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 tcp_options_parse (tcp_header_t * th, tcp_options_t * to)
119 u8 opt_len, opts_len, kind;
123 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
124 data = (const u8 *) (th + 1);
126 /* Zero out all flags but those set in SYN */
127 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE);
129 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
133 /* Get options length */
134 if (kind == TCP_OPTION_EOL)
136 else if (kind == TCP_OPTION_NOOP)
145 /* weird option length */
146 if (opt_len < 2 || opt_len > opts_len)
154 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
156 to->flags |= TCP_OPTS_FLAG_MSS;
157 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
160 case TCP_OPTION_WINDOW_SCALE:
161 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
163 to->flags |= TCP_OPTS_FLAG_WSCALE;
164 to->wscale = data[2];
165 if (to->wscale > TCP_MAX_WND_SCALE)
167 clib_warning ("Illegal window scaling value: %d",
169 to->wscale = TCP_MAX_WND_SCALE;
173 case TCP_OPTION_TIMESTAMP:
174 if (opt_len == TCP_OPTION_LEN_TIMESTAMP)
176 to->flags |= TCP_OPTS_FLAG_TSTAMP;
177 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
178 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
181 case TCP_OPTION_SACK_PERMITTED:
182 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
183 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
185 case TCP_OPTION_SACK_BLOCK:
186 /* If SACK permitted was not advertised or a SYN, break */
187 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
190 /* If too short or not correctly formatted, break */
191 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
194 to->flags |= TCP_OPTS_FLAG_SACK;
195 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
196 vec_reset_length (to->sacks);
197 for (j = 0; j < to->n_sack_blocks; j++)
199 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 4 * j));
200 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 4 * j));
201 vec_add1 (to->sacks, b);
205 /* Nothing to see here */
212 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
213 * timestamp to echo and it's less than tsval_recent, drop segment
214 * but still send an ACK in order to retain TCP's mechanism for detecting
215 * and recovering from half-open connections
217 * Or at least that's what the theory says. It seems that this might not work
218 * very well with packet reordering and fast retransmit. XXX
221 tcp_segment_check_paws (tcp_connection_t * tc)
223 return tcp_opts_tstamp (&tc->opt) && tc->tsval_recent
224 && timestamp_lt (tc->opt.tsval, tc->tsval_recent);
228 * Update tsval recent
231 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
234 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
235 * of an incoming segment:
236 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
237 * then the TSval from the segment is copied to TS.Recent;
238 * otherwise, the TSval is ignored.
240 if (tcp_opts_tstamp (&tc->opt) && tc->tsval_recent
241 && seq_leq (seq, tc->rcv_las) && seq_leq (tc->rcv_las, seq_end))
243 tc->tsval_recent = tc->opt.tsval;
244 tc->tsval_recent_age = tcp_time_now ();
249 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
251 * It first verifies if segment has a wrapped sequence number (PAWS) and then
252 * does the processing associated to the first four steps (ignoring security
253 * and precedence): sequence number, rst bit and syn bit checks.
255 * @return 0 if segments passes validation.
258 tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0,
259 vlib_buffer_t * b0, tcp_header_t * th0, u32 * next0)
261 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
264 tcp_options_parse (th0, &tc0->opt);
266 if (tcp_segment_check_paws (tc0))
268 clib_warning ("paws failed");
269 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
270 vnet_buffer (b0)->tcp.seq_end);
272 /* If it just so happens that a segment updates tsval_recent for a
273 * segment over 24 days old, invalidate tsval_recent. */
274 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
277 /* Age isn't reset until we get a valid tsval (bsd inspired) */
278 tc0->tsval_recent = 0;
279 clib_warning ("paws failed - really old segment. REALLY?");
283 /* Drop after ack if not rst */
286 tcp_make_ack (tc0, b0);
287 *next0 = tcp_next_output (tc0->c_is_ip4);
288 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
294 /* 1st: check sequence number */
295 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
296 vnet_buffer (b0)->tcp.seq_end))
298 /* If our window is 0 and the packet is in sequence, let it pass
299 * through for ack processing. It should be dropped later.*/
300 if (tc0->rcv_wnd == 0
301 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
303 /* TODO Should segment be tagged? */
307 /* If not RST, send dup ack */
310 tcp_make_ack (tc0, b0);
311 *next0 = tcp_next_output (tc0->c_is_ip4);
312 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
318 /* 2nd: check the RST bit */
321 tcp_connection_reset (tc0);
325 /* 3rd: check security and precedence (skip) */
327 /* 4th: check the SYN bit */
330 tcp_send_reset (b0, tc0->c_is_ip4);
334 /* If segment in window, save timestamp */
335 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
336 vnet_buffer (b0)->tcp.seq_end);
342 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
344 /* SND.UNA =< SEG.ACK =< SND.NXT */
345 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
346 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
350 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
352 * Note that although the original article, srtt and rttvar are scaled
353 * to minimize round-off errors, here we don't. Instead, we rely on
354 * better precision time measurements.
356 * TODO support us rtt resolution
359 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
365 err = mrtt - tc->srtt;
366 tc->srtt += err >> 3;
368 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
369 * The increase should be bound */
370 tc->rttvar += ((int) clib_abs (err) - (int) tc->rttvar) >> 2;
374 /* First measurement. */
376 tc->rttvar = mrtt >> 1;
380 /** Update RTT estimate and RTO timer
382 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
383 * timing. Middle boxes are known to fiddle with TCP options so we
384 * should give higher priority to ACK timing.
386 * return 1 if valid rtt 0 otherwise
389 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
394 /* Determine if only rtx bytes are acked. TODO fast retransmit */
395 rtx_acked = tc->rto_boff && (tc->bytes_acked <= tc->snd_mss);
397 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
398 * RTT because they're ambiguous. */
399 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq) && !rtx_acked)
401 mrtt = tcp_time_now () - tc->rtt_ts;
403 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
404 * snd_una, i.e., the left side of the send window:
405 * seq_lt (tc->snd_una, ack). Note: last condition could be dropped, we don't
406 * try to update rtt for dupacks */
407 else if (tcp_opts_tstamp (&tc->opt) && tc->opt.tsecr && tc->bytes_acked)
409 mrtt = tcp_time_now () - tc->opt.tsecr;
412 /* Allow measuring of a new RTT */
415 /* If ACK moves left side of the wnd make sure boff is 0, even if mrtt is
420 /* Ignore dubious measurements */
421 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
424 tcp_estimate_rtt (tc, mrtt);
425 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
431 * Dequeue bytes that have been acked and while at it update RTT estimates.
434 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
436 /* Dequeue the newly ACKed bytes */
437 stream_session_dequeue_drop (&tc->connection, tc->bytes_acked);
439 /* Update rtt and rto */
440 tcp_update_rtt (tc, ack);
444 * Check if dupack as per RFC5681 Sec. 2
446 * This works only if called before updating snd_wnd.
449 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 new_snd_wnd)
451 return ((vnet_buffer (b)->tcp.ack_number == tc->snd_una)
452 && seq_gt (tc->snd_una_max, tc->snd_una)
453 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
454 && (new_snd_wnd == tc->snd_wnd));
458 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
460 sack_scoreboard_hole_t *next, *prev;
462 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
464 next = pool_elt_at_index (sb->holes, hole->next);
465 next->prev = hole->prev;
468 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
470 prev = pool_elt_at_index (sb->holes, hole->prev);
471 prev->next = hole->next;
475 sb->head = hole->next;
478 pool_put (sb->holes, hole);
481 sack_scoreboard_hole_t *
482 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
485 sack_scoreboard_hole_t *hole, *next, *prev;
488 pool_get (sb->holes, hole);
489 memset (hole, 0, sizeof (*hole));
493 hole_index = hole - sb->holes;
495 prev = scoreboard_get_hole (sb, prev_index);
498 hole->prev = prev - sb->holes;
499 hole->next = prev->next;
501 if ((next = scoreboard_next_hole (sb, hole)))
502 next->prev = hole_index;
504 prev->next = hole_index;
508 sb->head = hole_index;
509 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
510 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
517 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
519 sack_scoreboard_t *sb = &tc->sack_sb;
520 sack_block_t *blk, tmp;
521 sack_scoreboard_hole_t *hole, *next_hole, *last_hole, *new_hole;
522 u32 blk_index = 0, old_sacked_bytes, hole_index;
525 sb->last_sacked_bytes = 0;
527 old_sacked_bytes = sb->sacked_bytes;
529 if (!tcp_opts_sack (&tc->opt) && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
532 /* Remove invalid blocks */
534 while (blk < vec_end (tc->opt.sacks))
536 if (seq_lt (blk->start, blk->end)
537 && seq_gt (blk->start, tc->snd_una)
538 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_nxt))
543 vec_del1 (tc->opt.sacks, blk - tc->opt.sacks);
546 /* Add block for cumulative ack */
547 if (seq_gt (ack, tc->snd_una))
549 tmp.start = tc->snd_una;
551 vec_add1 (tc->opt.sacks, tmp);
554 if (vec_len (tc->opt.sacks) == 0)
557 /* Make sure blocks are ordered */
558 for (i = 0; i < vec_len (tc->opt.sacks); i++)
559 for (j = i + 1; j < vec_len (tc->opt.sacks); j++)
560 if (seq_lt (tc->opt.sacks[j].start, tc->opt.sacks[i].start))
562 tmp = tc->opt.sacks[i];
563 tc->opt.sacks[i] = tc->opt.sacks[j];
564 tc->opt.sacks[j] = tmp;
567 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
569 /* If no holes, insert the first that covers all outstanding bytes */
570 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
571 tc->snd_una, tc->snd_una_max);
572 sb->tail = scoreboard_hole_index (sb, last_hole);
576 /* If we have holes but snd_una_max is beyond the last hole, update
578 tmp = tc->opt.sacks[vec_len (tc->opt.sacks) - 1];
579 last_hole = scoreboard_last_hole (sb);
580 if (seq_gt (tc->snd_una_max, sb->max_byte_sacked)
581 && seq_gt (tc->snd_una_max, last_hole->end))
582 last_hole->end = tc->snd_una_max;
585 /* Walk the holes with the SACK blocks */
586 hole = pool_elt_at_index (sb->holes, sb->head);
587 while (hole && blk_index < vec_len (tc->opt.sacks))
589 blk = &tc->opt.sacks[blk_index];
591 if (seq_leq (blk->start, hole->start))
593 /* Block covers hole. Remove hole */
594 if (seq_geq (blk->end, hole->end))
596 next_hole = scoreboard_next_hole (sb, hole);
598 /* Byte accounting */
599 if (seq_leq (hole->end, ack))
601 /* Bytes lost because snd_wnd left edge advances */
602 if (next_hole && seq_leq (next_hole->start, ack))
603 sb->sacked_bytes -= next_hole->start - hole->end;
605 sb->sacked_bytes -= ack - hole->end;
609 sb->sacked_bytes += scoreboard_hole_bytes (hole);
612 /* snd_una needs to be advanced */
613 if (seq_geq (ack, hole->end))
615 if (next_hole && seq_lt (ack, next_hole->start))
616 sb->snd_una_adv = next_hole->start - ack;
618 sb->snd_una_adv = sb->max_byte_sacked - ack;
620 /* all these can be delivered */
621 sb->sacked_bytes -= sb->snd_una_adv;
624 /* About to remove last hole */
625 if (hole == last_hole)
627 sb->tail = hole->prev;
628 last_hole = scoreboard_last_hole (sb);
629 /* keep track of max byte sacked in case the last hole
631 if (seq_gt (hole->end, sb->max_byte_sacked))
632 sb->max_byte_sacked = hole->end;
634 scoreboard_remove_hole (sb, hole);
637 /* Partial 'head' overlap */
640 if (seq_gt (blk->end, hole->start))
642 sb->sacked_bytes += blk->end - hole->start;
643 hole->start = blk->end;
650 /* Hole must be split */
651 if (seq_lt (blk->end, hole->end))
653 sb->sacked_bytes += blk->end - blk->start;
654 hole_index = scoreboard_hole_index (sb, hole);
655 new_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
658 /* Pool might've moved */
659 hole = scoreboard_get_hole (sb, hole_index);
660 hole->end = blk->start;
662 /* New or split of tail */
663 if ((last_hole->end == new_hole->end)
664 || seq_lt (last_hole->end, new_hole->start))
666 last_hole = new_hole;
667 sb->tail = scoreboard_hole_index (sb, new_hole);
671 hole = scoreboard_next_hole (sb, hole);
675 sb->sacked_bytes += hole->end - blk->start;
676 hole->end = blk->start;
677 hole = scoreboard_next_hole (sb, hole);
682 sb->last_sacked_bytes = sb->sacked_bytes + sb->snd_una_adv
688 * If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
689 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
691 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
693 if (seq_lt (tc->snd_wl1, seq)
694 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
696 tc->snd_wnd = snd_wnd;
699 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
701 /* Set probe timer if we just got 0 wnd */
702 if (tc->snd_wnd < tc->snd_mss
703 && !tcp_timer_is_active (tc, TCP_TIMER_PERSIST))
704 tcp_persist_timer_set (tc);
706 tcp_persist_timer_reset (tc);
711 tcp_cc_congestion (tcp_connection_t * tc)
713 tc->snd_congestion = tc->snd_nxt;
714 tc->cc_algo->congestion (tc);
715 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
719 tcp_cc_recover (tcp_connection_t * tc)
721 /* TODO: check if time to recover was small. It might be that RTO popped
725 tc->cc_algo->recovered (tc);
729 tc->snd_nxt = tc->snd_una;
731 tc->cc_algo->rcv_ack (tc);
732 tc->tsecr_last_ack = tc->opt.tsecr;
734 tcp_cong_recovery_off (tc);
736 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
740 tcp_cc_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b)
744 if (tcp_in_fastrecovery (tc))
746 partial_ack = seq_lt (tc->snd_una, tc->snd_congestion);
749 /* Clear retransmitted bytes. */
754 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
756 /* Clear retransmitted bytes. XXX should we clear all? */
759 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
761 /* In case snd_nxt is still in the past and output tries to
762 * shove some new bytes */
763 tc->snd_nxt = tc->snd_una_max;
765 /* XXX need proper RFC6675 support */
766 if (tc->sack_sb.last_sacked_bytes && !tcp_in_recovery (tc))
768 tcp_fast_retransmit (tc);
772 /* Retransmit first unacked segment */
773 tcp_retransmit_first_unacked (tc);
779 tc->cc_algo->rcv_ack (tc);
780 tc->tsecr_last_ack = tc->opt.tsecr;
782 if (tcp_in_recovery (tc))
784 tc->rtx_bytes -= clib_min (tc->bytes_acked, tc->rtx_bytes);
785 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
786 if (seq_geq (tc->snd_una, tc->snd_congestion))
787 tcp_recovery_off (tc);
793 tcp_cc_rcv_dupack (tcp_connection_t * tc, u32 ack)
795 // ASSERT (seq_geq(tc->snd_una, ack));
798 if (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
800 /* RFC6582 NewReno heuristic to avoid multiple fast retransmits */
801 if (tc->opt.tsecr != tc->tsecr_last_ack)
807 tcp_fastrecovery_on (tc);
809 /* Handle congestion and dupack */
810 tcp_cc_congestion (tc);
811 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
813 tcp_fast_retransmit (tc);
815 /* Post retransmit update cwnd to ssthresh and account for the
816 * three segments that have left the network and should've been
817 * buffered at the receiver */
818 tc->cwnd = tc->ssthresh + TCP_DUPACK_THRESHOLD * tc->snd_mss;
820 else if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD)
822 ASSERT (tcp_in_fastrecovery (tc));
824 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
829 tcp_cc_init (tcp_connection_t * tc)
831 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
832 tc->cc_algo->init (tc);
836 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
837 tcp_header_t * th, u32 * next, u32 * error)
841 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
842 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt))
844 /* If we have outstanding data and this is within the window, accept it,
845 * probably retransmit has timed out. Otherwise ACK segment and then
847 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
849 tcp_make_ack (tc, b);
850 *next = tcp_next_output (tc->c_is_ip4);
851 *error = TCP_ERROR_ACK_INVALID;
852 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
853 vnet_buffer (b)->tcp.ack_number);
857 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
858 vnet_buffer (b)->tcp.ack_number);
860 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
861 *error = TCP_ERROR_ACK_FUTURE;
864 /* If old ACK, probably it's an old dupack */
865 if (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
867 *error = TCP_ERROR_ACK_OLD;
868 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
869 vnet_buffer (b)->tcp.ack_number);
870 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
872 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
873 tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number);
879 if (tcp_opts_sack_permitted (&tc->opt))
880 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
882 new_snd_wnd = clib_net_to_host_u16 (th->window) << tc->snd_wscale;
884 if (tcp_ack_is_dupack (tc, b, new_snd_wnd))
886 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
887 tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number);
888 *error = TCP_ERROR_ACK_DUP;
896 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
897 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
899 /* Dequeue ACKed data and update RTT */
900 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
901 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
902 vnet_buffer (b)->tcp.ack_number, new_snd_wnd);
904 /* If some of our sent bytes have been acked, update cc and retransmit
908 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
910 /* Updates congestion control (slow start/congestion avoidance) */
911 tcp_cc_rcv_ack (tc, b);
913 /* If everything has been acked, stop retransmit timer
914 * otherwise update. */
915 if (tc->snd_una == tc->snd_una_max)
916 tcp_retransmit_timer_reset (tc);
918 tcp_retransmit_timer_update (tc);
925 * Build SACK list as per RFC2018.
927 * Makes sure the first block contains the segment that generated the current
928 * ACK and the following ones are the ones most recently reported in SACK
931 * @param tc TCP connection for which the SACK list is updated
932 * @param start Start sequence number of the newest SACK block
933 * @param end End sequence of the newest SACK block
936 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
938 sack_block_t *new_list = 0, *block = 0;
941 /* If the first segment is ooo add it to the list. Last write might've moved
942 * rcv_nxt over the first segment. */
943 if (seq_lt (tc->rcv_nxt, start))
945 vec_add2 (new_list, block, 1);
946 block->start = start;
950 /* Find the blocks still worth keeping. */
951 for (i = 0; i < vec_len (tc->snd_sacks); i++)
953 /* Discard if rcv_nxt advanced beyond current block */
954 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
957 /* Merge or drop if segment overlapped by the new segment */
958 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
959 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
961 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
962 new_list[0].start = tc->snd_sacks[i].start;
963 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
964 new_list[0].end = tc->snd_sacks[i].end;
968 /* Save to new SACK list if we have space. */
969 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
971 vec_add1 (new_list, tc->snd_sacks[i]);
975 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
977 /* Replace old vector with new one */
978 vec_free (tc->snd_sacks);
979 tc->snd_sacks = new_list;
982 /** Enqueue data for delivery to application */
984 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
989 /* Pure ACK. Update rcv_nxt and be done. */
990 if (PREDICT_FALSE (data_len == 0))
992 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
993 return TCP_ERROR_PURE_ACK;
996 written = stream_session_enqueue_data (&tc->connection, b, 0,
997 1 /* queue event */ , 1);
999 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1001 /* Update rcv_nxt */
1002 if (PREDICT_TRUE (written == data_len))
1004 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
1006 /* If more data written than expected, account for out-of-order bytes. */
1007 else if (written > data_len)
1009 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end + written - data_len;
1011 /* Send ACK confirming the update */
1012 tc->flags |= TCP_CONN_SNDACK;
1014 else if (written > 0)
1016 /* We've written something but FIFO is probably full now */
1017 tc->rcv_nxt += written;
1019 /* Depending on how fast the app is, all remaining buffers in burst will
1020 * not be enqueued. Inform peer */
1021 tc->flags |= TCP_CONN_SNDACK;
1023 return TCP_ERROR_PARTIALLY_ENQUEUED;
1027 tc->flags |= TCP_CONN_SNDACK;
1028 return TCP_ERROR_FIFO_FULL;
1031 /* Update SACK list if need be */
1032 if (tcp_opts_sack_permitted (&tc->opt))
1034 /* Remove SACK blocks that have been delivered */
1035 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1038 return TCP_ERROR_ENQUEUED;
1041 /** Enqueue out-of-order data */
1043 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1046 stream_session_t *s0;
1049 /* Pure ACK. Do nothing */
1050 if (PREDICT_FALSE (data_len == 0))
1052 return TCP_ERROR_PURE_ACK;
1055 /* Enqueue out-of-order data with absolute offset */
1056 rv = stream_session_enqueue_data (&tc->connection, b,
1057 vnet_buffer (b)->tcp.seq_number,
1058 0 /* queue event */ , 0);
1060 /* Nothing written */
1063 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1064 return TCP_ERROR_FIFO_FULL;
1067 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1069 /* Update SACK list if in use */
1070 if (tcp_opts_sack_permitted (&tc->opt))
1072 ooo_segment_t *newest;
1075 s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
1077 /* Get the newest segment from the fifo */
1078 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1079 start = ooo_segment_offset (s0->server_rx_fifo, newest);
1080 end = ooo_segment_end_offset (s0->server_rx_fifo, newest);
1082 tcp_update_sack_list (tc, start, end);
1085 return TCP_ERROR_ENQUEUED;
1089 * Check if ACK could be delayed. If ack can be delayed, it should return
1090 * true for a full frame. If we're always acking return 0.
1093 tcp_can_delack (tcp_connection_t * tc)
1095 /* Send ack if ... */
1097 /* just sent a rcv wnd 0 */
1098 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1099 /* constrained to send ack */
1100 || (tc->flags & TCP_CONN_SNDACK) != 0
1101 /* we're almost out of tx wnd */
1102 || tcp_available_snd_space (tc) < 2 * tc->snd_mss)
1109 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1110 u16 n_data_bytes, u32 * next0)
1114 /* Handle out-of-order data */
1115 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1117 /* Old sequence numbers allowed through because they overlapped
1120 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1122 error = TCP_ERROR_SEGMENT_OLD;
1123 *next0 = TCP_NEXT_DROP;
1127 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1129 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1130 * cwnd on remote peer when congested 2) acks leaving should have the
1131 * latest rcv_wnd since the burst may eaten up all of it, so only the
1132 * old ones could be filtered.
1135 /* RFC2581: Send DUPACK for fast retransmit */
1136 tcp_make_ack (tc, b);
1137 *next0 = tcp_next_output (tc->c_is_ip4);
1139 /* Mark as DUPACK. We may filter these in output if
1140 * the burst fills the holes. */
1142 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1144 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1148 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1149 * segments can be enqueued after fifo tail offset changes. */
1150 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1152 if (n_data_bytes == 0)
1154 *next0 = TCP_NEXT_DROP;
1158 /* Check if ACK can be delayed */
1159 if (tcp_can_delack (tc))
1161 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1162 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1166 *next0 = tcp_next_output (tc->c_is_ip4);
1167 tcp_make_ack (tc, b);
1175 tcp_header_t tcp_header;
1176 tcp_connection_t tcp_connection;
1180 format_tcp_rx_trace (u8 * s, va_list * args)
1182 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1183 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1184 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1185 uword indent = format_get_indent (s);
1187 s = format (s, "%U\n%U%U",
1188 format_tcp_header, &t->tcp_header, 128,
1189 format_white_space, indent,
1190 format_tcp_connection_verbose, &t->tcp_connection);
1196 format_tcp_rx_trace_short (u8 * s, va_list * args)
1198 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1199 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1200 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1202 s = format (s, "%d -> %d (%U)",
1203 clib_net_to_host_u16 (t->tcp_header.src_port),
1204 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1205 &t->tcp_connection.state);
1211 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1212 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1216 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1220 th0 = tcp_buffer_hdr (b0);
1222 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1226 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1228 if (PREDICT_TRUE (!val))
1232 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1234 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1238 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1239 vlib_frame_t * from_frame, int is_ip4)
1241 u32 n_left_from, next_index, *from, *to_next;
1242 u32 my_thread_index = vm->thread_index, errors = 0;
1243 tcp_main_t *tm = vnet_get_tcp_main ();
1246 from = vlib_frame_vector_args (from_frame);
1247 n_left_from = from_frame->n_vectors;
1249 next_index = node->cached_next_index;
1251 while (n_left_from > 0)
1255 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1257 while (n_left_from > 0 && n_left_to_next > 0)
1261 tcp_header_t *th0 = 0;
1262 tcp_connection_t *tc0;
1263 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1270 n_left_to_next -= 1;
1272 b0 = vlib_get_buffer (vm, bi0);
1273 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1276 if (PREDICT_FALSE (tc0 == 0))
1278 error0 = TCP_ERROR_INVALID_CONNECTION;
1282 th0 = tcp_buffer_hdr (b0);
1284 is_fin = (th0->flags & TCP_FLAG_FIN) != 0;
1286 /* SYNs, FINs and data consume sequence numbers */
1287 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1288 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1290 /* TODO header prediction fast path */
1292 /* 1-4: check SEQ, RST, SYN */
1293 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1295 error0 = TCP_ERROR_SEGMENT_INVALID;
1296 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1297 vnet_buffer (b0)->tcp.seq_number,
1298 vnet_buffer (b0)->tcp.seq_end);
1302 /* 5: check the ACK field */
1303 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1308 /* 6: check the URG bit TODO */
1310 /* 7: process the segment text */
1312 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1313 error0 = tcp_segment_rcv (tm, tc0, b0,
1314 vnet_buffer (b0)->tcp.data_len, &next0);
1316 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1317 * dangling reference. */
1319 /* 8: check the FIN bit */
1322 /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
1323 * wait for session to call close. To avoid lingering
1324 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1325 tc0->state = TCP_STATE_CLOSE_WAIT;
1326 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1327 stream_session_disconnect_notify (&tc0->connection);
1328 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1332 b0->error = node->errors[error0];
1333 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1335 tcp_rx_trace_t *t0 =
1336 vlib_add_trace (vm, node, b0, sizeof (*t0));
1337 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1340 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1341 n_left_to_next, bi0, next0);
1344 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1347 errors = session_manager_flush_enqueue_events (my_thread_index);
1348 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1350 return from_frame->n_vectors;
1354 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1355 vlib_frame_t * from_frame)
1357 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1361 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1362 vlib_frame_t * from_frame)
1364 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1368 VLIB_REGISTER_NODE (tcp4_established_node) =
1370 .function = tcp4_established,
1371 .name = "tcp4-established",
1372 /* Takes a vector of packets. */
1373 .vector_size = sizeof (u32),
1374 .n_errors = TCP_N_ERROR,
1375 .error_strings = tcp_error_strings,
1376 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1379 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1380 foreach_tcp_state_next
1383 .format_trace = format_tcp_rx_trace_short,
1387 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1390 VLIB_REGISTER_NODE (tcp6_established_node) =
1392 .function = tcp6_established,
1393 .name = "tcp6-established",
1394 /* Takes a vector of packets. */
1395 .vector_size = sizeof (u32),
1396 .n_errors = TCP_N_ERROR,
1397 .error_strings = tcp_error_strings,
1398 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1401 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1402 foreach_tcp_state_next
1405 .format_trace = format_tcp_rx_trace_short,
1410 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1412 vlib_node_registration_t tcp4_syn_sent_node;
1413 vlib_node_registration_t tcp6_syn_sent_node;
1416 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1417 vlib_frame_t * from_frame, int is_ip4)
1419 tcp_main_t *tm = vnet_get_tcp_main ();
1420 u32 n_left_from, next_index, *from, *to_next;
1421 u32 my_thread_index = vm->thread_index, errors = 0;
1422 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
1424 from = vlib_frame_vector_args (from_frame);
1425 n_left_from = from_frame->n_vectors;
1427 next_index = node->cached_next_index;
1429 while (n_left_from > 0)
1433 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1435 while (n_left_from > 0 && n_left_to_next > 0)
1437 u32 bi0, ack0, seq0;
1440 tcp_header_t *tcp0 = 0;
1441 tcp_connection_t *tc0;
1442 tcp_connection_t *new_tc0;
1443 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1450 n_left_to_next -= 1;
1452 b0 = vlib_get_buffer (vm, bi0);
1454 tcp_half_open_connection_get (vnet_buffer (b0)->
1455 tcp.connection_index);
1457 ack0 = vnet_buffer (b0)->tcp.ack_number;
1458 seq0 = vnet_buffer (b0)->tcp.seq_number;
1459 tcp0 = tcp_buffer_hdr (b0);
1462 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1465 /* SYNs, FINs and data consume sequence numbers */
1466 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1467 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
1470 * 1. check the ACK bit
1474 * If the ACK bit is set
1475 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
1476 * the RST bit is set, if so drop the segment and return)
1477 * <SEQ=SEG.ACK><CTL=RST>
1478 * and discard the segment. Return.
1479 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
1483 if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt)
1485 if (!tcp_rst (tcp0))
1486 tcp_send_reset (b0, is_ip4);
1491 /* Make sure ACK is valid */
1492 if (tc0->snd_una > ack0)
1497 * 2. check the RST bit
1502 /* If ACK is acceptable, signal client that peer is not
1503 * willing to accept connection and drop connection*/
1506 stream_session_connect_notify (&tc0->connection, sst,
1508 tcp_connection_cleanup (tc0);
1514 * 3. check the security and precedence (skipped)
1518 * 4. check the SYN bit
1521 /* No SYN flag. Drop. */
1522 if (!tcp_syn (tcp0))
1525 /* Stop connection establishment and retransmit timers */
1526 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
1527 tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT_SYN);
1529 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
1530 * current thread pool. */
1531 pool_get (tm->connections[my_thread_index], new_tc0);
1532 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
1534 new_tc0->c_thread_index = my_thread_index;
1536 /* Cleanup half-open connection XXX lock */
1537 pool_put (tm->half_open_connections, tc0);
1539 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
1540 new_tc0->irs = seq0;
1543 tcp_options_parse (tcp0, &new_tc0->opt);
1545 if (tcp_opts_tstamp (&new_tc0->opt))
1547 new_tc0->tsval_recent = new_tc0->opt.tsval;
1548 new_tc0->tsval_recent_age = tcp_time_now ();
1551 if (tcp_opts_wscale (&new_tc0->opt))
1552 new_tc0->snd_wscale = new_tc0->opt.wscale;
1555 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
1556 new_tc0->snd_wl1 = seq0;
1557 new_tc0->snd_wl2 = ack0;
1559 tcp_connection_init_vars (new_tc0);
1561 /* SYN-ACK: See if we can switch to ESTABLISHED state */
1564 /* Our SYN is ACKed: we have iss < ack = snd_una */
1566 /* TODO Dequeue acknowledged segments if we support Fast Open */
1567 new_tc0->snd_una = ack0;
1568 new_tc0->state = TCP_STATE_ESTABLISHED;
1570 /* Make sure las is initialized for the wnd computation */
1571 new_tc0->rcv_las = new_tc0->rcv_nxt;
1573 /* Notify app that we have connection */
1574 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1576 stream_session_init_fifos_pointers (&new_tc0->connection,
1579 /* Make sure after data segment processing ACK is sent */
1580 new_tc0->flags |= TCP_CONN_SNDACK;
1582 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
1585 new_tc0->state = TCP_STATE_SYN_RCVD;
1587 /* Notify app that we have connection */
1588 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1589 stream_session_init_fifos_pointers (&new_tc0->connection,
1592 tcp_make_synack (new_tc0, b0);
1593 next0 = tcp_next_output (is_ip4);
1598 /* Read data, if any */
1599 if (vnet_buffer (b0)->tcp.data_len)
1601 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1602 error0 = tcp_segment_rcv (tm, new_tc0, b0,
1603 vnet_buffer (b0)->tcp.data_len,
1605 if (error0 == TCP_ERROR_PURE_ACK)
1606 error0 = TCP_ERROR_SYN_ACKS_RCVD;
1610 tcp_make_ack (new_tc0, b0);
1611 next0 = tcp_next_output (new_tc0->c_is_ip4);
1616 b0->error = error0 ? node->errors[error0] : 0;
1617 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1619 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1620 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
1621 clib_memcpy (&t0->tcp_connection, tc0,
1622 sizeof (t0->tcp_connection));
1625 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1626 n_left_to_next, bi0, next0);
1629 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1632 errors = session_manager_flush_enqueue_events (my_thread_index);
1636 vlib_node_increment_counter (vm, tcp4_established_node.index,
1637 TCP_ERROR_EVENT_FIFO_FULL, errors);
1639 vlib_node_increment_counter (vm, tcp6_established_node.index,
1640 TCP_ERROR_EVENT_FIFO_FULL, errors);
1643 return from_frame->n_vectors;
1647 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
1648 vlib_frame_t * from_frame)
1650 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1654 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
1655 vlib_frame_t * from_frame)
1657 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1661 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
1663 .function = tcp4_syn_sent,
1664 .name = "tcp4-syn-sent",
1665 /* Takes a vector of packets. */
1666 .vector_size = sizeof (u32),
1667 .n_errors = TCP_N_ERROR,
1668 .error_strings = tcp_error_strings,
1669 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1672 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1673 foreach_tcp_state_next
1676 .format_trace = format_tcp_rx_trace_short,
1680 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
1683 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
1685 .function = tcp6_syn_sent_rcv,
1686 .name = "tcp6-syn-sent",
1687 /* Takes a vector of packets. */
1688 .vector_size = sizeof (u32),
1689 .n_errors = TCP_N_ERROR,
1690 .error_strings = tcp_error_strings,
1691 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1694 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1695 foreach_tcp_state_next
1698 .format_trace = format_tcp_rx_trace_short,
1702 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
1704 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
1705 * as per RFC793 p. 64
1708 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1709 vlib_frame_t * from_frame, int is_ip4)
1711 tcp_main_t *tm = vnet_get_tcp_main ();
1712 u32 n_left_from, next_index, *from, *to_next;
1713 u32 my_thread_index = vm->thread_index, errors = 0;
1715 from = vlib_frame_vector_args (from_frame);
1716 n_left_from = from_frame->n_vectors;
1718 next_index = node->cached_next_index;
1720 while (n_left_from > 0)
1724 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1726 while (n_left_from > 0 && n_left_to_next > 0)
1730 tcp_header_t *tcp0 = 0;
1731 tcp_connection_t *tc0;
1732 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1739 n_left_to_next -= 1;
1741 b0 = vlib_get_buffer (vm, bi0);
1742 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1744 if (PREDICT_FALSE (tc0 == 0))
1746 error0 = TCP_ERROR_INVALID_CONNECTION;
1750 tcp0 = tcp_buffer_hdr (b0);
1752 /* SYNs, FINs and data consume sequence numbers */
1753 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1754 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0)
1755 + vnet_buffer (b0)->tcp.data_len;
1758 * Special treatment for CLOSED
1762 case TCP_STATE_CLOSED:
1768 * For all other states (except LISTEN)
1771 /* 1-4: check SEQ, RST, SYN */
1773 (tcp_segment_validate (vm, tc0, b0, tcp0, &next0)))
1775 error0 = TCP_ERROR_SEGMENT_INVALID;
1779 /* 5: check the ACK field */
1782 case TCP_STATE_SYN_RCVD:
1784 * If the segment acknowledgment is not acceptable, form a
1786 * <SEQ=SEG.ACK><CTL=RST>
1789 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
1791 tcp_send_reset (b0, is_ip4);
1795 /* Update rtt and rto */
1796 tc0->bytes_acked = 1;
1797 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
1799 /* Switch state to ESTABLISHED */
1800 tc0->state = TCP_STATE_ESTABLISHED;
1802 /* Initialize session variables */
1803 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
1804 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
1806 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
1807 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
1809 /* Shoulder tap the server */
1810 stream_session_accept_notify (&tc0->connection);
1812 /* Reset SYN-ACK retransmit timer */
1813 tcp_retransmit_timer_reset (tc0);
1815 case TCP_STATE_ESTABLISHED:
1816 /* We can get packets in established state here because they
1817 * were enqueued before state change */
1818 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1822 case TCP_STATE_FIN_WAIT_1:
1823 /* In addition to the processing for the ESTABLISHED state, if
1824 * our FIN is now acknowledged then enter FIN-WAIT-2 and
1825 * continue processing in that state. */
1826 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1829 /* If FIN is ACKed */
1830 if (tc0->snd_una == tc0->snd_una_max)
1832 tc0->state = TCP_STATE_FIN_WAIT_2;
1833 /* Stop all timers, 2MSL will be set lower */
1834 tcp_connection_timers_reset (tc0);
1837 case TCP_STATE_FIN_WAIT_2:
1838 /* In addition to the processing for the ESTABLISHED state, if
1839 * the retransmission queue is empty, the user's CLOSE can be
1840 * acknowledged ("ok") but do not delete the TCB. */
1841 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1843 /* check if rtx queue is empty and ack CLOSE TODO */
1845 case TCP_STATE_CLOSE_WAIT:
1846 /* Do the same processing as for the ESTABLISHED state. */
1847 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1850 case TCP_STATE_CLOSING:
1851 /* In addition to the processing for the ESTABLISHED state, if
1852 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
1853 * otherwise ignore the segment. */
1854 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1857 /* XXX test that send queue empty */
1858 tc0->state = TCP_STATE_TIME_WAIT;
1862 case TCP_STATE_LAST_ACK:
1863 /* The only thing that can arrive in this state is an
1864 * acknowledgment of our FIN. If our FIN is now acknowledged,
1865 * delete the TCB, enter the CLOSED state, and return. */
1867 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
1870 tc0->state = TCP_STATE_CLOSED;
1872 /* Don't delete the connection/session yet. Instead, wait a
1873 * reasonable amount of time until the pipes are cleared. In
1874 * particular, this makes sure that we won't have dead sessions
1875 * when processing events on the tx path */
1876 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
1878 /* Stop retransmit */
1879 tcp_retransmit_timer_reset (tc0);
1884 case TCP_STATE_TIME_WAIT:
1885 /* The only thing that can arrive in this state is a
1886 * retransmission of the remote FIN. Acknowledge it, and restart
1887 * the 2 MSL timeout. */
1896 /* 6: check the URG bit TODO */
1898 /* 7: process the segment text */
1901 case TCP_STATE_ESTABLISHED:
1902 case TCP_STATE_FIN_WAIT_1:
1903 case TCP_STATE_FIN_WAIT_2:
1904 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1905 error0 = tcp_segment_rcv (tm, tc0, b0,
1906 vnet_buffer (b0)->tcp.data_len,
1909 case TCP_STATE_CLOSE_WAIT:
1910 case TCP_STATE_CLOSING:
1911 case TCP_STATE_LAST_ACK:
1912 case TCP_STATE_TIME_WAIT:
1913 /* This should not occur, since a FIN has been received from the
1914 * remote side. Ignore the segment text. */
1918 /* 8: check the FIN bit */
1919 if (!tcp_fin (tcp0))
1924 case TCP_STATE_ESTABLISHED:
1925 case TCP_STATE_SYN_RCVD:
1926 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
1927 tcp_connection_timers_reset (tc0);
1928 tcp_make_fin (tc0, b0);
1929 next0 = tcp_next_output (tc0->c_is_ip4);
1930 stream_session_disconnect_notify (&tc0->connection);
1931 tc0->state = TCP_STATE_CLOSE_WAIT;
1933 case TCP_STATE_CLOSE_WAIT:
1934 case TCP_STATE_CLOSING:
1935 case TCP_STATE_LAST_ACK:
1938 case TCP_STATE_FIN_WAIT_1:
1939 tc0->state = TCP_STATE_TIME_WAIT;
1940 tcp_connection_timers_reset (tc0);
1941 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
1943 case TCP_STATE_FIN_WAIT_2:
1944 /* Got FIN, send ACK! */
1945 tc0->state = TCP_STATE_TIME_WAIT;
1946 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1947 tcp_make_ack (tc0, b0);
1948 next0 = tcp_next_output (is_ip4);
1950 case TCP_STATE_TIME_WAIT:
1951 /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
1954 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
1957 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1960 b0->error = error0 ? node->errors[error0] : 0;
1962 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1964 tcp_rx_trace_t *t0 =
1965 vlib_add_trace (vm, node, b0, sizeof (*t0));
1966 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
1969 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1970 n_left_to_next, bi0, next0);
1973 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1976 errors = session_manager_flush_enqueue_events (my_thread_index);
1980 vlib_node_increment_counter (vm, tcp4_established_node.index,
1981 TCP_ERROR_EVENT_FIFO_FULL, errors);
1983 vlib_node_increment_counter (vm, tcp6_established_node.index,
1984 TCP_ERROR_EVENT_FIFO_FULL, errors);
1987 return from_frame->n_vectors;
1991 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
1992 vlib_frame_t * from_frame)
1994 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1998 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
1999 vlib_frame_t * from_frame)
2001 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2005 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2007 .function = tcp4_rcv_process,
2008 .name = "tcp4-rcv-process",
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_RCV_PROCESS_N_NEXT,
2016 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2017 foreach_tcp_state_next
2020 .format_trace = format_tcp_rx_trace_short,
2024 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2027 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2029 .function = tcp6_rcv_process,
2030 .name = "tcp6-rcv-process",
2031 /* Takes a vector of packets. */
2032 .vector_size = sizeof (u32),
2033 .n_errors = TCP_N_ERROR,
2034 .error_strings = tcp_error_strings,
2035 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2038 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2039 foreach_tcp_state_next
2042 .format_trace = format_tcp_rx_trace_short,
2046 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2048 vlib_node_registration_t tcp4_listen_node;
2049 vlib_node_registration_t tcp6_listen_node;
2052 * LISTEN state processing as per RFC 793 p. 65
2055 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2056 vlib_frame_t * from_frame, int is_ip4)
2058 u32 n_left_from, next_index, *from, *to_next;
2059 u32 my_thread_index = vm->thread_index;
2060 tcp_main_t *tm = vnet_get_tcp_main ();
2061 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
2063 from = vlib_frame_vector_args (from_frame);
2064 n_left_from = from_frame->n_vectors;
2066 next_index = node->cached_next_index;
2068 while (n_left_from > 0)
2072 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2074 while (n_left_from > 0 && n_left_to_next > 0)
2079 tcp_header_t *th0 = 0;
2080 tcp_connection_t *lc0;
2083 tcp_connection_t *child0;
2084 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2091 n_left_to_next -= 1;
2093 b0 = vlib_get_buffer (vm, bi0);
2094 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2098 ip40 = vlib_buffer_get_current (b0);
2099 th0 = ip4_next_header (ip40);
2103 ip60 = vlib_buffer_get_current (b0);
2104 th0 = ip6_next_header (ip60);
2107 /* Create child session. For syn-flood protection use filter */
2109 /* 1. first check for an RST */
2113 /* 2. second check for an ACK */
2116 tcp_send_reset (b0, is_ip4);
2120 /* 3. check for a SYN (did that already) */
2122 /* Create child session and send SYN-ACK */
2123 pool_get (tm->connections[my_thread_index], child0);
2124 memset (child0, 0, sizeof (*child0));
2126 child0->c_c_index = child0 - tm->connections[my_thread_index];
2127 child0->c_lcl_port = lc0->c_lcl_port;
2128 child0->c_rmt_port = th0->src_port;
2129 child0->c_is_ip4 = is_ip4;
2130 child0->c_thread_index = my_thread_index;
2134 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2135 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2139 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2140 sizeof (ip6_address_t));
2141 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2142 sizeof (ip6_address_t));
2145 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2148 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2152 tcp_options_parse (th0, &child0->opt);
2154 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2155 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2156 child0->rcv_las = child0->rcv_nxt;
2157 child0->state = TCP_STATE_SYN_RCVD;
2159 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2160 * segments are used to initialize PAWS. */
2161 if (tcp_opts_tstamp (&child0->opt))
2163 child0->tsval_recent = child0->opt.tsval;
2164 child0->tsval_recent_age = tcp_time_now ();
2167 if (tcp_opts_wscale (&child0->opt))
2168 child0->snd_wscale = child0->opt.wscale;
2171 child0->snd_wnd = clib_net_to_host_u16 (th0->window);
2172 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2173 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2175 tcp_connection_init_vars (child0);
2177 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0);
2179 /* Reuse buffer to make syn-ack and send */
2180 tcp_make_synack (child0, b0);
2181 next0 = tcp_next_output (is_ip4);
2183 /* Init fifo pointers after we have iss */
2184 stream_session_init_fifos_pointers (&child0->connection,
2188 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2190 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2191 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2192 clib_memcpy (&t0->tcp_connection, lc0,
2193 sizeof (t0->tcp_connection));
2196 b0->error = node->errors[error0];
2198 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2199 n_left_to_next, bi0, next0);
2202 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2204 return from_frame->n_vectors;
2208 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2209 vlib_frame_t * from_frame)
2211 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2215 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2216 vlib_frame_t * from_frame)
2218 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2222 VLIB_REGISTER_NODE (tcp4_listen_node) =
2224 .function = tcp4_listen,
2225 .name = "tcp4-listen",
2226 /* Takes a vector of packets. */
2227 .vector_size = sizeof (u32),
2228 .n_errors = TCP_N_ERROR,
2229 .error_strings = tcp_error_strings,
2230 .n_next_nodes = TCP_LISTEN_N_NEXT,
2233 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2234 foreach_tcp_state_next
2237 .format_trace = format_tcp_rx_trace_short,
2241 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2244 VLIB_REGISTER_NODE (tcp6_listen_node) =
2246 .function = tcp6_listen,
2247 .name = "tcp6-listen",
2248 /* Takes a vector of packets. */
2249 .vector_size = sizeof (u32),
2250 .n_errors = TCP_N_ERROR,
2251 .error_strings = tcp_error_strings,
2252 .n_next_nodes = TCP_LISTEN_N_NEXT,
2255 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2256 foreach_tcp_state_next
2259 .format_trace = format_tcp_rx_trace_short,
2263 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2265 vlib_node_registration_t tcp4_input_node;
2266 vlib_node_registration_t tcp6_input_node;
2268 typedef enum _tcp_input_next
2270 TCP_INPUT_NEXT_DROP,
2271 TCP_INPUT_NEXT_LISTEN,
2272 TCP_INPUT_NEXT_RCV_PROCESS,
2273 TCP_INPUT_NEXT_SYN_SENT,
2274 TCP_INPUT_NEXT_ESTABLISHED,
2275 TCP_INPUT_NEXT_RESET,
2279 #define foreach_tcp4_input_next \
2280 _ (DROP, "error-drop") \
2281 _ (LISTEN, "tcp4-listen") \
2282 _ (RCV_PROCESS, "tcp4-rcv-process") \
2283 _ (SYN_SENT, "tcp4-syn-sent") \
2284 _ (ESTABLISHED, "tcp4-established") \
2285 _ (RESET, "tcp4-reset")
2287 #define foreach_tcp6_input_next \
2288 _ (DROP, "error-drop") \
2289 _ (LISTEN, "tcp6-listen") \
2290 _ (RCV_PROCESS, "tcp6-rcv-process") \
2291 _ (SYN_SENT, "tcp6-syn-sent") \
2292 _ (ESTABLISHED, "tcp6-established") \
2293 _ (RESET, "tcp6-reset")
2295 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2298 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2299 vlib_frame_t * from_frame, int is_ip4)
2301 u32 n_left_from, next_index, *from, *to_next;
2302 u32 my_thread_index = vm->thread_index;
2303 tcp_main_t *tm = vnet_get_tcp_main ();
2305 from = vlib_frame_vector_args (from_frame);
2306 n_left_from = from_frame->n_vectors;
2308 next_index = node->cached_next_index;
2310 while (n_left_from > 0)
2314 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2316 while (n_left_from > 0 && n_left_to_next > 0)
2318 int n_advance_bytes0, n_data_bytes0;
2321 tcp_header_t *tcp0 = 0;
2322 tcp_connection_t *tc0;
2325 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2333 n_left_to_next -= 1;
2335 b0 = vlib_get_buffer (vm, bi0);
2336 vnet_buffer (b0)->tcp.flags = 0;
2338 /* Checksum computed by ipx_local no need to compute again */
2342 ip40 = vlib_buffer_get_current (b0);
2343 tcp0 = ip4_next_header (ip40);
2344 n_advance_bytes0 = (ip4_header_bytes (ip40)
2345 + tcp_header_bytes (tcp0));
2346 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2349 /* lookup session */
2351 (tcp_connection_t *)
2352 stream_session_lookup_transport4 (&ip40->dst_address,
2356 SESSION_TYPE_IP4_TCP,
2361 ip60 = vlib_buffer_get_current (b0);
2362 tcp0 = ip6_next_header (ip60);
2363 n_advance_bytes0 = tcp_header_bytes (tcp0);
2364 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2366 n_advance_bytes0 += sizeof (ip60[0]);
2369 (tcp_connection_t *)
2370 stream_session_lookup_transport6 (&ip60->src_address,
2374 SESSION_TYPE_IP6_TCP,
2379 if (PREDICT_FALSE (n_advance_bytes0 < 0))
2381 error0 = TCP_ERROR_LENGTH;
2385 /* Session exists */
2386 if (PREDICT_TRUE (0 != tc0))
2388 /* Save connection index */
2389 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2390 vnet_buffer (b0)->tcp.seq_number =
2391 clib_net_to_host_u32 (tcp0->seq_number);
2392 vnet_buffer (b0)->tcp.ack_number =
2393 clib_net_to_host_u32 (tcp0->ack_number);
2395 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
2396 - (u8 *) vlib_buffer_get_current (b0);
2397 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
2398 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
2400 flags0 = tcp0->flags & filter_flags;
2401 next0 = tm->dispatch_table[tc0->state][flags0].next;
2402 error0 = tm->dispatch_table[tc0->state][flags0].error;
2404 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH))
2406 tcp_state_t state0 = tc0->state;
2407 /* Overload tcp flags to store state */
2408 vnet_buffer (b0)->tcp.flags = tc0->state;
2409 clib_warning ("disp error state %U flags %U",
2410 format_tcp_state, &state0,
2411 format_tcp_flags, (int) flags0);
2417 next0 = TCP_INPUT_NEXT_RESET;
2418 error0 = TCP_ERROR_NO_LISTENER;
2422 b0->error = error0 ? node->errors[error0] : 0;
2424 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2426 tcp_rx_trace_t *t0 =
2427 vlib_add_trace (vm, node, b0, sizeof (*t0));
2428 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2431 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2432 n_left_to_next, bi0, next0);
2435 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2438 return from_frame->n_vectors;
2442 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2443 vlib_frame_t * from_frame)
2445 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2449 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2450 vlib_frame_t * from_frame)
2452 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2456 VLIB_REGISTER_NODE (tcp4_input_node) =
2458 .function = tcp4_input,
2459 .name = "tcp4-input",
2460 /* Takes a vector of packets. */
2461 .vector_size = sizeof (u32),
2462 .n_errors = TCP_N_ERROR,
2463 .error_strings = tcp_error_strings,
2464 .n_next_nodes = TCP_INPUT_N_NEXT,
2467 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2468 foreach_tcp4_input_next
2471 .format_buffer = format_tcp_header,
2472 .format_trace = format_tcp_rx_trace,
2476 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
2479 VLIB_REGISTER_NODE (tcp6_input_node) =
2481 .function = tcp6_input,
2482 .name = "tcp6-input",
2483 /* Takes a vector of packets. */
2484 .vector_size = sizeof (u32),
2485 .n_errors = TCP_N_ERROR,
2486 .error_strings = tcp_error_strings,
2487 .n_next_nodes = TCP_INPUT_N_NEXT,
2490 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2491 foreach_tcp6_input_next
2494 .format_buffer = format_tcp_header,
2495 .format_trace = format_tcp_rx_trace,
2499 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
2502 tcp_dispatch_table_init (tcp_main_t * tm)
2505 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
2506 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
2508 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
2509 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
2512 #define _(t,f,n,e) \
2514 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
2515 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
2518 /* SYNs for new connections -> tcp-listen. */
2519 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
2520 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
2521 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2522 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2523 /* SYN-ACK for a SYN */
2524 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2526 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2527 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2528 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2530 /* ACK for for established connection -> tcp-established. */
2531 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2532 /* FIN for for established connection -> tcp-established. */
2533 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2534 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2536 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2537 /* ACK or FIN-ACK to our FIN */
2538 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2539 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
2541 /* FIN in reply to our FIN from the other side */
2542 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2543 /* FIN confirming that the peer (app) has closed */
2544 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2545 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2546 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2548 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2549 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
2554 tcp_input_init (vlib_main_t * vm)
2556 clib_error_t *error = 0;
2557 tcp_main_t *tm = vnet_get_tcp_main ();
2559 if ((error = vlib_call_init_function (vm, tcp_init)))
2562 /* Initialize dispatch table. */
2563 tcp_dispatch_table_init (tm);
2568 VLIB_INIT_FUNCTION (tcp_input_init);
2571 * fd.io coding-style-patch-verification: ON
2574 * eval: (c-set-style "gnu")