Line data Source code
1 : #include "fd_quic_ack_tx.h"
2 : #include "fd_quic_private.h"
3 :
4 : #include "fd_quic_proto.h"
5 : #include "fd_quic_proto.c"
6 :
7 : static inline int
8 : fd_quic_range_can_extend( fd_quic_range_t const * range,
9 80928446 : ulong idx ) {
10 80928446 : return idx+1UL >= range->offset_lo && idx <= range->offset_hi;
11 80928446 : }
12 :
13 : static inline int
14 : fd_quic_range_extend( fd_quic_range_t * range,
15 80603787 : ulong idx ) {
16 80603787 : int lo_decreased = idx < range->offset_lo;
17 80603787 : int hi_increased = idx >= range->offset_hi;
18 80603787 : range->offset_lo = fd_ulong_min( range->offset_lo, idx );
19 80603787 : range->offset_hi = fd_ulong_max( range->offset_hi, idx+1UL );
20 80603787 : return lo_decreased || hi_increased;
21 80603787 : }
22 :
23 : int
24 : fd_quic_ack_pkt( fd_quic_ack_gen_t * gen,
25 : ulong pkt_number,
26 : uint enc_level,
27 80928452 : long now ) {
28 :
29 80928452 : if( pkt_number == FD_QUIC_PKT_NUM_UNUSED ) return FD_QUIC_ACK_TX_NOOP;
30 :
31 : /* Can we merge pkt_number into the most recent ACK? */
32 80928446 : uint cached_seq = gen->head - 1U;
33 80928446 : fd_quic_ack_t * cached_ack = fd_quic_ack_queue_ele( gen, cached_seq );
34 80928446 : if( ( enc_level == cached_ack->enc_level ) &
35 80928446 : fd_quic_range_can_extend( &cached_ack->pkt_number, pkt_number ) ) {
36 :
37 : /* update timestamp */
38 80603787 : if( pkt_number >= cached_ack->pkt_number.offset_hi ) {
39 80603775 : cached_ack->ts = now;
40 80603775 : }
41 :
42 : /* add packet number to existing range */
43 80603787 : int changed = fd_quic_range_extend( &cached_ack->pkt_number, pkt_number );
44 :
45 : /* re-enqueue most recent ACK for sending */
46 80603787 : if( changed && gen->head==gen->tail ) {
47 301157 : gen->tail = cached_seq;
48 301157 : }
49 :
50 80603787 : FD_ACK_DEBUG( FD_LOG_DEBUG(( "gen=%p queue ACK for enc=%u pkt_num=%lu range=[%lu,%lu) seq=%u (merged)",
51 80603787 : (void *)gen, enc_level, pkt_number, cached_ack->pkt_number.offset_lo, cached_ack->pkt_number.offset_hi, cached_seq )); )
52 80603787 : return FD_QUIC_ACK_TX_MERGED;
53 :
54 80603787 : }
55 :
56 : /* Attempt to allocate another ACK queue entry */
57 324659 : if( gen->head - gen->tail >= FD_QUIC_ACK_QUEUE_CNT ) {
58 3 : FD_DEBUG( FD_LOG_DEBUG(( "ACK queue overflow! (excessive reordering)" )); )
59 3 : return FD_QUIC_ACK_TX_ENOSPC;
60 3 : }
61 :
62 : /* Start new pending ACK */
63 324656 : FD_ACK_DEBUG( FD_LOG_DEBUG(( "gen=%p queue ACK for enc=%u pkt_num=%lu seq=%u",
64 324656 : (void *)gen, enc_level, pkt_number, gen->head )); )
65 324656 : fd_quic_ack_t * next_ack = fd_quic_ack_queue_ele( gen, gen->head );
66 324656 : *next_ack = (fd_quic_ack_t) {
67 324656 : .pkt_number = { .offset_lo = pkt_number, .offset_hi = pkt_number+1UL },
68 324656 : .enc_level = (uchar)enc_level,
69 324656 : .ts = now
70 324656 : };
71 324656 : gen->head += 1U;
72 324656 : return FD_QUIC_ACK_TX_NEW;
73 324659 : }
74 :
75 : void
76 : fd_quic_ack_gen_abandon_enc_level( fd_quic_ack_gen_t * gen,
77 24240 : uint enc_level ) {
78 36360 : for( ; gen->tail != gen->head; gen->tail++ ) {
79 18180 : fd_quic_ack_t const * ack = fd_quic_ack_queue_ele( gen, gen->tail );
80 18180 : if( ack->enc_level > enc_level ) break;
81 18180 : FD_DEBUG( FD_LOG_DEBUG(( "gen=%p discard ACK for enc=%u range=[%lu,%lu) seq=%u",
82 18180 : (void *)gen, enc_level, ack->pkt_number.offset_lo, ack->pkt_number.offset_hi, gen->tail )); )
83 18180 : }
84 24240 : }
85 :
86 : extern ulong
87 : fd_quic_encode_ack_frame( uchar * buf,
88 : ulong sz,
89 : fd_quic_ack_frame_t * frame );
90 :
91 : uchar *
92 : fd_quic_gen_ack_frames( fd_quic_ack_gen_t * gen,
93 : uchar * payload_ptr,
94 : uchar * payload_end,
95 : uint enc_level,
96 18731899 : long now ) {
97 :
98 18731899 : FD_ACK_DEBUG( FD_LOG_DEBUG(( "[ACK gen] elicited=%d", gen->is_elicited )); )
99 : /* Never generate an ACK frame if no ACK-eliciting packet is pending.
100 : This prevents an infinite ACK loop. */
101 18731899 : if( !gen->is_elicited ) return payload_ptr;
102 :
103 : /* Attempt to send all ACK ranges */
104 319307 : ulong ranges_sent = 0UL;
105 632539 : for( ; gen->tail != gen->head; gen->tail++ ) {
106 319316 : fd_quic_ack_t * ack = fd_quic_ack_queue_ele( gen, gen->tail );
107 319316 : if( ack->enc_level != enc_level ) {
108 6066 : FD_ACK_DEBUG( FD_LOG_DEBUG(( "need encryption level %u for ACKs but have %u", ack->enc_level, enc_level )); )
109 6066 : break;
110 6066 : }
111 :
112 313250 : long ack_delay_ns = fd_long_sat_sub( now, ack->ts );
113 313250 : long ack_delay_us = ack_delay_ns / (long)1e3;
114 :
115 313250 : if( FD_UNLIKELY( ack->pkt_number.offset_lo == ack->pkt_number.offset_hi ) ) continue;
116 313250 : fd_quic_ack_frame_t ack_frame = {
117 313250 : .type = 0x02, /* type 0x02 is the base ack, 0x03 indicates ECN */
118 313250 : .largest_ack = ack->pkt_number.offset_hi - 1U,
119 313250 : .ack_delay = (ulong)ack_delay_us,
120 313250 : .ack_range_count = 0, /* no fragments */
121 313250 : .first_ack_range = ack->pkt_number.offset_hi - ack->pkt_number.offset_lo - 1U,
122 313250 : };
123 313250 : ulong frame_sz = fd_quic_encode_ack_frame( payload_ptr, (ulong)( payload_end - payload_ptr ), &ack_frame );
124 313250 : if( FD_UNLIKELY( frame_sz==FD_QUIC_ENCODE_FAIL ) ) {
125 18 : FD_DEBUG( FD_LOG_DEBUG(( "insufficient buffer space to send ACK" )); )
126 18 : break;
127 18 : }
128 313232 : payload_ptr += frame_sz;
129 313232 : ranges_sent += 1UL;
130 313232 : FD_ACK_DEBUG( FD_LOG_DEBUG(( "gen=%p sending ACK enc=%u range=[%lu,%lu) seq=%u sz=%lu",
131 313232 : (void *)gen, enc_level, ack->pkt_number.offset_lo, ack->pkt_number.offset_hi, gen->tail, frame_sz )); )
132 313232 : }
133 :
134 : /* If all frames were flushed, reset status bits. */
135 319307 : if( gen->head == gen->tail ) {
136 313223 : gen->is_elicited = 0;
137 313223 : } else {
138 6084 : FD_ACK_DEBUG( FD_LOG_DEBUG(( "Not all ACK frames were flushed" )); )
139 6084 : }
140 :
141 319307 : int const flushed = !gen->is_elicited;
142 319307 : FD_DTRACE_PROBE_3( fd_quic_gen_ack_frames, enc_level, ranges_sent, flushed );
143 :
144 319307 : return payload_ptr;
145 18731899 : }
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