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_seq && seq_gt (ack, tc->rtt_seq) && !tc->rto_boff)
397 mrtt = tcp_time_now () - tc->rtt_ts;
400 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
401 * snd_una, i.e., the left side of the send window:
402 * seq_lt (tc->snd_una, ack). Note: last condition could be dropped, we don't
403 * try to update rtt for dupacks */
404 else if (tcp_opts_tstamp (&tc->opt) && tc->opt.tsecr && tc->bytes_acked)
406 mrtt = tcp_time_now () - tc->opt.tsecr;
409 /* Ignore dubious measurements */
410 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
413 tcp_estimate_rtt (tc, mrtt);
415 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
417 /* Allow measuring of RTT and make sure boff is 0 */
425 * Dequeue bytes that have been acked and while at it update RTT estimates.
428 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
430 /* Dequeue the newly ACKed bytes */
431 stream_session_dequeue_drop (&tc->connection, tc->bytes_acked);
433 /* Update rtt and rto */
434 tcp_update_rtt (tc, ack);
438 * Check if dupack as per RFC5681 Sec. 2
440 * This works only if called before updating snd_wnd.
443 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 new_snd_wnd)
445 return ((vnet_buffer (b)->tcp.ack_number == tc->snd_una)
446 && seq_gt (tc->snd_una_max, tc->snd_una)
447 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
448 && (new_snd_wnd == tc->snd_wnd));
452 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
454 sack_scoreboard_hole_t *next, *prev;
456 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
458 next = pool_elt_at_index (sb->holes, hole->next);
459 next->prev = hole->prev;
462 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
464 prev = pool_elt_at_index (sb->holes, hole->prev);
465 prev->next = hole->next;
469 sb->head = hole->next;
472 pool_put (sb->holes, hole);
475 sack_scoreboard_hole_t *
476 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
479 sack_scoreboard_hole_t *hole, *next, *prev;
482 pool_get (sb->holes, hole);
483 memset (hole, 0, sizeof (*hole));
487 hole_index = hole - sb->holes;
489 prev = scoreboard_get_hole (sb, prev_index);
492 hole->prev = prev - sb->holes;
493 hole->next = prev->next;
495 if ((next = scoreboard_next_hole (sb, hole)))
496 next->prev = hole_index;
498 prev->next = hole_index;
502 sb->head = hole_index;
503 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
504 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
511 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
513 sack_scoreboard_t *sb = &tc->sack_sb;
514 sack_block_t *blk, tmp;
515 sack_scoreboard_hole_t *hole, *next_hole, *last_hole, *new_hole;
516 u32 blk_index = 0, old_sacked_bytes, hole_index;
519 sb->last_sacked_bytes = 0;
521 old_sacked_bytes = sb->sacked_bytes;
523 if (!tcp_opts_sack (&tc->opt) && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
526 /* Remove invalid blocks */
528 while (blk < vec_end (tc->opt.sacks))
530 if (seq_lt (blk->start, blk->end)
531 && seq_gt (blk->start, tc->snd_una)
532 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_nxt))
537 vec_del1 (tc->opt.sacks, blk - tc->opt.sacks);
540 /* Add block for cumulative ack */
541 if (seq_gt (ack, tc->snd_una))
543 tmp.start = tc->snd_una;
545 vec_add1 (tc->opt.sacks, tmp);
548 if (vec_len (tc->opt.sacks) == 0)
551 /* Make sure blocks are ordered */
552 for (i = 0; i < vec_len (tc->opt.sacks); i++)
553 for (j = i + 1; j < vec_len (tc->opt.sacks); j++)
554 if (seq_lt (tc->opt.sacks[j].start, tc->opt.sacks[i].start))
556 tmp = tc->opt.sacks[i];
557 tc->opt.sacks[i] = tc->opt.sacks[j];
558 tc->opt.sacks[j] = tmp;
561 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
563 /* If no holes, insert the first that covers all outstanding bytes */
564 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
565 tc->snd_una, tc->snd_una_max);
566 sb->tail = scoreboard_hole_index (sb, last_hole);
570 /* If we have holes but snd_una_max is beyond the last hole, update
572 tmp = tc->opt.sacks[vec_len (tc->opt.sacks) - 1];
573 last_hole = scoreboard_last_hole (sb);
574 if (seq_gt (tc->snd_una_max, sb->max_byte_sacked)
575 && seq_gt (tc->snd_una_max, last_hole->end))
576 last_hole->end = tc->snd_una_max;
579 /* Walk the holes with the SACK blocks */
580 hole = pool_elt_at_index (sb->holes, sb->head);
581 while (hole && blk_index < vec_len (tc->opt.sacks))
583 blk = &tc->opt.sacks[blk_index];
585 if (seq_leq (blk->start, hole->start))
587 /* Block covers hole. Remove hole */
588 if (seq_geq (blk->end, hole->end))
590 next_hole = scoreboard_next_hole (sb, hole);
592 /* Byte accounting */
593 if (seq_leq (hole->end, ack))
595 /* Bytes lost because snd_wnd left edge advances */
596 if (next_hole && seq_leq (next_hole->start, ack))
597 sb->sacked_bytes -= next_hole->start - hole->end;
599 sb->sacked_bytes -= ack - hole->end;
603 sb->sacked_bytes += scoreboard_hole_bytes (hole);
606 /* snd_una needs to be advanced */
607 if (seq_geq (ack, hole->end))
609 if (next_hole && seq_lt (ack, next_hole->start))
610 sb->snd_una_adv = next_hole->start - ack;
612 sb->snd_una_adv = sb->max_byte_sacked - ack;
614 /* all these can be delivered */
615 sb->sacked_bytes -= sb->snd_una_adv;
618 /* About to remove last hole */
619 if (hole == last_hole)
621 sb->tail = hole->prev;
622 last_hole = scoreboard_last_hole (sb);
623 /* keep track of max byte sacked in case the last hole
625 if (seq_gt (hole->end, sb->max_byte_sacked))
626 sb->max_byte_sacked = hole->end;
628 scoreboard_remove_hole (sb, hole);
631 /* Partial 'head' overlap */
634 if (seq_gt (blk->end, hole->start))
636 sb->sacked_bytes += blk->end - hole->start;
637 hole->start = blk->end;
644 /* Hole must be split */
645 if (seq_lt (blk->end, hole->end))
647 sb->sacked_bytes += blk->end - blk->start;
648 hole_index = scoreboard_hole_index (sb, hole);
649 new_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
652 /* Pool might've moved */
653 hole = scoreboard_get_hole (sb, hole_index);
654 hole->end = blk->start;
656 /* New or split of tail */
657 if ((last_hole->end == new_hole->end)
658 || seq_lt (last_hole->end, new_hole->start))
660 last_hole = new_hole;
661 sb->tail = scoreboard_hole_index (sb, new_hole);
665 hole = scoreboard_next_hole (sb, hole);
669 sb->sacked_bytes += hole->end - blk->start;
670 hole->end = blk->start;
671 hole = scoreboard_next_hole (sb, hole);
676 sb->last_sacked_bytes = sb->sacked_bytes + sb->snd_una_adv
682 * If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
683 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
685 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
687 if (seq_lt (tc->snd_wl1, seq)
688 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
690 tc->snd_wnd = snd_wnd;
693 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
695 /* Set probe timer if we just got 0 wnd */
696 if (tc->snd_wnd < tc->snd_mss
697 && !tcp_timer_is_active (tc, TCP_TIMER_PERSIST))
698 tcp_persist_timer_set (tc);
700 tcp_persist_timer_reset (tc);
705 tcp_cc_congestion (tcp_connection_t * tc)
707 tc->snd_congestion = tc->snd_nxt;
708 tc->cc_algo->congestion (tc);
709 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
713 tcp_cc_recover (tcp_connection_t * tc)
715 /* TODO: check if time to recover was small. It might be that RTO popped
719 tc->cc_algo->recovered (tc);
723 tc->snd_nxt = tc->snd_una;
725 tc->cc_algo->rcv_ack (tc);
726 tc->tsecr_last_ack = tc->opt.tsecr;
728 tcp_cong_recovery_off (tc);
730 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
734 tcp_cc_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b)
738 if (tcp_in_cong_recovery (tc))
740 partial_ack = seq_lt (tc->snd_una, tc->snd_congestion);
743 /* Clear retransmitted bytes. */
748 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
750 /* Clear retransmitted bytes. XXX should we clear all? */
752 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
754 /* In case snd_nxt is still in the past and output tries to
755 * shove some new bytes */
756 tc->snd_nxt = tc->snd_una_max;
758 /* XXX need proper RFC6675 support */
759 if (tc->sack_sb.last_sacked_bytes && !tcp_in_recovery (tc))
761 tcp_fast_retransmit (tc);
765 /* Retransmit first unacked segment */
766 tcp_retransmit_first_unacked (tc);
772 tc->cc_algo->rcv_ack (tc);
773 tc->tsecr_last_ack = tc->opt.tsecr;
779 tcp_cc_rcv_dupack (tcp_connection_t * tc, u32 ack)
781 // ASSERT (seq_geq(tc->snd_una, ack));
784 if (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
786 /* RFC6582 NewReno heuristic to avoid multiple fast retransmits */
787 if (tc->opt.tsecr != tc->tsecr_last_ack)
793 tcp_fastrecovery_on (tc);
795 /* Handle congestion and dupack */
796 tcp_cc_congestion (tc);
797 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
799 tcp_fast_retransmit (tc);
801 /* Post retransmit update cwnd to ssthresh and account for the
802 * three segments that have left the network and should've been
803 * buffered at the receiver */
804 tc->cwnd = tc->ssthresh + TCP_DUPACK_THRESHOLD * tc->snd_mss;
806 else if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD)
808 ASSERT (tcp_in_fastrecovery (tc));
810 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
815 tcp_cc_init (tcp_connection_t * tc)
817 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
818 tc->cc_algo->init (tc);
822 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
823 tcp_header_t * th, u32 * next, u32 * error)
827 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
828 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt))
830 /* If we have outstanding data and this is within the window, accept it,
831 * probably retransmit has timed out. Otherwise ACK segment and then
833 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
835 tcp_make_ack (tc, b);
836 *next = tcp_next_output (tc->c_is_ip4);
837 *error = TCP_ERROR_ACK_INVALID;
838 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
839 vnet_buffer (b)->tcp.ack_number);
843 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
844 vnet_buffer (b)->tcp.ack_number);
846 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
847 *error = TCP_ERROR_ACK_FUTURE;
850 /* If old ACK, probably it's an old dupack */
851 if (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
853 *error = TCP_ERROR_ACK_OLD;
854 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
855 vnet_buffer (b)->tcp.ack_number);
856 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
858 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
859 tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number);
865 if (tcp_opts_sack_permitted (&tc->opt))
866 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
868 new_snd_wnd = clib_net_to_host_u16 (th->window) << tc->snd_wscale;
870 if (tcp_ack_is_dupack (tc, b, new_snd_wnd))
872 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
873 tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number);
874 *error = TCP_ERROR_ACK_DUP;
882 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
883 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
885 /* Dequeue ACKed data and update RTT */
886 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
887 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
888 vnet_buffer (b)->tcp.ack_number, new_snd_wnd);
890 /* If some of our sent bytes have been acked, update cc and retransmit
894 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
896 /* Updates congestion control (slow start/congestion avoidance) */
897 tcp_cc_rcv_ack (tc, b);
899 /* If everything has been acked, stop retransmit timer
900 * otherwise update */
901 if (tc->snd_una == tc->snd_una_max)
902 tcp_retransmit_timer_reset (tc);
904 tcp_retransmit_timer_update (tc);
911 * Build SACK list as per RFC2018.
913 * Makes sure the first block contains the segment that generated the current
914 * ACK and the following ones are the ones most recently reported in SACK
917 * @param tc TCP connection for which the SACK list is updated
918 * @param start Start sequence number of the newest SACK block
919 * @param end End sequence of the newest SACK block
922 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
924 sack_block_t *new_list = 0, *block = 0;
927 /* If the first segment is ooo add it to the list. Last write might've moved
928 * rcv_nxt over the first segment. */
929 if (seq_lt (tc->rcv_nxt, start))
931 vec_add2 (new_list, block, 1);
932 block->start = start;
936 /* Find the blocks still worth keeping. */
937 for (i = 0; i < vec_len (tc->snd_sacks); i++)
939 /* Discard if rcv_nxt advanced beyond current block */
940 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
943 /* Merge or drop if segment overlapped by the new segment */
944 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
945 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
947 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
948 new_list[0].start = tc->snd_sacks[i].start;
949 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
950 new_list[0].end = tc->snd_sacks[i].end;
954 /* Save to new SACK list if we have space. */
955 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
957 vec_add1 (new_list, tc->snd_sacks[i]);
961 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
963 /* Replace old vector with new one */
964 vec_free (tc->snd_sacks);
965 tc->snd_sacks = new_list;
968 /** Enqueue data for delivery to application */
970 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
975 /* Pure ACK. Update rcv_nxt and be done. */
976 if (PREDICT_FALSE (data_len == 0))
978 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
979 return TCP_ERROR_PURE_ACK;
982 written = stream_session_enqueue_data (&tc->connection,
983 vlib_buffer_get_current (b),
984 data_len, 1 /* queue event */ );
986 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
989 if (PREDICT_TRUE (written == data_len))
991 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
993 /* If more data written than expected, account for out-of-order bytes. */
994 else if (written > data_len)
996 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end + written - data_len;
998 /* Send ACK confirming the update */
999 tc->flags |= TCP_CONN_SNDACK;
1001 else if (written > 0)
1003 /* We've written something but FIFO is probably full now */
1004 tc->rcv_nxt += written;
1006 /* Depending on how fast the app is, all remaining buffers in burst will
1007 * not be enqueued. Inform peer */
1008 tc->flags |= TCP_CONN_SNDACK;
1010 return TCP_ERROR_PARTIALLY_ENQUEUED;
1014 tc->flags |= TCP_CONN_SNDACK;
1015 return TCP_ERROR_FIFO_FULL;
1018 /* Update SACK list if need be */
1019 if (tcp_opts_sack_permitted (&tc->opt))
1021 /* Remove SACK blocks that have been delivered */
1022 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1025 return TCP_ERROR_ENQUEUED;
1028 /** Enqueue out-of-order data */
1030 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1033 stream_session_t *s0;
1036 /* Pure ACK. Do nothing */
1037 if (PREDICT_FALSE (data_len == 0))
1039 return TCP_ERROR_PURE_ACK;
1042 s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
1044 /* Enqueue out-of-order data with absolute offset */
1045 rv = svm_fifo_enqueue_with_offset (s0->server_rx_fifo,
1046 vnet_buffer (b)->tcp.seq_number,
1047 data_len, vlib_buffer_get_current (b));
1049 /* Nothing written */
1052 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1053 return TCP_ERROR_FIFO_FULL;
1056 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1058 /* Update SACK list if in use */
1059 if (tcp_opts_sack_permitted (&tc->opt))
1061 ooo_segment_t *newest;
1064 /* Get the newest segment from the fifo */
1065 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1066 start = ooo_segment_offset (s0->server_rx_fifo, newest);
1067 end = ooo_segment_end_offset (s0->server_rx_fifo, newest);
1069 tcp_update_sack_list (tc, start, end);
1072 return TCP_ERROR_ENQUEUED;
1076 * Check if ACK could be delayed. If ack can be delayed, it should return
1077 * true for a full frame. If we're always acking return 0.
1080 tcp_can_delack (tcp_connection_t * tc)
1082 /* Send ack if ... */
1084 /* just sent a rcv wnd 0 */
1085 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1086 /* constrained to send ack */
1087 || (tc->flags & TCP_CONN_SNDACK) != 0
1088 /* we're almost out of tx wnd */
1089 || tcp_available_snd_space (tc) < 2 * tc->snd_mss)
1096 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1097 u16 n_data_bytes, u32 * next0)
1101 /* Handle out-of-order data */
1102 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1104 /* Old sequence numbers allowed through because they overlapped
1107 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1109 error = TCP_ERROR_SEGMENT_OLD;
1110 *next0 = TCP_NEXT_DROP;
1114 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1116 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1117 * cwnd on remote peer when congested 2) acks leaving should have the
1118 * latest rcv_wnd since the burst may eaten up all of it, so only the
1119 * old ones could be filtered.
1122 /* RFC2581: Send DUPACK for fast retransmit */
1123 tcp_make_ack (tc, b);
1124 *next0 = tcp_next_output (tc->c_is_ip4);
1126 /* Mark as DUPACK. We may filter these in output if
1127 * the burst fills the holes. */
1129 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1131 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1135 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1136 * segments can be enqueued after fifo tail offset changes. */
1137 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1139 if (n_data_bytes == 0)
1141 *next0 = TCP_NEXT_DROP;
1145 /* Check if ACK can be delayed */
1146 if (tcp_can_delack (tc))
1148 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1149 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1153 *next0 = tcp_next_output (tc->c_is_ip4);
1154 tcp_make_ack (tc, b);
1162 tcp_header_t tcp_header;
1163 tcp_connection_t tcp_connection;
1167 format_tcp_rx_trace (u8 * s, va_list * args)
1169 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1170 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1171 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1172 uword indent = format_get_indent (s);
1174 s = format (s, "%U\n%U%U",
1175 format_tcp_header, &t->tcp_header, 128,
1176 format_white_space, indent,
1177 format_tcp_connection_verbose, &t->tcp_connection);
1183 format_tcp_rx_trace_short (u8 * s, va_list * args)
1185 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1186 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1187 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1189 s = format (s, "%d -> %d (%U)",
1190 clib_net_to_host_u16 (t->tcp_header.src_port),
1191 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1192 &t->tcp_connection.state);
1198 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1199 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1203 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1207 th0 = tcp_buffer_hdr (b0);
1209 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1213 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1215 if (PREDICT_TRUE (!val))
1219 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1221 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1225 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1226 vlib_frame_t * from_frame, int is_ip4)
1228 u32 n_left_from, next_index, *from, *to_next;
1229 u32 my_thread_index = vm->thread_index, errors = 0;
1230 tcp_main_t *tm = vnet_get_tcp_main ();
1233 from = vlib_frame_vector_args (from_frame);
1234 n_left_from = from_frame->n_vectors;
1236 next_index = node->cached_next_index;
1238 while (n_left_from > 0)
1242 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1244 while (n_left_from > 0 && n_left_to_next > 0)
1248 tcp_header_t *th0 = 0;
1249 tcp_connection_t *tc0;
1250 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1257 n_left_to_next -= 1;
1259 b0 = vlib_get_buffer (vm, bi0);
1260 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1263 if (PREDICT_FALSE (tc0 == 0))
1265 error0 = TCP_ERROR_INVALID_CONNECTION;
1269 th0 = tcp_buffer_hdr (b0);
1271 is_fin = (th0->flags & TCP_FLAG_FIN) != 0;
1273 /* SYNs, FINs and data consume sequence numbers */
1274 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1275 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1277 /* TODO header prediction fast path */
1279 /* 1-4: check SEQ, RST, SYN */
1280 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1282 error0 = TCP_ERROR_SEGMENT_INVALID;
1283 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1284 vnet_buffer (b0)->tcp.seq_number,
1285 vnet_buffer (b0)->tcp.seq_end);
1289 /* 5: check the ACK field */
1290 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1295 /* 6: check the URG bit TODO */
1297 /* 7: process the segment text */
1299 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1300 error0 = tcp_segment_rcv (tm, tc0, b0,
1301 vnet_buffer (b0)->tcp.data_len, &next0);
1303 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1304 * dangling reference. */
1306 /* 8: check the FIN bit */
1309 /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
1310 * wait for session to call close. To avoid lingering
1311 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1312 tc0->state = TCP_STATE_CLOSE_WAIT;
1313 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1314 stream_session_disconnect_notify (&tc0->connection);
1315 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1319 b0->error = node->errors[error0];
1320 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1322 tcp_rx_trace_t *t0 =
1323 vlib_add_trace (vm, node, b0, sizeof (*t0));
1324 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1327 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1328 n_left_to_next, bi0, next0);
1331 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1334 errors = session_manager_flush_enqueue_events (my_thread_index);
1335 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1337 return from_frame->n_vectors;
1341 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1342 vlib_frame_t * from_frame)
1344 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1348 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1349 vlib_frame_t * from_frame)
1351 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1355 VLIB_REGISTER_NODE (tcp4_established_node) =
1357 .function = tcp4_established,
1358 .name = "tcp4-established",
1359 /* Takes a vector of packets. */
1360 .vector_size = sizeof (u32),
1361 .n_errors = TCP_N_ERROR,
1362 .error_strings = tcp_error_strings,
1363 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1366 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1367 foreach_tcp_state_next
1370 .format_trace = format_tcp_rx_trace_short,
1374 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1377 VLIB_REGISTER_NODE (tcp6_established_node) =
1379 .function = tcp6_established,
1380 .name = "tcp6-established",
1381 /* Takes a vector of packets. */
1382 .vector_size = sizeof (u32),
1383 .n_errors = TCP_N_ERROR,
1384 .error_strings = tcp_error_strings,
1385 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1388 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1389 foreach_tcp_state_next
1392 .format_trace = format_tcp_rx_trace_short,
1397 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1399 vlib_node_registration_t tcp4_syn_sent_node;
1400 vlib_node_registration_t tcp6_syn_sent_node;
1403 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1404 vlib_frame_t * from_frame, int is_ip4)
1406 tcp_main_t *tm = vnet_get_tcp_main ();
1407 u32 n_left_from, next_index, *from, *to_next;
1408 u32 my_thread_index = vm->thread_index, errors = 0;
1409 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
1411 from = vlib_frame_vector_args (from_frame);
1412 n_left_from = from_frame->n_vectors;
1414 next_index = node->cached_next_index;
1416 while (n_left_from > 0)
1420 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1422 while (n_left_from > 0 && n_left_to_next > 0)
1424 u32 bi0, ack0, seq0;
1427 tcp_header_t *tcp0 = 0;
1428 tcp_connection_t *tc0;
1429 tcp_connection_t *new_tc0;
1430 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1437 n_left_to_next -= 1;
1439 b0 = vlib_get_buffer (vm, bi0);
1441 tcp_half_open_connection_get (vnet_buffer (b0)->
1442 tcp.connection_index);
1444 ack0 = vnet_buffer (b0)->tcp.ack_number;
1445 seq0 = vnet_buffer (b0)->tcp.seq_number;
1446 tcp0 = tcp_buffer_hdr (b0);
1449 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1452 /* SYNs, FINs and data consume sequence numbers */
1453 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1454 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
1457 * 1. check the ACK bit
1461 * If the ACK bit is set
1462 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
1463 * the RST bit is set, if so drop the segment and return)
1464 * <SEQ=SEG.ACK><CTL=RST>
1465 * and discard the segment. Return.
1466 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
1470 if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt)
1472 if (!tcp_rst (tcp0))
1473 tcp_send_reset (b0, is_ip4);
1478 /* Make sure ACK is valid */
1479 if (tc0->snd_una > ack0)
1484 * 2. check the RST bit
1489 /* If ACK is acceptable, signal client that peer is not
1490 * willing to accept connection and drop connection*/
1493 stream_session_connect_notify (&tc0->connection, sst,
1495 tcp_connection_cleanup (tc0);
1501 * 3. check the security and precedence (skipped)
1505 * 4. check the SYN bit
1508 /* No SYN flag. Drop. */
1509 if (!tcp_syn (tcp0))
1512 /* Stop connection establishment and retransmit timers */
1513 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
1514 tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT_SYN);
1516 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
1517 * current thread pool. */
1518 pool_get (tm->connections[my_thread_index], new_tc0);
1519 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
1521 new_tc0->c_thread_index = my_thread_index;
1523 /* Cleanup half-open connection XXX lock */
1524 pool_put (tm->half_open_connections, tc0);
1526 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
1527 new_tc0->irs = seq0;
1530 tcp_options_parse (tcp0, &new_tc0->opt);
1532 if (tcp_opts_tstamp (&new_tc0->opt))
1534 new_tc0->tsval_recent = new_tc0->opt.tsval;
1535 new_tc0->tsval_recent_age = tcp_time_now ();
1538 if (tcp_opts_wscale (&new_tc0->opt))
1539 new_tc0->snd_wscale = new_tc0->opt.wscale;
1542 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
1543 new_tc0->snd_wl1 = seq0;
1544 new_tc0->snd_wl2 = ack0;
1546 tcp_connection_init_vars (new_tc0);
1548 /* SYN-ACK: See if we can switch to ESTABLISHED state */
1551 /* Our SYN is ACKed: we have iss < ack = snd_una */
1553 /* TODO Dequeue acknowledged segments if we support Fast Open */
1554 new_tc0->snd_una = ack0;
1555 new_tc0->state = TCP_STATE_ESTABLISHED;
1557 /* Make sure las is initialized for the wnd computation */
1558 new_tc0->rcv_las = new_tc0->rcv_nxt;
1560 /* Notify app that we have connection */
1561 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1563 stream_session_init_fifos_pointers (&new_tc0->connection,
1566 /* Make sure after data segment processing ACK is sent */
1567 new_tc0->flags |= TCP_CONN_SNDACK;
1569 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
1572 new_tc0->state = TCP_STATE_SYN_RCVD;
1574 /* Notify app that we have connection */
1575 stream_session_connect_notify (&new_tc0->connection, sst, 0);
1576 stream_session_init_fifos_pointers (&new_tc0->connection,
1579 tcp_make_synack (new_tc0, b0);
1580 next0 = tcp_next_output (is_ip4);
1585 /* Read data, if any */
1586 if (vnet_buffer (b0)->tcp.data_len)
1588 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1589 error0 = tcp_segment_rcv (tm, new_tc0, b0,
1590 vnet_buffer (b0)->tcp.data_len,
1592 if (error0 == TCP_ERROR_PURE_ACK)
1593 error0 = TCP_ERROR_SYN_ACKS_RCVD;
1597 tcp_make_ack (new_tc0, b0);
1598 next0 = tcp_next_output (new_tc0->c_is_ip4);
1603 b0->error = error0 ? node->errors[error0] : 0;
1604 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1606 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1607 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
1608 clib_memcpy (&t0->tcp_connection, tc0,
1609 sizeof (t0->tcp_connection));
1612 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1613 n_left_to_next, bi0, next0);
1616 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1619 errors = session_manager_flush_enqueue_events (my_thread_index);
1623 vlib_node_increment_counter (vm, tcp4_established_node.index,
1624 TCP_ERROR_EVENT_FIFO_FULL, errors);
1626 vlib_node_increment_counter (vm, tcp6_established_node.index,
1627 TCP_ERROR_EVENT_FIFO_FULL, errors);
1630 return from_frame->n_vectors;
1634 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
1635 vlib_frame_t * from_frame)
1637 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1641 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
1642 vlib_frame_t * from_frame)
1644 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1648 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
1650 .function = tcp4_syn_sent,
1651 .name = "tcp4-syn-sent",
1652 /* Takes a vector of packets. */
1653 .vector_size = sizeof (u32),
1654 .n_errors = TCP_N_ERROR,
1655 .error_strings = tcp_error_strings,
1656 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1659 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1660 foreach_tcp_state_next
1663 .format_trace = format_tcp_rx_trace_short,
1667 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
1670 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
1672 .function = tcp6_syn_sent_rcv,
1673 .name = "tcp6-syn-sent",
1674 /* Takes a vector of packets. */
1675 .vector_size = sizeof (u32),
1676 .n_errors = TCP_N_ERROR,
1677 .error_strings = tcp_error_strings,
1678 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
1681 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
1682 foreach_tcp_state_next
1685 .format_trace = format_tcp_rx_trace_short,
1689 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
1691 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
1692 * as per RFC793 p. 64
1695 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1696 vlib_frame_t * from_frame, int is_ip4)
1698 tcp_main_t *tm = vnet_get_tcp_main ();
1699 u32 n_left_from, next_index, *from, *to_next;
1700 u32 my_thread_index = vm->thread_index, errors = 0;
1702 from = vlib_frame_vector_args (from_frame);
1703 n_left_from = from_frame->n_vectors;
1705 next_index = node->cached_next_index;
1707 while (n_left_from > 0)
1711 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1713 while (n_left_from > 0 && n_left_to_next > 0)
1717 tcp_header_t *tcp0 = 0;
1718 tcp_connection_t *tc0;
1719 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1726 n_left_to_next -= 1;
1728 b0 = vlib_get_buffer (vm, bi0);
1729 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1731 if (PREDICT_FALSE (tc0 == 0))
1733 error0 = TCP_ERROR_INVALID_CONNECTION;
1737 tcp0 = tcp_buffer_hdr (b0);
1739 /* SYNs, FINs and data consume sequence numbers */
1740 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1741 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0)
1742 + vnet_buffer (b0)->tcp.data_len;
1745 * Special treatment for CLOSED
1749 case TCP_STATE_CLOSED:
1755 * For all other states (except LISTEN)
1758 /* 1-4: check SEQ, RST, SYN */
1760 (tcp_segment_validate (vm, tc0, b0, tcp0, &next0)))
1762 error0 = TCP_ERROR_SEGMENT_INVALID;
1766 /* 5: check the ACK field */
1769 case TCP_STATE_SYN_RCVD:
1771 * If the segment acknowledgment is not acceptable, form a
1773 * <SEQ=SEG.ACK><CTL=RST>
1776 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
1778 tcp_send_reset (b0, is_ip4);
1781 /* Switch state to ESTABLISHED */
1782 tc0->state = TCP_STATE_ESTABLISHED;
1784 /* Initialize session variables */
1785 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
1786 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
1788 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
1789 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
1791 /* Shoulder tap the server */
1792 stream_session_accept_notify (&tc0->connection);
1794 /* Reset SYN-ACK retransmit timer */
1795 tcp_retransmit_timer_reset (tc0);
1797 case TCP_STATE_ESTABLISHED:
1798 /* We can get packets in established state here because they
1799 * were enqueued before state change */
1800 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1804 case TCP_STATE_FIN_WAIT_1:
1805 /* In addition to the processing for the ESTABLISHED state, if
1806 * our FIN is now acknowledged then enter FIN-WAIT-2 and
1807 * continue processing in that state. */
1808 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1811 /* If FIN is ACKed */
1812 if (tc0->snd_una == tc0->snd_una_max)
1814 tc0->state = TCP_STATE_FIN_WAIT_2;
1815 /* Stop all timers, 2MSL will be set lower */
1816 tcp_connection_timers_reset (tc0);
1819 case TCP_STATE_FIN_WAIT_2:
1820 /* In addition to the processing for the ESTABLISHED state, if
1821 * the retransmission queue is empty, the user's CLOSE can be
1822 * acknowledged ("ok") but do not delete the TCB. */
1823 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1825 /* check if rtx queue is empty and ack CLOSE TODO */
1827 case TCP_STATE_CLOSE_WAIT:
1828 /* Do the same processing as for the ESTABLISHED state. */
1829 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1832 case TCP_STATE_CLOSING:
1833 /* In addition to the processing for the ESTABLISHED state, if
1834 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
1835 * otherwise ignore the segment. */
1836 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
1839 /* XXX test that send queue empty */
1840 tc0->state = TCP_STATE_TIME_WAIT;
1844 case TCP_STATE_LAST_ACK:
1845 /* The only thing that can arrive in this state is an
1846 * acknowledgment of our FIN. If our FIN is now acknowledged,
1847 * delete the TCB, enter the CLOSED state, and return. */
1849 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
1852 tc0->state = TCP_STATE_CLOSED;
1854 /* Don't delete the connection/session yet. Instead, wait a
1855 * reasonable amount of time until the pipes are cleared. In
1856 * particular, this makes sure that we won't have dead sessions
1857 * when processing events on the tx path */
1858 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
1860 /* Stop retransmit */
1861 tcp_retransmit_timer_reset (tc0);
1866 case TCP_STATE_TIME_WAIT:
1867 /* The only thing that can arrive in this state is a
1868 * retransmission of the remote FIN. Acknowledge it, and restart
1869 * the 2 MSL timeout. */
1878 /* 6: check the URG bit TODO */
1880 /* 7: process the segment text */
1883 case TCP_STATE_ESTABLISHED:
1884 case TCP_STATE_FIN_WAIT_1:
1885 case TCP_STATE_FIN_WAIT_2:
1886 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1887 error0 = tcp_segment_rcv (tm, tc0, b0,
1888 vnet_buffer (b0)->tcp.data_len,
1891 case TCP_STATE_CLOSE_WAIT:
1892 case TCP_STATE_CLOSING:
1893 case TCP_STATE_LAST_ACK:
1894 case TCP_STATE_TIME_WAIT:
1895 /* This should not occur, since a FIN has been received from the
1896 * remote side. Ignore the segment text. */
1900 /* 8: check the FIN bit */
1901 if (!tcp_fin (tcp0))
1906 case TCP_STATE_ESTABLISHED:
1907 case TCP_STATE_SYN_RCVD:
1908 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
1909 tcp_connection_timers_reset (tc0);
1910 tcp_make_fin (tc0, b0);
1911 next0 = tcp_next_output (tc0->c_is_ip4);
1912 stream_session_disconnect_notify (&tc0->connection);
1913 tc0->state = TCP_STATE_CLOSE_WAIT;
1915 case TCP_STATE_CLOSE_WAIT:
1916 case TCP_STATE_CLOSING:
1917 case TCP_STATE_LAST_ACK:
1920 case TCP_STATE_FIN_WAIT_1:
1921 tc0->state = TCP_STATE_TIME_WAIT;
1922 tcp_connection_timers_reset (tc0);
1923 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
1925 case TCP_STATE_FIN_WAIT_2:
1926 /* Got FIN, send ACK! */
1927 tc0->state = TCP_STATE_TIME_WAIT;
1928 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1929 tcp_make_ack (tc0, b0);
1930 next0 = tcp_next_output (is_ip4);
1932 case TCP_STATE_TIME_WAIT:
1933 /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
1936 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
1939 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1942 b0->error = error0 ? node->errors[error0] : 0;
1944 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1946 tcp_rx_trace_t *t0 =
1947 vlib_add_trace (vm, node, b0, sizeof (*t0));
1948 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
1951 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1952 n_left_to_next, bi0, next0);
1955 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1958 errors = session_manager_flush_enqueue_events (my_thread_index);
1962 vlib_node_increment_counter (vm, tcp4_established_node.index,
1963 TCP_ERROR_EVENT_FIFO_FULL, errors);
1965 vlib_node_increment_counter (vm, tcp6_established_node.index,
1966 TCP_ERROR_EVENT_FIFO_FULL, errors);
1969 return from_frame->n_vectors;
1973 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
1974 vlib_frame_t * from_frame)
1976 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1980 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
1981 vlib_frame_t * from_frame)
1983 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1987 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
1989 .function = tcp4_rcv_process,
1990 .name = "tcp4-rcv-process",
1991 /* Takes a vector of packets. */
1992 .vector_size = sizeof (u32),
1993 .n_errors = TCP_N_ERROR,
1994 .error_strings = tcp_error_strings,
1995 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
1998 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
1999 foreach_tcp_state_next
2002 .format_trace = format_tcp_rx_trace_short,
2006 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2009 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2011 .function = tcp6_rcv_process,
2012 .name = "tcp6-rcv-process",
2013 /* Takes a vector of packets. */
2014 .vector_size = sizeof (u32),
2015 .n_errors = TCP_N_ERROR,
2016 .error_strings = tcp_error_strings,
2017 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2020 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2021 foreach_tcp_state_next
2024 .format_trace = format_tcp_rx_trace_short,
2028 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2030 vlib_node_registration_t tcp4_listen_node;
2031 vlib_node_registration_t tcp6_listen_node;
2034 * LISTEN state processing as per RFC 793 p. 65
2037 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2038 vlib_frame_t * from_frame, int is_ip4)
2040 u32 n_left_from, next_index, *from, *to_next;
2041 u32 my_thread_index = vm->thread_index;
2042 tcp_main_t *tm = vnet_get_tcp_main ();
2043 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
2045 from = vlib_frame_vector_args (from_frame);
2046 n_left_from = from_frame->n_vectors;
2048 next_index = node->cached_next_index;
2050 while (n_left_from > 0)
2054 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2056 while (n_left_from > 0 && n_left_to_next > 0)
2061 tcp_header_t *th0 = 0;
2062 tcp_connection_t *lc0;
2065 tcp_connection_t *child0;
2066 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2073 n_left_to_next -= 1;
2075 b0 = vlib_get_buffer (vm, bi0);
2076 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2080 ip40 = vlib_buffer_get_current (b0);
2081 th0 = ip4_next_header (ip40);
2085 ip60 = vlib_buffer_get_current (b0);
2086 th0 = ip6_next_header (ip60);
2089 /* Create child session. For syn-flood protection use filter */
2091 /* 1. first check for an RST */
2095 /* 2. second check for an ACK */
2098 tcp_send_reset (b0, is_ip4);
2102 /* 3. check for a SYN (did that already) */
2104 /* Create child session and send SYN-ACK */
2105 pool_get (tm->connections[my_thread_index], child0);
2106 memset (child0, 0, sizeof (*child0));
2108 child0->c_c_index = child0 - tm->connections[my_thread_index];
2109 child0->c_lcl_port = lc0->c_lcl_port;
2110 child0->c_rmt_port = th0->src_port;
2111 child0->c_is_ip4 = is_ip4;
2112 child0->c_thread_index = my_thread_index;
2116 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2117 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2121 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2122 sizeof (ip6_address_t));
2123 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2124 sizeof (ip6_address_t));
2127 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2130 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2134 tcp_options_parse (th0, &child0->opt);
2136 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2137 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2138 child0->rcv_las = child0->rcv_nxt;
2139 child0->state = TCP_STATE_SYN_RCVD;
2141 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2142 * segments are used to initialize PAWS. */
2143 if (tcp_opts_tstamp (&child0->opt))
2145 child0->tsval_recent = child0->opt.tsval;
2146 child0->tsval_recent_age = tcp_time_now ();
2149 if (tcp_opts_wscale (&child0->opt))
2150 child0->snd_wscale = child0->opt.wscale;
2153 child0->snd_wnd = clib_net_to_host_u16 (th0->window);
2154 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2155 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2157 tcp_connection_init_vars (child0);
2159 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0);
2161 /* Reuse buffer to make syn-ack and send */
2162 tcp_make_synack (child0, b0);
2163 next0 = tcp_next_output (is_ip4);
2165 /* Init fifo pointers after we have iss */
2166 stream_session_init_fifos_pointers (&child0->connection,
2170 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2172 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2173 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2174 clib_memcpy (&t0->tcp_connection, lc0,
2175 sizeof (t0->tcp_connection));
2178 b0->error = node->errors[error0];
2180 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2181 n_left_to_next, bi0, next0);
2184 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2186 return from_frame->n_vectors;
2190 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2191 vlib_frame_t * from_frame)
2193 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2197 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2198 vlib_frame_t * from_frame)
2200 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2204 VLIB_REGISTER_NODE (tcp4_listen_node) =
2206 .function = tcp4_listen,
2207 .name = "tcp4-listen",
2208 /* Takes a vector of packets. */
2209 .vector_size = sizeof (u32),
2210 .n_errors = TCP_N_ERROR,
2211 .error_strings = tcp_error_strings,
2212 .n_next_nodes = TCP_LISTEN_N_NEXT,
2215 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2216 foreach_tcp_state_next
2219 .format_trace = format_tcp_rx_trace_short,
2223 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2226 VLIB_REGISTER_NODE (tcp6_listen_node) =
2228 .function = tcp6_listen,
2229 .name = "tcp6-listen",
2230 /* Takes a vector of packets. */
2231 .vector_size = sizeof (u32),
2232 .n_errors = TCP_N_ERROR,
2233 .error_strings = tcp_error_strings,
2234 .n_next_nodes = TCP_LISTEN_N_NEXT,
2237 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2238 foreach_tcp_state_next
2241 .format_trace = format_tcp_rx_trace_short,
2245 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2247 vlib_node_registration_t tcp4_input_node;
2248 vlib_node_registration_t tcp6_input_node;
2250 typedef enum _tcp_input_next
2252 TCP_INPUT_NEXT_DROP,
2253 TCP_INPUT_NEXT_LISTEN,
2254 TCP_INPUT_NEXT_RCV_PROCESS,
2255 TCP_INPUT_NEXT_SYN_SENT,
2256 TCP_INPUT_NEXT_ESTABLISHED,
2257 TCP_INPUT_NEXT_RESET,
2261 #define foreach_tcp4_input_next \
2262 _ (DROP, "error-drop") \
2263 _ (LISTEN, "tcp4-listen") \
2264 _ (RCV_PROCESS, "tcp4-rcv-process") \
2265 _ (SYN_SENT, "tcp4-syn-sent") \
2266 _ (ESTABLISHED, "tcp4-established") \
2267 _ (RESET, "tcp4-reset")
2269 #define foreach_tcp6_input_next \
2270 _ (DROP, "error-drop") \
2271 _ (LISTEN, "tcp6-listen") \
2272 _ (RCV_PROCESS, "tcp6-rcv-process") \
2273 _ (SYN_SENT, "tcp6-syn-sent") \
2274 _ (ESTABLISHED, "tcp6-established") \
2275 _ (RESET, "tcp6-reset")
2277 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2280 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2281 vlib_frame_t * from_frame, int is_ip4)
2283 u32 n_left_from, next_index, *from, *to_next;
2284 u32 my_thread_index = vm->thread_index;
2285 tcp_main_t *tm = vnet_get_tcp_main ();
2287 from = vlib_frame_vector_args (from_frame);
2288 n_left_from = from_frame->n_vectors;
2290 next_index = node->cached_next_index;
2292 while (n_left_from > 0)
2296 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2298 while (n_left_from > 0 && n_left_to_next > 0)
2300 int n_advance_bytes0, n_data_bytes0;
2303 tcp_header_t *tcp0 = 0;
2304 tcp_connection_t *tc0;
2307 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2315 n_left_to_next -= 1;
2317 b0 = vlib_get_buffer (vm, bi0);
2318 vnet_buffer (b0)->tcp.flags = 0;
2320 /* Checksum computed by ipx_local no need to compute again */
2324 ip40 = vlib_buffer_get_current (b0);
2325 tcp0 = ip4_next_header (ip40);
2326 n_advance_bytes0 = (ip4_header_bytes (ip40)
2327 + tcp_header_bytes (tcp0));
2328 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2331 /* lookup session */
2333 (tcp_connection_t *)
2334 stream_session_lookup_transport4 (&ip40->dst_address,
2338 SESSION_TYPE_IP4_TCP,
2343 ip60 = vlib_buffer_get_current (b0);
2344 tcp0 = ip6_next_header (ip60);
2345 n_advance_bytes0 = tcp_header_bytes (tcp0);
2346 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2348 n_advance_bytes0 += sizeof (ip60[0]);
2351 (tcp_connection_t *)
2352 stream_session_lookup_transport6 (&ip60->src_address,
2356 SESSION_TYPE_IP6_TCP,
2361 if (PREDICT_FALSE (n_advance_bytes0 < 0))
2363 error0 = TCP_ERROR_LENGTH;
2367 /* Session exists */
2368 if (PREDICT_TRUE (0 != tc0))
2370 /* Save connection index */
2371 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2372 vnet_buffer (b0)->tcp.seq_number =
2373 clib_net_to_host_u32 (tcp0->seq_number);
2374 vnet_buffer (b0)->tcp.ack_number =
2375 clib_net_to_host_u32 (tcp0->ack_number);
2377 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
2378 - (u8 *) vlib_buffer_get_current (b0);
2379 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
2380 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
2382 flags0 = tcp0->flags & filter_flags;
2383 next0 = tm->dispatch_table[tc0->state][flags0].next;
2384 error0 = tm->dispatch_table[tc0->state][flags0].error;
2386 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH))
2388 tcp_state_t state0 = tc0->state;
2389 /* Overload tcp flags to store state */
2390 vnet_buffer (b0)->tcp.flags = tc0->state;
2391 clib_warning ("disp error state %U flags %U",
2392 format_tcp_state, &state0,
2393 format_tcp_flags, (int) flags0);
2399 next0 = TCP_INPUT_NEXT_RESET;
2400 error0 = TCP_ERROR_NO_LISTENER;
2404 b0->error = error0 ? node->errors[error0] : 0;
2406 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2408 tcp_rx_trace_t *t0 =
2409 vlib_add_trace (vm, node, b0, sizeof (*t0));
2410 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2413 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2414 n_left_to_next, bi0, next0);
2417 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2420 return from_frame->n_vectors;
2424 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2425 vlib_frame_t * from_frame)
2427 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2431 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2432 vlib_frame_t * from_frame)
2434 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2438 VLIB_REGISTER_NODE (tcp4_input_node) =
2440 .function = tcp4_input,
2441 .name = "tcp4-input",
2442 /* Takes a vector of packets. */
2443 .vector_size = sizeof (u32),
2444 .n_errors = TCP_N_ERROR,
2445 .error_strings = tcp_error_strings,
2446 .n_next_nodes = TCP_INPUT_N_NEXT,
2449 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2450 foreach_tcp4_input_next
2453 .format_buffer = format_tcp_header,
2454 .format_trace = format_tcp_rx_trace,
2458 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
2461 VLIB_REGISTER_NODE (tcp6_input_node) =
2463 .function = tcp6_input,
2464 .name = "tcp6-input",
2465 /* Takes a vector of packets. */
2466 .vector_size = sizeof (u32),
2467 .n_errors = TCP_N_ERROR,
2468 .error_strings = tcp_error_strings,
2469 .n_next_nodes = TCP_INPUT_N_NEXT,
2472 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2473 foreach_tcp6_input_next
2476 .format_buffer = format_tcp_header,
2477 .format_trace = format_tcp_rx_trace,
2481 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
2484 tcp_dispatch_table_init (tcp_main_t * tm)
2487 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
2488 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
2490 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
2491 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
2494 #define _(t,f,n,e) \
2496 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
2497 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
2500 /* SYNs for new connections -> tcp-listen. */
2501 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
2502 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
2503 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2504 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2505 /* SYN-ACK for a SYN */
2506 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2508 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2509 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2510 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2512 /* ACK for for established connection -> tcp-established. */
2513 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2514 /* FIN for for established connection -> tcp-established. */
2515 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2516 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2518 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2519 /* ACK or FIN-ACK to our FIN */
2520 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2521 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
2523 /* FIN in reply to our FIN from the other side */
2524 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2525 /* FIN confirming that the peer (app) has closed */
2526 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2527 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2529 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2530 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
2535 tcp_input_init (vlib_main_t * vm)
2537 clib_error_t *error = 0;
2538 tcp_main_t *tm = vnet_get_tcp_main ();
2540 if ((error = vlib_call_init_function (vm, tcp_init)))
2543 /* Initialize dispatch table. */
2544 tcp_dispatch_table_init (tm);
2549 VLIB_INIT_FUNCTION (tcp_input_init);
2552 * fd.io coding-style-patch-verification: ON
2555 * eval: (c-set-style "gnu")