2 * blob - library for generating/parsing tagged binary data
4 * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
6 * Permission to use, copy, modify, and/or distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22 blob_buffer_grow(struct blob_buf *buf, int minlen)
24 int delta = ((minlen / 256) + 1) * 256;
26 buf->buf = realloc(buf->buf, buf->buflen);
28 memset(buf->buf + buf->buflen - delta, 0, delta);
33 blob_init(struct blob_attr *attr, int id, unsigned int len)
35 len &= BLOB_ATTR_LEN_MASK;
36 len |= (id << BLOB_ATTR_ID_SHIFT) & BLOB_ATTR_ID_MASK;
37 attr->id_len = cpu_to_be32(len);
40 static inline struct blob_attr *
41 offset_to_attr(struct blob_buf *buf, int offset)
43 void *ptr = (char *)buf->buf + offset;
48 attr_to_offset(struct blob_buf *buf, struct blob_attr *attr)
50 return (char *)attr - (char *) buf->buf;
54 blob_buf_grow(struct blob_buf *buf, int required)
56 int offset_head = attr_to_offset(buf, buf->head);
58 if (!buf->grow || !buf->grow(buf, required))
61 buf->head = offset_to_attr(buf, offset_head);
64 static struct blob_attr *
65 blob_add(struct blob_buf *buf, struct blob_attr *pos, int id, int payload)
67 int offset = attr_to_offset(buf, pos);
68 int required = (offset + sizeof(struct blob_attr) + payload) - buf->buflen;
69 struct blob_attr *attr;
72 blob_buf_grow(buf, required);
73 attr = offset_to_attr(buf, offset);
78 blob_init(attr, id, payload + sizeof(struct blob_attr));
84 blob_buf_init(struct blob_buf *buf, int id)
87 buf->grow = blob_buffer_grow;
90 if (blob_add(buf, buf->buf, id, 0) == NULL)
97 blob_buf_free(struct blob_buf *buf)
105 blob_fill_pad(struct blob_attr *attr)
107 char *buf = (char *) attr;
108 int len = blob_pad_len(attr);
109 int delta = len - blob_raw_len(attr);
112 memset(buf + len - delta, 0, delta);
116 blob_set_raw_len(struct blob_attr *attr, unsigned int len)
118 int id = blob_id(attr);
119 len &= BLOB_ATTR_LEN_MASK;
120 len |= (id << BLOB_ATTR_ID_SHIFT) & BLOB_ATTR_ID_MASK;
121 attr->id_len = cpu_to_be32(len);
125 blob_new(struct blob_buf *buf, int id, int payload)
127 struct blob_attr *attr;
129 attr = blob_add(buf, blob_next(buf->head), id, payload);
133 blob_set_raw_len(buf->head, blob_pad_len(buf->head) + blob_pad_len(attr));
138 blob_put(struct blob_buf *buf, int id, const void *ptr, int len)
140 struct blob_attr *attr;
142 attr = blob_new(buf, id, len);
147 memcpy(blob_data(attr), ptr, len);
152 blob_nest_start(struct blob_buf *buf, int id)
154 unsigned long offset = attr_to_offset(buf, buf->head);
155 buf->head = blob_new(buf, id, 0);
156 return (void *) offset;
160 blob_nest_end(struct blob_buf *buf, void *cookie)
162 struct blob_attr *attr = offset_to_attr(buf, (unsigned long) cookie);
163 blob_set_raw_len(attr, blob_pad_len(attr) + blob_len(buf->head));
167 static const int blob_type_minlen[BLOB_ATTR_LAST] = {
168 [BLOB_ATTR_STRING] = 1,
169 [BLOB_ATTR_INT8] = sizeof(uint8_t),
170 [BLOB_ATTR_INT16] = sizeof(uint16_t),
171 [BLOB_ATTR_INT32] = sizeof(uint32_t),
172 [BLOB_ATTR_INT64] = sizeof(uint64_t),
176 blob_check_type(const void *ptr, int len, int type)
178 const char *data = ptr;
180 if (type >= BLOB_ATTR_LAST)
183 if (type >= BLOB_ATTR_INT8 && type <= BLOB_ATTR_INT64) {
184 if (len != blob_type_minlen[type])
187 if (len < blob_type_minlen[type])
191 if (type == BLOB_ATTR_STRING && data[len - 1] != 0)
198 blob_parse(struct blob_attr *attr, struct blob_attr **data, const struct blob_attr_info *info, int max)
200 struct blob_attr *pos;
204 memset(data, 0, sizeof(struct blob_attr *) * max);
205 blob_for_each_attr(pos, attr, rem) {
206 int id = blob_id(pos);
207 int len = blob_len(pos);
213 int type = info[id].type;
215 if (type < BLOB_ATTR_LAST) {
216 if (!blob_check_type(blob_data(pos), len, type))
220 if (info[id].minlen && len < info[id].minlen)
223 if (info[id].maxlen && len > info[id].maxlen)
226 if (info[id].validate && !info[id].validate(&info[id], attr))
239 blob_attr_equal(const struct blob_attr *a1, const struct blob_attr *a2)
247 if (blob_pad_len(a1) != blob_pad_len(a2))
250 return !memcmp(a1, a2, blob_pad_len(a1));
254 blob_memdup(struct blob_attr *attr)
256 struct blob_attr *ret;
257 int size = blob_pad_len(attr);
263 memcpy(ret, attr, size);