2 * blob - library for generating/parsing tagged binary data
4 * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU Lesser General Public License version 2.1
8 * as published by the Free Software Foundation
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
19 blob_buffer_grow(struct blob_buf
*buf
, int minlen
)
21 int delta
= ((minlen
/ 256) + 1) * 256;
23 buf
->buf
= realloc(buf
->buf
, buf
->buflen
);
25 memset(buf
->buf
+ buf
->buflen
- delta
, 0, delta
);
30 blob_init(struct blob_attr
*attr
, int id
, unsigned int len
)
32 len
&= BLOB_ATTR_LEN_MASK
;
33 len
|= (id
<< BLOB_ATTR_ID_SHIFT
) & BLOB_ATTR_ID_MASK
;
34 attr
->id_len
= cpu_to_be32(len
);
37 static inline struct blob_attr
*
38 offset_to_attr(struct blob_buf
*buf
, int offset
)
40 void *ptr
= (char *)buf
->buf
+ offset
;
45 attr_to_offset(struct blob_buf
*buf
, struct blob_attr
*attr
)
47 return (char *)attr
- (char *) buf
->buf
;
50 static struct blob_attr
*
51 blob_add(struct blob_buf
*buf
, struct blob_attr
*pos
, int id
, int payload
)
53 int offset
= attr_to_offset(buf
, pos
);
54 int required
= (offset
+ sizeof(struct blob_attr
) + payload
) - buf
->buflen
;
55 struct blob_attr
*attr
;
58 int offset_head
= attr_to_offset(buf
, buf
->head
);
60 if (!buf
->grow
|| !buf
->grow(buf
, required
))
63 buf
->head
= offset_to_attr(buf
, offset_head
);
64 attr
= offset_to_attr(buf
, offset
);
69 blob_init(attr
, id
, payload
+ sizeof(struct blob_attr
));
74 blob_buf_init(struct blob_buf
*buf
, int id
)
77 buf
->grow
= blob_buffer_grow
;
80 if (blob_add(buf
, buf
->buf
, id
, 0) == NULL
)
87 blob_buf_free(struct blob_buf
*buf
)
95 blob_fill_pad(struct blob_attr
*attr
)
97 char *buf
= (char *) attr
;
98 int len
= blob_pad_len(attr
);
99 int delta
= len
- blob_raw_len(attr
);
102 memset(buf
+ len
- delta
, 0, delta
);
106 blob_set_raw_len(struct blob_attr
*attr
, unsigned int len
)
108 int id
= blob_id(attr
);
109 len
&= BLOB_ATTR_LEN_MASK
;
110 len
|= (id
<< BLOB_ATTR_ID_SHIFT
) & BLOB_ATTR_ID_MASK
;
111 attr
->id_len
= cpu_to_be32(len
);
116 blob_new(struct blob_buf
*buf
, int id
, int payload
)
118 struct blob_attr
*attr
;
120 attr
= blob_add(buf
, blob_next(buf
->head
), id
, payload
);
124 blob_set_raw_len(buf
->head
, blob_pad_len(buf
->head
) + blob_pad_len(attr
));
129 blob_put(struct blob_buf
*buf
, int id
, const void *ptr
, int len
)
131 struct blob_attr
*attr
;
133 attr
= blob_new(buf
, id
, len
);
138 memcpy(blob_data(attr
), ptr
, len
);
143 blob_nest_start(struct blob_buf
*buf
, int id
)
145 unsigned long offset
= attr_to_offset(buf
, buf
->head
);
146 buf
->head
= blob_new(buf
, id
, 0);
147 return (void *) offset
;
151 blob_nest_end(struct blob_buf
*buf
, void *cookie
)
153 struct blob_attr
*attr
= offset_to_attr(buf
, (unsigned long) cookie
);
154 blob_set_raw_len(attr
, blob_pad_len(attr
) + blob_len(buf
->head
));
158 static const int blob_type_minlen
[BLOB_ATTR_LAST
] = {
159 [BLOB_ATTR_STRING
] = 1,
160 [BLOB_ATTR_INT8
] = sizeof(uint8_t),
161 [BLOB_ATTR_INT16
] = sizeof(uint16_t),
162 [BLOB_ATTR_INT32
] = sizeof(uint32_t),
163 [BLOB_ATTR_INT64
] = sizeof(uint64_t),
167 blob_check_type(const void *ptr
, int len
, int type
)
169 const char *data
= ptr
;
171 if (type
>= BLOB_ATTR_LAST
)
174 if (type
>= BLOB_ATTR_INT8
&& type
<= BLOB_ATTR_INT64
) {
175 if (len
!= blob_type_minlen
[type
])
178 if (len
< blob_type_minlen
[type
])
182 if (type
== BLOB_ATTR_STRING
&& data
[len
- 1] != 0)
189 blob_parse(struct blob_attr
*attr
, struct blob_attr
**data
, const struct blob_attr_info
*info
, int max
)
191 struct blob_attr
*pos
;
195 memset(data
, 0, sizeof(struct blob_attr
*) * max
);
196 blob_for_each_attr(pos
, attr
, rem
) {
197 int id
= blob_id(pos
);
198 int len
= blob_len(pos
);
204 int type
= info
[id
].type
;
206 if (type
< BLOB_ATTR_LAST
) {
207 if (!blob_check_type(blob_data(pos
), len
, type
))
211 if (info
[id
].minlen
&& len
< info
[id
].minlen
)
214 if (info
[id
].maxlen
&& len
> info
[id
].maxlen
)
217 if (info
[id
].validate
&& !info
[id
].validate(&info
[id
], attr
))
230 blob_attr_equal(const struct blob_attr
*a1
, const struct blob_attr
*a2
)
238 if (blob_pad_len(a1
) != blob_pad_len(a2
))
241 return !memcmp(a1
, a2
, blob_pad_len(a1
));