle_disconnects (wrk);
3046 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3048 return from_frame->n_vectors;
3051 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
3052 vlib_node_runtime_t * node,
3053 vlib_frame_t * from_frame)
3055 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3058 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
3059 vlib_node_runtime_t * node,
3060 vlib_frame_t * from_frame)
3062 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3066 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3068 .name = "tcp4-rcv-process",
3069 /* Takes a vector of packets. */
3070 .vector_size = sizeof (u32),
3071 .n_errors = TCP_N_ERROR,
3072 .error_strings = tcp_error_strings,
3073 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3076 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3077 foreach_tcp_state_next
3080 .format_trace = format_tcp_rx_trace_short,
3085 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3087 .name = "tcp6-rcv-process",
3088 /* Takes a vector of packets. */
3089 .vector_size = sizeof (u32),
3090 .n_errors = TCP_N_ERROR,
3091 .error_strings = tcp_error_strings,
3092 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3095 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3096 foreach_tcp_state_next
3099 .format_trace = format_tcp_rx_trace_short,
3104 * LISTEN state processing as per RFC 793 p. 65
3107 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3108 vlib_frame_t * from_frame, int is_ip4)
3110 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3111 u32 my_thread_index = vm->thread_index;
3113 from = first_buffer = vlib_frame_vector_args (from_frame);
3114 n_left_from = from_frame->n_vectors;
3116 while (n_left_from > 0)
3121 tcp_header_t *th0 = 0;
3122 tcp_connection_t *lc0;
3125 tcp_connection_t *child0;
3126 u32 error0 = TCP_ERROR_NONE;
3132 b0 = vlib_get_buffer (vm, bi0);
3133 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3137 ip40 = vlib_buffer_get_current (b0);
3138 th0 = ip4_next_header (ip40);
3142 ip60 = vlib_buffer_get_current (b0);
3143 th0 = ip6_next_header (ip60);
3146 /* Create child session. For syn-flood protection use filter */
3148 /* 1. first check for an RST: handled in dispatch */
3149 /* if (tcp_rst (th0))
3153 /* 2. second check for an ACK: handled in dispatch */
3154 /* if (tcp_ack (th0))
3156 tcp_send_reset (b0, is_ip4);
3161 /* 3. check for a SYN (did that already) */
3163 /* Make sure connection wasn't just created */
3164 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3166 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3168 error0 = TCP_ERROR_CREATE_EXISTS;
3172 /* Create child session and send SYN-ACK */
3173 child0 = tcp_connection_alloc (my_thread_index);
3174 child0->c_lcl_port = th0->dst_port;
3175 child0->c_rmt_port = th0->src_port;
3176 child0->c_is_ip4 = is_ip4;
3177 child0->state = TCP_STATE_SYN_RCVD;
3178 child0->c_fib_index = lc0->c_fib_index;
3179 child0->cc_algo = lc0->cc_algo;
3183 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3184 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3188 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3189 sizeof (ip6_address_t));
3190 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3191 sizeof (ip6_address_t));
3194 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3196 error0 = TCP_ERROR_OPTIONS;
3197 tcp_connection_free (child0);
3201 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3202 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3203 child0->rcv_las = child0->rcv_nxt;
3204 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3206 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3207 * segments are used to initialize PAWS. */
3208 if (tcp_opts_tstamp (&child0->rcv_opts))
3210 child0->tsval_recent = child0->rcv_opts.tsval;
3211 child0->tsval_recent_age = tcp_time_now ();
3214 if (tcp_opts_wscale (&child0->rcv_opts))
3215 child0->snd_wscale = child0->rcv_opts.wscale;
3217 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3218 << child0->snd_wscale;
3219 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3220 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3222 tcp_connection_init_vars (child0);
3223 child0->rto = TCP_RTO_MIN;
3225 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3226 lc0->c_thread_index, 0 /* notify */ ))
3228 tcp_connection_cleanup (child0);
3229 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3233 TCP_EVT (TCP_EVT_SYN_RCVD, child0, 1);
3234 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3235 tcp_send_synack (child0);
3239 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3241 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3242 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3243 clib_memcpy_fast (&t0->tcp_connection, lc0,
3244 sizeof (t0->tcp_connection));
3247 n_syns += (error0 == TCP_ERROR_NONE);
3250 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3251 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3253 return from_frame->n_vectors;
3256 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3257 vlib_frame_t * from_frame)
3259 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3262 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3263 vlib_frame_t * from_frame)
3265 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3269 VLIB_REGISTER_NODE (tcp4_listen_node) =
3271 .name = "tcp4-listen",
3272 /* Takes a vector of packets. */
3273 .vector_size = sizeof (u32),
3274 .n_errors = TCP_N_ERROR,
3275 .error_strings = tcp_error_strings,
3276 .n_next_nodes = TCP_LISTEN_N_NEXT,
3279 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3280 foreach_tcp_state_next
3283 .format_trace = format_tcp_rx_trace_short,
3288 VLIB_REGISTER_NODE (tcp6_listen_node) =
3290 .name = "tcp6-listen",
3291 /* Takes a vector of packets. */
3292 .vector_size = sizeof (u32),
3293 .n_errors = TCP_N_ERROR,
3294 .error_strings = tcp_error_strings,
3295 .n_next_nodes = TCP_LISTEN_N_NEXT,
3298 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3299 foreach_tcp_state_next
3302 .format_trace = format_tcp_rx_trace_short,
3306 typedef enum _tcp_input_next
3308 TCP_INPUT_NEXT_DROP,
3309 TCP_INPUT_NEXT_LISTEN,
3310 TCP_INPUT_NEXT_RCV_PROCESS,
3311 TCP_INPUT_NEXT_SYN_SENT,
3312 TCP_INPUT_NEXT_ESTABLISHED,
3313 TCP_INPUT_NEXT_RESET,
3314 TCP_INPUT_NEXT_PUNT,
3318 #define foreach_tcp4_input_next \
3319 _ (DROP, "ip4-drop") \
3320 _ (LISTEN, "tcp4-listen") \
3321 _ (RCV_PROCESS, "tcp4-rcv-process") \
3322 _ (SYN_SENT, "tcp4-syn-sent") \
3323 _ (ESTABLISHED, "tcp4-established") \
3324 _ (RESET, "tcp4-reset") \
3325 _ (PUNT, "ip4-punt")
3327 #define foreach_tcp6_input_next \
3328 _ (DROP, "ip6-drop") \
3329 _ (LISTEN, "tcp6-listen") \
3330 _ (RCV_PROCESS, "tcp6-rcv-process") \
3331 _ (SYN_SENT, "tcp6-syn-sent") \
3332 _ (ESTABLISHED, "tcp6-established") \
3333 _ (RESET, "tcp6-reset") \
3334 _ (PUNT, "ip6-punt")
3336 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3339 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3340 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3342 tcp_connection_t *tc;
3347 for (i = 0; i < n_bufs; i++)
3349 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3351 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3352 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3354 tcp = vlib_buffer_get_current (bs[i]);
3355 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3361 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3363 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3365 *next = TCP_INPUT_NEXT_DROP;
3367 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3369 *next = TCP_INPUT_NEXT_PUNT;
3370 *error = TCP_ERROR_PUNT;
3374 *next = TCP_INPUT_NEXT_RESET;
3375 *error = TCP_ERROR_NO_LISTENER;
3379 always_inline tcp_connection_t *
3380 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3381 u8 is_ip4, u8 is_nolookup)
3383 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3384 int n_advance_bytes, n_data_bytes;
3385 transport_connection_t *tc;
3391 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3392 int ip_hdr_bytes = ip4_header_bytes (ip4);
3393 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3395 *error = TCP_ERROR_LENGTH;
3398 tcp = ip4_next_header (ip4);
3399 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3400 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3401 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3403 /* Length check. Checksum computed by ipx_local no need to compute again */
3404 if (PREDICT_FALSE (n_data_bytes < 0))
3406 *error = TCP_ERROR_LENGTH;
3411 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3412 &ip4->src_address, tcp->dst_port,
3414 TRANSPORT_PROTO_TCP, thread_index,
3419 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3420 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3422 *error = TCP_ERROR_LENGTH;
3425 tcp = ip6_next_header (ip6);
3426 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3427 n_advance_bytes = tcp_header_bytes (tcp);
3428 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3430 n_advance_bytes += sizeof (ip6[0]);
3432 if (PREDICT_FALSE (n_data_bytes < 0))
3434 *error = TCP_ERROR_LENGTH;
3441 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3443 ip4_main_t *im = &ip4_main;
3444 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3445 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3448 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3450 tcp->dst_port, tcp->src_port,
3451 TRANSPORT_PROTO_TCP,
3452 thread_index, &result);
3458 (transport_connection_t *) tcp_connection_get (vnet_buffer (b)->
3459 tcp.connection_index,
3462 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3463 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3464 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3465 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3466 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3468 vnet_buffer (b)->tcp.flags = 0;
3470 *error = result ? TCP_ERROR_NONE + result : *error;
3472 return tcp_get_connection_from_transport (tc);
3476 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3477 vlib_buffer_t * b, u16 * next, u32 * error)
3482 tcp = tcp_buffer_hdr (b);
3483 flags = tcp->flags & filter_flags;
3484 *next = tm->dispatch_table[tc->state][flags].next;
3485 *error = tm->dispatch_table[tc->state][flags].error;
3488 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3489 || *next == TCP_INPUT_NEXT_RESET))
3491 /* Overload tcp flags to store state */
3492 tcp_state_t state = tc->state;
3493 vnet_buffer (b)->tcp.flags = tc->state;
3495 if (*error == TCP_ERROR_DISPATCH)
3496 clib_warning ("tcp conn %u disp error state %U flags %U",
3497 tc->c_c_index, format_tcp_state, state,
3498 format_tcp_flags, (int) flags);
3503 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3504 vlib_frame_t * frame, int is_ip4, u8 is_nolookup)
3506 u32 n_left_from, *from, thread_index = vm->thread_index;
3507 tcp_main_t *tm = vnet_get_tcp_main ();
3508 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3509 u16 nexts[VLIB_FRAME_SIZE], *next;
3511 tcp_set_time_now (tcp_get_worker (thread_index));
3513 from = vlib_frame_vector_args (frame);
3514 n_left_from = frame->n_vectors;
3515 vlib_get_buffers (vm, from, bufs, n_left_from);
3520 while (n_left_from >= 4)
3522 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3523 tcp_connection_t *tc0, *tc1;
3526 vlib_prefetch_buffer_header (b[2], STORE);
3527 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3529 vlib_prefetch_buffer_header (b[3], STORE);
3530 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3533 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3535 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3537 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4,
3540 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3542 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3543 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3545 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3546 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3548 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3549 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3553 if (PREDICT_TRUE (tc0 != 0))
3555 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3556 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3557 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3560 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3562 if (PREDICT_TRUE (tc1 != 0))
3564 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3565 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3566 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3569 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3576 while (n_left_from > 0)
3578 tcp_connection_t *tc0;
3579 u32 error0 = TCP_ERROR_NO_LISTENER;
3581 if (n_left_from > 1)
3583 vlib_prefetch_buffer_header (b[1], STORE);
3584 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3587 next[0] = TCP_INPUT_NEXT_DROP;
3588 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3590 if (PREDICT_TRUE (tc0 != 0))
3592 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3593 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3594 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3597 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3604 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3605 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3607 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3608 return frame->n_vectors;
3611 VLIB_NODE_FN (tcp4_input_nolookup_node) (vlib_main_t * vm,
3612 vlib_node_runtime_t * node,
3613 vlib_frame_t * from_frame)
3615 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3616 1 /* is_nolookup */ );
3619 VLIB_NODE_FN (tcp6_input_nolookup_node) (vlib_main_t * vm,
3620 vlib_node_runtime_t * node,
3621 vlib_frame_t * from_frame)
3623 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3624 1 /* is_nolookup */ );
3628 VLIB_REGISTER_NODE (tcp4_input_nolookup_node) =
3630 .name = "tcp4-input-nolookup",
3631 /* Takes a vector of packets. */
3632 .vector_size = sizeof (u32),
3633 .n_errors = TCP_N_ERROR,
3634 .error_strings = tcp_error_strings,
3635 .n_next_nodes = TCP_INPUT_N_NEXT,
3638 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3639 foreach_tcp4_input_next
3642 .format_buffer = format_tcp_header,
3643 .format_trace = format_tcp_rx_trace,
3648 VLIB_REGISTER_NODE (tcp6_input_nolookup_node) =
3650 .name = "tcp6-input-nolookup",
3651 /* Takes a vector of packets. */
3652 .vector_size = sizeof (u32),
3653 .n_errors = TCP_N_ERROR,
3654 .error_strings = tcp_error_strings,
3655 .n_next_nodes = TCP_INPUT_N_NEXT,
3658 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3659 foreach_tcp6_input_next
3662 .format_buffer = format_tcp_header,
3663 .format_trace = format_tcp_rx_trace,
3667 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3668 vlib_frame_t * from_frame)
3670 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3671 0 /* is_nolookup */ );
3674 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3675 vlib_frame_t * from_frame)
3677 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3678 0 /* is_nolookup */ );
3682 VLIB_REGISTER_NODE (tcp4_input_node) =
3684 .name = "tcp4-input",
3685 /* Takes a vector of packets. */
3686 .vector_size = sizeof (u32),
3687 .n_errors = TCP_N_ERROR,
3688 .error_strings = tcp_error_strings,
3689 .n_next_nodes = TCP_INPUT_N_NEXT,
3692 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3693 foreach_tcp4_input_next
3696 .format_buffer = format_tcp_header,
3697 .format_trace = format_tcp_rx_trace,
3702 VLIB_REGISTER_NODE (tcp6_input_node) =
3704 .name = "tcp6-input",
3705 /* Takes a vector of packets. */
3706 .vector_size = sizeof (u32),
3707 .n_errors = TCP_N_ERROR,
3708 .error_strings = tcp_error_strings,
3709 .n_next_nodes = TCP_INPUT_N_NEXT,
3712 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3713 foreach_tcp6_input_next
3716 .format_buffer = format_tcp_header,
3717 .format_trace = format_tcp_rx_trace,
3721 #ifndef CLIB_MARCH_VARIANT
3723 tcp_dispatch_table_init (tcp_main_t * tm)
3726 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3727 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3729 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3730 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3733 #define _(t,f,n,e) \
3735 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3736 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3739 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3740 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3741 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3742 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3743 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3744 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3745 TCP_ERROR_ACK_INVALID);
3746 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3747 TCP_ERROR_SEGMENT_INVALID);
3748 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3749 TCP_ERROR_SEGMENT_INVALID);
3750 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3751 TCP_ERROR_INVALID_CONNECTION);
3752 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3753 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3754 TCP_ERROR_SEGMENT_INVALID);
3755 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3756 TCP_ERROR_SEGMENT_INVALID);
3757 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3759 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3760 TCP_ERROR_SEGMENT_INVALID);
3761 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3762 TCP_ERROR_SEGMENT_INVALID);
3763 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3764 TCP_ERROR_SEGMENT_INVALID);
3765 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3766 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3767 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3768 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3769 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3770 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3772 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3773 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3775 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3777 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3778 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3779 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3780 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3782 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3784 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3785 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3786 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3788 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3789 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3790 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3791 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3792 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3793 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3794 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3795 /* SYN-ACK for a SYN */
3796 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3798 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3799 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3800 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3802 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3803 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3805 /* ACK for for established connection -> tcp-established. */
3806 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3807 /* FIN for for established connection -> tcp-established. */
3808 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3809 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3811 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3813 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3814 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3815 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3817 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3818 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3819 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3820 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3821 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3822 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3823 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3824 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3826 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3827 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3829 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3831 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3832 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3833 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3834 /* ACK or FIN-ACK to our FIN */
3835 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3836 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3838 /* FIN in reply to our FIN from the other side */
3839 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3840 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3841 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3843 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3844 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3845 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3846 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3847 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3848 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3849 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3851 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3852 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3853 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3854 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3856 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3858 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3859 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3860 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3861 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3863 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3864 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3865 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3866 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3868 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3870 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3871 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3872 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3873 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3875 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3876 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3878 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3880 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3881 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3882 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3884 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3885 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3886 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3887 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3888 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3889 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3890 /* FIN confirming that the peer (app) has closed */
3891 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3892 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3893 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3895 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3896 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3898 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3899 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3901 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3902 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3904 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3905 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3906 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3907 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3909 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3911 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3912 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3913 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3915 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3916 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3917 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3918 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3919 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3920 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3921 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3922 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3924 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3925 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3927 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3929 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3930 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3931 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3932 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3933 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3935 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3936 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3938 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3939 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3940 * incoming segment not containing a RST causes a RST to be sent in
3942 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3943 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3944 TCP_ERROR_CONNECTION_CLOSED);
3945 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3946 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3947 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3952 static clib_error_t *
3953 tcp_input_init (vlib_main_t * vm)
3955 clib_error_t *error = 0;
3956 tcp_main_t *tm = vnet_get_tcp_main ();
3958 if ((error = vlib_call_init_function (vm, tcp_init)))
3961 /* Initialize dispatch table. */
3962 tcp_dispatch_table_init (tm);
3967 VLIB_INIT_FUNCTION (tcp_input_init);
3969 #endif /* CLIB_MARCH_VARIANT */
3972 * fd.io coding-style-patch-verification: ON
3975 * eval: (c-set-style "gnu")