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/*
* blob - library for generating/parsing tagged binary data
*
* Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License version 2.1
* as published by the Free Software Foundation
*
* 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.
*/
#include "blob.h"
static bool
blob_buffer_grow(struct blob_buf *buf, int minlen)
{
buf->buflen += ((minlen / 256) + 1) * 256;
buf->buf = realloc(buf->buf, buf->buflen);
return !!buf->buf;
}
static void
blob_init(struct blob_attr *attr, int id, unsigned int len)
{
len &= BLOB_ATTR_LEN_MASK;
len |= (id << BLOB_ATTR_ID_SHIFT) & BLOB_ATTR_ID_MASK;
attr->id_len = cpu_to_be32(len);
}
static inline struct blob_attr *
offset_to_attr(struct blob_buf *buf, int offset)
{
void *ptr = (char *)buf->buf + offset;
return ptr;
}
static inline int
attr_to_offset(struct blob_buf *buf, struct blob_attr *attr)
{
return (char *)attr - (char *) buf->buf;
}
static struct blob_attr *
blob_add(struct blob_buf *buf, struct blob_attr *pos, int id, int payload)
{
int offset = attr_to_offset(buf, pos);
int required = (offset + sizeof(struct blob_attr) + payload) - buf->buflen;
struct blob_attr *attr;
if (required > 0) {
int offset_head = attr_to_offset(buf, buf->head);
if (!buf->grow || !buf->grow(buf, required))
return NULL;
buf->head = offset_to_attr(buf, offset_head);
attr = offset_to_attr(buf, offset);
} else {
attr = pos;
}
blob_init(attr, id, payload + sizeof(struct blob_attr));
return attr;
}
int
blob_buf_init(struct blob_buf *buf, int id)
{
if (!buf->grow)
buf->grow = blob_buffer_grow;
buf->head = buf->buf;
if (blob_add(buf, buf->buf, id, 0) == NULL)
return -ENOMEM;
return 0;
}
struct blob_attr *
blob_new(struct blob_buf *buf, int id, int payload)
{
struct blob_attr *attr;
attr = blob_add(buf, blob_next(buf->head), id, payload);
if (!attr)
return NULL;
blob_set_raw_len(buf->head, blob_pad_len(buf->head) + blob_pad_len(attr));
return attr;
}
struct blob_attr *
blob_put(struct blob_buf *buf, int id, const void *ptr, int len)
{
struct blob_attr *attr;
attr = blob_new(buf, id, len);
if (!attr)
return NULL;
if (ptr)
memcpy(blob_data(attr), ptr, len);
return attr;
}
void *
blob_nest_start(struct blob_buf *buf, int id)
{
unsigned long offset = attr_to_offset(buf, buf->head);
buf->head = blob_new(buf, id, 0);
return (void *) offset;
}
void
blob_nest_end(struct blob_buf *buf, void *cookie)
{
struct blob_attr *attr = offset_to_attr(buf, (unsigned long) cookie);
blob_set_raw_len(attr, blob_pad_len(attr) + blob_len(buf->head));
buf->head = attr;
}
static const int blob_type_minlen[BLOB_ATTR_LAST] = {
[BLOB_ATTR_STRING] = 1,
[BLOB_ATTR_INT8] = sizeof(uint8_t),
[BLOB_ATTR_INT16] = sizeof(uint16_t),
[BLOB_ATTR_INT32] = sizeof(uint32_t),
[BLOB_ATTR_INT64] = sizeof(uint64_t),
};
int
blob_parse(struct blob_attr *attr, struct blob_attr **data, const struct blob_attr_info *info, int max)
{
struct blob_attr *pos;
int found = 0;
int rem;
memset(data, 0, sizeof(struct blob_attr *) * max);
blob_for_each_attr(pos, attr, rem) {
int id = blob_id(pos);
int len = blob_len(pos);
if (id >= max)
continue;
if (info) {
int type = info[id].type;
if (type < BLOB_ATTR_LAST) {
if (type >= BLOB_ATTR_INT8 && type <= BLOB_ATTR_INT64) {
if (len != blob_type_minlen[type])
continue;
} else {
if (len < blob_type_minlen[type])
continue;
}
}
if (info[id].minlen && len < info[id].minlen)
continue;
if (info[id].maxlen && len > info[id].maxlen)
continue;
if (info[id].validate && !info[id].validate(&info[id], attr))
continue;
}
if (!data[id])
found++;
data[id] = pos;
}
return found;
}
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