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/* lib9p/internal.h - TODO
*
* Copyright (C) 2024 Luke T. Shumaker <lukeshu@lukeshu.com>
* SPDX-Licence-Identifier: AGPL-3.0-or-later
*/
#ifndef _LIB9P_INTERNAL_H_
#define _LIB9P_INTERNAL_H_
#include <assert.h>
#include <stddef.h> /* for size_t */
#include <limits.h> /* for SSIZE_MAX */
#include <lib9p/9p.h>
#define USE_CONFIG_9P
#include "config.h"
static_assert(CONFIG_9P_MAX_ERR_SIZE <= UINT16_MAX);
static_assert(CONFIG_9P_MAX_MSG_SIZE <= SSIZE_MAX);
/* C language *****************************************************************/
#define UNUSED(name) /* name __attribute__ ((unused)) */
/* types **********************************************************************/
/* NB: We declare this here instead of in the public <lib9p/9p.h>
* because we don't want to include "config.h" from public headers,
* and I want the MAX_ERR_SIZE to be configurable. */
struct lib9p_ctx {
/* negotiated */
enum lib9p_version version;
uint32_t max_msg_size;
/* negotiated (server) */
uint32_t Rerror_overhead;
/* state */
uint32_t err_num;
char err_msg[CONFIG_9P_MAX_ERR_SIZE];
};
/* vtables ********************************************************************/
struct _checksize_ctx {
struct lib9p_ctx *ctx;
uint32_t net_size;
uint8_t *net_bytes;
uint32_t net_offset;
/* Increment `host_extra` to pre-allocate space that is
* "extra" beyond sizeof(). */
size_t host_extra;
};
struct _unmarshal_ctx {
struct lib9p_ctx *ctx;
uint8_t *net_bytes;
uint32_t net_offset;
/* `extra` points to the beginning of unallocated space. */
void *extra;
};
struct _marshal_ctx {
struct lib9p_ctx *ctx;
uint8_t *net_bytes;
uint32_t net_offset;
};
typedef bool (*_checksize_fn_t)(struct _checksize_ctx *ctx);
typedef void (*_unmarshal_fn_t)(struct _unmarshal_ctx *ctx, void *out);
typedef bool (*_marshal_fn_t)(struct _marshal_ctx *ctx, void *host_val);
struct _vtable_msg {
size_t unmarshal_basesize;
_checksize_fn_t unmarshal_extrasize;
_unmarshal_fn_t unmarshal;
_marshal_fn_t marshal;
};
struct _vtable_version {
struct _vtable_msg msgs[0xFF];
};
extern struct _vtable_version _lib9p_vtables[LIB9P_VER_NUM];
/* unmarshal utilities ********************************************************/
static inline uint8_t decode_u8le(uint8_t *in) {
return in[0];
}
static inline uint16_t decode_u16le(uint8_t *in) {
return (((uint16_t)(in[0])) << 0)
| (((uint16_t)(in[1])) << 8)
;
}
static inline uint32_t decode_u32le(uint8_t *in) {
return (((uint32_t)(in[0])) << 0)
| (((uint32_t)(in[1])) << 8)
| (((uint32_t)(in[2])) << 16)
| (((uint32_t)(in[3])) << 24)
;
}
static inline uint64_t decode_u64le(uint8_t *in) {
return (((uint64_t)(in[0])) << 0)
| (((uint64_t)(in[1])) << 8)
| (((uint64_t)(in[2])) << 16)
| (((uint64_t)(in[3])) << 24)
| (((uint64_t)(in[4])) << 32)
| (((uint64_t)(in[5])) << 40)
| (((uint64_t)(in[6])) << 48)
| (((uint64_t)(in[7])) << 56)
;
}
static inline bool _is_valid_utf8(uint8_t *str, size_t len, bool forbid_nul) {
uint32_t ch;
uint8_t chlen;
assert(str);
for (size_t pos = 0; pos < len;) {
if ((str[pos] & 0b10000000) == 0b00000000) { ch = str[pos] & 0b01111111; chlen = 1; }
else if ((str[pos] & 0b11100000) == 0b11000000) { ch = str[pos] & 0b00011111; chlen = 2; }
else if ((str[pos] & 0b11110000) == 0b11100000) { ch = str[pos] & 0b00001111; chlen = 3; }
else if ((str[pos] & 0b11111000) == 0b11110000) { ch = str[pos] & 0b00000111; chlen = 4; }
else return false;
if ((ch == 0 && (chlen != 1 || forbid_nul)) || pos + chlen > len) return false;
for (uint8_t i = 1; i < chlen; i++) {
if ((str[pos+i] & 0b11000000) != 0b10000000) return false;
ch = (ch << 6) | (str[pos+i] & 0b00111111);
}
if (ch > 0x10FFFF) return false;
pos += chlen;
}
return true;
}
#define is_valid_utf8(str, len) _is_valid_utf8(str, len, false)
#define is_valid_utf8_without_nul(str, len) _is_valid_utf8(str, len, true)
/* marshal utilities **********************************************************/
static inline void encode_u8le(uint8_t in, uint8_t *out) {
out[0] = in;
}
static inline void encode_u16le(uint16_t in, uint8_t *out) {
out[0] = (uint8_t)((in >> 0) & 0xFF);
out[1] = (uint8_t)((in >> 8) & 0xFF);
}
static inline void encode_u32le(uint32_t in, uint8_t *out) {
out[0] = (uint8_t)((in >> 0) & 0xFF);
out[1] = (uint8_t)((in >> 8) & 0xFF);
out[2] = (uint8_t)((in >> 16) & 0xFF);
out[3] = (uint8_t)((in >> 24) & 0xFF);
}
static inline void encode_u64le(uint64_t in, uint8_t *out) {
out[0] = (uint8_t)((in >> 0) & 0xFF);
out[1] = (uint8_t)((in >> 8) & 0xFF);
out[2] = (uint8_t)((in >> 16) & 0xFF);
out[3] = (uint8_t)((in >> 24) & 0xFF);
out[4] = (uint8_t)((in >> 32) & 0xFF);
out[5] = (uint8_t)((in >> 40) & 0xFF);
out[6] = (uint8_t)((in >> 48) & 0xFF);
out[7] = (uint8_t)((in >> 56) & 0xFF);
}
#endif /* _LIB9P_INTERNAL_H_ */
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