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 _ (DROP4, "ip4-drop") \
31 _ (DROP6, "ip6-drop") \
32 _ (TCP4_OUTPUT, "tcp4-output") \
33 _ (TCP6_OUTPUT, "tcp6-output")
35 typedef enum _tcp_established_next
37 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
38 foreach_tcp_state_next
40 TCP_ESTABLISHED_N_NEXT,
41 } tcp_established_next_t;
43 typedef enum _tcp_rcv_process_next
45 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
46 foreach_tcp_state_next
48 TCP_RCV_PROCESS_N_NEXT,
49 } tcp_rcv_process_next_t;
51 typedef enum _tcp_syn_sent_next
53 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
54 foreach_tcp_state_next
57 } tcp_syn_sent_next_t;
59 typedef enum _tcp_listen_next
61 #define _(s,n) TCP_LISTEN_NEXT_##s,
62 foreach_tcp_state_next
67 /* Generic, state independent indices */
68 typedef enum _tcp_state_next
70 #define _(s,n) TCP_NEXT_##s,
71 foreach_tcp_state_next
76 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
77 : TCP_NEXT_TCP6_OUTPUT)
79 #define tcp_next_drop(is_ip4) (is_ip4 ? TCP_NEXT_DROP4 \
82 vlib_node_registration_t tcp4_established_node;
83 vlib_node_registration_t tcp6_established_node;
86 * Validate segment sequence number. As per RFC793:
88 * Segment Receive Test
90 * ------- ------- -------------------------------------------
91 * 0 0 SEG.SEQ = RCV.NXT
92 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
94 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
95 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
97 * This ultimately consists in checking if segment falls within the window.
98 * The one important difference compared to RFC793 is that we use rcv_las,
99 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
100 * peer's reference when computing our receive window.
103 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
104 * however, is too strict when we have retransmits. Instead we just check that
105 * the seq is not beyond the right edge and that the end of the segment is not
106 * less than the left edge.
108 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
109 * use rcv_nxt in the right edge window test instead of rcv_las.
113 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
115 return (seq_geq (end_seq, tc->rcv_las)
116 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
120 * Parse TCP header options.
122 * @param th TCP header
123 * @param to TCP options data structure to be populated
124 * @return -1 if parsing failed
127 tcp_options_parse (tcp_header_t * th, tcp_options_t * to)
130 u8 opt_len, opts_len, kind;
134 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
135 data = (const u8 *) (th + 1);
137 /* Zero out all flags but those set in SYN */
138 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE);
140 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
144 /* Get options length */
145 if (kind == TCP_OPTION_EOL)
147 else if (kind == TCP_OPTION_NOOP)
159 /* weird option length */
160 if (opt_len < 2 || opt_len > opts_len)
168 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
170 to->flags |= TCP_OPTS_FLAG_MSS;
171 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
174 case TCP_OPTION_WINDOW_SCALE:
175 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
177 to->flags |= TCP_OPTS_FLAG_WSCALE;
178 to->wscale = data[2];
179 if (to->wscale > TCP_MAX_WND_SCALE)
181 clib_warning ("Illegal window scaling value: %d",
183 to->wscale = TCP_MAX_WND_SCALE;
187 case TCP_OPTION_TIMESTAMP:
188 if (opt_len == TCP_OPTION_LEN_TIMESTAMP)
190 to->flags |= TCP_OPTS_FLAG_TSTAMP;
191 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
192 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
195 case TCP_OPTION_SACK_PERMITTED:
196 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
197 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
199 case TCP_OPTION_SACK_BLOCK:
200 /* If SACK permitted was not advertised or a SYN, break */
201 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
204 /* If too short or not correctly formatted, break */
205 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
208 to->flags |= TCP_OPTS_FLAG_SACK;
209 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
210 vec_reset_length (to->sacks);
211 for (j = 0; j < to->n_sack_blocks; j++)
213 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
214 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
215 vec_add1 (to->sacks, b);
219 /* Nothing to see here */
227 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
228 * timestamp to echo and it's less than tsval_recent, drop segment
229 * but still send an ACK in order to retain TCP's mechanism for detecting
230 * and recovering from half-open connections
232 * Or at least that's what the theory says. It seems that this might not work
233 * very well with packet reordering and fast retransmit. XXX
236 tcp_segment_check_paws (tcp_connection_t * tc)
238 return tcp_opts_tstamp (&tc->rcv_opts) && tc->tsval_recent
239 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
243 * Update tsval recent
246 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
249 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
250 * of an incoming segment:
251 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
252 * then the TSval from the segment is copied to TS.Recent;
253 * otherwise, the TSval is ignored.
255 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
256 && seq_leq (tc->rcv_las, seq_end))
258 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
259 tc->tsval_recent = tc->rcv_opts.tsval;
260 tc->tsval_recent_age = tcp_time_now ();
265 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
267 * It first verifies if segment has a wrapped sequence number (PAWS) and then
268 * does the processing associated to the first four steps (ignoring security
269 * and precedence): sequence number, rst bit and syn bit checks.
271 * @return 0 if segments passes validation.
274 tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0,
275 vlib_buffer_t * b0, tcp_header_t * th0, u32 * next0)
277 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
280 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts)))
282 clib_warning ("options parse error");
286 if (tcp_segment_check_paws (tc0))
290 clib_warning ("paws failed\n%U", format_tcp_connection, tc0, 2);
291 clib_warning ("seq %u seq_end %u ack %u",
292 vnet_buffer (b0)->tcp.seq_number - tc0->irs,
293 vnet_buffer (b0)->tcp.seq_end - tc0->irs,
294 vnet_buffer (b0)->tcp.ack_number - tc0->iss);
296 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
297 vnet_buffer (b0)->tcp.seq_end);
299 /* If it just so happens that a segment updates tsval_recent for a
300 * segment over 24 days old, invalidate tsval_recent. */
301 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
304 /* Age isn't reset until we get a valid tsval (bsd inspired) */
305 tc0->tsval_recent = 0;
306 clib_warning ("paws failed - really old segment. REALLY?");
310 /* Drop after ack if not rst */
313 tcp_make_ack (tc0, b0);
314 *next0 = tcp_next_output (tc0->c_is_ip4);
315 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
321 /* 1st: check sequence number */
322 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
323 vnet_buffer (b0)->tcp.seq_end))
325 /* If our window is 0 and the packet is in sequence, let it pass
326 * through for ack processing. It should be dropped later.*/
327 if (tc0->rcv_wnd == 0
328 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
330 /* TODO Should segment be tagged? */
334 /* If not RST, send dup ack */
337 tcp_make_ack (tc0, b0);
338 *next0 = tcp_next_output (tc0->c_is_ip4);
339 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
345 /* 2nd: check the RST bit */
348 tcp_connection_reset (tc0);
352 /* 3rd: check security and precedence (skip) */
354 /* 4th: check the SYN bit */
357 /* TODO implement RFC 5961 */
358 if (tc0->state == TCP_STATE_SYN_RCVD)
360 tcp_make_synack (tc0, b0);
361 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
365 tcp_make_ack (tc0, b0);
366 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
368 *next0 = tcp_next_output (tc0->c_is_ip4);
372 /* If segment in window, save timestamp */
373 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
374 vnet_buffer (b0)->tcp.seq_end);
379 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
381 /* SND.UNA =< SEG.ACK =< SND.NXT */
382 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
383 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
387 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
389 * Note that although the original article, srtt and rttvar are scaled
390 * to minimize round-off errors, here we don't. Instead, we rely on
391 * better precision time measurements.
393 * TODO support us rtt resolution
396 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
402 err = mrtt - tc->srtt;
404 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
405 * The increase should be bound */
406 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
407 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
408 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
412 /* First measurement. */
414 tc->rttvar = mrtt >> 1;
419 tcp_update_rto (tcp_connection_t * tc)
421 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
422 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
426 * Update RTT estimate and RTO timer
428 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
429 * timing. Middle boxes are known to fiddle with TCP options so we
430 * should give higher priority to ACK timing.
432 * This should be called only if previously sent bytes have been acked.
434 * return 1 if valid rtt 0 otherwise
437 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
441 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
442 * RTT because they're ambiguous. */
443 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
446 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
448 mrtt = tcp_time_now () - tc->rtt_ts;
450 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
451 * snd_una, i.e., the left side of the send window:
452 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
453 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
455 mrtt = tcp_time_now () - tc->rcv_opts.tsecr;
458 /* Ignore dubious measurements */
459 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
462 tcp_estimate_rtt (tc, mrtt);
466 /* Allow measuring of a new RTT */
469 /* If we got here something must've been ACKed so make sure boff is 0,
470 * even if mrrt is not valid since we update the rto lower */
478 * Dequeue bytes that have been acked and while at it update RTT estimates.
481 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
483 /* Dequeue the newly ACKed add SACKed bytes */
484 stream_session_dequeue_drop (&tc->connection,
485 tc->bytes_acked + tc->sack_sb.snd_una_adv);
487 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
489 /* Update rtt and rto */
490 tcp_update_rtt (tc, ack);
492 /* If everything has been acked, stop retransmit timer
493 * otherwise update. */
494 tcp_retransmit_timer_update (tc);
498 * Check if duplicate ack as per RFC5681 Sec. 2
501 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
504 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
505 && seq_gt (tc->snd_una_max, tc->snd_una)
506 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
507 && (prev_snd_wnd == tc->snd_wnd));
511 * Checks if ack is a congestion control event.
514 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
515 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
517 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
518 * defined to be 'duplicate' */
519 *is_dack = tc->sack_sb.last_sacked_bytes
520 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
522 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
526 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
528 sack_scoreboard_hole_t *next, *prev;
530 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
532 next = pool_elt_at_index (sb->holes, hole->next);
533 next->prev = hole->prev;
537 sb->tail = hole->prev;
540 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
542 prev = pool_elt_at_index (sb->holes, hole->prev);
543 prev->next = hole->next;
547 sb->head = hole->next;
550 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
551 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
553 /* Poison the entry */
555 memset (hole, 0xfe, sizeof (*hole));
557 pool_put (sb->holes, hole);
560 sack_scoreboard_hole_t *
561 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
564 sack_scoreboard_hole_t *hole, *next, *prev;
567 pool_get (sb->holes, hole);
568 memset (hole, 0, sizeof (*hole));
572 hole_index = scoreboard_hole_index (sb, hole);
574 prev = scoreboard_get_hole (sb, prev_index);
577 hole->prev = prev_index;
578 hole->next = prev->next;
580 if ((next = scoreboard_next_hole (sb, hole)))
581 next->prev = hole_index;
583 sb->tail = hole_index;
585 prev->next = hole_index;
589 sb->head = hole_index;
590 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
591 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
598 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
600 sack_scoreboard_hole_t *hole, *prev;
601 u32 bytes = 0, blks = 0;
604 sb->sacked_bytes = 0;
605 hole = scoreboard_last_hole (sb);
609 if (seq_gt (sb->high_sacked, hole->end))
611 bytes = sb->high_sacked - hole->end;
615 while ((prev = scoreboard_prev_hole (sb, hole))
616 && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
617 && blks < TCP_DUPACK_THRESHOLD))
619 bytes += hole->start - prev->end;
626 sb->lost_bytes += scoreboard_hole_bytes (hole);
629 hole = scoreboard_prev_hole (sb, hole);
631 bytes += prev->start - hole->end;
633 sb->sacked_bytes = bytes;
637 * Figure out the next hole to retransmit
639 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
641 sack_scoreboard_hole_t *
642 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
643 sack_scoreboard_hole_t * start,
645 u8 * can_rescue, u8 * snd_limited)
647 sack_scoreboard_hole_t *hole = 0;
649 hole = start ? start : scoreboard_first_hole (sb);
650 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
651 hole = scoreboard_next_hole (sb, hole);
653 /* Nothing, return */
656 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
660 /* Rule (1): if higher than rxt, less than high_sacked and lost */
661 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
663 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
667 /* Rule (2): output takes care of transmitting new data */
668 if (!have_sent_1_smss)
671 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
673 /* Rule (3): if hole not lost */
674 else if (seq_lt (hole->start, sb->high_sacked))
677 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
679 /* Rule (4): if hole beyond high_sacked */
682 ASSERT (seq_geq (hole->start, sb->high_sacked));
685 /* HighRxt MUST NOT be updated */
690 if (hole && seq_lt (sb->high_rxt, hole->start))
691 sb->high_rxt = hole->start;
697 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
699 sack_scoreboard_hole_t *hole;
700 hole = scoreboard_first_hole (sb);
703 seq = seq_gt (seq, hole->start) ? seq : hole->start;
704 sb->cur_rxt_hole = sb->head;
710 * Test that scoreboard is sane after recovery
712 * Returns 1 if scoreboard is empty or if first hole beyond
716 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
718 sack_scoreboard_hole_t *hole;
719 hole = scoreboard_first_hole (&tc->sack_sb);
720 return (!hole || seq_geq (hole->start, tc->snd_una));
724 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
726 sack_scoreboard_t *sb = &tc->sack_sb;
727 sack_block_t *blk, tmp;
728 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
729 u32 blk_index = 0, old_sacked_bytes, hole_index;
732 sb->last_sacked_bytes = 0;
734 old_sacked_bytes = sb->sacked_bytes;
735 sb->last_bytes_delivered = 0;
737 if (!tcp_opts_sack (&tc->rcv_opts)
738 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
741 /* Remove invalid blocks */
742 blk = tc->rcv_opts.sacks;
743 while (blk < vec_end (tc->rcv_opts.sacks))
745 if (seq_lt (blk->start, blk->end)
746 && seq_gt (blk->start, tc->snd_una)
747 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
752 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
755 /* Add block for cumulative ack */
756 if (seq_gt (ack, tc->snd_una))
758 tmp.start = tc->snd_una;
760 vec_add1 (tc->rcv_opts.sacks, tmp);
763 if (vec_len (tc->rcv_opts.sacks) == 0)
766 tcp_scoreboard_trace_add (tc, ack);
768 /* Make sure blocks are ordered */
769 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
770 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
771 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
773 tmp = tc->rcv_opts.sacks[i];
774 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
775 tc->rcv_opts.sacks[j] = tmp;
778 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
780 /* If no holes, insert the first that covers all outstanding bytes */
781 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
782 tc->snd_una, tc->snd_una_max);
783 sb->tail = scoreboard_hole_index (sb, last_hole);
784 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
785 sb->high_sacked = tmp.end;
789 /* If we have holes but snd_una_max is beyond the last hole, update
791 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
792 last_hole = scoreboard_last_hole (sb);
793 if (seq_gt (tc->snd_una_max, last_hole->end))
795 if (seq_geq (last_hole->start, sb->high_sacked))
797 last_hole->end = tc->snd_una_max;
799 /* New hole after high sacked block */
800 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
802 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
806 /* Keep track of max byte sacked for when the last hole
808 if (seq_gt (tmp.end, sb->high_sacked))
809 sb->high_sacked = tmp.end;
812 /* Walk the holes with the SACK blocks */
813 hole = pool_elt_at_index (sb->holes, sb->head);
814 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
816 blk = &tc->rcv_opts.sacks[blk_index];
817 if (seq_leq (blk->start, hole->start))
819 /* Block covers hole. Remove hole */
820 if (seq_geq (blk->end, hole->end))
822 next_hole = scoreboard_next_hole (sb, hole);
824 /* Byte accounting: snd_una needs to be advanced */
829 if (seq_lt (ack, next_hole->start))
830 sb->snd_una_adv = next_hole->start - ack;
831 sb->last_bytes_delivered +=
832 next_hole->start - hole->end;
836 ASSERT (seq_geq (sb->high_sacked, ack));
837 sb->snd_una_adv = sb->high_sacked - ack;
838 sb->last_bytes_delivered += sb->high_sacked - hole->end;
842 scoreboard_remove_hole (sb, hole);
845 /* Partial 'head' overlap */
848 if (seq_gt (blk->end, hole->start))
850 hole->start = blk->end;
857 /* Hole must be split */
858 if (seq_lt (blk->end, hole->end))
860 hole_index = scoreboard_hole_index (sb, hole);
861 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
864 /* Pool might've moved */
865 hole = scoreboard_get_hole (sb, hole_index);
866 hole->end = blk->start;
868 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
870 else if (seq_lt (blk->start, hole->end))
872 hole->end = blk->start;
874 hole = scoreboard_next_hole (sb, hole);
878 scoreboard_update_bytes (tc, sb);
879 sb->last_sacked_bytes = sb->sacked_bytes
880 - (old_sacked_bytes - sb->last_bytes_delivered);
881 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes);
882 ASSERT (sb->sacked_bytes == 0
883 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
884 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
885 - seq_max (tc->snd_una, ack));
886 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
887 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
891 * Try to update snd_wnd based on feedback received from peer.
893 * If successful, and new window is 'effectively' 0, activate persist
897 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
899 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
900 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
901 if (seq_lt (tc->snd_wl1, seq)
902 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
904 tc->snd_wnd = snd_wnd;
907 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
909 if (tc->snd_wnd < tc->snd_mss)
911 /* Set persist timer if not set and we just got 0 wnd */
912 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
913 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
914 tcp_persist_timer_set (tc);
918 tcp_persist_timer_reset (tc);
919 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
929 tcp_cc_init_congestion (tcp_connection_t * tc)
931 tcp_fastrecovery_on (tc);
932 tc->snd_congestion = tc->snd_una_max;
933 tc->cc_algo->congestion (tc);
934 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
938 tcp_cc_recovery_exit (tcp_connection_t * tc)
944 tc->snd_nxt = tc->snd_una_max;
945 tcp_recovery_off (tc);
946 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
950 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
952 tc->cc_algo->recovered (tc);
953 tc->snd_rxt_bytes = 0;
955 tc->snd_nxt = tc->snd_una_max;
956 tcp_fastrecovery_off (tc);
957 tcp_fastrecovery_1_smss_off (tc);
958 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
962 tcp_cc_congestion_undo (tcp_connection_t * tc)
964 tc->cwnd = tc->prev_cwnd;
965 tc->ssthresh = tc->prev_ssthresh;
966 tc->snd_nxt = tc->snd_una_max;
968 if (tcp_in_recovery (tc))
969 tcp_cc_recovery_exit (tc);
970 ASSERT (tc->rto_boff == 0);
971 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
972 /* TODO extend for fastrecovery */
976 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
978 return (tcp_in_recovery (tc) && tc->rto_boff == 1
980 && tcp_opts_tstamp (&tc->rcv_opts)
981 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
985 tcp_cc_recover (tcp_connection_t * tc)
987 ASSERT (tcp_in_cong_recovery (tc));
988 if (tcp_cc_is_spurious_retransmit (tc))
990 tcp_cc_congestion_undo (tc);
994 if (tcp_in_recovery (tc))
995 tcp_cc_recovery_exit (tc);
996 else if (tcp_in_fastrecovery (tc))
997 tcp_cc_fastrecovery_exit (tc);
999 ASSERT (tc->rto_boff == 0);
1000 ASSERT (!tcp_in_cong_recovery (tc));
1001 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1006 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1008 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1010 /* Congestion avoidance */
1011 tc->cc_algo->rcv_ack (tc);
1012 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1014 /* If a cumulative ack, make sure dupacks is 0 */
1015 tc->rcv_dupacks = 0;
1017 /* When dupacks hits the threshold we only enter fast retransmit if
1018 * cumulative ack covers more than snd_congestion. Should snd_una
1019 * wrap this test may fail under otherwise valid circumstances.
1020 * Therefore, proactively update snd_congestion when wrap detected. */
1022 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1023 && seq_gt (tc->snd_congestion, tc->snd_una)))
1024 tc->snd_congestion = tc->snd_una - 1;
1028 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1030 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1034 tcp_should_fastrecover (tcp_connection_t * tc)
1036 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1037 || tcp_should_fastrecover_sack (tc));
1041 * One function to rule them all ... and in the darkness bind them
1044 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1049 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1050 * it account for the bytes that left the network.
1054 ASSERT (tc->snd_una != tc->snd_una_max
1055 || tc->sack_sb.last_sacked_bytes);
1059 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1061 ASSERT (tcp_in_fastrecovery (tc));
1062 /* Pure duplicate ack. If some data got acked, it's handled lower */
1063 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1066 else if (tcp_should_fastrecover (tc))
1068 /* Things are already bad */
1069 if (tcp_in_cong_recovery (tc))
1071 tc->rcv_dupacks = 0;
1072 goto partial_ack_test;
1075 /* If of of the two conditions lower hold, reset dupacks because
1076 * we're probably after timeout (RFC6582 heuristics).
1077 * If Cumulative ack does not cover more than congestion threshold,
1079 * 1) The following doesn't hold: The congestion window is greater
1080 * than SMSS bytes and the difference between highest_ack
1081 * and prev_highest_ack is at most 4*SMSS bytes
1082 * 2) Echoed timestamp in the last non-dup ack does not equal the
1085 if (seq_leq (tc->snd_una, tc->snd_congestion)
1086 && ((!(tc->cwnd > tc->snd_mss
1087 && tc->bytes_acked <= 4 * tc->snd_mss))
1088 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1090 tc->rcv_dupacks = 0;
1094 tcp_cc_init_congestion (tc);
1095 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1097 /* The first segment MUST be retransmitted */
1098 tcp_retransmit_first_unacked (tc);
1100 /* Post retransmit update cwnd to ssthresh and account for the
1101 * three segments that have left the network and should've been
1102 * buffered at the receiver XXX */
1103 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1104 ASSERT (tc->cwnd >= tc->snd_mss);
1106 /* If cwnd allows, send more data */
1107 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1109 scoreboard_init_high_rxt (&tc->sack_sb,
1110 tc->snd_una + tc->snd_mss);
1111 tcp_fast_retransmit_sack (tc);
1115 tcp_fast_retransmit_no_sack (tc);
1120 else if (!tc->bytes_acked
1121 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1123 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1132 if (!tc->bytes_acked)
1137 * Legitimate ACK. 1) See if we can exit recovery
1139 /* XXX limit this only to first partial ack? */
1140 tcp_retransmit_timer_update (tc);
1142 if (seq_geq (tc->snd_una, tc->snd_congestion))
1144 /* If spurious return, we've already updated everything */
1145 if (tcp_cc_recover (tc))
1147 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1151 tc->snd_nxt = tc->snd_una_max;
1153 /* Treat as congestion avoidance ack */
1154 tc->cc_algo->rcv_ack (tc);
1155 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1160 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1162 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1164 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1165 * reset dupacks to 0 */
1166 tc->rcv_dupacks = 0;
1168 tcp_retransmit_first_unacked (tc);
1170 /* Post RTO timeout don't try anything fancy */
1171 if (tcp_in_recovery (tc))
1174 /* Remove retransmitted bytes that have been delivered */
1175 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1176 >= tc->sack_sb.last_bytes_delivered
1177 || (tc->flags & TCP_CONN_FINSNT));
1179 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1181 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1182 * remove sacked bytes delivered */
1183 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1184 - tc->sack_sb.last_bytes_delivered;
1185 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1186 tc->snd_rxt_bytes -= rxt_delivered;
1190 /* Either all retransmitted holes have been acked, or we're
1191 * "in the blind" and retransmitting segment by segment */
1192 tc->snd_rxt_bytes = 0;
1195 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1198 * Since this was a partial ack, try to retransmit some more data
1200 tcp_fast_retransmit (tc);
1204 tcp_cc_init (tcp_connection_t * tc)
1206 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
1207 tc->cc_algo->init (tc);
1211 * Process incoming ACK
1214 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1215 tcp_header_t * th, u32 * next, u32 * error)
1217 u32 prev_snd_wnd, prev_snd_una;
1220 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1222 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1223 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1225 /* If we have outstanding data and this is within the window, accept it,
1226 * probably retransmit has timed out. Otherwise ACK segment and then
1228 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1230 tcp_make_ack (tc, b);
1231 *next = tcp_next_output (tc->c_is_ip4);
1232 *error = TCP_ERROR_ACK_INVALID;
1233 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1234 vnet_buffer (b)->tcp.ack_number);
1238 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1239 vnet_buffer (b)->tcp.ack_number);
1241 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1242 *error = TCP_ERROR_ACK_FUTURE;
1245 /* If old ACK, probably it's an old dupack */
1246 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1248 *error = TCP_ERROR_ACK_OLD;
1249 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1250 vnet_buffer (b)->tcp.ack_number);
1251 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1253 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
1254 tcp_cc_handle_event (tc, 1);
1256 /* Don't drop yet */
1261 * Looks okay, process feedback
1264 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1265 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1267 prev_snd_wnd = tc->snd_wnd;
1268 prev_snd_una = tc->snd_una;
1269 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1270 vnet_buffer (b)->tcp.ack_number,
1271 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1272 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1273 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1274 tcp_validate_txf_size (tc, tc->bytes_acked);
1276 if (tc->bytes_acked)
1277 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1279 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1282 * Check if we have congestion event
1285 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1287 tcp_cc_handle_event (tc, is_dack);
1288 if (!tcp_in_cong_recovery (tc))
1290 *error = TCP_ERROR_ACK_DUP;
1291 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1292 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1296 * Update congestion control (slow start/congestion avoidance)
1298 tcp_cc_update (tc, b);
1304 tcp_sack_vector_is_sane (sack_block_t * sacks)
1307 for (i = 1; i < vec_len (sacks); i++)
1309 if (sacks[i - 1].end == sacks[i].start)
1316 * Build SACK list as per RFC2018.
1318 * Makes sure the first block contains the segment that generated the current
1319 * ACK and the following ones are the ones most recently reported in SACK
1322 * @param tc TCP connection for which the SACK list is updated
1323 * @param start Start sequence number of the newest SACK block
1324 * @param end End sequence of the newest SACK block
1327 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1329 sack_block_t *new_list = 0, *block = 0;
1332 /* If the first segment is ooo add it to the list. Last write might've moved
1333 * rcv_nxt over the first segment. */
1334 if (seq_lt (tc->rcv_nxt, start))
1336 vec_add2 (new_list, block, 1);
1337 block->start = start;
1341 /* Find the blocks still worth keeping. */
1342 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1344 /* Discard if rcv_nxt advanced beyond current block */
1345 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1348 /* Merge or drop if segment overlapped by the new segment */
1349 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1350 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1352 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1353 new_list[0].start = tc->snd_sacks[i].start;
1354 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1355 new_list[0].end = tc->snd_sacks[i].end;
1359 /* Save to new SACK list if we have space. */
1360 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1362 vec_add1 (new_list, tc->snd_sacks[i]);
1366 clib_warning ("sack discarded");
1370 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1372 /* Replace old vector with new one */
1373 vec_free (tc->snd_sacks);
1374 tc->snd_sacks = new_list;
1376 /* Segments should not 'touch' */
1377 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1380 /** Enqueue data for delivery to application */
1382 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1385 int written, error = TCP_ERROR_ENQUEUED;
1387 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1389 /* Pure ACK. Update rcv_nxt and be done. */
1390 if (PREDICT_FALSE (data_len == 0))
1392 return TCP_ERROR_PURE_ACK;
1395 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1396 1 /* queue event */ , 1);
1398 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1400 /* Update rcv_nxt */
1401 if (PREDICT_TRUE (written == data_len))
1403 tc->rcv_nxt += written;
1405 /* If more data written than expected, account for out-of-order bytes. */
1406 else if (written > data_len)
1408 tc->rcv_nxt += written;
1410 /* Send ACK confirming the update */
1411 tc->flags |= TCP_CONN_SNDACK;
1413 else if (written > 0)
1415 /* We've written something but FIFO is probably full now */
1416 tc->rcv_nxt += written;
1418 /* Depending on how fast the app is, all remaining buffers in burst will
1419 * not be enqueued. Inform peer */
1420 tc->flags |= TCP_CONN_SNDACK;
1422 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1426 tc->flags |= TCP_CONN_SNDACK;
1427 return TCP_ERROR_FIFO_FULL;
1430 /* Update SACK list if need be */
1431 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1433 /* Remove SACK blocks that have been delivered */
1434 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1440 /** Enqueue out-of-order data */
1442 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1445 stream_session_t *s0;
1448 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1450 /* Pure ACK. Do nothing */
1451 if (PREDICT_FALSE (data_len == 0))
1453 return TCP_ERROR_PURE_ACK;
1456 /* Enqueue out-of-order data with relative offset */
1457 rv = session_enqueue_stream_connection (&tc->connection, b,
1458 vnet_buffer (b)->tcp.seq_number -
1459 tc->rcv_nxt, 0 /* queue event */ ,
1462 /* Nothing written */
1465 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1466 return TCP_ERROR_FIFO_FULL;
1469 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1471 /* Update SACK list if in use */
1472 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1474 ooo_segment_t *newest;
1477 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1479 /* Get the newest segment from the fifo */
1480 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1483 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1484 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1485 start = tc->rcv_nxt + offset;
1486 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1487 tcp_update_sack_list (tc, start, end);
1488 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1492 return TCP_ERROR_ENQUEUED;
1496 * Check if ACK could be delayed. If ack can be delayed, it should return
1497 * true for a full frame. If we're always acking return 0.
1500 tcp_can_delack (tcp_connection_t * tc)
1502 /* Send ack if ... */
1504 /* just sent a rcv wnd 0 */
1505 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1506 /* constrained to send ack */
1507 || (tc->flags & TCP_CONN_SNDACK) != 0
1508 /* we're almost out of tx wnd */
1509 || tcp_available_snd_space (tc) < 4 * tc->snd_mss)
1516 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1518 u32 discard, first = b->current_length;
1519 vlib_main_t *vm = vlib_get_main ();
1521 /* Handle multi-buffer segments */
1522 if (n_bytes_to_drop > b->current_length)
1524 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1528 discard = clib_min (n_bytes_to_drop, b->current_length);
1529 vlib_buffer_advance (b, discard);
1530 b = vlib_get_buffer (vm, b->next_buffer);
1531 n_bytes_to_drop -= discard;
1533 while (n_bytes_to_drop);
1534 if (n_bytes_to_drop > first)
1535 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1538 vlib_buffer_advance (b, n_bytes_to_drop);
1539 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1544 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1547 u32 error = 0, n_bytes_to_drop, n_data_bytes;
1549 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1550 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1551 ASSERT (n_data_bytes);
1553 /* Handle out-of-order data */
1554 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1556 /* Old sequence numbers allowed through because they overlapped
1558 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1560 error = TCP_ERROR_SEGMENT_OLD;
1561 *next0 = tcp_next_drop (tc->c_is_ip4);
1563 /* Completely in the past (possible retransmit) */
1564 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1566 /* Ack retransmissions since we may not have any data to send */
1567 tcp_make_ack (tc, b);
1568 *next0 = tcp_next_output (tc->c_is_ip4);
1572 /* Chop off the bytes in the past */
1573 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1574 n_data_bytes -= n_bytes_to_drop;
1575 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1576 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1582 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1584 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1585 * cwnd on remote peer when congested 2) acks leaving should have the
1586 * latest rcv_wnd since the burst may eaten up all of it, so only the
1587 * old ones could be filtered.
1590 /* RFC2581: Send DUPACK for fast retransmit */
1591 tcp_make_ack (tc, b);
1592 *next0 = tcp_next_output (tc->c_is_ip4);
1594 /* Mark as DUPACK. We may filter these in output if
1595 * the burst fills the holes. */
1597 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1599 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1605 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1606 * segments can be enqueued after fifo tail offset changes. */
1607 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1609 /* Check if ACK can be delayed */
1610 if (tcp_can_delack (tc))
1612 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1613 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1617 *next0 = tcp_next_output (tc->c_is_ip4);
1618 tcp_make_ack (tc, b);
1626 tcp_header_t tcp_header;
1627 tcp_connection_t tcp_connection;
1631 format_tcp_rx_trace (u8 * s, va_list * args)
1633 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1634 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1635 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1636 u32 indent = format_get_indent (s);
1638 s = format (s, "%U\n%U%U",
1639 format_tcp_header, &t->tcp_header, 128,
1640 format_white_space, indent,
1641 format_tcp_connection, &t->tcp_connection, 1);
1647 format_tcp_rx_trace_short (u8 * s, va_list * args)
1649 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1650 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1651 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1653 s = format (s, "%d -> %d (%U)",
1654 clib_net_to_host_u16 (t->tcp_header.src_port),
1655 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1656 t->tcp_connection.state);
1662 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1663 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1667 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1671 th0 = tcp_buffer_hdr (b0);
1673 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1677 tcp_node_inc_counter (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1678 u8 is_ip4, u8 evt, u8 val)
1680 if (PREDICT_TRUE (!val))
1684 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1686 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1690 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1691 vlib_frame_t * from_frame, int is_ip4)
1693 u32 n_left_from, next_index, *from, *to_next;
1694 u32 my_thread_index = vm->thread_index, errors = 0;
1695 tcp_main_t *tm = vnet_get_tcp_main ();
1698 from = vlib_frame_vector_args (from_frame);
1699 n_left_from = from_frame->n_vectors;
1701 next_index = node->cached_next_index;
1703 while (n_left_from > 0)
1707 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1708 while (n_left_from > 0 && n_left_to_next > 0)
1712 tcp_header_t *th0 = 0;
1713 tcp_connection_t *tc0;
1714 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
1721 n_left_to_next -= 1;
1723 b0 = vlib_get_buffer (vm, bi0);
1724 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1727 if (PREDICT_FALSE (tc0 == 0))
1729 error0 = TCP_ERROR_INVALID_CONNECTION;
1733 th0 = tcp_buffer_hdr (b0);
1734 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1735 * dangling reference. */
1736 is_fin = tcp_is_fin (th0);
1738 /* SYNs, FINs and data consume sequence numbers */
1739 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1740 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1742 /* TODO header prediction fast path */
1744 /* 1-4: check SEQ, RST, SYN */
1745 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1747 error0 = TCP_ERROR_SEGMENT_INVALID;
1748 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1749 vnet_buffer (b0)->tcp.seq_number,
1750 vnet_buffer (b0)->tcp.seq_end);
1754 /* 5: check the ACK field */
1755 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1758 /* 6: check the URG bit TODO */
1760 /* 7: process the segment text */
1761 if (vnet_buffer (b0)->tcp.data_len)
1762 error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
1764 /* 8: check the FIN bit */
1765 if (PREDICT_FALSE (is_fin))
1767 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1768 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1769 /* Account for the FIN if nothing else was received */
1770 if (vnet_buffer (b0)->tcp.data_len == 0)
1772 tcp_make_ack (tc0, b0);
1773 next0 = tcp_next_output (tc0->c_is_ip4);
1774 tc0->state = TCP_STATE_CLOSE_WAIT;
1775 stream_session_disconnect_notify (&tc0->connection);
1776 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1777 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1781 b0->error = node->errors[error0];
1782 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1784 tcp_rx_trace_t *t0 =
1785 vlib_add_trace (vm, node, b0, sizeof (*t0));
1786 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1789 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1790 n_left_to_next, bi0, next0);
1793 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1796 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
1798 tcp_node_inc_counter (vm, is_ip4, tcp4_established_node.index,
1799 tcp6_established_node.index,
1800 TCP_ERROR_EVENT_FIFO_FULL, errors);
1801 tcp_flush_frame_to_output (vm, my_thread_index, is_ip4);
1803 return from_frame->n_vectors;
1807 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1808 vlib_frame_t * from_frame)
1810 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1814 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1815 vlib_frame_t * from_frame)
1817 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1821 VLIB_REGISTER_NODE (tcp4_established_node) =
1823 .function = tcp4_established,
1824 .name = "tcp4-established",
1825 /* Takes a vector of packets. */
1826 .vector_size = sizeof (u32),
1827 .n_errors = TCP_N_ERROR,
1828 .error_strings = tcp_error_strings,
1829 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1832 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1833 foreach_tcp_state_next
1836 .format_trace = format_tcp_rx_trace_short,
1840 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1843 VLIB_REGISTER_NODE (tcp6_established_node) =
1845 .function = tcp6_established,
1846 .name = "tcp6-established",
1847 /* Takes a vector of packets. */
1848 .vector_size = sizeof (u32),
1849 .n_errors = TCP_N_ERROR,
1850 .error_strings = tcp_error_strings,
1851 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1854 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1855 foreach_tcp_state_next
1858 .format_trace = format_tcp_rx_trace_short,
1863 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1865 vlib_node_registration_t tcp4_syn_sent_node;
1866 vlib_node_registration_t tcp6_syn_sent_node;
1869 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
1871 transport_connection_t *tmp = 0;
1878 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
1881 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
1882 && (tc->state == TCP_STATE_LISTEN
1883 || tc->c_rmt_port == hdr->src_port));
1887 handle = session_lookup_half_open_handle (&tc->connection);
1888 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
1889 tc->c_proto, tc->c_is_ip4);
1893 if (tmp->lcl_port == hdr->dst_port
1894 && tmp->rmt_port == hdr->src_port)
1896 TCP_DBG ("half-open is valid!");
1904 * Lookup transport connection
1906 static tcp_connection_t *
1907 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
1911 transport_connection_t *tconn;
1912 tcp_connection_t *tc;
1917 ip4 = vlib_buffer_get_current (b);
1918 tcp = ip4_next_header (ip4);
1919 tconn = session_lookup_connection_wt4 (fib_index,
1924 TRANSPORT_PROTO_TCP,
1925 thread_index, &is_filtered);
1926 tc = tcp_get_connection_from_transport (tconn);
1927 ASSERT (tcp_lookup_is_valid (tc, tcp));
1932 ip6 = vlib_buffer_get_current (b);
1933 tcp = ip6_next_header (ip6);
1934 tconn = session_lookup_connection_wt6 (fib_index,
1939 TRANSPORT_PROTO_TCP,
1940 thread_index, &is_filtered);
1941 tc = tcp_get_connection_from_transport (tconn);
1942 ASSERT (tcp_lookup_is_valid (tc, tcp));
1948 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1949 vlib_frame_t * from_frame, int is_ip4)
1951 tcp_main_t *tm = vnet_get_tcp_main ();
1952 u32 n_left_from, next_index, *from, *to_next;
1953 u32 my_thread_index = vm->thread_index, errors = 0;
1955 from = vlib_frame_vector_args (from_frame);
1956 n_left_from = from_frame->n_vectors;
1958 next_index = node->cached_next_index;
1960 while (n_left_from > 0)
1964 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1966 while (n_left_from > 0 && n_left_to_next > 0)
1968 u32 bi0, ack0, seq0;
1971 tcp_header_t *tcp0 = 0;
1972 tcp_connection_t *tc0;
1973 tcp_connection_t *new_tc0;
1974 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
1981 n_left_to_next -= 1;
1983 b0 = vlib_get_buffer (vm, bi0);
1985 tcp_half_open_connection_get (vnet_buffer (b0)->
1986 tcp.connection_index);
1987 if (PREDICT_FALSE (tc0 == 0))
1989 error0 = TCP_ERROR_INVALID_CONNECTION;
1993 /* Half-open completed recently but the connection was't removed
1994 * yet by the owning thread */
1995 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
1997 /* Make sure the connection actually exists */
1998 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
1999 my_thread_index, is_ip4));
2003 ack0 = vnet_buffer (b0)->tcp.ack_number;
2004 seq0 = vnet_buffer (b0)->tcp.seq_number;
2005 tcp0 = tcp_buffer_hdr (b0);
2007 /* Crude check to see if the connection handle does not match
2008 * the packet. Probably connection just switched to established */
2009 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2010 || tcp0->src_port != tc0->c_rmt_port))
2014 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
2017 /* SYNs, FINs and data consume sequence numbers */
2018 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
2019 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
2022 * 1. check the ACK bit
2026 * If the ACK bit is set
2027 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2028 * the RST bit is set, if so drop the segment and return)
2029 * <SEQ=SEG.ACK><CTL=RST>
2030 * and discard the segment. Return.
2031 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2035 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2037 clib_warning ("ack not in rcv wnd");
2038 if (!tcp_rst (tcp0))
2039 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2043 /* Make sure ACK is valid */
2044 if (seq_gt (tc0->snd_una, ack0))
2046 clib_warning ("ack invalid");
2052 * 2. check the RST bit
2057 /* If ACK is acceptable, signal client that peer is not
2058 * willing to accept connection and drop connection*/
2060 tcp_connection_reset (tc0);
2065 * 3. check the security and precedence (skipped)
2069 * 4. check the SYN bit
2072 /* No SYN flag. Drop. */
2073 if (!tcp_syn (tcp0))
2075 clib_warning ("not synack");
2080 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2082 clib_warning ("options parse fail");
2086 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2087 * current thread pool. */
2088 pool_get (tm->connections[my_thread_index], new_tc0);
2089 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2090 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2091 new_tc0->c_thread_index = my_thread_index;
2092 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2093 new_tc0->irs = seq0;
2094 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2095 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2096 TCP_TIMER_HANDLE_INVALID;
2098 /* If this is not the owning thread, wait for syn retransmit to
2099 * expire and cleanup then */
2100 if (tcp_half_open_connection_cleanup (tc0))
2101 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2103 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2105 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2106 new_tc0->tsval_recent_age = tcp_time_now ();
2109 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2110 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2112 /* RFC1323: SYN and SYN-ACK wnd not scaled */
2113 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
2114 new_tc0->snd_wl1 = seq0;
2115 new_tc0->snd_wl2 = ack0;
2117 tcp_connection_init_vars (new_tc0);
2119 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2120 if (PREDICT_TRUE (tcp_ack (tcp0)))
2122 /* Our SYN is ACKed: we have iss < ack = snd_una */
2124 /* TODO Dequeue acknowledged segments if we support Fast Open */
2125 new_tc0->snd_una = ack0;
2126 new_tc0->state = TCP_STATE_ESTABLISHED;
2128 /* Make sure las is initialized for the wnd computation */
2129 new_tc0->rcv_las = new_tc0->rcv_nxt;
2131 /* Notify app that we have connection. If session layer can't
2132 * allocate session send reset */
2133 if (session_stream_connect_notify (&new_tc0->connection, 0))
2135 clib_warning ("connect notify fail");
2136 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2137 tcp_connection_cleanup (new_tc0);
2141 /* Make sure after data segment processing ACK is sent */
2142 new_tc0->flags |= TCP_CONN_SNDACK;
2144 /* Update rtt with the syn-ack sample */
2145 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2146 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2148 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2151 new_tc0->state = TCP_STATE_SYN_RCVD;
2153 /* Notify app that we have connection */
2154 if (session_stream_connect_notify (&new_tc0->connection, 0))
2156 tcp_connection_cleanup (new_tc0);
2157 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2158 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2163 tcp_init_snd_vars (tc0);
2164 tcp_make_synack (new_tc0, b0);
2165 next0 = tcp_next_output (is_ip4);
2170 /* Read data, if any */
2171 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2174 error0 = tcp_segment_rcv (tm, new_tc0, b0, &next0);
2175 if (error0 == TCP_ERROR_PURE_ACK)
2176 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2180 tcp_make_ack (new_tc0, b0);
2181 next0 = tcp_next_output (new_tc0->c_is_ip4);
2186 b0->error = error0 ? node->errors[error0] : 0;
2188 ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2190 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2191 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2192 clib_memcpy (&t0->tcp_connection, tc0,
2193 sizeof (t0->tcp_connection));
2196 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2197 n_left_to_next, bi0, next0);
2200 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2203 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2205 tcp_node_inc_counter (vm, is_ip4, tcp4_syn_sent_node.index,
2206 tcp6_syn_sent_node.index,
2207 TCP_ERROR_EVENT_FIFO_FULL, errors);
2208 return from_frame->n_vectors;
2212 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2213 vlib_frame_t * from_frame)
2215 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2219 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2220 vlib_frame_t * from_frame)
2222 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2226 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2228 .function = tcp4_syn_sent,
2229 .name = "tcp4-syn-sent",
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_SYN_SENT_N_NEXT,
2237 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2238 foreach_tcp_state_next
2241 .format_trace = format_tcp_rx_trace_short,
2245 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2248 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2250 .function = tcp6_syn_sent_rcv,
2251 .name = "tcp6-syn-sent",
2252 /* Takes a vector of packets. */
2253 .vector_size = sizeof (u32),
2254 .n_errors = TCP_N_ERROR,
2255 .error_strings = tcp_error_strings,
2256 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2259 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2260 foreach_tcp_state_next
2263 .format_trace = format_tcp_rx_trace_short,
2267 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2269 vlib_node_registration_t tcp4_rcv_process_node;
2270 vlib_node_registration_t tcp6_rcv_process_node;
2273 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2274 * as per RFC793 p. 64
2277 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2278 vlib_frame_t * from_frame, int is_ip4)
2280 tcp_main_t *tm = vnet_get_tcp_main ();
2281 u32 n_left_from, next_index, *from, *to_next;
2282 u32 my_thread_index = vm->thread_index, errors = 0;
2284 from = vlib_frame_vector_args (from_frame);
2285 n_left_from = from_frame->n_vectors;
2287 next_index = node->cached_next_index;
2289 while (n_left_from > 0)
2293 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2295 while (n_left_from > 0 && n_left_to_next > 0)
2299 tcp_header_t *tcp0 = 0;
2300 tcp_connection_t *tc0;
2301 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
2309 n_left_to_next -= 1;
2311 b0 = vlib_get_buffer (vm, bi0);
2312 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2314 if (PREDICT_FALSE (tc0 == 0))
2316 error0 = TCP_ERROR_INVALID_CONNECTION;
2320 tcp0 = tcp_buffer_hdr (b0);
2321 is_fin0 = tcp_is_fin (tcp0);
2323 /* SYNs, FINs and data consume sequence numbers */
2324 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2325 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2329 tcp_connection_t *tmp;
2331 tcp_lookup_connection (tc0->c_fib_index, b0, my_thread_index,
2333 if (tmp->state != tc0->state)
2335 clib_warning ("state changed");
2342 * Special treatment for CLOSED
2346 case TCP_STATE_CLOSED:
2352 * For all other states (except LISTEN)
2355 /* 1-4: check SEQ, RST, SYN */
2356 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2359 error0 = TCP_ERROR_SEGMENT_INVALID;
2363 /* 5: check the ACK field */
2366 case TCP_STATE_SYN_RCVD:
2368 * If the segment acknowledgment is not acceptable, form a
2370 * <SEQ=SEG.ACK><CTL=RST>
2373 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2375 TCP_DBG ("connection not accepted");
2376 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2380 /* Update rtt and rto */
2381 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2383 /* Switch state to ESTABLISHED */
2384 tc0->state = TCP_STATE_ESTABLISHED;
2385 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2387 /* Initialize session variables */
2388 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2389 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2390 << tc0->rcv_opts.wscale;
2391 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2392 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2394 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2395 tcp_retransmit_timer_reset (tc0);
2396 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2398 stream_session_accept_notify (&tc0->connection);
2400 case TCP_STATE_ESTABLISHED:
2401 /* We can get packets in established state here because they
2402 * were enqueued before state change */
2403 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2407 case TCP_STATE_FIN_WAIT_1:
2408 /* In addition to the processing for the ESTABLISHED state, if
2409 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2410 * continue processing in that state. */
2411 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2414 /* Still have to send the FIN */
2415 if (tc0->flags & TCP_CONN_FINPNDG)
2417 /* TX fifo finally drained */
2418 if (!stream_session_tx_fifo_max_dequeue (&tc0->connection))
2421 /* If FIN is ACKed */
2422 else if (tc0->snd_una == tc0->snd_una_max)
2424 tc0->state = TCP_STATE_FIN_WAIT_2;
2425 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2427 /* Stop all retransmit timers because we have nothing more
2428 * to send. Enable waitclose though because we're willing to
2429 * wait for peer's FIN but not indefinitely. */
2430 tcp_connection_timers_reset (tc0);
2431 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2434 case TCP_STATE_FIN_WAIT_2:
2435 /* In addition to the processing for the ESTABLISHED state, if
2436 * the retransmission queue is empty, the user's CLOSE can be
2437 * acknowledged ("ok") but do not delete the TCB. */
2438 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2441 case TCP_STATE_CLOSE_WAIT:
2442 /* Do the same processing as for the ESTABLISHED state. */
2443 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2446 case TCP_STATE_CLOSING:
2447 /* In addition to the processing for the ESTABLISHED state, if
2448 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2449 * otherwise ignore the segment. */
2450 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2453 tc0->state = TCP_STATE_TIME_WAIT;
2454 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2455 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2459 case TCP_STATE_LAST_ACK:
2460 /* The only thing that [should] arrive in this state is an
2461 * acknowledgment of our FIN. If our FIN is now acknowledged,
2462 * delete the TCB, enter the CLOSED state, and return. */
2464 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2466 error0 = TCP_ERROR_ACK_INVALID;
2470 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2471 /* Apparently our ACK for the peer's FIN was lost */
2472 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2478 tc0->state = TCP_STATE_CLOSED;
2479 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2480 tcp_connection_timers_reset (tc0);
2482 /* Don't delete the connection/session yet. Instead, wait a
2483 * reasonable amount of time until the pipes are cleared. In
2484 * particular, this makes sure that we won't have dead sessions
2485 * when processing events on the tx path */
2486 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2491 case TCP_STATE_TIME_WAIT:
2492 /* The only thing that can arrive in this state is a
2493 * retransmission of the remote FIN. Acknowledge it, and restart
2494 * the 2 MSL timeout. */
2496 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2499 tcp_make_ack (tc0, b0);
2500 next0 = tcp_next_output (is_ip4);
2501 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2510 /* 6: check the URG bit TODO */
2512 /* 7: process the segment text */
2515 case TCP_STATE_ESTABLISHED:
2516 case TCP_STATE_FIN_WAIT_1:
2517 case TCP_STATE_FIN_WAIT_2:
2518 if (vnet_buffer (b0)->tcp.data_len)
2519 error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
2523 case TCP_STATE_CLOSE_WAIT:
2524 case TCP_STATE_CLOSING:
2525 case TCP_STATE_LAST_ACK:
2526 case TCP_STATE_TIME_WAIT:
2527 /* This should not occur, since a FIN has been received from the
2528 * remote side. Ignore the segment text. */
2532 /* 8: check the FIN bit */
2538 case TCP_STATE_ESTABLISHED:
2539 case TCP_STATE_SYN_RCVD:
2540 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2541 tcp_connection_timers_reset (tc0);
2542 tcp_make_fin (tc0, b0);
2544 next0 = tcp_next_output (tc0->c_is_ip4);
2545 stream_session_disconnect_notify (&tc0->connection);
2546 tc0->state = TCP_STATE_CLOSE_WAIT;
2547 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2549 case TCP_STATE_CLOSE_WAIT:
2550 case TCP_STATE_CLOSING:
2551 case TCP_STATE_LAST_ACK:
2554 case TCP_STATE_FIN_WAIT_1:
2555 tc0->state = TCP_STATE_CLOSING;
2556 tcp_make_ack (tc0, b0);
2557 next0 = tcp_next_output (is_ip4);
2558 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2559 /* Wait for ACK but not forever */
2560 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2562 case TCP_STATE_FIN_WAIT_2:
2563 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2564 tc0->state = TCP_STATE_TIME_WAIT;
2565 tcp_connection_timers_reset (tc0);
2566 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2567 tcp_make_ack (tc0, b0);
2568 next0 = tcp_next_output (is_ip4);
2569 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2571 case TCP_STATE_TIME_WAIT:
2572 /* Remain in the TIME-WAIT state. Restart the time-wait
2575 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2578 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2581 b0->error = error0 ? node->errors[error0] : 0;
2583 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2585 tcp_rx_trace_t *t0 =
2586 vlib_add_trace (vm, node, b0, sizeof (*t0));
2587 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2590 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2591 n_left_to_next, bi0, next0);
2594 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2597 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2599 tcp_node_inc_counter (vm, is_ip4, tcp4_rcv_process_node.index,
2600 tcp6_rcv_process_node.index,
2601 TCP_ERROR_EVENT_FIFO_FULL, errors);
2603 return from_frame->n_vectors;
2607 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2608 vlib_frame_t * from_frame)
2610 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2614 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2615 vlib_frame_t * from_frame)
2617 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2621 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2623 .function = tcp4_rcv_process,
2624 .name = "tcp4-rcv-process",
2625 /* Takes a vector of packets. */
2626 .vector_size = sizeof (u32),
2627 .n_errors = TCP_N_ERROR,
2628 .error_strings = tcp_error_strings,
2629 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2632 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2633 foreach_tcp_state_next
2636 .format_trace = format_tcp_rx_trace_short,
2640 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2643 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2645 .function = tcp6_rcv_process,
2646 .name = "tcp6-rcv-process",
2647 /* Takes a vector of packets. */
2648 .vector_size = sizeof (u32),
2649 .n_errors = TCP_N_ERROR,
2650 .error_strings = tcp_error_strings,
2651 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2654 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2655 foreach_tcp_state_next
2658 .format_trace = format_tcp_rx_trace_short,
2662 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2664 vlib_node_registration_t tcp4_listen_node;
2665 vlib_node_registration_t tcp6_listen_node;
2668 * LISTEN state processing as per RFC 793 p. 65
2671 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2672 vlib_frame_t * from_frame, int is_ip4)
2674 u32 n_left_from, next_index, *from, *to_next;
2675 u32 my_thread_index = vm->thread_index;
2677 from = vlib_frame_vector_args (from_frame);
2678 n_left_from = from_frame->n_vectors;
2680 next_index = node->cached_next_index;
2682 while (n_left_from > 0)
2686 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2688 while (n_left_from > 0 && n_left_to_next > 0)
2693 tcp_header_t *th0 = 0;
2694 tcp_connection_t *lc0;
2697 tcp_connection_t *child0;
2698 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = tcp_next_drop (is_ip4);
2705 n_left_to_next -= 1;
2707 b0 = vlib_get_buffer (vm, bi0);
2708 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2712 ip40 = vlib_buffer_get_current (b0);
2713 th0 = ip4_next_header (ip40);
2717 ip60 = vlib_buffer_get_current (b0);
2718 th0 = ip6_next_header (ip60);
2721 /* Create child session. For syn-flood protection use filter */
2723 /* 1. first check for an RST: handled in dispatch */
2724 /* if (tcp_rst (th0))
2727 /* 2. second check for an ACK: handled in dispatch */
2728 /* if (tcp_ack (th0))
2730 tcp_send_reset (b0, is_ip4);
2734 /* 3. check for a SYN (did that already) */
2736 /* Make sure connection wasn't just created */
2738 tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
2740 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
2742 error0 = TCP_ERROR_CREATE_EXISTS;
2746 /* Create child session and send SYN-ACK */
2747 child0 = tcp_connection_new (my_thread_index);
2748 child0->c_lcl_port = th0->dst_port;
2749 child0->c_rmt_port = th0->src_port;
2750 child0->c_is_ip4 = is_ip4;
2751 child0->state = TCP_STATE_SYN_RCVD;
2755 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2756 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2760 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2761 sizeof (ip6_address_t));
2762 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2763 sizeof (ip6_address_t));
2766 if (tcp_options_parse (th0, &child0->rcv_opts))
2768 clib_warning ("options parse fail");
2772 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2773 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2774 child0->rcv_las = child0->rcv_nxt;
2776 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2777 * segments are used to initialize PAWS. */
2778 if (tcp_opts_tstamp (&child0->rcv_opts))
2780 child0->tsval_recent = child0->rcv_opts.tsval;
2781 child0->tsval_recent_age = tcp_time_now ();
2784 if (tcp_opts_wscale (&child0->rcv_opts))
2785 child0->snd_wscale = child0->rcv_opts.wscale;
2787 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2788 << child0->snd_wscale;
2789 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2790 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2792 tcp_connection_init_vars (child0);
2793 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
2795 if (stream_session_accept (&child0->connection, lc0->c_s_index,
2798 clib_warning ("session accept fail");
2799 tcp_connection_cleanup (child0);
2800 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2804 /* Reuse buffer to make syn-ack and send */
2805 tcp_make_synack (child0, b0);
2806 next0 = tcp_next_output (is_ip4);
2807 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
2810 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2812 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2813 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2814 clib_memcpy (&t0->tcp_connection, lc0,
2815 sizeof (t0->tcp_connection));
2818 b0->error = node->errors[error0];
2820 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2821 n_left_to_next, bi0, next0);
2824 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2826 return from_frame->n_vectors;
2830 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2831 vlib_frame_t * from_frame)
2833 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2837 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2838 vlib_frame_t * from_frame)
2840 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2844 VLIB_REGISTER_NODE (tcp4_listen_node) =
2846 .function = tcp4_listen,
2847 .name = "tcp4-listen",
2848 /* Takes a vector of packets. */
2849 .vector_size = sizeof (u32),
2850 .n_errors = TCP_N_ERROR,
2851 .error_strings = tcp_error_strings,
2852 .n_next_nodes = TCP_LISTEN_N_NEXT,
2855 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2856 foreach_tcp_state_next
2859 .format_trace = format_tcp_rx_trace_short,
2863 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2866 VLIB_REGISTER_NODE (tcp6_listen_node) =
2868 .function = tcp6_listen,
2869 .name = "tcp6-listen",
2870 /* Takes a vector of packets. */
2871 .vector_size = sizeof (u32),
2872 .n_errors = TCP_N_ERROR,
2873 .error_strings = tcp_error_strings,
2874 .n_next_nodes = TCP_LISTEN_N_NEXT,
2877 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2878 foreach_tcp_state_next
2881 .format_trace = format_tcp_rx_trace_short,
2885 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2887 vlib_node_registration_t tcp4_input_node;
2888 vlib_node_registration_t tcp6_input_node;
2890 typedef enum _tcp_input_next
2892 TCP_INPUT_NEXT_DROP,
2893 TCP_INPUT_NEXT_LISTEN,
2894 TCP_INPUT_NEXT_RCV_PROCESS,
2895 TCP_INPUT_NEXT_SYN_SENT,
2896 TCP_INPUT_NEXT_ESTABLISHED,
2897 TCP_INPUT_NEXT_RESET,
2898 TCP_INPUT_NEXT_PUNT,
2902 #define foreach_tcp4_input_next \
2903 _ (DROP, "ip4-drop") \
2904 _ (LISTEN, "tcp4-listen") \
2905 _ (RCV_PROCESS, "tcp4-rcv-process") \
2906 _ (SYN_SENT, "tcp4-syn-sent") \
2907 _ (ESTABLISHED, "tcp4-established") \
2908 _ (RESET, "tcp4-reset") \
2909 _ (PUNT, "ip4-punt")
2911 #define foreach_tcp6_input_next \
2912 _ (DROP, "ip6-drop") \
2913 _ (LISTEN, "tcp6-listen") \
2914 _ (RCV_PROCESS, "tcp6-rcv-process") \
2915 _ (SYN_SENT, "tcp6-syn-sent") \
2916 _ (ESTABLISHED, "tcp6-established") \
2917 _ (RESET, "tcp6-reset") \
2918 _ (PUNT, "ip6-punt")
2920 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2923 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2924 vlib_frame_t * from_frame, int is_ip4)
2926 u32 n_left_from, next_index, *from, *to_next;
2927 u32 my_thread_index = vm->thread_index;
2928 tcp_main_t *tm = vnet_get_tcp_main ();
2930 from = vlib_frame_vector_args (from_frame);
2931 n_left_from = from_frame->n_vectors;
2932 next_index = node->cached_next_index;
2933 tcp_set_time_now (my_thread_index);
2935 while (n_left_from > 0)
2939 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2941 while (n_left_from > 0 && n_left_to_next > 0)
2943 int n_advance_bytes0, n_data_bytes0;
2944 u32 bi0, fib_index0;
2946 tcp_header_t *tcp0 = 0;
2947 tcp_connection_t *tc0;
2948 transport_connection_t *tconn;
2951 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2952 u8 flags0, is_filtered = 0;
2959 n_left_to_next -= 1;
2961 b0 = vlib_get_buffer (vm, bi0);
2962 vnet_buffer (b0)->tcp.flags = 0;
2963 fib_index0 = vnet_buffer (b0)->ip.fib_index;
2965 /* Checksum computed by ipx_local no need to compute again */
2969 ip40 = vlib_buffer_get_current (b0);
2970 tcp0 = ip4_next_header (ip40);
2971 n_advance_bytes0 = (ip4_header_bytes (ip40)
2972 + tcp_header_bytes (tcp0));
2973 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2975 tconn = session_lookup_connection_wt4 (fib_index0,
2980 TRANSPORT_PROTO_TCP,
2986 ip60 = vlib_buffer_get_current (b0);
2987 tcp0 = ip6_next_header (ip60);
2988 n_advance_bytes0 = tcp_header_bytes (tcp0);
2989 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2991 n_advance_bytes0 += sizeof (ip60[0]);
2992 tconn = session_lookup_connection_wt6 (fib_index0,
2997 TRANSPORT_PROTO_TCP,
3003 if (PREDICT_FALSE (n_advance_bytes0 < 0))
3005 error0 = TCP_ERROR_LENGTH;
3009 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
3010 - (u8 *) vlib_buffer_get_current (b0);
3012 /* Session exists */
3013 if (PREDICT_TRUE (0 != tconn))
3015 tc0 = tcp_get_connection_from_transport (tconn);
3016 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
3018 /* Save connection index */
3019 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
3020 vnet_buffer (b0)->tcp.seq_number =
3021 clib_net_to_host_u32 (tcp0->seq_number);
3022 vnet_buffer (b0)->tcp.ack_number =
3023 clib_net_to_host_u32 (tcp0->ack_number);
3025 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
3026 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
3028 flags0 = tcp0->flags & filter_flags;
3029 next0 = tm->dispatch_table[tc0->state][flags0].next;
3030 error0 = tm->dispatch_table[tc0->state][flags0].error;
3032 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH
3033 || next0 == TCP_INPUT_NEXT_RESET))
3035 /* Overload tcp flags to store state */
3036 tcp_state_t state0 = tc0->state;
3037 vnet_buffer (b0)->tcp.flags = tc0->state;
3039 if (error0 == TCP_ERROR_DISPATCH)
3040 clib_warning ("disp error state %U flags %U",
3041 format_tcp_state, state0, format_tcp_flags,
3049 next0 = TCP_INPUT_NEXT_DROP;
3050 error0 = TCP_ERROR_FILTERED;
3052 else if ((is_ip4 && tm->punt_unknown4) ||
3053 (!is_ip4 && tm->punt_unknown6))
3055 next0 = TCP_INPUT_NEXT_PUNT;
3056 error0 = TCP_ERROR_PUNT;
3061 next0 = TCP_INPUT_NEXT_RESET;
3062 error0 = TCP_ERROR_NO_LISTENER;
3068 b0->error = error0 ? node->errors[error0] : 0;
3070 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3073 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3074 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3076 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
3077 n_left_to_next, bi0, next0);
3080 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3083 return from_frame->n_vectors;
3087 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3088 vlib_frame_t * from_frame)
3090 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3094 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3095 vlib_frame_t * from_frame)
3097 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3101 VLIB_REGISTER_NODE (tcp4_input_node) =
3103 .function = tcp4_input,
3104 .name = "tcp4-input",
3105 /* Takes a vector of packets. */
3106 .vector_size = sizeof (u32),
3107 .n_errors = TCP_N_ERROR,
3108 .error_strings = tcp_error_strings,
3109 .n_next_nodes = TCP_INPUT_N_NEXT,
3112 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3113 foreach_tcp4_input_next
3116 .format_buffer = format_tcp_header,
3117 .format_trace = format_tcp_rx_trace,
3121 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3124 VLIB_REGISTER_NODE (tcp6_input_node) =
3126 .function = tcp6_input,
3127 .name = "tcp6-input",
3128 /* Takes a vector of packets. */
3129 .vector_size = sizeof (u32),
3130 .n_errors = TCP_N_ERROR,
3131 .error_strings = tcp_error_strings,
3132 .n_next_nodes = TCP_INPUT_N_NEXT,
3135 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3136 foreach_tcp6_input_next
3139 .format_buffer = format_tcp_header,
3140 .format_trace = format_tcp_rx_trace,
3144 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3147 tcp_dispatch_table_init (tcp_main_t * tm)
3150 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3151 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3153 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3154 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3157 #define _(t,f,n,e) \
3159 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3160 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3163 /* SYNs for new connections -> tcp-listen. */
3164 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3165 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3166 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_NONE);
3167 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3169 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3170 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3171 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3172 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3173 /* SYN-ACK for a SYN */
3174 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3176 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3177 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3178 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3180 /* ACK for for established connection -> tcp-established. */
3181 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3182 /* FIN for for established connection -> tcp-established. */
3183 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3184 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3186 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3187 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3189 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3190 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3192 /* ACK or FIN-ACK to our FIN */
3193 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3194 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3196 /* FIN in reply to our FIN from the other side */
3197 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3198 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3199 /* FIN confirming that the peer (app) has closed */
3200 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3201 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3202 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3204 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3205 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3207 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3208 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3209 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3211 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3212 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3213 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3215 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3216 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3217 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3218 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3219 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3220 TCP_ERROR_CONNECTION_CLOSED);
3225 tcp_input_init (vlib_main_t * vm)
3227 clib_error_t *error = 0;
3228 tcp_main_t *tm = vnet_get_tcp_main ();
3230 if ((error = vlib_call_init_function (vm, tcp_init)))
3233 /* Initialize dispatch table. */
3234 tcp_dispatch_table_init (tm);
3239 VLIB_INIT_FUNCTION (tcp_input_init);
3242 * fd.io coding-style-patch-verification: ON
3245 * eval: (c-set-style "gnu")