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)
355 tcp_make_ack (tc0, b0);
357 tcp_make_synack (tc0, b0);
358 *next0 = tcp_next_output (tc0->c_is_ip4);
359 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
363 /* If segment in window, save timestamp */
364 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
365 vnet_buffer (b0)->tcp.seq_end);
370 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
372 /* SND.UNA =< SEG.ACK =< SND.NXT */
373 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
374 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
378 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
380 * Note that although the original article, srtt and rttvar are scaled
381 * to minimize round-off errors, here we don't. Instead, we rely on
382 * better precision time measurements.
384 * TODO support us rtt resolution
387 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
393 err = mrtt - tc->srtt;
395 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
396 * The increase should be bound */
397 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
398 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
399 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
403 /* First measurement. */
405 tc->rttvar = mrtt >> 1;
410 tcp_update_rto (tcp_connection_t * tc)
412 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
413 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
416 /** Update RTT estimate and RTO timer
418 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
419 * timing. Middle boxes are known to fiddle with TCP options so we
420 * should give higher priority to ACK timing.
422 * return 1 if valid rtt 0 otherwise
425 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
430 /* Determine if only rtx bytes are acked. */
431 rtx_acked = tcp_in_cong_recovery (tc) || !tc->bytes_acked;
433 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
434 * RTT because they're ambiguous. */
435 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq) && !rtx_acked)
437 mrtt = tcp_time_now () - tc->rtt_ts;
439 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
440 * snd_una, i.e., the left side of the send window:
441 * seq_lt (tc->snd_una, ack). */
442 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr
445 mrtt = tcp_time_now () - tc->rcv_opts.tsecr;
448 /* Allow measuring of a new RTT */
451 /* If ACK moves left side of the wnd make sure boff is 0, even if mrtt is
456 /* Ignore dubious measurements */
457 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
460 tcp_estimate_rtt (tc, mrtt);
467 * Dequeue bytes that have been acked and while at it update RTT estimates.
470 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
472 /* Dequeue the newly ACKed add SACKed bytes */
473 stream_session_dequeue_drop (&tc->connection,
474 tc->bytes_acked + tc->sack_sb.snd_una_adv);
476 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
478 /* Update rtt and rto */
479 tcp_update_rtt (tc, ack);
481 /* If everything has been acked, stop retransmit timer
482 * otherwise update. */
483 tcp_retransmit_timer_update (tc);
487 * Check if duplicate ack as per RFC5681 Sec. 2
490 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
493 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
494 && seq_gt (tc->snd_una_max, tc->snd_una)
495 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
496 && (prev_snd_wnd == tc->snd_wnd));
500 * Checks if ack is a congestion control event.
503 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
504 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
506 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
507 * defined to be 'duplicate' */
508 *is_dack = tc->sack_sb.last_sacked_bytes
509 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
511 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
515 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
517 sack_scoreboard_hole_t *next, *prev;
519 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
521 next = pool_elt_at_index (sb->holes, hole->next);
522 next->prev = hole->prev;
526 sb->tail = hole->prev;
529 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
531 prev = pool_elt_at_index (sb->holes, hole->prev);
532 prev->next = hole->next;
536 sb->head = hole->next;
539 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
540 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
542 /* Poison the entry */
544 memset (hole, 0xfe, sizeof (*hole));
546 pool_put (sb->holes, hole);
549 sack_scoreboard_hole_t *
550 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
553 sack_scoreboard_hole_t *hole, *next, *prev;
556 pool_get (sb->holes, hole);
557 memset (hole, 0, sizeof (*hole));
561 hole_index = scoreboard_hole_index (sb, hole);
563 prev = scoreboard_get_hole (sb, prev_index);
566 hole->prev = prev_index;
567 hole->next = prev->next;
569 if ((next = scoreboard_next_hole (sb, hole)))
570 next->prev = hole_index;
572 sb->tail = hole_index;
574 prev->next = hole_index;
578 sb->head = hole_index;
579 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
580 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
587 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
589 sack_scoreboard_hole_t *hole, *prev;
590 u32 bytes = 0, blks = 0;
593 sb->sacked_bytes = 0;
594 hole = scoreboard_last_hole (sb);
598 if (seq_gt (sb->high_sacked, hole->end))
600 bytes = sb->high_sacked - hole->end;
604 while ((prev = scoreboard_prev_hole (sb, hole))
605 && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
606 && blks < TCP_DUPACK_THRESHOLD))
608 bytes += hole->start - prev->end;
615 sb->lost_bytes += scoreboard_hole_bytes (hole);
618 hole = scoreboard_prev_hole (sb, hole);
620 bytes += prev->start - hole->end;
622 sb->sacked_bytes = bytes;
626 * Figure out the next hole to retransmit
628 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
630 sack_scoreboard_hole_t *
631 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
632 sack_scoreboard_hole_t * start,
634 u8 * can_rescue, u8 * snd_limited)
636 sack_scoreboard_hole_t *hole = 0;
638 hole = start ? start : scoreboard_first_hole (sb);
639 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
640 hole = scoreboard_next_hole (sb, hole);
642 /* Nothing, return */
645 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
649 /* Rule (1): if higher than rxt, less than high_sacked and lost */
650 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
652 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
656 /* Rule (2): output takes care of transmitting new data */
657 if (!have_sent_1_smss)
660 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
662 /* Rule (3): if hole not lost */
663 else if (seq_lt (hole->start, sb->high_sacked))
666 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
668 /* Rule (4): if hole beyond high_sacked */
671 ASSERT (seq_geq (hole->start, sb->high_sacked));
674 /* HighRxt MUST NOT be updated */
679 if (hole && seq_lt (sb->high_rxt, hole->start))
680 sb->high_rxt = hole->start;
686 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
688 sack_scoreboard_hole_t *hole;
689 hole = scoreboard_first_hole (sb);
692 seq = seq_gt (seq, hole->start) ? seq : hole->start;
693 sb->cur_rxt_hole = sb->head;
699 * Test that scoreboard is sane after recovery
701 * Returns 1 if scoreboard is empty or if first hole beyond
705 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
707 sack_scoreboard_hole_t *hole;
708 hole = scoreboard_first_hole (&tc->sack_sb);
709 return (!hole || seq_geq (hole->start, tc->snd_una));
713 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
715 sack_scoreboard_t *sb = &tc->sack_sb;
716 sack_block_t *blk, tmp;
717 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
718 u32 blk_index = 0, old_sacked_bytes, hole_index;
721 sb->last_sacked_bytes = 0;
723 old_sacked_bytes = sb->sacked_bytes;
724 sb->last_bytes_delivered = 0;
726 if (!tcp_opts_sack (&tc->rcv_opts)
727 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
730 /* Remove invalid blocks */
731 blk = tc->rcv_opts.sacks;
732 while (blk < vec_end (tc->rcv_opts.sacks))
734 if (seq_lt (blk->start, blk->end)
735 && seq_gt (blk->start, tc->snd_una)
736 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
741 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
744 /* Add block for cumulative ack */
745 if (seq_gt (ack, tc->snd_una))
747 tmp.start = tc->snd_una;
749 vec_add1 (tc->rcv_opts.sacks, tmp);
752 if (vec_len (tc->rcv_opts.sacks) == 0)
755 tcp_scoreboard_trace_add (tc, ack);
757 /* Make sure blocks are ordered */
758 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
759 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
760 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
762 tmp = tc->rcv_opts.sacks[i];
763 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
764 tc->rcv_opts.sacks[j] = tmp;
767 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
769 /* If no holes, insert the first that covers all outstanding bytes */
770 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
771 tc->snd_una, tc->snd_una_max);
772 sb->tail = scoreboard_hole_index (sb, last_hole);
773 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
774 sb->high_sacked = tmp.end;
778 /* If we have holes but snd_una_max is beyond the last hole, update
780 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
781 last_hole = scoreboard_last_hole (sb);
782 if (seq_gt (tc->snd_una_max, last_hole->end))
784 if (seq_geq (last_hole->start, sb->high_sacked))
786 last_hole->end = tc->snd_una_max;
788 /* New hole after high sacked block */
789 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
791 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
795 /* Keep track of max byte sacked for when the last hole
797 if (seq_gt (tmp.end, sb->high_sacked))
798 sb->high_sacked = tmp.end;
801 /* Walk the holes with the SACK blocks */
802 hole = pool_elt_at_index (sb->holes, sb->head);
803 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
805 blk = &tc->rcv_opts.sacks[blk_index];
806 if (seq_leq (blk->start, hole->start))
808 /* Block covers hole. Remove hole */
809 if (seq_geq (blk->end, hole->end))
811 next_hole = scoreboard_next_hole (sb, hole);
813 /* Byte accounting: snd_una needs to be advanced */
818 if (seq_lt (ack, next_hole->start))
819 sb->snd_una_adv = next_hole->start - ack;
820 sb->last_bytes_delivered +=
821 next_hole->start - hole->end;
825 ASSERT (seq_geq (sb->high_sacked, ack));
826 sb->snd_una_adv = sb->high_sacked - ack;
827 sb->last_bytes_delivered += sb->high_sacked - hole->end;
831 scoreboard_remove_hole (sb, hole);
834 /* Partial 'head' overlap */
837 if (seq_gt (blk->end, hole->start))
839 hole->start = blk->end;
846 /* Hole must be split */
847 if (seq_lt (blk->end, hole->end))
849 hole_index = scoreboard_hole_index (sb, hole);
850 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
853 /* Pool might've moved */
854 hole = scoreboard_get_hole (sb, hole_index);
855 hole->end = blk->start;
857 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
859 else if (seq_lt (blk->start, hole->end))
861 hole->end = blk->start;
863 hole = scoreboard_next_hole (sb, hole);
867 scoreboard_update_bytes (tc, sb);
868 sb->last_sacked_bytes = sb->sacked_bytes
869 - (old_sacked_bytes - sb->last_bytes_delivered);
870 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes);
871 ASSERT (sb->sacked_bytes == 0
872 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
873 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
874 - seq_max (tc->snd_una, ack));
875 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
876 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
880 * Try to update snd_wnd based on feedback received from peer.
882 * If successful, and new window is 'effectively' 0, activate persist
886 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
888 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
889 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
890 if (seq_lt (tc->snd_wl1, seq)
891 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
893 tc->snd_wnd = snd_wnd;
896 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
898 if (tc->snd_wnd < tc->snd_mss)
900 /* Set persist timer if not set and we just got 0 wnd */
901 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
902 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
903 tcp_persist_timer_set (tc);
907 tcp_persist_timer_reset (tc);
908 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
918 tcp_cc_init_congestion (tcp_connection_t * tc)
920 tcp_fastrecovery_on (tc);
921 tc->snd_congestion = tc->snd_una_max;
922 tc->cc_algo->congestion (tc);
923 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
927 tcp_cc_recovery_exit (tcp_connection_t * tc)
933 tcp_recovery_off (tc);
937 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
939 tc->cc_algo->recovered (tc);
940 tc->snd_rxt_bytes = 0;
942 tcp_fastrecovery_off (tc);
943 tcp_fastrecovery_1_smss_off (tc);
947 tcp_cc_congestion_undo (tcp_connection_t * tc)
949 tc->cwnd = tc->prev_cwnd;
950 tc->ssthresh = tc->prev_ssthresh;
951 tc->snd_nxt = tc->snd_una_max;
953 if (tcp_in_recovery (tc))
954 tcp_cc_recovery_exit (tc);
955 ASSERT (tc->rto_boff == 0);
956 /* TODO extend for fastrecovery */
960 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
962 return (tcp_in_recovery (tc)
964 && tcp_opts_tstamp (&tc->rcv_opts)
965 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
969 tcp_cc_recover (tcp_connection_t * tc)
971 ASSERT (tcp_in_cong_recovery (tc));
972 if (tcp_cc_is_spurious_retransmit (tc))
974 tcp_cc_congestion_undo (tc);
978 if (tcp_in_recovery (tc))
979 tcp_cc_recovery_exit (tc);
980 else if (tcp_in_fastrecovery (tc))
981 tcp_cc_fastrecovery_exit (tc);
983 ASSERT (tc->rto_boff == 0);
984 ASSERT (!tcp_in_cong_recovery (tc));
985 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
986 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
991 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
993 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
995 /* Congestion avoidance */
996 tc->cc_algo->rcv_ack (tc);
997 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
999 /* If a cumulative ack, make sure dupacks is 0 */
1000 tc->rcv_dupacks = 0;
1002 /* When dupacks hits the threshold we only enter fast retransmit if
1003 * cumulative ack covers more than snd_congestion. Should snd_una
1004 * wrap this test may fail under otherwise valid circumstances.
1005 * Therefore, proactively update snd_congestion when wrap detected. */
1007 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1008 && seq_gt (tc->snd_congestion, tc->snd_una)))
1009 tc->snd_congestion = tc->snd_una - 1;
1013 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1015 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1019 tcp_should_fastrecover (tcp_connection_t * tc)
1021 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1022 || tcp_should_fastrecover_sack (tc));
1026 * One function to rule them all ... and in the darkness bind them
1029 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1034 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1035 * it account for the bytes that left the network.
1039 ASSERT (tc->snd_una != tc->snd_una_max
1040 || tc->sack_sb.last_sacked_bytes);
1044 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1046 ASSERT (tcp_in_fastrecovery (tc));
1047 /* Pure duplicate ack. If some data got acked, it's handled lower */
1048 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1051 else if (tcp_should_fastrecover (tc))
1053 /* Things are already bad */
1054 if (tcp_in_cong_recovery (tc))
1056 tc->rcv_dupacks = 0;
1057 goto partial_ack_test;
1060 /* If of of the two conditions lower hold, reset dupacks because
1061 * we're probably after timeout (RFC6582 heuristics).
1062 * If Cumulative ack does not cover more than congestion threshold,
1064 * 1) The following doesn't hold: The congestion window is greater
1065 * than SMSS bytes and the difference between highest_ack
1066 * and prev_highest_ack is at most 4*SMSS bytes
1067 * 2) Echoed timestamp in the last non-dup ack does not equal the
1070 if (seq_leq (tc->snd_una, tc->snd_congestion)
1071 && ((!(tc->cwnd > tc->snd_mss
1072 && tc->bytes_acked <= 4 * tc->snd_mss))
1073 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1075 tc->rcv_dupacks = 0;
1079 tcp_cc_init_congestion (tc);
1080 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1082 /* The first segment MUST be retransmitted */
1083 tcp_retransmit_first_unacked (tc);
1085 /* Post retransmit update cwnd to ssthresh and account for the
1086 * three segments that have left the network and should've been
1087 * buffered at the receiver XXX */
1088 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1089 ASSERT (tc->cwnd >= tc->snd_mss);
1091 /* If cwnd allows, send more data */
1092 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1094 scoreboard_init_high_rxt (&tc->sack_sb,
1095 tc->snd_una + tc->snd_mss);
1096 tcp_fast_retransmit_sack (tc);
1100 tcp_fast_retransmit_no_sack (tc);
1105 else if (!tc->bytes_acked
1106 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1108 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1117 if (!tc->bytes_acked)
1122 * Legitimate ACK. 1) See if we can exit recovery
1124 /* XXX limit this only to first partial ack? */
1125 tcp_retransmit_timer_update (tc);
1127 if (seq_geq (tc->snd_una, tc->snd_congestion))
1129 /* If spurious return, we've already updated everything */
1130 if (tcp_cc_recover (tc))
1132 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1136 tc->snd_nxt = tc->snd_una_max;
1138 /* Treat as congestion avoidance ack */
1139 tc->cc_algo->rcv_ack (tc);
1140 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1145 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1147 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1149 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1150 * reset dupacks to 0 */
1151 tc->rcv_dupacks = 0;
1153 tcp_retransmit_first_unacked (tc);
1155 /* Post RTO timeout don't try anything fancy */
1156 if (tcp_in_recovery (tc))
1159 /* Remove retransmitted bytes that have been delivered */
1160 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1161 >= tc->sack_sb.last_bytes_delivered
1162 || (tc->flags & TCP_CONN_FINSNT));
1164 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1166 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1167 * remove sacked bytes delivered */
1168 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1169 - tc->sack_sb.last_bytes_delivered;
1170 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1171 tc->snd_rxt_bytes -= rxt_delivered;
1175 /* Either all retransmitted holes have been acked, or we're
1176 * "in the blind" and retransmitting segment by segment */
1177 tc->snd_rxt_bytes = 0;
1180 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1183 * Since this was a partial ack, try to retransmit some more data
1185 tcp_fast_retransmit (tc);
1189 tcp_cc_init (tcp_connection_t * tc)
1191 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
1192 tc->cc_algo->init (tc);
1196 * Process incoming ACK
1199 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1200 tcp_header_t * th, u32 * next, u32 * error)
1202 u32 prev_snd_wnd, prev_snd_una;
1205 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1207 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1208 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1210 /* If we have outstanding data and this is within the window, accept it,
1211 * probably retransmit has timed out. Otherwise ACK segment and then
1213 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1215 tcp_make_ack (tc, b);
1216 *next = tcp_next_output (tc->c_is_ip4);
1217 *error = TCP_ERROR_ACK_INVALID;
1218 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1219 vnet_buffer (b)->tcp.ack_number);
1223 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1224 vnet_buffer (b)->tcp.ack_number);
1226 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1227 *error = TCP_ERROR_ACK_FUTURE;
1230 /* If old ACK, probably it's an old dupack */
1231 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1233 *error = TCP_ERROR_ACK_OLD;
1234 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1235 vnet_buffer (b)->tcp.ack_number);
1236 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1238 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
1239 tcp_cc_handle_event (tc, 1);
1241 /* Don't drop yet */
1246 * Looks okay, process feedback
1249 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1250 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1252 prev_snd_wnd = tc->snd_wnd;
1253 prev_snd_una = tc->snd_una;
1254 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1255 vnet_buffer (b)->tcp.ack_number,
1256 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1257 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1258 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1259 tcp_validate_txf_size (tc, tc->bytes_acked);
1261 if (tc->bytes_acked)
1262 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1264 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1267 * Check if we have congestion event
1270 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1272 tcp_cc_handle_event (tc, is_dack);
1273 if (!tcp_in_cong_recovery (tc))
1275 *error = TCP_ERROR_ACK_DUP;
1276 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1277 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1281 * Update congestion control (slow start/congestion avoidance)
1283 tcp_cc_update (tc, b);
1289 tcp_sack_vector_is_sane (sack_block_t * sacks)
1292 for (i = 1; i < vec_len (sacks); i++)
1294 if (sacks[i - 1].end == sacks[i].start)
1301 * Build SACK list as per RFC2018.
1303 * Makes sure the first block contains the segment that generated the current
1304 * ACK and the following ones are the ones most recently reported in SACK
1307 * @param tc TCP connection for which the SACK list is updated
1308 * @param start Start sequence number of the newest SACK block
1309 * @param end End sequence of the newest SACK block
1312 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1314 sack_block_t *new_list = 0, *block = 0;
1317 /* If the first segment is ooo add it to the list. Last write might've moved
1318 * rcv_nxt over the first segment. */
1319 if (seq_lt (tc->rcv_nxt, start))
1321 vec_add2 (new_list, block, 1);
1322 block->start = start;
1326 /* Find the blocks still worth keeping. */
1327 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1329 /* Discard if rcv_nxt advanced beyond current block */
1330 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1333 /* Merge or drop if segment overlapped by the new segment */
1334 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1335 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1337 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1338 new_list[0].start = tc->snd_sacks[i].start;
1339 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1340 new_list[0].end = tc->snd_sacks[i].end;
1344 /* Save to new SACK list if we have space. */
1345 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1347 vec_add1 (new_list, tc->snd_sacks[i]);
1351 clib_warning ("sack discarded");
1355 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1357 /* Replace old vector with new one */
1358 vec_free (tc->snd_sacks);
1359 tc->snd_sacks = new_list;
1361 /* Segments should not 'touch' */
1362 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1365 /** Enqueue data for delivery to application */
1367 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1370 int written, error = TCP_ERROR_ENQUEUED;
1372 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1374 /* Pure ACK. Update rcv_nxt and be done. */
1375 if (PREDICT_FALSE (data_len == 0))
1377 return TCP_ERROR_PURE_ACK;
1380 written = stream_session_enqueue_data (&tc->connection, b, 0,
1381 1 /* queue event */ , 1);
1383 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1385 /* Update rcv_nxt */
1386 if (PREDICT_TRUE (written == data_len))
1388 tc->rcv_nxt += written;
1390 /* If more data written than expected, account for out-of-order bytes. */
1391 else if (written > data_len)
1393 tc->rcv_nxt += written;
1395 /* Send ACK confirming the update */
1396 tc->flags |= TCP_CONN_SNDACK;
1398 else if (written > 0)
1400 /* We've written something but FIFO is probably full now */
1401 tc->rcv_nxt += written;
1403 /* Depending on how fast the app is, all remaining buffers in burst will
1404 * not be enqueued. Inform peer */
1405 tc->flags |= TCP_CONN_SNDACK;
1407 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1411 tc->flags |= TCP_CONN_SNDACK;
1412 return TCP_ERROR_FIFO_FULL;
1415 /* Update SACK list if need be */
1416 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1418 /* Remove SACK blocks that have been delivered */
1419 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1425 /** Enqueue out-of-order data */
1427 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1430 stream_session_t *s0;
1433 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1435 /* Pure ACK. Do nothing */
1436 if (PREDICT_FALSE (data_len == 0))
1438 return TCP_ERROR_PURE_ACK;
1441 /* Enqueue out-of-order data with relative offset */
1442 rv = stream_session_enqueue_data (&tc->connection, b,
1443 vnet_buffer (b)->tcp.seq_number -
1444 tc->rcv_nxt, 0 /* queue event */ , 0);
1446 /* Nothing written */
1449 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1450 return TCP_ERROR_FIFO_FULL;
1453 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1455 /* Update SACK list if in use */
1456 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1458 ooo_segment_t *newest;
1461 s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
1463 /* Get the newest segment from the fifo */
1464 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1467 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1468 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1469 start = tc->rcv_nxt + offset;
1470 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1471 tcp_update_sack_list (tc, start, end);
1472 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1476 return TCP_ERROR_ENQUEUED;
1480 * Check if ACK could be delayed. If ack can be delayed, it should return
1481 * true for a full frame. If we're always acking return 0.
1484 tcp_can_delack (tcp_connection_t * tc)
1486 /* Send ack if ... */
1488 /* just sent a rcv wnd 0 */
1489 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1490 /* constrained to send ack */
1491 || (tc->flags & TCP_CONN_SNDACK) != 0
1492 /* we're almost out of tx wnd */
1493 || tcp_available_snd_space (tc) < 4 * tc->snd_mss)
1500 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1502 u32 discard, first = b->current_length;
1503 vlib_main_t *vm = vlib_get_main ();
1505 /* Handle multi-buffer segments */
1506 if (n_bytes_to_drop > b->current_length)
1508 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1512 discard = clib_min (n_bytes_to_drop, b->current_length);
1513 vlib_buffer_advance (b, discard);
1514 b = vlib_get_buffer (vm, b->next_buffer);
1515 n_bytes_to_drop -= discard;
1517 while (n_bytes_to_drop);
1518 if (n_bytes_to_drop > first)
1519 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1522 vlib_buffer_advance (b, n_bytes_to_drop);
1523 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1528 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1531 u32 error = 0, n_bytes_to_drop, n_data_bytes;
1533 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1534 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1535 ASSERT (n_data_bytes);
1537 /* Handle out-of-order data */
1538 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1540 /* Old sequence numbers allowed through because they overlapped
1542 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1544 error = TCP_ERROR_SEGMENT_OLD;
1545 *next0 = TCP_NEXT_DROP;
1547 /* Completely in the past (possible retransmit) */
1548 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1550 /* Ack retransmissions since we may not have any data to send */
1551 tcp_make_ack (tc, b);
1552 *next0 = tcp_next_output (tc->c_is_ip4);
1556 /* Chop off the bytes in the past */
1557 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1558 n_data_bytes -= n_bytes_to_drop;
1559 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1560 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1566 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1568 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1569 * cwnd on remote peer when congested 2) acks leaving should have the
1570 * latest rcv_wnd since the burst may eaten up all of it, so only the
1571 * old ones could be filtered.
1574 /* RFC2581: Send DUPACK for fast retransmit */
1575 tcp_make_ack (tc, b);
1576 *next0 = tcp_next_output (tc->c_is_ip4);
1578 /* Mark as DUPACK. We may filter these in output if
1579 * the burst fills the holes. */
1581 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1583 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1589 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1590 * segments can be enqueued after fifo tail offset changes. */
1591 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1593 /* Check if ACK can be delayed */
1594 if (tcp_can_delack (tc))
1596 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1597 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1601 *next0 = tcp_next_output (tc->c_is_ip4);
1602 tcp_make_ack (tc, b);
1610 tcp_header_t tcp_header;
1611 tcp_connection_t tcp_connection;
1615 format_tcp_rx_trace (u8 * s, va_list * args)
1617 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1618 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1619 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1620 uword indent = format_get_indent (s);
1622 s = format (s, "%U\n%U%U",
1623 format_tcp_header, &t->tcp_header, 128,
1624 format_white_space, indent,
1625 format_tcp_connection, &t->tcp_connection, 1);
1631 format_tcp_rx_trace_short (u8 * s, va_list * args)
1633 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1634 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1635 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1637 s = format (s, "%d -> %d (%U)",
1638 clib_net_to_host_u16 (t->tcp_header.src_port),
1639 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1640 t->tcp_connection.state);
1646 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1647 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1651 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1655 th0 = tcp_buffer_hdr (b0);
1657 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1661 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1663 if (PREDICT_TRUE (!val))
1667 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1669 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1673 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1674 vlib_frame_t * from_frame, int is_ip4)
1676 u32 n_left_from, next_index, *from, *to_next;
1677 u32 my_thread_index = vm->thread_index, errors = 0;
1678 tcp_main_t *tm = vnet_get_tcp_main ();
1681 from = vlib_frame_vector_args (from_frame);
1682 n_left_from = from_frame->n_vectors;
1684 next_index = node->cached_next_index;
1686 while (n_left_from > 0)
1690 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1691 while (n_left_from > 0 && n_left_to_next > 0)
1695 tcp_header_t *th0 = 0;
1696 tcp_connection_t *tc0;
1697 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1704 n_left_to_next -= 1;
1706 b0 = vlib_get_buffer (vm, bi0);
1707 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1710 if (PREDICT_FALSE (tc0 == 0))
1712 error0 = TCP_ERROR_INVALID_CONNECTION;
1716 th0 = tcp_buffer_hdr (b0);
1717 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1718 * dangling reference. */
1719 is_fin = tcp_is_fin (th0);
1721 /* SYNs, FINs and data consume sequence numbers */
1722 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1723 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1725 /* TODO header prediction fast path */
1727 /* 1-4: check SEQ, RST, SYN */
1728 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1730 error0 = TCP_ERROR_SEGMENT_INVALID;
1731 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1732 vnet_buffer (b0)->tcp.seq_number,
1733 vnet_buffer (b0)->tcp.seq_end);
1737 /* 5: check the ACK field */
1738 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1741 /* 6: check the URG bit TODO */
1743 /* 7: process the segment text */
1744 if (vnet_buffer (b0)->tcp.data_len)
1745 error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
1747 /* 8: check the FIN bit */
1748 if (PREDICT_FALSE (is_fin))
1750 /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
1751 * wait for session to call close. To avoid lingering
1752 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1753 tc0->state = TCP_STATE_CLOSE_WAIT;
1754 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1755 if (vnet_buffer (b0)->tcp.data_len == 0)
1758 next0 = TCP_ESTABLISHED_NEXT_DROP;
1760 stream_session_disconnect_notify (&tc0->connection);
1761 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1765 b0->error = node->errors[error0];
1766 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1768 tcp_rx_trace_t *t0 =
1769 vlib_add_trace (vm, node, b0, sizeof (*t0));
1770 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1773 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1774 n_left_to_next, bi0, next0);
1777 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1780 errors = session_manager_flush_enqueue_events (my_thread_index);
1781 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1782 tcp_flush_frame_to_output (vm, my_thread_index, is_ip4);
1784 return from_frame->n_vectors;
1788 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1789 vlib_frame_t * from_frame)
1791 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1795 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1796 vlib_frame_t * from_frame)
1798 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1802 VLIB_REGISTER_NODE (tcp4_established_node) =
1804 .function = tcp4_established,
1805 .name = "tcp4-established",
1806 /* Takes a vector of packets. */
1807 .vector_size = sizeof (u32),
1808 .n_errors = TCP_N_ERROR,
1809 .error_strings = tcp_error_strings,
1810 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1813 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1814 foreach_tcp_state_next
1817 .format_trace = format_tcp_rx_trace_short,
1821 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1824 VLIB_REGISTER_NODE (tcp6_established_node) =
1826 .function = tcp6_established,
1827 .name = "tcp6-established",
1828 /* Takes a vector of packets. */
1829 .vector_size = sizeof (u32),
1830 .n_errors = TCP_N_ERROR,
1831 .error_strings = tcp_error_strings,
1832 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1835 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1836 foreach_tcp_state_next
1839 .format_trace = format_tcp_rx_trace_short,
1844 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1846 vlib_node_registration_t tcp4_syn_sent_node;
1847 vlib_node_registration_t tcp6_syn_sent_node;
1850 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
1852 transport_connection_t *tmp;
1856 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
1857 && (tc->state == TCP_STATE_LISTEN
1858 || tc->c_rmt_port == hdr->src_port));
1863 stream_session_half_open_lookup (&tc->c_lcl_ip, &tc->c_rmt_ip,
1864 tc->c_lcl_port, tc->c_rmt_port,
1865 tc->c_transport_proto)))
1867 if (tmp->lcl_port == hdr->dst_port
1868 && tmp->rmt_port == hdr->src_port)
1870 clib_warning ("half-open is valid!");
1878 * Lookup transport connection
1880 static tcp_connection_t *
1881 tcp_lookup_connection (vlib_buffer_t * b, u8 thread_index, u8 is_ip4)
1884 transport_connection_t *tconn;
1885 tcp_connection_t *tc;
1889 ip4 = vlib_buffer_get_current (b);
1890 tcp = ip4_next_header (ip4);
1891 tconn = stream_session_lookup_transport_wt4 (&ip4->dst_address,
1895 SESSION_TYPE_IP4_TCP,
1897 tc = tcp_get_connection_from_transport (tconn);
1898 ASSERT (tcp_lookup_is_valid (tc, tcp));
1903 ip6 = vlib_buffer_get_current (b);
1904 tcp = ip6_next_header (ip6);
1905 tconn = stream_session_lookup_transport_wt6 (&ip6->dst_address,
1909 SESSION_TYPE_IP6_TCP,
1911 tc = tcp_get_connection_from_transport (tconn);
1912 ASSERT (tcp_lookup_is_valid (tc, tcp));
1918 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1919 vlib_frame_t * from_frame, int is_ip4)
1921 tcp_main_t *tm = vnet_get_tcp_main ();
1922 u32 n_left_from, next_index, *from, *to_next;
1923 u32 my_thread_index = vm->thread_index, errors = 0;
1925 from = vlib_frame_vector_args (from_frame);
1926 n_left_from = from_frame->n_vectors;
1928 next_index = node->cached_next_index;
1930 while (n_left_from > 0)
1934 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1936 while (n_left_from > 0 && n_left_to_next > 0)
1938 u32 bi0, ack0, seq0;
1941 tcp_header_t *tcp0 = 0;
1942 tcp_connection_t *tc0;
1943 tcp_connection_t *new_tc0;
1944 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1951 n_left_to_next -= 1;
1953 b0 = vlib_get_buffer (vm, bi0);
1955 tcp_half_open_connection_get (vnet_buffer (b0)->
1956 tcp.connection_index);
1957 if (PREDICT_FALSE (tc0 == 0))
1959 error0 = TCP_ERROR_INVALID_CONNECTION;
1963 /* Half-open completed recently but the connection was't removed
1964 * yet by the owning thread */
1965 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
1967 /* Make sure the connection actually exists */
1968 ASSERT (tcp_lookup_connection (b0, my_thread_index, is_ip4));
1972 ack0 = vnet_buffer (b0)->tcp.ack_number;
1973 seq0 = vnet_buffer (b0)->tcp.seq_number;
1974 tcp0 = tcp_buffer_hdr (b0);
1977 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1980 /* SYNs, FINs and data consume sequence numbers */
1981 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1982 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
1985 * 1. check the ACK bit
1989 * If the ACK bit is set
1990 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
1991 * the RST bit is set, if so drop the segment and return)
1992 * <SEQ=SEG.ACK><CTL=RST>
1993 * and discard the segment. Return.
1994 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
1998 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2000 clib_warning ("ack not in rcv wnd");
2001 if (!tcp_rst (tcp0))
2002 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2006 /* Make sure ACK is valid */
2007 if (seq_gt (tc0->snd_una, ack0))
2009 clib_warning ("ack invalid");
2015 * 2. check the RST bit
2020 /* If ACK is acceptable, signal client that peer is not
2021 * willing to accept connection and drop connection*/
2023 tcp_connection_reset (tc0);
2028 * 3. check the security and precedence (skipped)
2032 * 4. check the SYN bit
2035 /* No SYN flag. Drop. */
2036 if (!tcp_syn (tcp0))
2038 clib_warning ("not synack");
2043 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2045 clib_warning ("options parse fail");
2049 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2050 * current thread pool. */
2051 pool_get (tm->connections[my_thread_index], new_tc0);
2052 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2053 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2054 new_tc0->c_thread_index = my_thread_index;
2055 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2056 new_tc0->irs = seq0;
2057 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2058 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2059 TCP_TIMER_HANDLE_INVALID;
2061 /* If this is not the owning thread, wait for syn retransmit to
2062 * expire and cleanup then */
2063 if (tcp_half_open_connection_cleanup (tc0))
2064 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2066 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2068 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2069 new_tc0->tsval_recent_age = tcp_time_now ();
2072 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2073 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2075 /* RFC1323: SYN and SYN-ACK wnd not scaled */
2076 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
2077 new_tc0->snd_wl1 = seq0;
2078 new_tc0->snd_wl2 = ack0;
2080 tcp_connection_init_vars (new_tc0);
2082 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2083 if (PREDICT_TRUE (tcp_ack (tcp0)))
2085 /* Our SYN is ACKed: we have iss < ack = snd_una */
2087 /* TODO Dequeue acknowledged segments if we support Fast Open */
2088 new_tc0->snd_una = ack0;
2089 new_tc0->state = TCP_STATE_ESTABLISHED;
2091 /* Make sure las is initialized for the wnd computation */
2092 new_tc0->rcv_las = new_tc0->rcv_nxt;
2094 /* Notify app that we have connection. If session layer can't
2095 * allocate session send reset */
2096 if (stream_session_connect_notify (&new_tc0->connection, 0))
2098 clib_warning ("connect notify fail");
2099 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2100 tcp_connection_cleanup (new_tc0);
2104 /* Make sure after data segment processing ACK is sent */
2105 new_tc0->flags |= TCP_CONN_SNDACK;
2107 /* Update rtt with the syn-ack sample */
2108 new_tc0->bytes_acked = 1;
2109 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2110 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2112 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2115 new_tc0->state = TCP_STATE_SYN_RCVD;
2117 /* Notify app that we have connection */
2118 if (stream_session_connect_notify (&new_tc0->connection, 0))
2120 tcp_connection_cleanup (new_tc0);
2121 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2122 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2127 tcp_init_snd_vars (tc0);
2128 tcp_make_synack (new_tc0, b0);
2129 next0 = tcp_next_output (is_ip4);
2134 /* Read data, if any */
2135 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2138 error0 = tcp_segment_rcv (tm, new_tc0, b0, &next0);
2139 if (error0 == TCP_ERROR_PURE_ACK)
2140 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2144 tcp_make_ack (new_tc0, b0);
2145 next0 = tcp_next_output (new_tc0->c_is_ip4);
2150 b0->error = error0 ? node->errors[error0] : 0;
2151 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2153 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2154 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2155 clib_memcpy (&t0->tcp_connection, tc0,
2156 sizeof (t0->tcp_connection));
2159 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2160 n_left_to_next, bi0, next0);
2163 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2166 errors = session_manager_flush_enqueue_events (my_thread_index);
2170 vlib_node_increment_counter (vm, tcp4_established_node.index,
2171 TCP_ERROR_EVENT_FIFO_FULL, errors);
2173 vlib_node_increment_counter (vm, tcp6_established_node.index,
2174 TCP_ERROR_EVENT_FIFO_FULL, errors);
2177 return from_frame->n_vectors;
2181 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2182 vlib_frame_t * from_frame)
2184 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2188 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2189 vlib_frame_t * from_frame)
2191 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2195 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2197 .function = tcp4_syn_sent,
2198 .name = "tcp4-syn-sent",
2199 /* Takes a vector of packets. */
2200 .vector_size = sizeof (u32),
2201 .n_errors = TCP_N_ERROR,
2202 .error_strings = tcp_error_strings,
2203 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2206 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2207 foreach_tcp_state_next
2210 .format_trace = format_tcp_rx_trace_short,
2214 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2217 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2219 .function = tcp6_syn_sent_rcv,
2220 .name = "tcp6-syn-sent",
2221 /* Takes a vector of packets. */
2222 .vector_size = sizeof (u32),
2223 .n_errors = TCP_N_ERROR,
2224 .error_strings = tcp_error_strings,
2225 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2228 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2229 foreach_tcp_state_next
2232 .format_trace = format_tcp_rx_trace_short,
2236 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2239 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2240 * as per RFC793 p. 64
2243 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2244 vlib_frame_t * from_frame, int is_ip4)
2246 tcp_main_t *tm = vnet_get_tcp_main ();
2247 u32 n_left_from, next_index, *from, *to_next;
2248 u32 my_thread_index = vm->thread_index, errors = 0;
2250 from = vlib_frame_vector_args (from_frame);
2251 n_left_from = from_frame->n_vectors;
2253 next_index = node->cached_next_index;
2255 while (n_left_from > 0)
2259 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2261 while (n_left_from > 0 && n_left_to_next > 0)
2265 tcp_header_t *tcp0 = 0;
2266 tcp_connection_t *tc0;
2267 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
2274 n_left_to_next -= 1;
2276 b0 = vlib_get_buffer (vm, bi0);
2277 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2279 if (PREDICT_FALSE (tc0 == 0))
2281 error0 = TCP_ERROR_INVALID_CONNECTION;
2285 tcp0 = tcp_buffer_hdr (b0);
2287 /* SYNs, FINs and data consume sequence numbers */
2288 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2289 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0)
2290 + vnet_buffer (b0)->tcp.data_len;
2294 tcp_connection_t *tmp;
2295 tmp = tcp_lookup_connection (b0, my_thread_index, is_ip4);
2296 if (tmp->state != tc0->state)
2298 clib_warning ("state changed");
2305 * Special treatment for CLOSED
2309 case TCP_STATE_CLOSED:
2315 * For all other states (except LISTEN)
2318 /* 1-4: check SEQ, RST, SYN */
2319 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2322 error0 = TCP_ERROR_SEGMENT_INVALID;
2326 /* 5: check the ACK field */
2329 case TCP_STATE_SYN_RCVD:
2331 * If the segment acknowledgment is not acceptable, form a
2333 * <SEQ=SEG.ACK><CTL=RST>
2336 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2338 clib_warning ("connection not accepted");
2339 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2343 /* Update rtt and rto */
2344 tc0->bytes_acked = 1;
2345 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2347 /* Switch state to ESTABLISHED */
2348 tc0->state = TCP_STATE_ESTABLISHED;
2350 /* Initialize session variables */
2351 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2352 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2353 << tc0->rcv_opts.wscale;
2354 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2355 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2356 stream_session_accept_notify (&tc0->connection);
2358 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2359 tcp_retransmit_timer_reset (tc0);
2360 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2361 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2363 case TCP_STATE_ESTABLISHED:
2364 /* We can get packets in established state here because they
2365 * were enqueued before state change */
2366 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2370 case TCP_STATE_FIN_WAIT_1:
2371 /* In addition to the processing for the ESTABLISHED state, if
2372 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2373 * continue processing in that state. */
2374 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2377 /* Still have to send the FIN */
2378 if (tc0->flags & TCP_CONN_FINPNDG)
2380 /* TX fifo finally drained */
2381 if (!stream_session_tx_fifo_max_dequeue (&tc0->connection))
2384 /* If FIN is ACKed */
2385 else if (tc0->snd_una == tc0->snd_una_max)
2388 tc0->state = TCP_STATE_FIN_WAIT_2;
2389 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2393 /* Stop all timers, 2MSL will be set lower */
2394 tcp_connection_timers_reset (tc0);
2398 /* Wait for peer to finish sending its data */
2399 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2404 case TCP_STATE_FIN_WAIT_2:
2405 /* In addition to the processing for the ESTABLISHED state, if
2406 * the retransmission queue is empty, the user's CLOSE can be
2407 * acknowledged ("ok") but do not delete the TCB. */
2408 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2411 case TCP_STATE_CLOSE_WAIT:
2412 /* Do the same processing as for the ESTABLISHED state. */
2413 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2416 case TCP_STATE_CLOSING:
2417 /* In addition to the processing for the ESTABLISHED state, if
2418 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2419 * otherwise ignore the segment. */
2420 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2423 tc0->state = TCP_STATE_TIME_WAIT;
2424 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2425 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2429 case TCP_STATE_LAST_ACK:
2430 /* The only thing that [should] arrive in this state is an
2431 * acknowledgment of our FIN. If our FIN is now acknowledged,
2432 * delete the TCB, enter the CLOSED state, and return. */
2434 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2437 /* Apparently our FIN was lost */
2440 /* Don't "make" fin since that increments snd_nxt */
2445 tc0->state = TCP_STATE_CLOSED;
2446 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2448 /* Don't delete the connection/session yet. Instead, wait a
2449 * reasonable amount of time until the pipes are cleared. In
2450 * particular, this makes sure that we won't have dead sessions
2451 * when processing events on the tx path */
2452 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2454 /* Stop retransmit */
2455 tcp_retransmit_timer_reset (tc0);
2460 case TCP_STATE_TIME_WAIT:
2461 /* The only thing that can arrive in this state is a
2462 * retransmission of the remote FIN. Acknowledge it, and restart
2463 * the 2 MSL timeout. */
2465 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2468 tcp_make_ack (tc0, b0);
2469 tcp_timer_reset (tc0, TCP_TIMER_WAITCLOSE);
2470 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2479 /* 6: check the URG bit TODO */
2481 /* 7: process the segment text */
2484 case TCP_STATE_ESTABLISHED:
2485 case TCP_STATE_FIN_WAIT_1:
2486 case TCP_STATE_FIN_WAIT_2:
2487 if (vnet_buffer (b0)->tcp.data_len)
2488 error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
2490 case TCP_STATE_CLOSE_WAIT:
2491 case TCP_STATE_CLOSING:
2492 case TCP_STATE_LAST_ACK:
2493 case TCP_STATE_TIME_WAIT:
2494 /* This should not occur, since a FIN has been received from the
2495 * remote side. Ignore the segment text. */
2499 /* 8: check the FIN bit */
2500 if (!tcp_fin (tcp0))
2505 case TCP_STATE_ESTABLISHED:
2506 case TCP_STATE_SYN_RCVD:
2507 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2508 tcp_connection_timers_reset (tc0);
2509 tcp_make_fin (tc0, b0);
2511 next0 = tcp_next_output (tc0->c_is_ip4);
2512 stream_session_disconnect_notify (&tc0->connection);
2513 tc0->state = TCP_STATE_CLOSE_WAIT;
2514 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2516 case TCP_STATE_CLOSE_WAIT:
2517 case TCP_STATE_CLOSING:
2518 case TCP_STATE_LAST_ACK:
2521 case TCP_STATE_FIN_WAIT_1:
2522 tc0->state = TCP_STATE_CLOSING;
2523 tcp_make_ack (tc0, b0);
2524 next0 = tcp_next_output (is_ip4);
2525 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2526 /* Wait for ACK but not forever */
2527 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2529 case TCP_STATE_FIN_WAIT_2:
2530 /* Got FIN, send ACK! */
2531 tc0->state = TCP_STATE_TIME_WAIT;
2532 tcp_connection_timers_reset (tc0);
2533 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2534 tcp_make_ack (tc0, b0);
2535 next0 = tcp_next_output (is_ip4);
2536 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2538 case TCP_STATE_TIME_WAIT:
2539 /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
2542 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2545 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2548 b0->error = error0 ? node->errors[error0] : 0;
2550 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2552 tcp_rx_trace_t *t0 =
2553 vlib_add_trace (vm, node, b0, sizeof (*t0));
2554 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2557 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2558 n_left_to_next, bi0, next0);
2561 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2564 errors = session_manager_flush_enqueue_events (my_thread_index);
2568 vlib_node_increment_counter (vm, tcp4_established_node.index,
2569 TCP_ERROR_EVENT_FIFO_FULL, errors);
2571 vlib_node_increment_counter (vm, tcp6_established_node.index,
2572 TCP_ERROR_EVENT_FIFO_FULL, errors);
2575 return from_frame->n_vectors;
2579 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2580 vlib_frame_t * from_frame)
2582 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2586 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2587 vlib_frame_t * from_frame)
2589 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2593 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2595 .function = tcp4_rcv_process,
2596 .name = "tcp4-rcv-process",
2597 /* Takes a vector of packets. */
2598 .vector_size = sizeof (u32),
2599 .n_errors = TCP_N_ERROR,
2600 .error_strings = tcp_error_strings,
2601 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2604 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2605 foreach_tcp_state_next
2608 .format_trace = format_tcp_rx_trace_short,
2612 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2615 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2617 .function = tcp6_rcv_process,
2618 .name = "tcp6-rcv-process",
2619 /* Takes a vector of packets. */
2620 .vector_size = sizeof (u32),
2621 .n_errors = TCP_N_ERROR,
2622 .error_strings = tcp_error_strings,
2623 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2626 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2627 foreach_tcp_state_next
2630 .format_trace = format_tcp_rx_trace_short,
2634 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2636 vlib_node_registration_t tcp4_listen_node;
2637 vlib_node_registration_t tcp6_listen_node;
2640 * LISTEN state processing as per RFC 793 p. 65
2643 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2644 vlib_frame_t * from_frame, int is_ip4)
2646 u32 n_left_from, next_index, *from, *to_next;
2647 u32 my_thread_index = vm->thread_index;
2648 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
2650 from = vlib_frame_vector_args (from_frame);
2651 n_left_from = from_frame->n_vectors;
2653 next_index = node->cached_next_index;
2655 while (n_left_from > 0)
2659 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2661 while (n_left_from > 0 && n_left_to_next > 0)
2666 tcp_header_t *th0 = 0;
2667 tcp_connection_t *lc0;
2670 tcp_connection_t *child0;
2671 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2678 n_left_to_next -= 1;
2680 b0 = vlib_get_buffer (vm, bi0);
2681 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2685 ip40 = vlib_buffer_get_current (b0);
2686 th0 = ip4_next_header (ip40);
2690 ip60 = vlib_buffer_get_current (b0);
2691 th0 = ip6_next_header (ip60);
2694 /* Create child session. For syn-flood protection use filter */
2696 /* 1. first check for an RST: handled in dispatch */
2697 /* if (tcp_rst (th0))
2700 /* 2. second check for an ACK: handled in dispatch */
2701 /* if (tcp_ack (th0))
2703 tcp_send_reset (b0, is_ip4);
2707 /* 3. check for a SYN (did that already) */
2709 /* Make sure connection wasn't just created */
2710 child0 = tcp_lookup_connection (b0, my_thread_index, is_ip4);
2711 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
2713 error0 = TCP_ERROR_CREATE_EXISTS;
2717 /* Create child session and send SYN-ACK */
2718 child0 = tcp_connection_new (my_thread_index);
2719 child0->c_lcl_port = lc0->c_lcl_port;
2720 child0->c_rmt_port = th0->src_port;
2721 child0->c_is_ip4 = is_ip4;
2722 child0->state = TCP_STATE_SYN_RCVD;
2726 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2727 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2731 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2732 sizeof (ip6_address_t));
2733 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2734 sizeof (ip6_address_t));
2737 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2740 clib_warning ("session accept fail");
2741 tcp_connection_cleanup (child0);
2742 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2746 if (tcp_options_parse (th0, &child0->rcv_opts))
2748 clib_warning ("options parse fail");
2752 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2753 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2754 child0->rcv_las = child0->rcv_nxt;
2756 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2757 * segments are used to initialize PAWS. */
2758 if (tcp_opts_tstamp (&child0->rcv_opts))
2760 child0->tsval_recent = child0->rcv_opts.tsval;
2761 child0->tsval_recent_age = tcp_time_now ();
2764 if (tcp_opts_wscale (&child0->rcv_opts))
2765 child0->snd_wscale = child0->rcv_opts.wscale;
2767 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2768 << child0->snd_wscale;
2769 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2770 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2772 tcp_connection_init_vars (child0);
2773 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
2775 /* Reuse buffer to make syn-ack and send */
2776 tcp_make_synack (child0, b0);
2777 next0 = tcp_next_output (is_ip4);
2778 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
2781 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2783 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2784 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2785 clib_memcpy (&t0->tcp_connection, lc0,
2786 sizeof (t0->tcp_connection));
2789 b0->error = node->errors[error0];
2791 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2792 n_left_to_next, bi0, next0);
2795 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2797 return from_frame->n_vectors;
2801 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2802 vlib_frame_t * from_frame)
2804 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2808 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2809 vlib_frame_t * from_frame)
2811 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2815 VLIB_REGISTER_NODE (tcp4_listen_node) =
2817 .function = tcp4_listen,
2818 .name = "tcp4-listen",
2819 /* Takes a vector of packets. */
2820 .vector_size = sizeof (u32),
2821 .n_errors = TCP_N_ERROR,
2822 .error_strings = tcp_error_strings,
2823 .n_next_nodes = TCP_LISTEN_N_NEXT,
2826 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2827 foreach_tcp_state_next
2830 .format_trace = format_tcp_rx_trace_short,
2834 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2837 VLIB_REGISTER_NODE (tcp6_listen_node) =
2839 .function = tcp6_listen,
2840 .name = "tcp6-listen",
2841 /* Takes a vector of packets. */
2842 .vector_size = sizeof (u32),
2843 .n_errors = TCP_N_ERROR,
2844 .error_strings = tcp_error_strings,
2845 .n_next_nodes = TCP_LISTEN_N_NEXT,
2848 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2849 foreach_tcp_state_next
2852 .format_trace = format_tcp_rx_trace_short,
2856 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2858 vlib_node_registration_t tcp4_input_node;
2859 vlib_node_registration_t tcp6_input_node;
2861 typedef enum _tcp_input_next
2863 TCP_INPUT_NEXT_DROP,
2864 TCP_INPUT_NEXT_LISTEN,
2865 TCP_INPUT_NEXT_RCV_PROCESS,
2866 TCP_INPUT_NEXT_SYN_SENT,
2867 TCP_INPUT_NEXT_ESTABLISHED,
2868 TCP_INPUT_NEXT_RESET,
2872 #define foreach_tcp4_input_next \
2873 _ (DROP, "error-drop") \
2874 _ (LISTEN, "tcp4-listen") \
2875 _ (RCV_PROCESS, "tcp4-rcv-process") \
2876 _ (SYN_SENT, "tcp4-syn-sent") \
2877 _ (ESTABLISHED, "tcp4-established") \
2878 _ (RESET, "tcp4-reset")
2880 #define foreach_tcp6_input_next \
2881 _ (DROP, "error-drop") \
2882 _ (LISTEN, "tcp6-listen") \
2883 _ (RCV_PROCESS, "tcp6-rcv-process") \
2884 _ (SYN_SENT, "tcp6-syn-sent") \
2885 _ (ESTABLISHED, "tcp6-established") \
2886 _ (RESET, "tcp6-reset")
2888 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2891 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2892 vlib_frame_t * from_frame, int is_ip4)
2894 u32 n_left_from, next_index, *from, *to_next;
2895 u32 my_thread_index = vm->thread_index;
2896 tcp_main_t *tm = vnet_get_tcp_main ();
2898 from = vlib_frame_vector_args (from_frame);
2899 n_left_from = from_frame->n_vectors;
2900 next_index = node->cached_next_index;
2901 tcp_set_time_now (my_thread_index);
2903 while (n_left_from > 0)
2907 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2909 while (n_left_from > 0 && n_left_to_next > 0)
2911 int n_advance_bytes0, n_data_bytes0;
2914 tcp_header_t *tcp0 = 0;
2915 tcp_connection_t *tc0;
2916 transport_connection_t *tconn;
2919 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2927 n_left_to_next -= 1;
2929 b0 = vlib_get_buffer (vm, bi0);
2930 vnet_buffer (b0)->tcp.flags = 0;
2932 /* Checksum computed by ipx_local no need to compute again */
2936 ip40 = vlib_buffer_get_current (b0);
2937 tcp0 = ip4_next_header (ip40);
2938 n_advance_bytes0 = (ip4_header_bytes (ip40)
2939 + tcp_header_bytes (tcp0));
2940 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2942 tconn = stream_session_lookup_transport_wt4 (&ip40->dst_address,
2946 SESSION_TYPE_IP4_TCP,
2948 tc0 = tcp_get_connection_from_transport (tconn);
2949 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
2953 ip60 = vlib_buffer_get_current (b0);
2954 tcp0 = ip6_next_header (ip60);
2955 n_advance_bytes0 = tcp_header_bytes (tcp0);
2956 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2958 n_advance_bytes0 += sizeof (ip60[0]);
2959 tconn = stream_session_lookup_transport_wt6 (&ip60->dst_address,
2963 SESSION_TYPE_IP6_TCP,
2965 tc0 = tcp_get_connection_from_transport (tconn);
2966 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
2970 if (PREDICT_FALSE (n_advance_bytes0 < 0))
2972 error0 = TCP_ERROR_LENGTH;
2976 /* Session exists */
2977 if (PREDICT_TRUE (0 != tc0))
2979 /* Save connection index */
2980 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2981 vnet_buffer (b0)->tcp.seq_number =
2982 clib_net_to_host_u32 (tcp0->seq_number);
2983 vnet_buffer (b0)->tcp.ack_number =
2984 clib_net_to_host_u32 (tcp0->ack_number);
2986 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
2987 - (u8 *) vlib_buffer_get_current (b0);
2988 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
2989 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
2991 flags0 = tcp0->flags & filter_flags;
2992 next0 = tm->dispatch_table[tc0->state][flags0].next;
2993 error0 = tm->dispatch_table[tc0->state][flags0].error;
2995 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH
2996 || next0 == TCP_INPUT_NEXT_RESET))
2998 /* Overload tcp flags to store state */
2999 tcp_state_t state0 = tc0->state;
3000 vnet_buffer (b0)->tcp.flags = tc0->state;
3002 if (error0 == TCP_ERROR_DISPATCH)
3003 clib_warning ("disp error state %U flags %U",
3004 format_tcp_state, state0, format_tcp_flags,
3011 next0 = TCP_INPUT_NEXT_RESET;
3012 error0 = TCP_ERROR_NO_LISTENER;
3016 b0->error = error0 ? node->errors[error0] : 0;
3018 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3020 tcp_rx_trace_t *t0 =
3021 vlib_add_trace (vm, node, b0, sizeof (*t0));
3022 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3024 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
3025 n_left_to_next, bi0, next0);
3028 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3031 return from_frame->n_vectors;
3035 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3036 vlib_frame_t * from_frame)
3038 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3042 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3043 vlib_frame_t * from_frame)
3045 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3049 VLIB_REGISTER_NODE (tcp4_input_node) =
3051 .function = tcp4_input,
3052 .name = "tcp4-input",
3053 /* Takes a vector of packets. */
3054 .vector_size = sizeof (u32),
3055 .n_errors = TCP_N_ERROR,
3056 .error_strings = tcp_error_strings,
3057 .n_next_nodes = TCP_INPUT_N_NEXT,
3060 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3061 foreach_tcp4_input_next
3064 .format_buffer = format_tcp_header,
3065 .format_trace = format_tcp_rx_trace,
3069 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3072 VLIB_REGISTER_NODE (tcp6_input_node) =
3074 .function = tcp6_input,
3075 .name = "tcp6-input",
3076 /* Takes a vector of packets. */
3077 .vector_size = sizeof (u32),
3078 .n_errors = TCP_N_ERROR,
3079 .error_strings = tcp_error_strings,
3080 .n_next_nodes = TCP_INPUT_N_NEXT,
3083 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3084 foreach_tcp6_input_next
3087 .format_buffer = format_tcp_header,
3088 .format_trace = format_tcp_rx_trace,
3092 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3095 tcp_dispatch_table_init (tcp_main_t * tm)
3098 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3099 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3101 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3102 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3105 #define _(t,f,n,e) \
3107 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3108 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3111 /* SYNs for new connections -> tcp-listen. */
3112 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3113 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3114 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_NONE);
3115 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3117 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3118 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3119 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3120 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3121 /* SYN-ACK for a SYN */
3122 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3124 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3125 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3126 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3128 /* ACK for for established connection -> tcp-established. */
3129 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3130 /* FIN for for established connection -> tcp-established. */
3131 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3132 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3134 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3135 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3137 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3138 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3140 /* ACK or FIN-ACK to our FIN */
3141 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3142 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3144 /* FIN in reply to our FIN from the other side */
3145 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3146 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3147 /* FIN confirming that the peer (app) has closed */
3148 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3149 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3150 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3152 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3153 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3155 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3156 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3157 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3159 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3160 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3161 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3163 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3164 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3165 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_CONNECTION_CLOSED);
3166 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3167 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3168 TCP_ERROR_CONNECTION_CLOSED);
3173 tcp_input_init (vlib_main_t * vm)
3175 clib_error_t *error = 0;
3176 tcp_main_t *tm = vnet_get_tcp_main ();
3178 if ((error = vlib_call_init_function (vm, tcp_init)))
3181 /* Initialize dispatch table. */
3182 tcp_dispatch_table_init (tm);
3187 VLIB_INIT_FUNCTION (tcp_input_init);
3190 * fd.io coding-style-patch-verification: ON
3193 * eval: (c-set-style "gnu")