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_new(struct blob_buf *buf, int id, int payload)
97 struct blob_attr *attr;
99 attr = blob_add(buf, blob_next(buf->head), id, payload);
103 blob_set_raw_len(buf->head, blob_pad_len(buf->head) + blob_pad_len(attr));
108 blob_put(struct blob_buf *buf, int id, const void *ptr, int len)
110 struct blob_attr *attr;
112 attr = blob_new(buf, id, len);
117 memcpy(blob_data(attr), ptr, len);
122 blob_nest_start(struct blob_buf *buf, int id)
124 unsigned long offset = attr_to_offset(buf, buf->head);
125 buf->head = blob_new(buf, id, 0);
126 return (void *) offset;
130 blob_nest_end(struct blob_buf *buf, void *cookie)
132 struct blob_attr *attr = offset_to_attr(buf, (unsigned long) cookie);
133 blob_set_raw_len(attr, blob_pad_len(attr) + blob_len(buf->head));
137 static const int blob_type_minlen[BLOB_ATTR_LAST] = {
138 [BLOB_ATTR_STRING] = 1,
139 [BLOB_ATTR_INT8] = sizeof(uint8_t),
140 [BLOB_ATTR_INT16] = sizeof(uint16_t),
141 [BLOB_ATTR_INT32] = sizeof(uint32_t),
142 [BLOB_ATTR_INT64] = sizeof(uint64_t),
146 blob_check_type(const void *ptr, int len, int type)
148 const char *data = ptr;
150 if (type >= BLOB_ATTR_LAST)
153 if (type >= BLOB_ATTR_INT8 && type <= BLOB_ATTR_INT64) {
154 if (len != blob_type_minlen[type])
157 if (len < blob_type_minlen[type])
161 if (type == BLOB_ATTR_STRING && data[len - 1] != 0)
168 blob_parse(struct blob_attr *attr, struct blob_attr **data, const struct blob_attr_info *info, int max)
170 struct blob_attr *pos;
174 memset(data, 0, sizeof(struct blob_attr *) * max);
175 blob_for_each_attr(pos, attr, rem) {
176 int id = blob_id(pos);
177 int len = blob_len(pos);
183 int type = info[id].type;
185 if (type < BLOB_ATTR_LAST) {
186 if (!blob_check_type(blob_data(pos), len, type))
190 if (info[id].minlen && len < info[id].minlen)
193 if (info[id].maxlen && len > info[id].maxlen)
196 if (info[id].validate && !info[id].validate(&info[id], attr))
209 blob_attr_equal(const struct blob_attr *a1, const struct blob_attr *a2)
217 if (blob_pad_len(a1) != blob_pad_len(a2))
220 return !memcmp(a1, a2, blob_pad_len(a1));