1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
|
/* Copyright (C) 2022 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
/*!
* \file
*
* \brief TCP buffer helpers.
*
* \addtogroup xdp
* @{
*/
#pragma once
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <sys/uio.h>
typedef struct knot_tcp_outbuf {
struct knot_tcp_outbuf *next;
uint32_t len;
uint32_t seqno;
bool sent;
uint8_t bytes[];
} knot_tcp_outbuf_t;
typedef enum {
KNOT_SWEEP_CTR_TIMEOUT = 0,
KNOT_SWEEP_CTR_LIMIT_CONN = 1,
KNOT_SWEEP_CTR_LIMIT_IBUF = 2,
KNOT_SWEEP_CTR_LIMIT_OBUF = 3,
} knot_sweep_counter_t;
typedef struct knot_sweep_stats {
uint32_t total;
uint32_t counters[4];
} knot_sweep_stats_t;
inline static void knot_sweep_stats_incr(knot_sweep_stats_t *stats, knot_sweep_counter_t counter)
{
(stats->counters[counter])++;
(stats->total)++;
}
inline static void knot_sweep_stats_reset(knot_sweep_stats_t *stats)
{
memset(stats, 0, sizeof(*stats));
}
/*!
* \brief Handle DNS-over-TCP payloads in buffer and message.
*
* \param buffer In/out: persistent buffer to store incomplete DNS payloads between receiving packets.
* \param data In: momental DNS payloads in incoming packet.
* \param inbufs Out: list of incoming DNS messages.
* \param inbufs_count Out: number of inbufs.
* \param buffers_total In/Out: total size of buffers (will be increased or decreased).
*
* \return KNOT_EOK, KNOT_ENOMEM
*/
int knot_tcp_inbuf_update(struct iovec *buffer, struct iovec data,
struct iovec **inbufs, size_t *inbufs_count,
size_t *buffers_total);
/*!
* \brief Add payload to be sent by TCP, to output buffers.
*
* \param bufs Output buffers to be updated.
* \param data Payload to be sent.
* \param len Payload length.
* \param ignore_lastbyte Evil mode: drop last byte of the payload.
* \param mss Connection outgoing MSS.
* \param outbufs_total In/out: total outbuf statistic to be updated.
*
* \return KNOT_E*
*/
int knot_tcp_outbufs_add(knot_tcp_outbuf_t **bufs, uint8_t *data, size_t len,
bool ignore_lastbyte, uint32_t mss, size_t *outbufs_total);
/*!
* \brief Remove+free acked data from output buffers.
*
* \param bufs Output buffers to be updated.
* \param ackno Ackno of received ACK.
* \param outbufs_total In/out: total outbuf statistic to be updated.
*/
void knot_tcp_outbufs_ack(knot_tcp_outbuf_t **bufs, uint32_t ackno, size_t *outbufs_total);
/*!
* \brief Prepare output buffers to be sent now.
*
* \param bufs Output buffers to be updated.
* \param window_size Connection outgoing window size.
* \param resend Send also possibly already sent data.
* \param send_start Out: first output buffer to be sent.
* \param send_count Out: number of output buffers to be sent.
*/
void knot_tcp_outbufs_can_send(knot_tcp_outbuf_t *bufs, ssize_t window_size, bool resend,
knot_tcp_outbuf_t **send_start, size_t *send_count);
/*!
* \brief Compute allocated size of output buffers.
*/
size_t knot_tcp_outbufs_usage(knot_tcp_outbuf_t *bufs);
/*! @} */
|
