2 * Copyright (c) 2016-2019 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #include <vppinfra/sparse_vec.h>
17 #include <vnet/fib/ip4_fib.h>
18 #include <vnet/fib/ip6_fib.h>
19 #include <vnet/tcp/tcp_packet.h>
20 #include <vnet/tcp/tcp.h>
21 #include <vnet/session/session.h>
24 static char *tcp_error_strings[] = {
25 #define tcp_error(n,s) s,
26 #include <vnet/tcp/tcp_error.def>
30 /* All TCP nodes have the same outgoing arcs */
31 #define foreach_tcp_state_next \
32 _ (DROP4, "ip4-drop") \
33 _ (DROP6, "ip6-drop") \
34 _ (TCP4_OUTPUT, "tcp4-output") \
35 _ (TCP6_OUTPUT, "tcp6-output")
37 typedef enum _tcp_established_next
39 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
40 foreach_tcp_state_next
42 TCP_ESTABLISHED_N_NEXT,
43 } tcp_established_next_t;
45 typedef enum _tcp_rcv_process_next
47 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
48 foreach_tcp_state_next
50 TCP_RCV_PROCESS_N_NEXT,
51 } tcp_rcv_process_next_t;
53 typedef enum _tcp_syn_sent_next
55 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
56 foreach_tcp_state_next
59 } tcp_syn_sent_next_t;
61 typedef enum _tcp_listen_next
63 #define _(s,n) TCP_LISTEN_NEXT_##s,
64 foreach_tcp_state_next
69 /* Generic, state independent indices */
70 typedef enum _tcp_state_next
72 #define _(s,n) TCP_NEXT_##s,
73 foreach_tcp_state_next
78 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
79 : TCP_NEXT_TCP6_OUTPUT)
81 #define tcp_next_drop(is_ip4) (is_ip4 ? TCP_NEXT_DROP4 \
85 * Validate segment sequence number. As per RFC793:
87 * Segment Receive Test
89 * ------- ------- -------------------------------------------
90 * 0 0 SEG.SEQ = RCV.NXT
91 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
93 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
94 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
96 * This ultimately consists in checking if segment falls within the window.
97 * The one important difference compared to RFC793 is that we use rcv_las,
98 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
99 * peer's reference when computing our receive window.
102 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
103 * however, is too strict when we have retransmits. Instead we just check that
104 * the seq is not beyond the right edge and that the end of the segment is not
105 * less than the left edge.
107 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
108 * use rcv_nxt in the right edge window test instead of rcv_las.
112 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
114 return (seq_geq (end_seq, tc->rcv_las)
115 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
119 * Parse TCP header options.
121 * @param th TCP header
122 * @param to TCP options data structure to be populated
123 * @param is_syn set if packet is syn
124 * @return -1 if parsing failed
127 tcp_options_parse (tcp_header_t * th, tcp_options_t * to, u8 is_syn)
130 u8 opt_len, opts_len, kind;
134 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
135 data = (const u8 *) (th + 1);
137 /* Zero out all flags but those set in SYN */
138 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
139 | TCP_OPTS_FLAG_TSTAMP | TCP_OPTION_MSS);
141 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
145 /* Get options length */
146 if (kind == TCP_OPTION_EOL)
148 else if (kind == TCP_OPTION_NOOP)
160 /* weird option length */
161 if (opt_len < 2 || opt_len > opts_len)
171 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
173 to->flags |= TCP_OPTS_FLAG_MSS;
174 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
177 case TCP_OPTION_WINDOW_SCALE:
180 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
182 to->flags |= TCP_OPTS_FLAG_WSCALE;
183 to->wscale = data[2];
184 if (to->wscale > TCP_MAX_WND_SCALE)
185 to->wscale = TCP_MAX_WND_SCALE;
188 case TCP_OPTION_TIMESTAMP:
190 to->flags |= TCP_OPTS_FLAG_TSTAMP;
191 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
192 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
194 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
195 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
198 case TCP_OPTION_SACK_PERMITTED:
201 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
202 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
204 case TCP_OPTION_SACK_BLOCK:
205 /* If SACK permitted was not advertised or a SYN, break */
206 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
209 /* If too short or not correctly formatted, break */
210 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
213 to->flags |= TCP_OPTS_FLAG_SACK;
214 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
215 vec_reset_length (to->sacks);
216 for (j = 0; j < to->n_sack_blocks; j++)
218 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
219 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
220 vec_add1 (to->sacks, b);
224 /* Nothing to see here */
232 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
233 * timestamp to echo and it's less than tsval_recent, drop segment
234 * but still send an ACK in order to retain TCP's mechanism for detecting
235 * and recovering from half-open connections
237 * Or at least that's what the theory says. It seems that this might not work
238 * very well with packet reordering and fast retransmit. XXX
241 tcp_segment_check_paws (tcp_connection_t * tc)
243 return tcp_opts_tstamp (&tc->rcv_opts)
244 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
248 * Update tsval recent
251 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
254 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
255 * of an incoming segment:
256 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
257 * then the TSval from the segment is copied to TS.Recent;
258 * otherwise, the TSval is ignored.
260 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
261 && seq_leq (tc->rcv_las, seq_end))
263 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
264 tc->tsval_recent = tc->rcv_opts.tsval;
265 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
270 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
272 * It first verifies if segment has a wrapped sequence number (PAWS) and then
273 * does the processing associated to the first four steps (ignoring security
274 * and precedence): sequence number, rst bit and syn bit checks.
276 * @return 0 if segments passes validation.
279 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
280 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
282 /* We could get a burst of RSTs interleaved with acks */
283 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
285 tcp_send_reset (tc0);
286 *error0 = TCP_ERROR_CONNECTION_CLOSED;
290 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
292 *error0 = TCP_ERROR_SEGMENT_INVALID;
296 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
298 *error0 = TCP_ERROR_OPTIONS;
302 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
304 *error0 = TCP_ERROR_PAWS;
305 TCP_EVT (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
306 vnet_buffer (b0)->tcp.seq_end);
308 /* If it just so happens that a segment updates tsval_recent for a
309 * segment over 24 days old, invalidate tsval_recent. */
310 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
311 tcp_time_now_w_thread (tc0->c_thread_index)))
313 tc0->tsval_recent = tc0->rcv_opts.tsval;
314 clib_warning ("paws failed: 24-day old segment");
316 /* Drop after ack if not rst. Resets can fail paws check as per
317 * RFC 7323 sec. 5.2: When an <RST> segment is received, it MUST NOT
318 * be subjected to the PAWS check by verifying an acceptable value in
320 else if (!tcp_rst (th0))
322 tcp_program_ack (tc0);
323 TCP_EVT (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
328 /* 1st: check sequence number */
329 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
330 vnet_buffer (b0)->tcp.seq_end))
332 /* SYN/SYN-ACK retransmit */
334 && vnet_buffer (b0)->tcp.seq_number == tc0->rcv_nxt - 1)
336 tcp_options_parse (th0, &tc0->rcv_opts, 1);
337 if (tc0->state == TCP_STATE_SYN_RCVD)
339 tcp_send_synack (tc0);
340 TCP_EVT (TCP_EVT_SYN_RCVD, tc0, 0);
341 *error0 = TCP_ERROR_SYNS_RCVD;
345 tcp_program_ack (tc0);
346 TCP_EVT (TCP_EVT_SYNACK_RCVD, tc0);
347 *error0 = TCP_ERROR_SYN_ACKS_RCVD;
352 /* If our window is 0 and the packet is in sequence, let it pass
353 * through for ack processing. It should be dropped later. */
354 if (tc0->rcv_wnd < tc0->snd_mss
355 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
358 /* If we entered recovery and peer did so as well, there's a chance that
359 * dup acks won't be acceptable on either end because seq_end may be less
360 * than rcv_las. This can happen if acks are lost in both directions. */
361 if (tcp_in_recovery (tc0)
362 && seq_geq (vnet_buffer (b0)->tcp.seq_number,
363 tc0->rcv_las - tc0->rcv_wnd)
364 && seq_leq (vnet_buffer (b0)->tcp.seq_end,
365 tc0->rcv_nxt + tc0->rcv_wnd))
368 *error0 = TCP_ERROR_RCV_WND;
370 /* If we advertised a zero rcv_wnd and the segment is in the past or the
371 * next one that we expect, it is probably a window probe */
372 if ((tc0->flags & TCP_CONN_ZERO_RWND_SENT)
373 && seq_lt (vnet_buffer (b0)->tcp.seq_end,
374 tc0->rcv_las + tc0->rcv_opts.mss))
375 *error0 = TCP_ERROR_ZERO_RWND;
377 tc0->errors.below_data_wnd += seq_lt (vnet_buffer (b0)->tcp.seq_end,
380 /* If not RST, send dup ack */
383 tcp_program_dupack (tc0);
384 TCP_EVT (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
392 /* 2nd: check the RST bit */
393 if (PREDICT_FALSE (tcp_rst (th0)))
395 tcp_connection_reset (tc0);
396 *error0 = TCP_ERROR_RST_RCVD;
400 /* 3rd: check security and precedence (skip) */
402 /* 4th: check the SYN bit (in window) */
403 if (PREDICT_FALSE (tcp_syn (th0)))
405 /* As per RFC5961 send challenge ack instead of reset */
406 tcp_program_ack (tc0);
407 *error0 = TCP_ERROR_SPURIOUS_SYN;
411 /* If segment in window, save timestamp */
412 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
413 vnet_buffer (b0)->tcp.seq_end);
421 tcp_rcv_ack_no_cc (tcp_connection_t * tc, vlib_buffer_t * b, u32 * error)
423 /* SND.UNA =< SEG.ACK =< SND.NXT */
424 if (!(seq_leq (tc->snd_una, vnet_buffer (b)->tcp.ack_number)
425 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
427 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
428 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
430 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
433 *error = TCP_ERROR_ACK_INVALID;
438 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
439 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
440 *error = TCP_ERROR_ACK_OK;
445 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
447 * Note that although the original article, srtt and rttvar are scaled
448 * to minimize round-off errors, here we don't. Instead, we rely on
449 * better precision time measurements.
451 * TODO support us rtt resolution
454 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
460 err = mrtt - tc->srtt;
462 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
463 * The increase should be bound */
464 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
465 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
466 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
470 /* First measurement. */
472 tc->rttvar = mrtt >> 1;
476 #ifndef CLIB_MARCH_VARIANT
478 tcp_update_rto (tcp_connection_t * tc)
480 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
481 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
483 #endif /* CLIB_MARCH_VARIANT */
486 * Update RTT estimate and RTO timer
488 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
489 * timing. Middle boxes are known to fiddle with TCP options so we
490 * should give higher priority to ACK timing.
492 * This should be called only if previously sent bytes have been acked.
494 * return 1 if valid rtt 0 otherwise
497 tcp_update_rtt (tcp_connection_t * tc, tcp_rate_sample_t * rs, u32 ack)
501 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
502 * RTT because they're ambiguous. */
503 if (tcp_in_cong_recovery (tc))
505 /* Accept rtt estimates for samples that have not been retransmitted */
506 if ((tc->flags & TCP_CONN_RATE_SAMPLE) && !(rs->flags & TCP_BTS_IS_RXT))
508 mrtt = rs->rtt_time * THZ;
511 if (tcp_in_recovery (tc))
516 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
518 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
519 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
520 mrtt = clib_max ((u32) (sample * THZ), 1);
521 /* Allow measuring of a new RTT */
524 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
525 * snd_una, i.e., the left side of the send window:
526 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
527 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
529 u32 now = tcp_tstamp (tc);
530 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
535 /* Ignore dubious measurements */
536 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
539 tcp_estimate_rtt (tc, mrtt);
543 /* If we got here something must've been ACKed so make sure boff is 0,
544 * even if mrtt is not valid since we update the rto lower */
552 tcp_estimate_initial_rtt (tcp_connection_t * tc)
554 u8 thread_index = vlib_num_workers ()? 1 : 0;
559 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
560 tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001);
561 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
566 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
567 mrtt = clib_max (mrtt, 1);
568 /* Due to retransmits we don't know the initial mrtt */
569 if (tc->rto_boff && mrtt > 1 * THZ)
571 tc->mrtt_us = (f64) mrtt *TCP_TICK;
574 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
575 tcp_estimate_rtt (tc, mrtt);
580 * Dequeue bytes for connections that have received acks in last burst
583 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
585 u32 thread_index = wrk->vm->thread_index;
586 u32 *pending_deq_acked;
587 tcp_connection_t *tc;
590 if (!vec_len (wrk->pending_deq_acked))
593 pending_deq_acked = wrk->pending_deq_acked;
594 for (i = 0; i < vec_len (pending_deq_acked); i++)
596 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
597 tc->flags &= ~TCP_CONN_DEQ_PENDING;
599 if (PREDICT_FALSE (!tc->burst_acked))
602 /* Dequeue the newly ACKed bytes */
603 session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
605 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
607 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
609 if (seq_leq (tc->psh_seq, tc->snd_una))
610 tc->flags &= ~TCP_CONN_PSH_PENDING;
613 /* If everything has been acked, stop retransmit timer
614 * otherwise update. */
615 tcp_retransmit_timer_update (tc);
617 /* Update pacer based on our new cwnd estimate */
618 tcp_connection_tx_pacer_update (tc);
620 _vec_len (wrk->pending_deq_acked) = 0;
624 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
626 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
628 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
629 tc->flags |= TCP_CONN_DEQ_PENDING;
631 tc->burst_acked += tc->bytes_acked;
635 * Check if duplicate ack as per RFC5681 Sec. 2
638 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
641 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
642 && seq_gt (tc->snd_nxt, tc->snd_una)
643 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
644 && (prev_snd_wnd == tc->snd_wnd));
648 * Checks if ack is a congestion control event.
651 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
652 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
654 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
655 * defined to be 'duplicate' */
656 *is_dack = tc->sack_sb.last_sacked_bytes
657 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
659 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
662 #ifndef CLIB_MARCH_VARIANT
664 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
666 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
667 return hole - sb->holes;
671 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
673 return hole->end - hole->start;
676 sack_scoreboard_hole_t *
677 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
679 if (index != TCP_INVALID_SACK_HOLE_INDEX)
680 return pool_elt_at_index (sb->holes, index);
684 sack_scoreboard_hole_t *
685 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
687 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
688 return pool_elt_at_index (sb->holes, hole->next);
692 sack_scoreboard_hole_t *
693 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
695 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
696 return pool_elt_at_index (sb->holes, hole->prev);
700 sack_scoreboard_hole_t *
701 scoreboard_first_hole (sack_scoreboard_t * sb)
703 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
704 return pool_elt_at_index (sb->holes, sb->head);
708 sack_scoreboard_hole_t *
709 scoreboard_last_hole (sack_scoreboard_t * sb)
711 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
712 return pool_elt_at_index (sb->holes, sb->tail);
717 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
719 sack_scoreboard_hole_t *next, *prev;
721 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
723 next = pool_elt_at_index (sb->holes, hole->next);
724 next->prev = hole->prev;
728 sb->tail = hole->prev;
731 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
733 prev = pool_elt_at_index (sb->holes, hole->prev);
734 prev->next = hole->next;
738 sb->head = hole->next;
741 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
742 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
744 /* Poison the entry */
746 clib_memset (hole, 0xfe, sizeof (*hole));
748 pool_put (sb->holes, hole);
751 static sack_scoreboard_hole_t *
752 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
755 sack_scoreboard_hole_t *hole, *next, *prev;
758 pool_get (sb->holes, hole);
759 clib_memset (hole, 0, sizeof (*hole));
763 hole_index = scoreboard_hole_index (sb, hole);
765 prev = scoreboard_get_hole (sb, prev_index);
768 hole->prev = prev_index;
769 hole->next = prev->next;
771 if ((next = scoreboard_next_hole (sb, hole)))
772 next->prev = hole_index;
774 sb->tail = hole_index;
776 prev->next = hole_index;
780 sb->head = hole_index;
781 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
782 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
787 #endif /* CLIB_MARCH_VARIANT */
789 #ifndef CLIB_MARCH_VARIANT
792 scoreboard_update_bytes (sack_scoreboard_t * sb, u32 ack, u32 snd_mss)
794 sack_scoreboard_hole_t *left, *right;
795 u32 sacked = 0, blks = 0, old_sacked;
797 old_sacked = sb->sacked_bytes;
799 sb->last_lost_bytes = 0;
801 sb->sacked_bytes = 0;
803 right = scoreboard_last_hole (sb);
806 sb->sacked_bytes = sb->high_sacked - ack;
810 if (seq_gt (sb->high_sacked, right->end))
812 sacked = sb->high_sacked - right->end;
816 while (sacked < (TCP_DUPACK_THRESHOLD - 1) * snd_mss
817 && blks < TCP_DUPACK_THRESHOLD)
820 sb->lost_bytes += scoreboard_hole_bytes (right);
822 left = scoreboard_prev_hole (sb, right);
825 ASSERT (right->start == ack || sb->is_reneging);
826 sacked += right->start - ack;
831 sacked += right->start - left->end;
836 /* right is first lost */
839 sb->lost_bytes += scoreboard_hole_bytes (right);
840 sb->last_lost_bytes += right->is_lost ? 0 : right->end - right->start;
842 left = scoreboard_prev_hole (sb, right);
845 ASSERT (right->start == ack || sb->is_reneging);
846 sacked += right->start - ack;
849 sacked += right->start - left->end;
853 sb->sacked_bytes = sacked;
854 sb->last_sacked_bytes = sacked - (old_sacked - sb->last_bytes_delivered);
858 * Figure out the next hole to retransmit
860 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
862 sack_scoreboard_hole_t *
863 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
864 sack_scoreboard_hole_t * start,
865 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
867 sack_scoreboard_hole_t *hole = 0;
869 hole = start ? start : scoreboard_first_hole (sb);
870 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
871 hole = scoreboard_next_hole (sb, hole);
873 /* Nothing, return */
876 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
880 /* Rule (1): if higher than rxt, less than high_sacked and lost */
881 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
883 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
887 /* Rule (2): available unsent data */
890 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
893 /* Rule (3): if hole not lost */
894 else if (seq_lt (hole->start, sb->high_sacked))
897 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
899 /* Rule (4): if hole beyond high_sacked */
902 ASSERT (seq_geq (hole->start, sb->high_sacked));
905 /* HighRxt MUST NOT be updated */
910 if (hole && seq_lt (sb->high_rxt, hole->start))
911 sb->high_rxt = hole->start;
915 #endif /* CLIB_MARCH_VARIANT */
918 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
920 sack_scoreboard_hole_t *hole;
921 hole = scoreboard_first_hole (sb);
924 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
925 sb->cur_rxt_hole = sb->head;
927 sb->high_rxt = snd_una;
928 sb->rescue_rxt = snd_una - 1;
931 #ifndef CLIB_MARCH_VARIANT
933 scoreboard_init (sack_scoreboard_t * sb)
935 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
936 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
937 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
941 scoreboard_clear (sack_scoreboard_t * sb)
943 sack_scoreboard_hole_t *hole;
944 while ((hole = scoreboard_first_hole (sb)))
946 scoreboard_remove_hole (sb, hole);
948 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
949 ASSERT (pool_elts (sb->holes) == 0);
950 sb->sacked_bytes = 0;
951 sb->last_sacked_bytes = 0;
952 sb->last_bytes_delivered = 0;
956 sb->last_lost_bytes = 0;
957 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
960 #endif /* CLIB_MARCH_VARIANT */
963 * Test that scoreboard is sane after recovery
965 * Returns 1 if scoreboard is empty or if first hole beyond
969 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
971 sack_scoreboard_hole_t *hole;
972 hole = scoreboard_first_hole (&tc->sack_sb);
973 return (!hole || (seq_geq (hole->start, tc->snd_una)
974 && seq_lt (hole->end, tc->snd_nxt)));
977 #ifndef CLIB_MARCH_VARIANT
980 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
982 sack_scoreboard_hole_t *hole, *next_hole;
983 sack_scoreboard_t *sb = &tc->sack_sb;
984 sack_block_t *blk, *rcv_sacks;
985 u32 blk_index = 0, i, j;
987 sb->last_sacked_bytes = 0;
988 sb->last_bytes_delivered = 0;
990 if (!tcp_opts_sack (&tc->rcv_opts)
991 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
994 /* Remove invalid blocks */
995 blk = tc->rcv_opts.sacks;
996 while (blk < vec_end (tc->rcv_opts.sacks))
998 if (seq_lt (blk->start, blk->end)
999 && seq_gt (blk->start, tc->snd_una)
1000 && seq_gt (blk->start, ack)
1001 && seq_lt (blk->start, tc->snd_nxt)
1002 && seq_leq (blk->end, tc->snd_nxt))
1007 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
1010 /* Add block for cumulative ack */
1011 if (seq_gt (ack, tc->snd_una))
1013 vec_add2 (tc->rcv_opts.sacks, blk, 1);
1014 blk->start = tc->snd_una;
1018 if (vec_len (tc->rcv_opts.sacks) == 0)
1021 tcp_scoreboard_trace_add (tc, ack);
1023 /* Make sure blocks are ordered */
1024 rcv_sacks = tc->rcv_opts.sacks;
1025 for (i = 0; i < vec_len (rcv_sacks); i++)
1026 for (j = i + 1; j < vec_len (rcv_sacks); j++)
1027 if (seq_lt (rcv_sacks[j].start, rcv_sacks[i].start))
1029 sack_block_t tmp = rcv_sacks[i];
1030 rcv_sacks[i] = rcv_sacks[j];
1034 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1036 /* Handle reneging as a special case */
1037 if (PREDICT_FALSE (sb->is_reneging))
1039 /* No holes, only sacked bytes */
1040 if (seq_leq (tc->snd_nxt, sb->high_sacked))
1042 /* No progress made so return */
1043 if (seq_leq (ack, tc->snd_una))
1046 /* Update sacked bytes delivered and return */
1047 sb->last_bytes_delivered = ack - tc->snd_una;
1048 sb->sacked_bytes -= sb->last_bytes_delivered;
1049 sb->is_reneging = seq_lt (ack, sb->high_sacked);
1053 /* New hole above high sacked. Add it and process normally */
1054 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1055 sb->high_sacked, tc->snd_nxt);
1056 sb->tail = scoreboard_hole_index (sb, hole);
1058 /* Not reneging and no holes. Insert the first that covers all
1059 * outstanding bytes */
1062 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1063 tc->snd_una, tc->snd_nxt);
1064 sb->tail = scoreboard_hole_index (sb, hole);
1066 sb->high_sacked = rcv_sacks[vec_len (rcv_sacks) - 1].end;
1070 /* If we have holes but snd_nxt is beyond the last hole, update
1071 * last hole end or add new hole after high sacked */
1072 hole = scoreboard_last_hole (sb);
1073 if (seq_gt (tc->snd_nxt, hole->end))
1075 if (seq_geq (hole->start, sb->high_sacked))
1077 hole->end = tc->snd_nxt;
1079 /* New hole after high sacked block */
1080 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1082 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1087 /* Keep track of max byte sacked for when the last hole
1089 sb->high_sacked = seq_max (rcv_sacks[vec_len (rcv_sacks) - 1].end,
1093 /* Walk the holes with the SACK blocks */
1094 hole = pool_elt_at_index (sb->holes, sb->head);
1096 if (PREDICT_FALSE (sb->is_reneging))
1097 sb->last_bytes_delivered += hole->start - tc->snd_una;
1099 while (hole && blk_index < vec_len (rcv_sacks))
1101 blk = &rcv_sacks[blk_index];
1102 if (seq_leq (blk->start, hole->start))
1104 /* Block covers hole. Remove hole */
1105 if (seq_geq (blk->end, hole->end))
1107 next_hole = scoreboard_next_hole (sb, hole);
1109 /* If covered by ack, compute delivered bytes */
1110 if (blk->end == ack)
1112 u32 sacked = next_hole ? next_hole->start : sb->high_sacked;
1113 if (PREDICT_FALSE (seq_lt (ack, sacked)))
1115 sb->last_bytes_delivered += ack - hole->end;
1116 sb->is_reneging = 1;
1120 sb->last_bytes_delivered += sacked - hole->end;
1121 sb->is_reneging = 0;
1124 scoreboard_remove_hole (sb, hole);
1127 /* Partial 'head' overlap */
1130 if (seq_gt (blk->end, hole->start))
1132 hole->start = blk->end;
1139 /* Hole must be split */
1140 if (seq_lt (blk->end, hole->end))
1142 u32 hole_index = scoreboard_hole_index (sb, hole);
1143 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1145 /* Pool might've moved */
1146 hole = scoreboard_get_hole (sb, hole_index);
1147 hole->end = blk->start;
1149 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1151 else if (seq_lt (blk->start, hole->end))
1153 hole->end = blk->start;
1155 hole = scoreboard_next_hole (sb, hole);
1159 scoreboard_update_bytes (sb, ack, tc->snd_mss);
1161 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1162 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1163 || sb->sacked_bytes <= tc->snd_nxt - seq_max (tc->snd_una, ack));
1164 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1165 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1166 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1167 || sb->is_reneging || sb->holes[sb->head].start == ack);
1168 ASSERT (sb->last_lost_bytes <= sb->lost_bytes);
1170 TCP_EVT (TCP_EVT_CC_SCOREBOARD, tc);
1172 #endif /* CLIB_MARCH_VARIANT */
1175 * Try to update snd_wnd based on feedback received from peer.
1177 * If successful, and new window is 'effectively' 0, activate persist
1181 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1183 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1184 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1185 if (seq_lt (tc->snd_wl1, seq)
1186 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1188 tc->snd_wnd = snd_wnd;
1191 TCP_EVT (TCP_EVT_SND_WND, tc);
1193 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1195 /* Set persist timer if not set and we just got 0 wnd */
1196 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1197 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1198 tcp_persist_timer_set (tc);
1202 tcp_persist_timer_reset (tc);
1203 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1206 tcp_update_rto (tc);
1212 #ifndef CLIB_MARCH_VARIANT
1214 * Init loss recovery/fast recovery.
1216 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1217 * updated in @ref tcp_cc_handle_event after fast retransmit
1220 tcp_cc_init_congestion (tcp_connection_t * tc)
1222 tcp_fastrecovery_on (tc);
1223 tc->snd_congestion = tc->snd_nxt;
1224 tc->cwnd_acc_bytes = 0;
1225 tc->snd_rxt_bytes = 0;
1226 tc->prev_ssthresh = tc->ssthresh;
1227 tc->prev_cwnd = tc->cwnd;
1228 tc->cc_algo->congestion (tc);
1229 tc->fr_occurences += 1;
1230 TCP_EVT (TCP_EVT_CC_EVT, tc, 4);
1232 #endif /* CLIB_MARCH_VARIANT */
1235 tcp_cc_recovery_exit (tcp_connection_t * tc)
1238 tcp_update_rto (tc);
1241 tcp_recovery_off (tc);
1242 TCP_EVT (TCP_EVT_CC_EVT, tc, 3);
1245 #ifndef CLIB_MARCH_VARIANT
1247 tcp_cc_fastrecovery_clear (tcp_connection_t * tc)
1249 tc->snd_rxt_bytes = 0;
1250 tc->rcv_dupacks = 0;
1253 tcp_fastrecovery_off (tc);
1254 tcp_fastrecovery_first_off (tc);
1255 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1257 TCP_EVT (TCP_EVT_CC_EVT, tc, 3);
1259 #endif /* CLIB_MARCH_VARIANT */
1262 tcp_cc_congestion_undo (tcp_connection_t * tc)
1264 tc->cwnd = tc->prev_cwnd;
1265 tc->ssthresh = tc->prev_ssthresh;
1266 tc->rcv_dupacks = 0;
1267 if (tcp_in_recovery (tc))
1269 tcp_cc_recovery_exit (tc);
1270 tc->snd_nxt = seq_max (tc->snd_nxt, tc->snd_congestion);
1272 else if (tcp_in_fastrecovery (tc))
1274 tcp_cc_fastrecovery_clear (tc);
1276 tcp_cc_undo_recovery (tc);
1277 ASSERT (tc->rto_boff == 0);
1278 TCP_EVT (TCP_EVT_CC_EVT, tc, 5);
1282 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1284 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1286 && tcp_opts_tstamp (&tc->rcv_opts)
1287 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1291 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1293 return (tcp_in_fastrecovery (tc)
1294 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1298 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1300 return (tcp_cc_is_spurious_timeout_rxt (tc)
1301 || tcp_cc_is_spurious_fast_rxt (tc));
1305 tcp_cc_recover (tcp_connection_t * tc)
1307 sack_scoreboard_hole_t *hole;
1309 ASSERT (tcp_in_cong_recovery (tc));
1311 hole = scoreboard_first_hole (&tc->sack_sb);
1312 if (hole && hole->start == tc->snd_una && hole->end == tc->snd_nxt)
1313 scoreboard_clear (&tc->sack_sb);
1315 if (tcp_cc_is_spurious_retransmit (tc))
1317 tcp_cc_congestion_undo (tc);
1321 if (tcp_in_recovery (tc))
1322 tcp_cc_recovery_exit (tc);
1323 else if (tcp_in_fastrecovery (tc))
1325 tcp_cc_recovered (tc);
1326 tcp_cc_fastrecovery_clear (tc);
1329 ASSERT (tc->rto_boff == 0);
1330 ASSERT (!tcp_in_cong_recovery (tc));
1331 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1336 tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1338 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1340 /* Congestion avoidance */
1341 tcp_cc_rcv_ack (tc, rs);
1343 /* If a cumulative ack, make sure dupacks is 0 */
1344 tc->rcv_dupacks = 0;
1346 /* When dupacks hits the threshold we only enter fast retransmit if
1347 * cumulative ack covers more than snd_congestion. Should snd_una
1348 * wrap this test may fail under otherwise valid circumstances.
1349 * Therefore, proactively update snd_congestion when wrap detected. */
1351 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1352 && seq_gt (tc->snd_congestion, tc->snd_una)))
1353 tc->snd_congestion = tc->snd_una - 1;
1357 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1359 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1363 tcp_should_fastrecover (tcp_connection_t * tc)
1365 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1366 || tcp_should_fastrecover_sack (tc));
1370 * One function to rule them all ... and in the darkness bind them
1373 tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs,
1376 u8 has_sack = tcp_opts_sack_permitted (&tc->rcv_opts);
1379 * Already in fast recovery. Return if no data acked, partial acks
1380 * and accounting for segments that have left the network are done
1383 if (tcp_in_fastrecovery (tc))
1388 if (!tc->bytes_acked)
1390 tcp_program_fastretransmit (tc);
1392 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1397 * In timer triggered recovery
1399 else if (tcp_in_recovery (tc))
1401 /* No fast recovery entry at this point */
1402 if (!tc->bytes_acked)
1406 * Duplicate ACK. Check if we should enter fast recovery
1410 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1411 ASSERT (tc->snd_una != tc->snd_nxt || tc->sack_sb.last_sacked_bytes);
1415 if (tcp_should_fastrecover (tc))
1419 ASSERT (!tcp_in_fastrecovery (tc));
1421 /* Heuristic to catch potential late dupacks
1422 * after fast retransmit exits */
1423 if (is_dack && tc->snd_una == tc->snd_congestion
1424 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1426 tc->rcv_dupacks = 0;
1430 tcp_cc_init_congestion (tc);
1433 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1435 /* Constrain rate until we get a partial ack */
1436 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1437 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1438 0 /* start bucket */ );
1439 tcp_program_fastretransmit (tc);
1444 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1448 /* Don't allow entry in fast recovery if still in recovery, for now */
1449 else if (0 && is_dack && tcp_in_recovery (tc))
1451 /* If of of the two conditions lower hold, reset dupacks because
1452 * we're probably after timeout (RFC6582 heuristics).
1453 * If Cumulative ack does not cover more than congestion threshold,
1455 * 1) The following doesn't hold: The congestion window is greater
1456 * than SMSS bytes and the difference between highest_ack
1457 * and prev_highest_ack is at most 4*SMSS bytes
1458 * 2) Echoed timestamp in the last non-dup ack does not equal the
1461 if (seq_leq (tc->snd_una, tc->snd_congestion)
1462 && ((!(tc->cwnd > tc->snd_mss
1463 && tc->bytes_acked <= 4 * tc->snd_mss))
1464 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1466 tc->rcv_dupacks = 0;
1471 ASSERT (tc->bytes_acked);
1472 TCP_EVT (TCP_EVT_CC_PACK, tc);
1475 * Legitimate ACK. 1) See if we can exit recovery
1478 if (seq_geq (tc->snd_una, tc->snd_congestion))
1480 /* If spurious return, we've already updated everything */
1481 if (tcp_cc_recover (tc))
1483 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1487 /* Treat as congestion avoidance ack */
1488 tcp_cc_rcv_ack (tc, rs);
1493 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1496 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1497 * reset dupacks to 0. Also needed if in congestion recovery */
1498 tc->rcv_dupacks = 0;
1500 /* Post RTO timeout don't try anything fancy */
1501 if (tcp_in_recovery (tc))
1503 tcp_cc_rcv_ack (tc, rs);
1504 transport_add_tx_event (&tc->connection);
1508 /* Remove retransmitted bytes that have been delivered */
1511 ASSERT (tc->bytes_acked >= tc->sack_sb.last_bytes_delivered
1512 || (tc->flags & TCP_CONN_FINSNT));
1514 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1515 * remove sacked bytes delivered */
1516 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1519 rxt_delivered = tc->bytes_acked - tc->sack_sb.last_bytes_delivered;
1520 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1521 tc->snd_rxt_bytes -= rxt_delivered;
1525 /* Apparently all retransmitted holes have been acked */
1526 tc->snd_rxt_bytes = 0;
1527 tc->sack_sb.high_rxt = tc->snd_una;
1532 tcp_fastrecovery_first_on (tc);
1533 if (tc->snd_rxt_bytes > tc->bytes_acked)
1534 tc->snd_rxt_bytes -= tc->bytes_acked;
1536 tc->snd_rxt_bytes = 0;
1539 tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs);
1542 * Since this was a partial ack, try to retransmit some more data
1544 tcp_program_fastretransmit (tc);
1548 * Process incoming ACK
1551 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1552 tcp_header_t * th, u32 * error)
1554 u32 prev_snd_wnd, prev_snd_una;
1555 tcp_rate_sample_t rs = { 0 };
1558 TCP_EVT (TCP_EVT_CC_STAT, tc);
1560 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1561 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1563 /* We've probably entered recovery and the peer still has some
1564 * of the data we've sent. Update snd_nxt and accept the ack */
1565 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1566 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1568 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1572 tc->errors.above_ack_wnd += 1;
1573 *error = TCP_ERROR_ACK_FUTURE;
1574 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 0, vnet_buffer (b)->tcp.ack_number);
1578 /* If old ACK, probably it's an old dupack */
1579 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1581 tc->errors.below_ack_wnd += 1;
1582 *error = TCP_ERROR_ACK_OLD;
1583 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 1, vnet_buffer (b)->tcp.ack_number);
1584 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1585 tcp_cc_handle_event (tc, 0, 1);
1586 /* Don't drop yet */
1593 * Looks okay, process feedback
1596 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1597 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1599 prev_snd_wnd = tc->snd_wnd;
1600 prev_snd_una = tc->snd_una;
1601 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1602 vnet_buffer (b)->tcp.ack_number,
1603 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1604 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1605 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
1606 tcp_validate_txf_size (tc, tc->bytes_acked);
1608 if (tc->flags & TCP_CONN_RATE_SAMPLE)
1609 tcp_bt_sample_delivery_rate (tc, &rs);
1611 if (tc->bytes_acked)
1613 tcp_program_dequeue (wrk, tc);
1614 tcp_update_rtt (tc, &rs, vnet_buffer (b)->tcp.ack_number);
1617 TCP_EVT (TCP_EVT_ACK_RCVD, tc);
1620 * Check if we have congestion event
1623 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1625 tcp_cc_handle_event (tc, &rs, is_dack);
1626 tc->dupacks_in += is_dack;
1627 if (!tcp_in_cong_recovery (tc))
1629 *error = TCP_ERROR_ACK_OK;
1632 *error = TCP_ERROR_ACK_DUP;
1633 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1639 * Update congestion control (slow start/congestion avoidance)
1641 tcp_cc_update (tc, &rs);
1642 *error = TCP_ERROR_ACK_OK;
1647 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1649 if (!tcp_disconnect_pending (tc))
1651 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1652 tcp_disconnect_pending_on (tc);
1657 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1659 u32 thread_index, *pending_disconnects;
1660 tcp_connection_t *tc;
1663 if (!vec_len (wrk->pending_disconnects))
1666 thread_index = wrk->vm->thread_index;
1667 pending_disconnects = wrk->pending_disconnects;
1668 for (i = 0; i < vec_len (pending_disconnects); i++)
1670 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1671 tcp_disconnect_pending_off (tc);
1672 session_transport_closing_notify (&tc->connection);
1674 _vec_len (wrk->pending_disconnects) = 0;
1678 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1681 /* Reject out-of-order fins */
1682 if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt)
1685 /* Account for the FIN and send ack */
1687 tcp_program_ack (tc);
1688 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1689 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1690 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1691 tcp_program_disconnect (wrk, tc);
1692 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
1693 TCP_EVT (TCP_EVT_FIN_RCVD, tc);
1694 *error = TCP_ERROR_FIN_RCVD;
1697 #ifndef CLIB_MARCH_VARIANT
1699 tcp_sack_vector_is_sane (sack_block_t * sacks)
1702 for (i = 1; i < vec_len (sacks); i++)
1704 if (sacks[i - 1].end == sacks[i].start)
1711 * Build SACK list as per RFC2018.
1713 * Makes sure the first block contains the segment that generated the current
1714 * ACK and the following ones are the ones most recently reported in SACK
1717 * @param tc TCP connection for which the SACK list is updated
1718 * @param start Start sequence number of the newest SACK block
1719 * @param end End sequence of the newest SACK block
1722 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1724 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1727 /* If the first segment is ooo add it to the list. Last write might've moved
1728 * rcv_nxt over the first segment. */
1729 if (seq_lt (tc->rcv_nxt, start))
1731 vec_add2 (new_list, block, 1);
1732 block->start = start;
1736 /* Find the blocks still worth keeping. */
1737 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1739 /* Discard if rcv_nxt advanced beyond current block */
1740 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1743 /* Merge or drop if segment overlapped by the new segment */
1744 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1745 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1747 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1748 new_list[0].start = tc->snd_sacks[i].start;
1749 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1750 new_list[0].end = tc->snd_sacks[i].end;
1754 /* Save to new SACK list if we have space. */
1755 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1756 vec_add1 (new_list, tc->snd_sacks[i]);
1759 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1761 /* Replace old vector with new one */
1762 vec_reset_length (tc->snd_sacks);
1763 tc->snd_sacks_fl = tc->snd_sacks;
1764 tc->snd_sacks = new_list;
1766 /* Segments should not 'touch' */
1767 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1771 tcp_sack_list_bytes (tcp_connection_t * tc)
1774 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1775 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1778 #endif /* CLIB_MARCH_VARIANT */
1780 /** Enqueue data for delivery to application */
1782 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1785 int written, error = TCP_ERROR_ENQUEUED;
1787 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1789 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1790 1 /* queue event */ , 1);
1791 tc->bytes_in += written;
1793 TCP_EVT (TCP_EVT_INPUT, tc, 0, data_len, written);
1795 /* Update rcv_nxt */
1796 if (PREDICT_TRUE (written == data_len))
1798 tc->rcv_nxt += written;
1800 /* If more data written than expected, account for out-of-order bytes. */
1801 else if (written > data_len)
1803 tc->rcv_nxt += written;
1804 TCP_EVT (TCP_EVT_CC_INPUT, tc, data_len, written);
1806 else if (written > 0)
1808 /* We've written something but FIFO is probably full now */
1809 tc->rcv_nxt += written;
1810 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1814 return TCP_ERROR_FIFO_FULL;
1817 /* Update SACK list if need be */
1818 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1820 /* Remove SACK blocks that have been delivered */
1821 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1827 /** Enqueue out-of-order data */
1829 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1835 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1838 /* Enqueue out-of-order data with relative offset */
1839 rv = session_enqueue_stream_connection (&tc->connection, b,
1840 vnet_buffer (b)->tcp.seq_number -
1841 tc->rcv_nxt, 0 /* queue event */ ,
1844 /* Nothing written */
1847 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, 0);
1848 return TCP_ERROR_FIFO_FULL;
1851 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1852 tc->bytes_in += data_len;
1854 /* Update SACK list if in use */
1855 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1857 ooo_segment_t *newest;
1860 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1862 /* Get the newest segment from the fifo */
1863 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1866 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1867 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1868 start = tc->rcv_nxt + offset;
1869 end = start + ooo_segment_length (s0->rx_fifo, newest);
1870 tcp_update_sack_list (tc, start, end);
1871 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1872 TCP_EVT (TCP_EVT_CC_SACKS, tc);
1876 return TCP_ERROR_ENQUEUED_OOO;
1880 * Check if ACK could be delayed. If ack can be delayed, it should return
1881 * true for a full frame. If we're always acking return 0.
1884 tcp_can_delack (tcp_connection_t * tc)
1886 /* Send ack if ... */
1888 /* just sent a rcv wnd 0
1889 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1890 /* constrained to send ack */
1891 || (tc->flags & TCP_CONN_SNDACK) != 0
1892 /* we're almost out of tx wnd */
1893 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1900 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1902 u32 discard, first = b->current_length;
1903 vlib_main_t *vm = vlib_get_main ();
1905 /* Handle multi-buffer segments */
1906 if (n_bytes_to_drop > b->current_length)
1908 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1912 discard = clib_min (n_bytes_to_drop, b->current_length);
1913 vlib_buffer_advance (b, discard);
1914 b = vlib_get_buffer (vm, b->next_buffer);
1915 n_bytes_to_drop -= discard;
1917 while (n_bytes_to_drop);
1918 if (n_bytes_to_drop > first)
1919 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1922 vlib_buffer_advance (b, n_bytes_to_drop);
1923 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1928 * Receive buffer for connection and handle acks
1930 * It handles both in order or out-of-order data.
1933 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1936 u32 error, n_bytes_to_drop, n_data_bytes;
1938 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1939 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1940 ASSERT (n_data_bytes);
1941 tc->data_segs_in += 1;
1943 /* Handle out-of-order data */
1944 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1946 /* Old sequence numbers allowed through because they overlapped
1948 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1950 /* Completely in the past (possible retransmit). Ack
1951 * retransmissions since we may not have any data to send */
1952 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1954 tcp_program_ack (tc);
1955 error = TCP_ERROR_SEGMENT_OLD;
1959 /* Chop off the bytes in the past and see if what is left
1960 * can be enqueued in order */
1961 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1962 n_data_bytes -= n_bytes_to_drop;
1963 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1964 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1966 error = TCP_ERROR_SEGMENT_OLD;
1972 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1973 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1974 tcp_program_dupack (tc);
1975 TCP_EVT (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1976 tc->errors.above_data_wnd += seq_gt (vnet_buffer (b)->tcp.seq_end,
1977 tc->rcv_las + tc->rcv_wnd);
1983 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1984 * segments can be enqueued after fifo tail offset changes. */
1985 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1986 if (tcp_can_delack (tc))
1988 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1989 tcp_timer_set (tc, TCP_TIMER_DELACK, tcp_cfg.delack_time);
1993 tcp_program_ack (tc);
2001 tcp_header_t tcp_header;
2002 tcp_connection_t tcp_connection;
2006 format_tcp_rx_trace (u8 * s, va_list * args)
2008 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2009 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2010 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2011 u32 indent = format_get_indent (s);
2013 s = format (s, "%U\n%U%U",
2014 format_tcp_header, &t->tcp_header, 128,
2015 format_white_space, indent,
2016 format_tcp_connection, &t->tcp_connection, 1);
2022 format_tcp_rx_trace_short (u8 * s, va_list * args)
2024 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2025 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2026 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2028 s = format (s, "%d -> %d (%U)",
2029 clib_net_to_host_u16 (t->tcp_header.dst_port),
2030 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2031 t->tcp_connection.state);
2037 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2038 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2042 clib_memcpy_fast (&t0->tcp_connection, tc0,
2043 sizeof (t0->tcp_connection));
2047 th0 = tcp_buffer_hdr (b0);
2049 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2053 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2054 vlib_frame_t * frame, u8 is_ip4)
2058 n_left = frame->n_vectors;
2059 from = vlib_frame_vector_args (frame);
2063 tcp_connection_t *tc0;
2070 b0 = vlib_get_buffer (vm, bi0);
2072 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2074 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2075 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2077 th0 = tcp_buffer_hdr (b0);
2078 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2087 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2088 u8 is_ip4, u32 evt, u32 val)
2091 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2093 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2096 #define tcp_maybe_inc_counter(node_id, err, count) \
2098 if (next0 != tcp_next_drop (is_ip4)) \
2099 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2100 tcp6_##node_id##_node.index, is_ip4, err, \
2103 #define tcp_inc_counter(node_id, err, count) \
2104 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2105 tcp6_##node_id##_node.index, is_ip4, \
2107 #define tcp_maybe_inc_err_counter(cnts, err) \
2109 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2111 #define tcp_inc_err_counter(cnts, err, val) \
2115 #define tcp_store_err_counters(node_id, cnts) \
2118 for (i = 0; i < TCP_N_ERROR; i++) \
2120 tcp_inc_counter(node_id, i, cnts[i]); \
2125 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2126 vlib_frame_t * frame, int is_ip4)
2128 u32 thread_index = vm->thread_index, errors = 0;
2129 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2130 u32 n_left_from, *from, *first_buffer;
2131 u16 err_counters[TCP_N_ERROR] = { 0 };
2133 if (node->flags & VLIB_NODE_FLAG_TRACE)
2134 tcp_established_trace_frame (vm, node, frame, is_ip4);
2136 first_buffer = from = vlib_frame_vector_args (frame);
2137 n_left_from = frame->n_vectors;
2139 while (n_left_from > 0)
2141 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2144 tcp_connection_t *tc0;
2146 if (n_left_from > 1)
2149 pb = vlib_get_buffer (vm, from[1]);
2150 vlib_prefetch_buffer_header (pb, LOAD);
2151 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2158 b0 = vlib_get_buffer (vm, bi0);
2159 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2162 if (PREDICT_FALSE (tc0 == 0))
2164 error0 = TCP_ERROR_INVALID_CONNECTION;
2168 th0 = tcp_buffer_hdr (b0);
2170 /* TODO header prediction fast path */
2172 /* 1-4: check SEQ, RST, SYN */
2173 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2175 TCP_EVT (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2179 /* 5: check the ACK field */
2180 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2183 /* 6: check the URG bit TODO */
2185 /* 7: process the segment text */
2186 if (vnet_buffer (b0)->tcp.data_len)
2187 error0 = tcp_segment_rcv (wrk, tc0, b0);
2189 /* 8: check the FIN bit */
2190 if (PREDICT_FALSE (tcp_is_fin (th0)))
2191 tcp_rcv_fin (wrk, tc0, b0, &error0);
2194 tcp_inc_err_counter (err_counters, error0, 1);
2197 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2199 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2200 tcp_store_err_counters (established, err_counters);
2201 tcp_handle_postponed_dequeues (wrk);
2202 tcp_handle_disconnects (wrk);
2203 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2205 return frame->n_vectors;
2208 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2209 vlib_node_runtime_t * node,
2210 vlib_frame_t * from_frame)
2212 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2215 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2216 vlib_node_runtime_t * node,
2217 vlib_frame_t * from_frame)
2219 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2223 VLIB_REGISTER_NODE (tcp4_established_node) =
2225 .name = "tcp4-established",
2226 /* Takes a vector of packets. */
2227 .vector_size = sizeof (u32),
2228 .n_errors = TCP_N_ERROR,
2229 .error_strings = tcp_error_strings,
2230 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2233 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2234 foreach_tcp_state_next
2237 .format_trace = format_tcp_rx_trace_short,
2242 VLIB_REGISTER_NODE (tcp6_established_node) =
2244 .name = "tcp6-established",
2245 /* Takes a vector of packets. */
2246 .vector_size = sizeof (u32),
2247 .n_errors = TCP_N_ERROR,
2248 .error_strings = tcp_error_strings,
2249 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2252 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2253 foreach_tcp_state_next
2256 .format_trace = format_tcp_rx_trace_short,
2262 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2264 transport_connection_t *tmp = 0;
2271 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2274 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2275 && (tc->state == TCP_STATE_LISTEN
2276 || tc->c_rmt_port == hdr->src_port));
2280 handle = session_lookup_half_open_handle (&tc->connection);
2281 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2282 tc->c_proto, tc->c_is_ip4);
2286 if (tmp->lcl_port == hdr->dst_port
2287 && tmp->rmt_port == hdr->src_port)
2289 TCP_DBG ("half-open is valid!");
2297 * Lookup transport connection
2299 static tcp_connection_t *
2300 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2304 transport_connection_t *tconn;
2305 tcp_connection_t *tc;
2310 ip4 = vlib_buffer_get_current (b);
2311 tcp = ip4_next_header (ip4);
2312 tconn = session_lookup_connection_wt4 (fib_index,
2317 TRANSPORT_PROTO_TCP,
2318 thread_index, &is_filtered);
2319 tc = tcp_get_connection_from_transport (tconn);
2320 ASSERT (tcp_lookup_is_valid (tc, tcp));
2325 ip6 = vlib_buffer_get_current (b);
2326 tcp = ip6_next_header (ip6);
2327 tconn = session_lookup_connection_wt6 (fib_index,
2332 TRANSPORT_PROTO_TCP,
2333 thread_index, &is_filtered);
2334 tc = tcp_get_connection_from_transport (tconn);
2335 ASSERT (tcp_lookup_is_valid (tc, tcp));
2341 tcp_check_tx_offload (tcp_connection_t * tc, int is_ipv4)
2343 vnet_main_t *vnm = vnet_get_main ();
2344 const dpo_id_t *dpo;
2345 const load_balance_t *lb;
2346 vnet_hw_interface_t *hw_if;
2347 u32 sw_if_idx, lb_idx;
2351 ip4_address_t *dst_addr = &(tc->c_rmt_ip.ip4);
2352 lb_idx = ip4_fib_forwarding_lookup (tc->c_fib_index, dst_addr);
2356 ip6_address_t *dst_addr = &(tc->c_rmt_ip.ip6);
2357 lb_idx = ip6_fib_table_fwding_lookup (tc->c_fib_index, dst_addr);
2360 lb = load_balance_get (lb_idx);
2361 dpo = load_balance_get_bucket_i (lb, 0);
2363 sw_if_idx = dpo->dpoi_index;
2364 hw_if = vnet_get_sup_hw_interface (vnm, sw_if_idx);
2367 ((hw_if->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO) == 0) ? 0 : 1;
2372 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2373 vlib_frame_t * from_frame, int is_ip4)
2375 u32 n_left_from, *from, *first_buffer, errors = 0;
2376 u32 my_thread_index = vm->thread_index;
2377 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2379 from = first_buffer = vlib_frame_vector_args (from_frame);
2380 n_left_from = from_frame->n_vectors;
2382 while (n_left_from > 0)
2384 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2385 tcp_connection_t *tc0, *new_tc0;
2386 tcp_header_t *tcp0 = 0;
2394 b0 = vlib_get_buffer (vm, bi0);
2396 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2397 if (PREDICT_FALSE (tc0 == 0))
2399 error0 = TCP_ERROR_INVALID_CONNECTION;
2403 /* Half-open completed recently but the connection was't removed
2404 * yet by the owning thread */
2405 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2407 /* Make sure the connection actually exists */
2408 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2409 my_thread_index, is_ip4));
2410 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2414 ack0 = vnet_buffer (b0)->tcp.ack_number;
2415 seq0 = vnet_buffer (b0)->tcp.seq_number;
2416 tcp0 = tcp_buffer_hdr (b0);
2418 /* Crude check to see if the connection handle does not match
2419 * the packet. Probably connection just switched to established */
2420 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2421 || tcp0->src_port != tc0->c_rmt_port))
2423 error0 = TCP_ERROR_INVALID_CONNECTION;
2427 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2428 && !tcp_syn (tcp0)))
2430 error0 = TCP_ERROR_SEGMENT_INVALID;
2434 /* SYNs consume sequence numbers */
2435 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2438 * 1. check the ACK bit
2442 * If the ACK bit is set
2443 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2444 * the RST bit is set, if so drop the segment and return)
2445 * <SEQ=SEG.ACK><CTL=RST>
2446 * and discard the segment. Return.
2447 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2451 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2453 if (!tcp_rst (tcp0))
2454 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2455 error0 = TCP_ERROR_RCV_WND;
2459 /* Make sure ACK is valid */
2460 if (seq_gt (tc0->snd_una, ack0))
2462 error0 = TCP_ERROR_ACK_INVALID;
2468 * 2. check the RST bit
2473 /* If ACK is acceptable, signal client that peer is not
2474 * willing to accept connection and drop connection*/
2476 tcp_connection_reset (tc0);
2477 error0 = TCP_ERROR_RST_RCVD;
2482 * 3. check the security and precedence (skipped)
2486 * 4. check the SYN bit
2489 /* No SYN flag. Drop. */
2490 if (!tcp_syn (tcp0))
2492 error0 = TCP_ERROR_SEGMENT_INVALID;
2497 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2499 error0 = TCP_ERROR_OPTIONS;
2503 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2504 * current thread pool. */
2505 new_tc0 = tcp_connection_alloc_w_base (my_thread_index, tc0);
2506 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2507 new_tc0->irs = seq0;
2508 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2509 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2511 /* If this is not the owning thread, wait for syn retransmit to
2512 * expire and cleanup then */
2513 if (tcp_half_open_connection_cleanup (tc0))
2514 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2516 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2518 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2519 new_tc0->tsval_recent_age = tcp_time_now ();
2522 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2523 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2525 new_tc0->rcv_wscale = 0;
2527 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2528 << new_tc0->snd_wscale;
2529 new_tc0->snd_wl1 = seq0;
2530 new_tc0->snd_wl2 = ack0;
2532 tcp_connection_init_vars (new_tc0);
2534 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2535 if (PREDICT_TRUE (tcp_ack (tcp0)))
2537 /* Our SYN is ACKed: we have iss < ack = snd_una */
2539 /* TODO Dequeue acknowledged segments if we support Fast Open */
2540 new_tc0->snd_una = ack0;
2541 new_tc0->state = TCP_STATE_ESTABLISHED;
2543 /* Make sure las is initialized for the wnd computation */
2544 new_tc0->rcv_las = new_tc0->rcv_nxt;
2546 /* Notify app that we have connection. If session layer can't
2547 * allocate session send reset */
2548 if (session_stream_connect_notify (&new_tc0->connection, 0))
2550 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2551 tcp_connection_cleanup (new_tc0);
2552 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2556 new_tc0->tx_fifo_size =
2557 transport_tx_fifo_size (&new_tc0->connection);
2558 /* Update rtt with the syn-ack sample */
2559 tcp_estimate_initial_rtt (new_tc0);
2560 TCP_EVT (TCP_EVT_SYNACK_RCVD, new_tc0);
2561 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2563 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2566 new_tc0->state = TCP_STATE_SYN_RCVD;
2568 /* Notify app that we have connection */
2569 if (session_stream_connect_notify (&new_tc0->connection, 0))
2571 tcp_connection_cleanup (new_tc0);
2572 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2573 TCP_EVT (TCP_EVT_RST_SENT, tc0);
2574 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2578 new_tc0->tx_fifo_size =
2579 transport_tx_fifo_size (&new_tc0->connection);
2580 new_tc0->rtt_ts = 0;
2581 tcp_init_snd_vars (new_tc0);
2582 tcp_send_synack (new_tc0);
2583 error0 = TCP_ERROR_SYNS_RCVD;
2587 tcp_check_tx_offload (new_tc0, is_ip4);
2589 /* Read data, if any */
2590 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2592 clib_warning ("rcvd data in syn-sent");
2593 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2594 if (error0 == TCP_ERROR_ACK_OK)
2595 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2599 tcp_program_ack (new_tc0);
2604 tcp_inc_counter (syn_sent, error0, 1);
2605 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2607 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2608 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2609 clib_memcpy_fast (&t0->tcp_connection, tc0,
2610 sizeof (t0->tcp_connection));
2614 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2616 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2617 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2619 return from_frame->n_vectors;
2622 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2623 vlib_node_runtime_t * node,
2624 vlib_frame_t * from_frame)
2626 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2629 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2630 vlib_node_runtime_t * node,
2631 vlib_frame_t * from_frame)
2633 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2637 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2639 .name = "tcp4-syn-sent",
2640 /* Takes a vector of packets. */
2641 .vector_size = sizeof (u32),
2642 .n_errors = TCP_N_ERROR,
2643 .error_strings = tcp_error_strings,
2644 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2647 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2648 foreach_tcp_state_next
2651 .format_trace = format_tcp_rx_trace_short,
2656 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2658 .name = "tcp6-syn-sent",
2659 /* Takes a vector of packets. */
2660 .vector_size = sizeof (u32),
2661 .n_errors = TCP_N_ERROR,
2662 .error_strings = tcp_error_strings,
2663 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2666 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2667 foreach_tcp_state_next
2670 .format_trace = format_tcp_rx_trace_short,
2675 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2676 * as per RFC793 p. 64
2679 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2680 vlib_frame_t * from_frame, int is_ip4)
2682 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2683 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2684 u32 n_left_from, *from, max_dequeue;
2686 from = first_buffer = vlib_frame_vector_args (from_frame);
2687 n_left_from = from_frame->n_vectors;
2689 while (n_left_from > 0)
2691 u32 bi0, error0 = TCP_ERROR_NONE;
2692 tcp_header_t *tcp0 = 0;
2693 tcp_connection_t *tc0;
2701 b0 = vlib_get_buffer (vm, bi0);
2702 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2704 if (PREDICT_FALSE (tc0 == 0))
2706 error0 = TCP_ERROR_INVALID_CONNECTION;
2710 tcp0 = tcp_buffer_hdr (b0);
2711 is_fin0 = tcp_is_fin (tcp0);
2715 tcp_connection_t *tmp;
2716 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2718 if (tmp->state != tc0->state)
2720 if (tc0->state != TCP_STATE_CLOSED)
2721 clib_warning ("state changed");
2727 * Special treatment for CLOSED
2729 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2731 error0 = TCP_ERROR_CONNECTION_CLOSED;
2736 * For all other states (except LISTEN)
2739 /* 1-4: check SEQ, RST, SYN */
2740 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2743 /* 5: check the ACK field */
2746 case TCP_STATE_SYN_RCVD:
2748 /* Make sure the segment is exactly right */
2749 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2751 tcp_connection_reset (tc0);
2752 error0 = TCP_ERROR_SEGMENT_INVALID;
2757 * If the segment acknowledgment is not acceptable, form a
2759 * <SEQ=SEG.ACK><CTL=RST>
2762 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2764 tcp_connection_reset (tc0);
2768 /* Update rtt and rto */
2769 tcp_estimate_initial_rtt (tc0);
2771 /* Switch state to ESTABLISHED */
2772 tc0->state = TCP_STATE_ESTABLISHED;
2773 TCP_EVT (TCP_EVT_STATE_CHANGE, tc0);
2775 tcp_check_tx_offload (tc0, is_ip4);
2777 /* Initialize session variables */
2778 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2779 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2780 << tc0->rcv_opts.wscale;
2781 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2782 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2784 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2785 tcp_retransmit_timer_reset (tc0);
2786 if (session_stream_accept_notify (&tc0->connection))
2788 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2789 tcp_connection_reset (tc0);
2792 error0 = TCP_ERROR_ACK_OK;
2794 case TCP_STATE_ESTABLISHED:
2795 /* We can get packets in established state here because they
2796 * were enqueued before state change */
2797 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2801 case TCP_STATE_FIN_WAIT_1:
2802 /* In addition to the processing for the ESTABLISHED state, if
2803 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2804 * continue processing in that state. */
2805 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2808 /* Still have to send the FIN */
2809 if (tc0->flags & TCP_CONN_FINPNDG)
2811 /* TX fifo finally drained */
2812 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2813 if (max_dequeue <= tc0->burst_acked)
2815 /* If a fin was received and data was acked extend wait */
2816 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
2817 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2818 tcp_cfg.closewait_time);
2820 /* If FIN is ACKed */
2821 else if (tc0->snd_una == tc0->snd_nxt)
2823 /* Stop all retransmit timers because we have nothing more
2825 tcp_connection_timers_reset (tc0);
2827 /* We already have a FIN but didn't transition to CLOSING
2828 * because of outstanding tx data. Close the connection. */
2829 if (tc0->flags & TCP_CONN_FINRCVD)
2831 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2832 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE,
2833 tcp_cfg.cleanup_time);
2834 session_transport_closed_notify (&tc0->connection);
2838 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2839 /* Enable waitclose because we're willing to wait for peer's
2840 * FIN but not indefinitely. */
2841 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait2_time);
2843 /* Don't try to deq the FIN acked */
2844 if (tc0->burst_acked > 1)
2845 session_tx_fifo_dequeue_drop (&tc0->connection,
2846 tc0->burst_acked - 1);
2847 tc0->burst_acked = 0;
2850 case TCP_STATE_FIN_WAIT_2:
2851 /* In addition to the processing for the ESTABLISHED state, if
2852 * the retransmission queue is empty, the user's CLOSE can be
2853 * acknowledged ("ok") but do not delete the TCB. */
2854 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2856 tc0->burst_acked = 0;
2858 case TCP_STATE_CLOSE_WAIT:
2859 /* Do the same processing as for the ESTABLISHED state. */
2860 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2863 if (!(tc0->flags & TCP_CONN_FINPNDG))
2866 /* Still have outstanding tx data */
2867 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2868 if (max_dequeue > tc0->burst_acked)
2872 tcp_connection_timers_reset (tc0);
2873 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2874 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2876 case TCP_STATE_CLOSING:
2877 /* In addition to the processing for the ESTABLISHED state, if
2878 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2879 * otherwise ignore the segment. */
2880 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2883 if (tc0->snd_una != tc0->snd_nxt)
2886 tcp_connection_timers_reset (tc0);
2887 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2888 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2889 session_transport_closed_notify (&tc0->connection);
2893 case TCP_STATE_LAST_ACK:
2894 /* The only thing that [should] arrive in this state is an
2895 * acknowledgment of our FIN. If our FIN is now acknowledged,
2896 * delete the TCB, enter the CLOSED state, and return. */
2898 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2901 /* Apparently our ACK for the peer's FIN was lost */
2902 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2908 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2909 session_transport_closed_notify (&tc0->connection);
2911 /* Don't free the connection from the data path since
2912 * we can't ensure that we have no packets already enqueued
2913 * to output. Rely instead on the waitclose timer */
2914 tcp_connection_timers_reset (tc0);
2915 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
2920 case TCP_STATE_TIME_WAIT:
2921 /* The only thing that can arrive in this state is a
2922 * retransmission of the remote FIN. Acknowledge it, and restart
2923 * the 2 MSL timeout. */
2925 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2931 tcp_program_ack (tc0);
2932 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2940 /* 6: check the URG bit TODO */
2942 /* 7: process the segment text */
2945 case TCP_STATE_ESTABLISHED:
2946 case TCP_STATE_FIN_WAIT_1:
2947 case TCP_STATE_FIN_WAIT_2:
2948 if (vnet_buffer (b0)->tcp.data_len)
2949 error0 = tcp_segment_rcv (wrk, tc0, b0);
2951 case TCP_STATE_CLOSE_WAIT:
2952 case TCP_STATE_CLOSING:
2953 case TCP_STATE_LAST_ACK:
2954 case TCP_STATE_TIME_WAIT:
2955 /* This should not occur, since a FIN has been received from the
2956 * remote side. Ignore the segment text. */
2960 /* 8: check the FIN bit */
2964 TCP_EVT (TCP_EVT_FIN_RCVD, tc0);
2968 case TCP_STATE_ESTABLISHED:
2969 /* Account for the FIN and send ack */
2971 tcp_program_ack (tc0);
2972 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2973 tcp_program_disconnect (wrk, tc0);
2974 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
2976 case TCP_STATE_SYN_RCVD:
2977 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2978 * notified yet, set a cleanup timer instead of relying on
2979 * disconnect notify and the implicit close call. */
2980 tcp_connection_timers_reset (tc0);
2983 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2984 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2986 case TCP_STATE_CLOSE_WAIT:
2987 case TCP_STATE_CLOSING:
2988 case TCP_STATE_LAST_ACK:
2991 case TCP_STATE_FIN_WAIT_1:
2994 if (tc0->flags & TCP_CONN_FINPNDG)
2996 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
2997 * sending it. Since we already received a fin, do not wait
2999 tc0->flags |= TCP_CONN_FINRCVD;
3000 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
3001 tcp_cfg.closewait_time);
3005 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
3006 tcp_program_ack (tc0);
3007 /* Wait for ACK for our FIN but not forever */
3008 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
3009 tcp_cfg.closing_time);
3012 case TCP_STATE_FIN_WAIT_2:
3013 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
3015 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
3016 tcp_connection_timers_reset (tc0);
3017 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3018 tcp_program_ack (tc0);
3019 session_transport_closed_notify (&tc0->connection);
3021 case TCP_STATE_TIME_WAIT:
3022 /* Remain in the TIME-WAIT state. Restart the time-wait
3025 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3028 error0 = TCP_ERROR_FIN_RCVD;
3032 tcp_inc_counter (rcv_process, error0, 1);
3033 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3035 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3036 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3040 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
3042 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3043 tcp_handle_postponed_dequeues (wrk);
3044 tcp_handle_disconnects (wrk);
3045 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3047 return from_frame->n_vectors;
3050 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
3051 vlib_node_runtime_t * node,
3052 vlib_frame_t * from_frame)
3054 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3057 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
3058 vlib_node_runtime_t * node,
3059 vlib_frame_t * from_frame)
3061 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3065 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3067 .name = "tcp4-rcv-process",
3068 /* Takes a vector of packets. */
3069 .vector_size = sizeof (u32),
3070 .n_errors = TCP_N_ERROR,
3071 .error_strings = tcp_error_strings,
3072 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3075 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3076 foreach_tcp_state_next
3079 .format_trace = format_tcp_rx_trace_short,
3084 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3086 .name = "tcp6-rcv-process",
3087 /* Takes a vector of packets. */
3088 .vector_size = sizeof (u32),
3089 .n_errors = TCP_N_ERROR,
3090 .error_strings = tcp_error_strings,
3091 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3094 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3095 foreach_tcp_state_next
3098 .format_trace = format_tcp_rx_trace_short,
3103 * LISTEN state processing as per RFC 793 p. 65
3106 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3107 vlib_frame_t * from_frame, int is_ip4)
3109 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3110 u32 my_thread_index = vm->thread_index;
3112 from = first_buffer = vlib_frame_vector_args (from_frame);
3113 n_left_from = from_frame->n_vectors;
3115 while (n_left_from > 0)
3120 tcp_header_t *th0 = 0;
3121 tcp_connection_t *lc0;
3124 tcp_connection_t *child0;
3125 u32 error0 = TCP_ERROR_NONE;
3131 b0 = vlib_get_buffer (vm, bi0);
3132 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3136 ip40 = vlib_buffer_get_current (b0);
3137 th0 = ip4_next_header (ip40);
3141 ip60 = vlib_buffer_get_current (b0);
3142 th0 = ip6_next_header (ip60);
3145 /* Create child session. For syn-flood protection use filter */
3147 /* 1. first check for an RST: handled in dispatch */
3148 /* if (tcp_rst (th0))
3152 /* 2. second check for an ACK: handled in dispatch */
3153 /* if (tcp_ack (th0))
3155 tcp_send_reset (b0, is_ip4);
3160 /* 3. check for a SYN (did that already) */
3162 /* Make sure connection wasn't just created */
3163 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3165 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3167 error0 = TCP_ERROR_CREATE_EXISTS;
3171 /* Create child session and send SYN-ACK */
3172 child0 = tcp_connection_alloc (my_thread_index);
3173 child0->c_lcl_port = th0->dst_port;
3174 child0->c_rmt_port = th0->src_port;
3175 child0->c_is_ip4 = is_ip4;
3176 child0->state = TCP_STATE_SYN_RCVD;
3177 child0->c_fib_index = lc0->c_fib_index;
3178 child0->cc_algo = lc0->cc_algo;
3182 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3183 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3187 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3188 sizeof (ip6_address_t));
3189 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3190 sizeof (ip6_address_t));
3193 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3195 error0 = TCP_ERROR_OPTIONS;
3196 tcp_connection_free (child0);
3200 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3201 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3202 child0->rcv_las = child0->rcv_nxt;
3203 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3205 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3206 * segments are used to initialize PAWS. */
3207 if (tcp_opts_tstamp (&child0->rcv_opts))
3209 child0->tsval_recent = child0->rcv_opts.tsval;
3210 child0->tsval_recent_age = tcp_time_now ();
3213 if (tcp_opts_wscale (&child0->rcv_opts))
3214 child0->snd_wscale = child0->rcv_opts.wscale;
3216 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3217 << child0->snd_wscale;
3218 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3219 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3221 tcp_connection_init_vars (child0);
3222 child0->rto = TCP_RTO_MIN;
3224 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3225 lc0->c_thread_index, 0 /* notify */ ))
3227 tcp_connection_cleanup (child0);
3228 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3232 TCP_EVT (TCP_EVT_SYN_RCVD, child0, 1);
3233 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3234 tcp_send_synack (child0);
3238 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3240 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3241 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3242 clib_memcpy_fast (&t0->tcp_connection, lc0,
3243 sizeof (t0->tcp_connection));
3246 n_syns += (error0 == TCP_ERROR_NONE);
3249 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3250 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3252 return from_frame->n_vectors;
3255 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3256 vlib_frame_t * from_frame)
3258 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3261 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3262 vlib_frame_t * from_frame)
3264 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3268 VLIB_REGISTER_NODE (tcp4_listen_node) =
3270 .name = "tcp4-listen",
3271 /* Takes a vector of packets. */
3272 .vector_size = sizeof (u32),
3273 .n_errors = TCP_N_ERROR,
3274 .error_strings = tcp_error_strings,
3275 .n_next_nodes = TCP_LISTEN_N_NEXT,
3278 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3279 foreach_tcp_state_next
3282 .format_trace = format_tcp_rx_trace_short,
3287 VLIB_REGISTER_NODE (tcp6_listen_node) =
3289 .name = "tcp6-listen",
3290 /* Takes a vector of packets. */
3291 .vector_size = sizeof (u32),
3292 .n_errors = TCP_N_ERROR,
3293 .error_strings = tcp_error_strings,
3294 .n_next_nodes = TCP_LISTEN_N_NEXT,
3297 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3298 foreach_tcp_state_next
3301 .format_trace = format_tcp_rx_trace_short,
3305 typedef enum _tcp_input_next
3307 TCP_INPUT_NEXT_DROP,
3308 TCP_INPUT_NEXT_LISTEN,
3309 TCP_INPUT_NEXT_RCV_PROCESS,
3310 TCP_INPUT_NEXT_SYN_SENT,
3311 TCP_INPUT_NEXT_ESTABLISHED,
3312 TCP_INPUT_NEXT_RESET,
3313 TCP_INPUT_NEXT_PUNT,
3317 #define foreach_tcp4_input_next \
3318 _ (DROP, "ip4-drop") \
3319 _ (LISTEN, "tcp4-listen") \
3320 _ (RCV_PROCESS, "tcp4-rcv-process") \
3321 _ (SYN_SENT, "tcp4-syn-sent") \
3322 _ (ESTABLISHED, "tcp4-established") \
3323 _ (RESET, "tcp4-reset") \
3324 _ (PUNT, "ip4-punt")
3326 #define foreach_tcp6_input_next \
3327 _ (DROP, "ip6-drop") \
3328 _ (LISTEN, "tcp6-listen") \
3329 _ (RCV_PROCESS, "tcp6-rcv-process") \
3330 _ (SYN_SENT, "tcp6-syn-sent") \
3331 _ (ESTABLISHED, "tcp6-established") \
3332 _ (RESET, "tcp6-reset") \
3333 _ (PUNT, "ip6-punt")
3335 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3338 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3339 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3341 tcp_connection_t *tc;
3346 for (i = 0; i < n_bufs; i++)
3348 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3350 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3351 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3353 tcp = vlib_buffer_get_current (bs[i]);
3354 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3360 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3362 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3364 *next = TCP_INPUT_NEXT_DROP;
3366 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3368 *next = TCP_INPUT_NEXT_PUNT;
3369 *error = TCP_ERROR_PUNT;
3373 *next = TCP_INPUT_NEXT_RESET;
3374 *error = TCP_ERROR_NO_LISTENER;
3378 always_inline tcp_connection_t *
3379 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3380 u8 is_ip4, u8 is_nolookup)
3382 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3383 int n_advance_bytes, n_data_bytes;
3384 transport_connection_t *tc;
3390 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3391 int ip_hdr_bytes = ip4_header_bytes (ip4);
3392 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3394 *error = TCP_ERROR_LENGTH;
3397 tcp = ip4_next_header (ip4);
3398 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3399 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3400 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3402 /* Length check. Checksum computed by ipx_local no need to compute again */
3403 if (PREDICT_FALSE (n_data_bytes < 0))
3405 *error = TCP_ERROR_LENGTH;
3410 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3411 &ip4->src_address, tcp->dst_port,
3413 TRANSPORT_PROTO_TCP, thread_index,
3418 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3419 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3421 *error = TCP_ERROR_LENGTH;
3424 tcp = ip6_next_header (ip6);
3425 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3426 n_advance_bytes = tcp_header_bytes (tcp);
3427 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3429 n_advance_bytes += sizeof (ip6[0]);
3431 if (PREDICT_FALSE (n_data_bytes < 0))
3433 *error = TCP_ERROR_LENGTH;
3440 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3442 ip4_main_t *im = &ip4_main;
3443 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3444 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3447 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3449 tcp->dst_port, tcp->src_port,
3450 TRANSPORT_PROTO_TCP,
3451 thread_index, &result);
3457 (transport_connection_t *) tcp_connection_get (vnet_buffer (b)->
3458 tcp.connection_index,
3461 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3462 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3463 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3464 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3465 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3467 vnet_buffer (b)->tcp.flags = 0;
3469 *error = result ? TCP_ERROR_NONE + result : *error;
3471 return tcp_get_connection_from_transport (tc);
3475 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3476 vlib_buffer_t * b, u16 * next, u32 * error)
3481 tcp = tcp_buffer_hdr (b);
3482 flags = tcp->flags & filter_flags;
3483 *next = tm->dispatch_table[tc->state][flags].next;
3484 *error = tm->dispatch_table[tc->state][flags].error;
3487 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3488 || *next == TCP_INPUT_NEXT_RESET))
3490 /* Overload tcp flags to store state */
3491 tcp_state_t state = tc->state;
3492 vnet_buffer (b)->tcp.flags = tc->state;
3494 if (*error == TCP_ERROR_DISPATCH)
3495 clib_warning ("tcp conn %u disp error state %U flags %U",
3496 tc->c_c_index, format_tcp_state, state,
3497 format_tcp_flags, (int) flags);
3502 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3503 vlib_frame_t * frame, int is_ip4, u8 is_nolookup)
3505 u32 n_left_from, *from, thread_index = vm->thread_index;
3506 tcp_main_t *tm = vnet_get_tcp_main ();
3507 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3508 u16 nexts[VLIB_FRAME_SIZE], *next;
3510 tcp_set_time_now (tcp_get_worker (thread_index));
3512 from = vlib_frame_vector_args (frame);
3513 n_left_from = frame->n_vectors;
3514 vlib_get_buffers (vm, from, bufs, n_left_from);
3519 while (n_left_from >= 4)
3521 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3522 tcp_connection_t *tc0, *tc1;
3525 vlib_prefetch_buffer_header (b[2], STORE);
3526 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3528 vlib_prefetch_buffer_header (b[3], STORE);
3529 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3532 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3534 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3536 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4,
3539 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3541 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3542 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3544 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3545 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3547 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3548 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3552 if (PREDICT_TRUE (tc0 != 0))
3554 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3555 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3556 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3559 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3561 if (PREDICT_TRUE (tc1 != 0))
3563 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3564 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3565 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3568 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3575 while (n_left_from > 0)
3577 tcp_connection_t *tc0;
3578 u32 error0 = TCP_ERROR_NO_LISTENER;
3580 if (n_left_from > 1)
3582 vlib_prefetch_buffer_header (b[1], STORE);
3583 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3586 next[0] = TCP_INPUT_NEXT_DROP;
3587 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3589 if (PREDICT_TRUE (tc0 != 0))
3591 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3592 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3593 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3596 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3603 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3604 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3606 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3607 return frame->n_vectors;
3610 VLIB_NODE_FN (tcp4_input_nolookup_node) (vlib_main_t * vm,
3611 vlib_node_runtime_t * node,
3612 vlib_frame_t * from_frame)
3614 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3615 1 /* is_nolookup */ );
3618 VLIB_NODE_FN (tcp6_input_nolookup_node) (vlib_main_t * vm,
3619 vlib_node_runtime_t * node,
3620 vlib_frame_t * from_frame)
3622 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3623 1 /* is_nolookup */ );
3627 VLIB_REGISTER_NODE (tcp4_input_nolookup_node) =
3629 .name = "tcp4-input-nolookup",
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_tcp4_input_next
3641 .format_buffer = format_tcp_header,
3642 .format_trace = format_tcp_rx_trace,
3647 VLIB_REGISTER_NODE (tcp6_input_nolookup_node) =
3649 .name = "tcp6-input-nolookup",
3650 /* Takes a vector of packets. */
3651 .vector_size = sizeof (u32),
3652 .n_errors = TCP_N_ERROR,
3653 .error_strings = tcp_error_strings,
3654 .n_next_nodes = TCP_INPUT_N_NEXT,
3657 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3658 foreach_tcp6_input_next
3661 .format_buffer = format_tcp_header,
3662 .format_trace = format_tcp_rx_trace,
3666 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3667 vlib_frame_t * from_frame)
3669 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3670 0 /* is_nolookup */ );
3673 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3674 vlib_frame_t * from_frame)
3676 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3677 0 /* is_nolookup */ );
3681 VLIB_REGISTER_NODE (tcp4_input_node) =
3683 .name = "tcp4-input",
3684 /* Takes a vector of packets. */
3685 .vector_size = sizeof (u32),
3686 .n_errors = TCP_N_ERROR,
3687 .error_strings = tcp_error_strings,
3688 .n_next_nodes = TCP_INPUT_N_NEXT,
3691 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3692 foreach_tcp4_input_next
3695 .format_buffer = format_tcp_header,
3696 .format_trace = format_tcp_rx_trace,
3701 VLIB_REGISTER_NODE (tcp6_input_node) =
3703 .name = "tcp6-input",
3704 /* Takes a vector of packets. */
3705 .vector_size = sizeof (u32),
3706 .n_errors = TCP_N_ERROR,
3707 .error_strings = tcp_error_strings,
3708 .n_next_nodes = TCP_INPUT_N_NEXT,
3711 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3712 foreach_tcp6_input_next
3715 .format_buffer = format_tcp_header,
3716 .format_trace = format_tcp_rx_trace,
3720 #ifndef CLIB_MARCH_VARIANT
3722 tcp_dispatch_table_init (tcp_main_t * tm)
3725 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3726 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3728 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3729 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3732 #define _(t,f,n,e) \
3734 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3735 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3738 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3739 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3740 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3741 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3742 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3743 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3744 TCP_ERROR_ACK_INVALID);
3745 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3746 TCP_ERROR_SEGMENT_INVALID);
3747 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3748 TCP_ERROR_SEGMENT_INVALID);
3749 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3750 TCP_ERROR_INVALID_CONNECTION);
3751 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3752 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3753 TCP_ERROR_SEGMENT_INVALID);
3754 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3755 TCP_ERROR_SEGMENT_INVALID);
3756 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3758 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3759 TCP_ERROR_SEGMENT_INVALID);
3760 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3761 TCP_ERROR_SEGMENT_INVALID);
3762 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3763 TCP_ERROR_SEGMENT_INVALID);
3764 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3765 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3766 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3767 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3768 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3769 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3771 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3772 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3774 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3776 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3777 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3778 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3779 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3781 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3783 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3784 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3785 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3787 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3788 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3789 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3790 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3791 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3792 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3793 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3794 /* SYN-ACK for a SYN */
3795 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3797 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3798 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3799 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3801 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3802 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3804 /* ACK for for established connection -> tcp-established. */
3805 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3806 /* FIN for for established connection -> tcp-established. */
3807 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3808 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3810 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3812 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3813 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3814 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3816 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3817 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3818 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3819 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3820 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3821 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3822 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3823 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3825 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3826 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3828 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3830 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3831 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3832 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3833 /* ACK or FIN-ACK to our FIN */
3834 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3835 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3837 /* FIN in reply to our FIN from the other side */
3838 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3839 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3840 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3842 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3843 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3844 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3845 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3846 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3847 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3848 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3850 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3851 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3852 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3853 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3855 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3857 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3858 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3859 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3860 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3862 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3863 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3864 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3865 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3867 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3869 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3870 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3871 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3872 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3874 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3875 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3877 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3879 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3880 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3881 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3883 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3884 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3885 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3886 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3887 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3888 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3889 /* FIN confirming that the peer (app) has closed */
3890 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3891 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3892 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3894 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3895 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3897 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3898 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3900 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3901 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3903 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3904 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3905 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3906 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3908 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3910 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3911 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3912 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3914 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3915 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3916 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3917 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3918 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3919 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3920 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3921 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3923 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3924 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3926 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3928 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3929 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3930 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3931 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3932 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3934 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3935 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3937 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3938 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3939 * incoming segment not containing a RST causes a RST to be sent in
3941 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3942 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3943 TCP_ERROR_CONNECTION_CLOSED);
3944 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3945 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3946 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3951 static clib_error_t *
3952 tcp_input_init (vlib_main_t * vm)
3954 clib_error_t *error = 0;
3955 tcp_main_t *tm = vnet_get_tcp_main ();
3957 if ((error = vlib_call_init_function (vm, tcp_init)))
3960 /* Initialize dispatch table. */
3961 tcp_dispatch_table_init (tm);
3966 VLIB_INIT_FUNCTION (tcp_input_init);
3968 #endif /* CLIB_MARCH_VARIANT */
3971 * fd.io coding-style-patch-verification: ON
3974 * eval: (c-set-style "gnu")