summaryrefslogtreecommitdiffstats
path: root/include/haproxy/hpack-tbl.h
blob: 02cf7db5432239991e23d2dfc89e526d20bd679f (plain)
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
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
/*
 * HPACK header table management (RFC7541) - prototypes
 *
 * Copyright (C) 2014-2020 Willy Tarreau <willy@haproxy.org>
 * Copyright (C) 2017 HAProxy Technologies
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */
#ifndef _HAPROXY_HPACK_TBL_H
#define _HAPROXY_HPACK_TBL_H

#include <import/ist.h>
#include <haproxy/api.h>
#include <haproxy/hpack-tbl-t.h>
#include <haproxy/http-hdr-t.h>

/* when built outside of haproxy, HPACK_STANDALONE must be defined, and
 * pool_head_hpack_tbl->size must be set to the DHT size.
 */
#ifndef HPACK_STANDALONE
#include <haproxy/pool.h>
#define hpack_alloc(pool)      pool_alloc(pool)
#define hpack_free(pool, ptr)  pool_free(pool, ptr)
#else
#include <stdlib.h>
#include <haproxy/pool-t.h>
#define hpack_alloc(pool)      malloc(pool->size)
#define hpack_free(pool, ptr)  free(ptr)
#endif

extern const struct http_hdr hpack_sht[HPACK_SHT_SIZE];
extern struct pool_head *pool_head_hpack_tbl;

int __hpack_dht_make_room(struct hpack_dht *dht, unsigned int needed);
int hpack_dht_insert(struct hpack_dht *dht, struct ist name, struct ist value);

#ifdef DEBUG_HPACK
void hpack_dht_dump(FILE *out, const struct hpack_dht *dht);
void hpack_dht_check_consistency(const struct hpack_dht *dht);
#endif

/* return a pointer to the entry designated by index <idx> (starting at 1) or
 * NULL if this index is not there.
 */
static inline const struct hpack_dte *hpack_get_dte(const struct hpack_dht *dht, uint16_t idx)
{
	idx--;

	if (idx >= dht->used)
		return NULL;

	if (idx <= dht->head)
		idx = dht->head - idx;
	else
		idx = dht->head - idx + dht->wrap;

	return &dht->dte[idx];
}

/* returns non-zero if <idx> is valid for table <dht> */
static inline int hpack_valid_idx(const struct hpack_dht *dht, uint32_t idx)
{
	return idx < dht->used + HPACK_SHT_SIZE;
}

/* return a pointer to the header name for entry <dte>. */
static inline struct ist hpack_get_name(const struct hpack_dht *dht, const struct hpack_dte *dte)
{
	struct ist ret = {
		.ptr = (void *)dht + dte->addr,
		.len = dte->nlen,
	};
	return ret;
}

/* return a pointer to the header value for entry <dte>. */
static inline struct ist hpack_get_value(const struct hpack_dht *dht, const struct hpack_dte *dte)
{
	struct ist ret = {
		.ptr = (void *)dht + dte->addr + dte->nlen,
		.len = dte->vlen,
	};
	return ret;
}

/* takes an idx, returns the associated name */
static inline struct ist hpack_idx_to_name(const struct hpack_dht *dht, uint32_t idx)
{
	const struct hpack_dte *dte;

	if (idx < HPACK_SHT_SIZE)
		return hpack_sht[idx].n;

	dte = hpack_get_dte(dht, idx - HPACK_SHT_SIZE + 1);
	if (!dte)
		return ist("### ERR ###"); // error

	return hpack_get_name(dht, dte);
}

/* takes an idx, returns the associated value */
static inline struct ist hpack_idx_to_value(const struct hpack_dht *dht, uint32_t idx)
{
	const struct hpack_dte *dte;

	if (idx < HPACK_SHT_SIZE)
		return hpack_sht[idx].v;

	dte = hpack_get_dte(dht, idx - HPACK_SHT_SIZE + 1);
	if (!dte)
		return ist("### ERR ###"); // error

	return hpack_get_value(dht, dte);
}

/* returns the slot number of the oldest entry (tail). Must not be used on an
 * empty table.
 */
static inline unsigned int hpack_dht_get_tail(const struct hpack_dht *dht)
{
	return ((dht->head + 1U < dht->used) ? dht->wrap : 0) + dht->head + 1U - dht->used;
}

/* Purges table dht until a header field of <needed> bytes fits according to
 * the protocol (adding 32 bytes overhead). Returns non-zero on success, zero
 * on failure (ie: table empty but still not sufficient).
 */
static inline int hpack_dht_make_room(struct hpack_dht *dht, unsigned int needed)
{
	if (dht->used * 32 + dht->total + needed + 32 <= dht->size)
		return 1;
	else if (!dht->used)
		return 0;

	return __hpack_dht_make_room(dht, needed);
}

/* allocate a dynamic headers table of <size> bytes and return it initialized */
static inline void hpack_dht_init(struct hpack_dht *dht, uint32_t size)
{
	dht->size = size;
	dht->total = 0;
	dht->used = 0;
}

/* allocate a dynamic headers table from the pool and return it initialized */
static inline struct hpack_dht *hpack_dht_alloc()
{
	struct hpack_dht *dht;

	if (unlikely(!pool_head_hpack_tbl))
		return NULL;

	dht = hpack_alloc(pool_head_hpack_tbl);
	if (dht)
		hpack_dht_init(dht, pool_head_hpack_tbl->size);
	return dht;
}

/* free a dynamic headers table */
static inline void hpack_dht_free(struct hpack_dht *dht)
{
	hpack_free(pool_head_hpack_tbl, dht);
}

#endif /* _HAPROXY_HPACK_TBL_H */