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 buf->buflen += ((minlen / 256) + 1) * 256;
22 buf->buf = realloc(buf->buf, buf->buflen);
27 blob_init(struct blob_attr *attr, int id, unsigned int len)
29 len &= BLOB_ATTR_LEN_MASK;
30 len |= (id << BLOB_ATTR_ID_SHIFT) & BLOB_ATTR_ID_MASK;
31 attr->id_len = cpu_to_be32(len);
34 static inline struct blob_attr *
35 offset_to_attr(struct blob_buf *buf, int offset)
37 void *ptr = (char *)buf->buf + offset;
42 attr_to_offset(struct blob_buf *buf, struct blob_attr *attr)
44 return (char *)attr - (char *) buf->buf;
47 static struct blob_attr *
48 blob_add(struct blob_buf *buf, struct blob_attr *pos, int id, int payload)
50 int offset = attr_to_offset(buf, pos);
51 int required = (offset + sizeof(struct blob_attr) + payload) - buf->buflen;
52 struct blob_attr *attr;
55 int offset_head = attr_to_offset(buf, buf->head);
57 if (!buf->grow || !buf->grow(buf, required))
60 buf->head = offset_to_attr(buf, offset_head);
61 attr = offset_to_attr(buf, offset);
66 blob_init(attr, id, payload + sizeof(struct blob_attr));
71 blob_buf_init(struct blob_buf *buf, int id)
74 buf->grow = blob_buffer_grow;
77 if (blob_add(buf, buf->buf, id, 0) == NULL)
84 blob_buf_free(struct blob_buf *buf)
92 blob_new(struct blob_buf *buf, int id, int payload)
94 struct blob_attr *attr;
96 attr = blob_add(buf, blob_next(buf->head), id, payload);
100 blob_set_raw_len(buf->head, blob_pad_len(buf->head) + blob_pad_len(attr));
105 blob_put(struct blob_buf *buf, int id, const void *ptr, int len)
107 struct blob_attr *attr;
109 attr = blob_new(buf, id, len);
114 memcpy(blob_data(attr), ptr, len);
119 blob_nest_start(struct blob_buf *buf, int id)
121 unsigned long offset = attr_to_offset(buf, buf->head);
122 buf->head = blob_new(buf, id, 0);
123 return (void *) offset;
127 blob_nest_end(struct blob_buf *buf, void *cookie)
129 struct blob_attr *attr = offset_to_attr(buf, (unsigned long) cookie);
130 blob_set_raw_len(attr, blob_pad_len(attr) + blob_len(buf->head));
134 static const int blob_type_minlen[BLOB_ATTR_LAST] = {
135 [BLOB_ATTR_STRING] = 1,
136 [BLOB_ATTR_INT8] = sizeof(uint8_t),
137 [BLOB_ATTR_INT16] = sizeof(uint16_t),
138 [BLOB_ATTR_INT32] = sizeof(uint32_t),
139 [BLOB_ATTR_INT64] = sizeof(uint64_t),
143 blob_check_type(const void *ptr, int len, int type)
145 const char *data = ptr;
147 if (type >= BLOB_ATTR_LAST)
150 if (type >= BLOB_ATTR_INT8 && type <= BLOB_ATTR_INT64) {
151 if (len != blob_type_minlen[type])
154 if (len < blob_type_minlen[type])
158 if (type == BLOB_ATTR_STRING && data[len - 1] != 0)
165 blob_parse(struct blob_attr *attr, struct blob_attr **data, const struct blob_attr_info *info, int max)
167 struct blob_attr *pos;
171 memset(data, 0, sizeof(struct blob_attr *) * max);
172 blob_for_each_attr(pos, attr, rem) {
173 int id = blob_id(pos);
174 int len = blob_len(pos);
180 int type = info[id].type;
182 if (type < BLOB_ATTR_LAST) {
183 if (!blob_check_type(blob_data(pos), len, type))
187 if (info[id].minlen && len < info[id].minlen)
190 if (info[id].maxlen && len > info[id].maxlen)
193 if (info[id].validate && !info[id].validate(&info[id], attr))