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 + 4 * j));
210 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 4 * 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 tc->tsval_recent = tc->rcv_opts.tsval;
255 tc->tsval_recent_age = tcp_time_now ();
260 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
262 * It first verifies if segment has a wrapped sequence number (PAWS) and then
263 * does the processing associated to the first four steps (ignoring security
264 * and precedence): sequence number, rst bit and syn bit checks.
266 * @return 0 if segments passes validation.
269 tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0,
270 vlib_buffer_t * b0, tcp_header_t * th0, u32 * next0)
272 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
275 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts)))
280 if (tcp_segment_check_paws (tc0))
284 clib_warning ("paws failed\n%U", format_tcp_connection, tc0, 2);
285 clib_warning ("seq %u seq_end %u ack %u",
286 vnet_buffer (b0)->tcp.seq_number - tc0->irs,
287 vnet_buffer (b0)->tcp.seq_end - tc0->irs,
288 vnet_buffer (b0)->tcp.ack_number - tc0->iss);
290 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
291 vnet_buffer (b0)->tcp.seq_end);
293 /* If it just so happens that a segment updates tsval_recent for a
294 * segment over 24 days old, invalidate tsval_recent. */
295 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
298 /* Age isn't reset until we get a valid tsval (bsd inspired) */
299 tc0->tsval_recent = 0;
300 clib_warning ("paws failed - really old segment. REALLY?");
304 /* Drop after ack if not rst */
307 tcp_make_ack (tc0, b0);
308 *next0 = tcp_next_output (tc0->c_is_ip4);
309 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
315 /* 1st: check sequence number */
316 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
317 vnet_buffer (b0)->tcp.seq_end))
319 /* If our window is 0 and the packet is in sequence, let it pass
320 * through for ack processing. It should be dropped later.*/
321 if (tc0->rcv_wnd == 0
322 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
324 /* TODO Should segment be tagged? */
328 /* If not RST, send dup ack */
331 tcp_make_ack (tc0, b0);
332 *next0 = tcp_next_output (tc0->c_is_ip4);
333 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
339 /* 2nd: check the RST bit */
342 tcp_connection_reset (tc0);
346 /* 3rd: check security and precedence (skip) */
348 /* 4th: check the SYN bit */
351 tcp_send_reset (b0, tc0->c_is_ip4);
355 /* If segment in window, save timestamp */
356 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
357 vnet_buffer (b0)->tcp.seq_end);
362 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
364 /* SND.UNA =< SEG.ACK =< SND.NXT */
365 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
366 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
370 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
372 * Note that although the original article, srtt and rttvar are scaled
373 * to minimize round-off errors, here we don't. Instead, we rely on
374 * better precision time measurements.
376 * TODO support us rtt resolution
379 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
385 err = mrtt - tc->srtt;
386 tc->srtt += err >> 3;
388 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
389 * The increase should be bound */
390 tc->rttvar += ((int) clib_abs (err) - (int) tc->rttvar) >> 2;
394 /* First measurement. */
396 tc->rttvar = mrtt >> 1;
401 tcp_update_rto (tcp_connection_t * tc)
403 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
406 /** Update RTT estimate and RTO timer
408 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
409 * timing. Middle boxes are known to fiddle with TCP options so we
410 * should give higher priority to ACK timing.
412 * return 1 if valid rtt 0 otherwise
415 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
420 /* Determine if only rtx bytes are acked. TODO XXX fast retransmit */
421 rtx_acked = tc->rto_boff && (tc->bytes_acked <= tc->snd_mss);
423 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
424 * RTT because they're ambiguous. */
425 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq) && !rtx_acked)
427 mrtt = tcp_time_now () - tc->rtt_ts;
429 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
430 * snd_una, i.e., the left side of the send window:
431 * seq_lt (tc->snd_una, ack). Note: last condition could be dropped, we don't
432 * try to update rtt for dupacks */
433 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr
436 mrtt = tcp_time_now () - tc->rcv_opts.tsecr;
439 /* Allow measuring of a new RTT */
442 /* If ACK moves left side of the wnd make sure boff is 0, even if mrtt is
447 /* Ignore dubious measurements */
448 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
451 tcp_estimate_rtt (tc, mrtt);
458 * Dequeue bytes that have been acked and while at it update RTT estimates.
461 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
463 /* Dequeue the newly ACKed add SACKed bytes */
464 stream_session_dequeue_drop (&tc->connection,
465 tc->bytes_acked + tc->sack_sb.snd_una_adv);
467 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
469 /* Update rtt and rto */
470 tcp_update_rtt (tc, ack);
472 /* If everything has been acked, stop retransmit timer
473 * otherwise update. */
474 tcp_retransmit_timer_update (tc);
478 * Check if duplicate ack as per RFC5681 Sec. 2
481 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
484 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
485 && seq_gt (tc->snd_una_max, tc->snd_una)
486 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
487 && (prev_snd_wnd == tc->snd_wnd));
491 * Checks if ack is a congestion control event.
494 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
495 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
497 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
498 * defined to be 'duplicate' */
499 *is_dack = tc->sack_sb.last_sacked_bytes
500 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
502 return (*is_dack || tcp_in_cong_recovery (tc));
506 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
508 sack_scoreboard_hole_t *next, *prev;
510 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
512 next = pool_elt_at_index (sb->holes, hole->next);
513 next->prev = hole->prev;
517 sb->tail = hole->prev;
520 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
522 prev = pool_elt_at_index (sb->holes, hole->prev);
523 prev->next = hole->next;
527 sb->head = hole->next;
530 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
531 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
533 pool_put (sb->holes, hole);
536 sack_scoreboard_hole_t *
537 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
540 sack_scoreboard_hole_t *hole, *next, *prev;
543 pool_get (sb->holes, hole);
544 memset (hole, 0, sizeof (*hole));
548 hole_index = hole - sb->holes;
550 prev = scoreboard_get_hole (sb, prev_index);
553 hole->prev = prev - sb->holes;
554 hole->next = prev->next;
556 if ((next = scoreboard_next_hole (sb, hole)))
557 next->prev = hole_index;
559 prev->next = hole_index;
563 sb->head = hole_index;
564 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
565 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
572 scoreboard_update_lost (tcp_connection_t * tc, sack_scoreboard_t * sb)
574 sack_scoreboard_hole_t *hole, *prev;
575 u32 bytes = 0, blks = 0;
578 hole = scoreboard_last_hole (sb);
582 if (seq_gt (sb->high_sacked, hole->end))
584 bytes = sb->high_sacked - hole->end;
588 while ((prev = scoreboard_prev_hole (sb, hole))
589 && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
590 && blks < TCP_DUPACK_THRESHOLD))
592 bytes += hole->start - prev->end;
600 sb->lost_bytes += scoreboard_hole_bytes (hole);
602 hole = scoreboard_prev_hole (sb, hole);
607 * Figure out the next hole to retransmit
609 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
611 sack_scoreboard_hole_t *
612 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
613 sack_scoreboard_hole_t * start,
615 u8 * can_rescue, u8 * snd_limited)
617 sack_scoreboard_hole_t *hole = 0;
619 hole = start ? start : scoreboard_first_hole (sb);
620 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
621 hole = scoreboard_next_hole (sb, hole);
623 /* Nothing, return */
626 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
630 /* Rule (1): if higher than rxt, less than high_sacked and lost */
631 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
633 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
637 /* Rule (2): output takes care of transmitting new data */
638 if (!have_sent_1_smss)
641 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
643 /* Rule (3): if hole not lost */
644 else if (seq_lt (hole->start, sb->high_sacked))
647 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
649 /* Rule (4): if hole beyond high_sacked */
652 ASSERT (seq_geq (hole->start, sb->high_sacked));
655 /* HighRxt MUST NOT be updated */
660 if (hole && seq_lt (sb->high_rxt, hole->start))
661 sb->high_rxt = hole->start;
667 scoreboard_init_high_rxt (sack_scoreboard_t * sb)
669 sack_scoreboard_hole_t *hole;
670 hole = scoreboard_first_hole (sb);
671 sb->high_rxt = hole->start;
672 sb->cur_rxt_hole = sb->head;
676 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
678 sack_scoreboard_t *sb = &tc->sack_sb;
679 sack_block_t *blk, tmp;
680 sack_scoreboard_hole_t *hole, *next_hole, *last_hole, *new_hole;
681 u32 blk_index = 0, old_sacked_bytes, hole_index;
684 sb->last_sacked_bytes = 0;
686 old_sacked_bytes = sb->sacked_bytes;
687 sb->last_bytes_delivered = 0;
689 if (!tcp_opts_sack (&tc->rcv_opts)
690 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
693 /* Remove invalid blocks */
694 blk = tc->rcv_opts.sacks;
695 while (blk < vec_end (tc->rcv_opts.sacks))
697 if (seq_lt (blk->start, blk->end)
698 && seq_gt (blk->start, tc->snd_una)
699 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_nxt))
704 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
707 /* Add block for cumulative ack */
708 if (seq_gt (ack, tc->snd_una))
710 tmp.start = tc->snd_una;
712 vec_add1 (tc->rcv_opts.sacks, tmp);
715 if (vec_len (tc->rcv_opts.sacks) == 0)
718 /* Make sure blocks are ordered */
719 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
720 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
721 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
723 tmp = tc->rcv_opts.sacks[i];
724 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
725 tc->rcv_opts.sacks[j] = tmp;
728 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
730 /* If no holes, insert the first that covers all outstanding bytes */
731 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
732 tc->snd_una, tc->snd_una_max);
733 sb->tail = scoreboard_hole_index (sb, last_hole);
734 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
735 sb->high_sacked = tmp.end;
739 /* If we have holes but snd_una_max is beyond the last hole, update
741 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
742 last_hole = scoreboard_last_hole (sb);
743 if (seq_gt (tc->snd_una_max, sb->high_sacked)
744 && seq_gt (tc->snd_una_max, last_hole->end))
745 last_hole->end = tc->snd_una_max;
748 /* Walk the holes with the SACK blocks */
749 hole = pool_elt_at_index (sb->holes, sb->head);
750 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
752 blk = &tc->rcv_opts.sacks[blk_index];
754 if (seq_leq (blk->start, hole->start))
756 /* Block covers hole. Remove hole */
757 if (seq_geq (blk->end, hole->end))
759 next_hole = scoreboard_next_hole (sb, hole);
761 /* Byte accounting */
762 if (seq_leq (hole->end, ack))
764 /* Bytes lost because snd_wnd left edge advances */
765 if (next_hole && seq_leq (next_hole->start, ack))
766 sb->last_bytes_delivered += next_hole->start - hole->end;
768 sb->last_bytes_delivered += ack - hole->end;
772 sb->sacked_bytes += scoreboard_hole_bytes (hole);
775 /* About to remove last hole */
776 if (hole == last_hole)
778 sb->tail = hole->prev;
779 last_hole = scoreboard_last_hole (sb);
780 /* keep track of max byte sacked for when the last hole
782 if (seq_gt (hole->end, sb->high_sacked))
783 sb->high_sacked = hole->end;
786 /* snd_una needs to be advanced */
787 if (blk->end == ack && seq_geq (ack, hole->end))
789 if (next_hole && seq_lt (ack, next_hole->start))
791 sb->snd_una_adv = next_hole->start - ack;
793 /* all these can be delivered */
794 sb->last_bytes_delivered += sb->snd_una_adv;
798 sb->snd_una_adv = sb->high_sacked - ack;
799 sb->last_bytes_delivered += sb->snd_una_adv;
803 scoreboard_remove_hole (sb, hole);
806 /* Partial 'head' overlap */
809 if (seq_gt (blk->end, hole->start))
811 sb->sacked_bytes += blk->end - hole->start;
812 hole->start = blk->end;
819 /* Hole must be split */
820 if (seq_lt (blk->end, hole->end))
822 sb->sacked_bytes += blk->end - blk->start;
823 hole_index = scoreboard_hole_index (sb, hole);
824 new_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
827 /* Pool might've moved */
828 hole = scoreboard_get_hole (sb, hole_index);
829 hole->end = blk->start;
831 /* New or split of tail */
832 if ((last_hole->end == new_hole->end)
833 || seq_lt (last_hole->end, new_hole->start))
835 last_hole = new_hole;
836 sb->tail = scoreboard_hole_index (sb, new_hole);
841 else if (seq_leq (blk->start, hole->end))
843 sb->sacked_bytes += hole->end - blk->start;
844 hole->end = blk->start;
847 hole = scoreboard_next_hole (sb, hole);
851 sb->last_sacked_bytes = sb->sacked_bytes - old_sacked_bytes;
852 sb->sacked_bytes -= sb->last_bytes_delivered;
853 scoreboard_update_lost (tc, sb);
857 * Try to update snd_wnd based on feedback received from peer.
859 * If successful, and new window is 'effectively' 0, activate persist
863 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
865 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
866 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
867 if (seq_lt (tc->snd_wl1, seq)
868 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
870 tc->snd_wnd = snd_wnd;
873 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
875 if (tc->snd_wnd < tc->snd_mss)
877 /* Set persist timer if not set and we just got 0 wnd */
878 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
879 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
880 tcp_persist_timer_set (tc);
884 tcp_persist_timer_reset (tc);
885 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
895 tcp_cc_init_congestion (tcp_connection_t * tc)
897 tcp_fastrecovery_on (tc);
898 tc->snd_congestion = tc->snd_una_max;
899 tc->cc_algo->congestion (tc);
900 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
904 tcp_cc_recovery_exit (tcp_connection_t * tc)
910 tcp_recovery_off (tc);
914 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
916 tc->cc_algo->recovered (tc);
917 tc->snd_rxt_bytes = 0;
919 tcp_fastrecovery_off (tc);
920 tcp_fastrecovery_1_smss_off (tc);
924 tcp_cc_congestion_undo (tcp_connection_t * tc)
926 tc->cwnd = tc->prev_cwnd;
927 tc->ssthresh = tc->prev_ssthresh;
928 tc->snd_nxt = tc->snd_una_max;
930 if (tcp_in_recovery (tc))
931 tcp_cc_recovery_exit (tc);
932 ASSERT (tc->rto_boff == 0);
933 /* TODO extend for fastrecovery */
937 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
939 return (tc->snd_rxt_ts
940 && tcp_opts_tstamp (&tc->rcv_opts)
941 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
945 tcp_cc_recover (tcp_connection_t * tc)
947 ASSERT (tcp_in_cong_recovery (tc));
948 if (tcp_cc_is_spurious_retransmit (tc))
950 tcp_cc_congestion_undo (tc);
954 if (tcp_in_recovery (tc))
955 tcp_cc_recovery_exit (tc);
956 else if (tcp_in_fastrecovery (tc))
957 tcp_cc_fastrecovery_exit (tc);
959 ASSERT (tc->rto_boff == 0);
960 ASSERT (!tcp_in_cong_recovery (tc));
962 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
967 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
969 ASSERT (!tcp_in_cong_recovery (tc));
971 /* Congestion avoidance */
972 tc->cc_algo->rcv_ack (tc);
973 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
975 /* If a cumulative ack, make sure dupacks is 0 */
978 /* When dupacks hits the threshold we only enter fast retransmit if
979 * cumulative ack covers more than snd_congestion. Should snd_una
980 * wrap this test may fail under otherwise valid circumstances.
981 * Therefore, proactively update snd_congestion when wrap detected. */
983 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
984 && seq_gt (tc->snd_congestion, tc->snd_una)))
985 tc->snd_congestion = tc->snd_una - 1;
989 tcp_should_fastrecover_sack (tcp_connection_t * tc)
991 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
995 tcp_should_fastrecover (tcp_connection_t * tc)
997 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
998 || tcp_should_fastrecover_sack (tc));
1002 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1005 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1006 * it account for the bytes that left the network.
1010 ASSERT (tc->snd_una != tc->snd_una_max
1011 || tc->sack_sb.last_sacked_bytes);
1014 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1016 ASSERT (tcp_in_fastrecovery (tc));
1017 /* Pure duplicate ack. If some data got acked, it's handled lower */
1018 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1021 else if (tcp_should_fastrecover (tc))
1023 /* Things are already bad */
1024 if (tcp_in_cong_recovery (tc))
1026 tc->rcv_dupacks = 0;
1027 goto partial_ack_test;
1030 /* If of of the two conditions lower hold, reset dupacks
1031 * 1) Cumulative ack does not cover more than congestion threshold
1032 * 2) RFC6582 heuristic to avoid multiple fast retransmits
1034 if (seq_leq (tc->snd_una, tc->snd_congestion)
1035 || tc->rcv_opts.tsecr != tc->tsecr_last_ack)
1037 tc->rcv_dupacks = 0;
1041 tcp_cc_init_congestion (tc);
1042 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1044 /* The first segment MUST be retransmitted */
1045 tcp_retransmit_first_unacked (tc);
1047 /* Post retransmit update cwnd to ssthresh and account for the
1048 * three segments that have left the network and should've been
1049 * buffered at the receiver XXX */
1050 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1052 /* If cwnd allows, send more data */
1053 if (tcp_opts_sack_permitted (&tc->rcv_opts)
1054 && scoreboard_first_hole (&tc->sack_sb))
1056 scoreboard_init_high_rxt (&tc->sack_sb);
1057 tcp_fast_retransmit_sack (tc);
1061 tcp_fast_retransmit_no_sack (tc);
1066 else if (!tc->bytes_acked
1067 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1069 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1078 if (!tc->bytes_acked)
1083 * Legitimate ACK. 1) See if we can exit recovery
1085 /* XXX limit this only to first partial ack? */
1086 tcp_retransmit_timer_update (tc);
1088 if (seq_geq (tc->snd_una, tc->snd_congestion))
1090 /* If spurious return, we've already updated everything */
1091 if (tcp_cc_recover (tc))
1094 tc->snd_nxt = tc->snd_una_max;
1096 /* Treat as congestion avoidance ack */
1097 tc->cc_algo->rcv_ack (tc);
1098 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1103 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1105 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1107 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1108 * reset dupacks to 0 */
1109 tc->rcv_dupacks = 0;
1111 tcp_retransmit_first_unacked (tc);
1113 /* Post RTO timeout don't try anything fancy */
1114 if (tcp_in_recovery (tc))
1117 /* Remove retransmitted bytes that have been delivered */
1118 if (tc->sack_sb.last_bytes_delivered
1119 && seq_gt (tc->sack_sb.high_rxt, tc->snd_una))
1121 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1122 * remove sacked bytes delivered */
1123 tc->snd_rxt_bytes -= tc->sack_sb.last_bytes_delivered;
1127 /* Either all retransmitted holes have been acked, or we're
1128 * "in the blind" and retransmitting segment by segment */
1129 tc->snd_rxt_bytes = 0;
1132 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1135 * Since this was a partial ack, try to retransmit some more data
1137 tcp_fast_retransmit (tc);
1141 tcp_cc_init (tcp_connection_t * tc)
1143 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
1144 tc->cc_algo->init (tc);
1148 * Process incoming ACK
1151 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1152 tcp_header_t * th, u32 * next, u32 * error)
1154 u32 prev_snd_wnd, prev_snd_una;
1157 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1158 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1160 /* If we have outstanding data and this is within the window, accept it,
1161 * probably retransmit has timed out. Otherwise ACK segment and then
1163 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1165 tcp_make_ack (tc, b);
1166 *next = tcp_next_output (tc->c_is_ip4);
1167 *error = TCP_ERROR_ACK_INVALID;
1168 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1169 vnet_buffer (b)->tcp.ack_number);
1173 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1174 vnet_buffer (b)->tcp.ack_number);
1176 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1177 *error = TCP_ERROR_ACK_FUTURE;
1180 /* If old ACK, probably it's an old dupack */
1181 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1183 *error = TCP_ERROR_ACK_OLD;
1184 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1185 vnet_buffer (b)->tcp.ack_number);
1186 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1188 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
1189 tcp_cc_handle_event (tc, 1);
1191 /* Don't drop yet */
1196 * Looks okay, process feedback
1199 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1201 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1202 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1204 prev_snd_wnd = tc->snd_wnd;
1205 prev_snd_una = tc->snd_una;
1206 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1207 vnet_buffer (b)->tcp.ack_number,
1208 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1209 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1210 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1211 tcp_validate_txf_size (tc, tc->bytes_acked);
1213 if (tc->bytes_acked)
1214 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1217 * Check if we have congestion event
1220 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1222 tcp_cc_handle_event (tc, is_dack);
1223 *error = TCP_ERROR_ACK_DUP;
1224 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1225 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1229 * Update congestion control (slow start/congestion avoidance)
1231 tcp_cc_update (tc, b);
1237 * Build SACK list as per RFC2018.
1239 * Makes sure the first block contains the segment that generated the current
1240 * ACK and the following ones are the ones most recently reported in SACK
1243 * @param tc TCP connection for which the SACK list is updated
1244 * @param start Start sequence number of the newest SACK block
1245 * @param end End sequence of the newest SACK block
1248 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1250 sack_block_t *new_list = 0, *block = 0;
1253 /* If the first segment is ooo add it to the list. Last write might've moved
1254 * rcv_nxt over the first segment. */
1255 if (seq_lt (tc->rcv_nxt, start))
1257 vec_add2 (new_list, block, 1);
1258 block->start = start;
1262 /* Find the blocks still worth keeping. */
1263 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1265 /* Discard if rcv_nxt advanced beyond current block */
1266 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1269 /* Merge or drop if segment overlapped by the new segment */
1270 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1271 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1273 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1274 new_list[0].start = tc->snd_sacks[i].start;
1275 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1276 new_list[0].end = tc->snd_sacks[i].end;
1280 /* Save to new SACK list if we have space. */
1281 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1283 vec_add1 (new_list, tc->snd_sacks[i]);
1287 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1289 /* Replace old vector with new one */
1290 vec_free (tc->snd_sacks);
1291 tc->snd_sacks = new_list;
1294 /** Enqueue data for delivery to application */
1296 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1301 /* Pure ACK. Update rcv_nxt and be done. */
1302 if (PREDICT_FALSE (data_len == 0))
1304 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
1305 return TCP_ERROR_PURE_ACK;
1308 written = stream_session_enqueue_data (&tc->connection, b, 0,
1309 1 /* queue event */ , 1);
1311 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1313 /* Update rcv_nxt */
1314 if (PREDICT_TRUE (written == data_len))
1316 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
1318 /* If more data written than expected, account for out-of-order bytes. */
1319 else if (written > data_len)
1321 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end + written - data_len;
1323 /* Send ACK confirming the update */
1324 tc->flags |= TCP_CONN_SNDACK;
1326 else if (written > 0)
1328 /* We've written something but FIFO is probably full now */
1329 tc->rcv_nxt += written;
1331 /* Depending on how fast the app is, all remaining buffers in burst will
1332 * not be enqueued. Inform peer */
1333 tc->flags |= TCP_CONN_SNDACK;
1335 return TCP_ERROR_PARTIALLY_ENQUEUED;
1339 tc->flags |= TCP_CONN_SNDACK;
1340 return TCP_ERROR_FIFO_FULL;
1343 /* Update SACK list if need be */
1344 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1346 /* Remove SACK blocks that have been delivered */
1347 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1350 return TCP_ERROR_ENQUEUED;
1353 /** Enqueue out-of-order data */
1355 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1358 stream_session_t *s0;
1361 /* Pure ACK. Do nothing */
1362 if (PREDICT_FALSE (data_len == 0))
1364 return TCP_ERROR_PURE_ACK;
1367 /* Enqueue out-of-order data with absolute offset */
1368 rv = stream_session_enqueue_data (&tc->connection, b,
1369 vnet_buffer (b)->tcp.seq_number,
1370 0 /* queue event */ , 0);
1372 /* Nothing written */
1375 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1376 return TCP_ERROR_FIFO_FULL;
1379 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1381 /* Update SACK list if in use */
1382 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1384 ooo_segment_t *newest;
1387 s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
1389 /* Get the newest segment from the fifo */
1390 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1391 start = ooo_segment_offset (s0->server_rx_fifo, newest);
1392 end = ooo_segment_end_offset (s0->server_rx_fifo, newest);
1394 tcp_update_sack_list (tc, start, end);
1397 return TCP_ERROR_ENQUEUED;
1401 * Check if ACK could be delayed. If ack can be delayed, it should return
1402 * true for a full frame. If we're always acking return 0.
1405 tcp_can_delack (tcp_connection_t * tc)
1407 /* Send ack if ... */
1409 /* just sent a rcv wnd 0 */
1410 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1411 /* constrained to send ack */
1412 || (tc->flags & TCP_CONN_SNDACK) != 0
1413 /* we're almost out of tx wnd */
1414 || tcp_available_snd_space (tc) < 2 * tc->snd_mss)
1421 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1422 u16 n_data_bytes, u32 * next0)
1424 u32 error = 0, n_bytes_to_drop;
1426 /* Handle out-of-order data */
1427 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1429 /* Old sequence numbers allowed through because they overlapped
1431 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1433 error = TCP_ERROR_SEGMENT_OLD;
1434 *next0 = TCP_NEXT_DROP;
1436 /* Completely in the past (possible retransmit) */
1437 if (seq_lt (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1440 /* Chop off the bytes in the past */
1441 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1442 n_data_bytes -= n_bytes_to_drop;
1443 vlib_buffer_advance (b, n_bytes_to_drop);
1448 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1450 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1451 * cwnd on remote peer when congested 2) acks leaving should have the
1452 * latest rcv_wnd since the burst may eaten up all of it, so only the
1453 * old ones could be filtered.
1456 /* RFC2581: Send DUPACK for fast retransmit */
1457 tcp_make_ack (tc, b);
1458 *next0 = tcp_next_output (tc->c_is_ip4);
1460 /* Mark as DUPACK. We may filter these in output if
1461 * the burst fills the holes. */
1463 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1465 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1471 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1472 * segments can be enqueued after fifo tail offset changes. */
1473 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1475 if (n_data_bytes == 0)
1477 *next0 = TCP_NEXT_DROP;
1481 /* Check if ACK can be delayed */
1482 if (tcp_can_delack (tc))
1484 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1485 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1489 *next0 = tcp_next_output (tc->c_is_ip4);
1490 tcp_make_ack (tc, b);
1498 tcp_header_t tcp_header;
1499 tcp_connection_t tcp_connection;
1503 format_tcp_rx_trace (u8 * s, va_list * args)
1505 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1506 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1507 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1508 uword indent = format_get_indent (s);
1510 s = format (s, "%U\n%U%U",
1511 format_tcp_header, &t->tcp_header, 128,
1512 format_white_space, indent,
1513 format_tcp_connection, &t->tcp_connection, 1);
1519 format_tcp_rx_trace_short (u8 * s, va_list * args)
1521 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1522 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1523 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1525 s = format (s, "%d -> %d (%U)",
1526 clib_net_to_host_u16 (t->tcp_header.src_port),
1527 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1528 t->tcp_connection.state);
1534 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1535 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1539 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1543 th0 = tcp_buffer_hdr (b0);
1545 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1549 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1551 if (PREDICT_TRUE (!val))
1555 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1557 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1561 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1562 vlib_frame_t * from_frame, int is_ip4)
1564 u32 n_left_from, next_index, *from, *to_next;
1565 u32 my_thread_index = vm->thread_index, errors = 0;
1566 tcp_main_t *tm = vnet_get_tcp_main ();
1569 from = vlib_frame_vector_args (from_frame);
1570 n_left_from = from_frame->n_vectors;
1572 next_index = node->cached_next_index;
1574 while (n_left_from > 0)
1578 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1579 while (n_left_from > 0 && n_left_to_next > 0)
1583 tcp_header_t *th0 = 0;
1584 tcp_connection_t *tc0;
1585 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1592 n_left_to_next -= 1;
1594 b0 = vlib_get_buffer (vm, bi0);
1595 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1598 if (PREDICT_FALSE (tc0 == 0))
1600 error0 = TCP_ERROR_INVALID_CONNECTION;
1604 th0 = tcp_buffer_hdr (b0);
1605 is_fin = (th0->flags & TCP_FLAG_FIN) != 0;
1607 /* SYNs, FINs and data consume sequence numbers */
1608 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1609 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1611 /* TODO header prediction fast path */
1613 /* 1-4: check SEQ, RST, SYN */
1614 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1616 error0 = TCP_ERROR_SEGMENT_INVALID;
1617 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1618 vnet_buffer (b0)->tcp.seq_number,
1619 vnet_buffer (b0)->tcp.seq_end);
1623 /* 5: check the ACK field */
1624 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1629 /* 6: check the URG bit TODO */
1631 /* 7: process the segment text */
1633 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1634 error0 = tcp_segment_rcv (tm, tc0, b0,
1635 vnet_buffer (b0)->tcp.data_len, &next0);
1637 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1638 * dangling reference. */
1640 /* 8: check the FIN bit */
1643 /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
1644 * wait for session to call close. To avoid lingering
1645 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1646 tc0->state = TCP_STATE_CLOSE_WAIT;
1647 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1648 stream_session_disconnect_notify (&tc0->connection);
1649 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1653 b0->error = node->errors[error0];
1654 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1656 tcp_rx_trace_t *t0 =
1657 vlib_add_trace (vm, node, b0, sizeof (*t0));
1658 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1661 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1662 n_left_to_next, bi0, next0);
1665 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1668 errors = session_manager_flush_enqueue_events (my_thread_index);
1669 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1670 return from_frame->n_vectors;
1674 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1675 vlib_frame_t * from_frame)
1677 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1681 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1682 vlib_frame_t * from_frame)
1684 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1688 VLIB_REGISTER_NODE (tcp4_established_node) =
1690 .function = tcp4_established,
1691 .name = "tcp4-established",
1692 /* Takes a vector of packets. */
1693 .vector_size = sizeof (u32),
1694 .n_errors = TCP_N_ERROR,
1695 .error_strings = tcp_error_strings,
1696 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1699 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1700 foreach_tcp_state_next
1703 .format_trace = format_tcp_rx_trace_short,
1707 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1710 VLIB_REGISTER_NODE (tcp6_established_node) =
1712 .function = tcp6_established,
1713 .name = "tcp6-established",
1714 /* Takes a vector of packets. */
1715 .vector_size = sizeof (u32),
1716 .n_errors = TCP_N_ERROR,
1717 .error_strings = tcp_error_strings,
1718 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1721 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1722 foreach_tcp_state_next
1725 .format_trace = format_tcp_rx_trace_short,
1730 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1732 vlib_node_registration_t tcp4_syn_sent_node;
1733 vlib_node_registration_t tcp6_syn_sent_node;
1736 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1737 vlib_frame_t * from_frame, int is_ip4)
1739 tcp_main_t *tm = vnet_get_tcp_main ();
1740 u32 n_left_from, next_index, *from, *to_next;
1741 u32 my_thread_index = vm->thread_index, errors = 0;
1742 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
1744 from = vlib_frame_vector_args (from_frame);
1745 n_left_from = from_frame->n_vectors;
1747 next_index = node->cached_next_index;
1749 while (n_left_from > 0)
1753 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1755 while (n_left_from > 0 && n_left_to_next > 0)
1757 u32 bi0, ack0, seq0;
1760 tcp_header_t *tcp0 = 0;
1761 tcp_connection_t *tc0;
1762 tcp_connection_t *new_tc0;
1763 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1770 n_left_to_next -= 1;
1772 b0 = vlib_get_buffer (vm, bi0);
1774 tcp_half_open_connection_get (vnet_buffer (b0)->
1775 tcp.connection_index);
1777 ack0 = vnet_buffer (b0)->tcp.ack_number;
1778 seq0 = vnet_buffer (b0)->tcp.seq_number;
1779 tcp0 = tcp_buffer_hdr (b0);
1782 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1785 /* SYNs, FINs and data consume sequence numbers */
1786 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1787 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
1790 * 1. check the ACK bit
1794 * If the ACK bit is set
1795 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
1796 * the RST bit is set, if so drop the segment and return)
1797 * <SEQ=SEG.ACK><CTL=RST>
1798 * and discard the segment. Return.
1799 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
1803 if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt)
1805 if (!tcp_rst (tcp0))
1806 tcp_send_reset (b0, is_ip4);
1811 /* Make sure ACK is valid */
1812 if (tc0->snd_una > ack0)
1817 * 2. check the RST bit
1822 /* If ACK is acceptable, signal client that peer is not
1823 * willing to accept connection and drop connection*/
1826 stream_session_connect_notify (&tc0->connection, sst,
1828 tcp_connection_cleanup (tc0);
1834 * 3. check the security and precedence (skipped)
1838 * 4. check the SYN bit
1841 /* No SYN flag. Drop. */
1842 if (!tcp_syn (tcp0))
1845 /* Stop connection establishment and retransmit timers */
1846 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
1847 tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT_SYN);
1849 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
1850 * current thread pool. */
1851 pool_get (tm->connections[my_thread_index], new_tc0);
1852 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
1854 new_tc0->c_thread_index = my_thread_index;
1855 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
1857 /* Cleanup half-open connection XXX lock */
1858 pool_put (tm->half_open_connections, tc0);
1860 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
1861 new_tc0->irs = seq0;
1864 if (tcp_options_parse (tcp0, &new_tc0->rcv_opts))
1867 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
1869 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
1870 new_tc0->tsval_recent_age = tcp_time_now ();
1873 if (tcp_opts_wscale (&new_tc0->rcv_opts))
1874 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
1877 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
1878 new_tc0->snd_wl1 = seq0;
1879 new_tc0->snd_wl2 = ack0;
1881 tcp_connection_init_vars (new_tc0);
1883 /* SYN-ACK: See if we can switch to ESTABLISHED state */
1886 /* Our SYN is ACKed: we have iss < ack = snd_una */
1888 /* TODO Dequeue acknowledged segments if we support Fast Open */
1889 new_tc0->snd_una = ack0;
1890 new_tc0->state = TCP_STATE_ESTABLISHED;
1892 /* Make sure las is initialized for the wnd computation */
1893 new_tc0->rcv_las = new_tc0->rcv_nxt;
1895 /* Notify app that we have connection */
1896 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1898 stream_session_init_fifos_pointers (&new_tc0->connection,
1901 /* Make sure after data segment processing ACK is sent */
1902 new_tc0->flags |= TCP_CONN_SNDACK;
1904 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
1907 new_tc0->state = TCP_STATE_SYN_RCVD;
1909 /* Notify app that we have connection */
1910 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1911 stream_session_init_fifos_pointers (&new_tc0->connection,
1914 tcp_make_synack (new_tc0, b0);
1915 next0 = tcp_next_output (is_ip4);
1920 /* Read data, if any */
1921 if (vnet_buffer (b0)->tcp.data_len)
1923 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1924 error0 = tcp_segment_rcv (tm, new_tc0, b0,
1925 vnet_buffer (b0)->tcp.data_len,
1927 if (error0 == TCP_ERROR_PURE_ACK)
1928 error0 = TCP_ERROR_SYN_ACKS_RCVD;
1932 tcp_make_ack (new_tc0, b0);
1933 next0 = tcp_next_output (new_tc0->c_is_ip4);
1938 b0->error = error0 ? node->errors[error0] : 0;
1939 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1941 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1942 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
1943 clib_memcpy (&t0->tcp_connection, tc0,
1944 sizeof (t0->tcp_connection));
1947 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1948 n_left_to_next, bi0, next0);
1951 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1954 errors = session_manager_flush_enqueue_events (my_thread_index);
1958 vlib_node_increment_counter (vm, tcp4_established_node.index,
1959 TCP_ERROR_EVENT_FIFO_FULL, errors);
1961 vlib_node_increment_counter (vm, tcp6_established_node.index,
1962 TCP_ERROR_EVENT_FIFO_FULL, errors);
1965 return from_frame->n_vectors;
1969 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
1970 vlib_frame_t * from_frame)
1972 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1976 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
1977 vlib_frame_t * from_frame)
1979 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1983 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
1985 .function = tcp4_syn_sent,
1986 .name = "tcp4-syn-sent",
1987 /* Takes a vector of packets. */
1988 .vector_size = sizeof (u32),
1989 .n_errors = TCP_N_ERROR,
1990 .error_strings = tcp_error_strings,
1991 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1994 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1995 foreach_tcp_state_next
1998 .format_trace = format_tcp_rx_trace_short,
2002 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2005 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2007 .function = tcp6_syn_sent_rcv,
2008 .name = "tcp6-syn-sent",
2009 /* Takes a vector of packets. */
2010 .vector_size = sizeof (u32),
2011 .n_errors = TCP_N_ERROR,
2012 .error_strings = tcp_error_strings,
2013 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2016 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2017 foreach_tcp_state_next
2020 .format_trace = format_tcp_rx_trace_short,
2024 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2026 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2027 * as per RFC793 p. 64
2030 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2031 vlib_frame_t * from_frame, int is_ip4)
2033 tcp_main_t *tm = vnet_get_tcp_main ();
2034 u32 n_left_from, next_index, *from, *to_next;
2035 u32 my_thread_index = vm->thread_index, errors = 0;
2037 from = vlib_frame_vector_args (from_frame);
2038 n_left_from = from_frame->n_vectors;
2040 next_index = node->cached_next_index;
2042 while (n_left_from > 0)
2046 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2048 while (n_left_from > 0 && n_left_to_next > 0)
2052 tcp_header_t *tcp0 = 0;
2053 tcp_connection_t *tc0;
2054 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
2061 n_left_to_next -= 1;
2063 b0 = vlib_get_buffer (vm, bi0);
2064 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2066 if (PREDICT_FALSE (tc0 == 0))
2068 error0 = TCP_ERROR_INVALID_CONNECTION;
2072 tcp0 = tcp_buffer_hdr (b0);
2074 /* SYNs, FINs and data consume sequence numbers */
2075 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2076 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0)
2077 + vnet_buffer (b0)->tcp.data_len;
2080 * Special treatment for CLOSED
2084 case TCP_STATE_CLOSED:
2090 * For all other states (except LISTEN)
2093 /* 1-4: check SEQ, RST, SYN */
2095 (tcp_segment_validate (vm, tc0, b0, tcp0, &next0)))
2097 error0 = TCP_ERROR_SEGMENT_INVALID;
2101 /* 5: check the ACK field */
2104 case TCP_STATE_SYN_RCVD:
2106 * If the segment acknowledgment is not acceptable, form a
2108 * <SEQ=SEG.ACK><CTL=RST>
2111 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2113 tcp_send_reset (b0, is_ip4);
2117 /* Update rtt and rto */
2118 tc0->bytes_acked = 1;
2119 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2121 /* Switch state to ESTABLISHED */
2122 tc0->state = TCP_STATE_ESTABLISHED;
2124 /* Initialize session variables */
2125 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2126 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2127 << tc0->rcv_opts.wscale;
2128 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2129 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2131 /* Shoulder tap the server */
2132 stream_session_accept_notify (&tc0->connection);
2134 /* Reset SYN-ACK retransmit timer */
2135 tcp_retransmit_timer_reset (tc0);
2137 case TCP_STATE_ESTABLISHED:
2138 /* We can get packets in established state here because they
2139 * were enqueued before state change */
2140 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2144 case TCP_STATE_FIN_WAIT_1:
2145 /* In addition to the processing for the ESTABLISHED state, if
2146 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2147 * continue processing in that state. */
2148 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2151 /* If FIN is ACKed */
2152 if (tc0->snd_una == tc0->snd_una_max)
2154 tc0->state = TCP_STATE_FIN_WAIT_2;
2155 /* Stop all timers, 2MSL will be set lower */
2156 tcp_connection_timers_reset (tc0);
2159 case TCP_STATE_FIN_WAIT_2:
2160 /* In addition to the processing for the ESTABLISHED state, if
2161 * the retransmission queue is empty, the user's CLOSE can be
2162 * acknowledged ("ok") but do not delete the TCB. */
2163 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2165 /* check if rtx queue is empty and ack CLOSE TODO */
2167 case TCP_STATE_CLOSE_WAIT:
2168 /* Do the same processing as for the ESTABLISHED state. */
2169 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2172 case TCP_STATE_CLOSING:
2173 /* In addition to the processing for the ESTABLISHED state, if
2174 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2175 * otherwise ignore the segment. */
2176 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2179 /* XXX test that send queue empty */
2180 tc0->state = TCP_STATE_TIME_WAIT;
2184 case TCP_STATE_LAST_ACK:
2185 /* The only thing that [should] arrive in this state is an
2186 * acknowledgment of our FIN. If our FIN is now acknowledged,
2187 * delete the TCB, enter the CLOSED state, and return. */
2189 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2192 /* Apparently our FIN was lost */
2195 /* Don't "make" fin since that increments snd_nxt */
2200 tc0->state = TCP_STATE_CLOSED;
2202 /* Don't delete the connection/session yet. Instead, wait a
2203 * reasonable amount of time until the pipes are cleared. In
2204 * particular, this makes sure that we won't have dead sessions
2205 * when processing events on the tx path */
2206 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2208 /* Stop retransmit */
2209 tcp_retransmit_timer_reset (tc0);
2214 case TCP_STATE_TIME_WAIT:
2215 /* The only thing that can arrive in this state is a
2216 * retransmission of the remote FIN. Acknowledge it, and restart
2217 * the 2 MSL timeout. */
2219 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2222 tcp_make_ack (tc0, b0);
2223 tcp_timer_reset (tc0, TCP_TIMER_WAITCLOSE);
2224 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2233 /* 6: check the URG bit TODO */
2235 /* 7: process the segment text */
2238 case TCP_STATE_ESTABLISHED:
2239 case TCP_STATE_FIN_WAIT_1:
2240 case TCP_STATE_FIN_WAIT_2:
2241 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
2242 error0 = tcp_segment_rcv (tm, tc0, b0,
2243 vnet_buffer (b0)->tcp.data_len,
2246 case TCP_STATE_CLOSE_WAIT:
2247 case TCP_STATE_CLOSING:
2248 case TCP_STATE_LAST_ACK:
2249 case TCP_STATE_TIME_WAIT:
2250 /* This should not occur, since a FIN has been received from the
2251 * remote side. Ignore the segment text. */
2255 /* 8: check the FIN bit */
2256 if (!tcp_fin (tcp0))
2261 case TCP_STATE_ESTABLISHED:
2262 case TCP_STATE_SYN_RCVD:
2263 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2264 tcp_connection_timers_reset (tc0);
2265 tcp_make_fin (tc0, b0);
2266 next0 = tcp_next_output (tc0->c_is_ip4);
2267 stream_session_disconnect_notify (&tc0->connection);
2268 tc0->state = TCP_STATE_CLOSE_WAIT;
2270 case TCP_STATE_CLOSE_WAIT:
2271 case TCP_STATE_CLOSING:
2272 case TCP_STATE_LAST_ACK:
2275 case TCP_STATE_FIN_WAIT_1:
2276 tc0->state = TCP_STATE_TIME_WAIT;
2277 tcp_connection_timers_reset (tc0);
2278 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2280 case TCP_STATE_FIN_WAIT_2:
2281 /* Got FIN, send ACK! */
2282 tc0->state = TCP_STATE_TIME_WAIT;
2283 tcp_connection_timers_reset (tc0);
2284 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2285 tcp_make_ack (tc0, b0);
2286 next0 = tcp_next_output (is_ip4);
2288 case TCP_STATE_TIME_WAIT:
2289 /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
2292 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2295 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2298 b0->error = error0 ? node->errors[error0] : 0;
2300 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2302 tcp_rx_trace_t *t0 =
2303 vlib_add_trace (vm, node, b0, sizeof (*t0));
2304 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2307 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2308 n_left_to_next, bi0, next0);
2311 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2314 errors = session_manager_flush_enqueue_events (my_thread_index);
2318 vlib_node_increment_counter (vm, tcp4_established_node.index,
2319 TCP_ERROR_EVENT_FIFO_FULL, errors);
2321 vlib_node_increment_counter (vm, tcp6_established_node.index,
2322 TCP_ERROR_EVENT_FIFO_FULL, errors);
2325 return from_frame->n_vectors;
2329 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2330 vlib_frame_t * from_frame)
2332 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2336 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2337 vlib_frame_t * from_frame)
2339 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2343 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2345 .function = tcp4_rcv_process,
2346 .name = "tcp4-rcv-process",
2347 /* Takes a vector of packets. */
2348 .vector_size = sizeof (u32),
2349 .n_errors = TCP_N_ERROR,
2350 .error_strings = tcp_error_strings,
2351 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2354 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2355 foreach_tcp_state_next
2358 .format_trace = format_tcp_rx_trace_short,
2362 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2365 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2367 .function = tcp6_rcv_process,
2368 .name = "tcp6-rcv-process",
2369 /* Takes a vector of packets. */
2370 .vector_size = sizeof (u32),
2371 .n_errors = TCP_N_ERROR,
2372 .error_strings = tcp_error_strings,
2373 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2376 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2377 foreach_tcp_state_next
2380 .format_trace = format_tcp_rx_trace_short,
2384 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2386 vlib_node_registration_t tcp4_listen_node;
2387 vlib_node_registration_t tcp6_listen_node;
2390 * LISTEN state processing as per RFC 793 p. 65
2393 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2394 vlib_frame_t * from_frame, int is_ip4)
2396 u32 n_left_from, next_index, *from, *to_next;
2397 u32 my_thread_index = vm->thread_index;
2398 tcp_main_t *tm = vnet_get_tcp_main ();
2399 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
2401 from = vlib_frame_vector_args (from_frame);
2402 n_left_from = from_frame->n_vectors;
2404 next_index = node->cached_next_index;
2406 while (n_left_from > 0)
2410 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2412 while (n_left_from > 0 && n_left_to_next > 0)
2417 tcp_header_t *th0 = 0;
2418 tcp_connection_t *lc0;
2421 tcp_connection_t *child0;
2422 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2429 n_left_to_next -= 1;
2431 b0 = vlib_get_buffer (vm, bi0);
2432 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2436 ip40 = vlib_buffer_get_current (b0);
2437 th0 = ip4_next_header (ip40);
2441 ip60 = vlib_buffer_get_current (b0);
2442 th0 = ip6_next_header (ip60);
2445 /* Create child session. For syn-flood protection use filter */
2447 /* 1. first check for an RST: handled in dispatch */
2448 /* if (tcp_rst (th0))
2451 /* 2. second check for an ACK: handled in dispatch */
2452 /* if (tcp_ack (th0))
2454 tcp_send_reset (b0, is_ip4);
2458 /* 3. check for a SYN (did that already) */
2460 /* Create child session and send SYN-ACK */
2461 pool_get (tm->connections[my_thread_index], child0);
2462 memset (child0, 0, sizeof (*child0));
2464 child0->c_c_index = child0 - tm->connections[my_thread_index];
2465 child0->c_lcl_port = lc0->c_lcl_port;
2466 child0->c_rmt_port = th0->src_port;
2467 child0->c_is_ip4 = is_ip4;
2468 child0->c_thread_index = my_thread_index;
2469 child0->state = TCP_STATE_SYN_RCVD;
2473 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2474 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2478 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2479 sizeof (ip6_address_t));
2480 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2481 sizeof (ip6_address_t));
2484 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2487 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2491 if (tcp_options_parse (th0, &child0->rcv_opts))
2496 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2497 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2498 child0->rcv_las = child0->rcv_nxt;
2500 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2501 * segments are used to initialize PAWS. */
2502 if (tcp_opts_tstamp (&child0->rcv_opts))
2504 child0->tsval_recent = child0->rcv_opts.tsval;
2505 child0->tsval_recent_age = tcp_time_now ();
2508 if (tcp_opts_wscale (&child0->rcv_opts))
2509 child0->snd_wscale = child0->rcv_opts.wscale;
2512 child0->snd_wnd = clib_net_to_host_u16 (th0->window);
2513 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2514 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2516 tcp_connection_init_vars (child0);
2518 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0);
2520 /* Reuse buffer to make syn-ack and send */
2521 tcp_make_synack (child0, b0);
2522 next0 = tcp_next_output (is_ip4);
2524 /* Init fifo pointers after we have iss */
2525 stream_session_init_fifos_pointers (&child0->connection,
2529 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2531 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2532 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2533 clib_memcpy (&t0->tcp_connection, lc0,
2534 sizeof (t0->tcp_connection));
2537 b0->error = node->errors[error0];
2539 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2540 n_left_to_next, bi0, next0);
2543 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2545 return from_frame->n_vectors;
2549 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2550 vlib_frame_t * from_frame)
2552 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2556 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2557 vlib_frame_t * from_frame)
2559 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2563 VLIB_REGISTER_NODE (tcp4_listen_node) =
2565 .function = tcp4_listen,
2566 .name = "tcp4-listen",
2567 /* Takes a vector of packets. */
2568 .vector_size = sizeof (u32),
2569 .n_errors = TCP_N_ERROR,
2570 .error_strings = tcp_error_strings,
2571 .n_next_nodes = TCP_LISTEN_N_NEXT,
2574 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2575 foreach_tcp_state_next
2578 .format_trace = format_tcp_rx_trace_short,
2582 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2585 VLIB_REGISTER_NODE (tcp6_listen_node) =
2587 .function = tcp6_listen,
2588 .name = "tcp6-listen",
2589 /* Takes a vector of packets. */
2590 .vector_size = sizeof (u32),
2591 .n_errors = TCP_N_ERROR,
2592 .error_strings = tcp_error_strings,
2593 .n_next_nodes = TCP_LISTEN_N_NEXT,
2596 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2597 foreach_tcp_state_next
2600 .format_trace = format_tcp_rx_trace_short,
2604 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2606 vlib_node_registration_t tcp4_input_node;
2607 vlib_node_registration_t tcp6_input_node;
2609 typedef enum _tcp_input_next
2611 TCP_INPUT_NEXT_DROP,
2612 TCP_INPUT_NEXT_LISTEN,
2613 TCP_INPUT_NEXT_RCV_PROCESS,
2614 TCP_INPUT_NEXT_SYN_SENT,
2615 TCP_INPUT_NEXT_ESTABLISHED,
2616 TCP_INPUT_NEXT_RESET,
2620 #define foreach_tcp4_input_next \
2621 _ (DROP, "error-drop") \
2622 _ (LISTEN, "tcp4-listen") \
2623 _ (RCV_PROCESS, "tcp4-rcv-process") \
2624 _ (SYN_SENT, "tcp4-syn-sent") \
2625 _ (ESTABLISHED, "tcp4-established") \
2626 _ (RESET, "tcp4-reset")
2628 #define foreach_tcp6_input_next \
2629 _ (DROP, "error-drop") \
2630 _ (LISTEN, "tcp6-listen") \
2631 _ (RCV_PROCESS, "tcp6-rcv-process") \
2632 _ (SYN_SENT, "tcp6-syn-sent") \
2633 _ (ESTABLISHED, "tcp6-established") \
2634 _ (RESET, "tcp6-reset")
2636 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2639 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2640 vlib_frame_t * from_frame, int is_ip4)
2642 u32 n_left_from, next_index, *from, *to_next;
2643 u32 my_thread_index = vm->thread_index;
2644 tcp_main_t *tm = vnet_get_tcp_main ();
2646 from = vlib_frame_vector_args (from_frame);
2647 n_left_from = from_frame->n_vectors;
2649 next_index = node->cached_next_index;
2651 while (n_left_from > 0)
2655 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2657 while (n_left_from > 0 && n_left_to_next > 0)
2659 int n_advance_bytes0, n_data_bytes0;
2662 tcp_header_t *tcp0 = 0;
2663 tcp_connection_t *tc0;
2666 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2674 n_left_to_next -= 1;
2676 b0 = vlib_get_buffer (vm, bi0);
2677 vnet_buffer (b0)->tcp.flags = 0;
2679 /* Checksum computed by ipx_local no need to compute again */
2683 ip40 = vlib_buffer_get_current (b0);
2684 tcp0 = ip4_next_header (ip40);
2685 n_advance_bytes0 = (ip4_header_bytes (ip40)
2686 + tcp_header_bytes (tcp0));
2687 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2690 /* lookup session */
2692 (tcp_connection_t *)
2693 stream_session_lookup_transport4 (&ip40->dst_address,
2697 SESSION_TYPE_IP4_TCP,
2702 ip60 = vlib_buffer_get_current (b0);
2703 tcp0 = ip6_next_header (ip60);
2704 n_advance_bytes0 = tcp_header_bytes (tcp0);
2705 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2707 n_advance_bytes0 += sizeof (ip60[0]);
2710 (tcp_connection_t *)
2711 stream_session_lookup_transport6 (&ip60->src_address,
2715 SESSION_TYPE_IP6_TCP,
2720 if (PREDICT_FALSE (n_advance_bytes0 < 0))
2722 error0 = TCP_ERROR_LENGTH;
2726 /* Session exists */
2727 if (PREDICT_TRUE (0 != tc0))
2729 /* Save connection index */
2730 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2731 vnet_buffer (b0)->tcp.seq_number =
2732 clib_net_to_host_u32 (tcp0->seq_number);
2733 vnet_buffer (b0)->tcp.ack_number =
2734 clib_net_to_host_u32 (tcp0->ack_number);
2736 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
2737 - (u8 *) vlib_buffer_get_current (b0);
2738 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
2739 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
2741 flags0 = tcp0->flags & filter_flags;
2742 next0 = tm->dispatch_table[tc0->state][flags0].next;
2743 error0 = tm->dispatch_table[tc0->state][flags0].error;
2745 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH
2746 || next0 == TCP_INPUT_NEXT_RESET))
2748 /* Overload tcp flags to store state */
2749 tcp_state_t state0 = tc0->state;
2750 vnet_buffer (b0)->tcp.flags = tc0->state;
2752 if (error0 == TCP_ERROR_DISPATCH)
2753 clib_warning ("disp error state %U flags %U",
2754 format_tcp_state, state0, format_tcp_flags,
2761 next0 = TCP_INPUT_NEXT_RESET;
2762 error0 = TCP_ERROR_NO_LISTENER;
2766 b0->error = error0 ? node->errors[error0] : 0;
2768 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2770 tcp_rx_trace_t *t0 =
2771 vlib_add_trace (vm, node, b0, sizeof (*t0));
2772 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2774 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2775 n_left_to_next, bi0, next0);
2778 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2781 return from_frame->n_vectors;
2785 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2786 vlib_frame_t * from_frame)
2788 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2792 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2793 vlib_frame_t * from_frame)
2795 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2799 VLIB_REGISTER_NODE (tcp4_input_node) =
2801 .function = tcp4_input,
2802 .name = "tcp4-input",
2803 /* Takes a vector of packets. */
2804 .vector_size = sizeof (u32),
2805 .n_errors = TCP_N_ERROR,
2806 .error_strings = tcp_error_strings,
2807 .n_next_nodes = TCP_INPUT_N_NEXT,
2810 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2811 foreach_tcp4_input_next
2814 .format_buffer = format_tcp_header,
2815 .format_trace = format_tcp_rx_trace,
2819 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
2822 VLIB_REGISTER_NODE (tcp6_input_node) =
2824 .function = tcp6_input,
2825 .name = "tcp6-input",
2826 /* Takes a vector of packets. */
2827 .vector_size = sizeof (u32),
2828 .n_errors = TCP_N_ERROR,
2829 .error_strings = tcp_error_strings,
2830 .n_next_nodes = TCP_INPUT_N_NEXT,
2833 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2834 foreach_tcp6_input_next
2837 .format_buffer = format_tcp_header,
2838 .format_trace = format_tcp_rx_trace,
2842 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
2845 tcp_dispatch_table_init (tcp_main_t * tm)
2848 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
2849 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
2851 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
2852 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
2855 #define _(t,f,n,e) \
2857 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
2858 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
2861 /* SYNs for new connections -> tcp-listen. */
2862 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
2863 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
2864 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_NONE);
2865 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
2866 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2867 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2868 /* SYN-ACK for a SYN */
2869 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2871 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2872 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2873 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2875 /* ACK for for established connection -> tcp-established. */
2876 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2877 /* FIN for for established connection -> tcp-established. */
2878 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2879 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2881 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2882 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2884 /* ACK or FIN-ACK to our FIN */
2885 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2886 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
2888 /* FIN in reply to our FIN from the other side */
2889 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2890 /* FIN confirming that the peer (app) has closed */
2891 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2892 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2893 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2895 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2896 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2897 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2899 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2900 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2901 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2903 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_CONNECTION_CLOSED);
2904 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
2909 tcp_input_init (vlib_main_t * vm)
2911 clib_error_t *error = 0;
2912 tcp_main_t *tm = vnet_get_tcp_main ();
2914 if ((error = vlib_call_init_function (vm, tcp_init)))
2917 /* Initialize dispatch table. */
2918 tcp_dispatch_table_init (tm);
2923 VLIB_INIT_FUNCTION (tcp_input_init);
2926 * fd.io coding-style-patch-verification: ON
2929 * eval: (c-set-style "gnu")