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 tcp_cc_init_congestion (tcp_connection_t * tc)
942 tcp_fastrecovery_on (tc);
943 tc->snd_congestion = tc->snd_una_max;
944 tc->cwnd_acc_bytes = 0;
945 tc->cc_algo->congestion (tc);
946 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
950 tcp_cc_recovery_exit (tcp_connection_t * tc)
956 tc->snd_nxt = tc->snd_una_max;
957 tcp_recovery_off (tc);
958 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
962 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
964 tc->cc_algo->recovered (tc);
965 tc->snd_rxt_bytes = 0;
967 tc->snd_nxt = tc->snd_una_max;
968 tcp_fastrecovery_off (tc);
969 tcp_fastrecovery_1_smss_off (tc);
970 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
974 tcp_cc_congestion_undo (tcp_connection_t * tc)
976 tc->cwnd = tc->prev_cwnd;
977 tc->ssthresh = tc->prev_ssthresh;
978 tc->snd_nxt = tc->snd_una_max;
980 if (tcp_in_recovery (tc))
981 tcp_cc_recovery_exit (tc);
982 ASSERT (tc->rto_boff == 0);
983 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
984 /* TODO extend for fastrecovery */
988 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
990 return (tcp_in_recovery (tc) && tc->rto_boff == 1
992 && tcp_opts_tstamp (&tc->rcv_opts)
993 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
997 tcp_cc_recover (tcp_connection_t * tc)
999 ASSERT (tcp_in_cong_recovery (tc));
1000 if (tcp_cc_is_spurious_retransmit (tc))
1002 tcp_cc_congestion_undo (tc);
1006 if (tcp_in_recovery (tc))
1007 tcp_cc_recovery_exit (tc);
1008 else if (tcp_in_fastrecovery (tc))
1009 tcp_cc_fastrecovery_exit (tc);
1011 ASSERT (tc->rto_boff == 0);
1012 ASSERT (!tcp_in_cong_recovery (tc));
1013 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1018 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1020 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1022 /* Congestion avoidance */
1023 tc->cc_algo->rcv_ack (tc);
1024 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1026 /* If a cumulative ack, make sure dupacks is 0 */
1027 tc->rcv_dupacks = 0;
1029 /* When dupacks hits the threshold we only enter fast retransmit if
1030 * cumulative ack covers more than snd_congestion. Should snd_una
1031 * wrap this test may fail under otherwise valid circumstances.
1032 * Therefore, proactively update snd_congestion when wrap detected. */
1034 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1035 && seq_gt (tc->snd_congestion, tc->snd_una)))
1036 tc->snd_congestion = tc->snd_una - 1;
1040 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1042 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1046 tcp_should_fastrecover (tcp_connection_t * tc)
1048 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1049 || tcp_should_fastrecover_sack (tc));
1053 * One function to rule them all ... and in the darkness bind them
1056 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1061 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1062 * it account for the bytes that left the network.
1066 ASSERT (tc->snd_una != tc->snd_una_max
1067 || tc->sack_sb.last_sacked_bytes);
1071 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1073 ASSERT (tcp_in_fastrecovery (tc));
1074 /* Pure duplicate ack. If some data got acked, it's handled lower */
1075 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1078 else if (tcp_should_fastrecover (tc))
1080 /* Things are already bad */
1081 if (tcp_in_cong_recovery (tc))
1083 tc->rcv_dupacks = 0;
1084 goto partial_ack_test;
1087 /* If of of the two conditions lower hold, reset dupacks because
1088 * we're probably after timeout (RFC6582 heuristics).
1089 * If Cumulative ack does not cover more than congestion threshold,
1091 * 1) The following doesn't hold: The congestion window is greater
1092 * than SMSS bytes and the difference between highest_ack
1093 * and prev_highest_ack is at most 4*SMSS bytes
1094 * 2) Echoed timestamp in the last non-dup ack does not equal the
1097 if (seq_leq (tc->snd_una, tc->snd_congestion)
1098 && ((!(tc->cwnd > tc->snd_mss
1099 && tc->bytes_acked <= 4 * tc->snd_mss))
1100 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1102 tc->rcv_dupacks = 0;
1106 tcp_cc_init_congestion (tc);
1107 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1109 /* The first segment MUST be retransmitted */
1110 tcp_retransmit_first_unacked (tc);
1112 /* Post retransmit update cwnd to ssthresh and account for the
1113 * three segments that have left the network and should've been
1114 * buffered at the receiver XXX */
1115 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1116 ASSERT (tc->cwnd >= tc->snd_mss);
1118 /* If cwnd allows, send more data */
1119 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1121 scoreboard_init_high_rxt (&tc->sack_sb,
1122 tc->snd_una + tc->snd_mss);
1123 tcp_fast_retransmit_sack (tc);
1127 tcp_fast_retransmit_no_sack (tc);
1132 else if (!tc->bytes_acked
1133 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1135 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1144 if (!tc->bytes_acked)
1149 * Legitimate ACK. 1) See if we can exit recovery
1151 /* XXX limit this only to first partial ack? */
1152 tcp_retransmit_timer_update (tc);
1154 if (seq_geq (tc->snd_una, tc->snd_congestion))
1156 /* If spurious return, we've already updated everything */
1157 if (tcp_cc_recover (tc))
1159 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1163 tc->snd_nxt = tc->snd_una_max;
1165 /* Treat as congestion avoidance ack */
1166 tc->cc_algo->rcv_ack (tc);
1167 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1172 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1174 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1176 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1177 * reset dupacks to 0 */
1178 tc->rcv_dupacks = 0;
1180 tcp_retransmit_first_unacked (tc);
1182 /* Post RTO timeout don't try anything fancy */
1183 if (tcp_in_recovery (tc))
1186 /* Remove retransmitted bytes that have been delivered */
1187 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1188 >= tc->sack_sb.last_bytes_delivered
1189 || (tc->flags & TCP_CONN_FINSNT));
1191 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1193 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1194 * remove sacked bytes delivered */
1195 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1196 - tc->sack_sb.last_bytes_delivered;
1197 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1198 tc->snd_rxt_bytes -= rxt_delivered;
1202 /* Either all retransmitted holes have been acked, or we're
1203 * "in the blind" and retransmitting segment by segment */
1204 tc->snd_rxt_bytes = 0;
1207 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1210 * Since this was a partial ack, try to retransmit some more data
1212 tcp_fast_retransmit (tc);
1216 tcp_cc_init (tcp_connection_t * tc)
1218 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
1219 tc->cc_algo->init (tc);
1223 * Process incoming ACK
1226 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1227 tcp_header_t * th, u32 * next, u32 * error)
1229 u32 prev_snd_wnd, prev_snd_una;
1232 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1234 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1235 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1237 /* If we have outstanding data and this is within the window, accept it,
1238 * probably retransmit has timed out. Otherwise ACK segment and then
1240 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1242 tcp_make_ack (tc, b);
1243 *next = tcp_next_output (tc->c_is_ip4);
1244 *error = TCP_ERROR_ACK_INVALID;
1245 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1246 vnet_buffer (b)->tcp.ack_number);
1250 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1251 vnet_buffer (b)->tcp.ack_number);
1253 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1254 *error = TCP_ERROR_ACK_FUTURE;
1257 /* If old ACK, probably it's an old dupack */
1258 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1260 *error = TCP_ERROR_ACK_OLD;
1261 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1262 vnet_buffer (b)->tcp.ack_number);
1263 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1265 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
1266 tcp_cc_handle_event (tc, 1);
1268 /* Don't drop yet */
1273 * Looks okay, process feedback
1276 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1277 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1279 prev_snd_wnd = tc->snd_wnd;
1280 prev_snd_una = tc->snd_una;
1281 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1282 vnet_buffer (b)->tcp.ack_number,
1283 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1284 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1285 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1286 tcp_validate_txf_size (tc, tc->bytes_acked);
1288 if (tc->bytes_acked)
1289 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1291 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1294 * Check if we have congestion event
1297 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1299 tcp_cc_handle_event (tc, is_dack);
1300 if (!tcp_in_cong_recovery (tc))
1302 *error = TCP_ERROR_ACK_DUP;
1303 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1304 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1308 * Update congestion control (slow start/congestion avoidance)
1310 tcp_cc_update (tc, b);
1311 *error = TCP_ERROR_ACK_OK;
1316 tcp_sack_vector_is_sane (sack_block_t * sacks)
1319 for (i = 1; i < vec_len (sacks); i++)
1321 if (sacks[i - 1].end == sacks[i].start)
1328 * Build SACK list as per RFC2018.
1330 * Makes sure the first block contains the segment that generated the current
1331 * ACK and the following ones are the ones most recently reported in SACK
1334 * @param tc TCP connection for which the SACK list is updated
1335 * @param start Start sequence number of the newest SACK block
1336 * @param end End sequence of the newest SACK block
1339 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1341 sack_block_t *new_list = 0, *block = 0;
1344 /* If the first segment is ooo add it to the list. Last write might've moved
1345 * rcv_nxt over the first segment. */
1346 if (seq_lt (tc->rcv_nxt, start))
1348 vec_add2 (new_list, block, 1);
1349 block->start = start;
1353 /* Find the blocks still worth keeping. */
1354 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1356 /* Discard if rcv_nxt advanced beyond current block */
1357 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1360 /* Merge or drop if segment overlapped by the new segment */
1361 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1362 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1364 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1365 new_list[0].start = tc->snd_sacks[i].start;
1366 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1367 new_list[0].end = tc->snd_sacks[i].end;
1371 /* Save to new SACK list if we have space. */
1372 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1374 vec_add1 (new_list, tc->snd_sacks[i]);
1378 clib_warning ("sack discarded");
1382 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1384 /* Replace old vector with new one */
1385 vec_free (tc->snd_sacks);
1386 tc->snd_sacks = new_list;
1388 /* Segments should not 'touch' */
1389 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1392 /** Enqueue data for delivery to application */
1394 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1397 int written, error = TCP_ERROR_ENQUEUED;
1399 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1401 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1402 1 /* queue event */ , 1);
1404 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1406 /* Update rcv_nxt */
1407 if (PREDICT_TRUE (written == data_len))
1409 tc->rcv_nxt += written;
1411 /* If more data written than expected, account for out-of-order bytes. */
1412 else if (written > data_len)
1414 tc->rcv_nxt += written;
1416 /* Send ACK confirming the update */
1417 tc->flags |= TCP_CONN_SNDACK;
1419 else if (written > 0)
1421 /* We've written something but FIFO is probably full now */
1422 tc->rcv_nxt += written;
1424 /* Depending on how fast the app is, all remaining buffers in burst will
1425 * not be enqueued. Inform peer */
1426 tc->flags |= TCP_CONN_SNDACK;
1428 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1432 tc->flags |= TCP_CONN_SNDACK;
1433 return TCP_ERROR_FIFO_FULL;
1436 /* Update SACK list if need be */
1437 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1439 /* Remove SACK blocks that have been delivered */
1440 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1446 /** Enqueue out-of-order data */
1448 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1451 stream_session_t *s0;
1454 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1457 /* Enqueue out-of-order data with relative offset */
1458 rv = session_enqueue_stream_connection (&tc->connection, b,
1459 vnet_buffer (b)->tcp.seq_number -
1460 tc->rcv_nxt, 0 /* queue event */ ,
1463 /* Nothing written */
1466 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1467 return TCP_ERROR_FIFO_FULL;
1470 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1472 /* Update SACK list if in use */
1473 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1475 ooo_segment_t *newest;
1478 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1480 /* Get the newest segment from the fifo */
1481 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1484 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1485 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1486 start = tc->rcv_nxt + offset;
1487 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1488 tcp_update_sack_list (tc, start, end);
1489 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1493 return TCP_ERROR_ENQUEUED_OOO;
1497 * Check if ACK could be delayed. If ack can be delayed, it should return
1498 * true for a full frame. If we're always acking return 0.
1501 tcp_can_delack (tcp_connection_t * tc)
1503 /* Send ack if ... */
1505 /* just sent a rcv wnd 0 */
1506 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1507 /* constrained to send ack */
1508 || (tc->flags & TCP_CONN_SNDACK) != 0
1509 /* we're almost out of tx wnd */
1510 || tcp_available_snd_space (tc) < 4 * tc->snd_mss)
1517 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1519 u32 discard, first = b->current_length;
1520 vlib_main_t *vm = vlib_get_main ();
1522 /* Handle multi-buffer segments */
1523 if (n_bytes_to_drop > b->current_length)
1525 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1529 discard = clib_min (n_bytes_to_drop, b->current_length);
1530 vlib_buffer_advance (b, discard);
1531 b = vlib_get_buffer (vm, b->next_buffer);
1532 n_bytes_to_drop -= discard;
1534 while (n_bytes_to_drop);
1535 if (n_bytes_to_drop > first)
1536 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1539 vlib_buffer_advance (b, n_bytes_to_drop);
1540 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1545 * Receive buffer for connection and handle acks
1547 * It handles both in order or out-of-order data.
1550 tcp_segment_rcv (tcp_connection_t * tc, vlib_buffer_t * b, u32 * next0)
1552 u32 error, n_bytes_to_drop, n_data_bytes;
1554 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1555 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1556 ASSERT (n_data_bytes);
1558 /* Handle out-of-order data */
1559 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1561 /* Old sequence numbers allowed through because they overlapped
1563 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1565 /* Completely in the past (possible retransmit). Ack
1566 * retransmissions since we may not have any data to send */
1567 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1569 tcp_make_ack (tc, b);
1570 error = TCP_ERROR_SEGMENT_OLD;
1571 *next0 = tcp_next_output (tc->c_is_ip4);
1575 /* Chop off the bytes in the past and see if what is left
1576 * can be enqueued in order */
1577 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1578 n_data_bytes -= n_bytes_to_drop;
1579 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1580 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1582 error = TCP_ERROR_SEGMENT_OLD;
1583 *next0 = tcp_next_drop (tc->c_is_ip4);
1589 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1590 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1591 *next0 = tcp_next_output (tc->c_is_ip4);
1592 tcp_make_ack (tc, b);
1593 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1594 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1600 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1601 * segments can be enqueued after fifo tail offset changes. */
1602 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1603 if (tcp_can_delack (tc))
1605 *next0 = tcp_next_drop (tc->c_is_ip4);
1606 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1607 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1611 *next0 = tcp_next_output (tc->c_is_ip4);
1612 tcp_make_ack (tc, b);
1620 tcp_header_t tcp_header;
1621 tcp_connection_t tcp_connection;
1625 format_tcp_rx_trace (u8 * s, va_list * args)
1627 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1628 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1629 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1630 u32 indent = format_get_indent (s);
1632 s = format (s, "%U\n%U%U",
1633 format_tcp_header, &t->tcp_header, 128,
1634 format_white_space, indent,
1635 format_tcp_connection, &t->tcp_connection, 1);
1641 format_tcp_rx_trace_short (u8 * s, va_list * args)
1643 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1644 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1645 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1647 s = format (s, "%d -> %d (%U)",
1648 clib_net_to_host_u16 (t->tcp_header.src_port),
1649 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1650 t->tcp_connection.state);
1656 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1657 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1661 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1665 th0 = tcp_buffer_hdr (b0);
1667 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1671 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1672 u8 is_ip4, u32 evt, u32 val)
1675 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1677 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1680 #define tcp_maybe_inc_counter(node_id, err, count) \
1682 if (next0 != tcp_next_drop (is_ip4)) \
1683 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1684 tcp6_##node_id##_node.index, is_ip4, err, \
1687 #define tcp_inc_counter(node_id, err, count) \
1688 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1689 tcp6_##node_id##_node.index, is_ip4, \
1691 #define tcp_maybe_inc_err_counter(cnts, err) \
1693 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
1695 #define tcp_inc_err_counter(cnts, err, val) \
1699 #define tcp_store_err_counters(node_id, cnts) \
1702 for (i = 0; i < TCP_N_ERROR; i++) \
1704 tcp_inc_counter(node_id, i, cnts[i]); \
1709 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1710 vlib_frame_t * from_frame, int is_ip4)
1712 u32 my_thread_index = vm->thread_index, errors = 0;
1713 u32 n_left_from, next_index, *from, *to_next;
1714 u16 err_counters[TCP_N_ERROR] = { 0 };
1717 from = vlib_frame_vector_args (from_frame);
1718 n_left_from = from_frame->n_vectors;
1719 next_index = node->cached_next_index;
1721 while (n_left_from > 0)
1725 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1726 while (n_left_from > 0 && n_left_to_next > 0)
1730 tcp_header_t *th0 = 0;
1731 tcp_connection_t *tc0;
1732 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ACK_OK;
1734 if (n_left_from > 1)
1737 pb = vlib_get_buffer (vm, from[1]);
1738 vlib_prefetch_buffer_header (pb, LOAD);
1739 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
1747 n_left_to_next -= 1;
1749 b0 = vlib_get_buffer (vm, bi0);
1750 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1753 if (PREDICT_FALSE (tc0 == 0))
1755 error0 = TCP_ERROR_INVALID_CONNECTION;
1759 th0 = tcp_buffer_hdr (b0);
1760 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1761 * dangling reference. */
1762 is_fin = tcp_is_fin (th0);
1764 /* SYNs, FINs and data consume sequence numbers */
1765 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1766 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1768 /* TODO header prediction fast path */
1770 /* 1-4: check SEQ, RST, SYN */
1771 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0,
1774 tcp_maybe_inc_err_counter (err_counters, error0);
1775 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1776 vnet_buffer (b0)->tcp.seq_number,
1777 vnet_buffer (b0)->tcp.seq_end);
1781 /* 5: check the ACK field */
1782 if (PREDICT_FALSE (tcp_rcv_ack (tc0, b0, th0, &next0, &error0)))
1784 tcp_maybe_inc_err_counter (err_counters, error0);
1788 /* 6: check the URG bit TODO */
1790 /* 7: process the segment text */
1791 if (vnet_buffer (b0)->tcp.data_len)
1793 error0 = tcp_segment_rcv (tc0, b0, &next0);
1794 tcp_maybe_inc_err_counter (err_counters, error0);
1797 /* 8: check the FIN bit */
1798 if (PREDICT_FALSE (is_fin))
1800 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1801 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1802 /* Account for the FIN if nothing else was received */
1803 if (vnet_buffer (b0)->tcp.data_len == 0)
1805 tcp_make_ack (tc0, b0);
1806 next0 = tcp_next_output (tc0->c_is_ip4);
1807 tc0->state = TCP_STATE_CLOSE_WAIT;
1808 stream_session_disconnect_notify (&tc0->connection);
1809 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1810 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1811 tcp_inc_err_counter (err_counters, TCP_ERROR_FIN_RCVD, 1);
1815 b0->error = node->errors[error0];
1816 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1818 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0,
1820 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1823 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1824 n_left_to_next, bi0, next0);
1827 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1830 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
1832 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
1833 tcp_store_err_counters (established, err_counters);
1834 tcp_flush_frame_to_output (vm, my_thread_index, is_ip4);
1835 return from_frame->n_vectors;
1839 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1840 vlib_frame_t * from_frame)
1842 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1846 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1847 vlib_frame_t * from_frame)
1849 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1853 VLIB_REGISTER_NODE (tcp4_established_node) =
1855 .function = tcp4_established,
1856 .name = "tcp4-established",
1857 /* Takes a vector of packets. */
1858 .vector_size = sizeof (u32),
1859 .n_errors = TCP_N_ERROR,
1860 .error_strings = tcp_error_strings,
1861 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1864 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1865 foreach_tcp_state_next
1868 .format_trace = format_tcp_rx_trace_short,
1872 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1875 VLIB_REGISTER_NODE (tcp6_established_node) =
1877 .function = tcp6_established,
1878 .name = "tcp6-established",
1879 /* Takes a vector of packets. */
1880 .vector_size = sizeof (u32),
1881 .n_errors = TCP_N_ERROR,
1882 .error_strings = tcp_error_strings,
1883 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1886 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1887 foreach_tcp_state_next
1890 .format_trace = format_tcp_rx_trace_short,
1895 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1897 vlib_node_registration_t tcp4_syn_sent_node;
1898 vlib_node_registration_t tcp6_syn_sent_node;
1901 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
1903 transport_connection_t *tmp = 0;
1910 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
1913 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
1914 && (tc->state == TCP_STATE_LISTEN
1915 || tc->c_rmt_port == hdr->src_port));
1919 handle = session_lookup_half_open_handle (&tc->connection);
1920 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
1921 tc->c_proto, tc->c_is_ip4);
1925 if (tmp->lcl_port == hdr->dst_port
1926 && tmp->rmt_port == hdr->src_port)
1928 TCP_DBG ("half-open is valid!");
1936 * Lookup transport connection
1938 static tcp_connection_t *
1939 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
1943 transport_connection_t *tconn;
1944 tcp_connection_t *tc;
1949 ip4 = vlib_buffer_get_current (b);
1950 tcp = ip4_next_header (ip4);
1951 tconn = session_lookup_connection_wt4 (fib_index,
1956 TRANSPORT_PROTO_TCP,
1957 thread_index, &is_filtered);
1958 tc = tcp_get_connection_from_transport (tconn);
1959 ASSERT (tcp_lookup_is_valid (tc, tcp));
1964 ip6 = vlib_buffer_get_current (b);
1965 tcp = ip6_next_header (ip6);
1966 tconn = session_lookup_connection_wt6 (fib_index,
1971 TRANSPORT_PROTO_TCP,
1972 thread_index, &is_filtered);
1973 tc = tcp_get_connection_from_transport (tconn);
1974 ASSERT (tcp_lookup_is_valid (tc, tcp));
1980 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1981 vlib_frame_t * from_frame, int is_ip4)
1983 tcp_main_t *tm = vnet_get_tcp_main ();
1984 u32 n_left_from, next_index, *from, *to_next;
1985 u32 my_thread_index = vm->thread_index, errors = 0;
1987 from = vlib_frame_vector_args (from_frame);
1988 n_left_from = from_frame->n_vectors;
1990 next_index = node->cached_next_index;
1992 while (n_left_from > 0)
1996 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1998 while (n_left_from > 0 && n_left_to_next > 0)
2000 u32 bi0, ack0, seq0;
2003 tcp_header_t *tcp0 = 0;
2004 tcp_connection_t *tc0;
2005 tcp_connection_t *new_tc0;
2006 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
2013 n_left_to_next -= 1;
2015 b0 = vlib_get_buffer (vm, bi0);
2017 tcp_half_open_connection_get (vnet_buffer (b0)->
2018 tcp.connection_index);
2019 if (PREDICT_FALSE (tc0 == 0))
2021 error0 = TCP_ERROR_INVALID_CONNECTION;
2025 /* Half-open completed recently but the connection was't removed
2026 * yet by the owning thread */
2027 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2029 /* Make sure the connection actually exists */
2030 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2031 my_thread_index, is_ip4));
2035 ack0 = vnet_buffer (b0)->tcp.ack_number;
2036 seq0 = vnet_buffer (b0)->tcp.seq_number;
2037 tcp0 = tcp_buffer_hdr (b0);
2039 /* Crude check to see if the connection handle does not match
2040 * the packet. Probably connection just switched to established */
2041 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2042 || tcp0->src_port != tc0->c_rmt_port))
2046 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
2049 /* SYNs, FINs and data consume sequence numbers */
2050 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
2051 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
2054 * 1. check the ACK bit
2058 * If the ACK bit is set
2059 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2060 * the RST bit is set, if so drop the segment and return)
2061 * <SEQ=SEG.ACK><CTL=RST>
2062 * and discard the segment. Return.
2063 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2067 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2069 clib_warning ("ack not in rcv wnd");
2070 if (!tcp_rst (tcp0))
2071 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2075 /* Make sure ACK is valid */
2076 if (seq_gt (tc0->snd_una, ack0))
2078 clib_warning ("ack invalid");
2084 * 2. check the RST bit
2089 /* If ACK is acceptable, signal client that peer is not
2090 * willing to accept connection and drop connection*/
2092 tcp_connection_reset (tc0);
2097 * 3. check the security and precedence (skipped)
2101 * 4. check the SYN bit
2104 /* No SYN flag. Drop. */
2105 if (!tcp_syn (tcp0))
2107 clib_warning ("not synack");
2112 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2114 clib_warning ("options parse fail");
2118 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2119 * current thread pool. */
2120 pool_get (tm->connections[my_thread_index], new_tc0);
2121 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2122 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2123 new_tc0->c_thread_index = my_thread_index;
2124 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2125 new_tc0->irs = seq0;
2126 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2127 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2128 TCP_TIMER_HANDLE_INVALID;
2130 /* If this is not the owning thread, wait for syn retransmit to
2131 * expire and cleanup then */
2132 if (tcp_half_open_connection_cleanup (tc0))
2133 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2135 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2137 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2138 new_tc0->tsval_recent_age = tcp_time_now ();
2141 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2142 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2144 /* RFC1323: SYN and SYN-ACK wnd not scaled */
2145 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
2146 new_tc0->snd_wl1 = seq0;
2147 new_tc0->snd_wl2 = ack0;
2149 tcp_connection_init_vars (new_tc0);
2151 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2152 if (PREDICT_TRUE (tcp_ack (tcp0)))
2154 /* Our SYN is ACKed: we have iss < ack = snd_una */
2156 /* TODO Dequeue acknowledged segments if we support Fast Open */
2157 new_tc0->snd_una = ack0;
2158 new_tc0->state = TCP_STATE_ESTABLISHED;
2160 /* Make sure las is initialized for the wnd computation */
2161 new_tc0->rcv_las = new_tc0->rcv_nxt;
2163 /* Notify app that we have connection. If session layer can't
2164 * allocate session send reset */
2165 if (session_stream_connect_notify (&new_tc0->connection, 0))
2167 clib_warning ("connect notify fail");
2168 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2169 tcp_connection_cleanup (new_tc0);
2173 /* Make sure after data segment processing ACK is sent */
2174 new_tc0->flags |= TCP_CONN_SNDACK;
2176 /* Update rtt with the syn-ack sample */
2177 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2178 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2180 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2183 new_tc0->state = TCP_STATE_SYN_RCVD;
2185 /* Notify app that we have connection */
2186 if (session_stream_connect_notify (&new_tc0->connection, 0))
2188 tcp_connection_cleanup (new_tc0);
2189 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2190 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2195 tcp_init_snd_vars (tc0);
2196 tcp_make_synack (new_tc0, b0);
2197 next0 = tcp_next_output (is_ip4);
2202 /* Read data, if any */
2203 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2205 clib_warning ("rcvd data in syn-sent");
2206 error0 = tcp_segment_rcv (new_tc0, b0, &next0);
2207 if (error0 == TCP_ERROR_ACK_OK)
2208 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2209 tcp_maybe_inc_counter (syn_sent, error0, 1);
2213 tcp_make_ack (new_tc0, b0);
2214 next0 = tcp_next_output (new_tc0->c_is_ip4);
2219 b0->error = error0 ? node->errors[error0] : 0;
2221 ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2223 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2224 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2225 clib_memcpy (&t0->tcp_connection, tc0,
2226 sizeof (t0->tcp_connection));
2229 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2230 n_left_to_next, bi0, next0);
2233 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2236 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2238 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2239 return from_frame->n_vectors;
2243 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2244 vlib_frame_t * from_frame)
2246 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2250 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2251 vlib_frame_t * from_frame)
2253 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2257 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2259 .function = tcp4_syn_sent,
2260 .name = "tcp4-syn-sent",
2261 /* Takes a vector of packets. */
2262 .vector_size = sizeof (u32),
2263 .n_errors = TCP_N_ERROR,
2264 .error_strings = tcp_error_strings,
2265 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2268 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2269 foreach_tcp_state_next
2272 .format_trace = format_tcp_rx_trace_short,
2276 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2279 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2281 .function = tcp6_syn_sent_rcv,
2282 .name = "tcp6-syn-sent",
2283 /* Takes a vector of packets. */
2284 .vector_size = sizeof (u32),
2285 .n_errors = TCP_N_ERROR,
2286 .error_strings = tcp_error_strings,
2287 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2290 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2291 foreach_tcp_state_next
2294 .format_trace = format_tcp_rx_trace_short,
2298 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2300 vlib_node_registration_t tcp4_rcv_process_node;
2301 vlib_node_registration_t tcp6_rcv_process_node;
2304 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2305 * as per RFC793 p. 64
2308 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2309 vlib_frame_t * from_frame, int is_ip4)
2311 u32 n_left_from, next_index, *from, *to_next, n_fins = 0;
2312 u32 my_thread_index = vm->thread_index, errors = 0;
2314 from = vlib_frame_vector_args (from_frame);
2315 n_left_from = from_frame->n_vectors;
2316 next_index = node->cached_next_index;
2318 while (n_left_from > 0)
2322 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2324 while (n_left_from > 0 && n_left_to_next > 0)
2328 tcp_header_t *tcp0 = 0;
2329 tcp_connection_t *tc0;
2330 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_NONE;
2338 n_left_to_next -= 1;
2340 b0 = vlib_get_buffer (vm, bi0);
2341 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2343 if (PREDICT_FALSE (tc0 == 0))
2345 error0 = TCP_ERROR_INVALID_CONNECTION;
2349 tcp0 = tcp_buffer_hdr (b0);
2350 is_fin0 = tcp_is_fin (tcp0);
2352 /* SYNs, FINs and data consume sequence numbers */
2353 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2354 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2358 tcp_connection_t *tmp;
2359 tmp = tcp_lookup_connection (tc0->c_fib_index, b0,
2360 my_thread_index, is_ip4);
2361 if (tmp->state != tc0->state)
2363 clib_warning ("state changed");
2369 * Special treatment for CLOSED
2371 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2373 error0 = TCP_ERROR_CONNECTION_CLOSED;
2378 * For all other states (except LISTEN)
2381 /* 1-4: check SEQ, RST, SYN */
2382 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2385 tcp_maybe_inc_counter (rcv_process, error0, 1);
2389 /* 5: check the ACK field */
2392 case TCP_STATE_SYN_RCVD:
2394 * If the segment acknowledgment is not acceptable, form a
2396 * <SEQ=SEG.ACK><CTL=RST>
2399 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2401 TCP_DBG ("connection not accepted");
2402 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2403 error0 = TCP_ERROR_ACK_INVALID;
2407 /* Update rtt and rto */
2408 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2410 /* Switch state to ESTABLISHED */
2411 tc0->state = TCP_STATE_ESTABLISHED;
2412 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2414 /* Initialize session variables */
2415 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2416 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2417 << tc0->rcv_opts.wscale;
2418 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2419 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2421 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2422 tcp_retransmit_timer_reset (tc0);
2423 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2424 stream_session_accept_notify (&tc0->connection);
2425 error0 = TCP_ERROR_ACK_OK;
2427 case TCP_STATE_ESTABLISHED:
2428 /* We can get packets in established state here because they
2429 * were enqueued before state change */
2430 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2432 tcp_maybe_inc_counter (rcv_process, error0, 1);
2437 case TCP_STATE_FIN_WAIT_1:
2438 /* In addition to the processing for the ESTABLISHED state, if
2439 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2440 * continue processing in that state. */
2441 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2443 tcp_maybe_inc_counter (rcv_process, error0, 1);
2447 /* Still have to send the FIN */
2448 if (tc0->flags & TCP_CONN_FINPNDG)
2450 /* TX fifo finally drained */
2451 if (!stream_session_tx_fifo_max_dequeue (&tc0->connection))
2454 /* If FIN is ACKed */
2455 else if (tc0->snd_una == tc0->snd_una_max)
2457 tc0->state = TCP_STATE_FIN_WAIT_2;
2458 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2460 /* Stop all retransmit timers because we have nothing more
2461 * to send. Enable waitclose though because we're willing to
2462 * wait for peer's FIN but not indefinitely. */
2463 tcp_connection_timers_reset (tc0);
2464 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2467 case TCP_STATE_FIN_WAIT_2:
2468 /* In addition to the processing for the ESTABLISHED state, if
2469 * the retransmission queue is empty, the user's CLOSE can be
2470 * acknowledged ("ok") but do not delete the TCB. */
2471 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2473 tcp_maybe_inc_counter (rcv_process, error0, 1);
2477 case TCP_STATE_CLOSE_WAIT:
2478 /* Do the same processing as for the ESTABLISHED state. */
2479 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2481 tcp_maybe_inc_counter (rcv_process, error0, 1);
2485 case TCP_STATE_CLOSING:
2486 /* In addition to the processing for the ESTABLISHED state, if
2487 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2488 * otherwise ignore the segment. */
2489 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2491 tcp_maybe_inc_counter (rcv_process, error0, 1);
2495 tc0->state = TCP_STATE_TIME_WAIT;
2496 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2497 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2501 case TCP_STATE_LAST_ACK:
2502 /* The only thing that [should] arrive in this state is an
2503 * acknowledgment of our FIN. If our FIN is now acknowledged,
2504 * delete the TCB, enter the CLOSED state, and return. */
2506 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2508 error0 = TCP_ERROR_ACK_INVALID;
2511 error0 = TCP_ERROR_ACK_OK;
2512 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2513 /* Apparently our ACK for the peer's FIN was lost */
2514 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2520 tc0->state = TCP_STATE_CLOSED;
2521 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2522 tcp_connection_timers_reset (tc0);
2524 /* Don't delete the connection/session yet. Instead, wait a
2525 * reasonable amount of time until the pipes are cleared. In
2526 * particular, this makes sure that we won't have dead sessions
2527 * when processing events on the tx path */
2528 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2533 case TCP_STATE_TIME_WAIT:
2534 /* The only thing that can arrive in this state is a
2535 * retransmission of the remote FIN. Acknowledge it, and restart
2536 * the 2 MSL timeout. */
2538 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2540 tcp_maybe_inc_counter (rcv_process, error0, 1);
2544 tcp_make_ack (tc0, b0);
2545 next0 = tcp_next_output (is_ip4);
2546 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2554 /* 6: check the URG bit TODO */
2556 /* 7: process the segment text */
2559 case TCP_STATE_ESTABLISHED:
2560 case TCP_STATE_FIN_WAIT_1:
2561 case TCP_STATE_FIN_WAIT_2:
2562 if (vnet_buffer (b0)->tcp.data_len)
2564 error0 = tcp_segment_rcv (tc0, b0, &next0);
2565 tcp_maybe_inc_counter (rcv_process, error0, 1);
2570 case TCP_STATE_CLOSE_WAIT:
2571 case TCP_STATE_CLOSING:
2572 case TCP_STATE_LAST_ACK:
2573 case TCP_STATE_TIME_WAIT:
2574 /* This should not occur, since a FIN has been received from the
2575 * remote side. Ignore the segment text. */
2579 /* 8: check the FIN bit */
2585 case TCP_STATE_ESTABLISHED:
2586 case TCP_STATE_SYN_RCVD:
2587 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2588 tcp_connection_timers_reset (tc0);
2589 tcp_make_fin (tc0, b0);
2591 next0 = tcp_next_output (tc0->c_is_ip4);
2592 stream_session_disconnect_notify (&tc0->connection);
2593 tc0->state = TCP_STATE_CLOSE_WAIT;
2594 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2596 case TCP_STATE_CLOSE_WAIT:
2597 case TCP_STATE_CLOSING:
2598 case TCP_STATE_LAST_ACK:
2601 case TCP_STATE_FIN_WAIT_1:
2602 tc0->state = TCP_STATE_CLOSING;
2603 tcp_make_ack (tc0, b0);
2604 next0 = tcp_next_output (is_ip4);
2605 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2606 /* Wait for ACK but not forever */
2607 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2609 case TCP_STATE_FIN_WAIT_2:
2610 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2611 tc0->state = TCP_STATE_TIME_WAIT;
2612 tcp_connection_timers_reset (tc0);
2613 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2614 tcp_make_ack (tc0, b0);
2615 next0 = tcp_next_output (is_ip4);
2616 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2618 case TCP_STATE_TIME_WAIT:
2619 /* Remain in the TIME-WAIT state. Restart the time-wait
2622 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2625 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2629 b0->error = error0 ? node->errors[error0] : 0;
2631 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2633 tcp_rx_trace_t *t0 =
2634 vlib_add_trace (vm, node, b0, sizeof (*t0));
2635 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2638 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2639 n_left_to_next, bi0, next0);
2642 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2645 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2647 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2648 tcp_inc_counter (rcv_process, TCP_ERROR_FIN_RCVD, n_fins);
2649 return from_frame->n_vectors;
2653 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2654 vlib_frame_t * from_frame)
2656 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2660 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2661 vlib_frame_t * from_frame)
2663 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2667 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2669 .function = tcp4_rcv_process,
2670 .name = "tcp4-rcv-process",
2671 /* Takes a vector of packets. */
2672 .vector_size = sizeof (u32),
2673 .n_errors = TCP_N_ERROR,
2674 .error_strings = tcp_error_strings,
2675 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2678 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2679 foreach_tcp_state_next
2682 .format_trace = format_tcp_rx_trace_short,
2686 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2689 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2691 .function = tcp6_rcv_process,
2692 .name = "tcp6-rcv-process",
2693 /* Takes a vector of packets. */
2694 .vector_size = sizeof (u32),
2695 .n_errors = TCP_N_ERROR,
2696 .error_strings = tcp_error_strings,
2697 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2700 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2701 foreach_tcp_state_next
2704 .format_trace = format_tcp_rx_trace_short,
2708 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2710 vlib_node_registration_t tcp4_listen_node;
2711 vlib_node_registration_t tcp6_listen_node;
2714 * LISTEN state processing as per RFC 793 p. 65
2717 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2718 vlib_frame_t * from_frame, int is_ip4)
2720 u32 n_left_from, next_index, *from, *to_next, n_syns = 0;
2721 u32 my_thread_index = vm->thread_index;
2723 from = vlib_frame_vector_args (from_frame);
2724 n_left_from = from_frame->n_vectors;
2726 next_index = node->cached_next_index;
2728 while (n_left_from > 0)
2732 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2734 while (n_left_from > 0 && n_left_to_next > 0)
2739 tcp_header_t *th0 = 0;
2740 tcp_connection_t *lc0;
2743 tcp_connection_t *child0;
2744 u32 error0 = TCP_ERROR_NONE, next0 = tcp_next_drop (is_ip4);
2751 n_left_to_next -= 1;
2753 b0 = vlib_get_buffer (vm, bi0);
2754 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2758 ip40 = vlib_buffer_get_current (b0);
2759 th0 = ip4_next_header (ip40);
2763 ip60 = vlib_buffer_get_current (b0);
2764 th0 = ip6_next_header (ip60);
2767 /* Create child session. For syn-flood protection use filter */
2769 /* 1. first check for an RST: handled in dispatch */
2770 /* if (tcp_rst (th0))
2773 /* 2. second check for an ACK: handled in dispatch */
2774 /* if (tcp_ack (th0))
2776 tcp_send_reset (b0, is_ip4);
2780 /* 3. check for a SYN (did that already) */
2782 /* Make sure connection wasn't just created */
2783 child0 = tcp_lookup_connection (lc0->c_fib_index, b0,
2784 my_thread_index, is_ip4);
2785 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
2787 error0 = TCP_ERROR_CREATE_EXISTS;
2791 /* Create child session and send SYN-ACK */
2792 child0 = tcp_connection_new (my_thread_index);
2793 child0->c_lcl_port = th0->dst_port;
2794 child0->c_rmt_port = th0->src_port;
2795 child0->c_is_ip4 = is_ip4;
2796 child0->state = TCP_STATE_SYN_RCVD;
2797 child0->c_fib_index = lc0->c_fib_index;
2801 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2802 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2806 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2807 sizeof (ip6_address_t));
2808 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2809 sizeof (ip6_address_t));
2812 if (tcp_options_parse (th0, &child0->rcv_opts))
2814 clib_warning ("options parse fail");
2818 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2819 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2820 child0->rcv_las = child0->rcv_nxt;
2822 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2823 * segments are used to initialize PAWS. */
2824 if (tcp_opts_tstamp (&child0->rcv_opts))
2826 child0->tsval_recent = child0->rcv_opts.tsval;
2827 child0->tsval_recent_age = tcp_time_now ();
2830 if (tcp_opts_wscale (&child0->rcv_opts))
2831 child0->snd_wscale = child0->rcv_opts.wscale;
2833 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2834 << child0->snd_wscale;
2835 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2836 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2838 tcp_connection_init_vars (child0);
2839 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
2841 if (stream_session_accept (&child0->connection, lc0->c_s_index,
2844 clib_warning ("session accept fail");
2845 tcp_connection_cleanup (child0);
2846 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2850 /* Reuse buffer to make syn-ack and send */
2851 tcp_make_synack (child0, b0);
2852 next0 = tcp_next_output (is_ip4);
2853 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
2856 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2858 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2859 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2860 clib_memcpy (&t0->tcp_connection, lc0,
2861 sizeof (t0->tcp_connection));
2864 n_syns += (error0 == TCP_ERROR_NONE);
2865 b0->error = node->errors[error0];
2867 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2868 n_left_to_next, bi0, next0);
2871 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2874 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
2875 return from_frame->n_vectors;
2879 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2880 vlib_frame_t * from_frame)
2882 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2886 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2887 vlib_frame_t * from_frame)
2889 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2893 VLIB_REGISTER_NODE (tcp4_listen_node) =
2895 .function = tcp4_listen,
2896 .name = "tcp4-listen",
2897 /* Takes a vector of packets. */
2898 .vector_size = sizeof (u32),
2899 .n_errors = TCP_N_ERROR,
2900 .error_strings = tcp_error_strings,
2901 .n_next_nodes = TCP_LISTEN_N_NEXT,
2904 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2905 foreach_tcp_state_next
2908 .format_trace = format_tcp_rx_trace_short,
2912 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2915 VLIB_REGISTER_NODE (tcp6_listen_node) =
2917 .function = tcp6_listen,
2918 .name = "tcp6-listen",
2919 /* Takes a vector of packets. */
2920 .vector_size = sizeof (u32),
2921 .n_errors = TCP_N_ERROR,
2922 .error_strings = tcp_error_strings,
2923 .n_next_nodes = TCP_LISTEN_N_NEXT,
2926 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2927 foreach_tcp_state_next
2930 .format_trace = format_tcp_rx_trace_short,
2934 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2936 vlib_node_registration_t tcp4_input_node;
2937 vlib_node_registration_t tcp6_input_node;
2939 typedef enum _tcp_input_next
2941 TCP_INPUT_NEXT_DROP,
2942 TCP_INPUT_NEXT_LISTEN,
2943 TCP_INPUT_NEXT_RCV_PROCESS,
2944 TCP_INPUT_NEXT_SYN_SENT,
2945 TCP_INPUT_NEXT_ESTABLISHED,
2946 TCP_INPUT_NEXT_RESET,
2947 TCP_INPUT_NEXT_PUNT,
2951 #define foreach_tcp4_input_next \
2952 _ (DROP, "ip4-drop") \
2953 _ (LISTEN, "tcp4-listen") \
2954 _ (RCV_PROCESS, "tcp4-rcv-process") \
2955 _ (SYN_SENT, "tcp4-syn-sent") \
2956 _ (ESTABLISHED, "tcp4-established") \
2957 _ (RESET, "tcp4-reset") \
2958 _ (PUNT, "ip4-punt")
2960 #define foreach_tcp6_input_next \
2961 _ (DROP, "ip6-drop") \
2962 _ (LISTEN, "tcp6-listen") \
2963 _ (RCV_PROCESS, "tcp6-rcv-process") \
2964 _ (SYN_SENT, "tcp6-syn-sent") \
2965 _ (ESTABLISHED, "tcp6-established") \
2966 _ (RESET, "tcp6-reset") \
2967 _ (PUNT, "ip6-punt")
2969 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2972 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2973 vlib_frame_t * from_frame, int is_ip4)
2975 u32 n_left_from, next_index, *from, *to_next;
2976 u32 my_thread_index = vm->thread_index;
2977 tcp_main_t *tm = vnet_get_tcp_main ();
2979 from = vlib_frame_vector_args (from_frame);
2980 n_left_from = from_frame->n_vectors;
2981 next_index = node->cached_next_index;
2982 tcp_set_time_now (my_thread_index);
2984 while (n_left_from > 0)
2988 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2990 while (n_left_from > 0 && n_left_to_next > 0)
2992 int n_advance_bytes0, n_data_bytes0;
2993 u32 bi0, fib_index0;
2995 tcp_header_t *tcp0 = 0;
2996 tcp_connection_t *tc0;
2997 transport_connection_t *tconn;
3000 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
3001 u8 flags0, is_filtered = 0;
3008 n_left_to_next -= 1;
3010 b0 = vlib_get_buffer (vm, bi0);
3011 vnet_buffer (b0)->tcp.flags = 0;
3012 fib_index0 = vnet_buffer (b0)->ip.fib_index;
3014 /* Checksum computed by ipx_local no need to compute again */
3018 ip40 = vlib_buffer_get_current (b0);
3019 tcp0 = ip4_next_header (ip40);
3020 n_advance_bytes0 = (ip4_header_bytes (ip40)
3021 + tcp_header_bytes (tcp0));
3022 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
3024 tconn = session_lookup_connection_wt4 (fib_index0,
3029 TRANSPORT_PROTO_TCP,
3035 ip60 = vlib_buffer_get_current (b0);
3036 tcp0 = ip6_next_header (ip60);
3037 n_advance_bytes0 = tcp_header_bytes (tcp0);
3038 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
3040 n_advance_bytes0 += sizeof (ip60[0]);
3041 tconn = session_lookup_connection_wt6 (fib_index0,
3046 TRANSPORT_PROTO_TCP,
3052 if (PREDICT_FALSE (n_advance_bytes0 < 0))
3054 error0 = TCP_ERROR_LENGTH;
3058 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
3059 - (u8 *) vlib_buffer_get_current (b0);
3061 /* Session exists */
3062 if (PREDICT_TRUE (0 != tconn))
3064 tc0 = tcp_get_connection_from_transport (tconn);
3065 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
3067 /* Save connection index */
3068 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
3069 vnet_buffer (b0)->tcp.seq_number =
3070 clib_net_to_host_u32 (tcp0->seq_number);
3071 vnet_buffer (b0)->tcp.ack_number =
3072 clib_net_to_host_u32 (tcp0->ack_number);
3074 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
3075 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
3077 flags0 = tcp0->flags & filter_flags;
3078 next0 = tm->dispatch_table[tc0->state][flags0].next;
3079 error0 = tm->dispatch_table[tc0->state][flags0].error;
3081 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH
3082 || next0 == TCP_INPUT_NEXT_RESET))
3084 /* Overload tcp flags to store state */
3085 tcp_state_t state0 = tc0->state;
3086 vnet_buffer (b0)->tcp.flags = tc0->state;
3088 if (error0 == TCP_ERROR_DISPATCH)
3089 clib_warning ("disp error state %U flags %U",
3090 format_tcp_state, state0, format_tcp_flags,
3098 next0 = TCP_INPUT_NEXT_DROP;
3099 error0 = TCP_ERROR_FILTERED;
3101 else if ((is_ip4 && tm->punt_unknown4) ||
3102 (!is_ip4 && tm->punt_unknown6))
3104 next0 = TCP_INPUT_NEXT_PUNT;
3105 error0 = TCP_ERROR_PUNT;
3110 next0 = TCP_INPUT_NEXT_RESET;
3111 error0 = TCP_ERROR_NO_LISTENER;
3117 b0->error = error0 ? node->errors[error0] : 0;
3119 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3122 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3123 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3125 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
3126 n_left_to_next, bi0, next0);
3129 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3132 return from_frame->n_vectors;
3136 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3137 vlib_frame_t * from_frame)
3139 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3143 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3144 vlib_frame_t * from_frame)
3146 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3150 VLIB_REGISTER_NODE (tcp4_input_node) =
3152 .function = tcp4_input,
3153 .name = "tcp4-input",
3154 /* Takes a vector of packets. */
3155 .vector_size = sizeof (u32),
3156 .n_errors = TCP_N_ERROR,
3157 .error_strings = tcp_error_strings,
3158 .n_next_nodes = TCP_INPUT_N_NEXT,
3161 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3162 foreach_tcp4_input_next
3165 .format_buffer = format_tcp_header,
3166 .format_trace = format_tcp_rx_trace,
3170 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3173 VLIB_REGISTER_NODE (tcp6_input_node) =
3175 .function = tcp6_input,
3176 .name = "tcp6-input",
3177 /* Takes a vector of packets. */
3178 .vector_size = sizeof (u32),
3179 .n_errors = TCP_N_ERROR,
3180 .error_strings = tcp_error_strings,
3181 .n_next_nodes = TCP_INPUT_N_NEXT,
3184 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3185 foreach_tcp6_input_next
3188 .format_buffer = format_tcp_header,
3189 .format_trace = format_tcp_rx_trace,
3193 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3196 tcp_dispatch_table_init (tcp_main_t * tm)
3199 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3200 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3202 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3203 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3206 #define _(t,f,n,e) \
3208 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3209 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3212 /* SYNs for new connections -> tcp-listen. */
3213 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3214 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3215 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3216 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3218 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3219 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3220 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3221 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3222 /* SYN-ACK for a SYN */
3223 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3225 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3226 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3227 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3229 /* ACK for for established connection -> tcp-established. */
3230 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3231 /* FIN for for established connection -> tcp-established. */
3232 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3233 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3235 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3236 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3238 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3239 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3241 /* ACK or FIN-ACK to our FIN */
3242 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3243 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3245 /* FIN in reply to our FIN from the other side */
3246 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3247 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3248 /* FIN confirming that the peer (app) has closed */
3249 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3250 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3251 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3253 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3254 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3256 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3257 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3258 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3260 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3261 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3262 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3264 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3265 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3266 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3267 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3268 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3269 TCP_ERROR_CONNECTION_CLOSED);
3274 tcp_input_init (vlib_main_t * vm)
3276 clib_error_t *error = 0;
3277 tcp_main_t *tm = vnet_get_tcp_main ();
3279 if ((error = vlib_call_init_function (vm, tcp_init)))
3282 /* Initialize dispatch table. */
3283 tcp_dispatch_table_init (tm);
3288 VLIB_INIT_FUNCTION (tcp_input_init);
3291 * fd.io coding-style-patch-verification: ON
3294 * eval: (c-set-style "gnu")