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)
393 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
394 * RTT because they're ambiguous. */
395 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq) && !tc->rto_boff)
397 mrtt = tcp_time_now () - tc->rtt_ts;
399 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
400 * snd_una, i.e., the left side of the send window:
401 * seq_lt (tc->snd_una, ack). Note: last condition could be dropped, we don't
402 * try to update rtt for dupacks */
403 else if (tcp_opts_tstamp (&tc->opt) && tc->opt.tsecr && tc->bytes_acked)
405 mrtt = tcp_time_now () - tc->opt.tsecr;
408 /* Allow measuring of a new RTT */
411 /* If ACK moves left side of the wnd make sure boff is 0, even if mrtt is
416 /* Ignore dubious measurements */
417 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
420 tcp_estimate_rtt (tc, mrtt);
421 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
427 * Dequeue bytes that have been acked and while at it update RTT estimates.
430 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
432 /* Dequeue the newly ACKed bytes */
433 stream_session_dequeue_drop (&tc->connection, tc->bytes_acked);
435 /* Update rtt and rto */
436 tcp_update_rtt (tc, ack);
440 * Check if dupack as per RFC5681 Sec. 2
442 * This works only if called before updating snd_wnd.
445 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 new_snd_wnd)
447 return ((vnet_buffer (b)->tcp.ack_number == tc->snd_una)
448 && seq_gt (tc->snd_una_max, tc->snd_una)
449 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
450 && (new_snd_wnd == tc->snd_wnd));
454 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
456 sack_scoreboard_hole_t *next, *prev;
458 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
460 next = pool_elt_at_index (sb->holes, hole->next);
461 next->prev = hole->prev;
464 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
466 prev = pool_elt_at_index (sb->holes, hole->prev);
467 prev->next = hole->next;
471 sb->head = hole->next;
474 pool_put (sb->holes, hole);
477 sack_scoreboard_hole_t *
478 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
481 sack_scoreboard_hole_t *hole, *next, *prev;
484 pool_get (sb->holes, hole);
485 memset (hole, 0, sizeof (*hole));
489 hole_index = hole - sb->holes;
491 prev = scoreboard_get_hole (sb, prev_index);
494 hole->prev = prev - sb->holes;
495 hole->next = prev->next;
497 if ((next = scoreboard_next_hole (sb, hole)))
498 next->prev = hole_index;
500 prev->next = hole_index;
504 sb->head = hole_index;
505 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
506 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
513 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
515 sack_scoreboard_t *sb = &tc->sack_sb;
516 sack_block_t *blk, tmp;
517 sack_scoreboard_hole_t *hole, *next_hole, *last_hole, *new_hole;
518 u32 blk_index = 0, old_sacked_bytes, hole_index;
521 sb->last_sacked_bytes = 0;
523 old_sacked_bytes = sb->sacked_bytes;
525 if (!tcp_opts_sack (&tc->opt) && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
528 /* Remove invalid blocks */
530 while (blk < vec_end (tc->opt.sacks))
532 if (seq_lt (blk->start, blk->end)
533 && seq_gt (blk->start, tc->snd_una)
534 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_nxt))
539 vec_del1 (tc->opt.sacks, blk - tc->opt.sacks);
542 /* Add block for cumulative ack */
543 if (seq_gt (ack, tc->snd_una))
545 tmp.start = tc->snd_una;
547 vec_add1 (tc->opt.sacks, tmp);
550 if (vec_len (tc->opt.sacks) == 0)
553 /* Make sure blocks are ordered */
554 for (i = 0; i < vec_len (tc->opt.sacks); i++)
555 for (j = i + 1; j < vec_len (tc->opt.sacks); j++)
556 if (seq_lt (tc->opt.sacks[j].start, tc->opt.sacks[i].start))
558 tmp = tc->opt.sacks[i];
559 tc->opt.sacks[i] = tc->opt.sacks[j];
560 tc->opt.sacks[j] = tmp;
563 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
565 /* If no holes, insert the first that covers all outstanding bytes */
566 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
567 tc->snd_una, tc->snd_una_max);
568 sb->tail = scoreboard_hole_index (sb, last_hole);
572 /* If we have holes but snd_una_max is beyond the last hole, update
574 tmp = tc->opt.sacks[vec_len (tc->opt.sacks) - 1];
575 last_hole = scoreboard_last_hole (sb);
576 if (seq_gt (tc->snd_una_max, sb->max_byte_sacked)
577 && seq_gt (tc->snd_una_max, last_hole->end))
578 last_hole->end = tc->snd_una_max;
581 /* Walk the holes with the SACK blocks */
582 hole = pool_elt_at_index (sb->holes, sb->head);
583 while (hole && blk_index < vec_len (tc->opt.sacks))
585 blk = &tc->opt.sacks[blk_index];
587 if (seq_leq (blk->start, hole->start))
589 /* Block covers hole. Remove hole */
590 if (seq_geq (blk->end, hole->end))
592 next_hole = scoreboard_next_hole (sb, hole);
594 /* Byte accounting */
595 if (seq_leq (hole->end, ack))
597 /* Bytes lost because snd_wnd left edge advances */
598 if (next_hole && seq_leq (next_hole->start, ack))
599 sb->sacked_bytes -= next_hole->start - hole->end;
601 sb->sacked_bytes -= ack - hole->end;
605 sb->sacked_bytes += scoreboard_hole_bytes (hole);
608 /* snd_una needs to be advanced */
609 if (seq_geq (ack, hole->end))
611 if (next_hole && seq_lt (ack, next_hole->start))
612 sb->snd_una_adv = next_hole->start - ack;
614 sb->snd_una_adv = sb->max_byte_sacked - ack;
616 /* all these can be delivered */
617 sb->sacked_bytes -= sb->snd_una_adv;
620 /* About to remove last hole */
621 if (hole == last_hole)
623 sb->tail = hole->prev;
624 last_hole = scoreboard_last_hole (sb);
625 /* keep track of max byte sacked in case the last hole
627 if (seq_gt (hole->end, sb->max_byte_sacked))
628 sb->max_byte_sacked = hole->end;
630 scoreboard_remove_hole (sb, hole);
633 /* Partial 'head' overlap */
636 if (seq_gt (blk->end, hole->start))
638 sb->sacked_bytes += blk->end - hole->start;
639 hole->start = blk->end;
646 /* Hole must be split */
647 if (seq_lt (blk->end, hole->end))
649 sb->sacked_bytes += blk->end - blk->start;
650 hole_index = scoreboard_hole_index (sb, hole);
651 new_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
654 /* Pool might've moved */
655 hole = scoreboard_get_hole (sb, hole_index);
656 hole->end = blk->start;
658 /* New or split of tail */
659 if ((last_hole->end == new_hole->end)
660 || seq_lt (last_hole->end, new_hole->start))
662 last_hole = new_hole;
663 sb->tail = scoreboard_hole_index (sb, new_hole);
667 hole = scoreboard_next_hole (sb, hole);
671 sb->sacked_bytes += hole->end - blk->start;
672 hole->end = blk->start;
673 hole = scoreboard_next_hole (sb, hole);
678 sb->last_sacked_bytes = sb->sacked_bytes + sb->snd_una_adv
684 * If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
685 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
687 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
689 if (seq_lt (tc->snd_wl1, seq)
690 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
692 tc->snd_wnd = snd_wnd;
695 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
697 /* Set probe timer if we just got 0 wnd */
698 if (tc->snd_wnd < tc->snd_mss
699 && !tcp_timer_is_active (tc, TCP_TIMER_PERSIST))
700 tcp_persist_timer_set (tc);
702 tcp_persist_timer_reset (tc);
707 tcp_cc_congestion (tcp_connection_t * tc)
709 tc->snd_congestion = tc->snd_nxt;
710 tc->cc_algo->congestion (tc);
711 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
715 tcp_cc_recover (tcp_connection_t * tc)
717 /* TODO: check if time to recover was small. It might be that RTO popped
721 tc->cc_algo->recovered (tc);
725 tc->snd_nxt = tc->snd_una;
727 tc->cc_algo->rcv_ack (tc);
728 tc->tsecr_last_ack = tc->opt.tsecr;
730 tcp_cong_recovery_off (tc);
732 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
736 tcp_cc_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b)
740 if (tcp_in_fastrecovery (tc))
742 partial_ack = seq_lt (tc->snd_una, tc->snd_congestion);
745 /* Clear retransmitted bytes. */
750 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
752 /* Clear retransmitted bytes. XXX should we clear all? */
755 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
757 /* In case snd_nxt is still in the past and output tries to
758 * shove some new bytes */
759 tc->snd_nxt = tc->snd_una_max;
761 /* XXX need proper RFC6675 support */
762 if (tc->sack_sb.last_sacked_bytes && !tcp_in_recovery (tc))
764 tcp_fast_retransmit (tc);
768 /* Retransmit first unacked segment */
769 tcp_retransmit_first_unacked (tc);
775 tc->cc_algo->rcv_ack (tc);
776 tc->tsecr_last_ack = tc->opt.tsecr;
778 if (tcp_in_recovery (tc))
780 tc->rtx_bytes -= clib_min (tc->bytes_acked, tc->rtx_bytes);
781 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
782 if (seq_geq (tc->snd_una, tc->snd_congestion))
783 tcp_recovery_off (tc);
789 tcp_cc_rcv_dupack (tcp_connection_t * tc, u32 ack)
791 // ASSERT (seq_geq(tc->snd_una, ack));
794 if (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
796 /* RFC6582 NewReno heuristic to avoid multiple fast retransmits */
797 if (tc->opt.tsecr != tc->tsecr_last_ack)
803 tcp_fastrecovery_on (tc);
805 /* Handle congestion and dupack */
806 tcp_cc_congestion (tc);
807 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
809 tcp_fast_retransmit (tc);
811 /* Post retransmit update cwnd to ssthresh and account for the
812 * three segments that have left the network and should've been
813 * buffered at the receiver */
814 tc->cwnd = tc->ssthresh + TCP_DUPACK_THRESHOLD * tc->snd_mss;
816 else if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD)
818 ASSERT (tcp_in_fastrecovery (tc));
820 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
825 tcp_cc_init (tcp_connection_t * tc)
827 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
828 tc->cc_algo->init (tc);
832 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
833 tcp_header_t * th, u32 * next, u32 * error)
837 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
838 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt))
840 /* If we have outstanding data and this is within the window, accept it,
841 * probably retransmit has timed out. Otherwise ACK segment and then
843 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
845 tcp_make_ack (tc, b);
846 *next = tcp_next_output (tc->c_is_ip4);
847 *error = TCP_ERROR_ACK_INVALID;
848 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
849 vnet_buffer (b)->tcp.ack_number);
853 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
854 vnet_buffer (b)->tcp.ack_number);
856 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
857 *error = TCP_ERROR_ACK_FUTURE;
860 /* If old ACK, probably it's an old dupack */
861 if (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
863 *error = TCP_ERROR_ACK_OLD;
864 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
865 vnet_buffer (b)->tcp.ack_number);
866 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
868 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
869 tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number);
875 if (tcp_opts_sack_permitted (&tc->opt))
876 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
878 new_snd_wnd = clib_net_to_host_u16 (th->window) << tc->snd_wscale;
880 if (tcp_ack_is_dupack (tc, b, new_snd_wnd))
882 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
883 tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number);
884 *error = TCP_ERROR_ACK_DUP;
892 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
893 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
895 /* Dequeue ACKed data and update RTT */
896 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
897 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
898 vnet_buffer (b)->tcp.ack_number, new_snd_wnd);
900 /* If some of our sent bytes have been acked, update cc and retransmit
904 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
906 /* Updates congestion control (slow start/congestion avoidance) */
907 tcp_cc_rcv_ack (tc, b);
909 /* If everything has been acked, stop retransmit timer
910 * otherwise update. */
911 if (tc->snd_una == tc->snd_una_max)
912 tcp_retransmit_timer_reset (tc);
914 tcp_retransmit_timer_update (tc);
921 * Build SACK list as per RFC2018.
923 * Makes sure the first block contains the segment that generated the current
924 * ACK and the following ones are the ones most recently reported in SACK
927 * @param tc TCP connection for which the SACK list is updated
928 * @param start Start sequence number of the newest SACK block
929 * @param end End sequence of the newest SACK block
932 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
934 sack_block_t *new_list = 0, *block = 0;
937 /* If the first segment is ooo add it to the list. Last write might've moved
938 * rcv_nxt over the first segment. */
939 if (seq_lt (tc->rcv_nxt, start))
941 vec_add2 (new_list, block, 1);
942 block->start = start;
946 /* Find the blocks still worth keeping. */
947 for (i = 0; i < vec_len (tc->snd_sacks); i++)
949 /* Discard if rcv_nxt advanced beyond current block */
950 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
953 /* Merge or drop if segment overlapped by the new segment */
954 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
955 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
957 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
958 new_list[0].start = tc->snd_sacks[i].start;
959 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
960 new_list[0].end = tc->snd_sacks[i].end;
964 /* Save to new SACK list if we have space. */
965 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
967 vec_add1 (new_list, tc->snd_sacks[i]);
971 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
973 /* Replace old vector with new one */
974 vec_free (tc->snd_sacks);
975 tc->snd_sacks = new_list;
978 /** Enqueue data for delivery to application */
980 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
985 /* Pure ACK. Update rcv_nxt and be done. */
986 if (PREDICT_FALSE (data_len == 0))
988 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
989 return TCP_ERROR_PURE_ACK;
992 written = stream_session_enqueue_data (&tc->connection,
993 vlib_buffer_get_current (b),
994 data_len, 1 /* queue event */ );
996 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
999 if (PREDICT_TRUE (written == data_len))
1001 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
1003 /* If more data written than expected, account for out-of-order bytes. */
1004 else if (written > data_len)
1006 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end + written - data_len;
1008 /* Send ACK confirming the update */
1009 tc->flags |= TCP_CONN_SNDACK;
1011 else if (written > 0)
1013 /* We've written something but FIFO is probably full now */
1014 tc->rcv_nxt += written;
1016 /* Depending on how fast the app is, all remaining buffers in burst will
1017 * not be enqueued. Inform peer */
1018 tc->flags |= TCP_CONN_SNDACK;
1020 return TCP_ERROR_PARTIALLY_ENQUEUED;
1024 tc->flags |= TCP_CONN_SNDACK;
1025 return TCP_ERROR_FIFO_FULL;
1028 /* Update SACK list if need be */
1029 if (tcp_opts_sack_permitted (&tc->opt))
1031 /* Remove SACK blocks that have been delivered */
1032 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1035 return TCP_ERROR_ENQUEUED;
1038 /** Enqueue out-of-order data */
1040 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1043 stream_session_t *s0;
1046 /* Pure ACK. Do nothing */
1047 if (PREDICT_FALSE (data_len == 0))
1049 return TCP_ERROR_PURE_ACK;
1052 s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
1054 /* Enqueue out-of-order data with absolute offset */
1055 rv = svm_fifo_enqueue_with_offset (s0->server_rx_fifo,
1056 vnet_buffer (b)->tcp.seq_number,
1057 data_len, vlib_buffer_get_current (b));
1059 /* Nothing written */
1062 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1063 return TCP_ERROR_FIFO_FULL;
1066 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1068 /* Update SACK list if in use */
1069 if (tcp_opts_sack_permitted (&tc->opt))
1071 ooo_segment_t *newest;
1074 /* Get the newest segment from the fifo */
1075 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1076 start = ooo_segment_offset (s0->server_rx_fifo, newest);
1077 end = ooo_segment_end_offset (s0->server_rx_fifo, newest);
1079 tcp_update_sack_list (tc, start, end);
1082 return TCP_ERROR_ENQUEUED;
1086 * Check if ACK could be delayed. If ack can be delayed, it should return
1087 * true for a full frame. If we're always acking return 0.
1090 tcp_can_delack (tcp_connection_t * tc)
1092 /* Send ack if ... */
1094 /* just sent a rcv wnd 0 */
1095 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1096 /* constrained to send ack */
1097 || (tc->flags & TCP_CONN_SNDACK) != 0
1098 /* we're almost out of tx wnd */
1099 || tcp_available_snd_space (tc) < 2 * tc->snd_mss)
1106 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1107 u16 n_data_bytes, u32 * next0)
1111 /* Handle out-of-order data */
1112 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1114 /* Old sequence numbers allowed through because they overlapped
1117 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1119 error = TCP_ERROR_SEGMENT_OLD;
1120 *next0 = TCP_NEXT_DROP;
1124 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1126 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1127 * cwnd on remote peer when congested 2) acks leaving should have the
1128 * latest rcv_wnd since the burst may eaten up all of it, so only the
1129 * old ones could be filtered.
1132 /* RFC2581: Send DUPACK for fast retransmit */
1133 tcp_make_ack (tc, b);
1134 *next0 = tcp_next_output (tc->c_is_ip4);
1136 /* Mark as DUPACK. We may filter these in output if
1137 * the burst fills the holes. */
1139 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1141 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1145 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1146 * segments can be enqueued after fifo tail offset changes. */
1147 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1149 if (n_data_bytes == 0)
1151 *next0 = TCP_NEXT_DROP;
1155 /* Check if ACK can be delayed */
1156 if (tcp_can_delack (tc))
1158 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1159 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1163 *next0 = tcp_next_output (tc->c_is_ip4);
1164 tcp_make_ack (tc, b);
1172 tcp_header_t tcp_header;
1173 tcp_connection_t tcp_connection;
1177 format_tcp_rx_trace (u8 * s, va_list * args)
1179 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1180 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1181 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1182 uword indent = format_get_indent (s);
1184 s = format (s, "%U\n%U%U",
1185 format_tcp_header, &t->tcp_header, 128,
1186 format_white_space, indent,
1187 format_tcp_connection_verbose, &t->tcp_connection);
1193 format_tcp_rx_trace_short (u8 * s, va_list * args)
1195 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1196 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1197 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1199 s = format (s, "%d -> %d (%U)",
1200 clib_net_to_host_u16 (t->tcp_header.src_port),
1201 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1202 &t->tcp_connection.state);
1208 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1209 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1213 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1217 th0 = tcp_buffer_hdr (b0);
1219 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1223 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1225 if (PREDICT_TRUE (!val))
1229 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1231 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1235 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1236 vlib_frame_t * from_frame, int is_ip4)
1238 u32 n_left_from, next_index, *from, *to_next;
1239 u32 my_thread_index = vm->thread_index, errors = 0;
1240 tcp_main_t *tm = vnet_get_tcp_main ();
1243 from = vlib_frame_vector_args (from_frame);
1244 n_left_from = from_frame->n_vectors;
1246 next_index = node->cached_next_index;
1248 while (n_left_from > 0)
1252 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1254 while (n_left_from > 0 && n_left_to_next > 0)
1258 tcp_header_t *th0 = 0;
1259 tcp_connection_t *tc0;
1260 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1267 n_left_to_next -= 1;
1269 b0 = vlib_get_buffer (vm, bi0);
1270 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1273 if (PREDICT_FALSE (tc0 == 0))
1275 error0 = TCP_ERROR_INVALID_CONNECTION;
1279 th0 = tcp_buffer_hdr (b0);
1281 is_fin = (th0->flags & TCP_FLAG_FIN) != 0;
1283 /* SYNs, FINs and data consume sequence numbers */
1284 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1285 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1287 /* TODO header prediction fast path */
1289 /* 1-4: check SEQ, RST, SYN */
1290 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1292 error0 = TCP_ERROR_SEGMENT_INVALID;
1293 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1294 vnet_buffer (b0)->tcp.seq_number,
1295 vnet_buffer (b0)->tcp.seq_end);
1299 /* 5: check the ACK field */
1300 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1305 /* 6: check the URG bit TODO */
1307 /* 7: process the segment text */
1309 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1310 error0 = tcp_segment_rcv (tm, tc0, b0,
1311 vnet_buffer (b0)->tcp.data_len, &next0);
1313 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1314 * dangling reference. */
1316 /* 8: check the FIN bit */
1319 /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
1320 * wait for session to call close. To avoid lingering
1321 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1322 tc0->state = TCP_STATE_CLOSE_WAIT;
1323 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1324 stream_session_disconnect_notify (&tc0->connection);
1325 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1329 b0->error = node->errors[error0];
1330 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1332 tcp_rx_trace_t *t0 =
1333 vlib_add_trace (vm, node, b0, sizeof (*t0));
1334 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1337 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1338 n_left_to_next, bi0, next0);
1341 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1344 errors = session_manager_flush_enqueue_events (my_thread_index);
1345 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1347 return from_frame->n_vectors;
1351 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1352 vlib_frame_t * from_frame)
1354 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1358 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1359 vlib_frame_t * from_frame)
1361 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1365 VLIB_REGISTER_NODE (tcp4_established_node) =
1367 .function = tcp4_established,
1368 .name = "tcp4-established",
1369 /* Takes a vector of packets. */
1370 .vector_size = sizeof (u32),
1371 .n_errors = TCP_N_ERROR,
1372 .error_strings = tcp_error_strings,
1373 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1376 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1377 foreach_tcp_state_next
1380 .format_trace = format_tcp_rx_trace_short,
1384 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1387 VLIB_REGISTER_NODE (tcp6_established_node) =
1389 .function = tcp6_established,
1390 .name = "tcp6-established",
1391 /* Takes a vector of packets. */
1392 .vector_size = sizeof (u32),
1393 .n_errors = TCP_N_ERROR,
1394 .error_strings = tcp_error_strings,
1395 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1398 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1399 foreach_tcp_state_next
1402 .format_trace = format_tcp_rx_trace_short,
1407 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1409 vlib_node_registration_t tcp4_syn_sent_node;
1410 vlib_node_registration_t tcp6_syn_sent_node;
1413 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1414 vlib_frame_t * from_frame, int is_ip4)
1416 tcp_main_t *tm = vnet_get_tcp_main ();
1417 u32 n_left_from, next_index, *from, *to_next;
1418 u32 my_thread_index = vm->thread_index, errors = 0;
1419 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
1421 from = vlib_frame_vector_args (from_frame);
1422 n_left_from = from_frame->n_vectors;
1424 next_index = node->cached_next_index;
1426 while (n_left_from > 0)
1430 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1432 while (n_left_from > 0 && n_left_to_next > 0)
1434 u32 bi0, ack0, seq0;
1437 tcp_header_t *tcp0 = 0;
1438 tcp_connection_t *tc0;
1439 tcp_connection_t *new_tc0;
1440 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1447 n_left_to_next -= 1;
1449 b0 = vlib_get_buffer (vm, bi0);
1451 tcp_half_open_connection_get (vnet_buffer (b0)->
1452 tcp.connection_index);
1454 ack0 = vnet_buffer (b0)->tcp.ack_number;
1455 seq0 = vnet_buffer (b0)->tcp.seq_number;
1456 tcp0 = tcp_buffer_hdr (b0);
1459 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1462 /* SYNs, FINs and data consume sequence numbers */
1463 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1464 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
1467 * 1. check the ACK bit
1471 * If the ACK bit is set
1472 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
1473 * the RST bit is set, if so drop the segment and return)
1474 * <SEQ=SEG.ACK><CTL=RST>
1475 * and discard the segment. Return.
1476 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
1480 if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt)
1482 if (!tcp_rst (tcp0))
1483 tcp_send_reset (b0, is_ip4);
1488 /* Make sure ACK is valid */
1489 if (tc0->snd_una > ack0)
1494 * 2. check the RST bit
1499 /* If ACK is acceptable, signal client that peer is not
1500 * willing to accept connection and drop connection*/
1503 stream_session_connect_notify (&tc0->connection, sst,
1505 tcp_connection_cleanup (tc0);
1511 * 3. check the security and precedence (skipped)
1515 * 4. check the SYN bit
1518 /* No SYN flag. Drop. */
1519 if (!tcp_syn (tcp0))
1522 /* Stop connection establishment and retransmit timers */
1523 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
1524 tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT_SYN);
1526 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
1527 * current thread pool. */
1528 pool_get (tm->connections[my_thread_index], new_tc0);
1529 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
1531 new_tc0->c_thread_index = my_thread_index;
1533 /* Cleanup half-open connection XXX lock */
1534 pool_put (tm->half_open_connections, tc0);
1536 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
1537 new_tc0->irs = seq0;
1540 tcp_options_parse (tcp0, &new_tc0->opt);
1542 if (tcp_opts_tstamp (&new_tc0->opt))
1544 new_tc0->tsval_recent = new_tc0->opt.tsval;
1545 new_tc0->tsval_recent_age = tcp_time_now ();
1548 if (tcp_opts_wscale (&new_tc0->opt))
1549 new_tc0->snd_wscale = new_tc0->opt.wscale;
1552 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
1553 new_tc0->snd_wl1 = seq0;
1554 new_tc0->snd_wl2 = ack0;
1556 tcp_connection_init_vars (new_tc0);
1558 /* SYN-ACK: See if we can switch to ESTABLISHED state */
1561 /* Our SYN is ACKed: we have iss < ack = snd_una */
1563 /* TODO Dequeue acknowledged segments if we support Fast Open */
1564 new_tc0->snd_una = ack0;
1565 new_tc0->state = TCP_STATE_ESTABLISHED;
1567 /* Make sure las is initialized for the wnd computation */
1568 new_tc0->rcv_las = new_tc0->rcv_nxt;
1570 /* Notify app that we have connection */
1571 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1573 stream_session_init_fifos_pointers (&new_tc0->connection,
1576 /* Make sure after data segment processing ACK is sent */
1577 new_tc0->flags |= TCP_CONN_SNDACK;
1579 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
1582 new_tc0->state = TCP_STATE_SYN_RCVD;
1584 /* Notify app that we have connection */
1585 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1586 stream_session_init_fifos_pointers (&new_tc0->connection,
1589 tcp_make_synack (new_tc0, b0);
1590 next0 = tcp_next_output (is_ip4);
1595 /* Read data, if any */
1596 if (vnet_buffer (b0)->tcp.data_len)
1598 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1599 error0 = tcp_segment_rcv (tm, new_tc0, b0,
1600 vnet_buffer (b0)->tcp.data_len,
1602 if (error0 == TCP_ERROR_PURE_ACK)
1603 error0 = TCP_ERROR_SYN_ACKS_RCVD;
1607 tcp_make_ack (new_tc0, b0);
1608 next0 = tcp_next_output (new_tc0->c_is_ip4);
1613 b0->error = error0 ? node->errors[error0] : 0;
1614 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1616 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1617 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
1618 clib_memcpy (&t0->tcp_connection, tc0,
1619 sizeof (t0->tcp_connection));
1622 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1623 n_left_to_next, bi0, next0);
1626 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1629 errors = session_manager_flush_enqueue_events (my_thread_index);
1633 vlib_node_increment_counter (vm, tcp4_established_node.index,
1634 TCP_ERROR_EVENT_FIFO_FULL, errors);
1636 vlib_node_increment_counter (vm, tcp6_established_node.index,
1637 TCP_ERROR_EVENT_FIFO_FULL, errors);
1640 return from_frame->n_vectors;
1644 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
1645 vlib_frame_t * from_frame)
1647 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1651 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
1652 vlib_frame_t * from_frame)
1654 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1658 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
1660 .function = tcp4_syn_sent,
1661 .name = "tcp4-syn-sent",
1662 /* Takes a vector of packets. */
1663 .vector_size = sizeof (u32),
1664 .n_errors = TCP_N_ERROR,
1665 .error_strings = tcp_error_strings,
1666 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1669 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1670 foreach_tcp_state_next
1673 .format_trace = format_tcp_rx_trace_short,
1677 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
1680 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
1682 .function = tcp6_syn_sent_rcv,
1683 .name = "tcp6-syn-sent",
1684 /* Takes a vector of packets. */
1685 .vector_size = sizeof (u32),
1686 .n_errors = TCP_N_ERROR,
1687 .error_strings = tcp_error_strings,
1688 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1691 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1692 foreach_tcp_state_next
1695 .format_trace = format_tcp_rx_trace_short,
1699 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
1701 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
1702 * as per RFC793 p. 64
1705 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1706 vlib_frame_t * from_frame, int is_ip4)
1708 tcp_main_t *tm = vnet_get_tcp_main ();
1709 u32 n_left_from, next_index, *from, *to_next;
1710 u32 my_thread_index = vm->thread_index, errors = 0;
1712 from = vlib_frame_vector_args (from_frame);
1713 n_left_from = from_frame->n_vectors;
1715 next_index = node->cached_next_index;
1717 while (n_left_from > 0)
1721 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1723 while (n_left_from > 0 && n_left_to_next > 0)
1727 tcp_header_t *tcp0 = 0;
1728 tcp_connection_t *tc0;
1729 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1736 n_left_to_next -= 1;
1738 b0 = vlib_get_buffer (vm, bi0);
1739 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1741 if (PREDICT_FALSE (tc0 == 0))
1743 error0 = TCP_ERROR_INVALID_CONNECTION;
1747 tcp0 = tcp_buffer_hdr (b0);
1749 /* SYNs, FINs and data consume sequence numbers */
1750 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1751 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0)
1752 + vnet_buffer (b0)->tcp.data_len;
1755 * Special treatment for CLOSED
1759 case TCP_STATE_CLOSED:
1765 * For all other states (except LISTEN)
1768 /* 1-4: check SEQ, RST, SYN */
1770 (tcp_segment_validate (vm, tc0, b0, tcp0, &next0)))
1772 error0 = TCP_ERROR_SEGMENT_INVALID;
1776 /* 5: check the ACK field */
1779 case TCP_STATE_SYN_RCVD:
1781 * If the segment acknowledgment is not acceptable, form a
1783 * <SEQ=SEG.ACK><CTL=RST>
1786 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
1788 tcp_send_reset (b0, is_ip4);
1792 /* Update rtt and rto */
1793 tc0->bytes_acked = 1;
1794 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
1796 /* Switch state to ESTABLISHED */
1797 tc0->state = TCP_STATE_ESTABLISHED;
1799 /* Initialize session variables */
1800 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
1801 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
1803 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
1804 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
1806 /* Shoulder tap the server */
1807 stream_session_accept_notify (&tc0->connection);
1809 /* Reset SYN-ACK retransmit timer */
1810 tcp_retransmit_timer_reset (tc0);
1812 case TCP_STATE_ESTABLISHED:
1813 /* We can get packets in established state here because they
1814 * were enqueued before state change */
1815 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1819 case TCP_STATE_FIN_WAIT_1:
1820 /* In addition to the processing for the ESTABLISHED state, if
1821 * our FIN is now acknowledged then enter FIN-WAIT-2 and
1822 * continue processing in that state. */
1823 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1826 /* If FIN is ACKed */
1827 if (tc0->snd_una == tc0->snd_una_max)
1829 tc0->state = TCP_STATE_FIN_WAIT_2;
1830 /* Stop all timers, 2MSL will be set lower */
1831 tcp_connection_timers_reset (tc0);
1834 case TCP_STATE_FIN_WAIT_2:
1835 /* In addition to the processing for the ESTABLISHED state, if
1836 * the retransmission queue is empty, the user's CLOSE can be
1837 * acknowledged ("ok") but do not delete the TCB. */
1838 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1840 /* check if rtx queue is empty and ack CLOSE TODO */
1842 case TCP_STATE_CLOSE_WAIT:
1843 /* Do the same processing as for the ESTABLISHED state. */
1844 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1847 case TCP_STATE_CLOSING:
1848 /* In addition to the processing for the ESTABLISHED state, if
1849 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
1850 * otherwise ignore the segment. */
1851 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1854 /* XXX test that send queue empty */
1855 tc0->state = TCP_STATE_TIME_WAIT;
1859 case TCP_STATE_LAST_ACK:
1860 /* The only thing that can arrive in this state is an
1861 * acknowledgment of our FIN. If our FIN is now acknowledged,
1862 * delete the TCB, enter the CLOSED state, and return. */
1864 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
1867 tc0->state = TCP_STATE_CLOSED;
1869 /* Don't delete the connection/session yet. Instead, wait a
1870 * reasonable amount of time until the pipes are cleared. In
1871 * particular, this makes sure that we won't have dead sessions
1872 * when processing events on the tx path */
1873 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
1875 /* Stop retransmit */
1876 tcp_retransmit_timer_reset (tc0);
1881 case TCP_STATE_TIME_WAIT:
1882 /* The only thing that can arrive in this state is a
1883 * retransmission of the remote FIN. Acknowledge it, and restart
1884 * the 2 MSL timeout. */
1893 /* 6: check the URG bit TODO */
1895 /* 7: process the segment text */
1898 case TCP_STATE_ESTABLISHED:
1899 case TCP_STATE_FIN_WAIT_1:
1900 case TCP_STATE_FIN_WAIT_2:
1901 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1902 error0 = tcp_segment_rcv (tm, tc0, b0,
1903 vnet_buffer (b0)->tcp.data_len,
1906 case TCP_STATE_CLOSE_WAIT:
1907 case TCP_STATE_CLOSING:
1908 case TCP_STATE_LAST_ACK:
1909 case TCP_STATE_TIME_WAIT:
1910 /* This should not occur, since a FIN has been received from the
1911 * remote side. Ignore the segment text. */
1915 /* 8: check the FIN bit */
1916 if (!tcp_fin (tcp0))
1921 case TCP_STATE_ESTABLISHED:
1922 case TCP_STATE_SYN_RCVD:
1923 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
1924 tcp_connection_timers_reset (tc0);
1925 tcp_make_fin (tc0, b0);
1926 next0 = tcp_next_output (tc0->c_is_ip4);
1927 stream_session_disconnect_notify (&tc0->connection);
1928 tc0->state = TCP_STATE_CLOSE_WAIT;
1930 case TCP_STATE_CLOSE_WAIT:
1931 case TCP_STATE_CLOSING:
1932 case TCP_STATE_LAST_ACK:
1935 case TCP_STATE_FIN_WAIT_1:
1936 tc0->state = TCP_STATE_TIME_WAIT;
1937 tcp_connection_timers_reset (tc0);
1938 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
1940 case TCP_STATE_FIN_WAIT_2:
1941 /* Got FIN, send ACK! */
1942 tc0->state = TCP_STATE_TIME_WAIT;
1943 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1944 tcp_make_ack (tc0, b0);
1945 next0 = tcp_next_output (is_ip4);
1947 case TCP_STATE_TIME_WAIT:
1948 /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
1951 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
1954 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1957 b0->error = error0 ? node->errors[error0] : 0;
1959 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1961 tcp_rx_trace_t *t0 =
1962 vlib_add_trace (vm, node, b0, sizeof (*t0));
1963 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
1966 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1967 n_left_to_next, bi0, next0);
1970 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1973 errors = session_manager_flush_enqueue_events (my_thread_index);
1977 vlib_node_increment_counter (vm, tcp4_established_node.index,
1978 TCP_ERROR_EVENT_FIFO_FULL, errors);
1980 vlib_node_increment_counter (vm, tcp6_established_node.index,
1981 TCP_ERROR_EVENT_FIFO_FULL, errors);
1984 return from_frame->n_vectors;
1988 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
1989 vlib_frame_t * from_frame)
1991 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1995 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
1996 vlib_frame_t * from_frame)
1998 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2002 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2004 .function = tcp4_rcv_process,
2005 .name = "tcp4-rcv-process",
2006 /* Takes a vector of packets. */
2007 .vector_size = sizeof (u32),
2008 .n_errors = TCP_N_ERROR,
2009 .error_strings = tcp_error_strings,
2010 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2013 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2014 foreach_tcp_state_next
2017 .format_trace = format_tcp_rx_trace_short,
2021 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2024 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2026 .function = tcp6_rcv_process,
2027 .name = "tcp6-rcv-process",
2028 /* Takes a vector of packets. */
2029 .vector_size = sizeof (u32),
2030 .n_errors = TCP_N_ERROR,
2031 .error_strings = tcp_error_strings,
2032 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2035 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2036 foreach_tcp_state_next
2039 .format_trace = format_tcp_rx_trace_short,
2043 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2045 vlib_node_registration_t tcp4_listen_node;
2046 vlib_node_registration_t tcp6_listen_node;
2049 * LISTEN state processing as per RFC 793 p. 65
2052 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2053 vlib_frame_t * from_frame, int is_ip4)
2055 u32 n_left_from, next_index, *from, *to_next;
2056 u32 my_thread_index = vm->thread_index;
2057 tcp_main_t *tm = vnet_get_tcp_main ();
2058 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
2060 from = vlib_frame_vector_args (from_frame);
2061 n_left_from = from_frame->n_vectors;
2063 next_index = node->cached_next_index;
2065 while (n_left_from > 0)
2069 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2071 while (n_left_from > 0 && n_left_to_next > 0)
2076 tcp_header_t *th0 = 0;
2077 tcp_connection_t *lc0;
2080 tcp_connection_t *child0;
2081 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2088 n_left_to_next -= 1;
2090 b0 = vlib_get_buffer (vm, bi0);
2091 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2095 ip40 = vlib_buffer_get_current (b0);
2096 th0 = ip4_next_header (ip40);
2100 ip60 = vlib_buffer_get_current (b0);
2101 th0 = ip6_next_header (ip60);
2104 /* Create child session. For syn-flood protection use filter */
2106 /* 1. first check for an RST */
2110 /* 2. second check for an ACK */
2113 tcp_send_reset (b0, is_ip4);
2117 /* 3. check for a SYN (did that already) */
2119 /* Create child session and send SYN-ACK */
2120 pool_get (tm->connections[my_thread_index], child0);
2121 memset (child0, 0, sizeof (*child0));
2123 child0->c_c_index = child0 - tm->connections[my_thread_index];
2124 child0->c_lcl_port = lc0->c_lcl_port;
2125 child0->c_rmt_port = th0->src_port;
2126 child0->c_is_ip4 = is_ip4;
2127 child0->c_thread_index = my_thread_index;
2131 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2132 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2136 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2137 sizeof (ip6_address_t));
2138 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2139 sizeof (ip6_address_t));
2142 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2145 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2149 tcp_options_parse (th0, &child0->opt);
2151 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2152 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2153 child0->rcv_las = child0->rcv_nxt;
2154 child0->state = TCP_STATE_SYN_RCVD;
2156 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2157 * segments are used to initialize PAWS. */
2158 if (tcp_opts_tstamp (&child0->opt))
2160 child0->tsval_recent = child0->opt.tsval;
2161 child0->tsval_recent_age = tcp_time_now ();
2164 if (tcp_opts_wscale (&child0->opt))
2165 child0->snd_wscale = child0->opt.wscale;
2168 child0->snd_wnd = clib_net_to_host_u16 (th0->window);
2169 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2170 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2172 tcp_connection_init_vars (child0);
2174 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0);
2176 /* Reuse buffer to make syn-ack and send */
2177 tcp_make_synack (child0, b0);
2178 next0 = tcp_next_output (is_ip4);
2180 /* Init fifo pointers after we have iss */
2181 stream_session_init_fifos_pointers (&child0->connection,
2185 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2187 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2188 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2189 clib_memcpy (&t0->tcp_connection, lc0,
2190 sizeof (t0->tcp_connection));
2193 b0->error = node->errors[error0];
2195 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2196 n_left_to_next, bi0, next0);
2199 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2201 return from_frame->n_vectors;
2205 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2206 vlib_frame_t * from_frame)
2208 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2212 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2213 vlib_frame_t * from_frame)
2215 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2219 VLIB_REGISTER_NODE (tcp4_listen_node) =
2221 .function = tcp4_listen,
2222 .name = "tcp4-listen",
2223 /* Takes a vector of packets. */
2224 .vector_size = sizeof (u32),
2225 .n_errors = TCP_N_ERROR,
2226 .error_strings = tcp_error_strings,
2227 .n_next_nodes = TCP_LISTEN_N_NEXT,
2230 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2231 foreach_tcp_state_next
2234 .format_trace = format_tcp_rx_trace_short,
2238 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2241 VLIB_REGISTER_NODE (tcp6_listen_node) =
2243 .function = tcp6_listen,
2244 .name = "tcp6-listen",
2245 /* Takes a vector of packets. */
2246 .vector_size = sizeof (u32),
2247 .n_errors = TCP_N_ERROR,
2248 .error_strings = tcp_error_strings,
2249 .n_next_nodes = TCP_LISTEN_N_NEXT,
2252 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2253 foreach_tcp_state_next
2256 .format_trace = format_tcp_rx_trace_short,
2260 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2262 vlib_node_registration_t tcp4_input_node;
2263 vlib_node_registration_t tcp6_input_node;
2265 typedef enum _tcp_input_next
2267 TCP_INPUT_NEXT_DROP,
2268 TCP_INPUT_NEXT_LISTEN,
2269 TCP_INPUT_NEXT_RCV_PROCESS,
2270 TCP_INPUT_NEXT_SYN_SENT,
2271 TCP_INPUT_NEXT_ESTABLISHED,
2272 TCP_INPUT_NEXT_RESET,
2276 #define foreach_tcp4_input_next \
2277 _ (DROP, "error-drop") \
2278 _ (LISTEN, "tcp4-listen") \
2279 _ (RCV_PROCESS, "tcp4-rcv-process") \
2280 _ (SYN_SENT, "tcp4-syn-sent") \
2281 _ (ESTABLISHED, "tcp4-established") \
2282 _ (RESET, "tcp4-reset")
2284 #define foreach_tcp6_input_next \
2285 _ (DROP, "error-drop") \
2286 _ (LISTEN, "tcp6-listen") \
2287 _ (RCV_PROCESS, "tcp6-rcv-process") \
2288 _ (SYN_SENT, "tcp6-syn-sent") \
2289 _ (ESTABLISHED, "tcp6-established") \
2290 _ (RESET, "tcp6-reset")
2292 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2295 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2296 vlib_frame_t * from_frame, int is_ip4)
2298 u32 n_left_from, next_index, *from, *to_next;
2299 u32 my_thread_index = vm->thread_index;
2300 tcp_main_t *tm = vnet_get_tcp_main ();
2302 from = vlib_frame_vector_args (from_frame);
2303 n_left_from = from_frame->n_vectors;
2305 next_index = node->cached_next_index;
2307 while (n_left_from > 0)
2311 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2313 while (n_left_from > 0 && n_left_to_next > 0)
2315 int n_advance_bytes0, n_data_bytes0;
2318 tcp_header_t *tcp0 = 0;
2319 tcp_connection_t *tc0;
2322 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2330 n_left_to_next -= 1;
2332 b0 = vlib_get_buffer (vm, bi0);
2333 vnet_buffer (b0)->tcp.flags = 0;
2335 /* Checksum computed by ipx_local no need to compute again */
2339 ip40 = vlib_buffer_get_current (b0);
2340 tcp0 = ip4_next_header (ip40);
2341 n_advance_bytes0 = (ip4_header_bytes (ip40)
2342 + tcp_header_bytes (tcp0));
2343 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2346 /* lookup session */
2348 (tcp_connection_t *)
2349 stream_session_lookup_transport4 (&ip40->dst_address,
2353 SESSION_TYPE_IP4_TCP,
2358 ip60 = vlib_buffer_get_current (b0);
2359 tcp0 = ip6_next_header (ip60);
2360 n_advance_bytes0 = tcp_header_bytes (tcp0);
2361 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2363 n_advance_bytes0 += sizeof (ip60[0]);
2366 (tcp_connection_t *)
2367 stream_session_lookup_transport6 (&ip60->src_address,
2371 SESSION_TYPE_IP6_TCP,
2376 if (PREDICT_FALSE (n_advance_bytes0 < 0))
2378 error0 = TCP_ERROR_LENGTH;
2382 /* Session exists */
2383 if (PREDICT_TRUE (0 != tc0))
2385 /* Save connection index */
2386 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2387 vnet_buffer (b0)->tcp.seq_number =
2388 clib_net_to_host_u32 (tcp0->seq_number);
2389 vnet_buffer (b0)->tcp.ack_number =
2390 clib_net_to_host_u32 (tcp0->ack_number);
2392 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
2393 - (u8 *) vlib_buffer_get_current (b0);
2394 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
2395 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
2397 flags0 = tcp0->flags & filter_flags;
2398 next0 = tm->dispatch_table[tc0->state][flags0].next;
2399 error0 = tm->dispatch_table[tc0->state][flags0].error;
2401 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH))
2403 tcp_state_t state0 = tc0->state;
2404 /* Overload tcp flags to store state */
2405 vnet_buffer (b0)->tcp.flags = tc0->state;
2406 clib_warning ("disp error state %U flags %U",
2407 format_tcp_state, &state0,
2408 format_tcp_flags, (int) flags0);
2414 next0 = TCP_INPUT_NEXT_RESET;
2415 error0 = TCP_ERROR_NO_LISTENER;
2419 b0->error = error0 ? node->errors[error0] : 0;
2421 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2423 tcp_rx_trace_t *t0 =
2424 vlib_add_trace (vm, node, b0, sizeof (*t0));
2425 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2428 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2429 n_left_to_next, bi0, next0);
2432 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2435 return from_frame->n_vectors;
2439 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2440 vlib_frame_t * from_frame)
2442 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2446 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2447 vlib_frame_t * from_frame)
2449 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2453 VLIB_REGISTER_NODE (tcp4_input_node) =
2455 .function = tcp4_input,
2456 .name = "tcp4-input",
2457 /* Takes a vector of packets. */
2458 .vector_size = sizeof (u32),
2459 .n_errors = TCP_N_ERROR,
2460 .error_strings = tcp_error_strings,
2461 .n_next_nodes = TCP_INPUT_N_NEXT,
2464 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2465 foreach_tcp4_input_next
2468 .format_buffer = format_tcp_header,
2469 .format_trace = format_tcp_rx_trace,
2473 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
2476 VLIB_REGISTER_NODE (tcp6_input_node) =
2478 .function = tcp6_input,
2479 .name = "tcp6-input",
2480 /* Takes a vector of packets. */
2481 .vector_size = sizeof (u32),
2482 .n_errors = TCP_N_ERROR,
2483 .error_strings = tcp_error_strings,
2484 .n_next_nodes = TCP_INPUT_N_NEXT,
2487 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2488 foreach_tcp6_input_next
2491 .format_buffer = format_tcp_header,
2492 .format_trace = format_tcp_rx_trace,
2496 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
2499 tcp_dispatch_table_init (tcp_main_t * tm)
2502 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
2503 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
2505 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
2506 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
2509 #define _(t,f,n,e) \
2511 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
2512 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
2515 /* SYNs for new connections -> tcp-listen. */
2516 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
2517 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
2518 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2519 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2520 /* SYN-ACK for a SYN */
2521 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2523 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2524 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2525 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2527 /* ACK for for established connection -> tcp-established. */
2528 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2529 /* FIN for for established connection -> tcp-established. */
2530 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2531 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2533 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2534 /* ACK or FIN-ACK to our FIN */
2535 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2536 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
2538 /* FIN in reply to our FIN from the other side */
2539 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2540 /* FIN confirming that the peer (app) has closed */
2541 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2542 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2544 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2545 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
2550 tcp_input_init (vlib_main_t * vm)
2552 clib_error_t *error = 0;
2553 tcp_main_t *tm = vnet_get_tcp_main ();
2555 if ((error = vlib_call_init_function (vm, tcp_init)))
2558 /* Initialize dispatch table. */
2559 tcp_dispatch_table_init (tm);
2564 VLIB_INIT_FUNCTION (tcp_input_init);
2567 * fd.io coding-style-patch-verification: ON
2570 * eval: (c-set-style "gnu")