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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 2019 Ettus Research, a National Instruments Brand
*/
#include <string.h>
#include "tlv_eeprom.h"
struct tlv_eeprom *tlv_eeprom_init(void *data)
{
struct tlv_eeprom *e = data;
return e;
}
void tlv_eeprom_seal(struct tlv_eeprom *e, uint32_t magic, size_t len)
{
e->magic = magic;
e->size = len;
e->crc = tlv_eeprom_crc(e);
}
int tlv_eeprom_validate(const struct tlv_eeprom *e, uint32_t magic)
{
uint32_t crc;
if (e->magic != magic)
return -1;
if (e->size > TLV_EEPROM_SIZE)
return -2;
crc = tlv_eeprom_crc(e);
if (e->crc != crc)
return -3;
return 0;
}
struct tlv {
uint8_t tag;
uint8_t len;
uint8_t val[0];
};
static inline const struct tlv *tlv_next(const struct tlv *tlv, const void *end)
{
const void *p = &tlv->val;
p += tlv->len;
if (p >= end)
return NULL;
return p;
}
static inline const struct tlv *tlv_find(const struct tlv *tlv,
const void *end, uint8_t tag)
{
do {
if (tlv->tag == tag)
break;
} while ((tlv = tlv_next(tlv, end)));
return tlv;
}
void tlv_for_each(const void *buf, size_t bufsz,
void (*fn)(uint8_t tag, uint8_t len, const void *val))
{
const struct tlv *tlv = buf;
do {
fn(tlv->tag, tlv->len, tlv->val);
} while ((tlv = tlv_next(tlv, buf + bufsz)));
}
const void *tlv_lookup(const void *buf, size_t bufsz, uint8_t tag)
{
const struct tlv *tlv;
tlv = tlv_find(buf, buf + bufsz, tag);
if (!tlv)
return tlv;
return tlv->val;
}
size_t tlv_write(void *buf, uint8_t tag, uint8_t len, const void *val)
{
struct tlv *tlv = buf;
tlv->tag = tag;
tlv->len = len;
memcpy(tlv->val, val, len);
return sizeof(*tlv) + len;
}
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