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 /* If not congested, update pacer based on our new
619 if (!tcp_in_fastrecovery (tc))
620 tcp_connection_tx_pacer_update (tc);
622 _vec_len (wrk->pending_deq_acked) = 0;
626 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
628 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
630 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
631 tc->flags |= TCP_CONN_DEQ_PENDING;
633 tc->burst_acked += tc->bytes_acked;
637 * Check if duplicate ack as per RFC5681 Sec. 2
640 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
643 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
644 && seq_gt (tc->snd_nxt, tc->snd_una)
645 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
646 && (prev_snd_wnd == tc->snd_wnd));
650 * Checks if ack is a congestion control event.
653 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
654 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
656 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
657 * defined to be 'duplicate' */
658 *is_dack = tc->sack_sb.last_sacked_bytes
659 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
661 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
664 #ifndef CLIB_MARCH_VARIANT
666 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
668 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
669 return hole - sb->holes;
673 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
675 return hole->end - hole->start;
678 sack_scoreboard_hole_t *
679 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
681 if (index != TCP_INVALID_SACK_HOLE_INDEX)
682 return pool_elt_at_index (sb->holes, index);
686 sack_scoreboard_hole_t *
687 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
689 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
690 return pool_elt_at_index (sb->holes, hole->next);
694 sack_scoreboard_hole_t *
695 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
697 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
698 return pool_elt_at_index (sb->holes, hole->prev);
702 sack_scoreboard_hole_t *
703 scoreboard_first_hole (sack_scoreboard_t * sb)
705 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
706 return pool_elt_at_index (sb->holes, sb->head);
710 sack_scoreboard_hole_t *
711 scoreboard_last_hole (sack_scoreboard_t * sb)
713 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
714 return pool_elt_at_index (sb->holes, sb->tail);
719 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
721 sack_scoreboard_hole_t *next, *prev;
723 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
725 next = pool_elt_at_index (sb->holes, hole->next);
726 next->prev = hole->prev;
730 sb->tail = hole->prev;
733 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
735 prev = pool_elt_at_index (sb->holes, hole->prev);
736 prev->next = hole->next;
740 sb->head = hole->next;
743 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
744 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
746 /* Poison the entry */
748 clib_memset (hole, 0xfe, sizeof (*hole));
750 pool_put (sb->holes, hole);
753 static sack_scoreboard_hole_t *
754 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
757 sack_scoreboard_hole_t *hole, *next, *prev;
760 pool_get (sb->holes, hole);
761 clib_memset (hole, 0, sizeof (*hole));
765 hole_index = scoreboard_hole_index (sb, hole);
767 prev = scoreboard_get_hole (sb, prev_index);
770 hole->prev = prev_index;
771 hole->next = prev->next;
773 if ((next = scoreboard_next_hole (sb, hole)))
774 next->prev = hole_index;
776 sb->tail = hole_index;
778 prev->next = hole_index;
782 sb->head = hole_index;
783 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
784 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
789 #endif /* CLIB_MARCH_VARIANT */
791 #ifndef CLIB_MARCH_VARIANT
794 scoreboard_update_bytes (sack_scoreboard_t * sb, u32 ack, u32 snd_mss)
796 sack_scoreboard_hole_t *left, *right;
797 u32 sacked = 0, blks = 0, old_sacked;
799 old_sacked = sb->sacked_bytes;
801 sb->last_lost_bytes = 0;
803 sb->sacked_bytes = 0;
805 right = scoreboard_last_hole (sb);
808 sb->sacked_bytes = sb->high_sacked - ack;
812 if (seq_gt (sb->high_sacked, right->end))
814 sacked = sb->high_sacked - right->end;
818 while (sacked < (TCP_DUPACK_THRESHOLD - 1) * snd_mss
819 && blks < TCP_DUPACK_THRESHOLD)
822 sb->lost_bytes += scoreboard_hole_bytes (right);
824 left = scoreboard_prev_hole (sb, right);
827 ASSERT (right->start == ack || sb->is_reneging);
828 sacked += right->start - ack;
833 sacked += right->start - left->end;
838 /* right is first lost */
841 sb->lost_bytes += scoreboard_hole_bytes (right);
842 sb->last_lost_bytes += right->is_lost ? 0 : right->end - right->start;
844 left = scoreboard_prev_hole (sb, right);
847 ASSERT (right->start == ack || sb->is_reneging);
848 sacked += right->start - ack;
851 sacked += right->start - left->end;
855 sb->sacked_bytes = sacked;
856 sb->last_sacked_bytes = sacked - (old_sacked - sb->last_bytes_delivered);
860 * Figure out the next hole to retransmit
862 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
864 sack_scoreboard_hole_t *
865 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
866 sack_scoreboard_hole_t * start,
867 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
869 sack_scoreboard_hole_t *hole = 0;
871 hole = start ? start : scoreboard_first_hole (sb);
872 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
873 hole = scoreboard_next_hole (sb, hole);
875 /* Nothing, return */
878 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
882 /* Rule (1): if higher than rxt, less than high_sacked and lost */
883 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
885 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
889 /* Rule (2): available unsent data */
892 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
895 /* Rule (3): if hole not lost */
896 else if (seq_lt (hole->start, sb->high_sacked))
899 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
901 /* Rule (4): if hole beyond high_sacked */
904 ASSERT (seq_geq (hole->start, sb->high_sacked));
907 /* HighRxt MUST NOT be updated */
912 if (hole && seq_lt (sb->high_rxt, hole->start))
913 sb->high_rxt = hole->start;
917 #endif /* CLIB_MARCH_VARIANT */
920 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
922 sack_scoreboard_hole_t *hole;
923 hole = scoreboard_first_hole (sb);
926 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
927 sb->cur_rxt_hole = sb->head;
929 sb->high_rxt = snd_una;
930 sb->rescue_rxt = snd_una - 1;
933 #ifndef CLIB_MARCH_VARIANT
935 scoreboard_init (sack_scoreboard_t * sb)
937 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
938 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
939 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
943 scoreboard_clear (sack_scoreboard_t * sb)
945 sack_scoreboard_hole_t *hole;
946 while ((hole = scoreboard_first_hole (sb)))
948 scoreboard_remove_hole (sb, hole);
950 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
951 ASSERT (pool_elts (sb->holes) == 0);
952 sb->sacked_bytes = 0;
953 sb->last_sacked_bytes = 0;
954 sb->last_bytes_delivered = 0;
958 sb->last_lost_bytes = 0;
959 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
962 #endif /* CLIB_MARCH_VARIANT */
965 * Test that scoreboard is sane after recovery
967 * Returns 1 if scoreboard is empty or if first hole beyond
971 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
973 sack_scoreboard_hole_t *hole;
974 hole = scoreboard_first_hole (&tc->sack_sb);
975 return (!hole || (seq_geq (hole->start, tc->snd_una)
976 && seq_lt (hole->end, tc->snd_nxt)));
979 #ifndef CLIB_MARCH_VARIANT
982 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
984 sack_scoreboard_hole_t *hole, *next_hole;
985 sack_scoreboard_t *sb = &tc->sack_sb;
986 sack_block_t *blk, *rcv_sacks;
987 u32 blk_index = 0, i, j;
989 sb->last_sacked_bytes = 0;
990 sb->last_bytes_delivered = 0;
992 if (!tcp_opts_sack (&tc->rcv_opts)
993 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
996 /* Remove invalid blocks */
997 blk = tc->rcv_opts.sacks;
998 while (blk < vec_end (tc->rcv_opts.sacks))
1000 if (seq_lt (blk->start, blk->end)
1001 && seq_gt (blk->start, tc->snd_una)
1002 && seq_gt (blk->start, ack)
1003 && seq_lt (blk->start, tc->snd_nxt)
1004 && seq_leq (blk->end, tc->snd_nxt))
1009 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
1012 /* Add block for cumulative ack */
1013 if (seq_gt (ack, tc->snd_una))
1015 vec_add2 (tc->rcv_opts.sacks, blk, 1);
1016 blk->start = tc->snd_una;
1020 if (vec_len (tc->rcv_opts.sacks) == 0)
1023 tcp_scoreboard_trace_add (tc, ack);
1025 /* Make sure blocks are ordered */
1026 rcv_sacks = tc->rcv_opts.sacks;
1027 for (i = 0; i < vec_len (rcv_sacks); i++)
1028 for (j = i + 1; j < vec_len (rcv_sacks); j++)
1029 if (seq_lt (rcv_sacks[j].start, rcv_sacks[i].start))
1031 sack_block_t tmp = rcv_sacks[i];
1032 rcv_sacks[i] = rcv_sacks[j];
1036 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1038 /* Handle reneging as a special case */
1039 if (PREDICT_FALSE (sb->is_reneging))
1041 /* No holes, only sacked bytes */
1042 if (seq_leq (tc->snd_nxt, sb->high_sacked))
1044 /* No progress made so return */
1045 if (seq_leq (ack, tc->snd_una))
1048 /* Update sacked bytes delivered and return */
1049 sb->last_bytes_delivered = ack - tc->snd_una;
1050 sb->sacked_bytes -= sb->last_bytes_delivered;
1051 sb->is_reneging = seq_lt (ack, sb->high_sacked);
1055 /* New hole above high sacked. Add it and process normally */
1056 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1057 sb->high_sacked, tc->snd_nxt);
1058 sb->tail = scoreboard_hole_index (sb, hole);
1060 /* Not reneging and no holes. Insert the first that covers all
1061 * outstanding bytes */
1064 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1065 tc->snd_una, tc->snd_nxt);
1066 sb->tail = scoreboard_hole_index (sb, hole);
1068 sb->high_sacked = rcv_sacks[vec_len (rcv_sacks) - 1].end;
1072 /* If we have holes but snd_nxt is beyond the last hole, update
1073 * last hole end or add new hole after high sacked */
1074 hole = scoreboard_last_hole (sb);
1075 if (seq_gt (tc->snd_nxt, hole->end))
1077 if (seq_geq (hole->start, sb->high_sacked))
1079 hole->end = tc->snd_nxt;
1081 /* New hole after high sacked block */
1082 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1084 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1089 /* Keep track of max byte sacked for when the last hole
1091 sb->high_sacked = seq_max (rcv_sacks[vec_len (rcv_sacks) - 1].end,
1095 /* Walk the holes with the SACK blocks */
1096 hole = pool_elt_at_index (sb->holes, sb->head);
1098 if (PREDICT_FALSE (sb->is_reneging))
1099 sb->last_bytes_delivered += hole->start - tc->snd_una;
1101 while (hole && blk_index < vec_len (rcv_sacks))
1103 blk = &rcv_sacks[blk_index];
1104 if (seq_leq (blk->start, hole->start))
1106 /* Block covers hole. Remove hole */
1107 if (seq_geq (blk->end, hole->end))
1109 next_hole = scoreboard_next_hole (sb, hole);
1111 /* If covered by ack, compute delivered bytes */
1112 if (blk->end == ack)
1114 u32 sacked = next_hole ? next_hole->start : sb->high_sacked;
1115 if (PREDICT_FALSE (seq_lt (ack, sacked)))
1117 sb->last_bytes_delivered += ack - hole->end;
1118 sb->is_reneging = 1;
1122 sb->last_bytes_delivered += sacked - hole->end;
1123 sb->is_reneging = 0;
1126 scoreboard_remove_hole (sb, hole);
1129 /* Partial 'head' overlap */
1132 if (seq_gt (blk->end, hole->start))
1134 hole->start = blk->end;
1141 /* Hole must be split */
1142 if (seq_lt (blk->end, hole->end))
1144 u32 hole_index = scoreboard_hole_index (sb, hole);
1145 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1147 /* Pool might've moved */
1148 hole = scoreboard_get_hole (sb, hole_index);
1149 hole->end = blk->start;
1151 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1153 else if (seq_lt (blk->start, hole->end))
1155 hole->end = blk->start;
1157 hole = scoreboard_next_hole (sb, hole);
1161 scoreboard_update_bytes (sb, ack, tc->snd_mss);
1163 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1164 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1165 || sb->sacked_bytes <= tc->snd_nxt - seq_max (tc->snd_una, ack));
1166 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1167 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1168 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1169 || sb->is_reneging || sb->holes[sb->head].start == ack);
1170 ASSERT (sb->last_lost_bytes <= sb->lost_bytes);
1172 TCP_EVT (TCP_EVT_CC_SCOREBOARD, tc);
1174 #endif /* CLIB_MARCH_VARIANT */
1177 * Try to update snd_wnd based on feedback received from peer.
1179 * If successful, and new window is 'effectively' 0, activate persist
1183 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1185 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1186 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1187 if (seq_lt (tc->snd_wl1, seq)
1188 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1190 tc->snd_wnd = snd_wnd;
1193 TCP_EVT (TCP_EVT_SND_WND, tc);
1195 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1197 /* Set persist timer if not set and we just got 0 wnd */
1198 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1199 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1200 tcp_persist_timer_set (tc);
1204 tcp_persist_timer_reset (tc);
1205 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1208 tcp_update_rto (tc);
1214 #ifndef CLIB_MARCH_VARIANT
1216 * Init loss recovery/fast recovery.
1218 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1219 * updated in @ref tcp_cc_handle_event after fast retransmit
1222 tcp_cc_init_congestion (tcp_connection_t * tc)
1224 tcp_fastrecovery_on (tc);
1225 tc->snd_congestion = tc->snd_nxt;
1226 tc->cwnd_acc_bytes = 0;
1227 tc->snd_rxt_bytes = 0;
1228 tc->prev_ssthresh = tc->ssthresh;
1229 tc->prev_cwnd = tc->cwnd;
1230 tc->cc_algo->congestion (tc);
1231 tc->fr_occurences += 1;
1232 TCP_EVT (TCP_EVT_CC_EVT, tc, 4);
1234 #endif /* CLIB_MARCH_VARIANT */
1237 tcp_cc_recovery_exit (tcp_connection_t * tc)
1240 tcp_update_rto (tc);
1243 tcp_recovery_off (tc);
1244 TCP_EVT (TCP_EVT_CC_EVT, tc, 3);
1247 #ifndef CLIB_MARCH_VARIANT
1249 tcp_cc_fastrecovery_clear (tcp_connection_t * tc)
1251 tc->snd_rxt_bytes = 0;
1252 tc->rcv_dupacks = 0;
1255 tcp_fastrecovery_off (tc);
1256 tcp_fastrecovery_first_off (tc);
1257 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1259 TCP_EVT (TCP_EVT_CC_EVT, tc, 3);
1261 #endif /* CLIB_MARCH_VARIANT */
1264 tcp_cc_congestion_undo (tcp_connection_t * tc)
1266 tc->cwnd = tc->prev_cwnd;
1267 tc->ssthresh = tc->prev_ssthresh;
1268 tc->rcv_dupacks = 0;
1269 if (tcp_in_recovery (tc))
1271 tcp_cc_recovery_exit (tc);
1272 tc->snd_nxt = seq_max (tc->snd_nxt, tc->snd_congestion);
1274 else if (tcp_in_fastrecovery (tc))
1276 tcp_cc_fastrecovery_clear (tc);
1278 tcp_cc_undo_recovery (tc);
1279 ASSERT (tc->rto_boff == 0);
1280 TCP_EVT (TCP_EVT_CC_EVT, tc, 5);
1284 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1286 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1288 && tcp_opts_tstamp (&tc->rcv_opts)
1289 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1293 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1295 return (tcp_in_fastrecovery (tc)
1296 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1300 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1302 return (tcp_cc_is_spurious_timeout_rxt (tc)
1303 || tcp_cc_is_spurious_fast_rxt (tc));
1307 tcp_cc_recover (tcp_connection_t * tc)
1309 sack_scoreboard_hole_t *hole;
1311 ASSERT (tcp_in_cong_recovery (tc));
1313 hole = scoreboard_first_hole (&tc->sack_sb);
1314 if (hole && hole->start == tc->snd_una && hole->end == tc->snd_nxt)
1315 scoreboard_clear (&tc->sack_sb);
1317 if (tcp_cc_is_spurious_retransmit (tc))
1319 tcp_cc_congestion_undo (tc);
1323 if (tcp_in_recovery (tc))
1324 tcp_cc_recovery_exit (tc);
1325 else if (tcp_in_fastrecovery (tc))
1327 tcp_cc_recovered (tc);
1328 tcp_cc_fastrecovery_clear (tc);
1331 ASSERT (tc->rto_boff == 0);
1332 ASSERT (!tcp_in_cong_recovery (tc));
1333 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1338 tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1340 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1342 /* Congestion avoidance */
1343 tcp_cc_rcv_ack (tc, rs);
1345 /* If a cumulative ack, make sure dupacks is 0 */
1346 tc->rcv_dupacks = 0;
1348 /* When dupacks hits the threshold we only enter fast retransmit if
1349 * cumulative ack covers more than snd_congestion. Should snd_una
1350 * wrap this test may fail under otherwise valid circumstances.
1351 * Therefore, proactively update snd_congestion when wrap detected. */
1353 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1354 && seq_gt (tc->snd_congestion, tc->snd_una)))
1355 tc->snd_congestion = tc->snd_una - 1;
1359 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1361 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1365 tcp_should_fastrecover (tcp_connection_t * tc)
1367 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1368 || tcp_should_fastrecover_sack (tc));
1372 * One function to rule them all ... and in the darkness bind them
1375 tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs,
1380 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1382 if (tc->bytes_acked)
1384 tcp_program_fastretransmit (tc);
1388 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1389 * it account for the bytes that left the network.
1391 else if (is_dack && !tcp_in_recovery (tc))
1393 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1394 ASSERT (tc->snd_una != tc->snd_nxt || tc->sack_sb.last_sacked_bytes);
1398 /* Pure duplicate ack. If some data got acked, it's handled lower */
1399 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1401 ASSERT (tcp_in_fastrecovery (tc));
1402 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1405 else if (tcp_should_fastrecover (tc))
1409 ASSERT (!tcp_in_fastrecovery (tc));
1411 /* Heuristic to catch potential late dupacks
1412 * after fast retransmit exits */
1413 if (is_dack && tc->snd_una == tc->snd_congestion
1414 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1416 tc->rcv_dupacks = 0;
1420 tcp_cc_init_congestion (tc);
1422 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1423 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1425 /* Constrain rate until we get a partial ack */
1426 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1427 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1428 0 /* start bucket */ );
1429 tcp_program_fastretransmit (tc);
1432 else if (!tc->bytes_acked
1433 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1435 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1441 /* Don't allow entry in fast recovery if still in recovery, for now */
1442 else if (0 && is_dack && tcp_in_recovery (tc))
1444 /* If of of the two conditions lower hold, reset dupacks because
1445 * we're probably after timeout (RFC6582 heuristics).
1446 * If Cumulative ack does not cover more than congestion threshold,
1448 * 1) The following doesn't hold: The congestion window is greater
1449 * than SMSS bytes and the difference between highest_ack
1450 * and prev_highest_ack is at most 4*SMSS bytes
1451 * 2) Echoed timestamp in the last non-dup ack does not equal the
1454 if (seq_leq (tc->snd_una, tc->snd_congestion)
1455 && ((!(tc->cwnd > tc->snd_mss
1456 && tc->bytes_acked <= 4 * tc->snd_mss))
1457 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1459 tc->rcv_dupacks = 0;
1464 if (!tc->bytes_acked)
1468 TCP_EVT (TCP_EVT_CC_PACK, tc);
1471 * Legitimate ACK. 1) See if we can exit recovery
1474 /* Update the pacing rate. For the first partial ack we move from
1475 * the artificially constrained rate to the one after congestion */
1476 tcp_connection_tx_pacer_update (tc);
1478 if (seq_geq (tc->snd_una, tc->snd_congestion))
1480 tcp_retransmit_timer_update (tc);
1482 /* If spurious return, we've already updated everything */
1483 if (tcp_cc_recover (tc))
1485 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1489 /* Treat as congestion avoidance ack */
1490 tcp_cc_rcv_ack (tc, rs);
1495 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1498 /* XXX limit this only to first partial ack? */
1499 tcp_retransmit_timer_update (tc);
1501 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1502 * reset dupacks to 0. Also needed if in congestion recovery */
1503 tc->rcv_dupacks = 0;
1505 /* Post RTO timeout don't try anything fancy */
1506 if (tcp_in_recovery (tc))
1508 tcp_cc_rcv_ack (tc, rs);
1509 transport_add_tx_event (&tc->connection);
1513 /* Remove retransmitted bytes that have been delivered */
1514 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1516 ASSERT (tc->bytes_acked >= tc->sack_sb.last_bytes_delivered
1517 || (tc->flags & TCP_CONN_FINSNT));
1519 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1520 * remove sacked bytes delivered */
1521 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1523 rxt_delivered = tc->bytes_acked - tc->sack_sb.last_bytes_delivered;
1524 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1525 tc->snd_rxt_bytes -= rxt_delivered;
1529 /* Apparently all retransmitted holes have been acked */
1530 tc->snd_rxt_bytes = 0;
1531 tc->sack_sb.high_rxt = tc->snd_una;
1536 tcp_fastrecovery_first_on (tc);
1537 if (tc->snd_rxt_bytes > tc->bytes_acked)
1538 tc->snd_rxt_bytes -= tc->bytes_acked;
1540 tc->snd_rxt_bytes = 0;
1543 tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs);
1546 * Since this was a partial ack, try to retransmit some more data
1548 tcp_program_fastretransmit (tc);
1552 * Process incoming ACK
1555 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1556 tcp_header_t * th, u32 * error)
1558 u32 prev_snd_wnd, prev_snd_una;
1559 tcp_rate_sample_t rs = { 0 };
1562 TCP_EVT (TCP_EVT_CC_STAT, tc);
1564 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1565 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1567 /* We've probably entered recovery and the peer still has some
1568 * of the data we've sent. Update snd_nxt and accept the ack */
1569 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1570 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1572 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1576 tc->errors.above_ack_wnd += 1;
1577 *error = TCP_ERROR_ACK_FUTURE;
1578 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 0, vnet_buffer (b)->tcp.ack_number);
1582 /* If old ACK, probably it's an old dupack */
1583 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1585 tc->errors.below_ack_wnd += 1;
1586 *error = TCP_ERROR_ACK_OLD;
1587 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 1, vnet_buffer (b)->tcp.ack_number);
1588 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1589 tcp_cc_handle_event (tc, 0, 1);
1590 /* Don't drop yet */
1597 * Looks okay, process feedback
1600 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1601 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1603 prev_snd_wnd = tc->snd_wnd;
1604 prev_snd_una = tc->snd_una;
1605 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1606 vnet_buffer (b)->tcp.ack_number,
1607 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1608 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1609 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
1610 tcp_validate_txf_size (tc, tc->bytes_acked);
1612 if (tc->flags & TCP_CONN_RATE_SAMPLE)
1613 tcp_bt_sample_delivery_rate (tc, &rs);
1615 if (tc->bytes_acked)
1617 tcp_program_dequeue (wrk, tc);
1618 tcp_update_rtt (tc, &rs, vnet_buffer (b)->tcp.ack_number);
1621 TCP_EVT (TCP_EVT_ACK_RCVD, tc);
1624 * Check if we have congestion event
1627 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1629 tcp_cc_handle_event (tc, &rs, is_dack);
1630 tc->dupacks_in += is_dack;
1631 if (!tcp_in_cong_recovery (tc))
1633 *error = TCP_ERROR_ACK_OK;
1636 *error = TCP_ERROR_ACK_DUP;
1637 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1643 * Update congestion control (slow start/congestion avoidance)
1645 tcp_cc_update (tc, &rs);
1646 *error = TCP_ERROR_ACK_OK;
1651 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1653 if (!tcp_disconnect_pending (tc))
1655 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1656 tcp_disconnect_pending_on (tc);
1661 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1663 u32 thread_index, *pending_disconnects;
1664 tcp_connection_t *tc;
1667 if (!vec_len (wrk->pending_disconnects))
1670 thread_index = wrk->vm->thread_index;
1671 pending_disconnects = wrk->pending_disconnects;
1672 for (i = 0; i < vec_len (pending_disconnects); i++)
1674 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1675 tcp_disconnect_pending_off (tc);
1676 session_transport_closing_notify (&tc->connection);
1678 _vec_len (wrk->pending_disconnects) = 0;
1682 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1685 /* Reject out-of-order fins */
1686 if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt)
1689 /* Account for the FIN and send ack */
1691 tcp_program_ack (tc);
1692 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1693 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1694 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1695 tcp_program_disconnect (wrk, tc);
1696 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
1697 TCP_EVT (TCP_EVT_FIN_RCVD, tc);
1698 *error = TCP_ERROR_FIN_RCVD;
1701 #ifndef CLIB_MARCH_VARIANT
1703 tcp_sack_vector_is_sane (sack_block_t * sacks)
1706 for (i = 1; i < vec_len (sacks); i++)
1708 if (sacks[i - 1].end == sacks[i].start)
1715 * Build SACK list as per RFC2018.
1717 * Makes sure the first block contains the segment that generated the current
1718 * ACK and the following ones are the ones most recently reported in SACK
1721 * @param tc TCP connection for which the SACK list is updated
1722 * @param start Start sequence number of the newest SACK block
1723 * @param end End sequence of the newest SACK block
1726 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1728 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1731 /* If the first segment is ooo add it to the list. Last write might've moved
1732 * rcv_nxt over the first segment. */
1733 if (seq_lt (tc->rcv_nxt, start))
1735 vec_add2 (new_list, block, 1);
1736 block->start = start;
1740 /* Find the blocks still worth keeping. */
1741 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1743 /* Discard if rcv_nxt advanced beyond current block */
1744 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1747 /* Merge or drop if segment overlapped by the new segment */
1748 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1749 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1751 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1752 new_list[0].start = tc->snd_sacks[i].start;
1753 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1754 new_list[0].end = tc->snd_sacks[i].end;
1758 /* Save to new SACK list if we have space. */
1759 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1760 vec_add1 (new_list, tc->snd_sacks[i]);
1763 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1765 /* Replace old vector with new one */
1766 vec_reset_length (tc->snd_sacks);
1767 tc->snd_sacks_fl = tc->snd_sacks;
1768 tc->snd_sacks = new_list;
1770 /* Segments should not 'touch' */
1771 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1775 tcp_sack_list_bytes (tcp_connection_t * tc)
1778 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1779 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1782 #endif /* CLIB_MARCH_VARIANT */
1784 /** Enqueue data for delivery to application */
1786 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1789 int written, error = TCP_ERROR_ENQUEUED;
1791 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1793 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1794 1 /* queue event */ , 1);
1795 tc->bytes_in += written;
1797 TCP_EVT (TCP_EVT_INPUT, tc, 0, data_len, written);
1799 /* Update rcv_nxt */
1800 if (PREDICT_TRUE (written == data_len))
1802 tc->rcv_nxt += written;
1804 /* If more data written than expected, account for out-of-order bytes. */
1805 else if (written > data_len)
1807 tc->rcv_nxt += written;
1808 TCP_EVT (TCP_EVT_CC_INPUT, tc, data_len, written);
1810 else if (written > 0)
1812 /* We've written something but FIFO is probably full now */
1813 tc->rcv_nxt += written;
1814 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1818 return TCP_ERROR_FIFO_FULL;
1821 /* Update SACK list if need be */
1822 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1824 /* Remove SACK blocks that have been delivered */
1825 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1831 /** Enqueue out-of-order data */
1833 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1839 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1842 /* Enqueue out-of-order data with relative offset */
1843 rv = session_enqueue_stream_connection (&tc->connection, b,
1844 vnet_buffer (b)->tcp.seq_number -
1845 tc->rcv_nxt, 0 /* queue event */ ,
1848 /* Nothing written */
1851 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, 0);
1852 return TCP_ERROR_FIFO_FULL;
1855 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1856 tc->bytes_in += data_len;
1858 /* Update SACK list if in use */
1859 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1861 ooo_segment_t *newest;
1864 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1866 /* Get the newest segment from the fifo */
1867 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1870 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1871 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1872 start = tc->rcv_nxt + offset;
1873 end = start + ooo_segment_length (s0->rx_fifo, newest);
1874 tcp_update_sack_list (tc, start, end);
1875 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1876 TCP_EVT (TCP_EVT_CC_SACKS, tc);
1880 return TCP_ERROR_ENQUEUED_OOO;
1884 * Check if ACK could be delayed. If ack can be delayed, it should return
1885 * true for a full frame. If we're always acking return 0.
1888 tcp_can_delack (tcp_connection_t * tc)
1890 /* Send ack if ... */
1892 /* just sent a rcv wnd 0
1893 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1894 /* constrained to send ack */
1895 || (tc->flags & TCP_CONN_SNDACK) != 0
1896 /* we're almost out of tx wnd */
1897 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1904 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1906 u32 discard, first = b->current_length;
1907 vlib_main_t *vm = vlib_get_main ();
1909 /* Handle multi-buffer segments */
1910 if (n_bytes_to_drop > b->current_length)
1912 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1916 discard = clib_min (n_bytes_to_drop, b->current_length);
1917 vlib_buffer_advance (b, discard);
1918 b = vlib_get_buffer (vm, b->next_buffer);
1919 n_bytes_to_drop -= discard;
1921 while (n_bytes_to_drop);
1922 if (n_bytes_to_drop > first)
1923 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1926 vlib_buffer_advance (b, n_bytes_to_drop);
1927 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1932 * Receive buffer for connection and handle acks
1934 * It handles both in order or out-of-order data.
1937 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1940 u32 error, n_bytes_to_drop, n_data_bytes;
1942 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1943 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1944 ASSERT (n_data_bytes);
1945 tc->data_segs_in += 1;
1947 /* Handle out-of-order data */
1948 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1950 /* Old sequence numbers allowed through because they overlapped
1952 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1954 /* Completely in the past (possible retransmit). Ack
1955 * retransmissions since we may not have any data to send */
1956 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1958 tcp_program_ack (tc);
1959 error = TCP_ERROR_SEGMENT_OLD;
1963 /* Chop off the bytes in the past and see if what is left
1964 * can be enqueued in order */
1965 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1966 n_data_bytes -= n_bytes_to_drop;
1967 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1968 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1970 error = TCP_ERROR_SEGMENT_OLD;
1976 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1977 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1978 tcp_program_dupack (tc);
1979 TCP_EVT (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1980 tc->errors.above_data_wnd += seq_gt (vnet_buffer (b)->tcp.seq_end,
1981 tc->rcv_las + tc->rcv_wnd);
1987 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1988 * segments can be enqueued after fifo tail offset changes. */
1989 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1990 if (tcp_can_delack (tc))
1992 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1993 tcp_timer_set (tc, TCP_TIMER_DELACK, tcp_cfg.delack_time);
1997 tcp_program_ack (tc);
2005 tcp_header_t tcp_header;
2006 tcp_connection_t tcp_connection;
2010 format_tcp_rx_trace (u8 * s, va_list * args)
2012 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2013 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2014 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2015 u32 indent = format_get_indent (s);
2017 s = format (s, "%U\n%U%U",
2018 format_tcp_header, &t->tcp_header, 128,
2019 format_white_space, indent,
2020 format_tcp_connection, &t->tcp_connection, 1);
2026 format_tcp_rx_trace_short (u8 * s, va_list * args)
2028 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2029 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2030 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2032 s = format (s, "%d -> %d (%U)",
2033 clib_net_to_host_u16 (t->tcp_header.dst_port),
2034 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2035 t->tcp_connection.state);
2041 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2042 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2046 clib_memcpy_fast (&t0->tcp_connection, tc0,
2047 sizeof (t0->tcp_connection));
2051 th0 = tcp_buffer_hdr (b0);
2053 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2057 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2058 vlib_frame_t * frame, u8 is_ip4)
2062 n_left = frame->n_vectors;
2063 from = vlib_frame_vector_args (frame);
2067 tcp_connection_t *tc0;
2074 b0 = vlib_get_buffer (vm, bi0);
2076 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2078 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2079 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2081 th0 = tcp_buffer_hdr (b0);
2082 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2091 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2092 u8 is_ip4, u32 evt, u32 val)
2095 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2097 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2100 #define tcp_maybe_inc_counter(node_id, err, count) \
2102 if (next0 != tcp_next_drop (is_ip4)) \
2103 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2104 tcp6_##node_id##_node.index, is_ip4, err, \
2107 #define tcp_inc_counter(node_id, err, count) \
2108 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2109 tcp6_##node_id##_node.index, is_ip4, \
2111 #define tcp_maybe_inc_err_counter(cnts, err) \
2113 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2115 #define tcp_inc_err_counter(cnts, err, val) \
2119 #define tcp_store_err_counters(node_id, cnts) \
2122 for (i = 0; i < TCP_N_ERROR; i++) \
2124 tcp_inc_counter(node_id, i, cnts[i]); \
2129 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2130 vlib_frame_t * frame, int is_ip4)
2132 u32 thread_index = vm->thread_index, errors = 0;
2133 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2134 u32 n_left_from, *from, *first_buffer;
2135 u16 err_counters[TCP_N_ERROR] = { 0 };
2137 if (node->flags & VLIB_NODE_FLAG_TRACE)
2138 tcp_established_trace_frame (vm, node, frame, is_ip4);
2140 first_buffer = from = vlib_frame_vector_args (frame);
2141 n_left_from = frame->n_vectors;
2143 while (n_left_from > 0)
2145 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2148 tcp_connection_t *tc0;
2150 if (n_left_from > 1)
2153 pb = vlib_get_buffer (vm, from[1]);
2154 vlib_prefetch_buffer_header (pb, LOAD);
2155 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2162 b0 = vlib_get_buffer (vm, bi0);
2163 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2166 if (PREDICT_FALSE (tc0 == 0))
2168 error0 = TCP_ERROR_INVALID_CONNECTION;
2172 th0 = tcp_buffer_hdr (b0);
2174 /* TODO header prediction fast path */
2176 /* 1-4: check SEQ, RST, SYN */
2177 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2179 TCP_EVT (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2183 /* 5: check the ACK field */
2184 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2187 /* 6: check the URG bit TODO */
2189 /* 7: process the segment text */
2190 if (vnet_buffer (b0)->tcp.data_len)
2191 error0 = tcp_segment_rcv (wrk, tc0, b0);
2193 /* 8: check the FIN bit */
2194 if (PREDICT_FALSE (tcp_is_fin (th0)))
2195 tcp_rcv_fin (wrk, tc0, b0, &error0);
2198 tcp_inc_err_counter (err_counters, error0, 1);
2201 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2203 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2204 tcp_store_err_counters (established, err_counters);
2205 tcp_handle_postponed_dequeues (wrk);
2206 tcp_handle_disconnects (wrk);
2207 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2209 return frame->n_vectors;
2212 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2213 vlib_node_runtime_t * node,
2214 vlib_frame_t * from_frame)
2216 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2219 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2220 vlib_node_runtime_t * node,
2221 vlib_frame_t * from_frame)
2223 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2227 VLIB_REGISTER_NODE (tcp4_established_node) =
2229 .name = "tcp4-established",
2230 /* Takes a vector of packets. */
2231 .vector_size = sizeof (u32),
2232 .n_errors = TCP_N_ERROR,
2233 .error_strings = tcp_error_strings,
2234 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2237 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2238 foreach_tcp_state_next
2241 .format_trace = format_tcp_rx_trace_short,
2246 VLIB_REGISTER_NODE (tcp6_established_node) =
2248 .name = "tcp6-established",
2249 /* Takes a vector of packets. */
2250 .vector_size = sizeof (u32),
2251 .n_errors = TCP_N_ERROR,
2252 .error_strings = tcp_error_strings,
2253 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2256 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2257 foreach_tcp_state_next
2260 .format_trace = format_tcp_rx_trace_short,
2266 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2268 transport_connection_t *tmp = 0;
2275 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2278 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2279 && (tc->state == TCP_STATE_LISTEN
2280 || tc->c_rmt_port == hdr->src_port));
2284 handle = session_lookup_half_open_handle (&tc->connection);
2285 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2286 tc->c_proto, tc->c_is_ip4);
2290 if (tmp->lcl_port == hdr->dst_port
2291 && tmp->rmt_port == hdr->src_port)
2293 TCP_DBG ("half-open is valid!");
2301 * Lookup transport connection
2303 static tcp_connection_t *
2304 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2308 transport_connection_t *tconn;
2309 tcp_connection_t *tc;
2314 ip4 = vlib_buffer_get_current (b);
2315 tcp = ip4_next_header (ip4);
2316 tconn = session_lookup_connection_wt4 (fib_index,
2321 TRANSPORT_PROTO_TCP,
2322 thread_index, &is_filtered);
2323 tc = tcp_get_connection_from_transport (tconn);
2324 ASSERT (tcp_lookup_is_valid (tc, tcp));
2329 ip6 = vlib_buffer_get_current (b);
2330 tcp = ip6_next_header (ip6);
2331 tconn = session_lookup_connection_wt6 (fib_index,
2336 TRANSPORT_PROTO_TCP,
2337 thread_index, &is_filtered);
2338 tc = tcp_get_connection_from_transport (tconn);
2339 ASSERT (tcp_lookup_is_valid (tc, tcp));
2345 tcp_check_tx_offload (tcp_connection_t * tc, int is_ipv4)
2347 vnet_main_t *vnm = vnet_get_main ();
2348 const dpo_id_t *dpo;
2349 const load_balance_t *lb;
2350 vnet_hw_interface_t *hw_if;
2351 u32 sw_if_idx, lb_idx;
2355 ip4_address_t *dst_addr = &(tc->c_rmt_ip.ip4);
2356 lb_idx = ip4_fib_forwarding_lookup (tc->c_fib_index, dst_addr);
2360 ip6_address_t *dst_addr = &(tc->c_rmt_ip.ip6);
2361 lb_idx = ip6_fib_table_fwding_lookup (tc->c_fib_index, dst_addr);
2364 lb = load_balance_get (lb_idx);
2365 dpo = load_balance_get_bucket_i (lb, 0);
2367 sw_if_idx = dpo->dpoi_index;
2368 hw_if = vnet_get_sup_hw_interface (vnm, sw_if_idx);
2371 ((hw_if->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO) == 0) ? 0 : 1;
2376 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2377 vlib_frame_t * from_frame, int is_ip4)
2379 u32 n_left_from, *from, *first_buffer, errors = 0;
2380 u32 my_thread_index = vm->thread_index;
2381 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2383 from = first_buffer = vlib_frame_vector_args (from_frame);
2384 n_left_from = from_frame->n_vectors;
2386 while (n_left_from > 0)
2388 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2389 tcp_connection_t *tc0, *new_tc0;
2390 tcp_header_t *tcp0 = 0;
2398 b0 = vlib_get_buffer (vm, bi0);
2400 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2401 if (PREDICT_FALSE (tc0 == 0))
2403 error0 = TCP_ERROR_INVALID_CONNECTION;
2407 /* Half-open completed recently but the connection was't removed
2408 * yet by the owning thread */
2409 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2411 /* Make sure the connection actually exists */
2412 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2413 my_thread_index, is_ip4));
2414 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2418 ack0 = vnet_buffer (b0)->tcp.ack_number;
2419 seq0 = vnet_buffer (b0)->tcp.seq_number;
2420 tcp0 = tcp_buffer_hdr (b0);
2422 /* Crude check to see if the connection handle does not match
2423 * the packet. Probably connection just switched to established */
2424 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2425 || tcp0->src_port != tc0->c_rmt_port))
2427 error0 = TCP_ERROR_INVALID_CONNECTION;
2431 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2432 && !tcp_syn (tcp0)))
2434 error0 = TCP_ERROR_SEGMENT_INVALID;
2438 /* SYNs consume sequence numbers */
2439 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2442 * 1. check the ACK bit
2446 * If the ACK bit is set
2447 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2448 * the RST bit is set, if so drop the segment and return)
2449 * <SEQ=SEG.ACK><CTL=RST>
2450 * and discard the segment. Return.
2451 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2455 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2457 if (!tcp_rst (tcp0))
2458 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2459 error0 = TCP_ERROR_RCV_WND;
2463 /* Make sure ACK is valid */
2464 if (seq_gt (tc0->snd_una, ack0))
2466 error0 = TCP_ERROR_ACK_INVALID;
2472 * 2. check the RST bit
2477 /* If ACK is acceptable, signal client that peer is not
2478 * willing to accept connection and drop connection*/
2480 tcp_connection_reset (tc0);
2481 error0 = TCP_ERROR_RST_RCVD;
2486 * 3. check the security and precedence (skipped)
2490 * 4. check the SYN bit
2493 /* No SYN flag. Drop. */
2494 if (!tcp_syn (tcp0))
2496 error0 = TCP_ERROR_SEGMENT_INVALID;
2501 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2503 error0 = TCP_ERROR_OPTIONS;
2507 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2508 * current thread pool. */
2509 new_tc0 = tcp_connection_alloc_w_base (my_thread_index, tc0);
2510 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2511 new_tc0->irs = seq0;
2512 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2513 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2515 /* If this is not the owning thread, wait for syn retransmit to
2516 * expire and cleanup then */
2517 if (tcp_half_open_connection_cleanup (tc0))
2518 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2520 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2522 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2523 new_tc0->tsval_recent_age = tcp_time_now ();
2526 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2527 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2529 new_tc0->rcv_wscale = 0;
2531 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2532 << new_tc0->snd_wscale;
2533 new_tc0->snd_wl1 = seq0;
2534 new_tc0->snd_wl2 = ack0;
2536 tcp_connection_init_vars (new_tc0);
2538 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2539 if (PREDICT_TRUE (tcp_ack (tcp0)))
2541 /* Our SYN is ACKed: we have iss < ack = snd_una */
2543 /* TODO Dequeue acknowledged segments if we support Fast Open */
2544 new_tc0->snd_una = ack0;
2545 new_tc0->state = TCP_STATE_ESTABLISHED;
2547 /* Make sure las is initialized for the wnd computation */
2548 new_tc0->rcv_las = new_tc0->rcv_nxt;
2550 /* Notify app that we have connection. If session layer can't
2551 * allocate session send reset */
2552 if (session_stream_connect_notify (&new_tc0->connection, 0))
2554 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2555 tcp_connection_cleanup (new_tc0);
2556 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2560 new_tc0->tx_fifo_size =
2561 transport_tx_fifo_size (&new_tc0->connection);
2562 /* Update rtt with the syn-ack sample */
2563 tcp_estimate_initial_rtt (new_tc0);
2564 TCP_EVT (TCP_EVT_SYNACK_RCVD, new_tc0);
2565 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2567 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2570 new_tc0->state = TCP_STATE_SYN_RCVD;
2572 /* Notify app that we have connection */
2573 if (session_stream_connect_notify (&new_tc0->connection, 0))
2575 tcp_connection_cleanup (new_tc0);
2576 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2577 TCP_EVT (TCP_EVT_RST_SENT, tc0);
2578 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2582 new_tc0->tx_fifo_size =
2583 transport_tx_fifo_size (&new_tc0->connection);
2584 new_tc0->rtt_ts = 0;
2585 tcp_init_snd_vars (new_tc0);
2586 tcp_send_synack (new_tc0);
2587 error0 = TCP_ERROR_SYNS_RCVD;
2591 tcp_check_tx_offload (new_tc0, is_ip4);
2593 /* Read data, if any */
2594 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2596 clib_warning ("rcvd data in syn-sent");
2597 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2598 if (error0 == TCP_ERROR_ACK_OK)
2599 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2603 tcp_program_ack (new_tc0);
2608 tcp_inc_counter (syn_sent, error0, 1);
2609 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2611 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2612 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2613 clib_memcpy_fast (&t0->tcp_connection, tc0,
2614 sizeof (t0->tcp_connection));
2618 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2620 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2621 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2623 return from_frame->n_vectors;
2626 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2627 vlib_node_runtime_t * node,
2628 vlib_frame_t * from_frame)
2630 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2633 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2634 vlib_node_runtime_t * node,
2635 vlib_frame_t * from_frame)
2637 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2641 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2643 .name = "tcp4-syn-sent",
2644 /* Takes a vector of packets. */
2645 .vector_size = sizeof (u32),
2646 .n_errors = TCP_N_ERROR,
2647 .error_strings = tcp_error_strings,
2648 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2651 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2652 foreach_tcp_state_next
2655 .format_trace = format_tcp_rx_trace_short,
2660 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2662 .name = "tcp6-syn-sent",
2663 /* Takes a vector of packets. */
2664 .vector_size = sizeof (u32),
2665 .n_errors = TCP_N_ERROR,
2666 .error_strings = tcp_error_strings,
2667 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2670 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2671 foreach_tcp_state_next
2674 .format_trace = format_tcp_rx_trace_short,
2679 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2680 * as per RFC793 p. 64
2683 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2684 vlib_frame_t * from_frame, int is_ip4)
2686 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2687 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2688 u32 n_left_from, *from, max_dequeue;
2690 from = first_buffer = vlib_frame_vector_args (from_frame);
2691 n_left_from = from_frame->n_vectors;
2693 while (n_left_from > 0)
2695 u32 bi0, error0 = TCP_ERROR_NONE;
2696 tcp_header_t *tcp0 = 0;
2697 tcp_connection_t *tc0;
2705 b0 = vlib_get_buffer (vm, bi0);
2706 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2708 if (PREDICT_FALSE (tc0 == 0))
2710 error0 = TCP_ERROR_INVALID_CONNECTION;
2714 tcp0 = tcp_buffer_hdr (b0);
2715 is_fin0 = tcp_is_fin (tcp0);
2719 tcp_connection_t *tmp;
2720 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2722 if (tmp->state != tc0->state)
2724 if (tc0->state != TCP_STATE_CLOSED)
2725 clib_warning ("state changed");
2731 * Special treatment for CLOSED
2733 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2735 error0 = TCP_ERROR_CONNECTION_CLOSED;
2740 * For all other states (except LISTEN)
2743 /* 1-4: check SEQ, RST, SYN */
2744 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2747 /* 5: check the ACK field */
2750 case TCP_STATE_SYN_RCVD:
2752 /* Make sure the segment is exactly right */
2753 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2755 tcp_connection_reset (tc0);
2756 error0 = TCP_ERROR_SEGMENT_INVALID;
2761 * If the segment acknowledgment is not acceptable, form a
2763 * <SEQ=SEG.ACK><CTL=RST>
2766 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2768 tcp_connection_reset (tc0);
2772 /* Update rtt and rto */
2773 tcp_estimate_initial_rtt (tc0);
2775 /* Switch state to ESTABLISHED */
2776 tc0->state = TCP_STATE_ESTABLISHED;
2777 TCP_EVT (TCP_EVT_STATE_CHANGE, tc0);
2779 tcp_check_tx_offload (tc0, is_ip4);
2781 /* Initialize session variables */
2782 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2783 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2784 << tc0->rcv_opts.wscale;
2785 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2786 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2788 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2789 tcp_retransmit_timer_reset (tc0);
2790 if (session_stream_accept_notify (&tc0->connection))
2792 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2793 tcp_connection_reset (tc0);
2796 error0 = TCP_ERROR_ACK_OK;
2798 case TCP_STATE_ESTABLISHED:
2799 /* We can get packets in established state here because they
2800 * were enqueued before state change */
2801 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2805 case TCP_STATE_FIN_WAIT_1:
2806 /* In addition to the processing for the ESTABLISHED state, if
2807 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2808 * continue processing in that state. */
2809 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2812 /* Still have to send the FIN */
2813 if (tc0->flags & TCP_CONN_FINPNDG)
2815 /* TX fifo finally drained */
2816 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2817 if (max_dequeue <= tc0->burst_acked)
2819 /* If a fin was received and data was acked extend wait */
2820 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
2821 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2822 tcp_cfg.closewait_time);
2824 /* If FIN is ACKed */
2825 else if (tc0->snd_una == tc0->snd_nxt)
2827 /* Stop all retransmit timers because we have nothing more
2829 tcp_connection_timers_reset (tc0);
2831 /* We already have a FIN but didn't transition to CLOSING
2832 * because of outstanding tx data. Close the connection. */
2833 if (tc0->flags & TCP_CONN_FINRCVD)
2835 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2836 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE,
2837 tcp_cfg.cleanup_time);
2838 session_transport_closed_notify (&tc0->connection);
2842 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2843 /* Enable waitclose because we're willing to wait for peer's
2844 * FIN but not indefinitely. */
2845 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait2_time);
2847 /* Don't try to deq the FIN acked */
2848 if (tc0->burst_acked > 1)
2849 session_tx_fifo_dequeue_drop (&tc0->connection,
2850 tc0->burst_acked - 1);
2851 tc0->burst_acked = 0;
2854 case TCP_STATE_FIN_WAIT_2:
2855 /* In addition to the processing for the ESTABLISHED state, if
2856 * the retransmission queue is empty, the user's CLOSE can be
2857 * acknowledged ("ok") but do not delete the TCB. */
2858 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2860 tc0->burst_acked = 0;
2862 case TCP_STATE_CLOSE_WAIT:
2863 /* Do the same processing as for the ESTABLISHED state. */
2864 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2867 if (!(tc0->flags & TCP_CONN_FINPNDG))
2870 /* Still have outstanding tx data */
2871 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2872 if (max_dequeue > tc0->burst_acked)
2876 tcp_connection_timers_reset (tc0);
2877 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2878 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2880 case TCP_STATE_CLOSING:
2881 /* In addition to the processing for the ESTABLISHED state, if
2882 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2883 * otherwise ignore the segment. */
2884 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2887 if (tc0->snd_una != tc0->snd_nxt)
2890 tcp_connection_timers_reset (tc0);
2891 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2892 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2893 session_transport_closed_notify (&tc0->connection);
2897 case TCP_STATE_LAST_ACK:
2898 /* The only thing that [should] arrive in this state is an
2899 * acknowledgment of our FIN. If our FIN is now acknowledged,
2900 * delete the TCB, enter the CLOSED state, and return. */
2902 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2905 /* Apparently our ACK for the peer's FIN was lost */
2906 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2912 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2913 session_transport_closed_notify (&tc0->connection);
2915 /* Don't free the connection from the data path since
2916 * we can't ensure that we have no packets already enqueued
2917 * to output. Rely instead on the waitclose timer */
2918 tcp_connection_timers_reset (tc0);
2919 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
2924 case TCP_STATE_TIME_WAIT:
2925 /* The only thing that can arrive in this state is a
2926 * retransmission of the remote FIN. Acknowledge it, and restart
2927 * the 2 MSL timeout. */
2929 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2935 tcp_program_ack (tc0);
2936 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2944 /* 6: check the URG bit TODO */
2946 /* 7: process the segment text */
2949 case TCP_STATE_ESTABLISHED:
2950 case TCP_STATE_FIN_WAIT_1:
2951 case TCP_STATE_FIN_WAIT_2:
2952 if (vnet_buffer (b0)->tcp.data_len)
2953 error0 = tcp_segment_rcv (wrk, tc0, b0);
2955 case TCP_STATE_CLOSE_WAIT:
2956 case TCP_STATE_CLOSING:
2957 case TCP_STATE_LAST_ACK:
2958 case TCP_STATE_TIME_WAIT:
2959 /* This should not occur, since a FIN has been received from the
2960 * remote side. Ignore the segment text. */
2964 /* 8: check the FIN bit */
2968 TCP_EVT (TCP_EVT_FIN_RCVD, tc0);
2972 case TCP_STATE_ESTABLISHED:
2973 /* Account for the FIN and send ack */
2975 tcp_program_ack (tc0);
2976 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2977 tcp_program_disconnect (wrk, tc0);
2978 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
2980 case TCP_STATE_SYN_RCVD:
2981 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2982 * notified yet, set a cleanup timer instead of relying on
2983 * disconnect notify and the implicit close call. */
2984 tcp_connection_timers_reset (tc0);
2987 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2988 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2990 case TCP_STATE_CLOSE_WAIT:
2991 case TCP_STATE_CLOSING:
2992 case TCP_STATE_LAST_ACK:
2995 case TCP_STATE_FIN_WAIT_1:
2998 if (tc0->flags & TCP_CONN_FINPNDG)
3000 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
3001 * sending it. Since we already received a fin, do not wait
3003 tc0->flags |= TCP_CONN_FINRCVD;
3004 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
3005 tcp_cfg.closewait_time);
3009 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
3010 tcp_program_ack (tc0);
3011 /* Wait for ACK for our FIN but not forever */
3012 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
3013 tcp_cfg.closing_time);
3016 case TCP_STATE_FIN_WAIT_2:
3017 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
3019 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
3020 tcp_connection_timers_reset (tc0);
3021 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3022 tcp_program_ack (tc0);
3023 session_transport_closed_notify (&tc0->connection);
3025 case TCP_STATE_TIME_WAIT:
3026 /* Remain in the TIME-WAIT state. Restart the time-wait
3029 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3032 error0 = TCP_ERROR_FIN_RCVD;
3036 tcp_inc_counter (rcv_process, error0, 1);
3037 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3039 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3040 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3044 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
3046 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3047 tcp_handle_postponed_dequeues (wrk);
3048 tcp_handle_disconnects (wrk);
3049 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3051 return from_frame->n_vectors;
3054 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
3055 vlib_node_runtime_t * node,
3056 vlib_frame_t * from_frame)
3058 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3061 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
3062 vlib_node_runtime_t * node,
3063 vlib_frame_t * from_frame)
3065 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3069 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3071 .name = "tcp4-rcv-process",
3072 /* Takes a vector of packets. */
3073 .vector_size = sizeof (u32),
3074 .n_errors = TCP_N_ERROR,
3075 .error_strings = tcp_error_strings,
3076 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3079 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3080 foreach_tcp_state_next
3083 .format_trace = format_tcp_rx_trace_short,
3088 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3090 .name = "tcp6-rcv-process",
3091 /* Takes a vector of packets. */
3092 .vector_size = sizeof (u32),
3093 .n_errors = TCP_N_ERROR,
3094 .error_strings = tcp_error_strings,
3095 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3098 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3099 foreach_tcp_state_next
3102 .format_trace = format_tcp_rx_trace_short,
3107 * LISTEN state processing as per RFC 793 p. 65
3110 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3111 vlib_frame_t * from_frame, int is_ip4)
3113 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3114 u32 my_thread_index = vm->thread_index;
3116 from = first_buffer = vlib_frame_vector_args (from_frame);
3117 n_left_from = from_frame->n_vectors;
3119 while (n_left_from > 0)
3124 tcp_header_t *th0 = 0;
3125 tcp_connection_t *lc0;
3128 tcp_connection_t *child0;
3129 u32 error0 = TCP_ERROR_NONE;
3135 b0 = vlib_get_buffer (vm, bi0);
3136 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3140 ip40 = vlib_buffer_get_current (b0);
3141 th0 = ip4_next_header (ip40);
3145 ip60 = vlib_buffer_get_current (b0);
3146 th0 = ip6_next_header (ip60);
3149 /* Create child session. For syn-flood protection use filter */
3151 /* 1. first check for an RST: handled in dispatch */
3152 /* if (tcp_rst (th0))
3156 /* 2. second check for an ACK: handled in dispatch */
3157 /* if (tcp_ack (th0))
3159 tcp_send_reset (b0, is_ip4);
3164 /* 3. check for a SYN (did that already) */
3166 /* Make sure connection wasn't just created */
3167 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3169 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3171 error0 = TCP_ERROR_CREATE_EXISTS;
3175 /* Create child session and send SYN-ACK */
3176 child0 = tcp_connection_alloc (my_thread_index);
3177 child0->c_lcl_port = th0->dst_port;
3178 child0->c_rmt_port = th0->src_port;
3179 child0->c_is_ip4 = is_ip4;
3180 child0->state = TCP_STATE_SYN_RCVD;
3181 child0->c_fib_index = lc0->c_fib_index;
3182 child0->cc_algo = lc0->cc_algo;
3186 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3187 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3191 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3192 sizeof (ip6_address_t));
3193 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3194 sizeof (ip6_address_t));
3197 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3199 error0 = TCP_ERROR_OPTIONS;
3200 tcp_connection_free (child0);
3204 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3205 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3206 child0->rcv_las = child0->rcv_nxt;
3207 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3209 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3210 * segments are used to initialize PAWS. */
3211 if (tcp_opts_tstamp (&child0->rcv_opts))
3213 child0->tsval_recent = child0->rcv_opts.tsval;
3214 child0->tsval_recent_age = tcp_time_now ();
3217 if (tcp_opts_wscale (&child0->rcv_opts))
3218 child0->snd_wscale = child0->rcv_opts.wscale;
3220 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3221 << child0->snd_wscale;
3222 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3223 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3225 tcp_connection_init_vars (child0);
3226 child0->rto = TCP_RTO_MIN;
3228 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3229 lc0->c_thread_index, 0 /* notify */ ))
3231 tcp_connection_cleanup (child0);
3232 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3236 TCP_EVT (TCP_EVT_SYN_RCVD, child0, 1);
3237 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3238 tcp_send_synack (child0);
3242 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3244 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3245 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3246 clib_memcpy_fast (&t0->tcp_connection, lc0,
3247 sizeof (t0->tcp_connection));
3250 n_syns += (error0 == TCP_ERROR_NONE);
3253 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3254 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3256 return from_frame->n_vectors;
3259 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3260 vlib_frame_t * from_frame)
3262 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3265 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3266 vlib_frame_t * from_frame)
3268 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3272 VLIB_REGISTER_NODE (tcp4_listen_node) =
3274 .name = "tcp4-listen",
3275 /* Takes a vector of packets. */
3276 .vector_size = sizeof (u32),
3277 .n_errors = TCP_N_ERROR,
3278 .error_strings = tcp_error_strings,
3279 .n_next_nodes = TCP_LISTEN_N_NEXT,
3282 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3283 foreach_tcp_state_next
3286 .format_trace = format_tcp_rx_trace_short,
3291 VLIB_REGISTER_NODE (tcp6_listen_node) =
3293 .name = "tcp6-listen",
3294 /* Takes a vector of packets. */
3295 .vector_size = sizeof (u32),
3296 .n_errors = TCP_N_ERROR,
3297 .error_strings = tcp_error_strings,
3298 .n_next_nodes = TCP_LISTEN_N_NEXT,
3301 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3302 foreach_tcp_state_next
3305 .format_trace = format_tcp_rx_trace_short,
3309 typedef enum _tcp_input_next
3311 TCP_INPUT_NEXT_DROP,
3312 TCP_INPUT_NEXT_LISTEN,
3313 TCP_INPUT_NEXT_RCV_PROCESS,
3314 TCP_INPUT_NEXT_SYN_SENT,
3315 TCP_INPUT_NEXT_ESTABLISHED,
3316 TCP_INPUT_NEXT_RESET,
3317 TCP_INPUT_NEXT_PUNT,
3321 #define foreach_tcp4_input_next \
3322 _ (DROP, "ip4-drop") \
3323 _ (LISTEN, "tcp4-listen") \
3324 _ (RCV_PROCESS, "tcp4-rcv-process") \
3325 _ (SYN_SENT, "tcp4-syn-sent") \
3326 _ (ESTABLISHED, "tcp4-established") \
3327 _ (RESET, "tcp4-reset") \
3328 _ (PUNT, "ip4-punt")
3330 #define foreach_tcp6_input_next \
3331 _ (DROP, "ip6-drop") \
3332 _ (LISTEN, "tcp6-listen") \
3333 _ (RCV_PROCESS, "tcp6-rcv-process") \
3334 _ (SYN_SENT, "tcp6-syn-sent") \
3335 _ (ESTABLISHED, "tcp6-established") \
3336 _ (RESET, "tcp6-reset") \
3337 _ (PUNT, "ip6-punt")
3339 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3342 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3343 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3345 tcp_connection_t *tc;
3350 for (i = 0; i < n_bufs; i++)
3352 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3354 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3355 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3357 tcp = vlib_buffer_get_current (bs[i]);
3358 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3364 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3366 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3368 *next = TCP_INPUT_NEXT_DROP;
3370 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3372 *next = TCP_INPUT_NEXT_PUNT;
3373 *error = TCP_ERROR_PUNT;
3377 *next = TCP_INPUT_NEXT_RESET;
3378 *error = TCP_ERROR_NO_LISTENER;
3382 always_inline tcp_connection_t *
3383 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3384 u8 is_ip4, u8 is_nolookup)
3386 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3387 int n_advance_bytes, n_data_bytes;
3388 transport_connection_t *tc;
3394 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3395 int ip_hdr_bytes = ip4_header_bytes (ip4);
3396 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3398 *error = TCP_ERROR_LENGTH;
3401 tcp = ip4_next_header (ip4);
3402 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3403 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3404 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3406 /* Length check. Checksum computed by ipx_local no need to compute again */
3407 if (PREDICT_FALSE (n_data_bytes < 0))
3409 *error = TCP_ERROR_LENGTH;
3414 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3415 &ip4->src_address, tcp->dst_port,
3417 TRANSPORT_PROTO_TCP, thread_index,
3422 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3423 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3425 *error = TCP_ERROR_LENGTH;
3428 tcp = ip6_next_header (ip6);
3429 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3430 n_advance_bytes = tcp_header_bytes (tcp);
3431 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3433 n_advance_bytes += sizeof (ip6[0]);
3435 if (PREDICT_FALSE (n_data_bytes < 0))
3437 *error = TCP_ERROR_LENGTH;
3444 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3446 ip4_main_t *im = &ip4_main;
3447 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3448 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3451 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3453 tcp->dst_port, tcp->src_port,
3454 TRANSPORT_PROTO_TCP,
3455 thread_index, &result);
3461 (transport_connection_t *) tcp_connection_get (vnet_buffer (b)->
3462 tcp.connection_index,
3465 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3466 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3467 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3468 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3469 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3471 vnet_buffer (b)->tcp.flags = 0;
3473 *error = result ? TCP_ERROR_NONE + result : *error;
3475 return tcp_get_connection_from_transport (tc);
3479 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3480 vlib_buffer_t * b, u16 * next, u32 * error)
3485 tcp = tcp_buffer_hdr (b);
3486 flags = tcp->flags & filter_flags;
3487 *next = tm->dispatch_table[tc->state][flags].next;
3488 *error = tm->dispatch_table[tc->state][flags].error;
3491 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3492 || *next == TCP_INPUT_NEXT_RESET))
3494 /* Overload tcp flags to store state */
3495 tcp_state_t state = tc->state;
3496 vnet_buffer (b)->tcp.flags = tc->state;
3498 if (*error == TCP_ERROR_DISPATCH)
3499 clib_warning ("tcp conn %u disp error state %U flags %U",
3500 tc->c_c_index, format_tcp_state, state,
3501 format_tcp_flags, (int) flags);
3506 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3507 vlib_frame_t * frame, int is_ip4, u8 is_nolookup)
3509 u32 n_left_from, *from, thread_index = vm->thread_index;
3510 tcp_main_t *tm = vnet_get_tcp_main ();
3511 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3512 u16 nexts[VLIB_FRAME_SIZE], *next;
3514 tcp_set_time_now (tcp_get_worker (thread_index));
3516 from = vlib_frame_vector_args (frame);
3517 n_left_from = frame->n_vectors;
3518 vlib_get_buffers (vm, from, bufs, n_left_from);
3523 while (n_left_from >= 4)
3525 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3526 tcp_connection_t *tc0, *tc1;
3529 vlib_prefetch_buffer_header (b[2], STORE);
3530 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3532 vlib_prefetch_buffer_header (b[3], STORE);
3533 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3536 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3538 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3540 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4,
3543 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3545 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3546 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3548 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3549 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3551 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3552 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3556 if (PREDICT_TRUE (tc0 != 0))
3558 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3559 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3560 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3563 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3565 if (PREDICT_TRUE (tc1 != 0))
3567 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3568 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3569 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3572 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3579 while (n_left_from > 0)
3581 tcp_connection_t *tc0;
3582 u32 error0 = TCP_ERROR_NO_LISTENER;
3584 if (n_left_from > 1)
3586 vlib_prefetch_buffer_header (b[1], STORE);
3587 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3590 next[0] = TCP_INPUT_NEXT_DROP;
3591 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3593 if (PREDICT_TRUE (tc0 != 0))
3595 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3596 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3597 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3600 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3607 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3608 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3610 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3611 return frame->n_vectors;
3614 VLIB_NODE_FN (tcp4_input_nolookup_node) (vlib_main_t * vm,
3615 vlib_node_runtime_t * node,
3616 vlib_frame_t * from_frame)
3618 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3619 1 /* is_nolookup */ );
3622 VLIB_NODE_FN (tcp6_input_nolookup_node) (vlib_main_t * vm,
3623 vlib_node_runtime_t * node,
3624 vlib_frame_t * from_frame)
3626 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3627 1 /* is_nolookup */ );
3631 VLIB_REGISTER_NODE (tcp4_input_nolookup_node) =
3633 .name = "tcp4-input-nolookup",
3634 /* Takes a vector of packets. */
3635 .vector_size = sizeof (u32),
3636 .n_errors = TCP_N_ERROR,
3637 .error_strings = tcp_error_strings,
3638 .n_next_nodes = TCP_INPUT_N_NEXT,
3641 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3642 foreach_tcp4_input_next
3645 .format_buffer = format_tcp_header,
3646 .format_trace = format_tcp_rx_trace,
3651 VLIB_REGISTER_NODE (tcp6_input_nolookup_node) =
3653 .name = "tcp6-input-nolookup",
3654 /* Takes a vector of packets. */
3655 .vector_size = sizeof (u32),
3656 .n_errors = TCP_N_ERROR,
3657 .error_strings = tcp_error_strings,
3658 .n_next_nodes = TCP_INPUT_N_NEXT,
3661 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3662 foreach_tcp6_input_next
3665 .format_buffer = format_tcp_header,
3666 .format_trace = format_tcp_rx_trace,
3670 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3671 vlib_frame_t * from_frame)
3673 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3674 0 /* is_nolookup */ );
3677 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3678 vlib_frame_t * from_frame)
3680 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3681 0 /* is_nolookup */ );
3685 VLIB_REGISTER_NODE (tcp4_input_node) =
3687 .name = "tcp4-input",
3688 /* Takes a vector of packets. */
3689 .vector_size = sizeof (u32),
3690 .n_errors = TCP_N_ERROR,
3691 .error_strings = tcp_error_strings,
3692 .n_next_nodes = TCP_INPUT_N_NEXT,
3695 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3696 foreach_tcp4_input_next
3699 .format_buffer = format_tcp_header,
3700 .format_trace = format_tcp_rx_trace,
3705 VLIB_REGISTER_NODE (tcp6_input_node) =
3707 .name = "tcp6-input",
3708 /* Takes a vector of packets. */
3709 .vector_size = sizeof (u32),
3710 .n_errors = TCP_N_ERROR,
3711 .error_strings = tcp_error_strings,
3712 .n_next_nodes = TCP_INPUT_N_NEXT,
3715 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3716 foreach_tcp6_input_next
3719 .format_buffer = format_tcp_header,
3720 .format_trace = format_tcp_rx_trace,
3724 #ifndef CLIB_MARCH_VARIANT
3726 tcp_dispatch_table_init (tcp_main_t * tm)
3729 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3730 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3732 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3733 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3736 #define _(t,f,n,e) \
3738 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3739 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3742 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3743 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3744 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3745 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3746 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3747 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3748 TCP_ERROR_ACK_INVALID);
3749 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3750 TCP_ERROR_SEGMENT_INVALID);
3751 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3752 TCP_ERROR_SEGMENT_INVALID);
3753 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3754 TCP_ERROR_INVALID_CONNECTION);
3755 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3756 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3757 TCP_ERROR_SEGMENT_INVALID);
3758 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3759 TCP_ERROR_SEGMENT_INVALID);
3760 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3762 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3763 TCP_ERROR_SEGMENT_INVALID);
3764 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3765 TCP_ERROR_SEGMENT_INVALID);
3766 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3767 TCP_ERROR_SEGMENT_INVALID);
3768 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3769 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3770 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3771 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3772 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3773 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3775 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3776 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3778 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3780 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3781 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3782 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3783 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3785 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3787 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3788 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3789 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3791 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3792 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3793 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3794 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3795 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3796 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3797 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3798 /* SYN-ACK for a SYN */
3799 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3801 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3802 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3803 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3805 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3806 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3808 /* ACK for for established connection -> tcp-established. */
3809 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3810 /* FIN for for established connection -> tcp-established. */
3811 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3812 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3814 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3816 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3817 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3818 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3820 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3821 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3822 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3823 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3824 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3825 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3826 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3827 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3829 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3830 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3832 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3834 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3835 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3836 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3837 /* ACK or FIN-ACK to our FIN */
3838 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3839 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3841 /* FIN in reply to our FIN from the other side */
3842 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3843 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3844 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3846 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3847 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3848 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3849 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3850 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3851 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3852 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3854 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3855 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3856 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3857 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3859 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3861 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3862 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3863 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3864 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3866 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3867 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3868 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3869 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3871 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3873 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3874 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3875 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3876 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3878 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3879 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3881 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3883 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3884 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3885 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3887 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3888 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3889 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3890 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3891 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3892 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3893 /* FIN confirming that the peer (app) has closed */
3894 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3895 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3896 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3898 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3899 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3901 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3902 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3904 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3905 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3907 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3908 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3909 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3910 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3912 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3914 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3915 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3916 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3918 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3919 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3920 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3921 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3922 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3923 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3924 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3925 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3927 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3928 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3930 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3932 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3933 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3934 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3935 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3936 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3938 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3939 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3941 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3942 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3943 * incoming segment not containing a RST causes a RST to be sent in
3945 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3946 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3947 TCP_ERROR_CONNECTION_CLOSED);
3948 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3949 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3950 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3955 static clib_error_t *
3956 tcp_input_init (vlib_main_t * vm)
3958 clib_error_t *error = 0;
3959 tcp_main_t *tm = vnet_get_tcp_main ();
3961 if ((error = vlib_call_init_function (vm, tcp_init)))
3964 /* Initialize dispatch table. */
3965 tcp_dispatch_table_init (tm);
3970 VLIB_INIT_FUNCTION (tcp_input_init);
3972 #endif /* CLIB_MARCH_VARIANT */
3975 * fd.io coding-style-patch-verification: ON
3978 * eval: (c-set-style "gnu")