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->cc_algo->congestion (tc);
945 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
949 tcp_cc_recovery_exit (tcp_connection_t * tc)
955 tc->snd_nxt = tc->snd_una_max;
956 tcp_recovery_off (tc);
957 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
961 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
963 tc->cc_algo->recovered (tc);
964 tc->snd_rxt_bytes = 0;
966 tc->snd_nxt = tc->snd_una_max;
967 tcp_fastrecovery_off (tc);
968 tcp_fastrecovery_1_smss_off (tc);
969 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
973 tcp_cc_congestion_undo (tcp_connection_t * tc)
975 tc->cwnd = tc->prev_cwnd;
976 tc->ssthresh = tc->prev_ssthresh;
977 tc->snd_nxt = tc->snd_una_max;
979 if (tcp_in_recovery (tc))
980 tcp_cc_recovery_exit (tc);
981 ASSERT (tc->rto_boff == 0);
982 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
983 /* TODO extend for fastrecovery */
987 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
989 return (tcp_in_recovery (tc) && tc->rto_boff == 1
991 && tcp_opts_tstamp (&tc->rcv_opts)
992 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
996 tcp_cc_recover (tcp_connection_t * tc)
998 ASSERT (tcp_in_cong_recovery (tc));
999 if (tcp_cc_is_spurious_retransmit (tc))
1001 tcp_cc_congestion_undo (tc);
1005 if (tcp_in_recovery (tc))
1006 tcp_cc_recovery_exit (tc);
1007 else if (tcp_in_fastrecovery (tc))
1008 tcp_cc_fastrecovery_exit (tc);
1010 ASSERT (tc->rto_boff == 0);
1011 ASSERT (!tcp_in_cong_recovery (tc));
1012 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1017 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1019 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1021 /* Congestion avoidance */
1022 tc->cc_algo->rcv_ack (tc);
1023 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1025 /* If a cumulative ack, make sure dupacks is 0 */
1026 tc->rcv_dupacks = 0;
1028 /* When dupacks hits the threshold we only enter fast retransmit if
1029 * cumulative ack covers more than snd_congestion. Should snd_una
1030 * wrap this test may fail under otherwise valid circumstances.
1031 * Therefore, proactively update snd_congestion when wrap detected. */
1033 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1034 && seq_gt (tc->snd_congestion, tc->snd_una)))
1035 tc->snd_congestion = tc->snd_una - 1;
1039 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1041 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1045 tcp_should_fastrecover (tcp_connection_t * tc)
1047 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1048 || tcp_should_fastrecover_sack (tc));
1052 * One function to rule them all ... and in the darkness bind them
1055 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1060 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1061 * it account for the bytes that left the network.
1065 ASSERT (tc->snd_una != tc->snd_una_max
1066 || tc->sack_sb.last_sacked_bytes);
1070 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1072 ASSERT (tcp_in_fastrecovery (tc));
1073 /* Pure duplicate ack. If some data got acked, it's handled lower */
1074 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1077 else if (tcp_should_fastrecover (tc))
1079 /* Things are already bad */
1080 if (tcp_in_cong_recovery (tc))
1082 tc->rcv_dupacks = 0;
1083 goto partial_ack_test;
1086 /* If of of the two conditions lower hold, reset dupacks because
1087 * we're probably after timeout (RFC6582 heuristics).
1088 * If Cumulative ack does not cover more than congestion threshold,
1090 * 1) The following doesn't hold: The congestion window is greater
1091 * than SMSS bytes and the difference between highest_ack
1092 * and prev_highest_ack is at most 4*SMSS bytes
1093 * 2) Echoed timestamp in the last non-dup ack does not equal the
1096 if (seq_leq (tc->snd_una, tc->snd_congestion)
1097 && ((!(tc->cwnd > tc->snd_mss
1098 && tc->bytes_acked <= 4 * tc->snd_mss))
1099 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1101 tc->rcv_dupacks = 0;
1105 tcp_cc_init_congestion (tc);
1106 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1108 /* The first segment MUST be retransmitted */
1109 tcp_retransmit_first_unacked (tc);
1111 /* Post retransmit update cwnd to ssthresh and account for the
1112 * three segments that have left the network and should've been
1113 * buffered at the receiver XXX */
1114 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1115 ASSERT (tc->cwnd >= tc->snd_mss);
1117 /* If cwnd allows, send more data */
1118 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1120 scoreboard_init_high_rxt (&tc->sack_sb,
1121 tc->snd_una + tc->snd_mss);
1122 tcp_fast_retransmit_sack (tc);
1126 tcp_fast_retransmit_no_sack (tc);
1131 else if (!tc->bytes_acked
1132 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1134 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1143 if (!tc->bytes_acked)
1148 * Legitimate ACK. 1) See if we can exit recovery
1150 /* XXX limit this only to first partial ack? */
1151 tcp_retransmit_timer_update (tc);
1153 if (seq_geq (tc->snd_una, tc->snd_congestion))
1155 /* If spurious return, we've already updated everything */
1156 if (tcp_cc_recover (tc))
1158 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1162 tc->snd_nxt = tc->snd_una_max;
1164 /* Treat as congestion avoidance ack */
1165 tc->cc_algo->rcv_ack (tc);
1166 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1171 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1173 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1175 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1176 * reset dupacks to 0 */
1177 tc->rcv_dupacks = 0;
1179 tcp_retransmit_first_unacked (tc);
1181 /* Post RTO timeout don't try anything fancy */
1182 if (tcp_in_recovery (tc))
1185 /* Remove retransmitted bytes that have been delivered */
1186 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1187 >= tc->sack_sb.last_bytes_delivered
1188 || (tc->flags & TCP_CONN_FINSNT));
1190 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1192 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1193 * remove sacked bytes delivered */
1194 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1195 - tc->sack_sb.last_bytes_delivered;
1196 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1197 tc->snd_rxt_bytes -= rxt_delivered;
1201 /* Either all retransmitted holes have been acked, or we're
1202 * "in the blind" and retransmitting segment by segment */
1203 tc->snd_rxt_bytes = 0;
1206 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1209 * Since this was a partial ack, try to retransmit some more data
1211 tcp_fast_retransmit (tc);
1215 tcp_cc_init (tcp_connection_t * tc)
1217 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
1218 tc->cc_algo->init (tc);
1222 * Process incoming ACK
1225 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1226 tcp_header_t * th, u32 * next, u32 * error)
1228 u32 prev_snd_wnd, prev_snd_una;
1231 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1233 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1234 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1236 /* If we have outstanding data and this is within the window, accept it,
1237 * probably retransmit has timed out. Otherwise ACK segment and then
1239 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1241 tcp_make_ack (tc, b);
1242 *next = tcp_next_output (tc->c_is_ip4);
1243 *error = TCP_ERROR_ACK_INVALID;
1244 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1245 vnet_buffer (b)->tcp.ack_number);
1249 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1250 vnet_buffer (b)->tcp.ack_number);
1252 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1253 *error = TCP_ERROR_ACK_FUTURE;
1256 /* If old ACK, probably it's an old dupack */
1257 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1259 *error = TCP_ERROR_ACK_OLD;
1260 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1261 vnet_buffer (b)->tcp.ack_number);
1262 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1264 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
1265 tcp_cc_handle_event (tc, 1);
1267 /* Don't drop yet */
1272 * Looks okay, process feedback
1275 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1276 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1278 prev_snd_wnd = tc->snd_wnd;
1279 prev_snd_una = tc->snd_una;
1280 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1281 vnet_buffer (b)->tcp.ack_number,
1282 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1283 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1284 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1285 tcp_validate_txf_size (tc, tc->bytes_acked);
1287 if (tc->bytes_acked)
1288 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1290 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1293 * Check if we have congestion event
1296 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1298 tcp_cc_handle_event (tc, is_dack);
1299 if (!tcp_in_cong_recovery (tc))
1301 *error = TCP_ERROR_ACK_DUP;
1302 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1303 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1307 * Update congestion control (slow start/congestion avoidance)
1309 tcp_cc_update (tc, b);
1310 *error = TCP_ERROR_ACK_OK;
1315 tcp_sack_vector_is_sane (sack_block_t * sacks)
1318 for (i = 1; i < vec_len (sacks); i++)
1320 if (sacks[i - 1].end == sacks[i].start)
1327 * Build SACK list as per RFC2018.
1329 * Makes sure the first block contains the segment that generated the current
1330 * ACK and the following ones are the ones most recently reported in SACK
1333 * @param tc TCP connection for which the SACK list is updated
1334 * @param start Start sequence number of the newest SACK block
1335 * @param end End sequence of the newest SACK block
1338 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1340 sack_block_t *new_list = 0, *block = 0;
1343 /* If the first segment is ooo add it to the list. Last write might've moved
1344 * rcv_nxt over the first segment. */
1345 if (seq_lt (tc->rcv_nxt, start))
1347 vec_add2 (new_list, block, 1);
1348 block->start = start;
1352 /* Find the blocks still worth keeping. */
1353 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1355 /* Discard if rcv_nxt advanced beyond current block */
1356 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1359 /* Merge or drop if segment overlapped by the new segment */
1360 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1361 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1363 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1364 new_list[0].start = tc->snd_sacks[i].start;
1365 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1366 new_list[0].end = tc->snd_sacks[i].end;
1370 /* Save to new SACK list if we have space. */
1371 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1373 vec_add1 (new_list, tc->snd_sacks[i]);
1377 clib_warning ("sack discarded");
1381 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1383 /* Replace old vector with new one */
1384 vec_free (tc->snd_sacks);
1385 tc->snd_sacks = new_list;
1387 /* Segments should not 'touch' */
1388 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1391 /** Enqueue data for delivery to application */
1393 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1396 int written, error = TCP_ERROR_ENQUEUED;
1398 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1400 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1401 1 /* queue event */ , 1);
1403 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1405 /* Update rcv_nxt */
1406 if (PREDICT_TRUE (written == data_len))
1408 tc->rcv_nxt += written;
1410 /* If more data written than expected, account for out-of-order bytes. */
1411 else if (written > data_len)
1413 tc->rcv_nxt += written;
1415 /* Send ACK confirming the update */
1416 tc->flags |= TCP_CONN_SNDACK;
1418 else if (written > 0)
1420 /* We've written something but FIFO is probably full now */
1421 tc->rcv_nxt += written;
1423 /* Depending on how fast the app is, all remaining buffers in burst will
1424 * not be enqueued. Inform peer */
1425 tc->flags |= TCP_CONN_SNDACK;
1427 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1431 tc->flags |= TCP_CONN_SNDACK;
1432 return TCP_ERROR_FIFO_FULL;
1435 /* Update SACK list if need be */
1436 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1438 /* Remove SACK blocks that have been delivered */
1439 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1445 /** Enqueue out-of-order data */
1447 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1450 stream_session_t *s0;
1453 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1456 /* Enqueue out-of-order data with relative offset */
1457 rv = session_enqueue_stream_connection (&tc->connection, b,
1458 vnet_buffer (b)->tcp.seq_number -
1459 tc->rcv_nxt, 0 /* queue event */ ,
1462 /* Nothing written */
1465 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1466 return TCP_ERROR_FIFO_FULL;
1469 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1471 /* Update SACK list if in use */
1472 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1474 ooo_segment_t *newest;
1477 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1479 /* Get the newest segment from the fifo */
1480 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1483 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1484 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1485 start = tc->rcv_nxt + offset;
1486 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1487 tcp_update_sack_list (tc, start, end);
1488 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1492 return TCP_ERROR_ENQUEUED_OOO;
1496 * Check if ACK could be delayed. If ack can be delayed, it should return
1497 * true for a full frame. If we're always acking return 0.
1500 tcp_can_delack (tcp_connection_t * tc)
1502 /* Send ack if ... */
1504 /* just sent a rcv wnd 0 */
1505 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1506 /* constrained to send ack */
1507 || (tc->flags & TCP_CONN_SNDACK) != 0
1508 /* we're almost out of tx wnd */
1509 || tcp_available_snd_space (tc) < 4 * tc->snd_mss)
1516 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1518 u32 discard, first = b->current_length;
1519 vlib_main_t *vm = vlib_get_main ();
1521 /* Handle multi-buffer segments */
1522 if (n_bytes_to_drop > b->current_length)
1524 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1528 discard = clib_min (n_bytes_to_drop, b->current_length);
1529 vlib_buffer_advance (b, discard);
1530 b = vlib_get_buffer (vm, b->next_buffer);
1531 n_bytes_to_drop -= discard;
1533 while (n_bytes_to_drop);
1534 if (n_bytes_to_drop > first)
1535 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1538 vlib_buffer_advance (b, n_bytes_to_drop);
1539 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1544 * Receive buffer for connection and handle acks
1546 * It handles both in order or out-of-order data.
1549 tcp_segment_rcv (tcp_connection_t * tc, vlib_buffer_t * b, u32 * next0)
1551 u32 error, n_bytes_to_drop, n_data_bytes;
1553 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1554 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1555 ASSERT (n_data_bytes);
1557 /* Handle out-of-order data */
1558 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1560 /* Old sequence numbers allowed through because they overlapped
1562 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1564 /* Completely in the past (possible retransmit). Ack
1565 * retransmissions since we may not have any data to send */
1566 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1568 tcp_make_ack (tc, b);
1569 error = TCP_ERROR_SEGMENT_OLD;
1570 *next0 = tcp_next_output (tc->c_is_ip4);
1574 /* Chop off the bytes in the past and see if what is left
1575 * can be enqueued in order */
1576 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1577 n_data_bytes -= n_bytes_to_drop;
1578 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1579 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1581 error = TCP_ERROR_SEGMENT_OLD;
1582 *next0 = tcp_next_drop (tc->c_is_ip4);
1588 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1589 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1590 *next0 = tcp_next_output (tc->c_is_ip4);
1591 tcp_make_ack (tc, b);
1592 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1593 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1599 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1600 * segments can be enqueued after fifo tail offset changes. */
1601 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1602 if (tcp_can_delack (tc))
1604 *next0 = tcp_next_drop (tc->c_is_ip4);
1605 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1606 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1610 *next0 = tcp_next_output (tc->c_is_ip4);
1611 tcp_make_ack (tc, b);
1619 tcp_header_t tcp_header;
1620 tcp_connection_t tcp_connection;
1624 format_tcp_rx_trace (u8 * s, va_list * args)
1626 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1627 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1628 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1629 u32 indent = format_get_indent (s);
1631 s = format (s, "%U\n%U%U",
1632 format_tcp_header, &t->tcp_header, 128,
1633 format_white_space, indent,
1634 format_tcp_connection, &t->tcp_connection, 1);
1640 format_tcp_rx_trace_short (u8 * s, va_list * args)
1642 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1643 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1644 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1646 s = format (s, "%d -> %d (%U)",
1647 clib_net_to_host_u16 (t->tcp_header.src_port),
1648 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1649 t->tcp_connection.state);
1655 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1656 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1660 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1664 th0 = tcp_buffer_hdr (b0);
1666 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1670 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1671 u8 is_ip4, u32 evt, u32 val)
1674 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1676 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1679 #define tcp_maybe_inc_counter(node_id, err, count) \
1681 if (next0 != tcp_next_drop (is_ip4)) \
1682 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1683 tcp6_##node_id##_node.index, is_ip4, err, \
1686 #define tcp_inc_counter(node_id, err, count) \
1687 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1688 tcp6_##node_id##_node.index, is_ip4, \
1690 #define tcp_maybe_inc_err_counter(cnts, err) \
1692 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
1694 #define tcp_inc_err_counter(cnts, err, val) \
1698 #define tcp_store_err_counters(node_id, cnts) \
1701 for (i = 0; i < TCP_N_ERROR; i++) \
1703 tcp_inc_counter(node_id, i, cnts[i]); \
1708 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1709 vlib_frame_t * from_frame, int is_ip4)
1711 u32 my_thread_index = vm->thread_index, errors = 0;
1712 u32 n_left_from, next_index, *from, *to_next;
1713 u16 err_counters[TCP_N_ERROR] = { 0 };
1716 from = vlib_frame_vector_args (from_frame);
1717 n_left_from = from_frame->n_vectors;
1718 next_index = node->cached_next_index;
1720 while (n_left_from > 0)
1724 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1725 while (n_left_from > 0 && n_left_to_next > 0)
1729 tcp_header_t *th0 = 0;
1730 tcp_connection_t *tc0;
1731 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ACK_OK;
1733 if (n_left_from > 1)
1736 pb = vlib_get_buffer (vm, from[1]);
1737 vlib_prefetch_buffer_header (pb, LOAD);
1738 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
1746 n_left_to_next -= 1;
1748 b0 = vlib_get_buffer (vm, bi0);
1749 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1752 if (PREDICT_FALSE (tc0 == 0))
1754 error0 = TCP_ERROR_INVALID_CONNECTION;
1758 th0 = tcp_buffer_hdr (b0);
1759 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1760 * dangling reference. */
1761 is_fin = tcp_is_fin (th0);
1763 /* SYNs, FINs and data consume sequence numbers */
1764 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1765 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1767 /* TODO header prediction fast path */
1769 /* 1-4: check SEQ, RST, SYN */
1770 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0,
1773 tcp_maybe_inc_err_counter (err_counters, error0);
1774 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1775 vnet_buffer (b0)->tcp.seq_number,
1776 vnet_buffer (b0)->tcp.seq_end);
1780 /* 5: check the ACK field */
1781 if (PREDICT_FALSE (tcp_rcv_ack (tc0, b0, th0, &next0, &error0)))
1783 tcp_maybe_inc_err_counter (err_counters, error0);
1787 /* 6: check the URG bit TODO */
1789 /* 7: process the segment text */
1790 if (vnet_buffer (b0)->tcp.data_len)
1792 error0 = tcp_segment_rcv (tc0, b0, &next0);
1793 tcp_maybe_inc_err_counter (err_counters, error0);
1796 /* 8: check the FIN bit */
1797 if (PREDICT_FALSE (is_fin))
1799 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1800 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1801 /* Account for the FIN if nothing else was received */
1802 if (vnet_buffer (b0)->tcp.data_len == 0)
1804 tcp_make_ack (tc0, b0);
1805 next0 = tcp_next_output (tc0->c_is_ip4);
1806 tc0->state = TCP_STATE_CLOSE_WAIT;
1807 stream_session_disconnect_notify (&tc0->connection);
1808 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1809 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1810 tcp_inc_err_counter (err_counters, TCP_ERROR_FIN_RCVD, 1);
1814 b0->error = node->errors[error0];
1815 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1817 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0,
1819 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1822 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1823 n_left_to_next, bi0, next0);
1826 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1829 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
1831 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
1832 tcp_store_err_counters (established, err_counters);
1833 tcp_flush_frame_to_output (vm, my_thread_index, is_ip4);
1834 return from_frame->n_vectors;
1838 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1839 vlib_frame_t * from_frame)
1841 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1845 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1846 vlib_frame_t * from_frame)
1848 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1852 VLIB_REGISTER_NODE (tcp4_established_node) =
1854 .function = tcp4_established,
1855 .name = "tcp4-established",
1856 /* Takes a vector of packets. */
1857 .vector_size = sizeof (u32),
1858 .n_errors = TCP_N_ERROR,
1859 .error_strings = tcp_error_strings,
1860 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1863 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1864 foreach_tcp_state_next
1867 .format_trace = format_tcp_rx_trace_short,
1871 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1874 VLIB_REGISTER_NODE (tcp6_established_node) =
1876 .function = tcp6_established,
1877 .name = "tcp6-established",
1878 /* Takes a vector of packets. */
1879 .vector_size = sizeof (u32),
1880 .n_errors = TCP_N_ERROR,
1881 .error_strings = tcp_error_strings,
1882 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1885 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1886 foreach_tcp_state_next
1889 .format_trace = format_tcp_rx_trace_short,
1894 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1896 vlib_node_registration_t tcp4_syn_sent_node;
1897 vlib_node_registration_t tcp6_syn_sent_node;
1900 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
1902 transport_connection_t *tmp = 0;
1909 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
1912 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
1913 && (tc->state == TCP_STATE_LISTEN
1914 || tc->c_rmt_port == hdr->src_port));
1918 handle = session_lookup_half_open_handle (&tc->connection);
1919 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
1920 tc->c_proto, tc->c_is_ip4);
1924 if (tmp->lcl_port == hdr->dst_port
1925 && tmp->rmt_port == hdr->src_port)
1927 TCP_DBG ("half-open is valid!");
1935 * Lookup transport connection
1937 static tcp_connection_t *
1938 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
1942 transport_connection_t *tconn;
1943 tcp_connection_t *tc;
1948 ip4 = vlib_buffer_get_current (b);
1949 tcp = ip4_next_header (ip4);
1950 tconn = session_lookup_connection_wt4 (fib_index,
1955 TRANSPORT_PROTO_TCP,
1956 thread_index, &is_filtered);
1957 tc = tcp_get_connection_from_transport (tconn);
1958 ASSERT (tcp_lookup_is_valid (tc, tcp));
1963 ip6 = vlib_buffer_get_current (b);
1964 tcp = ip6_next_header (ip6);
1965 tconn = session_lookup_connection_wt6 (fib_index,
1970 TRANSPORT_PROTO_TCP,
1971 thread_index, &is_filtered);
1972 tc = tcp_get_connection_from_transport (tconn);
1973 ASSERT (tcp_lookup_is_valid (tc, tcp));
1979 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1980 vlib_frame_t * from_frame, int is_ip4)
1982 tcp_main_t *tm = vnet_get_tcp_main ();
1983 u32 n_left_from, next_index, *from, *to_next;
1984 u32 my_thread_index = vm->thread_index, errors = 0;
1986 from = vlib_frame_vector_args (from_frame);
1987 n_left_from = from_frame->n_vectors;
1989 next_index = node->cached_next_index;
1991 while (n_left_from > 0)
1995 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1997 while (n_left_from > 0 && n_left_to_next > 0)
1999 u32 bi0, ack0, seq0;
2002 tcp_header_t *tcp0 = 0;
2003 tcp_connection_t *tc0;
2004 tcp_connection_t *new_tc0;
2005 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
2012 n_left_to_next -= 1;
2014 b0 = vlib_get_buffer (vm, bi0);
2016 tcp_half_open_connection_get (vnet_buffer (b0)->
2017 tcp.connection_index);
2018 if (PREDICT_FALSE (tc0 == 0))
2020 error0 = TCP_ERROR_INVALID_CONNECTION;
2024 /* Half-open completed recently but the connection was't removed
2025 * yet by the owning thread */
2026 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2028 /* Make sure the connection actually exists */
2029 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2030 my_thread_index, is_ip4));
2034 ack0 = vnet_buffer (b0)->tcp.ack_number;
2035 seq0 = vnet_buffer (b0)->tcp.seq_number;
2036 tcp0 = tcp_buffer_hdr (b0);
2038 /* Crude check to see if the connection handle does not match
2039 * the packet. Probably connection just switched to established */
2040 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2041 || tcp0->src_port != tc0->c_rmt_port))
2045 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
2048 /* SYNs, FINs and data consume sequence numbers */
2049 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
2050 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
2053 * 1. check the ACK bit
2057 * If the ACK bit is set
2058 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2059 * the RST bit is set, if so drop the segment and return)
2060 * <SEQ=SEG.ACK><CTL=RST>
2061 * and discard the segment. Return.
2062 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2066 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2068 clib_warning ("ack not in rcv wnd");
2069 if (!tcp_rst (tcp0))
2070 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2074 /* Make sure ACK is valid */
2075 if (seq_gt (tc0->snd_una, ack0))
2077 clib_warning ("ack invalid");
2083 * 2. check the RST bit
2088 /* If ACK is acceptable, signal client that peer is not
2089 * willing to accept connection and drop connection*/
2091 tcp_connection_reset (tc0);
2096 * 3. check the security and precedence (skipped)
2100 * 4. check the SYN bit
2103 /* No SYN flag. Drop. */
2104 if (!tcp_syn (tcp0))
2106 clib_warning ("not synack");
2111 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2113 clib_warning ("options parse fail");
2117 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2118 * current thread pool. */
2119 pool_get (tm->connections[my_thread_index], new_tc0);
2120 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2121 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2122 new_tc0->c_thread_index = my_thread_index;
2123 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2124 new_tc0->irs = seq0;
2125 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2126 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2127 TCP_TIMER_HANDLE_INVALID;
2129 /* If this is not the owning thread, wait for syn retransmit to
2130 * expire and cleanup then */
2131 if (tcp_half_open_connection_cleanup (tc0))
2132 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2134 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2136 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2137 new_tc0->tsval_recent_age = tcp_time_now ();
2140 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2141 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2143 /* RFC1323: SYN and SYN-ACK wnd not scaled */
2144 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
2145 new_tc0->snd_wl1 = seq0;
2146 new_tc0->snd_wl2 = ack0;
2148 tcp_connection_init_vars (new_tc0);
2150 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2151 if (PREDICT_TRUE (tcp_ack (tcp0)))
2153 /* Our SYN is ACKed: we have iss < ack = snd_una */
2155 /* TODO Dequeue acknowledged segments if we support Fast Open */
2156 new_tc0->snd_una = ack0;
2157 new_tc0->state = TCP_STATE_ESTABLISHED;
2159 /* Make sure las is initialized for the wnd computation */
2160 new_tc0->rcv_las = new_tc0->rcv_nxt;
2162 /* Notify app that we have connection. If session layer can't
2163 * allocate session send reset */
2164 if (session_stream_connect_notify (&new_tc0->connection, 0))
2166 clib_warning ("connect notify fail");
2167 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2168 tcp_connection_cleanup (new_tc0);
2172 /* Make sure after data segment processing ACK is sent */
2173 new_tc0->flags |= TCP_CONN_SNDACK;
2175 /* Update rtt with the syn-ack sample */
2176 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2177 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2179 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2182 new_tc0->state = TCP_STATE_SYN_RCVD;
2184 /* Notify app that we have connection */
2185 if (session_stream_connect_notify (&new_tc0->connection, 0))
2187 tcp_connection_cleanup (new_tc0);
2188 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2189 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2194 tcp_init_snd_vars (tc0);
2195 tcp_make_synack (new_tc0, b0);
2196 next0 = tcp_next_output (is_ip4);
2201 /* Read data, if any */
2202 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2204 clib_warning ("rcvd data in syn-sent");
2205 error0 = tcp_segment_rcv (new_tc0, b0, &next0);
2206 if (error0 == TCP_ERROR_ACK_OK)
2207 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2208 tcp_maybe_inc_counter (syn_sent, error0, 1);
2212 tcp_make_ack (new_tc0, b0);
2213 next0 = tcp_next_output (new_tc0->c_is_ip4);
2218 b0->error = error0 ? node->errors[error0] : 0;
2220 ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2222 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2223 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2224 clib_memcpy (&t0->tcp_connection, tc0,
2225 sizeof (t0->tcp_connection));
2228 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2229 n_left_to_next, bi0, next0);
2232 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2235 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2237 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2238 return from_frame->n_vectors;
2242 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2243 vlib_frame_t * from_frame)
2245 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2249 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2250 vlib_frame_t * from_frame)
2252 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2256 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2258 .function = tcp4_syn_sent,
2259 .name = "tcp4-syn-sent",
2260 /* Takes a vector of packets. */
2261 .vector_size = sizeof (u32),
2262 .n_errors = TCP_N_ERROR,
2263 .error_strings = tcp_error_strings,
2264 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2267 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2268 foreach_tcp_state_next
2271 .format_trace = format_tcp_rx_trace_short,
2275 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2278 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2280 .function = tcp6_syn_sent_rcv,
2281 .name = "tcp6-syn-sent",
2282 /* Takes a vector of packets. */
2283 .vector_size = sizeof (u32),
2284 .n_errors = TCP_N_ERROR,
2285 .error_strings = tcp_error_strings,
2286 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2289 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2290 foreach_tcp_state_next
2293 .format_trace = format_tcp_rx_trace_short,
2297 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2299 vlib_node_registration_t tcp4_rcv_process_node;
2300 vlib_node_registration_t tcp6_rcv_process_node;
2303 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2304 * as per RFC793 p. 64
2307 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2308 vlib_frame_t * from_frame, int is_ip4)
2310 u32 n_left_from, next_index, *from, *to_next, n_fins = 0;
2311 u32 my_thread_index = vm->thread_index, errors = 0;
2313 from = vlib_frame_vector_args (from_frame);
2314 n_left_from = from_frame->n_vectors;
2315 next_index = node->cached_next_index;
2317 while (n_left_from > 0)
2321 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2323 while (n_left_from > 0 && n_left_to_next > 0)
2327 tcp_header_t *tcp0 = 0;
2328 tcp_connection_t *tc0;
2329 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_NONE;
2337 n_left_to_next -= 1;
2339 b0 = vlib_get_buffer (vm, bi0);
2340 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2342 if (PREDICT_FALSE (tc0 == 0))
2344 error0 = TCP_ERROR_INVALID_CONNECTION;
2348 tcp0 = tcp_buffer_hdr (b0);
2349 is_fin0 = tcp_is_fin (tcp0);
2351 /* SYNs, FINs and data consume sequence numbers */
2352 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2353 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2357 tcp_connection_t *tmp;
2358 tmp = tcp_lookup_connection (tc0->c_fib_index, b0,
2359 my_thread_index, is_ip4);
2360 if (tmp->state != tc0->state)
2362 clib_warning ("state changed");
2368 * Special treatment for CLOSED
2370 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2372 error0 = TCP_ERROR_CONNECTION_CLOSED;
2377 * For all other states (except LISTEN)
2380 /* 1-4: check SEQ, RST, SYN */
2381 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2384 tcp_maybe_inc_counter (rcv_process, error0, 1);
2388 /* 5: check the ACK field */
2391 case TCP_STATE_SYN_RCVD:
2393 * If the segment acknowledgment is not acceptable, form a
2395 * <SEQ=SEG.ACK><CTL=RST>
2398 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2400 TCP_DBG ("connection not accepted");
2401 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2402 error0 = TCP_ERROR_ACK_INVALID;
2406 /* Update rtt and rto */
2407 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2409 /* Switch state to ESTABLISHED */
2410 tc0->state = TCP_STATE_ESTABLISHED;
2411 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2413 /* Initialize session variables */
2414 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2415 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2416 << tc0->rcv_opts.wscale;
2417 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2418 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2420 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2421 tcp_retransmit_timer_reset (tc0);
2422 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2423 stream_session_accept_notify (&tc0->connection);
2424 error0 = TCP_ERROR_ACK_OK;
2426 case TCP_STATE_ESTABLISHED:
2427 /* We can get packets in established state here because they
2428 * were enqueued before state change */
2429 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2431 tcp_maybe_inc_counter (rcv_process, error0, 1);
2436 case TCP_STATE_FIN_WAIT_1:
2437 /* In addition to the processing for the ESTABLISHED state, if
2438 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2439 * continue processing in that state. */
2440 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2442 tcp_maybe_inc_counter (rcv_process, error0, 1);
2446 /* Still have to send the FIN */
2447 if (tc0->flags & TCP_CONN_FINPNDG)
2449 /* TX fifo finally drained */
2450 if (!stream_session_tx_fifo_max_dequeue (&tc0->connection))
2453 /* If FIN is ACKed */
2454 else if (tc0->snd_una == tc0->snd_una_max)
2456 tc0->state = TCP_STATE_FIN_WAIT_2;
2457 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2459 /* Stop all retransmit timers because we have nothing more
2460 * to send. Enable waitclose though because we're willing to
2461 * wait for peer's FIN but not indefinitely. */
2462 tcp_connection_timers_reset (tc0);
2463 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2466 case TCP_STATE_FIN_WAIT_2:
2467 /* In addition to the processing for the ESTABLISHED state, if
2468 * the retransmission queue is empty, the user's CLOSE can be
2469 * acknowledged ("ok") but do not delete the TCB. */
2470 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2472 tcp_maybe_inc_counter (rcv_process, error0, 1);
2476 case TCP_STATE_CLOSE_WAIT:
2477 /* Do the same processing as for the ESTABLISHED state. */
2478 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2480 tcp_maybe_inc_counter (rcv_process, error0, 1);
2484 case TCP_STATE_CLOSING:
2485 /* In addition to the processing for the ESTABLISHED state, if
2486 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2487 * otherwise ignore the segment. */
2488 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2490 tcp_maybe_inc_counter (rcv_process, error0, 1);
2494 tc0->state = TCP_STATE_TIME_WAIT;
2495 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2496 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2500 case TCP_STATE_LAST_ACK:
2501 /* The only thing that [should] arrive in this state is an
2502 * acknowledgment of our FIN. If our FIN is now acknowledged,
2503 * delete the TCB, enter the CLOSED state, and return. */
2505 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2507 error0 = TCP_ERROR_ACK_INVALID;
2510 error0 = TCP_ERROR_ACK_OK;
2511 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2512 /* Apparently our ACK for the peer's FIN was lost */
2513 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2519 tc0->state = TCP_STATE_CLOSED;
2520 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2521 tcp_connection_timers_reset (tc0);
2523 /* Don't delete the connection/session yet. Instead, wait a
2524 * reasonable amount of time until the pipes are cleared. In
2525 * particular, this makes sure that we won't have dead sessions
2526 * when processing events on the tx path */
2527 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2532 case TCP_STATE_TIME_WAIT:
2533 /* The only thing that can arrive in this state is a
2534 * retransmission of the remote FIN. Acknowledge it, and restart
2535 * the 2 MSL timeout. */
2537 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2539 tcp_maybe_inc_counter (rcv_process, error0, 1);
2543 tcp_make_ack (tc0, b0);
2544 next0 = tcp_next_output (is_ip4);
2545 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2553 /* 6: check the URG bit TODO */
2555 /* 7: process the segment text */
2558 case TCP_STATE_ESTABLISHED:
2559 case TCP_STATE_FIN_WAIT_1:
2560 case TCP_STATE_FIN_WAIT_2:
2561 if (vnet_buffer (b0)->tcp.data_len)
2563 error0 = tcp_segment_rcv (tc0, b0, &next0);
2564 tcp_maybe_inc_counter (rcv_process, error0, 1);
2569 case TCP_STATE_CLOSE_WAIT:
2570 case TCP_STATE_CLOSING:
2571 case TCP_STATE_LAST_ACK:
2572 case TCP_STATE_TIME_WAIT:
2573 /* This should not occur, since a FIN has been received from the
2574 * remote side. Ignore the segment text. */
2578 /* 8: check the FIN bit */
2584 case TCP_STATE_ESTABLISHED:
2585 case TCP_STATE_SYN_RCVD:
2586 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2587 tcp_connection_timers_reset (tc0);
2588 tcp_make_fin (tc0, b0);
2590 next0 = tcp_next_output (tc0->c_is_ip4);
2591 stream_session_disconnect_notify (&tc0->connection);
2592 tc0->state = TCP_STATE_CLOSE_WAIT;
2593 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2595 case TCP_STATE_CLOSE_WAIT:
2596 case TCP_STATE_CLOSING:
2597 case TCP_STATE_LAST_ACK:
2600 case TCP_STATE_FIN_WAIT_1:
2601 tc0->state = TCP_STATE_CLOSING;
2602 tcp_make_ack (tc0, b0);
2603 next0 = tcp_next_output (is_ip4);
2604 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2605 /* Wait for ACK but not forever */
2606 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2608 case TCP_STATE_FIN_WAIT_2:
2609 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2610 tc0->state = TCP_STATE_TIME_WAIT;
2611 tcp_connection_timers_reset (tc0);
2612 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2613 tcp_make_ack (tc0, b0);
2614 next0 = tcp_next_output (is_ip4);
2615 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2617 case TCP_STATE_TIME_WAIT:
2618 /* Remain in the TIME-WAIT state. Restart the time-wait
2621 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2624 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2628 b0->error = error0 ? node->errors[error0] : 0;
2630 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2632 tcp_rx_trace_t *t0 =
2633 vlib_add_trace (vm, node, b0, sizeof (*t0));
2634 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2637 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2638 n_left_to_next, bi0, next0);
2641 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2644 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2646 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2647 tcp_inc_counter (rcv_process, TCP_ERROR_FIN_RCVD, n_fins);
2648 return from_frame->n_vectors;
2652 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2653 vlib_frame_t * from_frame)
2655 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2659 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2660 vlib_frame_t * from_frame)
2662 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2666 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2668 .function = tcp4_rcv_process,
2669 .name = "tcp4-rcv-process",
2670 /* Takes a vector of packets. */
2671 .vector_size = sizeof (u32),
2672 .n_errors = TCP_N_ERROR,
2673 .error_strings = tcp_error_strings,
2674 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2677 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2678 foreach_tcp_state_next
2681 .format_trace = format_tcp_rx_trace_short,
2685 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2688 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2690 .function = tcp6_rcv_process,
2691 .name = "tcp6-rcv-process",
2692 /* Takes a vector of packets. */
2693 .vector_size = sizeof (u32),
2694 .n_errors = TCP_N_ERROR,
2695 .error_strings = tcp_error_strings,
2696 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2699 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2700 foreach_tcp_state_next
2703 .format_trace = format_tcp_rx_trace_short,
2707 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2709 vlib_node_registration_t tcp4_listen_node;
2710 vlib_node_registration_t tcp6_listen_node;
2713 * LISTEN state processing as per RFC 793 p. 65
2716 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2717 vlib_frame_t * from_frame, int is_ip4)
2719 u32 n_left_from, next_index, *from, *to_next, n_syns = 0;
2720 u32 my_thread_index = vm->thread_index;
2722 from = vlib_frame_vector_args (from_frame);
2723 n_left_from = from_frame->n_vectors;
2725 next_index = node->cached_next_index;
2727 while (n_left_from > 0)
2731 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2733 while (n_left_from > 0 && n_left_to_next > 0)
2738 tcp_header_t *th0 = 0;
2739 tcp_connection_t *lc0;
2742 tcp_connection_t *child0;
2743 u32 error0 = TCP_ERROR_NONE, next0 = tcp_next_drop (is_ip4);
2750 n_left_to_next -= 1;
2752 b0 = vlib_get_buffer (vm, bi0);
2753 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2757 ip40 = vlib_buffer_get_current (b0);
2758 th0 = ip4_next_header (ip40);
2762 ip60 = vlib_buffer_get_current (b0);
2763 th0 = ip6_next_header (ip60);
2766 /* Create child session. For syn-flood protection use filter */
2768 /* 1. first check for an RST: handled in dispatch */
2769 /* if (tcp_rst (th0))
2772 /* 2. second check for an ACK: handled in dispatch */
2773 /* if (tcp_ack (th0))
2775 tcp_send_reset (b0, is_ip4);
2779 /* 3. check for a SYN (did that already) */
2781 /* Make sure connection wasn't just created */
2783 tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
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")