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) && seq_leq (seq, tc->rcv_las)
252 && 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);
422 * Update RTT estimate and RTO timer
424 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
425 * timing. Middle boxes are known to fiddle with TCP options so we
426 * should give higher priority to ACK timing.
428 * This should be called only if previously sent bytes have been acked.
430 * return 1 if valid rtt 0 otherwise
433 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
437 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
438 * RTT because they're ambiguous. */
439 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
442 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
444 mrtt = tcp_time_now () - tc->rtt_ts;
446 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
447 * snd_una, i.e., the left side of the send window:
448 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
449 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
451 mrtt = tcp_time_now () - tc->rcv_opts.tsecr;
454 /* Ignore dubious measurements */
455 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
458 tcp_estimate_rtt (tc, mrtt);
462 /* Allow measuring of a new RTT */
465 /* If we got here something must've been ACKed so make sure boff is 0,
466 * even if mrrt is not valid since we update the rto lower */
474 * Dequeue bytes that have been acked and while at it update RTT estimates.
477 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
479 /* Dequeue the newly ACKed add SACKed bytes */
480 stream_session_dequeue_drop (&tc->connection,
481 tc->bytes_acked + tc->sack_sb.snd_una_adv);
483 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
485 /* Update rtt and rto */
486 tcp_update_rtt (tc, ack);
488 /* If everything has been acked, stop retransmit timer
489 * otherwise update. */
490 tcp_retransmit_timer_update (tc);
494 * Check if duplicate ack as per RFC5681 Sec. 2
497 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
500 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
501 && seq_gt (tc->snd_una_max, tc->snd_una)
502 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
503 && (prev_snd_wnd == tc->snd_wnd));
507 * Checks if ack is a congestion control event.
510 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
511 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
513 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
514 * defined to be 'duplicate' */
515 *is_dack = tc->sack_sb.last_sacked_bytes
516 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
518 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
522 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
524 sack_scoreboard_hole_t *next, *prev;
526 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
528 next = pool_elt_at_index (sb->holes, hole->next);
529 next->prev = hole->prev;
533 sb->tail = hole->prev;
536 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
538 prev = pool_elt_at_index (sb->holes, hole->prev);
539 prev->next = hole->next;
543 sb->head = hole->next;
546 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
547 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
549 /* Poison the entry */
551 memset (hole, 0xfe, sizeof (*hole));
553 pool_put (sb->holes, hole);
556 sack_scoreboard_hole_t *
557 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
560 sack_scoreboard_hole_t *hole, *next, *prev;
563 pool_get (sb->holes, hole);
564 memset (hole, 0, sizeof (*hole));
568 hole_index = scoreboard_hole_index (sb, hole);
570 prev = scoreboard_get_hole (sb, prev_index);
573 hole->prev = prev_index;
574 hole->next = prev->next;
576 if ((next = scoreboard_next_hole (sb, hole)))
577 next->prev = hole_index;
579 sb->tail = hole_index;
581 prev->next = hole_index;
585 sb->head = hole_index;
586 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
587 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
594 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
596 sack_scoreboard_hole_t *hole, *prev;
597 u32 bytes = 0, blks = 0;
600 sb->sacked_bytes = 0;
601 hole = scoreboard_last_hole (sb);
605 if (seq_gt (sb->high_sacked, hole->end))
607 bytes = sb->high_sacked - hole->end;
611 while ((prev = scoreboard_prev_hole (sb, hole))
612 && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
613 && blks < TCP_DUPACK_THRESHOLD))
615 bytes += hole->start - prev->end;
622 sb->lost_bytes += scoreboard_hole_bytes (hole);
625 hole = scoreboard_prev_hole (sb, hole);
627 bytes += prev->start - hole->end;
629 sb->sacked_bytes = bytes;
633 * Figure out the next hole to retransmit
635 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
637 sack_scoreboard_hole_t *
638 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
639 sack_scoreboard_hole_t * start,
641 u8 * can_rescue, u8 * snd_limited)
643 sack_scoreboard_hole_t *hole = 0;
645 hole = start ? start : scoreboard_first_hole (sb);
646 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
647 hole = scoreboard_next_hole (sb, hole);
649 /* Nothing, return */
652 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
656 /* Rule (1): if higher than rxt, less than high_sacked and lost */
657 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
659 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
663 /* Rule (2): output takes care of transmitting new data */
664 if (!have_sent_1_smss)
667 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
669 /* Rule (3): if hole not lost */
670 else if (seq_lt (hole->start, sb->high_sacked))
673 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
675 /* Rule (4): if hole beyond high_sacked */
678 ASSERT (seq_geq (hole->start, sb->high_sacked));
681 /* HighRxt MUST NOT be updated */
686 if (hole && seq_lt (sb->high_rxt, hole->start))
687 sb->high_rxt = hole->start;
693 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
695 sack_scoreboard_hole_t *hole;
696 hole = scoreboard_first_hole (sb);
699 seq = seq_gt (seq, hole->start) ? seq : hole->start;
700 sb->cur_rxt_hole = sb->head;
706 * Test that scoreboard is sane after recovery
708 * Returns 1 if scoreboard is empty or if first hole beyond
712 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
714 sack_scoreboard_hole_t *hole;
715 hole = scoreboard_first_hole (&tc->sack_sb);
716 return (!hole || seq_geq (hole->start, tc->snd_una));
720 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
722 sack_scoreboard_t *sb = &tc->sack_sb;
723 sack_block_t *blk, tmp;
724 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
725 u32 blk_index = 0, old_sacked_bytes, hole_index;
728 sb->last_sacked_bytes = 0;
730 old_sacked_bytes = sb->sacked_bytes;
731 sb->last_bytes_delivered = 0;
733 if (!tcp_opts_sack (&tc->rcv_opts)
734 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
737 /* Remove invalid blocks */
738 blk = tc->rcv_opts.sacks;
739 while (blk < vec_end (tc->rcv_opts.sacks))
741 if (seq_lt (blk->start, blk->end)
742 && seq_gt (blk->start, tc->snd_una)
743 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
748 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
751 /* Add block for cumulative ack */
752 if (seq_gt (ack, tc->snd_una))
754 tmp.start = tc->snd_una;
756 vec_add1 (tc->rcv_opts.sacks, tmp);
759 if (vec_len (tc->rcv_opts.sacks) == 0)
762 tcp_scoreboard_trace_add (tc, ack);
764 /* Make sure blocks are ordered */
765 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
766 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
767 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
769 tmp = tc->rcv_opts.sacks[i];
770 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
771 tc->rcv_opts.sacks[j] = tmp;
774 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
776 /* If no holes, insert the first that covers all outstanding bytes */
777 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
778 tc->snd_una, tc->snd_una_max);
779 sb->tail = scoreboard_hole_index (sb, last_hole);
780 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
781 sb->high_sacked = tmp.end;
785 /* If we have holes but snd_una_max is beyond the last hole, update
787 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
788 last_hole = scoreboard_last_hole (sb);
789 if (seq_gt (tc->snd_una_max, last_hole->end))
791 if (seq_geq (last_hole->start, sb->high_sacked))
793 last_hole->end = tc->snd_una_max;
795 /* New hole after high sacked block */
796 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
798 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
802 /* Keep track of max byte sacked for when the last hole
804 if (seq_gt (tmp.end, sb->high_sacked))
805 sb->high_sacked = tmp.end;
808 /* Walk the holes with the SACK blocks */
809 hole = pool_elt_at_index (sb->holes, sb->head);
810 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
812 blk = &tc->rcv_opts.sacks[blk_index];
813 if (seq_leq (blk->start, hole->start))
815 /* Block covers hole. Remove hole */
816 if (seq_geq (blk->end, hole->end))
818 next_hole = scoreboard_next_hole (sb, hole);
820 /* Byte accounting: snd_una needs to be advanced */
825 if (seq_lt (ack, next_hole->start))
826 sb->snd_una_adv = next_hole->start - ack;
827 sb->last_bytes_delivered +=
828 next_hole->start - hole->end;
832 ASSERT (seq_geq (sb->high_sacked, ack));
833 sb->snd_una_adv = sb->high_sacked - ack;
834 sb->last_bytes_delivered += sb->high_sacked - hole->end;
838 scoreboard_remove_hole (sb, hole);
841 /* Partial 'head' overlap */
844 if (seq_gt (blk->end, hole->start))
846 hole->start = blk->end;
853 /* Hole must be split */
854 if (seq_lt (blk->end, hole->end))
856 hole_index = scoreboard_hole_index (sb, hole);
857 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
860 /* Pool might've moved */
861 hole = scoreboard_get_hole (sb, hole_index);
862 hole->end = blk->start;
864 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
866 else if (seq_lt (blk->start, hole->end))
868 hole->end = blk->start;
870 hole = scoreboard_next_hole (sb, hole);
874 scoreboard_update_bytes (tc, sb);
875 sb->last_sacked_bytes = sb->sacked_bytes
876 - (old_sacked_bytes - sb->last_bytes_delivered);
877 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes);
878 ASSERT (sb->sacked_bytes == 0
879 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
880 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
881 - seq_max (tc->snd_una, ack));
882 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
883 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
887 * Try to update snd_wnd based on feedback received from peer.
889 * If successful, and new window is 'effectively' 0, activate persist
893 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
895 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
896 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
897 if (seq_lt (tc->snd_wl1, seq)
898 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
900 tc->snd_wnd = snd_wnd;
903 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
905 if (tc->snd_wnd < tc->snd_mss)
907 /* Set persist timer if not set and we just got 0 wnd */
908 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
909 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
910 tcp_persist_timer_set (tc);
914 tcp_persist_timer_reset (tc);
915 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
925 tcp_cc_init_congestion (tcp_connection_t * tc)
927 tcp_fastrecovery_on (tc);
928 tc->snd_congestion = tc->snd_una_max;
929 tc->cc_algo->congestion (tc);
930 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
934 tcp_cc_recovery_exit (tcp_connection_t * tc)
940 tc->snd_nxt = tc->snd_una_max;
941 tcp_recovery_off (tc);
942 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
946 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
948 tc->cc_algo->recovered (tc);
949 tc->snd_rxt_bytes = 0;
951 tc->snd_nxt = tc->snd_una_max;
952 tcp_fastrecovery_off (tc);
953 tcp_fastrecovery_1_smss_off (tc);
954 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
958 tcp_cc_congestion_undo (tcp_connection_t * tc)
960 tc->cwnd = tc->prev_cwnd;
961 tc->ssthresh = tc->prev_ssthresh;
962 tc->snd_nxt = tc->snd_una_max;
964 if (tcp_in_recovery (tc))
965 tcp_cc_recovery_exit (tc);
966 ASSERT (tc->rto_boff == 0);
967 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
968 /* TODO extend for fastrecovery */
972 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
974 return (tcp_in_recovery (tc) && tc->rto_boff == 1
976 && tcp_opts_tstamp (&tc->rcv_opts)
977 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
981 tcp_cc_recover (tcp_connection_t * tc)
983 ASSERT (tcp_in_cong_recovery (tc));
984 if (tcp_cc_is_spurious_retransmit (tc))
986 tcp_cc_congestion_undo (tc);
990 if (tcp_in_recovery (tc))
991 tcp_cc_recovery_exit (tc);
992 else if (tcp_in_fastrecovery (tc))
993 tcp_cc_fastrecovery_exit (tc);
995 ASSERT (tc->rto_boff == 0);
996 ASSERT (!tcp_in_cong_recovery (tc));
997 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1002 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1004 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1006 /* Congestion avoidance */
1007 tc->cc_algo->rcv_ack (tc);
1008 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1010 /* If a cumulative ack, make sure dupacks is 0 */
1011 tc->rcv_dupacks = 0;
1013 /* When dupacks hits the threshold we only enter fast retransmit if
1014 * cumulative ack covers more than snd_congestion. Should snd_una
1015 * wrap this test may fail under otherwise valid circumstances.
1016 * Therefore, proactively update snd_congestion when wrap detected. */
1018 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1019 && seq_gt (tc->snd_congestion, tc->snd_una)))
1020 tc->snd_congestion = tc->snd_una - 1;
1024 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1026 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1030 tcp_should_fastrecover (tcp_connection_t * tc)
1032 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1033 || tcp_should_fastrecover_sack (tc));
1037 * One function to rule them all ... and in the darkness bind them
1040 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1045 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1046 * it account for the bytes that left the network.
1050 ASSERT (tc->snd_una != tc->snd_una_max
1051 || tc->sack_sb.last_sacked_bytes);
1055 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1057 ASSERT (tcp_in_fastrecovery (tc));
1058 /* Pure duplicate ack. If some data got acked, it's handled lower */
1059 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1062 else if (tcp_should_fastrecover (tc))
1064 /* Things are already bad */
1065 if (tcp_in_cong_recovery (tc))
1067 tc->rcv_dupacks = 0;
1068 goto partial_ack_test;
1071 /* If of of the two conditions lower hold, reset dupacks because
1072 * we're probably after timeout (RFC6582 heuristics).
1073 * If Cumulative ack does not cover more than congestion threshold,
1075 * 1) The following doesn't hold: The congestion window is greater
1076 * than SMSS bytes and the difference between highest_ack
1077 * and prev_highest_ack is at most 4*SMSS bytes
1078 * 2) Echoed timestamp in the last non-dup ack does not equal the
1081 if (seq_leq (tc->snd_una, tc->snd_congestion)
1082 && ((!(tc->cwnd > tc->snd_mss
1083 && tc->bytes_acked <= 4 * tc->snd_mss))
1084 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1086 tc->rcv_dupacks = 0;
1090 tcp_cc_init_congestion (tc);
1091 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1093 /* The first segment MUST be retransmitted */
1094 tcp_retransmit_first_unacked (tc);
1096 /* Post retransmit update cwnd to ssthresh and account for the
1097 * three segments that have left the network and should've been
1098 * buffered at the receiver XXX */
1099 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1100 ASSERT (tc->cwnd >= tc->snd_mss);
1102 /* If cwnd allows, send more data */
1103 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1105 scoreboard_init_high_rxt (&tc->sack_sb,
1106 tc->snd_una + tc->snd_mss);
1107 tcp_fast_retransmit_sack (tc);
1111 tcp_fast_retransmit_no_sack (tc);
1116 else if (!tc->bytes_acked
1117 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1119 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1128 if (!tc->bytes_acked)
1133 * Legitimate ACK. 1) See if we can exit recovery
1135 /* XXX limit this only to first partial ack? */
1136 tcp_retransmit_timer_update (tc);
1138 if (seq_geq (tc->snd_una, tc->snd_congestion))
1140 /* If spurious return, we've already updated everything */
1141 if (tcp_cc_recover (tc))
1143 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1147 tc->snd_nxt = tc->snd_una_max;
1149 /* Treat as congestion avoidance ack */
1150 tc->cc_algo->rcv_ack (tc);
1151 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1156 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1158 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1160 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1161 * reset dupacks to 0 */
1162 tc->rcv_dupacks = 0;
1164 tcp_retransmit_first_unacked (tc);
1166 /* Post RTO timeout don't try anything fancy */
1167 if (tcp_in_recovery (tc))
1170 /* Remove retransmitted bytes that have been delivered */
1171 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1172 >= tc->sack_sb.last_bytes_delivered
1173 || (tc->flags & TCP_CONN_FINSNT));
1175 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1177 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1178 * remove sacked bytes delivered */
1179 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1180 - tc->sack_sb.last_bytes_delivered;
1181 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1182 tc->snd_rxt_bytes -= rxt_delivered;
1186 /* Either all retransmitted holes have been acked, or we're
1187 * "in the blind" and retransmitting segment by segment */
1188 tc->snd_rxt_bytes = 0;
1191 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1194 * Since this was a partial ack, try to retransmit some more data
1196 tcp_fast_retransmit (tc);
1200 tcp_cc_init (tcp_connection_t * tc)
1202 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
1203 tc->cc_algo->init (tc);
1207 * Process incoming ACK
1210 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1211 tcp_header_t * th, u32 * next, u32 * error)
1213 u32 prev_snd_wnd, prev_snd_una;
1216 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1218 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1219 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1221 /* If we have outstanding data and this is within the window, accept it,
1222 * probably retransmit has timed out. Otherwise ACK segment and then
1224 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1226 tcp_make_ack (tc, b);
1227 *next = tcp_next_output (tc->c_is_ip4);
1228 *error = TCP_ERROR_ACK_INVALID;
1229 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1230 vnet_buffer (b)->tcp.ack_number);
1234 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1235 vnet_buffer (b)->tcp.ack_number);
1237 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1238 *error = TCP_ERROR_ACK_FUTURE;
1241 /* If old ACK, probably it's an old dupack */
1242 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1244 *error = TCP_ERROR_ACK_OLD;
1245 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1246 vnet_buffer (b)->tcp.ack_number);
1247 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1249 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
1250 tcp_cc_handle_event (tc, 1);
1252 /* Don't drop yet */
1257 * Looks okay, process feedback
1260 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1261 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1263 prev_snd_wnd = tc->snd_wnd;
1264 prev_snd_una = tc->snd_una;
1265 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1266 vnet_buffer (b)->tcp.ack_number,
1267 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1268 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1269 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1270 tcp_validate_txf_size (tc, tc->bytes_acked);
1272 if (tc->bytes_acked)
1273 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1275 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1278 * Check if we have congestion event
1281 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1283 tcp_cc_handle_event (tc, is_dack);
1284 if (!tcp_in_cong_recovery (tc))
1286 *error = TCP_ERROR_ACK_DUP;
1287 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1288 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1292 * Update congestion control (slow start/congestion avoidance)
1294 tcp_cc_update (tc, b);
1300 tcp_sack_vector_is_sane (sack_block_t * sacks)
1303 for (i = 1; i < vec_len (sacks); i++)
1305 if (sacks[i - 1].end == sacks[i].start)
1312 * Build SACK list as per RFC2018.
1314 * Makes sure the first block contains the segment that generated the current
1315 * ACK and the following ones are the ones most recently reported in SACK
1318 * @param tc TCP connection for which the SACK list is updated
1319 * @param start Start sequence number of the newest SACK block
1320 * @param end End sequence of the newest SACK block
1323 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1325 sack_block_t *new_list = 0, *block = 0;
1328 /* If the first segment is ooo add it to the list. Last write might've moved
1329 * rcv_nxt over the first segment. */
1330 if (seq_lt (tc->rcv_nxt, start))
1332 vec_add2 (new_list, block, 1);
1333 block->start = start;
1337 /* Find the blocks still worth keeping. */
1338 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1340 /* Discard if rcv_nxt advanced beyond current block */
1341 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1344 /* Merge or drop if segment overlapped by the new segment */
1345 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1346 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1348 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1349 new_list[0].start = tc->snd_sacks[i].start;
1350 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1351 new_list[0].end = tc->snd_sacks[i].end;
1355 /* Save to new SACK list if we have space. */
1356 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1358 vec_add1 (new_list, tc->snd_sacks[i]);
1362 clib_warning ("sack discarded");
1366 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1368 /* Replace old vector with new one */
1369 vec_free (tc->snd_sacks);
1370 tc->snd_sacks = new_list;
1372 /* Segments should not 'touch' */
1373 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1376 /** Enqueue data for delivery to application */
1378 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1381 int written, error = TCP_ERROR_ENQUEUED;
1383 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1385 /* Pure ACK. Update rcv_nxt and be done. */
1386 if (PREDICT_FALSE (data_len == 0))
1388 return TCP_ERROR_PURE_ACK;
1391 written = stream_session_enqueue_data (&tc->connection, b, 0,
1392 1 /* queue event */ , 1);
1394 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1396 /* Update rcv_nxt */
1397 if (PREDICT_TRUE (written == data_len))
1399 tc->rcv_nxt += written;
1401 /* If more data written than expected, account for out-of-order bytes. */
1402 else if (written > data_len)
1404 tc->rcv_nxt += written;
1406 /* Send ACK confirming the update */
1407 tc->flags |= TCP_CONN_SNDACK;
1409 else if (written > 0)
1411 /* We've written something but FIFO is probably full now */
1412 tc->rcv_nxt += written;
1414 /* Depending on how fast the app is, all remaining buffers in burst will
1415 * not be enqueued. Inform peer */
1416 tc->flags |= TCP_CONN_SNDACK;
1418 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1422 tc->flags |= TCP_CONN_SNDACK;
1423 return TCP_ERROR_FIFO_FULL;
1426 /* Update SACK list if need be */
1427 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1429 /* Remove SACK blocks that have been delivered */
1430 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1436 /** Enqueue out-of-order data */
1438 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1441 stream_session_t *s0;
1444 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1446 /* Pure ACK. Do nothing */
1447 if (PREDICT_FALSE (data_len == 0))
1449 return TCP_ERROR_PURE_ACK;
1452 /* Enqueue out-of-order data with relative offset */
1453 rv = stream_session_enqueue_data (&tc->connection, b,
1454 vnet_buffer (b)->tcp.seq_number -
1455 tc->rcv_nxt, 0 /* queue event */ , 0);
1457 /* Nothing written */
1460 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1461 return TCP_ERROR_FIFO_FULL;
1464 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1466 /* Update SACK list if in use */
1467 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1469 ooo_segment_t *newest;
1472 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1474 /* Get the newest segment from the fifo */
1475 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1478 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1479 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1480 start = tc->rcv_nxt + offset;
1481 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1482 tcp_update_sack_list (tc, start, end);
1483 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1487 return TCP_ERROR_ENQUEUED;
1491 * Check if ACK could be delayed. If ack can be delayed, it should return
1492 * true for a full frame. If we're always acking return 0.
1495 tcp_can_delack (tcp_connection_t * tc)
1497 /* Send ack if ... */
1499 /* just sent a rcv wnd 0 */
1500 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1501 /* constrained to send ack */
1502 || (tc->flags & TCP_CONN_SNDACK) != 0
1503 /* we're almost out of tx wnd */
1504 || tcp_available_snd_space (tc) < 4 * tc->snd_mss)
1511 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1513 u32 discard, first = b->current_length;
1514 vlib_main_t *vm = vlib_get_main ();
1516 /* Handle multi-buffer segments */
1517 if (n_bytes_to_drop > b->current_length)
1519 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1523 discard = clib_min (n_bytes_to_drop, b->current_length);
1524 vlib_buffer_advance (b, discard);
1525 b = vlib_get_buffer (vm, b->next_buffer);
1526 n_bytes_to_drop -= discard;
1528 while (n_bytes_to_drop);
1529 if (n_bytes_to_drop > first)
1530 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1533 vlib_buffer_advance (b, n_bytes_to_drop);
1534 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1539 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1542 u32 error = 0, n_bytes_to_drop, n_data_bytes;
1544 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1545 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1546 ASSERT (n_data_bytes);
1548 /* Handle out-of-order data */
1549 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1551 /* Old sequence numbers allowed through because they overlapped
1553 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1555 error = TCP_ERROR_SEGMENT_OLD;
1556 *next0 = TCP_NEXT_DROP;
1558 /* Completely in the past (possible retransmit) */
1559 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1561 /* Ack retransmissions since we may not have any data to send */
1562 tcp_make_ack (tc, b);
1563 *next0 = tcp_next_output (tc->c_is_ip4);
1567 /* Chop off the bytes in the past */
1568 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1569 n_data_bytes -= n_bytes_to_drop;
1570 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1571 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1577 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1579 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1580 * cwnd on remote peer when congested 2) acks leaving should have the
1581 * latest rcv_wnd since the burst may eaten up all of it, so only the
1582 * old ones could be filtered.
1585 /* RFC2581: Send DUPACK for fast retransmit */
1586 tcp_make_ack (tc, b);
1587 *next0 = tcp_next_output (tc->c_is_ip4);
1589 /* Mark as DUPACK. We may filter these in output if
1590 * the burst fills the holes. */
1592 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1594 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1600 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1601 * segments can be enqueued after fifo tail offset changes. */
1602 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1604 /* Check if ACK can be delayed */
1605 if (tcp_can_delack (tc))
1607 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1608 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1612 *next0 = tcp_next_output (tc->c_is_ip4);
1613 tcp_make_ack (tc, b);
1621 tcp_header_t tcp_header;
1622 tcp_connection_t tcp_connection;
1626 format_tcp_rx_trace (u8 * s, va_list * args)
1628 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1629 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1630 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1631 u32 indent = format_get_indent (s);
1633 s = format (s, "%U\n%U%U",
1634 format_tcp_header, &t->tcp_header, 128,
1635 format_white_space, indent,
1636 format_tcp_connection, &t->tcp_connection, 1);
1642 format_tcp_rx_trace_short (u8 * s, va_list * args)
1644 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1645 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1646 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1648 s = format (s, "%d -> %d (%U)",
1649 clib_net_to_host_u16 (t->tcp_header.src_port),
1650 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1651 t->tcp_connection.state);
1657 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1658 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1662 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1666 th0 = tcp_buffer_hdr (b0);
1668 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1672 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1674 if (PREDICT_TRUE (!val))
1678 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1680 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1684 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1685 vlib_frame_t * from_frame, int is_ip4)
1687 u32 n_left_from, next_index, *from, *to_next;
1688 u32 my_thread_index = vm->thread_index, errors = 0;
1689 tcp_main_t *tm = vnet_get_tcp_main ();
1692 from = vlib_frame_vector_args (from_frame);
1693 n_left_from = from_frame->n_vectors;
1695 next_index = node->cached_next_index;
1697 while (n_left_from > 0)
1701 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1702 while (n_left_from > 0 && n_left_to_next > 0)
1706 tcp_header_t *th0 = 0;
1707 tcp_connection_t *tc0;
1708 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1715 n_left_to_next -= 1;
1717 b0 = vlib_get_buffer (vm, bi0);
1718 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1721 if (PREDICT_FALSE (tc0 == 0))
1723 error0 = TCP_ERROR_INVALID_CONNECTION;
1727 th0 = tcp_buffer_hdr (b0);
1728 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1729 * dangling reference. */
1730 is_fin = tcp_is_fin (th0);
1732 /* SYNs, FINs and data consume sequence numbers */
1733 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1734 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1736 /* TODO header prediction fast path */
1738 /* 1-4: check SEQ, RST, SYN */
1739 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1741 error0 = TCP_ERROR_SEGMENT_INVALID;
1742 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1743 vnet_buffer (b0)->tcp.seq_number,
1744 vnet_buffer (b0)->tcp.seq_end);
1748 /* 5: check the ACK field */
1749 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1752 /* 6: check the URG bit TODO */
1754 /* 7: process the segment text */
1755 if (vnet_buffer (b0)->tcp.data_len)
1756 error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
1758 /* 8: check the FIN bit */
1759 if (PREDICT_FALSE (is_fin))
1761 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1762 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1763 /* Account for the FIN if nothing else was received */
1764 if (vnet_buffer (b0)->tcp.data_len == 0)
1766 tcp_make_ack (tc0, b0);
1767 next0 = tcp_next_output (tc0->c_is_ip4);
1768 tc0->state = TCP_STATE_CLOSE_WAIT;
1769 stream_session_disconnect_notify (&tc0->connection);
1770 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1771 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1775 b0->error = node->errors[error0];
1776 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1778 tcp_rx_trace_t *t0 =
1779 vlib_add_trace (vm, node, b0, sizeof (*t0));
1780 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1783 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1784 n_left_to_next, bi0, next0);
1787 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1790 errors = session_manager_flush_enqueue_events (my_thread_index);
1791 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1792 tcp_flush_frame_to_output (vm, my_thread_index, is_ip4);
1794 return from_frame->n_vectors;
1798 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1799 vlib_frame_t * from_frame)
1801 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1805 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1806 vlib_frame_t * from_frame)
1808 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1812 VLIB_REGISTER_NODE (tcp4_established_node) =
1814 .function = tcp4_established,
1815 .name = "tcp4-established",
1816 /* Takes a vector of packets. */
1817 .vector_size = sizeof (u32),
1818 .n_errors = TCP_N_ERROR,
1819 .error_strings = tcp_error_strings,
1820 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1823 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1824 foreach_tcp_state_next
1827 .format_trace = format_tcp_rx_trace_short,
1831 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1834 VLIB_REGISTER_NODE (tcp6_established_node) =
1836 .function = tcp6_established,
1837 .name = "tcp6-established",
1838 /* Takes a vector of packets. */
1839 .vector_size = sizeof (u32),
1840 .n_errors = TCP_N_ERROR,
1841 .error_strings = tcp_error_strings,
1842 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1845 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1846 foreach_tcp_state_next
1849 .format_trace = format_tcp_rx_trace_short,
1854 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1856 vlib_node_registration_t tcp4_syn_sent_node;
1857 vlib_node_registration_t tcp6_syn_sent_node;
1860 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
1862 transport_connection_t *tmp = 0;
1868 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
1869 && (tc->state == TCP_STATE_LISTEN
1870 || tc->c_rmt_port == hdr->src_port));
1874 handle = session_lookup_half_open_handle (&tc->connection);
1875 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
1876 tc->c_transport_proto,
1881 if (tmp->lcl_port == hdr->dst_port
1882 && tmp->rmt_port == hdr->src_port)
1884 TCP_DBG ("half-open is valid!");
1892 * Lookup transport connection
1894 static tcp_connection_t *
1895 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
1899 transport_connection_t *tconn;
1900 tcp_connection_t *tc;
1904 ip4 = vlib_buffer_get_current (b);
1905 tcp = ip4_next_header (ip4);
1906 tconn = session_lookup_connection_wt4 (fib_index,
1911 TRANSPORT_PROTO_TCP,
1913 tc = tcp_get_connection_from_transport (tconn);
1914 ASSERT (tcp_lookup_is_valid (tc, tcp));
1919 ip6 = vlib_buffer_get_current (b);
1920 tcp = ip6_next_header (ip6);
1921 tconn = session_lookup_connection_wt6 (fib_index,
1926 TRANSPORT_PROTO_TCP,
1928 tc = tcp_get_connection_from_transport (tconn);
1929 ASSERT (tcp_lookup_is_valid (tc, tcp));
1935 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1936 vlib_frame_t * from_frame, int is_ip4)
1938 tcp_main_t *tm = vnet_get_tcp_main ();
1939 u32 n_left_from, next_index, *from, *to_next;
1940 u32 my_thread_index = vm->thread_index, errors = 0;
1942 from = vlib_frame_vector_args (from_frame);
1943 n_left_from = from_frame->n_vectors;
1945 next_index = node->cached_next_index;
1947 while (n_left_from > 0)
1951 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1953 while (n_left_from > 0 && n_left_to_next > 0)
1955 u32 bi0, ack0, seq0;
1958 tcp_header_t *tcp0 = 0;
1959 tcp_connection_t *tc0;
1960 tcp_connection_t *new_tc0;
1961 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1968 n_left_to_next -= 1;
1970 b0 = vlib_get_buffer (vm, bi0);
1972 tcp_half_open_connection_get (vnet_buffer (b0)->
1973 tcp.connection_index);
1974 if (PREDICT_FALSE (tc0 == 0))
1976 error0 = TCP_ERROR_INVALID_CONNECTION;
1980 /* Half-open completed recently but the connection was't removed
1981 * yet by the owning thread */
1982 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
1984 /* Make sure the connection actually exists */
1985 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
1986 my_thread_index, is_ip4));
1990 ack0 = vnet_buffer (b0)->tcp.ack_number;
1991 seq0 = vnet_buffer (b0)->tcp.seq_number;
1992 tcp0 = tcp_buffer_hdr (b0);
1994 /* Crude check to see if the connection handle does not match
1995 * the packet. Probably connection just switched to established */
1996 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
1997 || tcp0->src_port != tc0->c_rmt_port))
2001 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
2004 /* SYNs, FINs and data consume sequence numbers */
2005 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
2006 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
2009 * 1. check the ACK bit
2013 * If the ACK bit is set
2014 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2015 * the RST bit is set, if so drop the segment and return)
2016 * <SEQ=SEG.ACK><CTL=RST>
2017 * and discard the segment. Return.
2018 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2022 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2024 clib_warning ("ack not in rcv wnd");
2025 if (!tcp_rst (tcp0))
2026 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2030 /* Make sure ACK is valid */
2031 if (seq_gt (tc0->snd_una, ack0))
2033 clib_warning ("ack invalid");
2039 * 2. check the RST bit
2044 /* If ACK is acceptable, signal client that peer is not
2045 * willing to accept connection and drop connection*/
2047 tcp_connection_reset (tc0);
2052 * 3. check the security and precedence (skipped)
2056 * 4. check the SYN bit
2059 /* No SYN flag. Drop. */
2060 if (!tcp_syn (tcp0))
2062 clib_warning ("not synack");
2067 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2069 clib_warning ("options parse fail");
2073 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2074 * current thread pool. */
2075 pool_get (tm->connections[my_thread_index], new_tc0);
2076 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2077 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2078 new_tc0->c_thread_index = my_thread_index;
2079 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2080 new_tc0->irs = seq0;
2081 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2082 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2083 TCP_TIMER_HANDLE_INVALID;
2085 /* If this is not the owning thread, wait for syn retransmit to
2086 * expire and cleanup then */
2087 if (tcp_half_open_connection_cleanup (tc0))
2088 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2090 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2092 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2093 new_tc0->tsval_recent_age = tcp_time_now ();
2096 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2097 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2099 /* RFC1323: SYN and SYN-ACK wnd not scaled */
2100 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
2101 new_tc0->snd_wl1 = seq0;
2102 new_tc0->snd_wl2 = ack0;
2104 tcp_connection_init_vars (new_tc0);
2106 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2107 if (PREDICT_TRUE (tcp_ack (tcp0)))
2109 /* Our SYN is ACKed: we have iss < ack = snd_una */
2111 /* TODO Dequeue acknowledged segments if we support Fast Open */
2112 new_tc0->snd_una = ack0;
2113 new_tc0->state = TCP_STATE_ESTABLISHED;
2115 /* Make sure las is initialized for the wnd computation */
2116 new_tc0->rcv_las = new_tc0->rcv_nxt;
2118 /* Notify app that we have connection. If session layer can't
2119 * allocate session send reset */
2120 if (stream_session_connect_notify (&new_tc0->connection, 0))
2122 clib_warning ("connect notify fail");
2123 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2124 tcp_connection_cleanup (new_tc0);
2128 /* Make sure after data segment processing ACK is sent */
2129 new_tc0->flags |= TCP_CONN_SNDACK;
2131 /* Update rtt with the syn-ack sample */
2132 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2133 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2135 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2138 new_tc0->state = TCP_STATE_SYN_RCVD;
2140 /* Notify app that we have connection */
2141 if (stream_session_connect_notify (&new_tc0->connection, 0))
2143 tcp_connection_cleanup (new_tc0);
2144 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2145 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2150 tcp_init_snd_vars (tc0);
2151 tcp_make_synack (new_tc0, b0);
2152 next0 = tcp_next_output (is_ip4);
2157 /* Read data, if any */
2158 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2161 error0 = tcp_segment_rcv (tm, new_tc0, b0, &next0);
2162 if (error0 == TCP_ERROR_PURE_ACK)
2163 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2167 tcp_make_ack (new_tc0, b0);
2168 next0 = tcp_next_output (new_tc0->c_is_ip4);
2173 b0->error = error0 ? node->errors[error0] : 0;
2175 ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2177 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2178 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2179 clib_memcpy (&t0->tcp_connection, tc0,
2180 sizeof (t0->tcp_connection));
2183 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2184 n_left_to_next, bi0, next0);
2187 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2190 errors = session_manager_flush_enqueue_events (my_thread_index);
2194 vlib_node_increment_counter (vm, tcp4_established_node.index,
2195 TCP_ERROR_EVENT_FIFO_FULL, errors);
2197 vlib_node_increment_counter (vm, tcp6_established_node.index,
2198 TCP_ERROR_EVENT_FIFO_FULL, errors);
2201 return from_frame->n_vectors;
2205 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2206 vlib_frame_t * from_frame)
2208 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2212 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2213 vlib_frame_t * from_frame)
2215 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2219 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2221 .function = tcp4_syn_sent,
2222 .name = "tcp4-syn-sent",
2223 /* Takes a vector of packets. */
2224 .vector_size = sizeof (u32),
2225 .n_errors = TCP_N_ERROR,
2226 .error_strings = tcp_error_strings,
2227 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2230 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2231 foreach_tcp_state_next
2234 .format_trace = format_tcp_rx_trace_short,
2238 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2241 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2243 .function = tcp6_syn_sent_rcv,
2244 .name = "tcp6-syn-sent",
2245 /* Takes a vector of packets. */
2246 .vector_size = sizeof (u32),
2247 .n_errors = TCP_N_ERROR,
2248 .error_strings = tcp_error_strings,
2249 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2252 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2253 foreach_tcp_state_next
2256 .format_trace = format_tcp_rx_trace_short,
2260 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2263 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2264 * as per RFC793 p. 64
2267 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2268 vlib_frame_t * from_frame, int is_ip4)
2270 tcp_main_t *tm = vnet_get_tcp_main ();
2271 u32 n_left_from, next_index, *from, *to_next;
2272 u32 my_thread_index = vm->thread_index, errors = 0;
2274 from = vlib_frame_vector_args (from_frame);
2275 n_left_from = from_frame->n_vectors;
2277 next_index = node->cached_next_index;
2279 while (n_left_from > 0)
2283 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2285 while (n_left_from > 0 && n_left_to_next > 0)
2289 tcp_header_t *tcp0 = 0;
2290 tcp_connection_t *tc0;
2291 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
2299 n_left_to_next -= 1;
2301 b0 = vlib_get_buffer (vm, bi0);
2302 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2304 if (PREDICT_FALSE (tc0 == 0))
2306 error0 = TCP_ERROR_INVALID_CONNECTION;
2310 tcp0 = tcp_buffer_hdr (b0);
2311 is_fin0 = tcp_is_fin (tcp0);
2313 /* SYNs, FINs and data consume sequence numbers */
2314 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2315 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2319 tcp_connection_t *tmp;
2321 tcp_lookup_connection (tc0->c_fib_index, b0, my_thread_index,
2323 if (tmp->state != tc0->state)
2325 clib_warning ("state changed");
2332 * Special treatment for CLOSED
2336 case TCP_STATE_CLOSED:
2342 * For all other states (except LISTEN)
2345 /* 1-4: check SEQ, RST, SYN */
2346 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2349 error0 = TCP_ERROR_SEGMENT_INVALID;
2353 /* 5: check the ACK field */
2356 case TCP_STATE_SYN_RCVD:
2358 * If the segment acknowledgment is not acceptable, form a
2360 * <SEQ=SEG.ACK><CTL=RST>
2363 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2365 TCP_DBG ("connection not accepted");
2366 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2370 /* Update rtt and rto */
2371 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2373 /* Switch state to ESTABLISHED */
2374 tc0->state = TCP_STATE_ESTABLISHED;
2376 /* Initialize session variables */
2377 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2378 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2379 << tc0->rcv_opts.wscale;
2380 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2381 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2382 stream_session_accept_notify (&tc0->connection);
2384 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2385 tcp_retransmit_timer_reset (tc0);
2386 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2387 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2389 case TCP_STATE_ESTABLISHED:
2390 /* We can get packets in established state here because they
2391 * were enqueued before state change */
2392 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2396 case TCP_STATE_FIN_WAIT_1:
2397 /* In addition to the processing for the ESTABLISHED state, if
2398 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2399 * continue processing in that state. */
2400 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2403 /* Still have to send the FIN */
2404 if (tc0->flags & TCP_CONN_FINPNDG)
2406 /* TX fifo finally drained */
2407 if (!stream_session_tx_fifo_max_dequeue (&tc0->connection))
2410 /* If FIN is ACKed */
2411 else if (tc0->snd_una == tc0->snd_una_max)
2413 tc0->state = TCP_STATE_FIN_WAIT_2;
2414 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2416 /* Stop all retransmit timers because we have nothing more
2417 * to send. Enable waitclose though because we're willing to
2418 * wait for peer's FIN but not indefinitely. */
2419 tcp_connection_timers_reset (tc0);
2420 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2423 case TCP_STATE_FIN_WAIT_2:
2424 /* In addition to the processing for the ESTABLISHED state, if
2425 * the retransmission queue is empty, the user's CLOSE can be
2426 * acknowledged ("ok") but do not delete the TCB. */
2427 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2430 case TCP_STATE_CLOSE_WAIT:
2431 /* Do the same processing as for the ESTABLISHED state. */
2432 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2435 case TCP_STATE_CLOSING:
2436 /* In addition to the processing for the ESTABLISHED state, if
2437 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2438 * otherwise ignore the segment. */
2439 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2442 tc0->state = TCP_STATE_TIME_WAIT;
2443 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2444 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2448 case TCP_STATE_LAST_ACK:
2449 /* The only thing that [should] arrive in this state is an
2450 * acknowledgment of our FIN. If our FIN is now acknowledged,
2451 * delete the TCB, enter the CLOSED state, and return. */
2453 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2455 error0 = TCP_ERROR_ACK_INVALID;
2459 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2460 /* Apparently our ACK for the peer's FIN was lost */
2461 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2467 tc0->state = TCP_STATE_CLOSED;
2468 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2469 tcp_connection_timers_reset (tc0);
2471 /* Don't delete the connection/session yet. Instead, wait a
2472 * reasonable amount of time until the pipes are cleared. In
2473 * particular, this makes sure that we won't have dead sessions
2474 * when processing events on the tx path */
2475 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2480 case TCP_STATE_TIME_WAIT:
2481 /* The only thing that can arrive in this state is a
2482 * retransmission of the remote FIN. Acknowledge it, and restart
2483 * the 2 MSL timeout. */
2485 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2488 tcp_make_ack (tc0, b0);
2489 next0 = tcp_next_output (is_ip4);
2490 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2499 /* 6: check the URG bit TODO */
2501 /* 7: process the segment text */
2504 case TCP_STATE_ESTABLISHED:
2505 case TCP_STATE_FIN_WAIT_1:
2506 case TCP_STATE_FIN_WAIT_2:
2507 if (vnet_buffer (b0)->tcp.data_len)
2508 error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
2512 case TCP_STATE_CLOSE_WAIT:
2513 case TCP_STATE_CLOSING:
2514 case TCP_STATE_LAST_ACK:
2515 case TCP_STATE_TIME_WAIT:
2516 /* This should not occur, since a FIN has been received from the
2517 * remote side. Ignore the segment text. */
2521 /* 8: check the FIN bit */
2527 case TCP_STATE_ESTABLISHED:
2528 case TCP_STATE_SYN_RCVD:
2529 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2530 tcp_connection_timers_reset (tc0);
2531 tcp_make_fin (tc0, b0);
2533 next0 = tcp_next_output (tc0->c_is_ip4);
2534 stream_session_disconnect_notify (&tc0->connection);
2535 tc0->state = TCP_STATE_CLOSE_WAIT;
2536 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2538 case TCP_STATE_CLOSE_WAIT:
2539 case TCP_STATE_CLOSING:
2540 case TCP_STATE_LAST_ACK:
2543 case TCP_STATE_FIN_WAIT_1:
2544 tc0->state = TCP_STATE_CLOSING;
2545 tcp_make_ack (tc0, b0);
2546 next0 = tcp_next_output (is_ip4);
2547 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2548 /* Wait for ACK but not forever */
2549 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2551 case TCP_STATE_FIN_WAIT_2:
2552 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2553 tc0->state = TCP_STATE_TIME_WAIT;
2554 tcp_connection_timers_reset (tc0);
2555 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2556 tcp_make_ack (tc0, b0);
2557 next0 = tcp_next_output (is_ip4);
2558 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2560 case TCP_STATE_TIME_WAIT:
2561 /* Remain in the TIME-WAIT state. Restart the time-wait
2564 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2567 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2570 b0->error = error0 ? node->errors[error0] : 0;
2572 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2574 tcp_rx_trace_t *t0 =
2575 vlib_add_trace (vm, node, b0, sizeof (*t0));
2576 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2579 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2580 n_left_to_next, bi0, next0);
2583 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2586 errors = session_manager_flush_enqueue_events (my_thread_index);
2590 vlib_node_increment_counter (vm, tcp4_established_node.index,
2591 TCP_ERROR_EVENT_FIFO_FULL, errors);
2593 vlib_node_increment_counter (vm, tcp6_established_node.index,
2594 TCP_ERROR_EVENT_FIFO_FULL, errors);
2597 return from_frame->n_vectors;
2601 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2602 vlib_frame_t * from_frame)
2604 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2608 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2609 vlib_frame_t * from_frame)
2611 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2615 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2617 .function = tcp4_rcv_process,
2618 .name = "tcp4-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 (tcp4_rcv_process_node, tcp4_rcv_process);
2637 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2639 .function = tcp6_rcv_process,
2640 .name = "tcp6-rcv-process",
2641 /* Takes a vector of packets. */
2642 .vector_size = sizeof (u32),
2643 .n_errors = TCP_N_ERROR,
2644 .error_strings = tcp_error_strings,
2645 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2648 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2649 foreach_tcp_state_next
2652 .format_trace = format_tcp_rx_trace_short,
2656 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2658 vlib_node_registration_t tcp4_listen_node;
2659 vlib_node_registration_t tcp6_listen_node;
2662 * LISTEN state processing as per RFC 793 p. 65
2665 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2666 vlib_frame_t * from_frame, int is_ip4)
2668 u32 n_left_from, next_index, *from, *to_next;
2669 u32 my_thread_index = vm->thread_index;
2671 from = vlib_frame_vector_args (from_frame);
2672 n_left_from = from_frame->n_vectors;
2674 next_index = node->cached_next_index;
2676 while (n_left_from > 0)
2680 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2682 while (n_left_from > 0 && n_left_to_next > 0)
2687 tcp_header_t *th0 = 0;
2688 tcp_connection_t *lc0;
2691 tcp_connection_t *child0;
2692 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2699 n_left_to_next -= 1;
2701 b0 = vlib_get_buffer (vm, bi0);
2702 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2706 ip40 = vlib_buffer_get_current (b0);
2707 th0 = ip4_next_header (ip40);
2711 ip60 = vlib_buffer_get_current (b0);
2712 th0 = ip6_next_header (ip60);
2715 /* Create child session. For syn-flood protection use filter */
2717 /* 1. first check for an RST: handled in dispatch */
2718 /* if (tcp_rst (th0))
2721 /* 2. second check for an ACK: handled in dispatch */
2722 /* if (tcp_ack (th0))
2724 tcp_send_reset (b0, is_ip4);
2728 /* 3. check for a SYN (did that already) */
2730 /* Make sure connection wasn't just created */
2732 tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
2734 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
2736 error0 = TCP_ERROR_CREATE_EXISTS;
2740 /* Create child session and send SYN-ACK */
2741 child0 = tcp_connection_new (my_thread_index);
2742 child0->c_lcl_port = lc0->c_lcl_port;
2743 child0->c_rmt_port = th0->src_port;
2744 child0->c_is_ip4 = is_ip4;
2745 child0->state = TCP_STATE_SYN_RCVD;
2749 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2750 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2754 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2755 sizeof (ip6_address_t));
2756 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2757 sizeof (ip6_address_t));
2760 if (stream_session_accept (&child0->connection, lc0->c_s_index,
2763 clib_warning ("session accept fail");
2764 tcp_connection_cleanup (child0);
2765 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2769 if (tcp_options_parse (th0, &child0->rcv_opts))
2771 clib_warning ("options parse fail");
2775 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2776 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2777 child0->rcv_las = child0->rcv_nxt;
2779 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2780 * segments are used to initialize PAWS. */
2781 if (tcp_opts_tstamp (&child0->rcv_opts))
2783 child0->tsval_recent = child0->rcv_opts.tsval;
2784 child0->tsval_recent_age = tcp_time_now ();
2787 if (tcp_opts_wscale (&child0->rcv_opts))
2788 child0->snd_wscale = child0->rcv_opts.wscale;
2790 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2791 << child0->snd_wscale;
2792 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2793 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2795 tcp_connection_init_vars (child0);
2796 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
2798 /* Reuse buffer to make syn-ack and send */
2799 tcp_make_synack (child0, b0);
2800 next0 = tcp_next_output (is_ip4);
2801 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
2804 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2806 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2807 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2808 clib_memcpy (&t0->tcp_connection, lc0,
2809 sizeof (t0->tcp_connection));
2812 b0->error = node->errors[error0];
2814 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2815 n_left_to_next, bi0, next0);
2818 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2820 return from_frame->n_vectors;
2824 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2825 vlib_frame_t * from_frame)
2827 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2831 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2832 vlib_frame_t * from_frame)
2834 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2838 VLIB_REGISTER_NODE (tcp4_listen_node) =
2840 .function = tcp4_listen,
2841 .name = "tcp4-listen",
2842 /* Takes a vector of packets. */
2843 .vector_size = sizeof (u32),
2844 .n_errors = TCP_N_ERROR,
2845 .error_strings = tcp_error_strings,
2846 .n_next_nodes = TCP_LISTEN_N_NEXT,
2849 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2850 foreach_tcp_state_next
2853 .format_trace = format_tcp_rx_trace_short,
2857 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2860 VLIB_REGISTER_NODE (tcp6_listen_node) =
2862 .function = tcp6_listen,
2863 .name = "tcp6-listen",
2864 /* Takes a vector of packets. */
2865 .vector_size = sizeof (u32),
2866 .n_errors = TCP_N_ERROR,
2867 .error_strings = tcp_error_strings,
2868 .n_next_nodes = TCP_LISTEN_N_NEXT,
2871 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2872 foreach_tcp_state_next
2875 .format_trace = format_tcp_rx_trace_short,
2879 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2881 vlib_node_registration_t tcp4_input_node;
2882 vlib_node_registration_t tcp6_input_node;
2884 typedef enum _tcp_input_next
2886 TCP_INPUT_NEXT_DROP,
2887 TCP_INPUT_NEXT_LISTEN,
2888 TCP_INPUT_NEXT_RCV_PROCESS,
2889 TCP_INPUT_NEXT_SYN_SENT,
2890 TCP_INPUT_NEXT_ESTABLISHED,
2891 TCP_INPUT_NEXT_RESET,
2892 TCP_INPUT_NEXT_PUNT,
2896 #define foreach_tcp4_input_next \
2897 _ (DROP, "error-drop") \
2898 _ (LISTEN, "tcp4-listen") \
2899 _ (RCV_PROCESS, "tcp4-rcv-process") \
2900 _ (SYN_SENT, "tcp4-syn-sent") \
2901 _ (ESTABLISHED, "tcp4-established") \
2902 _ (RESET, "tcp4-reset") \
2903 _ (PUNT, "error-punt")
2905 #define foreach_tcp6_input_next \
2906 _ (DROP, "error-drop") \
2907 _ (LISTEN, "tcp6-listen") \
2908 _ (RCV_PROCESS, "tcp6-rcv-process") \
2909 _ (SYN_SENT, "tcp6-syn-sent") \
2910 _ (ESTABLISHED, "tcp6-established") \
2911 _ (RESET, "tcp6-reset") \
2912 _ (PUNT, "error-punt")
2914 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2917 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2918 vlib_frame_t * from_frame, int is_ip4)
2920 u32 n_left_from, next_index, *from, *to_next;
2921 u32 my_thread_index = vm->thread_index;
2922 tcp_main_t *tm = vnet_get_tcp_main ();
2924 from = vlib_frame_vector_args (from_frame);
2925 n_left_from = from_frame->n_vectors;
2926 next_index = node->cached_next_index;
2927 tcp_set_time_now (my_thread_index);
2929 while (n_left_from > 0)
2933 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2935 while (n_left_from > 0 && n_left_to_next > 0)
2937 int n_advance_bytes0, n_data_bytes0;
2938 u32 bi0, fib_index0;
2940 tcp_header_t *tcp0 = 0;
2941 tcp_connection_t *tc0;
2942 transport_connection_t *tconn;
2945 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2953 n_left_to_next -= 1;
2955 b0 = vlib_get_buffer (vm, bi0);
2956 vnet_buffer (b0)->tcp.flags = 0;
2957 fib_index0 = vnet_buffer (b0)->ip.fib_index;
2959 /* Checksum computed by ipx_local no need to compute again */
2963 ip40 = vlib_buffer_get_current (b0);
2964 tcp0 = ip4_next_header (ip40);
2965 n_advance_bytes0 = (ip4_header_bytes (ip40)
2966 + tcp_header_bytes (tcp0));
2967 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2970 session_lookup_connection_wt4 (fib_index0, &ip40->dst_address,
2972 tcp0->dst_port, tcp0->src_port,
2973 TRANSPORT_PROTO_TCP,
2975 tc0 = tcp_get_connection_from_transport (tconn);
2976 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
2980 ip60 = vlib_buffer_get_current (b0);
2981 tcp0 = ip6_next_header (ip60);
2982 n_advance_bytes0 = tcp_header_bytes (tcp0);
2983 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2985 n_advance_bytes0 += sizeof (ip60[0]);
2987 session_lookup_connection_wt6 (fib_index0, &ip60->dst_address,
2989 tcp0->dst_port, tcp0->src_port,
2990 TRANSPORT_PROTO_TCP,
2992 tc0 = tcp_get_connection_from_transport (tconn);
2993 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
2997 if (PREDICT_FALSE (n_advance_bytes0 < 0))
2999 error0 = TCP_ERROR_LENGTH;
3003 /* Session exists */
3004 if (PREDICT_TRUE (0 != tc0))
3006 /* Save connection index */
3007 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
3008 vnet_buffer (b0)->tcp.seq_number =
3009 clib_net_to_host_u32 (tcp0->seq_number);
3010 vnet_buffer (b0)->tcp.ack_number =
3011 clib_net_to_host_u32 (tcp0->ack_number);
3013 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
3014 - (u8 *) vlib_buffer_get_current (b0);
3015 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
3016 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
3018 flags0 = tcp0->flags & filter_flags;
3019 next0 = tm->dispatch_table[tc0->state][flags0].next;
3020 error0 = tm->dispatch_table[tc0->state][flags0].error;
3022 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH
3023 || next0 == TCP_INPUT_NEXT_RESET))
3025 /* Overload tcp flags to store state */
3026 tcp_state_t state0 = tc0->state;
3027 vnet_buffer (b0)->tcp.flags = tc0->state;
3029 if (error0 == TCP_ERROR_DISPATCH)
3030 clib_warning ("disp error state %U flags %U",
3031 format_tcp_state, state0, format_tcp_flags,
3037 if ((is_ip4 && tm->punt_unknown4) ||
3038 (!is_ip4 && tm->punt_unknown6))
3040 next0 = TCP_INPUT_NEXT_PUNT;
3041 error0 = TCP_ERROR_PUNT;
3046 next0 = TCP_INPUT_NEXT_RESET;
3047 error0 = TCP_ERROR_NO_LISTENER;
3052 b0->error = error0 ? node->errors[error0] : 0;
3054 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3056 tcp_rx_trace_t *t0 =
3057 vlib_add_trace (vm, node, b0, sizeof (*t0));
3058 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3060 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
3061 n_left_to_next, bi0, next0);
3064 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3067 return from_frame->n_vectors;
3071 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3072 vlib_frame_t * from_frame)
3074 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3078 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3079 vlib_frame_t * from_frame)
3081 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3085 VLIB_REGISTER_NODE (tcp4_input_node) =
3087 .function = tcp4_input,
3088 .name = "tcp4-input",
3089 /* Takes a vector of packets. */
3090 .vector_size = sizeof (u32),
3091 .n_errors = TCP_N_ERROR,
3092 .error_strings = tcp_error_strings,
3093 .n_next_nodes = TCP_INPUT_N_NEXT,
3096 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3097 foreach_tcp4_input_next
3100 .format_buffer = format_tcp_header,
3101 .format_trace = format_tcp_rx_trace,
3105 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3108 VLIB_REGISTER_NODE (tcp6_input_node) =
3110 .function = tcp6_input,
3111 .name = "tcp6-input",
3112 /* Takes a vector of packets. */
3113 .vector_size = sizeof (u32),
3114 .n_errors = TCP_N_ERROR,
3115 .error_strings = tcp_error_strings,
3116 .n_next_nodes = TCP_INPUT_N_NEXT,
3119 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3120 foreach_tcp6_input_next
3123 .format_buffer = format_tcp_header,
3124 .format_trace = format_tcp_rx_trace,
3128 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3131 tcp_dispatch_table_init (tcp_main_t * tm)
3134 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3135 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3137 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3138 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3141 #define _(t,f,n,e) \
3143 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3144 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3147 /* SYNs for new connections -> tcp-listen. */
3148 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3149 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3150 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_NONE);
3151 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3153 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3154 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3155 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3156 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3157 /* SYN-ACK for a SYN */
3158 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3160 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3161 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3162 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3164 /* ACK for for established connection -> tcp-established. */
3165 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3166 /* FIN for for established connection -> tcp-established. */
3167 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3168 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3170 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3171 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3173 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3174 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3176 /* ACK or FIN-ACK to our FIN */
3177 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3178 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3180 /* FIN in reply to our FIN from the other side */
3181 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3182 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3183 /* FIN confirming that the peer (app) has closed */
3184 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3185 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3186 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3188 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3189 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3191 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3192 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3193 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3195 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3196 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3197 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3199 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3200 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3201 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3202 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3203 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3204 TCP_ERROR_CONNECTION_CLOSED);
3209 tcp_input_init (vlib_main_t * vm)
3211 clib_error_t *error = 0;
3212 tcp_main_t *tm = vnet_get_tcp_main ();
3214 if ((error = vlib_call_init_function (vm, tcp_init)))
3217 /* Initialize dispatch table. */
3218 tcp_dispatch_table_init (tm);
3223 VLIB_INIT_FUNCTION (tcp_input_init);
3226 * fd.io coding-style-patch-verification: ON
3229 * eval: (c-set-style "gnu")