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 _ (DROP, "error-drop") \
31 _ (TCP4_OUTPUT, "tcp4-output") \
32 _ (TCP6_OUTPUT, "tcp6-output")
34 typedef enum _tcp_established_next
36 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
37 foreach_tcp_state_next
39 TCP_ESTABLISHED_N_NEXT,
40 } tcp_established_next_t;
42 typedef enum _tcp_rcv_process_next
44 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
45 foreach_tcp_state_next
47 TCP_RCV_PROCESS_N_NEXT,
48 } tcp_rcv_process_next_t;
50 typedef enum _tcp_syn_sent_next
52 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
53 foreach_tcp_state_next
56 } tcp_syn_sent_next_t;
58 typedef enum _tcp_listen_next
60 #define _(s,n) TCP_LISTEN_NEXT_##s,
61 foreach_tcp_state_next
66 /* Generic, state independent indices */
67 typedef enum _tcp_state_next
69 #define _(s,n) TCP_NEXT_##s,
70 foreach_tcp_state_next
75 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
76 : TCP_NEXT_TCP6_OUTPUT)
78 vlib_node_registration_t tcp4_established_node;
79 vlib_node_registration_t tcp6_established_node;
82 * Validate segment sequence number. As per RFC793:
84 * Segment Receive Test
86 * ------- ------- -------------------------------------------
87 * 0 0 SEG.SEQ = RCV.NXT
88 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
90 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
91 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
93 * This ultimately consists in checking if segment falls within the window.
94 * The one important difference compared to RFC793 is that we use rcv_las,
95 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
96 * peer's reference when computing our receive window.
99 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
100 * however, is too strict when we have retransmits. Instead we just check that
101 * the seq is not beyond the right edge and that the end of the segment is not
102 * less than the left edge.
104 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
105 * use rcv_nxt in the right edge window test instead of rcv_las.
109 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
111 return (seq_geq (end_seq, tc->rcv_las)
112 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
116 * Parse TCP header options.
118 * @param th TCP header
119 * @param to TCP options data structure to be populated
120 * @return -1 if parsing failed
123 tcp_options_parse (tcp_header_t * th, tcp_options_t * to)
126 u8 opt_len, opts_len, kind;
130 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
131 data = (const u8 *) (th + 1);
133 /* Zero out all flags but those set in SYN */
134 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE);
136 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
140 /* Get options length */
141 if (kind == TCP_OPTION_EOL)
143 else if (kind == TCP_OPTION_NOOP)
155 /* weird option length */
156 if (opt_len < 2 || opt_len > opts_len)
164 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
166 to->flags |= TCP_OPTS_FLAG_MSS;
167 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
170 case TCP_OPTION_WINDOW_SCALE:
171 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
173 to->flags |= TCP_OPTS_FLAG_WSCALE;
174 to->wscale = data[2];
175 if (to->wscale > TCP_MAX_WND_SCALE)
177 clib_warning ("Illegal window scaling value: %d",
179 to->wscale = TCP_MAX_WND_SCALE;
183 case TCP_OPTION_TIMESTAMP:
184 if (opt_len == TCP_OPTION_LEN_TIMESTAMP)
186 to->flags |= TCP_OPTS_FLAG_TSTAMP;
187 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
188 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
191 case TCP_OPTION_SACK_PERMITTED:
192 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
193 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
195 case TCP_OPTION_SACK_BLOCK:
196 /* If SACK permitted was not advertised or a SYN, break */
197 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
200 /* If too short or not correctly formatted, break */
201 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
204 to->flags |= TCP_OPTS_FLAG_SACK;
205 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
206 vec_reset_length (to->sacks);
207 for (j = 0; j < to->n_sack_blocks; j++)
209 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
210 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
211 vec_add1 (to->sacks, b);
215 /* Nothing to see here */
223 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
224 * timestamp to echo and it's less than tsval_recent, drop segment
225 * but still send an ACK in order to retain TCP's mechanism for detecting
226 * and recovering from half-open connections
228 * Or at least that's what the theory says. It seems that this might not work
229 * very well with packet reordering and fast retransmit. XXX
232 tcp_segment_check_paws (tcp_connection_t * tc)
234 return tcp_opts_tstamp (&tc->rcv_opts) && tc->tsval_recent
235 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
239 * Update tsval recent
242 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
245 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
246 * of an incoming segment:
247 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
248 * then the TSval from the segment is copied to TS.Recent;
249 * otherwise, the TSval is ignored.
251 if (tcp_opts_tstamp (&tc->rcv_opts) && tc->tsval_recent
252 && seq_leq (seq, tc->rcv_las) && seq_leq (tc->rcv_las, seq_end))
254 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
255 tc->tsval_recent = tc->rcv_opts.tsval;
256 tc->tsval_recent_age = tcp_time_now ();
261 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
263 * It first verifies if segment has a wrapped sequence number (PAWS) and then
264 * does the processing associated to the first four steps (ignoring security
265 * and precedence): sequence number, rst bit and syn bit checks.
267 * @return 0 if segments passes validation.
270 tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0,
271 vlib_buffer_t * b0, tcp_header_t * th0, u32 * next0)
273 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
276 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts)))
278 clib_warning ("options parse error");
282 if (tcp_segment_check_paws (tc0))
286 clib_warning ("paws failed\n%U", format_tcp_connection, tc0, 2);
287 clib_warning ("seq %u seq_end %u ack %u",
288 vnet_buffer (b0)->tcp.seq_number - tc0->irs,
289 vnet_buffer (b0)->tcp.seq_end - tc0->irs,
290 vnet_buffer (b0)->tcp.ack_number - tc0->iss);
292 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
293 vnet_buffer (b0)->tcp.seq_end);
295 /* If it just so happens that a segment updates tsval_recent for a
296 * segment over 24 days old, invalidate tsval_recent. */
297 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
300 /* Age isn't reset until we get a valid tsval (bsd inspired) */
301 tc0->tsval_recent = 0;
302 clib_warning ("paws failed - really old segment. REALLY?");
306 /* Drop after ack if not rst */
309 tcp_make_ack (tc0, b0);
310 *next0 = tcp_next_output (tc0->c_is_ip4);
311 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
317 /* 1st: check sequence number */
318 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
319 vnet_buffer (b0)->tcp.seq_end))
321 /* If our window is 0 and the packet is in sequence, let it pass
322 * through for ack processing. It should be dropped later.*/
323 if (tc0->rcv_wnd == 0
324 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
326 /* TODO Should segment be tagged? */
330 /* If not RST, send dup ack */
333 tcp_make_ack (tc0, b0);
334 *next0 = tcp_next_output (tc0->c_is_ip4);
335 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
341 /* 2nd: check the RST bit */
344 tcp_connection_reset (tc0);
348 /* 3rd: check security and precedence (skip) */
350 /* 4th: check the SYN bit */
353 /* TODO implement RFC 5961 */
354 if (tc0->state == TCP_STATE_SYN_RCVD)
356 tcp_make_synack (tc0, b0);
357 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
361 tcp_make_ack (tc0, b0);
362 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
364 *next0 = tcp_next_output (tc0->c_is_ip4);
368 /* If segment in window, save timestamp */
369 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
370 vnet_buffer (b0)->tcp.seq_end);
375 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
377 /* SND.UNA =< SEG.ACK =< SND.NXT */
378 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
379 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
383 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
385 * Note that although the original article, srtt and rttvar are scaled
386 * to minimize round-off errors, here we don't. Instead, we rely on
387 * better precision time measurements.
389 * TODO support us rtt resolution
392 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
398 err = mrtt - tc->srtt;
400 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
401 * The increase should be bound */
402 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
403 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
404 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
408 /* First measurement. */
410 tc->rttvar = mrtt >> 1;
415 tcp_update_rto (tcp_connection_t * tc)
417 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
418 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
421 /** Update RTT estimate and RTO timer
423 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
424 * timing. Middle boxes are known to fiddle with TCP options so we
425 * should give higher priority to ACK timing.
427 * return 1 if valid rtt 0 otherwise
430 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
435 /* Determine if only rtx bytes are acked. */
436 rtx_acked = tcp_in_cong_recovery (tc) || !tc->bytes_acked;
438 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
439 * RTT because they're ambiguous. */
440 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq) && !rtx_acked)
442 mrtt = tcp_time_now () - tc->rtt_ts;
444 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
445 * snd_una, i.e., the left side of the send window:
446 * seq_lt (tc->snd_una, ack). */
447 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr
450 mrtt = tcp_time_now () - tc->rcv_opts.tsecr;
453 /* Allow measuring of a new RTT */
456 /* If ACK moves left side of the wnd make sure boff is 0, even if mrtt is
461 /* Ignore dubious measurements */
462 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
465 tcp_estimate_rtt (tc, mrtt);
472 * Dequeue bytes that have been acked and while at it update RTT estimates.
475 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
477 /* Dequeue the newly ACKed add SACKed bytes */
478 stream_session_dequeue_drop (&tc->connection,
479 tc->bytes_acked + tc->sack_sb.snd_una_adv);
481 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
483 /* Update rtt and rto */
484 tcp_update_rtt (tc, ack);
486 /* If everything has been acked, stop retransmit timer
487 * otherwise update. */
488 tcp_retransmit_timer_update (tc);
492 * Check if duplicate ack as per RFC5681 Sec. 2
495 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
498 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
499 && seq_gt (tc->snd_una_max, tc->snd_una)
500 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
501 && (prev_snd_wnd == tc->snd_wnd));
505 * Checks if ack is a congestion control event.
508 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
509 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
511 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
512 * defined to be 'duplicate' */
513 *is_dack = tc->sack_sb.last_sacked_bytes
514 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
516 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
520 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
522 sack_scoreboard_hole_t *next, *prev;
524 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
526 next = pool_elt_at_index (sb->holes, hole->next);
527 next->prev = hole->prev;
531 sb->tail = hole->prev;
534 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
536 prev = pool_elt_at_index (sb->holes, hole->prev);
537 prev->next = hole->next;
541 sb->head = hole->next;
544 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
545 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
547 /* Poison the entry */
549 memset (hole, 0xfe, sizeof (*hole));
551 pool_put (sb->holes, hole);
554 sack_scoreboard_hole_t *
555 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
558 sack_scoreboard_hole_t *hole, *next, *prev;
561 pool_get (sb->holes, hole);
562 memset (hole, 0, sizeof (*hole));
566 hole_index = scoreboard_hole_index (sb, hole);
568 prev = scoreboard_get_hole (sb, prev_index);
571 hole->prev = prev_index;
572 hole->next = prev->next;
574 if ((next = scoreboard_next_hole (sb, hole)))
575 next->prev = hole_index;
577 sb->tail = hole_index;
579 prev->next = hole_index;
583 sb->head = hole_index;
584 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
585 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
592 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
594 sack_scoreboard_hole_t *hole, *prev;
595 u32 bytes = 0, blks = 0;
598 sb->sacked_bytes = 0;
599 hole = scoreboard_last_hole (sb);
603 if (seq_gt (sb->high_sacked, hole->end))
605 bytes = sb->high_sacked - hole->end;
609 while ((prev = scoreboard_prev_hole (sb, hole))
610 && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
611 && blks < TCP_DUPACK_THRESHOLD))
613 bytes += hole->start - prev->end;
620 sb->lost_bytes += scoreboard_hole_bytes (hole);
623 hole = scoreboard_prev_hole (sb, hole);
625 bytes += prev->start - hole->end;
627 sb->sacked_bytes = bytes;
631 * Figure out the next hole to retransmit
633 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
635 sack_scoreboard_hole_t *
636 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
637 sack_scoreboard_hole_t * start,
639 u8 * can_rescue, u8 * snd_limited)
641 sack_scoreboard_hole_t *hole = 0;
643 hole = start ? start : scoreboard_first_hole (sb);
644 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
645 hole = scoreboard_next_hole (sb, hole);
647 /* Nothing, return */
650 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
654 /* Rule (1): if higher than rxt, less than high_sacked and lost */
655 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
657 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
661 /* Rule (2): output takes care of transmitting new data */
662 if (!have_sent_1_smss)
665 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
667 /* Rule (3): if hole not lost */
668 else if (seq_lt (hole->start, sb->high_sacked))
671 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
673 /* Rule (4): if hole beyond high_sacked */
676 ASSERT (seq_geq (hole->start, sb->high_sacked));
679 /* HighRxt MUST NOT be updated */
684 if (hole && seq_lt (sb->high_rxt, hole->start))
685 sb->high_rxt = hole->start;
691 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
693 sack_scoreboard_hole_t *hole;
694 hole = scoreboard_first_hole (sb);
697 seq = seq_gt (seq, hole->start) ? seq : hole->start;
698 sb->cur_rxt_hole = sb->head;
704 * Test that scoreboard is sane after recovery
706 * Returns 1 if scoreboard is empty or if first hole beyond
710 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
712 sack_scoreboard_hole_t *hole;
713 hole = scoreboard_first_hole (&tc->sack_sb);
714 return (!hole || seq_geq (hole->start, tc->snd_una));
718 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
720 sack_scoreboard_t *sb = &tc->sack_sb;
721 sack_block_t *blk, tmp;
722 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
723 u32 blk_index = 0, old_sacked_bytes, hole_index;
726 sb->last_sacked_bytes = 0;
728 old_sacked_bytes = sb->sacked_bytes;
729 sb->last_bytes_delivered = 0;
731 if (!tcp_opts_sack (&tc->rcv_opts)
732 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
735 /* Remove invalid blocks */
736 blk = tc->rcv_opts.sacks;
737 while (blk < vec_end (tc->rcv_opts.sacks))
739 if (seq_lt (blk->start, blk->end)
740 && seq_gt (blk->start, tc->snd_una)
741 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
746 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
749 /* Add block for cumulative ack */
750 if (seq_gt (ack, tc->snd_una))
752 tmp.start = tc->snd_una;
754 vec_add1 (tc->rcv_opts.sacks, tmp);
757 if (vec_len (tc->rcv_opts.sacks) == 0)
760 tcp_scoreboard_trace_add (tc, ack);
762 /* Make sure blocks are ordered */
763 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
764 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
765 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
767 tmp = tc->rcv_opts.sacks[i];
768 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
769 tc->rcv_opts.sacks[j] = tmp;
772 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
774 /* If no holes, insert the first that covers all outstanding bytes */
775 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
776 tc->snd_una, tc->snd_una_max);
777 sb->tail = scoreboard_hole_index (sb, last_hole);
778 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
779 sb->high_sacked = tmp.end;
783 /* If we have holes but snd_una_max is beyond the last hole, update
785 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
786 last_hole = scoreboard_last_hole (sb);
787 if (seq_gt (tc->snd_una_max, last_hole->end))
789 if (seq_geq (last_hole->start, sb->high_sacked))
791 last_hole->end = tc->snd_una_max;
793 /* New hole after high sacked block */
794 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
796 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
800 /* Keep track of max byte sacked for when the last hole
802 if (seq_gt (tmp.end, sb->high_sacked))
803 sb->high_sacked = tmp.end;
806 /* Walk the holes with the SACK blocks */
807 hole = pool_elt_at_index (sb->holes, sb->head);
808 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
810 blk = &tc->rcv_opts.sacks[blk_index];
811 if (seq_leq (blk->start, hole->start))
813 /* Block covers hole. Remove hole */
814 if (seq_geq (blk->end, hole->end))
816 next_hole = scoreboard_next_hole (sb, hole);
818 /* Byte accounting: snd_una needs to be advanced */
823 if (seq_lt (ack, next_hole->start))
824 sb->snd_una_adv = next_hole->start - ack;
825 sb->last_bytes_delivered +=
826 next_hole->start - hole->end;
830 ASSERT (seq_geq (sb->high_sacked, ack));
831 sb->snd_una_adv = sb->high_sacked - ack;
832 sb->last_bytes_delivered += sb->high_sacked - hole->end;
836 scoreboard_remove_hole (sb, hole);
839 /* Partial 'head' overlap */
842 if (seq_gt (blk->end, hole->start))
844 hole->start = blk->end;
851 /* Hole must be split */
852 if (seq_lt (blk->end, hole->end))
854 hole_index = scoreboard_hole_index (sb, hole);
855 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
858 /* Pool might've moved */
859 hole = scoreboard_get_hole (sb, hole_index);
860 hole->end = blk->start;
862 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
864 else if (seq_lt (blk->start, hole->end))
866 hole->end = blk->start;
868 hole = scoreboard_next_hole (sb, hole);
872 scoreboard_update_bytes (tc, sb);
873 sb->last_sacked_bytes = sb->sacked_bytes
874 - (old_sacked_bytes - sb->last_bytes_delivered);
875 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes);
876 ASSERT (sb->sacked_bytes == 0
877 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
878 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
879 - seq_max (tc->snd_una, ack));
880 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
881 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
885 * Try to update snd_wnd based on feedback received from peer.
887 * If successful, and new window is 'effectively' 0, activate persist
891 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
893 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
894 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
895 if (seq_lt (tc->snd_wl1, seq)
896 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
898 tc->snd_wnd = snd_wnd;
901 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
903 if (tc->snd_wnd < tc->snd_mss)
905 /* Set persist timer if not set and we just got 0 wnd */
906 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
907 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
908 tcp_persist_timer_set (tc);
912 tcp_persist_timer_reset (tc);
913 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
923 tcp_cc_init_congestion (tcp_connection_t * tc)
925 tcp_fastrecovery_on (tc);
926 tc->snd_congestion = tc->snd_una_max;
927 tc->cc_algo->congestion (tc);
928 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
932 tcp_cc_recovery_exit (tcp_connection_t * tc)
938 tcp_recovery_off (tc);
942 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
944 tc->cc_algo->recovered (tc);
945 tc->snd_rxt_bytes = 0;
947 tcp_fastrecovery_off (tc);
948 tcp_fastrecovery_1_smss_off (tc);
952 tcp_cc_congestion_undo (tcp_connection_t * tc)
954 tc->cwnd = tc->prev_cwnd;
955 tc->ssthresh = tc->prev_ssthresh;
956 tc->snd_nxt = tc->snd_una_max;
958 if (tcp_in_recovery (tc))
959 tcp_cc_recovery_exit (tc);
960 ASSERT (tc->rto_boff == 0);
961 /* TODO extend for fastrecovery */
965 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
967 return (tcp_in_recovery (tc)
969 && tcp_opts_tstamp (&tc->rcv_opts)
970 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
974 tcp_cc_recover (tcp_connection_t * tc)
976 ASSERT (tcp_in_cong_recovery (tc));
977 if (tcp_cc_is_spurious_retransmit (tc))
979 tcp_cc_congestion_undo (tc);
983 if (tcp_in_recovery (tc))
984 tcp_cc_recovery_exit (tc);
985 else if (tcp_in_fastrecovery (tc))
986 tcp_cc_fastrecovery_exit (tc);
988 ASSERT (tc->rto_boff == 0);
989 ASSERT (!tcp_in_cong_recovery (tc));
990 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
991 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
996 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
998 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1000 /* Congestion avoidance */
1001 tc->cc_algo->rcv_ack (tc);
1002 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1004 /* If a cumulative ack, make sure dupacks is 0 */
1005 tc->rcv_dupacks = 0;
1007 /* When dupacks hits the threshold we only enter fast retransmit if
1008 * cumulative ack covers more than snd_congestion. Should snd_una
1009 * wrap this test may fail under otherwise valid circumstances.
1010 * Therefore, proactively update snd_congestion when wrap detected. */
1012 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1013 && seq_gt (tc->snd_congestion, tc->snd_una)))
1014 tc->snd_congestion = tc->snd_una - 1;
1018 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1020 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1024 tcp_should_fastrecover (tcp_connection_t * tc)
1026 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1027 || tcp_should_fastrecover_sack (tc));
1031 * One function to rule them all ... and in the darkness bind them
1034 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1039 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1040 * it account for the bytes that left the network.
1044 ASSERT (tc->snd_una != tc->snd_una_max
1045 || tc->sack_sb.last_sacked_bytes);
1049 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1051 ASSERT (tcp_in_fastrecovery (tc));
1052 /* Pure duplicate ack. If some data got acked, it's handled lower */
1053 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1056 else if (tcp_should_fastrecover (tc))
1058 /* Things are already bad */
1059 if (tcp_in_cong_recovery (tc))
1061 tc->rcv_dupacks = 0;
1062 goto partial_ack_test;
1065 /* If of of the two conditions lower hold, reset dupacks because
1066 * we're probably after timeout (RFC6582 heuristics).
1067 * If Cumulative ack does not cover more than congestion threshold,
1069 * 1) The following doesn't hold: The congestion window is greater
1070 * than SMSS bytes and the difference between highest_ack
1071 * and prev_highest_ack is at most 4*SMSS bytes
1072 * 2) Echoed timestamp in the last non-dup ack does not equal the
1075 if (seq_leq (tc->snd_una, tc->snd_congestion)
1076 && ((!(tc->cwnd > tc->snd_mss
1077 && tc->bytes_acked <= 4 * tc->snd_mss))
1078 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1080 tc->rcv_dupacks = 0;
1084 tcp_cc_init_congestion (tc);
1085 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1087 /* The first segment MUST be retransmitted */
1088 tcp_retransmit_first_unacked (tc);
1090 /* Post retransmit update cwnd to ssthresh and account for the
1091 * three segments that have left the network and should've been
1092 * buffered at the receiver XXX */
1093 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1094 ASSERT (tc->cwnd >= tc->snd_mss);
1096 /* If cwnd allows, send more data */
1097 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1099 scoreboard_init_high_rxt (&tc->sack_sb,
1100 tc->snd_una + tc->snd_mss);
1101 tcp_fast_retransmit_sack (tc);
1105 tcp_fast_retransmit_no_sack (tc);
1110 else if (!tc->bytes_acked
1111 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1113 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1122 if (!tc->bytes_acked)
1127 * Legitimate ACK. 1) See if we can exit recovery
1129 /* XXX limit this only to first partial ack? */
1130 tcp_retransmit_timer_update (tc);
1132 if (seq_geq (tc->snd_una, tc->snd_congestion))
1134 /* If spurious return, we've already updated everything */
1135 if (tcp_cc_recover (tc))
1137 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1141 tc->snd_nxt = tc->snd_una_max;
1143 /* Treat as congestion avoidance ack */
1144 tc->cc_algo->rcv_ack (tc);
1145 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1150 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1152 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1154 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1155 * reset dupacks to 0 */
1156 tc->rcv_dupacks = 0;
1158 tcp_retransmit_first_unacked (tc);
1160 /* Post RTO timeout don't try anything fancy */
1161 if (tcp_in_recovery (tc))
1164 /* Remove retransmitted bytes that have been delivered */
1165 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1166 >= tc->sack_sb.last_bytes_delivered
1167 || (tc->flags & TCP_CONN_FINSNT));
1169 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1171 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1172 * remove sacked bytes delivered */
1173 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1174 - tc->sack_sb.last_bytes_delivered;
1175 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1176 tc->snd_rxt_bytes -= rxt_delivered;
1180 /* Either all retransmitted holes have been acked, or we're
1181 * "in the blind" and retransmitting segment by segment */
1182 tc->snd_rxt_bytes = 0;
1185 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1188 * Since this was a partial ack, try to retransmit some more data
1190 tcp_fast_retransmit (tc);
1194 tcp_cc_init (tcp_connection_t * tc)
1196 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
1197 tc->cc_algo->init (tc);
1201 * Process incoming ACK
1204 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1205 tcp_header_t * th, u32 * next, u32 * error)
1207 u32 prev_snd_wnd, prev_snd_una;
1210 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1212 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1213 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1215 /* If we have outstanding data and this is within the window, accept it,
1216 * probably retransmit has timed out. Otherwise ACK segment and then
1218 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1220 tcp_make_ack (tc, b);
1221 *next = tcp_next_output (tc->c_is_ip4);
1222 *error = TCP_ERROR_ACK_INVALID;
1223 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1224 vnet_buffer (b)->tcp.ack_number);
1228 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1229 vnet_buffer (b)->tcp.ack_number);
1231 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1232 *error = TCP_ERROR_ACK_FUTURE;
1235 /* If old ACK, probably it's an old dupack */
1236 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1238 *error = TCP_ERROR_ACK_OLD;
1239 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1240 vnet_buffer (b)->tcp.ack_number);
1241 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1243 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
1244 tcp_cc_handle_event (tc, 1);
1246 /* Don't drop yet */
1251 * Looks okay, process feedback
1254 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1255 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1257 prev_snd_wnd = tc->snd_wnd;
1258 prev_snd_una = tc->snd_una;
1259 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1260 vnet_buffer (b)->tcp.ack_number,
1261 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1262 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1263 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1264 tcp_validate_txf_size (tc, tc->bytes_acked);
1266 if (tc->bytes_acked)
1267 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1269 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1272 * Check if we have congestion event
1275 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1277 tcp_cc_handle_event (tc, is_dack);
1278 if (!tcp_in_cong_recovery (tc))
1280 *error = TCP_ERROR_ACK_DUP;
1281 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1282 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1286 * Update congestion control (slow start/congestion avoidance)
1288 tcp_cc_update (tc, b);
1294 tcp_sack_vector_is_sane (sack_block_t * sacks)
1297 for (i = 1; i < vec_len (sacks); i++)
1299 if (sacks[i - 1].end == sacks[i].start)
1306 * Build SACK list as per RFC2018.
1308 * Makes sure the first block contains the segment that generated the current
1309 * ACK and the following ones are the ones most recently reported in SACK
1312 * @param tc TCP connection for which the SACK list is updated
1313 * @param start Start sequence number of the newest SACK block
1314 * @param end End sequence of the newest SACK block
1317 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1319 sack_block_t *new_list = 0, *block = 0;
1322 /* If the first segment is ooo add it to the list. Last write might've moved
1323 * rcv_nxt over the first segment. */
1324 if (seq_lt (tc->rcv_nxt, start))
1326 vec_add2 (new_list, block, 1);
1327 block->start = start;
1331 /* Find the blocks still worth keeping. */
1332 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1334 /* Discard if rcv_nxt advanced beyond current block */
1335 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1338 /* Merge or drop if segment overlapped by the new segment */
1339 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1340 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1342 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1343 new_list[0].start = tc->snd_sacks[i].start;
1344 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1345 new_list[0].end = tc->snd_sacks[i].end;
1349 /* Save to new SACK list if we have space. */
1350 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1352 vec_add1 (new_list, tc->snd_sacks[i]);
1356 clib_warning ("sack discarded");
1360 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1362 /* Replace old vector with new one */
1363 vec_free (tc->snd_sacks);
1364 tc->snd_sacks = new_list;
1366 /* Segments should not 'touch' */
1367 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1370 /** Enqueue data for delivery to application */
1372 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1375 int written, error = TCP_ERROR_ENQUEUED;
1377 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1379 /* Pure ACK. Update rcv_nxt and be done. */
1380 if (PREDICT_FALSE (data_len == 0))
1382 return TCP_ERROR_PURE_ACK;
1385 written = stream_session_enqueue_data (&tc->connection, b, 0,
1386 1 /* queue event */ , 1);
1388 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1390 /* Update rcv_nxt */
1391 if (PREDICT_TRUE (written == data_len))
1393 tc->rcv_nxt += written;
1395 /* If more data written than expected, account for out-of-order bytes. */
1396 else if (written > data_len)
1398 tc->rcv_nxt += written;
1400 /* Send ACK confirming the update */
1401 tc->flags |= TCP_CONN_SNDACK;
1403 else if (written > 0)
1405 /* We've written something but FIFO is probably full now */
1406 tc->rcv_nxt += written;
1408 /* Depending on how fast the app is, all remaining buffers in burst will
1409 * not be enqueued. Inform peer */
1410 tc->flags |= TCP_CONN_SNDACK;
1412 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1416 tc->flags |= TCP_CONN_SNDACK;
1417 return TCP_ERROR_FIFO_FULL;
1420 /* Update SACK list if need be */
1421 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1423 /* Remove SACK blocks that have been delivered */
1424 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1430 /** Enqueue out-of-order data */
1432 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1435 stream_session_t *s0;
1438 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1440 /* Pure ACK. Do nothing */
1441 if (PREDICT_FALSE (data_len == 0))
1443 return TCP_ERROR_PURE_ACK;
1446 /* Enqueue out-of-order data with relative offset */
1447 rv = stream_session_enqueue_data (&tc->connection, b,
1448 vnet_buffer (b)->tcp.seq_number -
1449 tc->rcv_nxt, 0 /* queue event */ , 0);
1451 /* Nothing written */
1454 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1455 return TCP_ERROR_FIFO_FULL;
1458 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1460 /* Update SACK list if in use */
1461 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1463 ooo_segment_t *newest;
1466 s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
1468 /* Get the newest segment from the fifo */
1469 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1472 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1473 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1474 start = tc->rcv_nxt + offset;
1475 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1476 tcp_update_sack_list (tc, start, end);
1477 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1481 return TCP_ERROR_ENQUEUED;
1485 * Check if ACK could be delayed. If ack can be delayed, it should return
1486 * true for a full frame. If we're always acking return 0.
1489 tcp_can_delack (tcp_connection_t * tc)
1491 /* Send ack if ... */
1493 /* just sent a rcv wnd 0 */
1494 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1495 /* constrained to send ack */
1496 || (tc->flags & TCP_CONN_SNDACK) != 0
1497 /* we're almost out of tx wnd */
1498 || tcp_available_snd_space (tc) < 4 * tc->snd_mss)
1505 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1507 u32 discard, first = b->current_length;
1508 vlib_main_t *vm = vlib_get_main ();
1510 /* Handle multi-buffer segments */
1511 if (n_bytes_to_drop > b->current_length)
1513 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1517 discard = clib_min (n_bytes_to_drop, b->current_length);
1518 vlib_buffer_advance (b, discard);
1519 b = vlib_get_buffer (vm, b->next_buffer);
1520 n_bytes_to_drop -= discard;
1522 while (n_bytes_to_drop);
1523 if (n_bytes_to_drop > first)
1524 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1527 vlib_buffer_advance (b, n_bytes_to_drop);
1528 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1533 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1536 u32 error = 0, n_bytes_to_drop, n_data_bytes;
1538 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1539 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1540 ASSERT (n_data_bytes);
1542 /* Handle out-of-order data */
1543 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1545 /* Old sequence numbers allowed through because they overlapped
1547 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1549 error = TCP_ERROR_SEGMENT_OLD;
1550 *next0 = TCP_NEXT_DROP;
1552 /* Completely in the past (possible retransmit) */
1553 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1555 /* Ack retransmissions since we may not have any data to send */
1556 tcp_make_ack (tc, b);
1557 *next0 = tcp_next_output (tc->c_is_ip4);
1561 /* Chop off the bytes in the past */
1562 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1563 n_data_bytes -= n_bytes_to_drop;
1564 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1565 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1571 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1573 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1574 * cwnd on remote peer when congested 2) acks leaving should have the
1575 * latest rcv_wnd since the burst may eaten up all of it, so only the
1576 * old ones could be filtered.
1579 /* RFC2581: Send DUPACK for fast retransmit */
1580 tcp_make_ack (tc, b);
1581 *next0 = tcp_next_output (tc->c_is_ip4);
1583 /* Mark as DUPACK. We may filter these in output if
1584 * the burst fills the holes. */
1586 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1588 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1594 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1595 * segments can be enqueued after fifo tail offset changes. */
1596 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1598 /* Check if ACK can be delayed */
1599 if (tcp_can_delack (tc))
1601 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1602 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1606 *next0 = tcp_next_output (tc->c_is_ip4);
1607 tcp_make_ack (tc, b);
1615 tcp_header_t tcp_header;
1616 tcp_connection_t tcp_connection;
1620 format_tcp_rx_trace (u8 * s, va_list * args)
1622 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1623 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1624 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1625 uword indent = format_get_indent (s);
1627 s = format (s, "%U\n%U%U",
1628 format_tcp_header, &t->tcp_header, 128,
1629 format_white_space, indent,
1630 format_tcp_connection, &t->tcp_connection, 1);
1636 format_tcp_rx_trace_short (u8 * s, va_list * args)
1638 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1639 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1640 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1642 s = format (s, "%d -> %d (%U)",
1643 clib_net_to_host_u16 (t->tcp_header.src_port),
1644 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1645 t->tcp_connection.state);
1651 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1652 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1656 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1660 th0 = tcp_buffer_hdr (b0);
1662 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1666 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1668 if (PREDICT_TRUE (!val))
1672 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1674 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1678 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1679 vlib_frame_t * from_frame, int is_ip4)
1681 u32 n_left_from, next_index, *from, *to_next;
1682 u32 my_thread_index = vm->thread_index, errors = 0;
1683 tcp_main_t *tm = vnet_get_tcp_main ();
1686 from = vlib_frame_vector_args (from_frame);
1687 n_left_from = from_frame->n_vectors;
1689 next_index = node->cached_next_index;
1691 while (n_left_from > 0)
1695 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1696 while (n_left_from > 0 && n_left_to_next > 0)
1700 tcp_header_t *th0 = 0;
1701 tcp_connection_t *tc0;
1702 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1709 n_left_to_next -= 1;
1711 b0 = vlib_get_buffer (vm, bi0);
1712 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1715 if (PREDICT_FALSE (tc0 == 0))
1717 error0 = TCP_ERROR_INVALID_CONNECTION;
1721 th0 = tcp_buffer_hdr (b0);
1722 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1723 * dangling reference. */
1724 is_fin = tcp_is_fin (th0);
1726 /* SYNs, FINs and data consume sequence numbers */
1727 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1728 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1730 /* TODO header prediction fast path */
1732 /* 1-4: check SEQ, RST, SYN */
1733 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1735 error0 = TCP_ERROR_SEGMENT_INVALID;
1736 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1737 vnet_buffer (b0)->tcp.seq_number,
1738 vnet_buffer (b0)->tcp.seq_end);
1742 /* 5: check the ACK field */
1743 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1746 /* 6: check the URG bit TODO */
1748 /* 7: process the segment text */
1749 if (vnet_buffer (b0)->tcp.data_len)
1750 error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
1752 /* 8: check the FIN bit */
1753 if (PREDICT_FALSE (is_fin))
1755 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1756 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1757 /* Account for the FIN if nothing else was received */
1758 if (vnet_buffer (b0)->tcp.data_len == 0)
1760 tcp_make_ack (tc0, b0);
1761 next0 = tcp_next_output (tc0->c_is_ip4);
1762 tc0->state = TCP_STATE_CLOSE_WAIT;
1763 stream_session_disconnect_notify (&tc0->connection);
1764 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1765 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1769 b0->error = node->errors[error0];
1770 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1772 tcp_rx_trace_t *t0 =
1773 vlib_add_trace (vm, node, b0, sizeof (*t0));
1774 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1777 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1778 n_left_to_next, bi0, next0);
1781 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1784 errors = session_manager_flush_enqueue_events (my_thread_index);
1785 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1786 tcp_flush_frame_to_output (vm, my_thread_index, is_ip4);
1788 return from_frame->n_vectors;
1792 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1793 vlib_frame_t * from_frame)
1795 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1799 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1800 vlib_frame_t * from_frame)
1802 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1806 VLIB_REGISTER_NODE (tcp4_established_node) =
1808 .function = tcp4_established,
1809 .name = "tcp4-established",
1810 /* Takes a vector of packets. */
1811 .vector_size = sizeof (u32),
1812 .n_errors = TCP_N_ERROR,
1813 .error_strings = tcp_error_strings,
1814 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1817 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1818 foreach_tcp_state_next
1821 .format_trace = format_tcp_rx_trace_short,
1825 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1828 VLIB_REGISTER_NODE (tcp6_established_node) =
1830 .function = tcp6_established,
1831 .name = "tcp6-established",
1832 /* Takes a vector of packets. */
1833 .vector_size = sizeof (u32),
1834 .n_errors = TCP_N_ERROR,
1835 .error_strings = tcp_error_strings,
1836 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1839 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1840 foreach_tcp_state_next
1843 .format_trace = format_tcp_rx_trace_short,
1848 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1850 vlib_node_registration_t tcp4_syn_sent_node;
1851 vlib_node_registration_t tcp6_syn_sent_node;
1854 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
1856 transport_connection_t *tmp;
1860 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
1861 && (tc->state == TCP_STATE_LISTEN
1862 || tc->c_rmt_port == hdr->src_port));
1867 stream_session_half_open_lookup (&tc->c_lcl_ip, &tc->c_rmt_ip,
1868 tc->c_lcl_port, tc->c_rmt_port,
1869 tc->c_transport_proto)))
1871 if (tmp->lcl_port == hdr->dst_port
1872 && tmp->rmt_port == hdr->src_port)
1874 clib_warning ("half-open is valid!");
1882 * Lookup transport connection
1884 static tcp_connection_t *
1885 tcp_lookup_connection (vlib_buffer_t * b, u8 thread_index, u8 is_ip4)
1888 transport_connection_t *tconn;
1889 tcp_connection_t *tc;
1893 ip4 = vlib_buffer_get_current (b);
1894 tcp = ip4_next_header (ip4);
1895 tconn = stream_session_lookup_transport_wt4 (&ip4->dst_address,
1899 SESSION_TYPE_IP4_TCP,
1901 tc = tcp_get_connection_from_transport (tconn);
1902 ASSERT (tcp_lookup_is_valid (tc, tcp));
1907 ip6 = vlib_buffer_get_current (b);
1908 tcp = ip6_next_header (ip6);
1909 tconn = stream_session_lookup_transport_wt6 (&ip6->dst_address,
1913 SESSION_TYPE_IP6_TCP,
1915 tc = tcp_get_connection_from_transport (tconn);
1916 ASSERT (tcp_lookup_is_valid (tc, tcp));
1922 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1923 vlib_frame_t * from_frame, int is_ip4)
1925 tcp_main_t *tm = vnet_get_tcp_main ();
1926 u32 n_left_from, next_index, *from, *to_next;
1927 u32 my_thread_index = vm->thread_index, errors = 0;
1929 from = vlib_frame_vector_args (from_frame);
1930 n_left_from = from_frame->n_vectors;
1932 next_index = node->cached_next_index;
1934 while (n_left_from > 0)
1938 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1940 while (n_left_from > 0 && n_left_to_next > 0)
1942 u32 bi0, ack0, seq0;
1945 tcp_header_t *tcp0 = 0;
1946 tcp_connection_t *tc0;
1947 tcp_connection_t *new_tc0;
1948 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1955 n_left_to_next -= 1;
1957 b0 = vlib_get_buffer (vm, bi0);
1959 tcp_half_open_connection_get (vnet_buffer (b0)->
1960 tcp.connection_index);
1961 if (PREDICT_FALSE (tc0 == 0))
1963 error0 = TCP_ERROR_INVALID_CONNECTION;
1967 /* Half-open completed recently but the connection was't removed
1968 * yet by the owning thread */
1969 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
1971 /* Make sure the connection actually exists */
1972 ASSERT (tcp_lookup_connection (b0, my_thread_index, is_ip4));
1976 ack0 = vnet_buffer (b0)->tcp.ack_number;
1977 seq0 = vnet_buffer (b0)->tcp.seq_number;
1978 tcp0 = tcp_buffer_hdr (b0);
1980 /* Crude check to see if the connection handle does not match
1981 * the packet. Probably connection just switched to established */
1982 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
1983 || tcp0->src_port != tc0->c_rmt_port))
1987 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1990 /* SYNs, FINs and data consume sequence numbers */
1991 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1992 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
1995 * 1. check the ACK bit
1999 * If the ACK bit is set
2000 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2001 * the RST bit is set, if so drop the segment and return)
2002 * <SEQ=SEG.ACK><CTL=RST>
2003 * and discard the segment. Return.
2004 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2008 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2010 clib_warning ("ack not in rcv wnd");
2011 if (!tcp_rst (tcp0))
2012 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2016 /* Make sure ACK is valid */
2017 if (seq_gt (tc0->snd_una, ack0))
2019 clib_warning ("ack invalid");
2025 * 2. check the RST bit
2030 /* If ACK is acceptable, signal client that peer is not
2031 * willing to accept connection and drop connection*/
2033 tcp_connection_reset (tc0);
2038 * 3. check the security and precedence (skipped)
2042 * 4. check the SYN bit
2045 /* No SYN flag. Drop. */
2046 if (!tcp_syn (tcp0))
2048 clib_warning ("not synack");
2053 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2055 clib_warning ("options parse fail");
2059 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2060 * current thread pool. */
2061 pool_get (tm->connections[my_thread_index], new_tc0);
2062 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2063 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2064 new_tc0->c_thread_index = my_thread_index;
2065 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2066 new_tc0->irs = seq0;
2067 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2068 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2069 TCP_TIMER_HANDLE_INVALID;
2071 /* If this is not the owning thread, wait for syn retransmit to
2072 * expire and cleanup then */
2073 if (tcp_half_open_connection_cleanup (tc0))
2074 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2076 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2078 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2079 new_tc0->tsval_recent_age = tcp_time_now ();
2082 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2083 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2085 /* RFC1323: SYN and SYN-ACK wnd not scaled */
2086 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
2087 new_tc0->snd_wl1 = seq0;
2088 new_tc0->snd_wl2 = ack0;
2090 tcp_connection_init_vars (new_tc0);
2092 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2093 if (PREDICT_TRUE (tcp_ack (tcp0)))
2095 /* Our SYN is ACKed: we have iss < ack = snd_una */
2097 /* TODO Dequeue acknowledged segments if we support Fast Open */
2098 new_tc0->snd_una = ack0;
2099 new_tc0->state = TCP_STATE_ESTABLISHED;
2101 /* Make sure las is initialized for the wnd computation */
2102 new_tc0->rcv_las = new_tc0->rcv_nxt;
2104 /* Notify app that we have connection. If session layer can't
2105 * allocate session send reset */
2106 if (stream_session_connect_notify (&new_tc0->connection, 0))
2108 clib_warning ("connect notify fail");
2109 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2110 tcp_connection_cleanup (new_tc0);
2114 /* Make sure after data segment processing ACK is sent */
2115 new_tc0->flags |= TCP_CONN_SNDACK;
2117 /* Update rtt with the syn-ack sample */
2118 new_tc0->bytes_acked = 1;
2119 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2120 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2122 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2125 new_tc0->state = TCP_STATE_SYN_RCVD;
2127 /* Notify app that we have connection */
2128 if (stream_session_connect_notify (&new_tc0->connection, 0))
2130 tcp_connection_cleanup (new_tc0);
2131 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2132 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2137 tcp_init_snd_vars (tc0);
2138 tcp_make_synack (new_tc0, b0);
2139 next0 = tcp_next_output (is_ip4);
2144 /* Read data, if any */
2145 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2148 error0 = tcp_segment_rcv (tm, new_tc0, b0, &next0);
2149 if (error0 == TCP_ERROR_PURE_ACK)
2150 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2154 tcp_make_ack (new_tc0, b0);
2155 next0 = tcp_next_output (new_tc0->c_is_ip4);
2160 b0->error = error0 ? node->errors[error0] : 0;
2161 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2163 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2164 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2165 clib_memcpy (&t0->tcp_connection, tc0,
2166 sizeof (t0->tcp_connection));
2169 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2170 n_left_to_next, bi0, next0);
2173 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2176 errors = session_manager_flush_enqueue_events (my_thread_index);
2180 vlib_node_increment_counter (vm, tcp4_established_node.index,
2181 TCP_ERROR_EVENT_FIFO_FULL, errors);
2183 vlib_node_increment_counter (vm, tcp6_established_node.index,
2184 TCP_ERROR_EVENT_FIFO_FULL, errors);
2187 return from_frame->n_vectors;
2191 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2192 vlib_frame_t * from_frame)
2194 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2198 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2199 vlib_frame_t * from_frame)
2201 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2205 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2207 .function = tcp4_syn_sent,
2208 .name = "tcp4-syn-sent",
2209 /* Takes a vector of packets. */
2210 .vector_size = sizeof (u32),
2211 .n_errors = TCP_N_ERROR,
2212 .error_strings = tcp_error_strings,
2213 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2216 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2217 foreach_tcp_state_next
2220 .format_trace = format_tcp_rx_trace_short,
2224 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2227 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2229 .function = tcp6_syn_sent_rcv,
2230 .name = "tcp6-syn-sent",
2231 /* Takes a vector of packets. */
2232 .vector_size = sizeof (u32),
2233 .n_errors = TCP_N_ERROR,
2234 .error_strings = tcp_error_strings,
2235 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2238 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2239 foreach_tcp_state_next
2242 .format_trace = format_tcp_rx_trace_short,
2246 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2249 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2250 * as per RFC793 p. 64
2253 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2254 vlib_frame_t * from_frame, int is_ip4)
2256 tcp_main_t *tm = vnet_get_tcp_main ();
2257 u32 n_left_from, next_index, *from, *to_next;
2258 u32 my_thread_index = vm->thread_index, errors = 0;
2260 from = vlib_frame_vector_args (from_frame);
2261 n_left_from = from_frame->n_vectors;
2263 next_index = node->cached_next_index;
2265 while (n_left_from > 0)
2269 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2271 while (n_left_from > 0 && n_left_to_next > 0)
2275 tcp_header_t *tcp0 = 0;
2276 tcp_connection_t *tc0;
2277 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
2285 n_left_to_next -= 1;
2287 b0 = vlib_get_buffer (vm, bi0);
2288 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2290 if (PREDICT_FALSE (tc0 == 0))
2292 error0 = TCP_ERROR_INVALID_CONNECTION;
2296 tcp0 = tcp_buffer_hdr (b0);
2297 is_fin0 = tcp_is_fin (tcp0);
2299 /* SYNs, FINs and data consume sequence numbers */
2300 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2301 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2305 tcp_connection_t *tmp;
2306 tmp = tcp_lookup_connection (b0, my_thread_index, is_ip4);
2307 if (tmp->state != tc0->state)
2309 clib_warning ("state changed");
2316 * Special treatment for CLOSED
2320 case TCP_STATE_CLOSED:
2326 * For all other states (except LISTEN)
2329 /* 1-4: check SEQ, RST, SYN */
2330 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2333 error0 = TCP_ERROR_SEGMENT_INVALID;
2337 /* 5: check the ACK field */
2340 case TCP_STATE_SYN_RCVD:
2342 * If the segment acknowledgment is not acceptable, form a
2344 * <SEQ=SEG.ACK><CTL=RST>
2347 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2349 clib_warning ("connection not accepted");
2350 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2354 /* Update rtt and rto */
2355 tc0->bytes_acked = 1;
2356 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2358 /* Switch state to ESTABLISHED */
2359 tc0->state = TCP_STATE_ESTABLISHED;
2361 /* Initialize session variables */
2362 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2363 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2364 << tc0->rcv_opts.wscale;
2365 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2366 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2367 stream_session_accept_notify (&tc0->connection);
2369 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2370 tcp_retransmit_timer_reset (tc0);
2371 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2372 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2374 case TCP_STATE_ESTABLISHED:
2375 /* We can get packets in established state here because they
2376 * were enqueued before state change */
2377 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2381 case TCP_STATE_FIN_WAIT_1:
2382 /* In addition to the processing for the ESTABLISHED state, if
2383 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2384 * continue processing in that state. */
2385 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2388 /* Still have to send the FIN */
2389 if (tc0->flags & TCP_CONN_FINPNDG)
2391 /* TX fifo finally drained */
2392 if (!stream_session_tx_fifo_max_dequeue (&tc0->connection))
2395 /* If FIN is ACKed */
2396 else if (tc0->snd_una == tc0->snd_una_max)
2398 tc0->state = TCP_STATE_FIN_WAIT_2;
2399 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2401 /* Stop all retransmit timers because we have nothing more
2402 * to send. Enable waitclose though because we're willing to
2403 * wait for peer's FIN but not indefinitely. */
2404 tcp_connection_timers_reset (tc0);
2405 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2408 case TCP_STATE_FIN_WAIT_2:
2409 /* In addition to the processing for the ESTABLISHED state, if
2410 * the retransmission queue is empty, the user's CLOSE can be
2411 * acknowledged ("ok") but do not delete the TCB. */
2412 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2415 case TCP_STATE_CLOSE_WAIT:
2416 /* Do the same processing as for the ESTABLISHED state. */
2417 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2420 case TCP_STATE_CLOSING:
2421 /* In addition to the processing for the ESTABLISHED state, if
2422 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2423 * otherwise ignore the segment. */
2424 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2427 tc0->state = TCP_STATE_TIME_WAIT;
2428 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2429 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2433 case TCP_STATE_LAST_ACK:
2434 /* The only thing that [should] arrive in this state is an
2435 * acknowledgment of our FIN. If our FIN is now acknowledged,
2436 * delete the TCB, enter the CLOSED state, and return. */
2438 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2441 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2442 /* Apparently our FIN was lost */
2449 tc0->state = TCP_STATE_CLOSED;
2450 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2452 /* Don't delete the connection/session yet. Instead, wait a
2453 * reasonable amount of time until the pipes are cleared. In
2454 * particular, this makes sure that we won't have dead sessions
2455 * when processing events on the tx path */
2456 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2457 tcp_retransmit_timer_reset (tc0);
2462 case TCP_STATE_TIME_WAIT:
2463 /* The only thing that can arrive in this state is a
2464 * retransmission of the remote FIN. Acknowledge it, and restart
2465 * the 2 MSL timeout. */
2467 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2470 tcp_make_ack (tc0, b0);
2471 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2480 /* 6: check the URG bit TODO */
2482 /* 7: process the segment text */
2485 case TCP_STATE_ESTABLISHED:
2486 case TCP_STATE_FIN_WAIT_1:
2487 case TCP_STATE_FIN_WAIT_2:
2488 if (vnet_buffer (b0)->tcp.data_len)
2489 error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
2493 case TCP_STATE_CLOSE_WAIT:
2494 case TCP_STATE_CLOSING:
2495 case TCP_STATE_LAST_ACK:
2496 case TCP_STATE_TIME_WAIT:
2497 /* This should not occur, since a FIN has been received from the
2498 * remote side. Ignore the segment text. */
2502 /* 8: check the FIN bit */
2508 case TCP_STATE_ESTABLISHED:
2509 case TCP_STATE_SYN_RCVD:
2510 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2511 tcp_connection_timers_reset (tc0);
2512 tcp_make_fin (tc0, b0);
2514 next0 = tcp_next_output (tc0->c_is_ip4);
2515 stream_session_disconnect_notify (&tc0->connection);
2516 tc0->state = TCP_STATE_CLOSE_WAIT;
2517 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2519 case TCP_STATE_CLOSE_WAIT:
2520 case TCP_STATE_CLOSING:
2521 case TCP_STATE_LAST_ACK:
2524 case TCP_STATE_FIN_WAIT_1:
2525 tc0->state = TCP_STATE_CLOSING;
2526 tcp_make_ack (tc0, b0);
2527 next0 = tcp_next_output (is_ip4);
2528 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2529 /* Wait for ACK but not forever */
2530 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2532 case TCP_STATE_FIN_WAIT_2:
2533 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2534 tc0->state = TCP_STATE_TIME_WAIT;
2535 tcp_connection_timers_reset (tc0);
2536 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2537 tcp_make_ack (tc0, b0);
2538 next0 = tcp_next_output (is_ip4);
2539 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2541 case TCP_STATE_TIME_WAIT:
2542 /* Remain in the TIME-WAIT state. Restart the time-wait
2545 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2548 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2551 b0->error = error0 ? node->errors[error0] : 0;
2553 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2555 tcp_rx_trace_t *t0 =
2556 vlib_add_trace (vm, node, b0, sizeof (*t0));
2557 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2560 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2561 n_left_to_next, bi0, next0);
2564 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2567 errors = session_manager_flush_enqueue_events (my_thread_index);
2571 vlib_node_increment_counter (vm, tcp4_established_node.index,
2572 TCP_ERROR_EVENT_FIFO_FULL, errors);
2574 vlib_node_increment_counter (vm, tcp6_established_node.index,
2575 TCP_ERROR_EVENT_FIFO_FULL, errors);
2578 return from_frame->n_vectors;
2582 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2583 vlib_frame_t * from_frame)
2585 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2589 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2590 vlib_frame_t * from_frame)
2592 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2596 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2598 .function = tcp4_rcv_process,
2599 .name = "tcp4-rcv-process",
2600 /* Takes a vector of packets. */
2601 .vector_size = sizeof (u32),
2602 .n_errors = TCP_N_ERROR,
2603 .error_strings = tcp_error_strings,
2604 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2607 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2608 foreach_tcp_state_next
2611 .format_trace = format_tcp_rx_trace_short,
2615 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2618 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2620 .function = tcp6_rcv_process,
2621 .name = "tcp6-rcv-process",
2622 /* Takes a vector of packets. */
2623 .vector_size = sizeof (u32),
2624 .n_errors = TCP_N_ERROR,
2625 .error_strings = tcp_error_strings,
2626 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2629 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2630 foreach_tcp_state_next
2633 .format_trace = format_tcp_rx_trace_short,
2637 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2639 vlib_node_registration_t tcp4_listen_node;
2640 vlib_node_registration_t tcp6_listen_node;
2643 * LISTEN state processing as per RFC 793 p. 65
2646 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2647 vlib_frame_t * from_frame, int is_ip4)
2649 u32 n_left_from, next_index, *from, *to_next;
2650 u32 my_thread_index = vm->thread_index;
2651 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
2653 from = vlib_frame_vector_args (from_frame);
2654 n_left_from = from_frame->n_vectors;
2656 next_index = node->cached_next_index;
2658 while (n_left_from > 0)
2662 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2664 while (n_left_from > 0 && n_left_to_next > 0)
2669 tcp_header_t *th0 = 0;
2670 tcp_connection_t *lc0;
2673 tcp_connection_t *child0;
2674 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2681 n_left_to_next -= 1;
2683 b0 = vlib_get_buffer (vm, bi0);
2684 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2688 ip40 = vlib_buffer_get_current (b0);
2689 th0 = ip4_next_header (ip40);
2693 ip60 = vlib_buffer_get_current (b0);
2694 th0 = ip6_next_header (ip60);
2697 /* Create child session. For syn-flood protection use filter */
2699 /* 1. first check for an RST: handled in dispatch */
2700 /* if (tcp_rst (th0))
2703 /* 2. second check for an ACK: handled in dispatch */
2704 /* if (tcp_ack (th0))
2706 tcp_send_reset (b0, is_ip4);
2710 /* 3. check for a SYN (did that already) */
2712 /* Make sure connection wasn't just created */
2713 child0 = tcp_lookup_connection (b0, my_thread_index, is_ip4);
2714 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
2716 error0 = TCP_ERROR_CREATE_EXISTS;
2720 /* Create child session and send SYN-ACK */
2721 child0 = tcp_connection_new (my_thread_index);
2722 child0->c_lcl_port = lc0->c_lcl_port;
2723 child0->c_rmt_port = th0->src_port;
2724 child0->c_is_ip4 = is_ip4;
2725 child0->state = TCP_STATE_SYN_RCVD;
2729 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2730 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2734 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2735 sizeof (ip6_address_t));
2736 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2737 sizeof (ip6_address_t));
2740 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2743 clib_warning ("session accept fail");
2744 tcp_connection_cleanup (child0);
2745 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2749 if (tcp_options_parse (th0, &child0->rcv_opts))
2751 clib_warning ("options parse fail");
2755 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2756 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2757 child0->rcv_las = child0->rcv_nxt;
2759 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2760 * segments are used to initialize PAWS. */
2761 if (tcp_opts_tstamp (&child0->rcv_opts))
2763 child0->tsval_recent = child0->rcv_opts.tsval;
2764 child0->tsval_recent_age = tcp_time_now ();
2767 if (tcp_opts_wscale (&child0->rcv_opts))
2768 child0->snd_wscale = child0->rcv_opts.wscale;
2770 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2771 << child0->snd_wscale;
2772 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2773 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2775 tcp_connection_init_vars (child0);
2776 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
2778 /* Reuse buffer to make syn-ack and send */
2779 tcp_make_synack (child0, b0);
2780 next0 = tcp_next_output (is_ip4);
2781 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
2784 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2786 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2787 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2788 clib_memcpy (&t0->tcp_connection, lc0,
2789 sizeof (t0->tcp_connection));
2792 b0->error = node->errors[error0];
2794 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2795 n_left_to_next, bi0, next0);
2798 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2800 return from_frame->n_vectors;
2804 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2805 vlib_frame_t * from_frame)
2807 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2811 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2812 vlib_frame_t * from_frame)
2814 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2818 VLIB_REGISTER_NODE (tcp4_listen_node) =
2820 .function = tcp4_listen,
2821 .name = "tcp4-listen",
2822 /* Takes a vector of packets. */
2823 .vector_size = sizeof (u32),
2824 .n_errors = TCP_N_ERROR,
2825 .error_strings = tcp_error_strings,
2826 .n_next_nodes = TCP_LISTEN_N_NEXT,
2829 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2830 foreach_tcp_state_next
2833 .format_trace = format_tcp_rx_trace_short,
2837 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2840 VLIB_REGISTER_NODE (tcp6_listen_node) =
2842 .function = tcp6_listen,
2843 .name = "tcp6-listen",
2844 /* Takes a vector of packets. */
2845 .vector_size = sizeof (u32),
2846 .n_errors = TCP_N_ERROR,
2847 .error_strings = tcp_error_strings,
2848 .n_next_nodes = TCP_LISTEN_N_NEXT,
2851 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2852 foreach_tcp_state_next
2855 .format_trace = format_tcp_rx_trace_short,
2859 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2861 vlib_node_registration_t tcp4_input_node;
2862 vlib_node_registration_t tcp6_input_node;
2864 typedef enum _tcp_input_next
2866 TCP_INPUT_NEXT_DROP,
2867 TCP_INPUT_NEXT_LISTEN,
2868 TCP_INPUT_NEXT_RCV_PROCESS,
2869 TCP_INPUT_NEXT_SYN_SENT,
2870 TCP_INPUT_NEXT_ESTABLISHED,
2871 TCP_INPUT_NEXT_RESET,
2872 TCP_INPUT_NEXT_PUNT,
2876 #define foreach_tcp4_input_next \
2877 _ (DROP, "error-drop") \
2878 _ (LISTEN, "tcp4-listen") \
2879 _ (RCV_PROCESS, "tcp4-rcv-process") \
2880 _ (SYN_SENT, "tcp4-syn-sent") \
2881 _ (ESTABLISHED, "tcp4-established") \
2882 _ (RESET, "tcp4-reset") \
2883 _ (PUNT, "error-punt")
2885 #define foreach_tcp6_input_next \
2886 _ (DROP, "error-drop") \
2887 _ (LISTEN, "tcp6-listen") \
2888 _ (RCV_PROCESS, "tcp6-rcv-process") \
2889 _ (SYN_SENT, "tcp6-syn-sent") \
2890 _ (ESTABLISHED, "tcp6-established") \
2891 _ (RESET, "tcp6-reset") \
2892 _ (PUNT, "error-punt")
2894 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2897 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2898 vlib_frame_t * from_frame, int is_ip4)
2900 u32 n_left_from, next_index, *from, *to_next;
2901 u32 my_thread_index = vm->thread_index;
2902 tcp_main_t *tm = vnet_get_tcp_main ();
2904 from = vlib_frame_vector_args (from_frame);
2905 n_left_from = from_frame->n_vectors;
2906 next_index = node->cached_next_index;
2907 tcp_set_time_now (my_thread_index);
2909 while (n_left_from > 0)
2913 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2915 while (n_left_from > 0 && n_left_to_next > 0)
2917 int n_advance_bytes0, n_data_bytes0;
2920 tcp_header_t *tcp0 = 0;
2921 tcp_connection_t *tc0;
2922 transport_connection_t *tconn;
2925 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2933 n_left_to_next -= 1;
2935 b0 = vlib_get_buffer (vm, bi0);
2936 vnet_buffer (b0)->tcp.flags = 0;
2938 /* Checksum computed by ipx_local no need to compute again */
2942 ip40 = vlib_buffer_get_current (b0);
2943 tcp0 = ip4_next_header (ip40);
2944 n_advance_bytes0 = (ip4_header_bytes (ip40)
2945 + tcp_header_bytes (tcp0));
2946 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2948 tconn = stream_session_lookup_transport_wt4 (&ip40->dst_address,
2952 SESSION_TYPE_IP4_TCP,
2954 tc0 = tcp_get_connection_from_transport (tconn);
2955 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
2959 ip60 = vlib_buffer_get_current (b0);
2960 tcp0 = ip6_next_header (ip60);
2961 n_advance_bytes0 = tcp_header_bytes (tcp0);
2962 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2964 n_advance_bytes0 += sizeof (ip60[0]);
2965 tconn = stream_session_lookup_transport_wt6 (&ip60->dst_address,
2969 SESSION_TYPE_IP6_TCP,
2971 tc0 = tcp_get_connection_from_transport (tconn);
2972 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
2976 if (PREDICT_FALSE (n_advance_bytes0 < 0))
2978 error0 = TCP_ERROR_LENGTH;
2982 /* Session exists */
2983 if (PREDICT_TRUE (0 != tc0))
2985 /* Save connection index */
2986 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2987 vnet_buffer (b0)->tcp.seq_number =
2988 clib_net_to_host_u32 (tcp0->seq_number);
2989 vnet_buffer (b0)->tcp.ack_number =
2990 clib_net_to_host_u32 (tcp0->ack_number);
2992 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
2993 - (u8 *) vlib_buffer_get_current (b0);
2994 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
2995 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
2997 flags0 = tcp0->flags & filter_flags;
2998 next0 = tm->dispatch_table[tc0->state][flags0].next;
2999 error0 = tm->dispatch_table[tc0->state][flags0].error;
3001 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH
3002 || next0 == TCP_INPUT_NEXT_RESET))
3004 /* Overload tcp flags to store state */
3005 tcp_state_t state0 = tc0->state;
3006 vnet_buffer (b0)->tcp.flags = tc0->state;
3008 if (error0 == TCP_ERROR_DISPATCH)
3009 clib_warning ("disp error state %U flags %U",
3010 format_tcp_state, state0, format_tcp_flags,
3016 if ((is_ip4 && tm->punt_unknown4) ||
3017 (!is_ip4 && tm->punt_unknown6))
3019 next0 = TCP_INPUT_NEXT_PUNT;
3020 error0 = TCP_ERROR_PUNT;
3025 next0 = TCP_INPUT_NEXT_RESET;
3026 error0 = TCP_ERROR_NO_LISTENER;
3031 b0->error = error0 ? node->errors[error0] : 0;
3033 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3035 tcp_rx_trace_t *t0 =
3036 vlib_add_trace (vm, node, b0, sizeof (*t0));
3037 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3039 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
3040 n_left_to_next, bi0, next0);
3043 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3046 return from_frame->n_vectors;
3050 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3051 vlib_frame_t * from_frame)
3053 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3057 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3058 vlib_frame_t * from_frame)
3060 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3064 VLIB_REGISTER_NODE (tcp4_input_node) =
3066 .function = tcp4_input,
3067 .name = "tcp4-input",
3068 /* Takes a vector of packets. */
3069 .vector_size = sizeof (u32),
3070 .n_errors = TCP_N_ERROR,
3071 .error_strings = tcp_error_strings,
3072 .n_next_nodes = TCP_INPUT_N_NEXT,
3075 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3076 foreach_tcp4_input_next
3079 .format_buffer = format_tcp_header,
3080 .format_trace = format_tcp_rx_trace,
3084 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3087 VLIB_REGISTER_NODE (tcp6_input_node) =
3089 .function = tcp6_input,
3090 .name = "tcp6-input",
3091 /* Takes a vector of packets. */
3092 .vector_size = sizeof (u32),
3093 .n_errors = TCP_N_ERROR,
3094 .error_strings = tcp_error_strings,
3095 .n_next_nodes = TCP_INPUT_N_NEXT,
3098 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3099 foreach_tcp6_input_next
3102 .format_buffer = format_tcp_header,
3103 .format_trace = format_tcp_rx_trace,
3107 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3110 tcp_dispatch_table_init (tcp_main_t * tm)
3113 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3114 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3116 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3117 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3120 #define _(t,f,n,e) \
3122 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3123 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3126 /* SYNs for new connections -> tcp-listen. */
3127 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3128 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3129 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_NONE);
3130 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3132 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3133 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3134 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3135 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3136 /* SYN-ACK for a SYN */
3137 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3139 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3140 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3141 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3143 /* ACK for for established connection -> tcp-established. */
3144 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3145 /* FIN for for established connection -> tcp-established. */
3146 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3147 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3149 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3150 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3152 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3153 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3155 /* ACK or FIN-ACK to our FIN */
3156 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3157 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3159 /* FIN in reply to our FIN from the other side */
3160 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3161 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3162 /* FIN confirming that the peer (app) has closed */
3163 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3164 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3165 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3167 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3168 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3170 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3171 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3172 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3174 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3175 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3176 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3178 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3179 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3180 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3181 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3182 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3183 TCP_ERROR_CONNECTION_CLOSED);
3188 tcp_input_init (vlib_main_t * vm)
3190 clib_error_t *error = 0;
3191 tcp_main_t *tm = vnet_get_tcp_main ();
3193 if ((error = vlib_call_init_function (vm, tcp_init)))
3196 /* Initialize dispatch table. */
3197 tcp_dispatch_table_init (tm);
3202 VLIB_INIT_FUNCTION (tcp_input_init);
3205 * fd.io coding-style-patch-verification: ON
3208 * eval: (c-set-style "gnu")