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,
997 vlib_buffer_get_current (b),
998 data_len, 1 /* queue event */ );
1000 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1002 /* Update rcv_nxt */
1003 if (PREDICT_TRUE (written == data_len))
1005 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
1007 /* If more data written than expected, account for out-of-order bytes. */
1008 else if (written > data_len)
1010 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end + written - data_len;
1012 /* Send ACK confirming the update */
1013 tc->flags |= TCP_CONN_SNDACK;
1015 else if (written > 0)
1017 /* We've written something but FIFO is probably full now */
1018 tc->rcv_nxt += written;
1020 /* Depending on how fast the app is, all remaining buffers in burst will
1021 * not be enqueued. Inform peer */
1022 tc->flags |= TCP_CONN_SNDACK;
1024 return TCP_ERROR_PARTIALLY_ENQUEUED;
1028 tc->flags |= TCP_CONN_SNDACK;
1029 return TCP_ERROR_FIFO_FULL;
1032 /* Update SACK list if need be */
1033 if (tcp_opts_sack_permitted (&tc->opt))
1035 /* Remove SACK blocks that have been delivered */
1036 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1039 return TCP_ERROR_ENQUEUED;
1042 /** Enqueue out-of-order data */
1044 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1047 stream_session_t *s0;
1050 /* Pure ACK. Do nothing */
1051 if (PREDICT_FALSE (data_len == 0))
1053 return TCP_ERROR_PURE_ACK;
1056 s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
1058 /* Enqueue out-of-order data with absolute offset */
1059 rv = svm_fifo_enqueue_with_offset (s0->server_rx_fifo,
1060 vnet_buffer (b)->tcp.seq_number,
1061 data_len, vlib_buffer_get_current (b));
1063 /* Nothing written */
1066 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1067 return TCP_ERROR_FIFO_FULL;
1070 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1072 /* Update SACK list if in use */
1073 if (tcp_opts_sack_permitted (&tc->opt))
1075 ooo_segment_t *newest;
1078 /* Get the newest segment from the fifo */
1079 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1080 start = ooo_segment_offset (s0->server_rx_fifo, newest);
1081 end = ooo_segment_end_offset (s0->server_rx_fifo, newest);
1083 tcp_update_sack_list (tc, start, end);
1086 return TCP_ERROR_ENQUEUED;
1090 * Check if ACK could be delayed. If ack can be delayed, it should return
1091 * true for a full frame. If we're always acking return 0.
1094 tcp_can_delack (tcp_connection_t * tc)
1096 /* Send ack if ... */
1098 /* just sent a rcv wnd 0 */
1099 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1100 /* constrained to send ack */
1101 || (tc->flags & TCP_CONN_SNDACK) != 0
1102 /* we're almost out of tx wnd */
1103 || tcp_available_snd_space (tc) < 2 * tc->snd_mss)
1110 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1111 u16 n_data_bytes, u32 * next0)
1115 /* Handle out-of-order data */
1116 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1118 /* Old sequence numbers allowed through because they overlapped
1121 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1123 error = TCP_ERROR_SEGMENT_OLD;
1124 *next0 = TCP_NEXT_DROP;
1128 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1130 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1131 * cwnd on remote peer when congested 2) acks leaving should have the
1132 * latest rcv_wnd since the burst may eaten up all of it, so only the
1133 * old ones could be filtered.
1136 /* RFC2581: Send DUPACK for fast retransmit */
1137 tcp_make_ack (tc, b);
1138 *next0 = tcp_next_output (tc->c_is_ip4);
1140 /* Mark as DUPACK. We may filter these in output if
1141 * the burst fills the holes. */
1143 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1145 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1149 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1150 * segments can be enqueued after fifo tail offset changes. */
1151 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1153 if (n_data_bytes == 0)
1155 *next0 = TCP_NEXT_DROP;
1159 /* Check if ACK can be delayed */
1160 if (tcp_can_delack (tc))
1162 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1163 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1167 *next0 = tcp_next_output (tc->c_is_ip4);
1168 tcp_make_ack (tc, b);
1176 tcp_header_t tcp_header;
1177 tcp_connection_t tcp_connection;
1181 format_tcp_rx_trace (u8 * s, va_list * args)
1183 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1184 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1185 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1186 uword indent = format_get_indent (s);
1188 s = format (s, "%U\n%U%U",
1189 format_tcp_header, &t->tcp_header, 128,
1190 format_white_space, indent,
1191 format_tcp_connection_verbose, &t->tcp_connection);
1197 format_tcp_rx_trace_short (u8 * s, va_list * args)
1199 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1200 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1201 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1203 s = format (s, "%d -> %d (%U)",
1204 clib_net_to_host_u16 (t->tcp_header.src_port),
1205 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1206 &t->tcp_connection.state);
1212 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1213 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1217 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1221 th0 = tcp_buffer_hdr (b0);
1223 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1227 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1229 if (PREDICT_TRUE (!val))
1233 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1235 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1239 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1240 vlib_frame_t * from_frame, int is_ip4)
1242 u32 n_left_from, next_index, *from, *to_next;
1243 u32 my_thread_index = vm->thread_index, errors = 0;
1244 tcp_main_t *tm = vnet_get_tcp_main ();
1247 from = vlib_frame_vector_args (from_frame);
1248 n_left_from = from_frame->n_vectors;
1250 next_index = node->cached_next_index;
1252 while (n_left_from > 0)
1256 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1258 while (n_left_from > 0 && n_left_to_next > 0)
1262 tcp_header_t *th0 = 0;
1263 tcp_connection_t *tc0;
1264 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1271 n_left_to_next -= 1;
1273 b0 = vlib_get_buffer (vm, bi0);
1274 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1277 if (PREDICT_FALSE (tc0 == 0))
1279 error0 = TCP_ERROR_INVALID_CONNECTION;
1283 th0 = tcp_buffer_hdr (b0);
1285 is_fin = (th0->flags & TCP_FLAG_FIN) != 0;
1287 /* SYNs, FINs and data consume sequence numbers */
1288 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1289 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1291 /* TODO header prediction fast path */
1293 /* 1-4: check SEQ, RST, SYN */
1294 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1296 error0 = TCP_ERROR_SEGMENT_INVALID;
1297 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1298 vnet_buffer (b0)->tcp.seq_number,
1299 vnet_buffer (b0)->tcp.seq_end);
1303 /* 5: check the ACK field */
1304 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1309 /* 6: check the URG bit TODO */
1311 /* 7: process the segment text */
1313 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1314 error0 = tcp_segment_rcv (tm, tc0, b0,
1315 vnet_buffer (b0)->tcp.data_len, &next0);
1317 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1318 * dangling reference. */
1320 /* 8: check the FIN bit */
1323 /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
1324 * wait for session to call close. To avoid lingering
1325 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1326 tc0->state = TCP_STATE_CLOSE_WAIT;
1327 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1328 stream_session_disconnect_notify (&tc0->connection);
1329 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1333 b0->error = node->errors[error0];
1334 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1336 tcp_rx_trace_t *t0 =
1337 vlib_add_trace (vm, node, b0, sizeof (*t0));
1338 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1341 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1342 n_left_to_next, bi0, next0);
1345 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1348 errors = session_manager_flush_enqueue_events (my_thread_index);
1349 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1351 return from_frame->n_vectors;
1355 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1356 vlib_frame_t * from_frame)
1358 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1362 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1363 vlib_frame_t * from_frame)
1365 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1369 VLIB_REGISTER_NODE (tcp4_established_node) =
1371 .function = tcp4_established,
1372 .name = "tcp4-established",
1373 /* Takes a vector of packets. */
1374 .vector_size = sizeof (u32),
1375 .n_errors = TCP_N_ERROR,
1376 .error_strings = tcp_error_strings,
1377 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1380 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1381 foreach_tcp_state_next
1384 .format_trace = format_tcp_rx_trace_short,
1388 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1391 VLIB_REGISTER_NODE (tcp6_established_node) =
1393 .function = tcp6_established,
1394 .name = "tcp6-established",
1395 /* Takes a vector of packets. */
1396 .vector_size = sizeof (u32),
1397 .n_errors = TCP_N_ERROR,
1398 .error_strings = tcp_error_strings,
1399 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1402 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1403 foreach_tcp_state_next
1406 .format_trace = format_tcp_rx_trace_short,
1411 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1413 vlib_node_registration_t tcp4_syn_sent_node;
1414 vlib_node_registration_t tcp6_syn_sent_node;
1417 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1418 vlib_frame_t * from_frame, int is_ip4)
1420 tcp_main_t *tm = vnet_get_tcp_main ();
1421 u32 n_left_from, next_index, *from, *to_next;
1422 u32 my_thread_index = vm->thread_index, errors = 0;
1423 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
1425 from = vlib_frame_vector_args (from_frame);
1426 n_left_from = from_frame->n_vectors;
1428 next_index = node->cached_next_index;
1430 while (n_left_from > 0)
1434 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1436 while (n_left_from > 0 && n_left_to_next > 0)
1438 u32 bi0, ack0, seq0;
1441 tcp_header_t *tcp0 = 0;
1442 tcp_connection_t *tc0;
1443 tcp_connection_t *new_tc0;
1444 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1451 n_left_to_next -= 1;
1453 b0 = vlib_get_buffer (vm, bi0);
1455 tcp_half_open_connection_get (vnet_buffer (b0)->
1456 tcp.connection_index);
1458 ack0 = vnet_buffer (b0)->tcp.ack_number;
1459 seq0 = vnet_buffer (b0)->tcp.seq_number;
1460 tcp0 = tcp_buffer_hdr (b0);
1463 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1466 /* SYNs, FINs and data consume sequence numbers */
1467 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1468 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
1471 * 1. check the ACK bit
1475 * If the ACK bit is set
1476 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
1477 * the RST bit is set, if so drop the segment and return)
1478 * <SEQ=SEG.ACK><CTL=RST>
1479 * and discard the segment. Return.
1480 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
1484 if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt)
1486 if (!tcp_rst (tcp0))
1487 tcp_send_reset (b0, is_ip4);
1492 /* Make sure ACK is valid */
1493 if (tc0->snd_una > ack0)
1498 * 2. check the RST bit
1503 /* If ACK is acceptable, signal client that peer is not
1504 * willing to accept connection and drop connection*/
1507 stream_session_connect_notify (&tc0->connection, sst,
1509 tcp_connection_cleanup (tc0);
1515 * 3. check the security and precedence (skipped)
1519 * 4. check the SYN bit
1522 /* No SYN flag. Drop. */
1523 if (!tcp_syn (tcp0))
1526 /* Stop connection establishment and retransmit timers */
1527 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
1528 tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT_SYN);
1530 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
1531 * current thread pool. */
1532 pool_get (tm->connections[my_thread_index], new_tc0);
1533 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
1535 new_tc0->c_thread_index = my_thread_index;
1537 /* Cleanup half-open connection XXX lock */
1538 pool_put (tm->half_open_connections, tc0);
1540 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
1541 new_tc0->irs = seq0;
1544 tcp_options_parse (tcp0, &new_tc0->opt);
1546 if (tcp_opts_tstamp (&new_tc0->opt))
1548 new_tc0->tsval_recent = new_tc0->opt.tsval;
1549 new_tc0->tsval_recent_age = tcp_time_now ();
1552 if (tcp_opts_wscale (&new_tc0->opt))
1553 new_tc0->snd_wscale = new_tc0->opt.wscale;
1556 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
1557 new_tc0->snd_wl1 = seq0;
1558 new_tc0->snd_wl2 = ack0;
1560 tcp_connection_init_vars (new_tc0);
1562 /* SYN-ACK: See if we can switch to ESTABLISHED state */
1565 /* Our SYN is ACKed: we have iss < ack = snd_una */
1567 /* TODO Dequeue acknowledged segments if we support Fast Open */
1568 new_tc0->snd_una = ack0;
1569 new_tc0->state = TCP_STATE_ESTABLISHED;
1571 /* Make sure las is initialized for the wnd computation */
1572 new_tc0->rcv_las = new_tc0->rcv_nxt;
1574 /* Notify app that we have connection */
1575 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1577 stream_session_init_fifos_pointers (&new_tc0->connection,
1580 /* Make sure after data segment processing ACK is sent */
1581 new_tc0->flags |= TCP_CONN_SNDACK;
1583 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
1586 new_tc0->state = TCP_STATE_SYN_RCVD;
1588 /* Notify app that we have connection */
1589 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1590 stream_session_init_fifos_pointers (&new_tc0->connection,
1593 tcp_make_synack (new_tc0, b0);
1594 next0 = tcp_next_output (is_ip4);
1599 /* Read data, if any */
1600 if (vnet_buffer (b0)->tcp.data_len)
1602 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1603 error0 = tcp_segment_rcv (tm, new_tc0, b0,
1604 vnet_buffer (b0)->tcp.data_len,
1606 if (error0 == TCP_ERROR_PURE_ACK)
1607 error0 = TCP_ERROR_SYN_ACKS_RCVD;
1611 tcp_make_ack (new_tc0, b0);
1612 next0 = tcp_next_output (new_tc0->c_is_ip4);
1617 b0->error = error0 ? node->errors[error0] : 0;
1618 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1620 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1621 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
1622 clib_memcpy (&t0->tcp_connection, tc0,
1623 sizeof (t0->tcp_connection));
1626 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1627 n_left_to_next, bi0, next0);
1630 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1633 errors = session_manager_flush_enqueue_events (my_thread_index);
1637 vlib_node_increment_counter (vm, tcp4_established_node.index,
1638 TCP_ERROR_EVENT_FIFO_FULL, errors);
1640 vlib_node_increment_counter (vm, tcp6_established_node.index,
1641 TCP_ERROR_EVENT_FIFO_FULL, errors);
1644 return from_frame->n_vectors;
1648 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
1649 vlib_frame_t * from_frame)
1651 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1655 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
1656 vlib_frame_t * from_frame)
1658 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1662 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
1664 .function = tcp4_syn_sent,
1665 .name = "tcp4-syn-sent",
1666 /* Takes a vector of packets. */
1667 .vector_size = sizeof (u32),
1668 .n_errors = TCP_N_ERROR,
1669 .error_strings = tcp_error_strings,
1670 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1673 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1674 foreach_tcp_state_next
1677 .format_trace = format_tcp_rx_trace_short,
1681 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
1684 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
1686 .function = tcp6_syn_sent_rcv,
1687 .name = "tcp6-syn-sent",
1688 /* Takes a vector of packets. */
1689 .vector_size = sizeof (u32),
1690 .n_errors = TCP_N_ERROR,
1691 .error_strings = tcp_error_strings,
1692 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1695 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1696 foreach_tcp_state_next
1699 .format_trace = format_tcp_rx_trace_short,
1703 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
1705 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
1706 * as per RFC793 p. 64
1709 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1710 vlib_frame_t * from_frame, int is_ip4)
1712 tcp_main_t *tm = vnet_get_tcp_main ();
1713 u32 n_left_from, next_index, *from, *to_next;
1714 u32 my_thread_index = vm->thread_index, errors = 0;
1716 from = vlib_frame_vector_args (from_frame);
1717 n_left_from = from_frame->n_vectors;
1719 next_index = node->cached_next_index;
1721 while (n_left_from > 0)
1725 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1727 while (n_left_from > 0 && n_left_to_next > 0)
1731 tcp_header_t *tcp0 = 0;
1732 tcp_connection_t *tc0;
1733 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1740 n_left_to_next -= 1;
1742 b0 = vlib_get_buffer (vm, bi0);
1743 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1745 if (PREDICT_FALSE (tc0 == 0))
1747 error0 = TCP_ERROR_INVALID_CONNECTION;
1751 tcp0 = tcp_buffer_hdr (b0);
1753 /* SYNs, FINs and data consume sequence numbers */
1754 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1755 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0)
1756 + vnet_buffer (b0)->tcp.data_len;
1759 * Special treatment for CLOSED
1763 case TCP_STATE_CLOSED:
1769 * For all other states (except LISTEN)
1772 /* 1-4: check SEQ, RST, SYN */
1774 (tcp_segment_validate (vm, tc0, b0, tcp0, &next0)))
1776 error0 = TCP_ERROR_SEGMENT_INVALID;
1780 /* 5: check the ACK field */
1783 case TCP_STATE_SYN_RCVD:
1785 * If the segment acknowledgment is not acceptable, form a
1787 * <SEQ=SEG.ACK><CTL=RST>
1790 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
1792 tcp_send_reset (b0, is_ip4);
1796 /* Update rtt and rto */
1797 tc0->bytes_acked = 1;
1798 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
1800 /* Switch state to ESTABLISHED */
1801 tc0->state = TCP_STATE_ESTABLISHED;
1803 /* Initialize session variables */
1804 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
1805 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
1807 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
1808 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
1810 /* Shoulder tap the server */
1811 stream_session_accept_notify (&tc0->connection);
1813 /* Reset SYN-ACK retransmit timer */
1814 tcp_retransmit_timer_reset (tc0);
1816 case TCP_STATE_ESTABLISHED:
1817 /* We can get packets in established state here because they
1818 * were enqueued before state change */
1819 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1823 case TCP_STATE_FIN_WAIT_1:
1824 /* In addition to the processing for the ESTABLISHED state, if
1825 * our FIN is now acknowledged then enter FIN-WAIT-2 and
1826 * continue processing in that state. */
1827 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1830 /* If FIN is ACKed */
1831 if (tc0->snd_una == tc0->snd_una_max)
1833 tc0->state = TCP_STATE_FIN_WAIT_2;
1834 /* Stop all timers, 2MSL will be set lower */
1835 tcp_connection_timers_reset (tc0);
1838 case TCP_STATE_FIN_WAIT_2:
1839 /* In addition to the processing for the ESTABLISHED state, if
1840 * the retransmission queue is empty, the user's CLOSE can be
1841 * acknowledged ("ok") but do not delete the TCB. */
1842 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1844 /* check if rtx queue is empty and ack CLOSE TODO */
1846 case TCP_STATE_CLOSE_WAIT:
1847 /* Do the same processing as for the ESTABLISHED state. */
1848 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1851 case TCP_STATE_CLOSING:
1852 /* In addition to the processing for the ESTABLISHED state, if
1853 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
1854 * otherwise ignore the segment. */
1855 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1858 /* XXX test that send queue empty */
1859 tc0->state = TCP_STATE_TIME_WAIT;
1863 case TCP_STATE_LAST_ACK:
1864 /* The only thing that can arrive in this state is an
1865 * acknowledgment of our FIN. If our FIN is now acknowledged,
1866 * delete the TCB, enter the CLOSED state, and return. */
1868 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
1871 tc0->state = TCP_STATE_CLOSED;
1873 /* Don't delete the connection/session yet. Instead, wait a
1874 * reasonable amount of time until the pipes are cleared. In
1875 * particular, this makes sure that we won't have dead sessions
1876 * when processing events on the tx path */
1877 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
1879 /* Stop retransmit */
1880 tcp_retransmit_timer_reset (tc0);
1885 case TCP_STATE_TIME_WAIT:
1886 /* The only thing that can arrive in this state is a
1887 * retransmission of the remote FIN. Acknowledge it, and restart
1888 * the 2 MSL timeout. */
1897 /* 6: check the URG bit TODO */
1899 /* 7: process the segment text */
1902 case TCP_STATE_ESTABLISHED:
1903 case TCP_STATE_FIN_WAIT_1:
1904 case TCP_STATE_FIN_WAIT_2:
1905 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1906 error0 = tcp_segment_rcv (tm, tc0, b0,
1907 vnet_buffer (b0)->tcp.data_len,
1910 case TCP_STATE_CLOSE_WAIT:
1911 case TCP_STATE_CLOSING:
1912 case TCP_STATE_LAST_ACK:
1913 case TCP_STATE_TIME_WAIT:
1914 /* This should not occur, since a FIN has been received from the
1915 * remote side. Ignore the segment text. */
1919 /* 8: check the FIN bit */
1920 if (!tcp_fin (tcp0))
1925 case TCP_STATE_ESTABLISHED:
1926 case TCP_STATE_SYN_RCVD:
1927 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
1928 tcp_connection_timers_reset (tc0);
1929 tcp_make_fin (tc0, b0);
1930 next0 = tcp_next_output (tc0->c_is_ip4);
1931 stream_session_disconnect_notify (&tc0->connection);
1932 tc0->state = TCP_STATE_CLOSE_WAIT;
1934 case TCP_STATE_CLOSE_WAIT:
1935 case TCP_STATE_CLOSING:
1936 case TCP_STATE_LAST_ACK:
1939 case TCP_STATE_FIN_WAIT_1:
1940 tc0->state = TCP_STATE_TIME_WAIT;
1941 tcp_connection_timers_reset (tc0);
1942 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
1944 case TCP_STATE_FIN_WAIT_2:
1945 /* Got FIN, send ACK! */
1946 tc0->state = TCP_STATE_TIME_WAIT;
1947 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1948 tcp_make_ack (tc0, b0);
1949 next0 = tcp_next_output (is_ip4);
1951 case TCP_STATE_TIME_WAIT:
1952 /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
1955 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
1958 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1961 b0->error = error0 ? node->errors[error0] : 0;
1963 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1965 tcp_rx_trace_t *t0 =
1966 vlib_add_trace (vm, node, b0, sizeof (*t0));
1967 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
1970 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1971 n_left_to_next, bi0, next0);
1974 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1977 errors = session_manager_flush_enqueue_events (my_thread_index);
1981 vlib_node_increment_counter (vm, tcp4_established_node.index,
1982 TCP_ERROR_EVENT_FIFO_FULL, errors);
1984 vlib_node_increment_counter (vm, tcp6_established_node.index,
1985 TCP_ERROR_EVENT_FIFO_FULL, errors);
1988 return from_frame->n_vectors;
1992 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
1993 vlib_frame_t * from_frame)
1995 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1999 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2000 vlib_frame_t * from_frame)
2002 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2006 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2008 .function = tcp4_rcv_process,
2009 .name = "tcp4-rcv-process",
2010 /* Takes a vector of packets. */
2011 .vector_size = sizeof (u32),
2012 .n_errors = TCP_N_ERROR,
2013 .error_strings = tcp_error_strings,
2014 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2017 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2018 foreach_tcp_state_next
2021 .format_trace = format_tcp_rx_trace_short,
2025 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2028 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2030 .function = tcp6_rcv_process,
2031 .name = "tcp6-rcv-process",
2032 /* Takes a vector of packets. */
2033 .vector_size = sizeof (u32),
2034 .n_errors = TCP_N_ERROR,
2035 .error_strings = tcp_error_strings,
2036 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2039 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2040 foreach_tcp_state_next
2043 .format_trace = format_tcp_rx_trace_short,
2047 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2049 vlib_node_registration_t tcp4_listen_node;
2050 vlib_node_registration_t tcp6_listen_node;
2053 * LISTEN state processing as per RFC 793 p. 65
2056 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2057 vlib_frame_t * from_frame, int is_ip4)
2059 u32 n_left_from, next_index, *from, *to_next;
2060 u32 my_thread_index = vm->thread_index;
2061 tcp_main_t *tm = vnet_get_tcp_main ();
2062 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
2064 from = vlib_frame_vector_args (from_frame);
2065 n_left_from = from_frame->n_vectors;
2067 next_index = node->cached_next_index;
2069 while (n_left_from > 0)
2073 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2075 while (n_left_from > 0 && n_left_to_next > 0)
2080 tcp_header_t *th0 = 0;
2081 tcp_connection_t *lc0;
2084 tcp_connection_t *child0;
2085 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2092 n_left_to_next -= 1;
2094 b0 = vlib_get_buffer (vm, bi0);
2095 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2099 ip40 = vlib_buffer_get_current (b0);
2100 th0 = ip4_next_header (ip40);
2104 ip60 = vlib_buffer_get_current (b0);
2105 th0 = ip6_next_header (ip60);
2108 /* Create child session. For syn-flood protection use filter */
2110 /* 1. first check for an RST */
2114 /* 2. second check for an ACK */
2117 tcp_send_reset (b0, is_ip4);
2121 /* 3. check for a SYN (did that already) */
2123 /* Create child session and send SYN-ACK */
2124 pool_get (tm->connections[my_thread_index], child0);
2125 memset (child0, 0, sizeof (*child0));
2127 child0->c_c_index = child0 - tm->connections[my_thread_index];
2128 child0->c_lcl_port = lc0->c_lcl_port;
2129 child0->c_rmt_port = th0->src_port;
2130 child0->c_is_ip4 = is_ip4;
2131 child0->c_thread_index = my_thread_index;
2135 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2136 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2140 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2141 sizeof (ip6_address_t));
2142 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2143 sizeof (ip6_address_t));
2146 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2149 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2153 tcp_options_parse (th0, &child0->opt);
2155 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2156 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2157 child0->rcv_las = child0->rcv_nxt;
2158 child0->state = TCP_STATE_SYN_RCVD;
2160 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2161 * segments are used to initialize PAWS. */
2162 if (tcp_opts_tstamp (&child0->opt))
2164 child0->tsval_recent = child0->opt.tsval;
2165 child0->tsval_recent_age = tcp_time_now ();
2168 if (tcp_opts_wscale (&child0->opt))
2169 child0->snd_wscale = child0->opt.wscale;
2172 child0->snd_wnd = clib_net_to_host_u16 (th0->window);
2173 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2174 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2176 tcp_connection_init_vars (child0);
2178 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0);
2180 /* Reuse buffer to make syn-ack and send */
2181 tcp_make_synack (child0, b0);
2182 next0 = tcp_next_output (is_ip4);
2184 /* Init fifo pointers after we have iss */
2185 stream_session_init_fifos_pointers (&child0->connection,
2189 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2191 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2192 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2193 clib_memcpy (&t0->tcp_connection, lc0,
2194 sizeof (t0->tcp_connection));
2197 b0->error = node->errors[error0];
2199 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2200 n_left_to_next, bi0, next0);
2203 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2205 return from_frame->n_vectors;
2209 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2210 vlib_frame_t * from_frame)
2212 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2216 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2217 vlib_frame_t * from_frame)
2219 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2223 VLIB_REGISTER_NODE (tcp4_listen_node) =
2225 .function = tcp4_listen,
2226 .name = "tcp4-listen",
2227 /* Takes a vector of packets. */
2228 .vector_size = sizeof (u32),
2229 .n_errors = TCP_N_ERROR,
2230 .error_strings = tcp_error_strings,
2231 .n_next_nodes = TCP_LISTEN_N_NEXT,
2234 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2235 foreach_tcp_state_next
2238 .format_trace = format_tcp_rx_trace_short,
2242 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2245 VLIB_REGISTER_NODE (tcp6_listen_node) =
2247 .function = tcp6_listen,
2248 .name = "tcp6-listen",
2249 /* Takes a vector of packets. */
2250 .vector_size = sizeof (u32),
2251 .n_errors = TCP_N_ERROR,
2252 .error_strings = tcp_error_strings,
2253 .n_next_nodes = TCP_LISTEN_N_NEXT,
2256 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2257 foreach_tcp_state_next
2260 .format_trace = format_tcp_rx_trace_short,
2264 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2266 vlib_node_registration_t tcp4_input_node;
2267 vlib_node_registration_t tcp6_input_node;
2269 typedef enum _tcp_input_next
2271 TCP_INPUT_NEXT_DROP,
2272 TCP_INPUT_NEXT_LISTEN,
2273 TCP_INPUT_NEXT_RCV_PROCESS,
2274 TCP_INPUT_NEXT_SYN_SENT,
2275 TCP_INPUT_NEXT_ESTABLISHED,
2276 TCP_INPUT_NEXT_RESET,
2280 #define foreach_tcp4_input_next \
2281 _ (DROP, "error-drop") \
2282 _ (LISTEN, "tcp4-listen") \
2283 _ (RCV_PROCESS, "tcp4-rcv-process") \
2284 _ (SYN_SENT, "tcp4-syn-sent") \
2285 _ (ESTABLISHED, "tcp4-established") \
2286 _ (RESET, "tcp4-reset")
2288 #define foreach_tcp6_input_next \
2289 _ (DROP, "error-drop") \
2290 _ (LISTEN, "tcp6-listen") \
2291 _ (RCV_PROCESS, "tcp6-rcv-process") \
2292 _ (SYN_SENT, "tcp6-syn-sent") \
2293 _ (ESTABLISHED, "tcp6-established") \
2294 _ (RESET, "tcp6-reset")
2296 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2299 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2300 vlib_frame_t * from_frame, int is_ip4)
2302 u32 n_left_from, next_index, *from, *to_next;
2303 u32 my_thread_index = vm->thread_index;
2304 tcp_main_t *tm = vnet_get_tcp_main ();
2306 from = vlib_frame_vector_args (from_frame);
2307 n_left_from = from_frame->n_vectors;
2309 next_index = node->cached_next_index;
2311 while (n_left_from > 0)
2315 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2317 while (n_left_from > 0 && n_left_to_next > 0)
2319 int n_advance_bytes0, n_data_bytes0;
2322 tcp_header_t *tcp0 = 0;
2323 tcp_connection_t *tc0;
2326 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2334 n_left_to_next -= 1;
2336 b0 = vlib_get_buffer (vm, bi0);
2337 vnet_buffer (b0)->tcp.flags = 0;
2339 /* Checksum computed by ipx_local no need to compute again */
2343 ip40 = vlib_buffer_get_current (b0);
2344 tcp0 = ip4_next_header (ip40);
2345 n_advance_bytes0 = (ip4_header_bytes (ip40)
2346 + tcp_header_bytes (tcp0));
2347 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2350 /* lookup session */
2352 (tcp_connection_t *)
2353 stream_session_lookup_transport4 (&ip40->dst_address,
2357 SESSION_TYPE_IP4_TCP,
2362 ip60 = vlib_buffer_get_current (b0);
2363 tcp0 = ip6_next_header (ip60);
2364 n_advance_bytes0 = tcp_header_bytes (tcp0);
2365 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2367 n_advance_bytes0 += sizeof (ip60[0]);
2370 (tcp_connection_t *)
2371 stream_session_lookup_transport6 (&ip60->src_address,
2375 SESSION_TYPE_IP6_TCP,
2380 if (PREDICT_FALSE (n_advance_bytes0 < 0))
2382 error0 = TCP_ERROR_LENGTH;
2386 /* Session exists */
2387 if (PREDICT_TRUE (0 != tc0))
2389 /* Save connection index */
2390 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2391 vnet_buffer (b0)->tcp.seq_number =
2392 clib_net_to_host_u32 (tcp0->seq_number);
2393 vnet_buffer (b0)->tcp.ack_number =
2394 clib_net_to_host_u32 (tcp0->ack_number);
2396 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
2397 - (u8 *) vlib_buffer_get_current (b0);
2398 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
2399 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
2401 flags0 = tcp0->flags & filter_flags;
2402 next0 = tm->dispatch_table[tc0->state][flags0].next;
2403 error0 = tm->dispatch_table[tc0->state][flags0].error;
2405 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH))
2407 tcp_state_t state0 = tc0->state;
2408 /* Overload tcp flags to store state */
2409 vnet_buffer (b0)->tcp.flags = tc0->state;
2410 clib_warning ("disp error state %U flags %U",
2411 format_tcp_state, &state0,
2412 format_tcp_flags, (int) flags0);
2418 next0 = TCP_INPUT_NEXT_RESET;
2419 error0 = TCP_ERROR_NO_LISTENER;
2423 b0->error = error0 ? node->errors[error0] : 0;
2425 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2427 tcp_rx_trace_t *t0 =
2428 vlib_add_trace (vm, node, b0, sizeof (*t0));
2429 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2432 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2433 n_left_to_next, bi0, next0);
2436 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2439 return from_frame->n_vectors;
2443 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2444 vlib_frame_t * from_frame)
2446 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2450 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2451 vlib_frame_t * from_frame)
2453 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2457 VLIB_REGISTER_NODE (tcp4_input_node) =
2459 .function = tcp4_input,
2460 .name = "tcp4-input",
2461 /* Takes a vector of packets. */
2462 .vector_size = sizeof (u32),
2463 .n_errors = TCP_N_ERROR,
2464 .error_strings = tcp_error_strings,
2465 .n_next_nodes = TCP_INPUT_N_NEXT,
2468 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2469 foreach_tcp4_input_next
2472 .format_buffer = format_tcp_header,
2473 .format_trace = format_tcp_rx_trace,
2477 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
2480 VLIB_REGISTER_NODE (tcp6_input_node) =
2482 .function = tcp6_input,
2483 .name = "tcp6-input",
2484 /* Takes a vector of packets. */
2485 .vector_size = sizeof (u32),
2486 .n_errors = TCP_N_ERROR,
2487 .error_strings = tcp_error_strings,
2488 .n_next_nodes = TCP_INPUT_N_NEXT,
2491 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2492 foreach_tcp6_input_next
2495 .format_buffer = format_tcp_header,
2496 .format_trace = format_tcp_rx_trace,
2500 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
2503 tcp_dispatch_table_init (tcp_main_t * tm)
2506 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
2507 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
2509 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
2510 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
2513 #define _(t,f,n,e) \
2515 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
2516 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
2519 /* SYNs for new connections -> tcp-listen. */
2520 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
2521 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
2522 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2523 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2524 /* SYN-ACK for a SYN */
2525 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2527 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2528 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2529 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2531 /* ACK for for established connection -> tcp-established. */
2532 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2533 /* FIN for for established connection -> tcp-established. */
2534 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2535 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2537 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2538 /* ACK or FIN-ACK to our FIN */
2539 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2540 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
2542 /* FIN in reply to our FIN from the other side */
2543 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2544 /* FIN confirming that the peer (app) has closed */
2545 _(FIN_WAIT_2, TCP_FLAG_FIN, 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")