2 * Copyright (c) 2016 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #include <vppinfra/sparse_vec.h>
17 #include <vnet/tcp/tcp_packet.h>
18 #include <vnet/tcp/tcp.h>
19 #include <vnet/session/session.h>
22 static char *tcp_error_strings[] = {
23 #define tcp_error(n,s) s,
24 #include <vnet/tcp/tcp_error.def>
28 /* All TCP nodes have the same outgoing arcs */
29 #define foreach_tcp_state_next \
30 _ (DROP4, "ip4-drop") \
31 _ (DROP6, "ip6-drop") \
32 _ (TCP4_OUTPUT, "tcp4-output") \
33 _ (TCP6_OUTPUT, "tcp6-output")
35 typedef enum _tcp_established_next
37 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
38 foreach_tcp_state_next
40 TCP_ESTABLISHED_N_NEXT,
41 } tcp_established_next_t;
43 typedef enum _tcp_rcv_process_next
45 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
46 foreach_tcp_state_next
48 TCP_RCV_PROCESS_N_NEXT,
49 } tcp_rcv_process_next_t;
51 typedef enum _tcp_syn_sent_next
53 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
54 foreach_tcp_state_next
57 } tcp_syn_sent_next_t;
59 typedef enum _tcp_listen_next
61 #define _(s,n) TCP_LISTEN_NEXT_##s,
62 foreach_tcp_state_next
67 /* Generic, state independent indices */
68 typedef enum _tcp_state_next
70 #define _(s,n) TCP_NEXT_##s,
71 foreach_tcp_state_next
76 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
77 : TCP_NEXT_TCP6_OUTPUT)
79 #define tcp_next_drop(is_ip4) (is_ip4 ? TCP_NEXT_DROP4 \
82 vlib_node_registration_t tcp4_established_node;
83 vlib_node_registration_t tcp6_established_node;
86 * Validate segment sequence number. As per RFC793:
88 * Segment Receive Test
90 * ------- ------- -------------------------------------------
91 * 0 0 SEG.SEQ = RCV.NXT
92 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
94 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
95 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
97 * This ultimately consists in checking if segment falls within the window.
98 * The one important difference compared to RFC793 is that we use rcv_las,
99 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
100 * peer's reference when computing our receive window.
103 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
104 * however, is too strict when we have retransmits. Instead we just check that
105 * the seq is not beyond the right edge and that the end of the segment is not
106 * less than the left edge.
108 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
109 * use rcv_nxt in the right edge window test instead of rcv_las.
113 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
115 return (seq_geq (end_seq, tc->rcv_las)
116 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
120 * Parse TCP header options.
122 * @param th TCP header
123 * @param to TCP options data structure to be populated
124 * @return -1 if parsing failed
127 tcp_options_parse (tcp_header_t * th, tcp_options_t * to)
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);
140 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
144 /* Get options length */
145 if (kind == TCP_OPTION_EOL)
147 else if (kind == TCP_OPTION_NOOP)
159 /* weird option length */
160 if (opt_len < 2 || opt_len > opts_len)
168 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
170 to->flags |= TCP_OPTS_FLAG_MSS;
171 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
174 case TCP_OPTION_WINDOW_SCALE:
175 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
177 to->flags |= TCP_OPTS_FLAG_WSCALE;
178 to->wscale = data[2];
179 if (to->wscale > TCP_MAX_WND_SCALE)
181 clib_warning ("Illegal window scaling value: %d",
183 to->wscale = TCP_MAX_WND_SCALE;
187 case TCP_OPTION_TIMESTAMP:
188 if (opt_len == TCP_OPTION_LEN_TIMESTAMP)
190 to->flags |= TCP_OPTS_FLAG_TSTAMP;
191 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
192 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
195 case TCP_OPTION_SACK_PERMITTED:
196 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
197 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
199 case TCP_OPTION_SACK_BLOCK:
200 /* If SACK permitted was not advertised or a SYN, break */
201 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
204 /* If too short or not correctly formatted, break */
205 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
208 to->flags |= TCP_OPTS_FLAG_SACK;
209 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
210 vec_reset_length (to->sacks);
211 for (j = 0; j < to->n_sack_blocks; j++)
213 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
214 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
215 vec_add1 (to->sacks, b);
219 /* Nothing to see here */
227 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
228 * timestamp to echo and it's less than tsval_recent, drop segment
229 * but still send an ACK in order to retain TCP's mechanism for detecting
230 * and recovering from half-open connections
232 * Or at least that's what the theory says. It seems that this might not work
233 * very well with packet reordering and fast retransmit. XXX
236 tcp_segment_check_paws (tcp_connection_t * tc)
238 return tcp_opts_tstamp (&tc->rcv_opts) && tc->tsval_recent
239 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
243 * Update tsval recent
246 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
249 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
250 * of an incoming segment:
251 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
252 * then the TSval from the segment is copied to TS.Recent;
253 * otherwise, the TSval is ignored.
255 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
256 && seq_leq (tc->rcv_las, seq_end))
258 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
259 tc->tsval_recent = tc->rcv_opts.tsval;
260 tc->tsval_recent_age = tcp_time_now ();
265 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
267 * It first verifies if segment has a wrapped sequence number (PAWS) and then
268 * does the processing associated to the first four steps (ignoring security
269 * and precedence): sequence number, rst bit and syn bit checks.
271 * @return 0 if segments passes validation.
274 tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0,
275 vlib_buffer_t * b0, tcp_header_t * th0,
276 u32 * next0, u32 * error0)
278 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
280 *error0 = TCP_ERROR_SEGMENT_INVALID;
284 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts)))
286 clib_warning ("options parse error");
287 *error0 = TCP_ERROR_OPTIONS;
291 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
293 *error0 = TCP_ERROR_PAWS;
296 clib_warning ("paws failed\n%U", format_tcp_connection, tc0, 2);
297 clib_warning ("seq %u seq_end %u ack %u",
298 vnet_buffer (b0)->tcp.seq_number - tc0->irs,
299 vnet_buffer (b0)->tcp.seq_end - tc0->irs,
300 vnet_buffer (b0)->tcp.ack_number - tc0->iss);
302 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
303 vnet_buffer (b0)->tcp.seq_end);
305 /* If it just so happens that a segment updates tsval_recent for a
306 * segment over 24 days old, invalidate tsval_recent. */
307 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
310 /* Age isn't reset until we get a valid tsval (bsd inspired) */
311 tc0->tsval_recent = 0;
312 clib_warning ("paws failed - really old segment. REALLY?");
316 /* Drop after ack if not rst */
319 tcp_make_ack (tc0, b0);
320 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
327 /* 1st: check sequence number */
328 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
329 vnet_buffer (b0)->tcp.seq_end))
331 *error0 = TCP_ERROR_RCV_WND;
333 /* If our window is 0 and the packet is in sequence, let it pass
334 * through for ack processing. It should be dropped later. */
335 if (!(tc0->rcv_wnd == 0
336 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number))
338 /* If not RST, send dup ack */
341 tcp_make_ack (tc0, b0);
342 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
349 /* 2nd: check the RST bit */
350 if (PREDICT_FALSE (tcp_rst (th0)))
352 tcp_connection_reset (tc0);
353 *error0 = TCP_ERROR_RST_RCVD;
357 /* 3rd: check security and precedence (skip) */
359 /* 4th: check the SYN bit */
360 if (PREDICT_FALSE (tcp_syn (th0)))
362 /* TODO implement RFC 5961 */
363 if (tc0->state == TCP_STATE_SYN_RCVD)
365 tcp_make_synack (tc0, b0);
366 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
370 tcp_make_ack (tc0, b0);
371 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
376 /* If segment in window, save timestamp */
377 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
378 vnet_buffer (b0)->tcp.seq_end);
382 *next0 = tcp_next_drop (tc0->c_is_ip4);
385 *next0 = tcp_next_output (tc0->c_is_ip4);
390 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
392 /* SND.UNA =< SEG.ACK =< SND.NXT */
393 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
394 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
398 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
400 * Note that although the original article, srtt and rttvar are scaled
401 * to minimize round-off errors, here we don't. Instead, we rely on
402 * better precision time measurements.
404 * TODO support us rtt resolution
407 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
413 err = mrtt - tc->srtt;
415 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
416 * The increase should be bound */
417 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
418 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
419 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
423 /* First measurement. */
425 tc->rttvar = mrtt >> 1;
430 tcp_update_rto (tcp_connection_t * tc)
432 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
433 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
437 * Update RTT estimate and RTO timer
439 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
440 * timing. Middle boxes are known to fiddle with TCP options so we
441 * should give higher priority to ACK timing.
443 * This should be called only if previously sent bytes have been acked.
445 * return 1 if valid rtt 0 otherwise
448 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
452 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
453 * RTT because they're ambiguous. */
454 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
457 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
459 mrtt = tcp_time_now () - tc->rtt_ts;
461 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
462 * snd_una, i.e., the left side of the send window:
463 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
464 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
466 mrtt = tcp_time_now () - tc->rcv_opts.tsecr;
469 /* Ignore dubious measurements */
470 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
473 tcp_estimate_rtt (tc, mrtt);
477 /* Allow measuring of a new RTT */
480 /* If we got here something must've been ACKed so make sure boff is 0,
481 * even if mrrt is not valid since we update the rto lower */
489 * Dequeue bytes that have been acked and while at it update RTT estimates.
492 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
494 /* Dequeue the newly ACKed add SACKed bytes */
495 stream_session_dequeue_drop (&tc->connection,
496 tc->bytes_acked + tc->sack_sb.snd_una_adv);
498 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
500 /* Update rtt and rto */
501 tcp_update_rtt (tc, ack);
503 /* If everything has been acked, stop retransmit timer
504 * otherwise update. */
505 tcp_retransmit_timer_update (tc);
509 * Check if duplicate ack as per RFC5681 Sec. 2
512 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
515 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
516 && seq_gt (tc->snd_una_max, tc->snd_una)
517 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
518 && (prev_snd_wnd == tc->snd_wnd));
522 * Checks if ack is a congestion control event.
525 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
526 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
528 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
529 * defined to be 'duplicate' */
530 *is_dack = tc->sack_sb.last_sacked_bytes
531 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
533 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
537 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
539 sack_scoreboard_hole_t *next, *prev;
541 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
543 next = pool_elt_at_index (sb->holes, hole->next);
544 next->prev = hole->prev;
548 sb->tail = hole->prev;
551 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
553 prev = pool_elt_at_index (sb->holes, hole->prev);
554 prev->next = hole->next;
558 sb->head = hole->next;
561 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
562 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
564 /* Poison the entry */
566 memset (hole, 0xfe, sizeof (*hole));
568 pool_put (sb->holes, hole);
571 sack_scoreboard_hole_t *
572 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
575 sack_scoreboard_hole_t *hole, *next, *prev;
578 pool_get (sb->holes, hole);
579 memset (hole, 0, sizeof (*hole));
583 hole_index = scoreboard_hole_index (sb, hole);
585 prev = scoreboard_get_hole (sb, prev_index);
588 hole->prev = prev_index;
589 hole->next = prev->next;
591 if ((next = scoreboard_next_hole (sb, hole)))
592 next->prev = hole_index;
594 sb->tail = hole_index;
596 prev->next = hole_index;
600 sb->head = hole_index;
601 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
602 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
609 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
611 sack_scoreboard_hole_t *hole, *prev;
612 u32 bytes = 0, blks = 0;
615 sb->sacked_bytes = 0;
616 hole = scoreboard_last_hole (sb);
620 if (seq_gt (sb->high_sacked, hole->end))
622 bytes = sb->high_sacked - hole->end;
626 while ((prev = scoreboard_prev_hole (sb, hole))
627 && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
628 && blks < TCP_DUPACK_THRESHOLD))
630 bytes += hole->start - prev->end;
637 sb->lost_bytes += scoreboard_hole_bytes (hole);
640 hole = scoreboard_prev_hole (sb, hole);
642 bytes += prev->start - hole->end;
644 sb->sacked_bytes = bytes;
648 * Figure out the next hole to retransmit
650 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
652 sack_scoreboard_hole_t *
653 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
654 sack_scoreboard_hole_t * start,
656 u8 * can_rescue, u8 * snd_limited)
658 sack_scoreboard_hole_t *hole = 0;
660 hole = start ? start : scoreboard_first_hole (sb);
661 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
662 hole = scoreboard_next_hole (sb, hole);
664 /* Nothing, return */
667 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
671 /* Rule (1): if higher than rxt, less than high_sacked and lost */
672 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
674 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
678 /* Rule (2): output takes care of transmitting new data */
679 if (!have_sent_1_smss)
682 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
684 /* Rule (3): if hole not lost */
685 else if (seq_lt (hole->start, sb->high_sacked))
688 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
690 /* Rule (4): if hole beyond high_sacked */
693 ASSERT (seq_geq (hole->start, sb->high_sacked));
696 /* HighRxt MUST NOT be updated */
701 if (hole && seq_lt (sb->high_rxt, hole->start))
702 sb->high_rxt = hole->start;
708 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
710 sack_scoreboard_hole_t *hole;
711 hole = scoreboard_first_hole (sb);
714 seq = seq_gt (seq, hole->start) ? seq : hole->start;
715 sb->cur_rxt_hole = sb->head;
721 * Test that scoreboard is sane after recovery
723 * Returns 1 if scoreboard is empty or if first hole beyond
727 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
729 sack_scoreboard_hole_t *hole;
730 hole = scoreboard_first_hole (&tc->sack_sb);
731 return (!hole || seq_geq (hole->start, tc->snd_una));
735 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
737 sack_scoreboard_t *sb = &tc->sack_sb;
738 sack_block_t *blk, tmp;
739 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
740 u32 blk_index = 0, old_sacked_bytes, hole_index;
743 sb->last_sacked_bytes = 0;
745 old_sacked_bytes = sb->sacked_bytes;
746 sb->last_bytes_delivered = 0;
748 if (!tcp_opts_sack (&tc->rcv_opts)
749 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
752 /* Remove invalid blocks */
753 blk = tc->rcv_opts.sacks;
754 while (blk < vec_end (tc->rcv_opts.sacks))
756 if (seq_lt (blk->start, blk->end)
757 && seq_gt (blk->start, tc->snd_una)
758 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
763 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
766 /* Add block for cumulative ack */
767 if (seq_gt (ack, tc->snd_una))
769 tmp.start = tc->snd_una;
771 vec_add1 (tc->rcv_opts.sacks, tmp);
774 if (vec_len (tc->rcv_opts.sacks) == 0)
777 tcp_scoreboard_trace_add (tc, ack);
779 /* Make sure blocks are ordered */
780 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
781 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
782 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
784 tmp = tc->rcv_opts.sacks[i];
785 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
786 tc->rcv_opts.sacks[j] = tmp;
789 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
791 /* If no holes, insert the first that covers all outstanding bytes */
792 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
793 tc->snd_una, tc->snd_una_max);
794 sb->tail = scoreboard_hole_index (sb, last_hole);
795 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
796 sb->high_sacked = tmp.end;
800 /* If we have holes but snd_una_max is beyond the last hole, update
802 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
803 last_hole = scoreboard_last_hole (sb);
804 if (seq_gt (tc->snd_una_max, last_hole->end))
806 if (seq_geq (last_hole->start, sb->high_sacked))
808 last_hole->end = tc->snd_una_max;
810 /* New hole after high sacked block */
811 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
813 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
817 /* Keep track of max byte sacked for when the last hole
819 if (seq_gt (tmp.end, sb->high_sacked))
820 sb->high_sacked = tmp.end;
823 /* Walk the holes with the SACK blocks */
824 hole = pool_elt_at_index (sb->holes, sb->head);
825 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
827 blk = &tc->rcv_opts.sacks[blk_index];
828 if (seq_leq (blk->start, hole->start))
830 /* Block covers hole. Remove hole */
831 if (seq_geq (blk->end, hole->end))
833 next_hole = scoreboard_next_hole (sb, hole);
835 /* Byte accounting: snd_una needs to be advanced */
840 if (seq_lt (ack, next_hole->start))
841 sb->snd_una_adv = next_hole->start - ack;
842 sb->last_bytes_delivered +=
843 next_hole->start - hole->end;
847 ASSERT (seq_geq (sb->high_sacked, ack));
848 sb->snd_una_adv = sb->high_sacked - ack;
849 sb->last_bytes_delivered += sb->high_sacked - hole->end;
853 scoreboard_remove_hole (sb, hole);
856 /* Partial 'head' overlap */
859 if (seq_gt (blk->end, hole->start))
861 hole->start = blk->end;
868 /* Hole must be split */
869 if (seq_lt (blk->end, hole->end))
871 hole_index = scoreboard_hole_index (sb, hole);
872 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
875 /* Pool might've moved */
876 hole = scoreboard_get_hole (sb, hole_index);
877 hole->end = blk->start;
879 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
881 else if (seq_lt (blk->start, hole->end))
883 hole->end = blk->start;
885 hole = scoreboard_next_hole (sb, hole);
889 scoreboard_update_bytes (tc, sb);
890 sb->last_sacked_bytes = sb->sacked_bytes
891 - (old_sacked_bytes - sb->last_bytes_delivered);
892 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes);
893 ASSERT (sb->sacked_bytes == 0
894 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
895 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
896 - seq_max (tc->snd_una, ack));
897 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
898 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
902 * Try to update snd_wnd based on feedback received from peer.
904 * If successful, and new window is 'effectively' 0, activate persist
908 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
910 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
911 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
912 if (seq_lt (tc->snd_wl1, seq)
913 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
915 tc->snd_wnd = snd_wnd;
918 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
920 if (tc->snd_wnd < tc->snd_mss)
922 /* Set persist timer if not set and we just got 0 wnd */
923 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
924 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
925 tcp_persist_timer_set (tc);
929 tcp_persist_timer_reset (tc);
930 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
940 * Init loss recovery/fast recovery.
942 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
943 * updated in @ref tcp_cc_handle_event after fast retransmit
946 tcp_cc_init_congestion (tcp_connection_t * tc)
948 tcp_fastrecovery_on (tc);
949 tc->snd_congestion = tc->snd_una_max;
950 tc->cwnd_acc_bytes = 0;
951 tc->cc_algo->congestion (tc);
952 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
956 tcp_cc_recovery_exit (tcp_connection_t * tc)
961 tc->snd_nxt = tc->snd_una_max;
962 tcp_recovery_off (tc);
963 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
967 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
969 tc->cc_algo->recovered (tc);
970 tc->snd_rxt_bytes = 0;
972 tc->snd_nxt = tc->snd_una_max;
973 tcp_fastrecovery_off (tc);
974 tcp_fastrecovery_1_smss_off (tc);
975 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
979 tcp_cc_congestion_undo (tcp_connection_t * tc)
981 tc->cwnd = tc->prev_cwnd;
982 tc->ssthresh = tc->prev_ssthresh;
983 tc->snd_nxt = tc->snd_una_max;
985 if (tcp_in_recovery (tc))
986 tcp_cc_recovery_exit (tc);
987 ASSERT (tc->rto_boff == 0);
988 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
989 /* TODO extend for fastrecovery */
993 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
995 return (tcp_in_recovery (tc) && tc->rto_boff == 1
997 && tcp_opts_tstamp (&tc->rcv_opts)
998 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1002 tcp_cc_recover (tcp_connection_t * tc)
1004 ASSERT (tcp_in_cong_recovery (tc));
1005 if (tcp_cc_is_spurious_retransmit (tc))
1007 clib_warning ("here");
1008 tcp_cc_congestion_undo (tc);
1012 if (tcp_in_recovery (tc))
1013 tcp_cc_recovery_exit (tc);
1014 else if (tcp_in_fastrecovery (tc))
1015 tcp_cc_fastrecovery_exit (tc);
1017 ASSERT (tc->rto_boff == 0);
1018 ASSERT (!tcp_in_cong_recovery (tc));
1019 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1024 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1026 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1028 /* Congestion avoidance */
1029 tc->cc_algo->rcv_ack (tc);
1030 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1032 /* If a cumulative ack, make sure dupacks is 0 */
1033 tc->rcv_dupacks = 0;
1035 /* When dupacks hits the threshold we only enter fast retransmit if
1036 * cumulative ack covers more than snd_congestion. Should snd_una
1037 * wrap this test may fail under otherwise valid circumstances.
1038 * Therefore, proactively update snd_congestion when wrap detected. */
1040 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1041 && seq_gt (tc->snd_congestion, tc->snd_una)))
1042 tc->snd_congestion = tc->snd_una - 1;
1046 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1048 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1052 tcp_should_fastrecover (tcp_connection_t * tc)
1054 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1055 || tcp_should_fastrecover_sack (tc));
1059 * One function to rule them all ... and in the darkness bind them
1062 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1067 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1068 * it account for the bytes that left the network.
1070 if (is_dack && !tcp_in_recovery (tc))
1072 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1073 ASSERT (tc->snd_una != tc->snd_una_max
1074 || tc->sack_sb.last_sacked_bytes);
1078 /* Pure duplicate ack. If some data got acked, it's handled lower */
1079 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1081 ASSERT (tcp_in_fastrecovery (tc));
1082 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1085 else if (tcp_should_fastrecover (tc))
1087 ASSERT (!tcp_in_fastrecovery (tc));
1089 /* If of of the two conditions lower hold, reset dupacks because
1090 * we're probably after timeout (RFC6582 heuristics).
1091 * If Cumulative ack does not cover more than congestion threshold,
1093 * 1) The following doesn't hold: The congestion window is greater
1094 * than SMSS bytes and the difference between highest_ack
1095 * and prev_highest_ack is at most 4*SMSS bytes
1096 * 2) Echoed timestamp in the last non-dup ack does not equal the
1099 if (seq_leq (tc->snd_una, tc->snd_congestion)
1100 && ((!(tc->cwnd > tc->snd_mss
1101 && tc->bytes_acked <= 4 * tc->snd_mss))
1102 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1104 tc->rcv_dupacks = 0;
1108 tcp_cc_init_congestion (tc);
1109 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1111 /* The first segment MUST be retransmitted */
1112 tcp_retransmit_first_unacked (tc);
1114 /* Post retransmit update cwnd to ssthresh and account for the
1115 * three segments that have left the network and should've been
1116 * buffered at the receiver XXX */
1117 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1118 ASSERT (tc->cwnd >= tc->snd_mss);
1120 /* If cwnd allows, send more data */
1121 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1123 scoreboard_init_high_rxt (&tc->sack_sb,
1124 tc->snd_una + tc->snd_mss);
1125 tcp_fast_retransmit_sack (tc);
1129 tcp_fast_retransmit_no_sack (tc);
1134 else if (!tc->bytes_acked
1135 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1137 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1144 if (!tc->bytes_acked)
1148 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1151 * Legitimate ACK. 1) See if we can exit recovery
1153 /* XXX limit this only to first partial ack? */
1154 tcp_retransmit_timer_update (tc);
1156 if (seq_geq (tc->snd_una, tc->snd_congestion))
1158 /* If spurious return, we've already updated everything */
1159 if (tcp_cc_recover (tc))
1161 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1165 tc->snd_nxt = tc->snd_una_max;
1167 /* Treat as congestion avoidance ack */
1168 tc->cc_algo->rcv_ack (tc);
1169 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1174 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1177 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1178 * reset dupacks to 0. Also needed if in congestion recovery */
1179 tc->rcv_dupacks = 0;
1181 /* Post RTO timeout don't try anything fancy */
1182 if (tcp_in_recovery (tc))
1184 tc->cc_algo->rcv_ack (tc);
1185 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1189 /* Remove retransmitted bytes that have been delivered */
1190 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1191 >= tc->sack_sb.last_bytes_delivered
1192 || (tc->flags & TCP_CONN_FINSNT));
1194 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1196 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1197 * remove sacked bytes delivered */
1198 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1199 - tc->sack_sb.last_bytes_delivered;
1200 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1201 tc->snd_rxt_bytes -= rxt_delivered;
1205 /* Either all retransmitted holes have been acked, or we're
1206 * "in the blind" and retransmitting segment by segment */
1207 tc->snd_rxt_bytes = 0;
1210 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1213 * Since this was a partial ack, try to retransmit some more data
1215 tcp_fast_retransmit (tc);
1219 tcp_cc_init (tcp_connection_t * tc)
1221 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
1222 tc->cc_algo->init (tc);
1226 * Process incoming ACK
1229 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1230 tcp_header_t * th, u32 * next, u32 * error)
1232 u32 prev_snd_wnd, prev_snd_una;
1235 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1237 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1238 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1240 /* If we have outstanding data and this is within the window, accept it,
1241 * probably retransmit has timed out. Otherwise ACK segment and then
1243 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1245 tcp_make_ack (tc, b);
1246 *next = tcp_next_output (tc->c_is_ip4);
1247 *error = TCP_ERROR_ACK_INVALID;
1248 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1249 vnet_buffer (b)->tcp.ack_number);
1253 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1254 vnet_buffer (b)->tcp.ack_number);
1256 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1257 *error = TCP_ERROR_ACK_FUTURE;
1260 /* If old ACK, probably it's an old dupack */
1261 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1263 *error = TCP_ERROR_ACK_OLD;
1264 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1265 vnet_buffer (b)->tcp.ack_number);
1266 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1268 tcp_cc_handle_event (tc, 1);
1270 /* Don't drop yet */
1275 * Looks okay, process feedback
1278 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1279 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1281 prev_snd_wnd = tc->snd_wnd;
1282 prev_snd_una = tc->snd_una;
1283 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1284 vnet_buffer (b)->tcp.ack_number,
1285 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1286 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1287 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1288 tcp_validate_txf_size (tc, tc->bytes_acked);
1290 if (tc->bytes_acked)
1291 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1293 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1296 * Check if we have congestion event
1299 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1301 tcp_cc_handle_event (tc, is_dack);
1302 if (!tcp_in_cong_recovery (tc))
1304 *error = TCP_ERROR_ACK_DUP;
1305 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1309 * Update congestion control (slow start/congestion avoidance)
1311 tcp_cc_update (tc, b);
1312 *error = TCP_ERROR_ACK_OK;
1317 tcp_sack_vector_is_sane (sack_block_t * sacks)
1320 for (i = 1; i < vec_len (sacks); i++)
1322 if (sacks[i - 1].end == sacks[i].start)
1329 * Build SACK list as per RFC2018.
1331 * Makes sure the first block contains the segment that generated the current
1332 * ACK and the following ones are the ones most recently reported in SACK
1335 * @param tc TCP connection for which the SACK list is updated
1336 * @param start Start sequence number of the newest SACK block
1337 * @param end End sequence of the newest SACK block
1340 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1342 sack_block_t *new_list = 0, *block = 0;
1345 /* If the first segment is ooo add it to the list. Last write might've moved
1346 * rcv_nxt over the first segment. */
1347 if (seq_lt (tc->rcv_nxt, start))
1349 vec_add2 (new_list, block, 1);
1350 block->start = start;
1354 /* Find the blocks still worth keeping. */
1355 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1357 /* Discard if rcv_nxt advanced beyond current block */
1358 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1361 /* Merge or drop if segment overlapped by the new segment */
1362 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1363 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1365 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1366 new_list[0].start = tc->snd_sacks[i].start;
1367 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1368 new_list[0].end = tc->snd_sacks[i].end;
1372 /* Save to new SACK list if we have space. */
1373 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1375 vec_add1 (new_list, tc->snd_sacks[i]);
1379 clib_warning ("sack discarded");
1383 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1385 /* Replace old vector with new one */
1386 vec_free (tc->snd_sacks);
1387 tc->snd_sacks = new_list;
1389 /* Segments should not 'touch' */
1390 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1393 /** Enqueue data for delivery to application */
1395 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1398 int written, error = TCP_ERROR_ENQUEUED;
1400 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1402 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1403 1 /* queue event */ , 1);
1405 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1407 /* Update rcv_nxt */
1408 if (PREDICT_TRUE (written == data_len))
1410 tc->rcv_nxt += written;
1412 /* If more data written than expected, account for out-of-order bytes. */
1413 else if (written > data_len)
1415 tc->rcv_nxt += written;
1417 /* Send ACK confirming the update */
1418 tc->flags |= TCP_CONN_SNDACK;
1420 else if (written > 0)
1422 /* We've written something but FIFO is probably full now */
1423 tc->rcv_nxt += written;
1425 /* Depending on how fast the app is, all remaining buffers in burst will
1426 * not be enqueued. Inform peer */
1427 tc->flags |= TCP_CONN_SNDACK;
1429 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1433 tc->flags |= TCP_CONN_SNDACK;
1434 return TCP_ERROR_FIFO_FULL;
1437 /* Update SACK list if need be */
1438 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1440 /* Remove SACK blocks that have been delivered */
1441 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1447 /** Enqueue out-of-order data */
1449 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1452 stream_session_t *s0;
1455 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1458 /* Enqueue out-of-order data with relative offset */
1459 rv = session_enqueue_stream_connection (&tc->connection, b,
1460 vnet_buffer (b)->tcp.seq_number -
1461 tc->rcv_nxt, 0 /* queue event */ ,
1464 /* Nothing written */
1467 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1468 return TCP_ERROR_FIFO_FULL;
1471 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1473 /* Update SACK list if in use */
1474 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1476 ooo_segment_t *newest;
1479 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1481 /* Get the newest segment from the fifo */
1482 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1485 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1486 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1487 start = tc->rcv_nxt + offset;
1488 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1489 tcp_update_sack_list (tc, start, end);
1490 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1494 return TCP_ERROR_ENQUEUED_OOO;
1498 * Check if ACK could be delayed. If ack can be delayed, it should return
1499 * true for a full frame. If we're always acking return 0.
1502 tcp_can_delack (tcp_connection_t * tc)
1504 /* Send ack if ... */
1506 /* just sent a rcv wnd 0 */
1507 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1508 /* constrained to send ack */
1509 || (tc->flags & TCP_CONN_SNDACK) != 0
1510 /* we're almost out of tx wnd */
1511 || tcp_available_snd_space (tc) < 4 * tc->snd_mss)
1518 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1520 u32 discard, first = b->current_length;
1521 vlib_main_t *vm = vlib_get_main ();
1523 /* Handle multi-buffer segments */
1524 if (n_bytes_to_drop > b->current_length)
1526 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1530 discard = clib_min (n_bytes_to_drop, b->current_length);
1531 vlib_buffer_advance (b, discard);
1532 b = vlib_get_buffer (vm, b->next_buffer);
1533 n_bytes_to_drop -= discard;
1535 while (n_bytes_to_drop);
1536 if (n_bytes_to_drop > first)
1537 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1540 vlib_buffer_advance (b, n_bytes_to_drop);
1541 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1546 * Receive buffer for connection and handle acks
1548 * It handles both in order or out-of-order data.
1551 tcp_segment_rcv (tcp_connection_t * tc, vlib_buffer_t * b, u32 * next0)
1553 u32 error, n_bytes_to_drop, n_data_bytes;
1555 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1556 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1557 ASSERT (n_data_bytes);
1559 /* Handle out-of-order data */
1560 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1562 /* Old sequence numbers allowed through because they overlapped
1564 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1566 /* Completely in the past (possible retransmit). Ack
1567 * retransmissions since we may not have any data to send */
1568 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1570 tcp_make_ack (tc, b);
1571 error = TCP_ERROR_SEGMENT_OLD;
1572 *next0 = tcp_next_output (tc->c_is_ip4);
1576 /* Chop off the bytes in the past and see if what is left
1577 * can be enqueued in order */
1578 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1579 n_data_bytes -= n_bytes_to_drop;
1580 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1581 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1583 error = TCP_ERROR_SEGMENT_OLD;
1584 *next0 = tcp_next_drop (tc->c_is_ip4);
1590 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1591 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1592 *next0 = tcp_next_output (tc->c_is_ip4);
1593 tcp_make_ack (tc, b);
1594 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1595 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1601 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1602 * segments can be enqueued after fifo tail offset changes. */
1603 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1604 if (tcp_can_delack (tc))
1606 *next0 = tcp_next_drop (tc->c_is_ip4);
1607 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1608 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1612 *next0 = tcp_next_output (tc->c_is_ip4);
1613 tcp_make_ack (tc, b);
1621 tcp_header_t tcp_header;
1622 tcp_connection_t tcp_connection;
1626 format_tcp_rx_trace (u8 * s, va_list * args)
1628 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1629 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1630 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1631 u32 indent = format_get_indent (s);
1633 s = format (s, "%U\n%U%U",
1634 format_tcp_header, &t->tcp_header, 128,
1635 format_white_space, indent,
1636 format_tcp_connection, &t->tcp_connection, 1);
1642 format_tcp_rx_trace_short (u8 * s, va_list * args)
1644 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1645 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1646 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1648 s = format (s, "%d -> %d (%U)",
1649 clib_net_to_host_u16 (t->tcp_header.src_port),
1650 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1651 t->tcp_connection.state);
1657 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1658 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1662 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1666 th0 = tcp_buffer_hdr (b0);
1668 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1672 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1673 u8 is_ip4, u32 evt, u32 val)
1676 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1678 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1681 #define tcp_maybe_inc_counter(node_id, err, count) \
1683 if (next0 != tcp_next_drop (is_ip4)) \
1684 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1685 tcp6_##node_id##_node.index, is_ip4, err, \
1688 #define tcp_inc_counter(node_id, err, count) \
1689 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1690 tcp6_##node_id##_node.index, is_ip4, \
1692 #define tcp_maybe_inc_err_counter(cnts, err) \
1694 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
1696 #define tcp_inc_err_counter(cnts, err, val) \
1700 #define tcp_store_err_counters(node_id, cnts) \
1703 for (i = 0; i < TCP_N_ERROR; i++) \
1705 tcp_inc_counter(node_id, i, cnts[i]); \
1710 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1711 vlib_frame_t * from_frame, int is_ip4)
1713 u32 my_thread_index = vm->thread_index, errors = 0;
1714 u32 n_left_from, next_index, *from, *to_next;
1715 u16 err_counters[TCP_N_ERROR] = { 0 };
1718 from = vlib_frame_vector_args (from_frame);
1719 n_left_from = from_frame->n_vectors;
1720 next_index = node->cached_next_index;
1722 while (n_left_from > 0)
1726 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1727 while (n_left_from > 0 && n_left_to_next > 0)
1731 tcp_header_t *th0 = 0;
1732 tcp_connection_t *tc0;
1733 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ACK_OK;
1735 if (n_left_from > 1)
1738 pb = vlib_get_buffer (vm, from[1]);
1739 vlib_prefetch_buffer_header (pb, LOAD);
1740 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
1748 n_left_to_next -= 1;
1750 b0 = vlib_get_buffer (vm, bi0);
1751 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1754 if (PREDICT_FALSE (tc0 == 0))
1756 error0 = TCP_ERROR_INVALID_CONNECTION;
1760 th0 = tcp_buffer_hdr (b0);
1761 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1762 * dangling reference. */
1763 is_fin = tcp_is_fin (th0);
1765 /* SYNs, FINs and data consume sequence numbers */
1766 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1767 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1769 /* TODO header prediction fast path */
1771 /* 1-4: check SEQ, RST, SYN */
1772 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0,
1775 tcp_maybe_inc_err_counter (err_counters, error0);
1776 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1777 vnet_buffer (b0)->tcp.seq_number,
1778 vnet_buffer (b0)->tcp.seq_end);
1782 /* 5: check the ACK field */
1783 if (PREDICT_FALSE (tcp_rcv_ack (tc0, b0, th0, &next0, &error0)))
1785 tcp_maybe_inc_err_counter (err_counters, error0);
1789 /* 6: check the URG bit TODO */
1791 /* 7: process the segment text */
1792 if (vnet_buffer (b0)->tcp.data_len)
1794 error0 = tcp_segment_rcv (tc0, b0, &next0);
1795 tcp_maybe_inc_err_counter (err_counters, error0);
1798 /* 8: check the FIN bit */
1799 if (PREDICT_FALSE (is_fin))
1801 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1802 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1803 /* Account for the FIN if nothing else was received */
1804 if (vnet_buffer (b0)->tcp.data_len == 0)
1806 tcp_make_ack (tc0, b0);
1807 next0 = tcp_next_output (tc0->c_is_ip4);
1808 tc0->state = TCP_STATE_CLOSE_WAIT;
1809 stream_session_disconnect_notify (&tc0->connection);
1810 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1811 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1812 tcp_inc_err_counter (err_counters, TCP_ERROR_FIN_RCVD, 1);
1816 b0->error = node->errors[error0];
1817 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1819 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0,
1821 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1824 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1825 n_left_to_next, bi0, next0);
1828 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1831 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
1833 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
1834 tcp_store_err_counters (established, err_counters);
1835 tcp_flush_frame_to_output (vm, my_thread_index, is_ip4);
1836 return from_frame->n_vectors;
1840 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1841 vlib_frame_t * from_frame)
1843 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1847 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1848 vlib_frame_t * from_frame)
1850 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1854 VLIB_REGISTER_NODE (tcp4_established_node) =
1856 .function = tcp4_established,
1857 .name = "tcp4-established",
1858 /* Takes a vector of packets. */
1859 .vector_size = sizeof (u32),
1860 .n_errors = TCP_N_ERROR,
1861 .error_strings = tcp_error_strings,
1862 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1865 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1866 foreach_tcp_state_next
1869 .format_trace = format_tcp_rx_trace_short,
1873 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1876 VLIB_REGISTER_NODE (tcp6_established_node) =
1878 .function = tcp6_established,
1879 .name = "tcp6-established",
1880 /* Takes a vector of packets. */
1881 .vector_size = sizeof (u32),
1882 .n_errors = TCP_N_ERROR,
1883 .error_strings = tcp_error_strings,
1884 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1887 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1888 foreach_tcp_state_next
1891 .format_trace = format_tcp_rx_trace_short,
1896 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1898 vlib_node_registration_t tcp4_syn_sent_node;
1899 vlib_node_registration_t tcp6_syn_sent_node;
1902 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
1904 transport_connection_t *tmp = 0;
1911 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
1914 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
1915 && (tc->state == TCP_STATE_LISTEN
1916 || tc->c_rmt_port == hdr->src_port));
1920 handle = session_lookup_half_open_handle (&tc->connection);
1921 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
1922 tc->c_proto, tc->c_is_ip4);
1926 if (tmp->lcl_port == hdr->dst_port
1927 && tmp->rmt_port == hdr->src_port)
1929 TCP_DBG ("half-open is valid!");
1937 * Lookup transport connection
1939 static tcp_connection_t *
1940 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
1944 transport_connection_t *tconn;
1945 tcp_connection_t *tc;
1950 ip4 = vlib_buffer_get_current (b);
1951 tcp = ip4_next_header (ip4);
1952 tconn = session_lookup_connection_wt4 (fib_index,
1957 TRANSPORT_PROTO_TCP,
1958 thread_index, &is_filtered);
1959 tc = tcp_get_connection_from_transport (tconn);
1960 ASSERT (tcp_lookup_is_valid (tc, tcp));
1965 ip6 = vlib_buffer_get_current (b);
1966 tcp = ip6_next_header (ip6);
1967 tconn = session_lookup_connection_wt6 (fib_index,
1972 TRANSPORT_PROTO_TCP,
1973 thread_index, &is_filtered);
1974 tc = tcp_get_connection_from_transport (tconn);
1975 ASSERT (tcp_lookup_is_valid (tc, tcp));
1981 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1982 vlib_frame_t * from_frame, int is_ip4)
1984 tcp_main_t *tm = vnet_get_tcp_main ();
1985 u32 n_left_from, next_index, *from, *to_next;
1986 u32 my_thread_index = vm->thread_index, errors = 0;
1988 from = vlib_frame_vector_args (from_frame);
1989 n_left_from = from_frame->n_vectors;
1991 next_index = node->cached_next_index;
1993 while (n_left_from > 0)
1997 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1999 while (n_left_from > 0 && n_left_to_next > 0)
2001 u32 bi0, ack0, seq0;
2004 tcp_header_t *tcp0 = 0;
2005 tcp_connection_t *tc0;
2006 tcp_connection_t *new_tc0;
2007 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
2014 n_left_to_next -= 1;
2016 b0 = vlib_get_buffer (vm, bi0);
2018 tcp_half_open_connection_get (vnet_buffer (b0)->
2019 tcp.connection_index);
2020 if (PREDICT_FALSE (tc0 == 0))
2022 error0 = TCP_ERROR_INVALID_CONNECTION;
2026 /* Half-open completed recently but the connection was't removed
2027 * yet by the owning thread */
2028 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2030 /* Make sure the connection actually exists */
2031 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2032 my_thread_index, is_ip4));
2036 ack0 = vnet_buffer (b0)->tcp.ack_number;
2037 seq0 = vnet_buffer (b0)->tcp.seq_number;
2038 tcp0 = tcp_buffer_hdr (b0);
2040 /* Crude check to see if the connection handle does not match
2041 * the packet. Probably connection just switched to established */
2042 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2043 || tcp0->src_port != tc0->c_rmt_port))
2047 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
2050 /* SYNs, FINs and data consume sequence numbers */
2051 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
2052 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
2055 * 1. check the ACK bit
2059 * If the ACK bit is set
2060 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2061 * the RST bit is set, if so drop the segment and return)
2062 * <SEQ=SEG.ACK><CTL=RST>
2063 * and discard the segment. Return.
2064 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2068 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2070 clib_warning ("ack not in rcv wnd");
2071 if (!tcp_rst (tcp0))
2072 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2076 /* Make sure ACK is valid */
2077 if (seq_gt (tc0->snd_una, ack0))
2079 clib_warning ("ack invalid");
2085 * 2. check the RST bit
2090 /* If ACK is acceptable, signal client that peer is not
2091 * willing to accept connection and drop connection*/
2093 tcp_connection_reset (tc0);
2098 * 3. check the security and precedence (skipped)
2102 * 4. check the SYN bit
2105 /* No SYN flag. Drop. */
2106 if (!tcp_syn (tcp0))
2108 clib_warning ("not synack");
2113 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2115 clib_warning ("options parse fail");
2119 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2120 * current thread pool. */
2121 pool_get (tm->connections[my_thread_index], new_tc0);
2122 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2123 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2124 new_tc0->c_thread_index = my_thread_index;
2125 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2126 new_tc0->irs = seq0;
2127 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2128 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2129 TCP_TIMER_HANDLE_INVALID;
2130 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2132 /* If this is not the owning thread, wait for syn retransmit to
2133 * expire and cleanup then */
2134 if (tcp_half_open_connection_cleanup (tc0))
2135 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2137 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2139 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2140 new_tc0->tsval_recent_age = tcp_time_now ();
2143 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2144 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2146 /* RFC1323: SYN and SYN-ACK wnd not scaled */
2147 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
2148 new_tc0->snd_wl1 = seq0;
2149 new_tc0->snd_wl2 = ack0;
2151 tcp_connection_init_vars (new_tc0);
2153 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2154 if (PREDICT_TRUE (tcp_ack (tcp0)))
2156 /* Our SYN is ACKed: we have iss < ack = snd_una */
2158 /* TODO Dequeue acknowledged segments if we support Fast Open */
2159 new_tc0->snd_una = ack0;
2160 new_tc0->state = TCP_STATE_ESTABLISHED;
2162 /* Make sure las is initialized for the wnd computation */
2163 new_tc0->rcv_las = new_tc0->rcv_nxt;
2165 /* Notify app that we have connection. If session layer can't
2166 * allocate session send reset */
2167 if (session_stream_connect_notify (&new_tc0->connection, 0))
2169 clib_warning ("connect notify fail");
2170 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2171 tcp_connection_cleanup (new_tc0);
2175 /* Make sure after data segment processing ACK is sent */
2176 new_tc0->flags |= TCP_CONN_SNDACK;
2178 /* Update rtt with the syn-ack sample */
2179 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2180 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2182 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2185 new_tc0->state = TCP_STATE_SYN_RCVD;
2187 /* Notify app that we have connection */
2188 if (session_stream_connect_notify (&new_tc0->connection, 0))
2190 tcp_connection_cleanup (new_tc0);
2191 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2192 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2197 tcp_init_snd_vars (tc0);
2198 tcp_make_synack (new_tc0, b0);
2199 next0 = tcp_next_output (is_ip4);
2204 /* Read data, if any */
2205 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2207 clib_warning ("rcvd data in syn-sent");
2208 error0 = tcp_segment_rcv (new_tc0, b0, &next0);
2209 if (error0 == TCP_ERROR_ACK_OK)
2210 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2211 tcp_maybe_inc_counter (syn_sent, error0, 1);
2215 tcp_make_ack (new_tc0, b0);
2216 next0 = tcp_next_output (new_tc0->c_is_ip4);
2221 b0->error = error0 ? node->errors[error0] : 0;
2223 ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2225 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2226 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2227 clib_memcpy (&t0->tcp_connection, tc0,
2228 sizeof (t0->tcp_connection));
2231 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2232 n_left_to_next, bi0, next0);
2235 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2238 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2240 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2241 return from_frame->n_vectors;
2245 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2246 vlib_frame_t * from_frame)
2248 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2252 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2253 vlib_frame_t * from_frame)
2255 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2259 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2261 .function = tcp4_syn_sent,
2262 .name = "tcp4-syn-sent",
2263 /* Takes a vector of packets. */
2264 .vector_size = sizeof (u32),
2265 .n_errors = TCP_N_ERROR,
2266 .error_strings = tcp_error_strings,
2267 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2270 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2271 foreach_tcp_state_next
2274 .format_trace = format_tcp_rx_trace_short,
2278 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2281 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2283 .function = tcp6_syn_sent_rcv,
2284 .name = "tcp6-syn-sent",
2285 /* Takes a vector of packets. */
2286 .vector_size = sizeof (u32),
2287 .n_errors = TCP_N_ERROR,
2288 .error_strings = tcp_error_strings,
2289 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2292 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2293 foreach_tcp_state_next
2296 .format_trace = format_tcp_rx_trace_short,
2300 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2302 vlib_node_registration_t tcp4_rcv_process_node;
2303 vlib_node_registration_t tcp6_rcv_process_node;
2306 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2307 * as per RFC793 p. 64
2310 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2311 vlib_frame_t * from_frame, int is_ip4)
2313 u32 n_left_from, next_index, *from, *to_next, n_fins = 0;
2314 u32 my_thread_index = vm->thread_index, errors = 0;
2316 from = vlib_frame_vector_args (from_frame);
2317 n_left_from = from_frame->n_vectors;
2318 next_index = node->cached_next_index;
2320 while (n_left_from > 0)
2324 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2326 while (n_left_from > 0 && n_left_to_next > 0)
2330 tcp_header_t *tcp0 = 0;
2331 tcp_connection_t *tc0;
2332 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_NONE;
2340 n_left_to_next -= 1;
2342 b0 = vlib_get_buffer (vm, bi0);
2343 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2345 if (PREDICT_FALSE (tc0 == 0))
2347 error0 = TCP_ERROR_INVALID_CONNECTION;
2351 tcp0 = tcp_buffer_hdr (b0);
2352 is_fin0 = tcp_is_fin (tcp0);
2354 /* SYNs, FINs and data consume sequence numbers */
2355 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2356 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2360 tcp_connection_t *tmp;
2361 tmp = tcp_lookup_connection (tc0->c_fib_index, b0,
2362 my_thread_index, is_ip4);
2363 if (tmp->state != tc0->state)
2365 clib_warning ("state changed");
2371 * Special treatment for CLOSED
2373 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2375 error0 = TCP_ERROR_CONNECTION_CLOSED;
2380 * For all other states (except LISTEN)
2383 /* 1-4: check SEQ, RST, SYN */
2384 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2387 tcp_maybe_inc_counter (rcv_process, error0, 1);
2391 /* 5: check the ACK field */
2394 case TCP_STATE_SYN_RCVD:
2396 * If the segment acknowledgment is not acceptable, form a
2398 * <SEQ=SEG.ACK><CTL=RST>
2401 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2403 TCP_DBG ("connection not accepted");
2404 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2405 error0 = TCP_ERROR_ACK_INVALID;
2409 /* Update rtt and rto */
2410 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2412 /* Switch state to ESTABLISHED */
2413 tc0->state = TCP_STATE_ESTABLISHED;
2414 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2416 /* Initialize session variables */
2417 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2418 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2419 << tc0->rcv_opts.wscale;
2420 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2421 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2423 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2424 tcp_retransmit_timer_reset (tc0);
2425 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2426 stream_session_accept_notify (&tc0->connection);
2427 error0 = TCP_ERROR_ACK_OK;
2429 case TCP_STATE_ESTABLISHED:
2430 /* We can get packets in established state here because they
2431 * were enqueued before state change */
2432 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2434 tcp_maybe_inc_counter (rcv_process, error0, 1);
2439 case TCP_STATE_FIN_WAIT_1:
2440 /* In addition to the processing for the ESTABLISHED state, if
2441 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2442 * continue processing in that state. */
2443 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2445 tcp_maybe_inc_counter (rcv_process, error0, 1);
2449 /* Still have to send the FIN */
2450 if (tc0->flags & TCP_CONN_FINPNDG)
2452 /* TX fifo finally drained */
2453 if (!stream_session_tx_fifo_max_dequeue (&tc0->connection))
2456 /* If FIN is ACKed */
2457 else if (tc0->snd_una == tc0->snd_una_max)
2459 tc0->state = TCP_STATE_FIN_WAIT_2;
2460 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2462 /* Stop all retransmit timers because we have nothing more
2463 * to send. Enable waitclose though because we're willing to
2464 * wait for peer's FIN but not indefinitely. */
2465 tcp_connection_timers_reset (tc0);
2466 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2469 case TCP_STATE_FIN_WAIT_2:
2470 /* In addition to the processing for the ESTABLISHED state, if
2471 * the retransmission queue is empty, the user's CLOSE can be
2472 * acknowledged ("ok") but do not delete the TCB. */
2473 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2475 tcp_maybe_inc_counter (rcv_process, error0, 1);
2479 case TCP_STATE_CLOSE_WAIT:
2480 /* Do the same processing as for the ESTABLISHED state. */
2481 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2483 tcp_maybe_inc_counter (rcv_process, error0, 1);
2487 case TCP_STATE_CLOSING:
2488 /* In addition to the processing for the ESTABLISHED state, if
2489 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2490 * otherwise ignore the segment. */
2491 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2493 tcp_maybe_inc_counter (rcv_process, error0, 1);
2497 tc0->state = TCP_STATE_TIME_WAIT;
2498 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2499 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2503 case TCP_STATE_LAST_ACK:
2504 /* The only thing that [should] arrive in this state is an
2505 * acknowledgment of our FIN. If our FIN is now acknowledged,
2506 * delete the TCB, enter the CLOSED state, and return. */
2508 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2510 error0 = TCP_ERROR_ACK_INVALID;
2513 error0 = TCP_ERROR_ACK_OK;
2514 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2515 /* Apparently our ACK for the peer's FIN was lost */
2516 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2522 tc0->state = TCP_STATE_CLOSED;
2523 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2524 tcp_connection_timers_reset (tc0);
2526 /* Don't delete the connection/session yet. Instead, wait a
2527 * reasonable amount of time until the pipes are cleared. In
2528 * particular, this makes sure that we won't have dead sessions
2529 * when processing events on the tx path */
2530 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2535 case TCP_STATE_TIME_WAIT:
2536 /* The only thing that can arrive in this state is a
2537 * retransmission of the remote FIN. Acknowledge it, and restart
2538 * the 2 MSL timeout. */
2540 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2542 tcp_maybe_inc_counter (rcv_process, error0, 1);
2546 tcp_make_ack (tc0, b0);
2547 next0 = tcp_next_output (is_ip4);
2548 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2556 /* 6: check the URG bit TODO */
2558 /* 7: process the segment text */
2561 case TCP_STATE_ESTABLISHED:
2562 case TCP_STATE_FIN_WAIT_1:
2563 case TCP_STATE_FIN_WAIT_2:
2564 if (vnet_buffer (b0)->tcp.data_len)
2566 error0 = tcp_segment_rcv (tc0, b0, &next0);
2567 tcp_maybe_inc_counter (rcv_process, error0, 1);
2572 case TCP_STATE_CLOSE_WAIT:
2573 case TCP_STATE_CLOSING:
2574 case TCP_STATE_LAST_ACK:
2575 case TCP_STATE_TIME_WAIT:
2576 /* This should not occur, since a FIN has been received from the
2577 * remote side. Ignore the segment text. */
2581 /* 8: check the FIN bit */
2587 case TCP_STATE_ESTABLISHED:
2588 case TCP_STATE_SYN_RCVD:
2589 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2590 tcp_connection_timers_reset (tc0);
2591 tcp_make_fin (tc0, b0);
2593 next0 = tcp_next_output (tc0->c_is_ip4);
2594 stream_session_disconnect_notify (&tc0->connection);
2595 tc0->state = TCP_STATE_CLOSE_WAIT;
2596 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2598 case TCP_STATE_CLOSE_WAIT:
2599 case TCP_STATE_CLOSING:
2600 case TCP_STATE_LAST_ACK:
2603 case TCP_STATE_FIN_WAIT_1:
2604 tc0->state = TCP_STATE_CLOSING;
2605 tcp_make_ack (tc0, b0);
2606 next0 = tcp_next_output (is_ip4);
2607 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2608 /* Wait for ACK but not forever */
2609 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2611 case TCP_STATE_FIN_WAIT_2:
2612 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2613 tc0->state = TCP_STATE_TIME_WAIT;
2614 tcp_connection_timers_reset (tc0);
2615 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2616 tcp_make_ack (tc0, b0);
2617 next0 = tcp_next_output (is_ip4);
2618 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2620 case TCP_STATE_TIME_WAIT:
2621 /* Remain in the TIME-WAIT state. Restart the time-wait
2624 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2627 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2631 b0->error = error0 ? node->errors[error0] : 0;
2633 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2635 tcp_rx_trace_t *t0 =
2636 vlib_add_trace (vm, node, b0, sizeof (*t0));
2637 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2640 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2641 n_left_to_next, bi0, next0);
2644 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2647 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2649 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2650 tcp_inc_counter (rcv_process, TCP_ERROR_FIN_RCVD, n_fins);
2651 return from_frame->n_vectors;
2655 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2656 vlib_frame_t * from_frame)
2658 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2662 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2663 vlib_frame_t * from_frame)
2665 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2669 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2671 .function = tcp4_rcv_process,
2672 .name = "tcp4-rcv-process",
2673 /* Takes a vector of packets. */
2674 .vector_size = sizeof (u32),
2675 .n_errors = TCP_N_ERROR,
2676 .error_strings = tcp_error_strings,
2677 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2680 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2681 foreach_tcp_state_next
2684 .format_trace = format_tcp_rx_trace_short,
2688 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2691 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2693 .function = tcp6_rcv_process,
2694 .name = "tcp6-rcv-process",
2695 /* Takes a vector of packets. */
2696 .vector_size = sizeof (u32),
2697 .n_errors = TCP_N_ERROR,
2698 .error_strings = tcp_error_strings,
2699 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2702 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2703 foreach_tcp_state_next
2706 .format_trace = format_tcp_rx_trace_short,
2710 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2712 vlib_node_registration_t tcp4_listen_node;
2713 vlib_node_registration_t tcp6_listen_node;
2716 * LISTEN state processing as per RFC 793 p. 65
2719 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2720 vlib_frame_t * from_frame, int is_ip4)
2722 u32 n_left_from, next_index, *from, *to_next, n_syns = 0;
2723 u32 my_thread_index = vm->thread_index;
2725 from = vlib_frame_vector_args (from_frame);
2726 n_left_from = from_frame->n_vectors;
2728 next_index = node->cached_next_index;
2730 while (n_left_from > 0)
2734 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2736 while (n_left_from > 0 && n_left_to_next > 0)
2741 tcp_header_t *th0 = 0;
2742 tcp_connection_t *lc0;
2745 tcp_connection_t *child0;
2746 u32 error0 = TCP_ERROR_NONE, next0 = tcp_next_drop (is_ip4);
2753 n_left_to_next -= 1;
2755 b0 = vlib_get_buffer (vm, bi0);
2756 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2760 ip40 = vlib_buffer_get_current (b0);
2761 th0 = ip4_next_header (ip40);
2765 ip60 = vlib_buffer_get_current (b0);
2766 th0 = ip6_next_header (ip60);
2769 /* Create child session. For syn-flood protection use filter */
2771 /* 1. first check for an RST: handled in dispatch */
2772 /* if (tcp_rst (th0))
2775 /* 2. second check for an ACK: handled in dispatch */
2776 /* if (tcp_ack (th0))
2778 tcp_send_reset (b0, is_ip4);
2782 /* 3. check for a SYN (did that already) */
2784 /* Make sure connection wasn't just created */
2785 child0 = tcp_lookup_connection (lc0->c_fib_index, b0,
2786 my_thread_index, is_ip4);
2787 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
2789 error0 = TCP_ERROR_CREATE_EXISTS;
2793 /* Create child session and send SYN-ACK */
2794 child0 = tcp_connection_new (my_thread_index);
2795 child0->c_lcl_port = th0->dst_port;
2796 child0->c_rmt_port = th0->src_port;
2797 child0->c_is_ip4 = is_ip4;
2798 child0->state = TCP_STATE_SYN_RCVD;
2799 child0->c_fib_index = lc0->c_fib_index;
2803 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2804 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2808 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2809 sizeof (ip6_address_t));
2810 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2811 sizeof (ip6_address_t));
2814 if (tcp_options_parse (th0, &child0->rcv_opts))
2816 clib_warning ("options parse fail");
2820 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2821 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2822 child0->rcv_las = child0->rcv_nxt;
2823 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2825 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2826 * segments are used to initialize PAWS. */
2827 if (tcp_opts_tstamp (&child0->rcv_opts))
2829 child0->tsval_recent = child0->rcv_opts.tsval;
2830 child0->tsval_recent_age = tcp_time_now ();
2833 if (tcp_opts_wscale (&child0->rcv_opts))
2834 child0->snd_wscale = child0->rcv_opts.wscale;
2836 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2837 << child0->snd_wscale;
2838 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2839 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2841 tcp_connection_init_vars (child0);
2842 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
2844 if (stream_session_accept (&child0->connection, lc0->c_s_index,
2847 clib_warning ("session accept fail");
2848 tcp_connection_cleanup (child0);
2849 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2853 /* Reuse buffer to make syn-ack and send */
2854 tcp_make_synack (child0, b0);
2855 next0 = tcp_next_output (is_ip4);
2856 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
2859 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2861 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2862 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2863 clib_memcpy (&t0->tcp_connection, lc0,
2864 sizeof (t0->tcp_connection));
2867 n_syns += (error0 == TCP_ERROR_NONE);
2868 b0->error = node->errors[error0];
2870 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2871 n_left_to_next, bi0, next0);
2874 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2877 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
2878 return from_frame->n_vectors;
2882 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2883 vlib_frame_t * from_frame)
2885 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2889 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2890 vlib_frame_t * from_frame)
2892 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2896 VLIB_REGISTER_NODE (tcp4_listen_node) =
2898 .function = tcp4_listen,
2899 .name = "tcp4-listen",
2900 /* Takes a vector of packets. */
2901 .vector_size = sizeof (u32),
2902 .n_errors = TCP_N_ERROR,
2903 .error_strings = tcp_error_strings,
2904 .n_next_nodes = TCP_LISTEN_N_NEXT,
2907 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2908 foreach_tcp_state_next
2911 .format_trace = format_tcp_rx_trace_short,
2915 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2918 VLIB_REGISTER_NODE (tcp6_listen_node) =
2920 .function = tcp6_listen,
2921 .name = "tcp6-listen",
2922 /* Takes a vector of packets. */
2923 .vector_size = sizeof (u32),
2924 .n_errors = TCP_N_ERROR,
2925 .error_strings = tcp_error_strings,
2926 .n_next_nodes = TCP_LISTEN_N_NEXT,
2929 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2930 foreach_tcp_state_next
2933 .format_trace = format_tcp_rx_trace_short,
2937 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2939 vlib_node_registration_t tcp4_input_node;
2940 vlib_node_registration_t tcp6_input_node;
2942 typedef enum _tcp_input_next
2944 TCP_INPUT_NEXT_DROP,
2945 TCP_INPUT_NEXT_LISTEN,
2946 TCP_INPUT_NEXT_RCV_PROCESS,
2947 TCP_INPUT_NEXT_SYN_SENT,
2948 TCP_INPUT_NEXT_ESTABLISHED,
2949 TCP_INPUT_NEXT_RESET,
2950 TCP_INPUT_NEXT_PUNT,
2954 #define foreach_tcp4_input_next \
2955 _ (DROP, "ip4-drop") \
2956 _ (LISTEN, "tcp4-listen") \
2957 _ (RCV_PROCESS, "tcp4-rcv-process") \
2958 _ (SYN_SENT, "tcp4-syn-sent") \
2959 _ (ESTABLISHED, "tcp4-established") \
2960 _ (RESET, "tcp4-reset") \
2961 _ (PUNT, "ip4-punt")
2963 #define foreach_tcp6_input_next \
2964 _ (DROP, "ip6-drop") \
2965 _ (LISTEN, "tcp6-listen") \
2966 _ (RCV_PROCESS, "tcp6-rcv-process") \
2967 _ (SYN_SENT, "tcp6-syn-sent") \
2968 _ (ESTABLISHED, "tcp6-established") \
2969 _ (RESET, "tcp6-reset") \
2970 _ (PUNT, "ip6-punt")
2972 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2975 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2976 vlib_frame_t * from_frame, int is_ip4)
2978 u32 n_left_from, next_index, *from, *to_next;
2979 u32 my_thread_index = vm->thread_index;
2980 tcp_main_t *tm = vnet_get_tcp_main ();
2982 from = vlib_frame_vector_args (from_frame);
2983 n_left_from = from_frame->n_vectors;
2984 next_index = node->cached_next_index;
2985 tcp_set_time_now (my_thread_index);
2987 while (n_left_from > 0)
2991 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2993 while (n_left_from > 0 && n_left_to_next > 0)
2995 int n_advance_bytes0, n_data_bytes0;
2996 u32 bi0, fib_index0;
2998 tcp_header_t *tcp0 = 0;
2999 tcp_connection_t *tc0;
3000 transport_connection_t *tconn;
3003 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
3004 u8 flags0, is_filtered = 0;
3011 n_left_to_next -= 1;
3013 b0 = vlib_get_buffer (vm, bi0);
3014 vnet_buffer (b0)->tcp.flags = 0;
3015 fib_index0 = vnet_buffer (b0)->ip.fib_index;
3017 /* Checksum computed by ipx_local no need to compute again */
3021 ip40 = vlib_buffer_get_current (b0);
3022 tcp0 = ip4_next_header (ip40);
3023 n_advance_bytes0 = (ip4_header_bytes (ip40)
3024 + tcp_header_bytes (tcp0));
3025 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
3027 tconn = session_lookup_connection_wt4 (fib_index0,
3032 TRANSPORT_PROTO_TCP,
3038 ip60 = vlib_buffer_get_current (b0);
3039 tcp0 = ip6_next_header (ip60);
3040 n_advance_bytes0 = tcp_header_bytes (tcp0);
3041 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
3043 n_advance_bytes0 += sizeof (ip60[0]);
3044 tconn = session_lookup_connection_wt6 (fib_index0,
3049 TRANSPORT_PROTO_TCP,
3055 if (PREDICT_FALSE (n_advance_bytes0 < 0))
3057 error0 = TCP_ERROR_LENGTH;
3061 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
3062 - (u8 *) vlib_buffer_get_current (b0);
3064 /* Session exists */
3065 if (PREDICT_TRUE (0 != tconn))
3067 tc0 = tcp_get_connection_from_transport (tconn);
3068 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
3070 /* Save connection index */
3071 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
3072 vnet_buffer (b0)->tcp.seq_number =
3073 clib_net_to_host_u32 (tcp0->seq_number);
3074 vnet_buffer (b0)->tcp.ack_number =
3075 clib_net_to_host_u32 (tcp0->ack_number);
3077 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
3078 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
3080 flags0 = tcp0->flags & filter_flags;
3081 next0 = tm->dispatch_table[tc0->state][flags0].next;
3082 error0 = tm->dispatch_table[tc0->state][flags0].error;
3084 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH
3085 || next0 == TCP_INPUT_NEXT_RESET))
3087 /* Overload tcp flags to store state */
3088 tcp_state_t state0 = tc0->state;
3089 vnet_buffer (b0)->tcp.flags = tc0->state;
3091 if (error0 == TCP_ERROR_DISPATCH)
3092 clib_warning ("disp error state %U flags %U",
3093 format_tcp_state, state0, format_tcp_flags,
3101 next0 = TCP_INPUT_NEXT_DROP;
3102 error0 = TCP_ERROR_FILTERED;
3104 else if ((is_ip4 && tm->punt_unknown4) ||
3105 (!is_ip4 && tm->punt_unknown6))
3107 next0 = TCP_INPUT_NEXT_PUNT;
3108 error0 = TCP_ERROR_PUNT;
3113 next0 = TCP_INPUT_NEXT_RESET;
3114 error0 = TCP_ERROR_NO_LISTENER;
3120 b0->error = error0 ? node->errors[error0] : 0;
3122 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3125 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3126 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3128 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
3129 n_left_to_next, bi0, next0);
3132 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3135 return from_frame->n_vectors;
3139 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3140 vlib_frame_t * from_frame)
3142 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3146 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3147 vlib_frame_t * from_frame)
3149 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3153 VLIB_REGISTER_NODE (tcp4_input_node) =
3155 .function = tcp4_input,
3156 .name = "tcp4-input",
3157 /* Takes a vector of packets. */
3158 .vector_size = sizeof (u32),
3159 .n_errors = TCP_N_ERROR,
3160 .error_strings = tcp_error_strings,
3161 .n_next_nodes = TCP_INPUT_N_NEXT,
3164 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3165 foreach_tcp4_input_next
3168 .format_buffer = format_tcp_header,
3169 .format_trace = format_tcp_rx_trace,
3173 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3176 VLIB_REGISTER_NODE (tcp6_input_node) =
3178 .function = tcp6_input,
3179 .name = "tcp6-input",
3180 /* Takes a vector of packets. */
3181 .vector_size = sizeof (u32),
3182 .n_errors = TCP_N_ERROR,
3183 .error_strings = tcp_error_strings,
3184 .n_next_nodes = TCP_INPUT_N_NEXT,
3187 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3188 foreach_tcp6_input_next
3191 .format_buffer = format_tcp_header,
3192 .format_trace = format_tcp_rx_trace,
3196 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3199 tcp_dispatch_table_init (tcp_main_t * tm)
3202 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3203 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3205 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3206 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3209 #define _(t,f,n,e) \
3211 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3212 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3215 /* SYNs for new connections -> tcp-listen. */
3216 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3217 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3218 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3219 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3221 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3222 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3223 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3224 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3225 /* SYN-ACK for a SYN */
3226 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3228 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3229 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3230 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3232 /* ACK for for established connection -> tcp-established. */
3233 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3234 /* FIN for for established connection -> tcp-established. */
3235 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3236 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3238 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3239 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3241 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3242 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3244 /* ACK or FIN-ACK to our FIN */
3245 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3246 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3248 /* FIN in reply to our FIN from the other side */
3249 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3250 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3251 /* FIN confirming that the peer (app) has closed */
3252 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3253 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3254 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3256 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3257 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3259 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3260 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3261 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3263 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3264 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3265 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3267 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3268 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3269 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3270 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3271 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3272 TCP_ERROR_CONNECTION_CLOSED);
3277 tcp_input_init (vlib_main_t * vm)
3279 clib_error_t *error = 0;
3280 tcp_main_t *tm = vnet_get_tcp_main ();
3282 if ((error = vlib_call_init_function (vm, tcp_init)))
3285 /* Initialize dispatch table. */
3286 tcp_dispatch_table_init (tm);
3291 VLIB_INIT_FUNCTION (tcp_input_init);
3294 * fd.io coding-style-patch-verification: ON
3297 * eval: (c-set-style "gnu")