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/tcp/tcp_packet.h>
18 #include <vnet/tcp/tcp.h>
19 #include <vnet/session/session.h>
22 static char *tcp_error_strings[] = {
23 #define tcp_error(n,s) s,
24 #include <vnet/tcp/tcp_error.def>
28 /* All TCP nodes have the same outgoing arcs */
29 #define foreach_tcp_state_next \
30 _ (DROP4, "ip4-drop") \
31 _ (DROP6, "ip6-drop") \
32 _ (TCP4_OUTPUT, "tcp4-output") \
33 _ (TCP6_OUTPUT, "tcp6-output")
35 typedef enum _tcp_established_next
37 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
38 foreach_tcp_state_next
40 TCP_ESTABLISHED_N_NEXT,
41 } tcp_established_next_t;
43 typedef enum _tcp_rcv_process_next
45 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
46 foreach_tcp_state_next
48 TCP_RCV_PROCESS_N_NEXT,
49 } tcp_rcv_process_next_t;
51 typedef enum _tcp_syn_sent_next
53 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
54 foreach_tcp_state_next
57 } tcp_syn_sent_next_t;
59 typedef enum _tcp_listen_next
61 #define _(s,n) TCP_LISTEN_NEXT_##s,
62 foreach_tcp_state_next
67 /* Generic, state independent indices */
68 typedef enum _tcp_state_next
70 #define _(s,n) TCP_NEXT_##s,
71 foreach_tcp_state_next
76 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
77 : TCP_NEXT_TCP6_OUTPUT)
79 #define tcp_next_drop(is_ip4) (is_ip4 ? TCP_NEXT_DROP4 \
83 * Validate segment sequence number. As per RFC793:
85 * Segment Receive Test
87 * ------- ------- -------------------------------------------
88 * 0 0 SEG.SEQ = RCV.NXT
89 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
91 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
92 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
94 * This ultimately consists in checking if segment falls within the window.
95 * The one important difference compared to RFC793 is that we use rcv_las,
96 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
97 * peer's reference when computing our receive window.
100 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
101 * however, is too strict when we have retransmits. Instead we just check that
102 * the seq is not beyond the right edge and that the end of the segment is not
103 * less than the left edge.
105 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
106 * use rcv_nxt in the right edge window test instead of rcv_las.
110 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
112 return (seq_geq (end_seq, tc->rcv_las)
113 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
117 * Parse TCP header options.
119 * @param th TCP header
120 * @param to TCP options data structure to be populated
121 * @param is_syn set if packet is syn
122 * @return -1 if parsing failed
125 tcp_options_parse (tcp_header_t * th, tcp_options_t * to, u8 is_syn)
128 u8 opt_len, opts_len, kind;
132 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
133 data = (const u8 *) (th + 1);
135 /* Zero out all flags but those set in SYN */
136 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
137 | TCP_OPTS_FLAG_TSTAMP | TCP_OPTION_MSS);
139 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
143 /* Get options length */
144 if (kind == TCP_OPTION_EOL)
146 else if (kind == TCP_OPTION_NOOP)
158 /* weird option length */
159 if (opt_len < 2 || opt_len > opts_len)
169 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
171 to->flags |= TCP_OPTS_FLAG_MSS;
172 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
175 case TCP_OPTION_WINDOW_SCALE:
178 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
180 to->flags |= TCP_OPTS_FLAG_WSCALE;
181 to->wscale = data[2];
182 if (to->wscale > TCP_MAX_WND_SCALE)
183 to->wscale = TCP_MAX_WND_SCALE;
186 case TCP_OPTION_TIMESTAMP:
188 to->flags |= TCP_OPTS_FLAG_TSTAMP;
189 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
190 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
192 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
193 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
196 case TCP_OPTION_SACK_PERMITTED:
199 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
200 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
202 case TCP_OPTION_SACK_BLOCK:
203 /* If SACK permitted was not advertised or a SYN, break */
204 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
207 /* If too short or not correctly formatted, break */
208 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
211 to->flags |= TCP_OPTS_FLAG_SACK;
212 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
213 vec_reset_length (to->sacks);
214 for (j = 0; j < to->n_sack_blocks; j++)
216 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
217 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
218 vec_add1 (to->sacks, b);
222 /* Nothing to see here */
230 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
231 * timestamp to echo and it's less than tsval_recent, drop segment
232 * but still send an ACK in order to retain TCP's mechanism for detecting
233 * and recovering from half-open connections
235 * Or at least that's what the theory says. It seems that this might not work
236 * very well with packet reordering and fast retransmit. XXX
239 tcp_segment_check_paws (tcp_connection_t * tc)
241 return tcp_opts_tstamp (&tc->rcv_opts)
242 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
246 * Update tsval recent
249 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
252 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
253 * of an incoming segment:
254 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
255 * then the TSval from the segment is copied to TS.Recent;
256 * otherwise, the TSval is ignored.
258 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
259 && seq_leq (tc->rcv_las, seq_end))
261 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
262 tc->tsval_recent = tc->rcv_opts.tsval;
263 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
268 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
270 * It first verifies if segment has a wrapped sequence number (PAWS) and then
271 * does the processing associated to the first four steps (ignoring security
272 * and precedence): sequence number, rst bit and syn bit checks.
274 * @return 0 if segments passes validation.
277 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
278 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
280 /* We could get a burst of RSTs interleaved with acks */
281 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
283 tcp_send_reset (tc0);
284 *error0 = TCP_ERROR_CONNECTION_CLOSED;
288 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
290 *error0 = TCP_ERROR_SEGMENT_INVALID;
294 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
296 *error0 = TCP_ERROR_OPTIONS;
300 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
302 *error0 = TCP_ERROR_PAWS;
303 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
304 vnet_buffer (b0)->tcp.seq_end);
306 /* If it just so happens that a segment updates tsval_recent for a
307 * segment over 24 days old, invalidate tsval_recent. */
308 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
309 tcp_time_now_w_thread (tc0->c_thread_index)))
311 tc0->tsval_recent = tc0->rcv_opts.tsval;
312 clib_warning ("paws failed: 24-day old segment");
314 /* Drop after ack if not rst. Resets can fail paws check as per
315 * RFC 7323 sec. 5.2: When an <RST> segment is received, it MUST NOT
316 * be subjected to the PAWS check by verifying an acceptable value in
318 else if (!tcp_rst (th0))
320 tcp_program_ack (tc0);
321 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
326 /* 1st: check sequence number */
327 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
328 vnet_buffer (b0)->tcp.seq_end))
330 /* SYN/SYN-ACK retransmit */
332 && vnet_buffer (b0)->tcp.seq_number == tc0->rcv_nxt - 1)
334 tcp_options_parse (th0, &tc0->rcv_opts, 1);
335 if (tc0->state == TCP_STATE_SYN_RCVD)
337 tcp_send_synack (tc0);
338 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
339 *error0 = TCP_ERROR_SYNS_RCVD;
343 tcp_program_ack (tc0);
344 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
345 *error0 = TCP_ERROR_SYN_ACKS_RCVD;
350 /* If our window is 0 and the packet is in sequence, let it pass
351 * through for ack processing. It should be dropped later. */
352 if (tc0->rcv_wnd < tc0->snd_mss
353 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
356 /* If we entered recovery and peer did so as well, there's a chance that
357 * dup acks won't be acceptable on either end because seq_end may be less
358 * than rcv_las. This can happen if acks are lost in both directions. */
359 if (tcp_in_recovery (tc0)
360 && seq_geq (vnet_buffer (b0)->tcp.seq_number,
361 tc0->rcv_las - tc0->rcv_wnd)
362 && seq_leq (vnet_buffer (b0)->tcp.seq_end,
363 tc0->rcv_nxt + tc0->rcv_wnd))
366 *error0 = TCP_ERROR_RCV_WND;
368 tc0->errors.below_data_wnd += seq_lt (vnet_buffer (b0)->tcp.seq_end,
371 /* If not RST, send dup ack */
374 tcp_program_dupack (tc0);
375 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
383 /* 2nd: check the RST bit */
384 if (PREDICT_FALSE (tcp_rst (th0)))
386 tcp_connection_reset (tc0);
387 *error0 = TCP_ERROR_RST_RCVD;
391 /* 3rd: check security and precedence (skip) */
393 /* 4th: check the SYN bit (in window) */
394 if (PREDICT_FALSE (tcp_syn (th0)))
396 /* As per RFC5961 send challenge ack instead of reset */
397 tcp_program_ack (tc0);
398 *error0 = TCP_ERROR_SPURIOUS_SYN;
402 /* If segment in window, save timestamp */
403 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
404 vnet_buffer (b0)->tcp.seq_end);
412 tcp_rcv_ack_no_cc (tcp_connection_t * tc, vlib_buffer_t * b, u32 * error)
414 /* SND.UNA =< SEG.ACK =< SND.NXT */
415 if (!(seq_leq (tc->snd_una, vnet_buffer (b)->tcp.ack_number)
416 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
418 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
419 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
421 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
424 *error = TCP_ERROR_ACK_INVALID;
429 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
430 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
431 *error = TCP_ERROR_ACK_OK;
436 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
438 * Note that although the original article, srtt and rttvar are scaled
439 * to minimize round-off errors, here we don't. Instead, we rely on
440 * better precision time measurements.
442 * TODO support us rtt resolution
445 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
451 err = mrtt - tc->srtt;
453 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
454 * The increase should be bound */
455 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
456 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
457 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
461 /* First measurement. */
463 tc->rttvar = mrtt >> 1;
467 #ifndef CLIB_MARCH_VARIANT
469 tcp_update_rto (tcp_connection_t * tc)
471 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
472 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
474 #endif /* CLIB_MARCH_VARIANT */
477 * Update RTT estimate and RTO timer
479 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
480 * timing. Middle boxes are known to fiddle with TCP options so we
481 * should give higher priority to ACK timing.
483 * This should be called only if previously sent bytes have been acked.
485 * return 1 if valid rtt 0 otherwise
488 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
492 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
493 * RTT because they're ambiguous. */
494 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
496 if (tcp_in_recovery (tc))
501 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
503 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
504 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
505 mrtt = clib_max ((u32) (sample * THZ), 1);
506 /* Allow measuring of a new RTT */
509 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
510 * snd_una, i.e., the left side of the send window:
511 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
512 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
514 u32 now = tcp_tstamp (tc);
515 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
518 /* Ignore dubious measurements */
519 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
522 tcp_estimate_rtt (tc, mrtt);
526 /* If we got here something must've been ACKed so make sure boff is 0,
527 * even if mrtt is not valid since we update the rto lower */
535 tcp_estimate_initial_rtt (tcp_connection_t * tc)
537 u8 thread_index = vlib_num_workers ()? 1 : 0;
542 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
543 tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001);
544 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
549 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
550 mrtt = clib_max (mrtt, 1);
551 /* Due to retransmits we don't know the initial mrtt */
552 if (tc->rto_boff && mrtt > 1 * THZ)
554 tc->mrtt_us = (f64) mrtt *TCP_TICK;
557 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
558 tcp_estimate_rtt (tc, mrtt);
563 * Dequeue bytes for connections that have received acks in last burst
566 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
568 u32 thread_index = wrk->vm->thread_index;
569 u32 *pending_deq_acked;
570 tcp_connection_t *tc;
573 if (!vec_len (wrk->pending_deq_acked))
576 pending_deq_acked = wrk->pending_deq_acked;
577 for (i = 0; i < vec_len (pending_deq_acked); i++)
579 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
580 tc->flags &= ~TCP_CONN_DEQ_PENDING;
582 if (PREDICT_FALSE (!tc->burst_acked))
585 /* Dequeue the newly ACKed bytes */
586 session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
588 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
590 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
592 if (seq_leq (tc->psh_seq, tc->snd_una))
593 tc->flags &= ~TCP_CONN_PSH_PENDING;
596 /* If everything has been acked, stop retransmit timer
597 * otherwise update. */
598 tcp_retransmit_timer_update (tc);
600 /* If not congested, update pacer based on our new
602 if (!tcp_in_fastrecovery (tc))
603 tcp_connection_tx_pacer_update (tc);
605 _vec_len (wrk->pending_deq_acked) = 0;
609 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
611 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
613 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
614 tc->flags |= TCP_CONN_DEQ_PENDING;
616 tc->burst_acked += tc->bytes_acked + tc->sack_sb.snd_una_adv;
620 * Check if duplicate ack as per RFC5681 Sec. 2
623 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
626 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
627 && seq_gt (tc->snd_nxt, tc->snd_una)
628 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
629 && (prev_snd_wnd == tc->snd_wnd));
633 * Checks if ack is a congestion control event.
636 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
637 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
639 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
640 * defined to be 'duplicate' */
641 *is_dack = tc->sack_sb.last_sacked_bytes
642 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
644 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
647 #ifndef CLIB_MARCH_VARIANT
649 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
651 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
652 return hole - sb->holes;
656 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
658 return hole->end - hole->start;
661 sack_scoreboard_hole_t *
662 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
664 if (index != TCP_INVALID_SACK_HOLE_INDEX)
665 return pool_elt_at_index (sb->holes, index);
669 sack_scoreboard_hole_t *
670 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
672 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
673 return pool_elt_at_index (sb->holes, hole->next);
677 sack_scoreboard_hole_t *
678 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
680 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
681 return pool_elt_at_index (sb->holes, hole->prev);
685 sack_scoreboard_hole_t *
686 scoreboard_first_hole (sack_scoreboard_t * sb)
688 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
689 return pool_elt_at_index (sb->holes, sb->head);
693 sack_scoreboard_hole_t *
694 scoreboard_last_hole (sack_scoreboard_t * sb)
696 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
697 return pool_elt_at_index (sb->holes, sb->tail);
702 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
704 sack_scoreboard_hole_t *next, *prev;
706 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
708 next = pool_elt_at_index (sb->holes, hole->next);
709 next->prev = hole->prev;
713 sb->tail = hole->prev;
716 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
718 prev = pool_elt_at_index (sb->holes, hole->prev);
719 prev->next = hole->next;
723 sb->head = hole->next;
726 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
727 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
729 /* Poison the entry */
731 clib_memset (hole, 0xfe, sizeof (*hole));
733 pool_put (sb->holes, hole);
736 static sack_scoreboard_hole_t *
737 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
740 sack_scoreboard_hole_t *hole, *next, *prev;
743 pool_get (sb->holes, hole);
744 clib_memset (hole, 0, sizeof (*hole));
748 hole_index = scoreboard_hole_index (sb, hole);
750 prev = scoreboard_get_hole (sb, prev_index);
753 hole->prev = prev_index;
754 hole->next = prev->next;
756 if ((next = scoreboard_next_hole (sb, hole)))
757 next->prev = hole_index;
759 sb->tail = hole_index;
761 prev->next = hole_index;
765 sb->head = hole_index;
766 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
767 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
772 #endif /* CLIB_MARCH_VARIANT */
774 #ifndef CLIB_MARCH_VARIANT
776 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
778 sack_scoreboard_hole_t *left, *right;
779 u32 bytes = 0, blks = 0;
781 sb->last_lost_bytes = 0;
783 sb->sacked_bytes = 0;
784 left = scoreboard_last_hole (sb);
788 if (seq_gt (sb->high_sacked, left->end))
790 bytes = sb->high_sacked - left->end;
794 while ((right = left)
795 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
796 && blks < TCP_DUPACK_THRESHOLD
797 /* left not updated if above conditions fail */
798 && (left = scoreboard_prev_hole (sb, right)))
800 bytes += right->start - left->end;
804 /* left is first lost */
809 sb->lost_bytes += scoreboard_hole_bytes (right);
810 sb->last_lost_bytes += left->is_lost ? 0 : left->end - left->start;
812 left = scoreboard_prev_hole (sb, right);
814 bytes += right->start - left->end;
816 while ((right = left));
819 sb->sacked_bytes = bytes;
823 * Figure out the next hole to retransmit
825 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
827 sack_scoreboard_hole_t *
828 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
829 sack_scoreboard_hole_t * start,
830 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
832 sack_scoreboard_hole_t *hole = 0;
834 hole = start ? start : scoreboard_first_hole (sb);
835 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
836 hole = scoreboard_next_hole (sb, hole);
838 /* Nothing, return */
841 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
845 /* Rule (1): if higher than rxt, less than high_sacked and lost */
846 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
848 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
852 /* Rule (2): available unsent data */
855 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
858 /* Rule (3): if hole not lost */
859 else if (seq_lt (hole->start, sb->high_sacked))
862 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
864 /* Rule (4): if hole beyond high_sacked */
867 ASSERT (seq_geq (hole->start, sb->high_sacked));
870 /* HighRxt MUST NOT be updated */
875 if (hole && seq_lt (sb->high_rxt, hole->start))
876 sb->high_rxt = hole->start;
880 #endif /* CLIB_MARCH_VARIANT */
883 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
885 sack_scoreboard_hole_t *hole;
886 hole = scoreboard_first_hole (sb);
889 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
890 sb->cur_rxt_hole = sb->head;
892 sb->high_rxt = snd_una;
893 sb->rescue_rxt = snd_una - 1;
896 #ifndef CLIB_MARCH_VARIANT
898 scoreboard_init (sack_scoreboard_t * sb)
900 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
901 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
902 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
906 scoreboard_clear (sack_scoreboard_t * sb)
908 sack_scoreboard_hole_t *hole;
909 while ((hole = scoreboard_first_hole (sb)))
911 scoreboard_remove_hole (sb, hole);
913 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
914 ASSERT (pool_elts (sb->holes) == 0);
915 sb->sacked_bytes = 0;
916 sb->last_sacked_bytes = 0;
917 sb->last_bytes_delivered = 0;
922 sb->last_lost_bytes = 0;
923 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
925 #endif /* CLIB_MARCH_VARIANT */
928 * Test that scoreboard is sane after recovery
930 * Returns 1 if scoreboard is empty or if first hole beyond
934 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
936 sack_scoreboard_hole_t *hole;
937 hole = scoreboard_first_hole (&tc->sack_sb);
938 return (!hole || (seq_geq (hole->start, tc->snd_una)
939 && seq_lt (hole->end, tc->snd_nxt)));
942 #ifndef CLIB_MARCH_VARIANT
945 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
947 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
948 u32 blk_index = 0, old_sacked_bytes, hole_index;
949 sack_scoreboard_t *sb = &tc->sack_sb;
950 sack_block_t *blk, tmp;
953 sb->last_sacked_bytes = 0;
954 sb->last_bytes_delivered = 0;
957 if (!tcp_opts_sack (&tc->rcv_opts)
958 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
961 old_sacked_bytes = sb->sacked_bytes;
963 /* Remove invalid blocks */
964 blk = tc->rcv_opts.sacks;
965 while (blk < vec_end (tc->rcv_opts.sacks))
967 if (seq_lt (blk->start, blk->end)
968 && seq_gt (blk->start, tc->snd_una)
969 && seq_gt (blk->start, ack)
970 && seq_lt (blk->start, tc->snd_nxt)
971 && seq_leq (blk->end, tc->snd_nxt))
976 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
979 /* Add block for cumulative ack */
980 if (seq_gt (ack, tc->snd_una))
982 tmp.start = tc->snd_una;
984 vec_add1 (tc->rcv_opts.sacks, tmp);
987 if (vec_len (tc->rcv_opts.sacks) == 0)
990 tcp_scoreboard_trace_add (tc, ack);
992 /* Make sure blocks are ordered */
993 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
994 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
995 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
997 tmp = tc->rcv_opts.sacks[i];
998 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
999 tc->rcv_opts.sacks[j] = tmp;
1002 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1004 /* If no holes, insert the first that covers all outstanding bytes */
1005 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1006 tc->snd_una, tc->snd_nxt);
1007 sb->tail = scoreboard_hole_index (sb, last_hole);
1008 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
1009 sb->high_sacked = tmp.end;
1013 /* If we have holes but snd_una_max is beyond the last hole, update
1015 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
1016 last_hole = scoreboard_last_hole (sb);
1017 if (seq_gt (tc->snd_nxt, last_hole->end))
1019 if (seq_geq (last_hole->start, sb->high_sacked))
1021 last_hole->end = tc->snd_nxt;
1023 /* New hole after high sacked block */
1024 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1026 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1030 /* Keep track of max byte sacked for when the last hole
1032 if (seq_gt (tmp.end, sb->high_sacked))
1033 sb->high_sacked = tmp.end;
1036 /* Walk the holes with the SACK blocks */
1037 hole = pool_elt_at_index (sb->holes, sb->head);
1038 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
1040 blk = &tc->rcv_opts.sacks[blk_index];
1041 if (seq_leq (blk->start, hole->start))
1043 /* Block covers hole. Remove hole */
1044 if (seq_geq (blk->end, hole->end))
1046 next_hole = scoreboard_next_hole (sb, hole);
1048 /* Byte accounting: snd_una needs to be advanced */
1049 if (blk->end == ack)
1053 if (seq_lt (ack, next_hole->start))
1054 sb->snd_una_adv = next_hole->start - ack;
1055 sb->last_bytes_delivered +=
1056 next_hole->start - hole->end;
1060 ASSERT (seq_geq (sb->high_sacked, ack));
1061 sb->snd_una_adv = sb->high_sacked - ack;
1062 sb->last_bytes_delivered += sb->high_sacked - hole->end;
1065 scoreboard_remove_hole (sb, hole);
1068 /* Partial 'head' overlap */
1071 if (seq_gt (blk->end, hole->start))
1073 hole->start = blk->end;
1080 /* Hole must be split */
1081 if (seq_lt (blk->end, hole->end))
1083 hole_index = scoreboard_hole_index (sb, hole);
1084 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1087 /* Pool might've moved */
1088 hole = scoreboard_get_hole (sb, hole_index);
1089 hole->end = blk->start;
1091 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1093 else if (seq_lt (blk->start, hole->end))
1095 hole->end = blk->start;
1097 hole = scoreboard_next_hole (sb, hole);
1101 if (pool_elts (sb->holes) == 1)
1103 hole = scoreboard_first_hole (sb);
1104 if (hole->start == ack + sb->snd_una_adv && hole->end == tc->snd_nxt)
1105 scoreboard_remove_hole (sb, hole);
1108 scoreboard_update_bytes (tc, sb);
1109 sb->last_sacked_bytes = sb->sacked_bytes
1110 - (old_sacked_bytes - sb->last_bytes_delivered);
1112 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1113 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1114 || sb->sacked_bytes < tc->snd_nxt - seq_max (tc->snd_una, ack));
1115 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1116 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1117 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1118 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1119 ASSERT (sb->last_lost_bytes <= sb->lost_bytes);
1121 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1123 #endif /* CLIB_MARCH_VARIANT */
1126 * Try to update snd_wnd based on feedback received from peer.
1128 * If successful, and new window is 'effectively' 0, activate persist
1132 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1134 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1135 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1136 if (seq_lt (tc->snd_wl1, seq)
1137 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1139 tc->snd_wnd = snd_wnd;
1142 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1144 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1146 /* Set persist timer if not set and we just got 0 wnd */
1147 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1148 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1149 tcp_persist_timer_set (tc);
1153 tcp_persist_timer_reset (tc);
1154 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1157 tcp_update_rto (tc);
1163 #ifndef CLIB_MARCH_VARIANT
1165 * Init loss recovery/fast recovery.
1167 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1168 * updated in @ref tcp_cc_handle_event after fast retransmit
1171 tcp_cc_init_congestion (tcp_connection_t * tc)
1173 tcp_fastrecovery_on (tc);
1174 tc->snd_congestion = tc->snd_nxt;
1175 tc->cwnd_acc_bytes = 0;
1176 tc->snd_rxt_bytes = 0;
1177 tc->prev_ssthresh = tc->ssthresh;
1178 tc->prev_cwnd = tc->cwnd;
1179 tc->cc_algo->congestion (tc);
1180 tc->fr_occurences += 1;
1181 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1183 #endif /* CLIB_MARCH_VARIANT */
1186 tcp_cc_recovery_exit (tcp_connection_t * tc)
1189 tcp_update_rto (tc);
1192 tcp_recovery_off (tc);
1193 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1196 #ifndef CLIB_MARCH_VARIANT
1198 tcp_cc_fastrecovery_clear (tcp_connection_t * tc)
1200 tc->snd_rxt_bytes = 0;
1201 tc->rcv_dupacks = 0;
1204 tcp_fastrecovery_off (tc);
1205 tcp_fastrecovery_first_off (tc);
1206 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1208 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1210 #endif /* CLIB_MARCH_VARIANT */
1213 tcp_cc_congestion_undo (tcp_connection_t * tc)
1215 tc->cwnd = tc->prev_cwnd;
1216 tc->ssthresh = tc->prev_ssthresh;
1217 tc->rcv_dupacks = 0;
1218 if (tcp_in_recovery (tc))
1220 tcp_cc_recovery_exit (tc);
1221 tc->snd_nxt = seq_max (tc->snd_nxt, tc->snd_congestion);
1223 else if (tcp_in_fastrecovery (tc))
1225 tcp_cc_fastrecovery_clear (tc);
1227 tcp_cc_undo_recovery (tc);
1228 ASSERT (tc->rto_boff == 0);
1229 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1233 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1235 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1237 && tcp_opts_tstamp (&tc->rcv_opts)
1238 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1242 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1244 return (tcp_in_fastrecovery (tc)
1245 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1249 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1251 return (tcp_cc_is_spurious_timeout_rxt (tc)
1252 || tcp_cc_is_spurious_fast_rxt (tc));
1256 tcp_cc_recover (tcp_connection_t * tc)
1258 ASSERT (tcp_in_cong_recovery (tc));
1259 if (tcp_cc_is_spurious_retransmit (tc))
1261 tcp_cc_congestion_undo (tc);
1265 if (tcp_in_recovery (tc))
1266 tcp_cc_recovery_exit (tc);
1267 else if (tcp_in_fastrecovery (tc))
1269 tcp_cc_recovered (tc);
1270 tcp_cc_fastrecovery_clear (tc);
1273 ASSERT (tc->rto_boff == 0);
1274 ASSERT (!tcp_in_cong_recovery (tc));
1275 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1280 tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1282 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1284 /* Congestion avoidance */
1285 tcp_cc_rcv_ack (tc, rs);
1287 /* If a cumulative ack, make sure dupacks is 0 */
1288 tc->rcv_dupacks = 0;
1290 /* When dupacks hits the threshold we only enter fast retransmit if
1291 * cumulative ack covers more than snd_congestion. Should snd_una
1292 * wrap this test may fail under otherwise valid circumstances.
1293 * Therefore, proactively update snd_congestion when wrap detected. */
1295 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1296 && seq_gt (tc->snd_congestion, tc->snd_una)))
1297 tc->snd_congestion = tc->snd_una - 1;
1301 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1303 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1307 tcp_should_fastrecover (tcp_connection_t * tc)
1309 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1310 || tcp_should_fastrecover_sack (tc));
1314 * One function to rule them all ... and in the darkness bind them
1317 tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs,
1322 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1324 if (tc->bytes_acked)
1326 tcp_program_fastretransmit (tc);
1330 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1331 * it account for the bytes that left the network.
1333 else if (is_dack && !tcp_in_recovery (tc))
1335 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1336 ASSERT (tc->snd_una != tc->snd_nxt || tc->sack_sb.last_sacked_bytes);
1340 /* Pure duplicate ack. If some data got acked, it's handled lower */
1341 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1343 ASSERT (tcp_in_fastrecovery (tc));
1344 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1347 else if (tcp_should_fastrecover (tc))
1351 ASSERT (!tcp_in_fastrecovery (tc));
1353 /* Heuristic to catch potential late dupacks
1354 * after fast retransmit exits */
1355 if (is_dack && tc->snd_una == tc->snd_congestion
1356 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1358 tc->rcv_dupacks = 0;
1362 tcp_cc_init_congestion (tc);
1363 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1365 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1367 tc->cwnd = tc->ssthresh;
1368 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1372 /* Post retransmit update cwnd to ssthresh and account for the
1373 * three segments that have left the network and should've been
1374 * buffered at the receiver XXX */
1375 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1378 /* Constrain rate until we get a partial ack */
1379 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1380 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1381 0 /* start bucket */ );
1382 tcp_program_fastretransmit (tc);
1385 else if (!tc->bytes_acked
1386 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1388 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1394 /* Don't allow entry in fast recovery if still in recovery, for now */
1395 else if (0 && is_dack && tcp_in_recovery (tc))
1397 /* If of of the two conditions lower hold, reset dupacks because
1398 * we're probably after timeout (RFC6582 heuristics).
1399 * If Cumulative ack does not cover more than congestion threshold,
1401 * 1) The following doesn't hold: The congestion window is greater
1402 * than SMSS bytes and the difference between highest_ack
1403 * and prev_highest_ack is at most 4*SMSS bytes
1404 * 2) Echoed timestamp in the last non-dup ack does not equal the
1407 if (seq_leq (tc->snd_una, tc->snd_congestion)
1408 && ((!(tc->cwnd > tc->snd_mss
1409 && tc->bytes_acked <= 4 * tc->snd_mss))
1410 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1412 tc->rcv_dupacks = 0;
1417 if (!tc->bytes_acked)
1421 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1424 * Legitimate ACK. 1) See if we can exit recovery
1427 /* Update the pacing rate. For the first partial ack we move from
1428 * the artificially constrained rate to the one after congestion */
1429 tcp_connection_tx_pacer_update (tc);
1431 if (seq_geq (tc->snd_una, tc->snd_congestion))
1433 tcp_retransmit_timer_update (tc);
1435 /* If spurious return, we've already updated everything */
1436 if (tcp_cc_recover (tc))
1438 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1442 /* Treat as congestion avoidance ack */
1443 tcp_cc_rcv_ack (tc, rs);
1448 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1451 /* XXX limit this only to first partial ack? */
1452 tcp_retransmit_timer_update (tc);
1454 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1455 * reset dupacks to 0. Also needed if in congestion recovery */
1456 tc->rcv_dupacks = 0;
1458 /* Post RTO timeout don't try anything fancy */
1459 if (tcp_in_recovery (tc))
1461 tcp_cc_rcv_ack (tc, rs);
1462 transport_add_tx_event (&tc->connection);
1466 /* Remove retransmitted bytes that have been delivered */
1467 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1469 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1470 >= tc->sack_sb.last_bytes_delivered
1471 || (tc->flags & TCP_CONN_FINSNT));
1473 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1474 * remove sacked bytes delivered */
1475 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1477 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1478 - tc->sack_sb.last_bytes_delivered;
1479 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1480 tc->snd_rxt_bytes -= rxt_delivered;
1484 /* Apparently all retransmitted holes have been acked */
1485 tc->snd_rxt_bytes = 0;
1486 tc->sack_sb.high_rxt = tc->snd_una;
1491 tcp_fastrecovery_first_on (tc);
1492 if (tc->snd_rxt_bytes > tc->bytes_acked)
1493 tc->snd_rxt_bytes -= tc->bytes_acked;
1495 tc->snd_rxt_bytes = 0;
1498 tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs);
1501 * Since this was a partial ack, try to retransmit some more data
1503 tcp_program_fastretransmit (tc);
1507 * Process incoming ACK
1510 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1511 tcp_header_t * th, u32 * error)
1513 u32 prev_snd_wnd, prev_snd_una;
1514 tcp_rate_sample_t rs = { 0 };
1517 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1519 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1520 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1522 /* We've probably entered recovery and the peer still has some
1523 * of the data we've sent. Update snd_nxt and accept the ack */
1524 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1525 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1527 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1531 tc->errors.above_ack_wnd += 1;
1532 *error = TCP_ERROR_ACK_FUTURE;
1533 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1534 vnet_buffer (b)->tcp.ack_number);
1538 /* If old ACK, probably it's an old dupack */
1539 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1541 tc->errors.below_ack_wnd += 1;
1542 *error = TCP_ERROR_ACK_OLD;
1543 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1544 vnet_buffer (b)->tcp.ack_number);
1545 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1546 tcp_cc_handle_event (tc, 0, 1);
1547 /* Don't drop yet */
1554 * Looks okay, process feedback
1557 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1558 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1560 prev_snd_wnd = tc->snd_wnd;
1561 prev_snd_una = tc->snd_una;
1562 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1563 vnet_buffer (b)->tcp.ack_number,
1564 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1565 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1566 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1567 tcp_validate_txf_size (tc, tc->bytes_acked);
1569 if (tc->bytes_acked)
1571 tcp_program_dequeue (wrk, tc);
1572 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1575 if (tc->flags & TCP_CONN_RATE_SAMPLE)
1576 tcp_bt_sample_delivery_rate (tc, &rs);
1578 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1581 * Check if we have congestion event
1584 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1586 tcp_cc_handle_event (tc, &rs, is_dack);
1587 tc->dupacks_in += is_dack;
1588 if (!tcp_in_cong_recovery (tc))
1590 *error = TCP_ERROR_ACK_OK;
1593 *error = TCP_ERROR_ACK_DUP;
1594 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1600 * Update congestion control (slow start/congestion avoidance)
1602 tcp_cc_update (tc, &rs);
1603 *error = TCP_ERROR_ACK_OK;
1608 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1610 if (!tcp_disconnect_pending (tc))
1612 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1613 tcp_disconnect_pending_on (tc);
1618 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1620 u32 thread_index, *pending_disconnects;
1621 tcp_connection_t *tc;
1624 if (!vec_len (wrk->pending_disconnects))
1627 thread_index = wrk->vm->thread_index;
1628 pending_disconnects = wrk->pending_disconnects;
1629 for (i = 0; i < vec_len (pending_disconnects); i++)
1631 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1632 tcp_disconnect_pending_off (tc);
1633 session_transport_closing_notify (&tc->connection);
1635 _vec_len (wrk->pending_disconnects) = 0;
1639 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1642 /* Reject out-of-order fins */
1643 if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt)
1646 /* Account for the FIN and send ack */
1648 tcp_program_ack (tc);
1649 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1650 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1651 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1652 tcp_program_disconnect (wrk, tc);
1653 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
1654 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1655 *error = TCP_ERROR_FIN_RCVD;
1658 #ifndef CLIB_MARCH_VARIANT
1660 tcp_sack_vector_is_sane (sack_block_t * sacks)
1663 for (i = 1; i < vec_len (sacks); i++)
1665 if (sacks[i - 1].end == sacks[i].start)
1672 * Build SACK list as per RFC2018.
1674 * Makes sure the first block contains the segment that generated the current
1675 * ACK and the following ones are the ones most recently reported in SACK
1678 * @param tc TCP connection for which the SACK list is updated
1679 * @param start Start sequence number of the newest SACK block
1680 * @param end End sequence of the newest SACK block
1683 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1685 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1688 /* If the first segment is ooo add it to the list. Last write might've moved
1689 * rcv_nxt over the first segment. */
1690 if (seq_lt (tc->rcv_nxt, start))
1692 vec_add2 (new_list, block, 1);
1693 block->start = start;
1697 /* Find the blocks still worth keeping. */
1698 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1700 /* Discard if rcv_nxt advanced beyond current block */
1701 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1704 /* Merge or drop if segment overlapped by the new segment */
1705 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1706 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1708 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1709 new_list[0].start = tc->snd_sacks[i].start;
1710 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1711 new_list[0].end = tc->snd_sacks[i].end;
1715 /* Save to new SACK list if we have space. */
1716 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1717 vec_add1 (new_list, tc->snd_sacks[i]);
1720 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1722 /* Replace old vector with new one */
1723 vec_reset_length (tc->snd_sacks);
1724 tc->snd_sacks_fl = tc->snd_sacks;
1725 tc->snd_sacks = new_list;
1727 /* Segments should not 'touch' */
1728 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1732 tcp_sack_list_bytes (tcp_connection_t * tc)
1735 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1736 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1739 #endif /* CLIB_MARCH_VARIANT */
1741 /** Enqueue data for delivery to application */
1743 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1746 int written, error = TCP_ERROR_ENQUEUED;
1748 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1750 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1751 1 /* queue event */ , 1);
1752 tc->bytes_in += written;
1754 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1756 /* Update rcv_nxt */
1757 if (PREDICT_TRUE (written == data_len))
1759 tc->rcv_nxt += written;
1761 /* If more data written than expected, account for out-of-order bytes. */
1762 else if (written > data_len)
1764 tc->rcv_nxt += written;
1765 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1767 else if (written > 0)
1769 /* We've written something but FIFO is probably full now */
1770 tc->rcv_nxt += written;
1771 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1775 return TCP_ERROR_FIFO_FULL;
1778 /* Update SACK list if need be */
1779 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1781 /* Remove SACK blocks that have been delivered */
1782 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1788 /** Enqueue out-of-order data */
1790 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1796 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1799 /* Enqueue out-of-order data with relative offset */
1800 rv = session_enqueue_stream_connection (&tc->connection, b,
1801 vnet_buffer (b)->tcp.seq_number -
1802 tc->rcv_nxt, 0 /* queue event */ ,
1805 /* Nothing written */
1808 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1809 return TCP_ERROR_FIFO_FULL;
1812 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1813 tc->bytes_in += data_len;
1815 /* Update SACK list if in use */
1816 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1818 ooo_segment_t *newest;
1821 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1823 /* Get the newest segment from the fifo */
1824 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1827 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1828 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1829 start = tc->rcv_nxt + offset;
1830 end = start + ooo_segment_length (s0->rx_fifo, newest);
1831 tcp_update_sack_list (tc, start, end);
1832 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1833 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1837 return TCP_ERROR_ENQUEUED_OOO;
1841 * Check if ACK could be delayed. If ack can be delayed, it should return
1842 * true for a full frame. If we're always acking return 0.
1845 tcp_can_delack (tcp_connection_t * tc)
1847 /* Send ack if ... */
1849 /* just sent a rcv wnd 0
1850 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1851 /* constrained to send ack */
1852 || (tc->flags & TCP_CONN_SNDACK) != 0
1853 /* we're almost out of tx wnd */
1854 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1861 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1863 u32 discard, first = b->current_length;
1864 vlib_main_t *vm = vlib_get_main ();
1866 /* Handle multi-buffer segments */
1867 if (n_bytes_to_drop > b->current_length)
1869 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1873 discard = clib_min (n_bytes_to_drop, b->current_length);
1874 vlib_buffer_advance (b, discard);
1875 b = vlib_get_buffer (vm, b->next_buffer);
1876 n_bytes_to_drop -= discard;
1878 while (n_bytes_to_drop);
1879 if (n_bytes_to_drop > first)
1880 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1883 vlib_buffer_advance (b, n_bytes_to_drop);
1884 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1889 * Receive buffer for connection and handle acks
1891 * It handles both in order or out-of-order data.
1894 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1897 u32 error, n_bytes_to_drop, n_data_bytes;
1899 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1900 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1901 ASSERT (n_data_bytes);
1902 tc->data_segs_in += 1;
1904 /* Handle out-of-order data */
1905 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1907 /* Old sequence numbers allowed through because they overlapped
1909 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1911 /* Completely in the past (possible retransmit). Ack
1912 * retransmissions since we may not have any data to send */
1913 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1915 tcp_program_ack (tc);
1916 error = TCP_ERROR_SEGMENT_OLD;
1920 /* Chop off the bytes in the past and see if what is left
1921 * can be enqueued in order */
1922 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1923 n_data_bytes -= n_bytes_to_drop;
1924 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1925 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1927 error = TCP_ERROR_SEGMENT_OLD;
1933 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1934 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1935 tcp_program_dupack (tc);
1936 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1937 tc->errors.above_data_wnd += seq_gt (vnet_buffer (b)->tcp.seq_end,
1938 tc->rcv_las + tc->rcv_wnd);
1944 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1945 * segments can be enqueued after fifo tail offset changes. */
1946 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1947 if (tcp_can_delack (tc))
1949 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1950 tcp_timer_set (tc, TCP_TIMER_DELACK, tcp_cfg.delack_time);
1954 tcp_program_ack (tc);
1962 tcp_header_t tcp_header;
1963 tcp_connection_t tcp_connection;
1967 format_tcp_rx_trace (u8 * s, va_list * args)
1969 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1970 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1971 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1972 u32 indent = format_get_indent (s);
1974 s = format (s, "%U\n%U%U",
1975 format_tcp_header, &t->tcp_header, 128,
1976 format_white_space, indent,
1977 format_tcp_connection, &t->tcp_connection, 1);
1983 format_tcp_rx_trace_short (u8 * s, va_list * args)
1985 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1986 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1987 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1989 s = format (s, "%d -> %d (%U)",
1990 clib_net_to_host_u16 (t->tcp_header.dst_port),
1991 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1992 t->tcp_connection.state);
1998 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1999 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2003 clib_memcpy_fast (&t0->tcp_connection, tc0,
2004 sizeof (t0->tcp_connection));
2008 th0 = tcp_buffer_hdr (b0);
2010 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2014 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2015 vlib_frame_t * frame, u8 is_ip4)
2019 n_left = frame->n_vectors;
2020 from = vlib_frame_vector_args (frame);
2024 tcp_connection_t *tc0;
2031 b0 = vlib_get_buffer (vm, bi0);
2033 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2035 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2036 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2038 th0 = tcp_buffer_hdr (b0);
2039 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2048 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2049 u8 is_ip4, u32 evt, u32 val)
2052 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2054 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2057 #define tcp_maybe_inc_counter(node_id, err, count) \
2059 if (next0 != tcp_next_drop (is_ip4)) \
2060 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2061 tcp6_##node_id##_node.index, is_ip4, err, \
2064 #define tcp_inc_counter(node_id, err, count) \
2065 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2066 tcp6_##node_id##_node.index, is_ip4, \
2068 #define tcp_maybe_inc_err_counter(cnts, err) \
2070 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2072 #define tcp_inc_err_counter(cnts, err, val) \
2076 #define tcp_store_err_counters(node_id, cnts) \
2079 for (i = 0; i < TCP_N_ERROR; i++) \
2081 tcp_inc_counter(node_id, i, cnts[i]); \
2086 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2087 vlib_frame_t * frame, int is_ip4)
2089 u32 thread_index = vm->thread_index, errors = 0;
2090 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2091 u32 n_left_from, *from, *first_buffer;
2092 u16 err_counters[TCP_N_ERROR] = { 0 };
2094 if (node->flags & VLIB_NODE_FLAG_TRACE)
2095 tcp_established_trace_frame (vm, node, frame, is_ip4);
2097 first_buffer = from = vlib_frame_vector_args (frame);
2098 n_left_from = frame->n_vectors;
2100 while (n_left_from > 0)
2102 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2105 tcp_connection_t *tc0;
2107 if (n_left_from > 1)
2110 pb = vlib_get_buffer (vm, from[1]);
2111 vlib_prefetch_buffer_header (pb, LOAD);
2112 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2119 b0 = vlib_get_buffer (vm, bi0);
2120 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2123 if (PREDICT_FALSE (tc0 == 0))
2125 error0 = TCP_ERROR_INVALID_CONNECTION;
2129 th0 = tcp_buffer_hdr (b0);
2131 /* TODO header prediction fast path */
2133 /* 1-4: check SEQ, RST, SYN */
2134 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2136 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2140 /* 5: check the ACK field */
2141 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2144 /* 6: check the URG bit TODO */
2146 /* 7: process the segment text */
2147 if (vnet_buffer (b0)->tcp.data_len)
2148 error0 = tcp_segment_rcv (wrk, tc0, b0);
2150 /* 8: check the FIN bit */
2151 if (PREDICT_FALSE (tcp_is_fin (th0)))
2152 tcp_rcv_fin (wrk, tc0, b0, &error0);
2155 tcp_inc_err_counter (err_counters, error0, 1);
2158 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2160 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2161 tcp_store_err_counters (established, err_counters);
2162 tcp_handle_postponed_dequeues (wrk);
2163 tcp_handle_disconnects (wrk);
2164 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2166 return frame->n_vectors;
2169 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2170 vlib_node_runtime_t * node,
2171 vlib_frame_t * from_frame)
2173 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2176 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2177 vlib_node_runtime_t * node,
2178 vlib_frame_t * from_frame)
2180 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2184 VLIB_REGISTER_NODE (tcp4_established_node) =
2186 .name = "tcp4-established",
2187 /* Takes a vector of packets. */
2188 .vector_size = sizeof (u32),
2189 .n_errors = TCP_N_ERROR,
2190 .error_strings = tcp_error_strings,
2191 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2194 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2195 foreach_tcp_state_next
2198 .format_trace = format_tcp_rx_trace_short,
2203 VLIB_REGISTER_NODE (tcp6_established_node) =
2205 .name = "tcp6-established",
2206 /* Takes a vector of packets. */
2207 .vector_size = sizeof (u32),
2208 .n_errors = TCP_N_ERROR,
2209 .error_strings = tcp_error_strings,
2210 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2213 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2214 foreach_tcp_state_next
2217 .format_trace = format_tcp_rx_trace_short,
2223 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2225 transport_connection_t *tmp = 0;
2232 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2235 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2236 && (tc->state == TCP_STATE_LISTEN
2237 || tc->c_rmt_port == hdr->src_port));
2241 handle = session_lookup_half_open_handle (&tc->connection);
2242 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2243 tc->c_proto, tc->c_is_ip4);
2247 if (tmp->lcl_port == hdr->dst_port
2248 && tmp->rmt_port == hdr->src_port)
2250 TCP_DBG ("half-open is valid!");
2258 * Lookup transport connection
2260 static tcp_connection_t *
2261 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2265 transport_connection_t *tconn;
2266 tcp_connection_t *tc;
2271 ip4 = vlib_buffer_get_current (b);
2272 tcp = ip4_next_header (ip4);
2273 tconn = session_lookup_connection_wt4 (fib_index,
2278 TRANSPORT_PROTO_TCP,
2279 thread_index, &is_filtered);
2280 tc = tcp_get_connection_from_transport (tconn);
2281 ASSERT (tcp_lookup_is_valid (tc, tcp));
2286 ip6 = vlib_buffer_get_current (b);
2287 tcp = ip6_next_header (ip6);
2288 tconn = session_lookup_connection_wt6 (fib_index,
2293 TRANSPORT_PROTO_TCP,
2294 thread_index, &is_filtered);
2295 tc = tcp_get_connection_from_transport (tconn);
2296 ASSERT (tcp_lookup_is_valid (tc, tcp));
2302 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2303 vlib_frame_t * from_frame, int is_ip4)
2305 u32 n_left_from, *from, *first_buffer, errors = 0;
2306 u32 my_thread_index = vm->thread_index;
2307 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2309 from = first_buffer = vlib_frame_vector_args (from_frame);
2310 n_left_from = from_frame->n_vectors;
2312 while (n_left_from > 0)
2314 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2315 tcp_connection_t *tc0, *new_tc0;
2316 tcp_header_t *tcp0 = 0;
2324 b0 = vlib_get_buffer (vm, bi0);
2326 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2327 if (PREDICT_FALSE (tc0 == 0))
2329 error0 = TCP_ERROR_INVALID_CONNECTION;
2333 /* Half-open completed recently but the connection was't removed
2334 * yet by the owning thread */
2335 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2337 /* Make sure the connection actually exists */
2338 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2339 my_thread_index, is_ip4));
2340 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2344 ack0 = vnet_buffer (b0)->tcp.ack_number;
2345 seq0 = vnet_buffer (b0)->tcp.seq_number;
2346 tcp0 = tcp_buffer_hdr (b0);
2348 /* Crude check to see if the connection handle does not match
2349 * the packet. Probably connection just switched to established */
2350 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2351 || tcp0->src_port != tc0->c_rmt_port))
2353 error0 = TCP_ERROR_INVALID_CONNECTION;
2357 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2358 && !tcp_syn (tcp0)))
2360 error0 = TCP_ERROR_SEGMENT_INVALID;
2364 /* SYNs consume sequence numbers */
2365 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2368 * 1. check the ACK bit
2372 * If the ACK bit is set
2373 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2374 * the RST bit is set, if so drop the segment and return)
2375 * <SEQ=SEG.ACK><CTL=RST>
2376 * and discard the segment. Return.
2377 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2381 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2383 if (!tcp_rst (tcp0))
2384 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2385 error0 = TCP_ERROR_RCV_WND;
2389 /* Make sure ACK is valid */
2390 if (seq_gt (tc0->snd_una, ack0))
2392 error0 = TCP_ERROR_ACK_INVALID;
2398 * 2. check the RST bit
2403 /* If ACK is acceptable, signal client that peer is not
2404 * willing to accept connection and drop connection*/
2406 tcp_connection_reset (tc0);
2407 error0 = TCP_ERROR_RST_RCVD;
2412 * 3. check the security and precedence (skipped)
2416 * 4. check the SYN bit
2419 /* No SYN flag. Drop. */
2420 if (!tcp_syn (tcp0))
2422 error0 = TCP_ERROR_SEGMENT_INVALID;
2427 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2429 error0 = TCP_ERROR_OPTIONS;
2433 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2434 * current thread pool. */
2435 new_tc0 = tcp_connection_alloc_w_base (my_thread_index, tc0);
2436 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2437 new_tc0->irs = seq0;
2438 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2439 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2441 /* If this is not the owning thread, wait for syn retransmit to
2442 * expire and cleanup then */
2443 if (tcp_half_open_connection_cleanup (tc0))
2444 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2446 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2448 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2449 new_tc0->tsval_recent_age = tcp_time_now ();
2452 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2453 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2455 new_tc0->rcv_wscale = 0;
2457 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2458 << new_tc0->snd_wscale;
2459 new_tc0->snd_wl1 = seq0;
2460 new_tc0->snd_wl2 = ack0;
2462 tcp_connection_init_vars (new_tc0);
2464 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2465 if (PREDICT_TRUE (tcp_ack (tcp0)))
2467 /* Our SYN is ACKed: we have iss < ack = snd_una */
2469 /* TODO Dequeue acknowledged segments if we support Fast Open */
2470 new_tc0->snd_una = ack0;
2471 new_tc0->state = TCP_STATE_ESTABLISHED;
2473 /* Make sure las is initialized for the wnd computation */
2474 new_tc0->rcv_las = new_tc0->rcv_nxt;
2476 /* Notify app that we have connection. If session layer can't
2477 * allocate session send reset */
2478 if (session_stream_connect_notify (&new_tc0->connection, 0))
2480 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2481 tcp_connection_cleanup (new_tc0);
2482 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2486 new_tc0->tx_fifo_size =
2487 transport_tx_fifo_size (&new_tc0->connection);
2488 /* Update rtt with the syn-ack sample */
2489 tcp_estimate_initial_rtt (new_tc0);
2490 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2491 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2493 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2496 new_tc0->state = TCP_STATE_SYN_RCVD;
2498 /* Notify app that we have connection */
2499 if (session_stream_connect_notify (&new_tc0->connection, 0))
2501 tcp_connection_cleanup (new_tc0);
2502 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2503 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2504 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2508 new_tc0->tx_fifo_size =
2509 transport_tx_fifo_size (&new_tc0->connection);
2510 new_tc0->rtt_ts = 0;
2511 tcp_init_snd_vars (new_tc0);
2512 tcp_send_synack (new_tc0);
2513 error0 = TCP_ERROR_SYNS_RCVD;
2517 /* Read data, if any */
2518 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2520 clib_warning ("rcvd data in syn-sent");
2521 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2522 if (error0 == TCP_ERROR_ACK_OK)
2523 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2527 tcp_program_ack (new_tc0);
2532 tcp_inc_counter (syn_sent, error0, 1);
2533 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2535 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2536 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2537 clib_memcpy_fast (&t0->tcp_connection, tc0,
2538 sizeof (t0->tcp_connection));
2542 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2544 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2545 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2547 return from_frame->n_vectors;
2550 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2551 vlib_node_runtime_t * node,
2552 vlib_frame_t * from_frame)
2554 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2557 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2558 vlib_node_runtime_t * node,
2559 vlib_frame_t * from_frame)
2561 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2565 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2567 .name = "tcp4-syn-sent",
2568 /* Takes a vector of packets. */
2569 .vector_size = sizeof (u32),
2570 .n_errors = TCP_N_ERROR,
2571 .error_strings = tcp_error_strings,
2572 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2575 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2576 foreach_tcp_state_next
2579 .format_trace = format_tcp_rx_trace_short,
2584 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2586 .name = "tcp6-syn-sent",
2587 /* Takes a vector of packets. */
2588 .vector_size = sizeof (u32),
2589 .n_errors = TCP_N_ERROR,
2590 .error_strings = tcp_error_strings,
2591 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2594 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2595 foreach_tcp_state_next
2598 .format_trace = format_tcp_rx_trace_short,
2603 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2604 * as per RFC793 p. 64
2607 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2608 vlib_frame_t * from_frame, int is_ip4)
2610 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2611 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2612 u32 n_left_from, *from, max_dequeue;
2614 from = first_buffer = vlib_frame_vector_args (from_frame);
2615 n_left_from = from_frame->n_vectors;
2617 while (n_left_from > 0)
2619 u32 bi0, error0 = TCP_ERROR_NONE;
2620 tcp_header_t *tcp0 = 0;
2621 tcp_connection_t *tc0;
2629 b0 = vlib_get_buffer (vm, bi0);
2630 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2632 if (PREDICT_FALSE (tc0 == 0))
2634 error0 = TCP_ERROR_INVALID_CONNECTION;
2638 tcp0 = tcp_buffer_hdr (b0);
2639 is_fin0 = tcp_is_fin (tcp0);
2643 tcp_connection_t *tmp;
2644 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2646 if (tmp->state != tc0->state)
2648 if (tc0->state != TCP_STATE_CLOSED)
2649 clib_warning ("state changed");
2655 * Special treatment for CLOSED
2657 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2659 error0 = TCP_ERROR_CONNECTION_CLOSED;
2664 * For all other states (except LISTEN)
2667 /* 1-4: check SEQ, RST, SYN */
2668 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2671 /* 5: check the ACK field */
2674 case TCP_STATE_SYN_RCVD:
2676 /* Make sure the segment is exactly right */
2677 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2679 tcp_connection_reset (tc0);
2680 error0 = TCP_ERROR_SEGMENT_INVALID;
2685 * If the segment acknowledgment is not acceptable, form a
2687 * <SEQ=SEG.ACK><CTL=RST>
2690 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2692 tcp_connection_reset (tc0);
2696 /* Update rtt and rto */
2697 tcp_estimate_initial_rtt (tc0);
2699 /* Switch state to ESTABLISHED */
2700 tc0->state = TCP_STATE_ESTABLISHED;
2701 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2703 /* Initialize session variables */
2704 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2705 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2706 << tc0->rcv_opts.wscale;
2707 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2708 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2710 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2711 tcp_retransmit_timer_reset (tc0);
2712 if (session_stream_accept_notify (&tc0->connection))
2714 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2715 tcp_connection_reset (tc0);
2718 error0 = TCP_ERROR_ACK_OK;
2720 case TCP_STATE_ESTABLISHED:
2721 /* We can get packets in established state here because they
2722 * were enqueued before state change */
2723 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2727 case TCP_STATE_FIN_WAIT_1:
2728 /* In addition to the processing for the ESTABLISHED state, if
2729 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2730 * continue processing in that state. */
2731 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2734 /* Still have to send the FIN */
2735 if (tc0->flags & TCP_CONN_FINPNDG)
2737 /* TX fifo finally drained */
2738 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2739 if (max_dequeue <= tc0->burst_acked)
2741 /* If a fin was received and data was acked extend wait */
2742 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
2743 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2744 tcp_cfg.closewait_time);
2746 /* If FIN is ACKed */
2747 else if (tc0->snd_una == tc0->snd_nxt)
2749 /* Stop all retransmit timers because we have nothing more
2751 tcp_connection_timers_reset (tc0);
2753 /* We already have a FIN but didn't transition to CLOSING
2754 * because of outstanding tx data. Close the connection. */
2755 if (tc0->flags & TCP_CONN_FINRCVD)
2757 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2758 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE,
2759 tcp_cfg.cleanup_time);
2760 session_transport_closed_notify (&tc0->connection);
2764 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2765 /* Enable waitclose because we're willing to wait for peer's
2766 * FIN but not indefinitely. */
2767 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait2_time);
2769 /* Don't try to deq the FIN acked */
2770 if (tc0->burst_acked > 1)
2771 session_tx_fifo_dequeue_drop (&tc0->connection,
2772 tc0->burst_acked - 1);
2773 tc0->burst_acked = 0;
2776 case TCP_STATE_FIN_WAIT_2:
2777 /* In addition to the processing for the ESTABLISHED state, if
2778 * the retransmission queue is empty, the user's CLOSE can be
2779 * acknowledged ("ok") but do not delete the TCB. */
2780 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2782 tc0->burst_acked = 0;
2784 case TCP_STATE_CLOSE_WAIT:
2785 /* Do the same processing as for the ESTABLISHED state. */
2786 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2789 if (!(tc0->flags & TCP_CONN_FINPNDG))
2792 /* Still have outstanding tx data */
2793 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2794 if (max_dequeue > tc0->burst_acked)
2798 tcp_connection_timers_reset (tc0);
2799 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2800 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2802 case TCP_STATE_CLOSING:
2803 /* In addition to the processing for the ESTABLISHED state, if
2804 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2805 * otherwise ignore the segment. */
2806 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2809 if (tc0->snd_una != tc0->snd_nxt)
2812 tcp_connection_timers_reset (tc0);
2813 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2814 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2815 session_transport_closed_notify (&tc0->connection);
2819 case TCP_STATE_LAST_ACK:
2820 /* The only thing that [should] arrive in this state is an
2821 * acknowledgment of our FIN. If our FIN is now acknowledged,
2822 * delete the TCB, enter the CLOSED state, and return. */
2824 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2827 /* Apparently our ACK for the peer's FIN was lost */
2828 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2834 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2835 session_transport_closed_notify (&tc0->connection);
2837 /* Don't free the connection from the data path since
2838 * we can't ensure that we have no packets already enqueued
2839 * to output. Rely instead on the waitclose timer */
2840 tcp_connection_timers_reset (tc0);
2841 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
2846 case TCP_STATE_TIME_WAIT:
2847 /* The only thing that can arrive in this state is a
2848 * retransmission of the remote FIN. Acknowledge it, and restart
2849 * the 2 MSL timeout. */
2851 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2857 tcp_program_ack (tc0);
2858 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2866 /* 6: check the URG bit TODO */
2868 /* 7: process the segment text */
2871 case TCP_STATE_ESTABLISHED:
2872 case TCP_STATE_FIN_WAIT_1:
2873 case TCP_STATE_FIN_WAIT_2:
2874 if (vnet_buffer (b0)->tcp.data_len)
2875 error0 = tcp_segment_rcv (wrk, tc0, b0);
2877 case TCP_STATE_CLOSE_WAIT:
2878 case TCP_STATE_CLOSING:
2879 case TCP_STATE_LAST_ACK:
2880 case TCP_STATE_TIME_WAIT:
2881 /* This should not occur, since a FIN has been received from the
2882 * remote side. Ignore the segment text. */
2886 /* 8: check the FIN bit */
2890 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2894 case TCP_STATE_ESTABLISHED:
2895 /* Account for the FIN and send ack */
2897 tcp_program_ack (tc0);
2898 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2899 tcp_program_disconnect (wrk, tc0);
2900 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
2902 case TCP_STATE_SYN_RCVD:
2903 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2904 * notified yet, set a cleanup timer instead of relying on
2905 * disconnect notify and the implicit close call. */
2906 tcp_connection_timers_reset (tc0);
2909 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2910 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2912 case TCP_STATE_CLOSE_WAIT:
2913 case TCP_STATE_CLOSING:
2914 case TCP_STATE_LAST_ACK:
2917 case TCP_STATE_FIN_WAIT_1:
2920 if (tc0->flags & TCP_CONN_FINPNDG)
2922 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
2923 * sending it. Since we already received a fin, do not wait
2925 tc0->flags |= TCP_CONN_FINRCVD;
2926 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2927 tcp_cfg.closewait_time);
2931 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
2932 tcp_program_ack (tc0);
2933 /* Wait for ACK for our FIN but not forever */
2934 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2935 tcp_cfg.closing_time);
2938 case TCP_STATE_FIN_WAIT_2:
2939 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2941 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2942 tcp_connection_timers_reset (tc0);
2943 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2944 tcp_program_ack (tc0);
2945 session_transport_closed_notify (&tc0->connection);
2947 case TCP_STATE_TIME_WAIT:
2948 /* Remain in the TIME-WAIT state. Restart the time-wait
2951 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2954 error0 = TCP_ERROR_FIN_RCVD;
2958 tcp_inc_counter (rcv_process, error0, 1);
2959 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2961 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2962 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2966 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2968 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
2969 tcp_handle_postponed_dequeues (wrk);
2970 tcp_handle_disconnects (wrk);
2971 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2973 return from_frame->n_vectors;
2976 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
2977 vlib_node_runtime_t * node,
2978 vlib_frame_t * from_frame)
2980 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2983 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
2984 vlib_node_runtime_t * node,
2985 vlib_frame_t * from_frame)
2987 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2991 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2993 .name = "tcp4-rcv-process",
2994 /* Takes a vector of packets. */
2995 .vector_size = sizeof (u32),
2996 .n_errors = TCP_N_ERROR,
2997 .error_strings = tcp_error_strings,
2998 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3001 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3002 foreach_tcp_state_next
3005 .format_trace = format_tcp_rx_trace_short,
3010 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3012 .name = "tcp6-rcv-process",
3013 /* Takes a vector of packets. */
3014 .vector_size = sizeof (u32),
3015 .n_errors = TCP_N_ERROR,
3016 .error_strings = tcp_error_strings,
3017 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3020 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3021 foreach_tcp_state_next
3024 .format_trace = format_tcp_rx_trace_short,
3029 * LISTEN state processing as per RFC 793 p. 65
3032 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3033 vlib_frame_t * from_frame, int is_ip4)
3035 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3036 u32 my_thread_index = vm->thread_index;
3038 from = first_buffer = vlib_frame_vector_args (from_frame);
3039 n_left_from = from_frame->n_vectors;
3041 while (n_left_from > 0)
3046 tcp_header_t *th0 = 0;
3047 tcp_connection_t *lc0;
3050 tcp_connection_t *child0;
3051 u32 error0 = TCP_ERROR_NONE;
3057 b0 = vlib_get_buffer (vm, bi0);
3058 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3062 ip40 = vlib_buffer_get_current (b0);
3063 th0 = ip4_next_header (ip40);
3067 ip60 = vlib_buffer_get_current (b0);
3068 th0 = ip6_next_header (ip60);
3071 /* Create child session. For syn-flood protection use filter */
3073 /* 1. first check for an RST: handled in dispatch */
3074 /* if (tcp_rst (th0))
3078 /* 2. second check for an ACK: handled in dispatch */
3079 /* if (tcp_ack (th0))
3081 tcp_send_reset (b0, is_ip4);
3086 /* 3. check for a SYN (did that already) */
3088 /* Make sure connection wasn't just created */
3089 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3091 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3093 error0 = TCP_ERROR_CREATE_EXISTS;
3097 /* Create child session and send SYN-ACK */
3098 child0 = tcp_connection_alloc (my_thread_index);
3099 child0->c_lcl_port = th0->dst_port;
3100 child0->c_rmt_port = th0->src_port;
3101 child0->c_is_ip4 = is_ip4;
3102 child0->state = TCP_STATE_SYN_RCVD;
3103 child0->c_fib_index = lc0->c_fib_index;
3104 child0->cc_algo = lc0->cc_algo;
3108 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3109 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3113 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3114 sizeof (ip6_address_t));
3115 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3116 sizeof (ip6_address_t));
3119 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3121 error0 = TCP_ERROR_OPTIONS;
3122 tcp_connection_free (child0);
3126 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3127 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3128 child0->rcv_las = child0->rcv_nxt;
3129 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3131 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3132 * segments are used to initialize PAWS. */
3133 if (tcp_opts_tstamp (&child0->rcv_opts))
3135 child0->tsval_recent = child0->rcv_opts.tsval;
3136 child0->tsval_recent_age = tcp_time_now ();
3139 if (tcp_opts_wscale (&child0->rcv_opts))
3140 child0->snd_wscale = child0->rcv_opts.wscale;
3142 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3143 << child0->snd_wscale;
3144 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3145 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3147 tcp_connection_init_vars (child0);
3148 child0->rto = TCP_RTO_MIN;
3150 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3151 lc0->c_thread_index, 0 /* notify */ ))
3153 tcp_connection_cleanup (child0);
3154 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3158 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3159 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3160 tcp_send_synack (child0);
3164 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3166 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3167 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3168 clib_memcpy_fast (&t0->tcp_connection, lc0,
3169 sizeof (t0->tcp_connection));
3172 n_syns += (error0 == TCP_ERROR_NONE);
3175 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3176 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3178 return from_frame->n_vectors;
3181 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3182 vlib_frame_t * from_frame)
3184 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3187 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3188 vlib_frame_t * from_frame)
3190 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3194 VLIB_REGISTER_NODE (tcp4_listen_node) =
3196 .name = "tcp4-listen",
3197 /* Takes a vector of packets. */
3198 .vector_size = sizeof (u32),
3199 .n_errors = TCP_N_ERROR,
3200 .error_strings = tcp_error_strings,
3201 .n_next_nodes = TCP_LISTEN_N_NEXT,
3204 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3205 foreach_tcp_state_next
3208 .format_trace = format_tcp_rx_trace_short,
3213 VLIB_REGISTER_NODE (tcp6_listen_node) =
3215 .name = "tcp6-listen",
3216 /* Takes a vector of packets. */
3217 .vector_size = sizeof (u32),
3218 .n_errors = TCP_N_ERROR,
3219 .error_strings = tcp_error_strings,
3220 .n_next_nodes = TCP_LISTEN_N_NEXT,
3223 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3224 foreach_tcp_state_next
3227 .format_trace = format_tcp_rx_trace_short,
3231 typedef enum _tcp_input_next
3233 TCP_INPUT_NEXT_DROP,
3234 TCP_INPUT_NEXT_LISTEN,
3235 TCP_INPUT_NEXT_RCV_PROCESS,
3236 TCP_INPUT_NEXT_SYN_SENT,
3237 TCP_INPUT_NEXT_ESTABLISHED,
3238 TCP_INPUT_NEXT_RESET,
3239 TCP_INPUT_NEXT_PUNT,
3243 #define foreach_tcp4_input_next \
3244 _ (DROP, "ip4-drop") \
3245 _ (LISTEN, "tcp4-listen") \
3246 _ (RCV_PROCESS, "tcp4-rcv-process") \
3247 _ (SYN_SENT, "tcp4-syn-sent") \
3248 _ (ESTABLISHED, "tcp4-established") \
3249 _ (RESET, "tcp4-reset") \
3250 _ (PUNT, "ip4-punt")
3252 #define foreach_tcp6_input_next \
3253 _ (DROP, "ip6-drop") \
3254 _ (LISTEN, "tcp6-listen") \
3255 _ (RCV_PROCESS, "tcp6-rcv-process") \
3256 _ (SYN_SENT, "tcp6-syn-sent") \
3257 _ (ESTABLISHED, "tcp6-established") \
3258 _ (RESET, "tcp6-reset") \
3259 _ (PUNT, "ip6-punt")
3261 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3264 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3265 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3267 tcp_connection_t *tc;
3272 for (i = 0; i < n_bufs; i++)
3274 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3276 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3277 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3279 tcp = vlib_buffer_get_current (bs[i]);
3280 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3286 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3288 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3290 *next = TCP_INPUT_NEXT_DROP;
3292 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3294 *next = TCP_INPUT_NEXT_PUNT;
3295 *error = TCP_ERROR_PUNT;
3299 *next = TCP_INPUT_NEXT_RESET;
3300 *error = TCP_ERROR_NO_LISTENER;
3304 always_inline tcp_connection_t *
3305 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3306 u8 is_ip4, u8 is_nolookup)
3308 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3309 int n_advance_bytes, n_data_bytes;
3310 transport_connection_t *tc;
3316 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3317 int ip_hdr_bytes = ip4_header_bytes (ip4);
3318 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3320 *error = TCP_ERROR_LENGTH;
3323 tcp = ip4_next_header (ip4);
3324 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3325 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3326 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3328 /* Length check. Checksum computed by ipx_local no need to compute again */
3329 if (PREDICT_FALSE (n_data_bytes < 0))
3331 *error = TCP_ERROR_LENGTH;
3336 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3337 &ip4->src_address, tcp->dst_port,
3339 TRANSPORT_PROTO_TCP, thread_index,
3344 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3345 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3347 *error = TCP_ERROR_LENGTH;
3350 tcp = ip6_next_header (ip6);
3351 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3352 n_advance_bytes = tcp_header_bytes (tcp);
3353 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3355 n_advance_bytes += sizeof (ip6[0]);
3357 if (PREDICT_FALSE (n_data_bytes < 0))
3359 *error = TCP_ERROR_LENGTH;
3366 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3368 ip4_main_t *im = &ip4_main;
3369 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3370 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3373 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3375 tcp->dst_port, tcp->src_port,
3376 TRANSPORT_PROTO_TCP,
3377 thread_index, &result);
3383 (transport_connection_t *) tcp_connection_get (vnet_buffer (b)->
3384 tcp.connection_index,
3387 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3388 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3389 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3390 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3391 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3393 vnet_buffer (b)->tcp.flags = 0;
3395 *error = result ? TCP_ERROR_NONE + result : *error;
3397 return tcp_get_connection_from_transport (tc);
3401 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3402 vlib_buffer_t * b, u16 * next, u32 * error)
3407 tcp = tcp_buffer_hdr (b);
3408 flags = tcp->flags & filter_flags;
3409 *next = tm->dispatch_table[tc->state][flags].next;
3410 *error = tm->dispatch_table[tc->state][flags].error;
3413 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3414 || *next == TCP_INPUT_NEXT_RESET))
3416 /* Overload tcp flags to store state */
3417 tcp_state_t state = tc->state;
3418 vnet_buffer (b)->tcp.flags = tc->state;
3420 if (*error == TCP_ERROR_DISPATCH)
3421 clib_warning ("tcp conn %u disp error state %U flags %U",
3422 tc->c_c_index, format_tcp_state, state,
3423 format_tcp_flags, (int) flags);
3428 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3429 vlib_frame_t * frame, int is_ip4, u8 is_nolookup)
3431 u32 n_left_from, *from, thread_index = vm->thread_index;
3432 tcp_main_t *tm = vnet_get_tcp_main ();
3433 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3434 u16 nexts[VLIB_FRAME_SIZE], *next;
3436 tcp_set_time_now (tcp_get_worker (thread_index));
3438 from = vlib_frame_vector_args (frame);
3439 n_left_from = frame->n_vectors;
3440 vlib_get_buffers (vm, from, bufs, n_left_from);
3445 while (n_left_from >= 4)
3447 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3448 tcp_connection_t *tc0, *tc1;
3451 vlib_prefetch_buffer_header (b[2], STORE);
3452 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3454 vlib_prefetch_buffer_header (b[3], STORE);
3455 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3458 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3460 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3462 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4,
3465 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3467 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3468 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3470 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3471 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3473 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3474 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3478 if (PREDICT_TRUE (tc0 != 0))
3480 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3481 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3482 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3485 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3487 if (PREDICT_TRUE (tc1 != 0))
3489 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3490 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3491 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3494 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3501 while (n_left_from > 0)
3503 tcp_connection_t *tc0;
3504 u32 error0 = TCP_ERROR_NO_LISTENER;
3506 if (n_left_from > 1)
3508 vlib_prefetch_buffer_header (b[1], STORE);
3509 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3512 next[0] = TCP_INPUT_NEXT_DROP;
3513 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3515 if (PREDICT_TRUE (tc0 != 0))
3517 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3518 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3519 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3522 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3529 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3530 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3532 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3533 return frame->n_vectors;
3536 VLIB_NODE_FN (tcp4_input_nolookup_node) (vlib_main_t * vm,
3537 vlib_node_runtime_t * node,
3538 vlib_frame_t * from_frame)
3540 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3541 1 /* is_nolookup */ );
3544 VLIB_NODE_FN (tcp6_input_nolookup_node) (vlib_main_t * vm,
3545 vlib_node_runtime_t * node,
3546 vlib_frame_t * from_frame)
3548 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3549 1 /* is_nolookup */ );
3553 VLIB_REGISTER_NODE (tcp4_input_nolookup_node) =
3555 .name = "tcp4-input-nolookup",
3556 /* Takes a vector of packets. */
3557 .vector_size = sizeof (u32),
3558 .n_errors = TCP_N_ERROR,
3559 .error_strings = tcp_error_strings,
3560 .n_next_nodes = TCP_INPUT_N_NEXT,
3563 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3564 foreach_tcp4_input_next
3567 .format_buffer = format_tcp_header,
3568 .format_trace = format_tcp_rx_trace,
3573 VLIB_REGISTER_NODE (tcp6_input_nolookup_node) =
3575 .name = "tcp6-input-nolookup",
3576 /* Takes a vector of packets. */
3577 .vector_size = sizeof (u32),
3578 .n_errors = TCP_N_ERROR,
3579 .error_strings = tcp_error_strings,
3580 .n_next_nodes = TCP_INPUT_N_NEXT,
3583 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3584 foreach_tcp6_input_next
3587 .format_buffer = format_tcp_header,
3588 .format_trace = format_tcp_rx_trace,
3592 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3593 vlib_frame_t * from_frame)
3595 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3596 0 /* is_nolookup */ );
3599 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3600 vlib_frame_t * from_frame)
3602 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3603 0 /* is_nolookup */ );
3607 VLIB_REGISTER_NODE (tcp4_input_node) =
3609 .name = "tcp4-input",
3610 /* Takes a vector of packets. */
3611 .vector_size = sizeof (u32),
3612 .n_errors = TCP_N_ERROR,
3613 .error_strings = tcp_error_strings,
3614 .n_next_nodes = TCP_INPUT_N_NEXT,
3617 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3618 foreach_tcp4_input_next
3621 .format_buffer = format_tcp_header,
3622 .format_trace = format_tcp_rx_trace,
3627 VLIB_REGISTER_NODE (tcp6_input_node) =
3629 .name = "tcp6-input",
3630 /* Takes a vector of packets. */
3631 .vector_size = sizeof (u32),
3632 .n_errors = TCP_N_ERROR,
3633 .error_strings = tcp_error_strings,
3634 .n_next_nodes = TCP_INPUT_N_NEXT,
3637 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3638 foreach_tcp6_input_next
3641 .format_buffer = format_tcp_header,
3642 .format_trace = format_tcp_rx_trace,
3646 #ifndef CLIB_MARCH_VARIANT
3648 tcp_dispatch_table_init (tcp_main_t * tm)
3651 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3652 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3654 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3655 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3658 #define _(t,f,n,e) \
3660 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3661 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3664 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3665 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3666 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3667 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3668 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3669 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3670 TCP_ERROR_ACK_INVALID);
3671 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3672 TCP_ERROR_SEGMENT_INVALID);
3673 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3674 TCP_ERROR_SEGMENT_INVALID);
3675 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3676 TCP_ERROR_INVALID_CONNECTION);
3677 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3678 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3679 TCP_ERROR_SEGMENT_INVALID);
3680 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3681 TCP_ERROR_SEGMENT_INVALID);
3682 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3684 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3685 TCP_ERROR_SEGMENT_INVALID);
3686 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3687 TCP_ERROR_SEGMENT_INVALID);
3688 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3689 TCP_ERROR_SEGMENT_INVALID);
3690 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3691 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3692 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3693 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3694 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3695 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3697 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3698 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3700 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3702 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3703 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3704 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3705 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3707 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3709 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3710 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3711 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3713 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3714 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3715 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3716 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3717 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3718 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3719 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3720 /* SYN-ACK for a SYN */
3721 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3723 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3724 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3725 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3727 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3728 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3730 /* ACK for for established connection -> tcp-established. */
3731 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3732 /* FIN for for established connection -> tcp-established. */
3733 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3734 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3736 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3738 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3739 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3740 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3742 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3743 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3744 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3745 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3746 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3747 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3748 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3749 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3751 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3752 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3754 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3756 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3757 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3758 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3759 /* ACK or FIN-ACK to our FIN */
3760 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3761 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3763 /* FIN in reply to our FIN from the other side */
3764 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3765 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3766 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3768 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3769 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3770 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3771 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3772 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3773 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3774 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3776 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3777 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3778 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3779 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3781 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3783 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3784 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3785 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3786 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3788 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3789 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3790 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3791 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3793 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3795 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3796 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3797 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3798 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3800 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3801 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3803 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3805 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3806 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3807 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3809 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3810 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3811 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3812 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3813 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3814 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3815 /* FIN confirming that the peer (app) has closed */
3816 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3817 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3818 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3820 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3821 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3823 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3824 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3826 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3827 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3829 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3830 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3831 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3832 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3834 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3836 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3837 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3838 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3840 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3841 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3842 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3843 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3844 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3845 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3846 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3847 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3849 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3850 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3852 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3854 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3855 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3856 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3857 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3858 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3860 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3861 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3863 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3864 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3865 * incoming segment not containing a RST causes a RST to be sent in
3867 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3868 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3869 TCP_ERROR_CONNECTION_CLOSED);
3870 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3871 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3872 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3877 static clib_error_t *
3878 tcp_input_init (vlib_main_t * vm)
3880 clib_error_t *error = 0;
3881 tcp_main_t *tm = vnet_get_tcp_main ();
3883 if ((error = vlib_call_init_function (vm, tcp_init)))
3886 /* Initialize dispatch table. */
3887 tcp_dispatch_table_init (tm);
3892 VLIB_INIT_FUNCTION (tcp_input_init);
3894 #endif /* CLIB_MARCH_VARIANT */
3897 * fd.io coding-style-patch-verification: ON
3900 * eval: (c-set-style "gnu")