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)
25 int delta = ((minlen / 256) + 1) * 256;
26 new = realloc(buf->buf, buf->buflen + delta);
29 memset(buf->buf + buf->buflen, 0, delta);
36 blob_init(struct blob_attr *attr, int id, unsigned int len)
38 len &= BLOB_ATTR_LEN_MASK;
39 len |= (id << BLOB_ATTR_ID_SHIFT) & BLOB_ATTR_ID_MASK;
40 attr->id_len = cpu_to_be32(len);
43 static inline struct blob_attr *
44 offset_to_attr(struct blob_buf *buf, int offset)
46 void *ptr = (char *)buf->buf + offset - BLOB_COOKIE;
51 attr_to_offset(struct blob_buf *buf, struct blob_attr *attr)
53 return (char *)attr - (char *) buf->buf + BLOB_COOKIE;
57 blob_buf_grow(struct blob_buf *buf, int required)
59 int offset_head = attr_to_offset(buf, buf->head);
61 if (!buf->grow || !buf->grow(buf, required))
64 buf->head = offset_to_attr(buf, offset_head);
68 static struct blob_attr *
69 blob_add(struct blob_buf *buf, struct blob_attr *pos, int id, int payload)
71 int offset = attr_to_offset(buf, pos);
72 int required = (offset - BLOB_COOKIE + sizeof(struct blob_attr) + payload) - buf->buflen;
73 struct blob_attr *attr;
76 if (!blob_buf_grow(buf, required))
78 attr = offset_to_attr(buf, offset);
83 blob_init(attr, id, payload + sizeof(struct blob_attr));
89 blob_buf_init(struct blob_buf *buf, int id)
92 buf->grow = blob_buffer_grow;
95 if (blob_add(buf, buf->buf, id, 0) == NULL)
102 blob_buf_free(struct blob_buf *buf)
110 blob_fill_pad(struct blob_attr *attr)
112 char *buf = (char *) attr;
113 int len = blob_pad_len(attr);
114 int delta = len - blob_raw_len(attr);
117 memset(buf + len - delta, 0, delta);
121 blob_set_raw_len(struct blob_attr *attr, unsigned int len)
123 len &= BLOB_ATTR_LEN_MASK;
124 attr->id_len &= ~cpu_to_be32(BLOB_ATTR_LEN_MASK);
125 attr->id_len |= cpu_to_be32(len);
129 blob_new(struct blob_buf *buf, int id, int payload)
131 struct blob_attr *attr;
133 attr = blob_add(buf, blob_next(buf->head), id, payload);
137 blob_set_raw_len(buf->head, blob_pad_len(buf->head) + blob_pad_len(attr));
142 blob_put_raw(struct blob_buf *buf, const void *ptr, unsigned int len)
144 struct blob_attr *attr;
146 if (len < sizeof(struct blob_attr) || !ptr)
149 attr = blob_add(buf, blob_next(buf->head), 0, len - sizeof(struct blob_attr));
152 blob_set_raw_len(buf->head, blob_pad_len(buf->head) + len);
153 memcpy(attr, ptr, len);
158 blob_put(struct blob_buf *buf, int id, const void *ptr, unsigned int len)
160 struct blob_attr *attr;
162 attr = blob_new(buf, id, len);
167 memcpy(blob_data(attr), ptr, len);
172 blob_nest_start(struct blob_buf *buf, int id)
174 unsigned long offset = attr_to_offset(buf, buf->head);
175 buf->head = blob_new(buf, id, 0);
178 return (void *) offset;
182 blob_nest_end(struct blob_buf *buf, void *cookie)
184 struct blob_attr *attr = offset_to_attr(buf, (unsigned long) cookie);
185 blob_set_raw_len(attr, blob_pad_len(attr) + blob_len(buf->head));
189 static const size_t blob_type_minlen[BLOB_ATTR_LAST] = {
190 [BLOB_ATTR_STRING] = 1,
191 [BLOB_ATTR_INT8] = sizeof(uint8_t),
192 [BLOB_ATTR_INT16] = sizeof(uint16_t),
193 [BLOB_ATTR_INT32] = sizeof(uint32_t),
194 [BLOB_ATTR_INT64] = sizeof(uint64_t),
195 [BLOB_ATTR_DOUBLE] = sizeof(double),
199 blob_check_type(const void *ptr, unsigned int len, int type)
201 const char *data = ptr;
203 if (type >= BLOB_ATTR_LAST)
206 if (type >= BLOB_ATTR_INT8 && type <= BLOB_ATTR_INT64) {
207 if (len != blob_type_minlen[type])
210 if (len < blob_type_minlen[type])
214 if (type == BLOB_ATTR_STRING && data[len - 1] != 0)
221 blob_parse_attr(struct blob_attr *attr, size_t attr_len, struct blob_attr **data, const struct blob_attr_info *info, int max)
228 if (!attr || attr_len < sizeof(struct blob_attr))
235 len = blob_raw_len(attr);
236 if (len > attr_len || len < sizeof(struct blob_attr))
239 data_len = blob_len(attr);
244 int type = info[id].type;
246 if (type < BLOB_ATTR_LAST) {
247 if (!blob_check_type(blob_data(attr), data_len, type))
251 if (info[id].minlen && len < info[id].minlen)
254 if (info[id].maxlen && len > info[id].maxlen)
257 if (info[id].validate && !info[id].validate(&info[id], attr))
269 blob_parse_untrusted(struct blob_attr *attr, size_t attr_len, struct blob_attr **data, const struct blob_attr_info *info, int max)
271 struct blob_attr *pos;
276 if (!attr || attr_len < sizeof(struct blob_attr))
279 len = blob_raw_len(attr);
283 memset(data, 0, sizeof(struct blob_attr *) * max);
284 blob_for_each_attr_len(pos, attr, len, rem) {
285 found += blob_parse_attr(pos, rem, data, info, max);
291 /* use only on trusted input, otherwise consider blob_parse_untrusted */
293 blob_parse(struct blob_attr *attr, struct blob_attr **data, const struct blob_attr_info *info, int max)
295 struct blob_attr *pos;
299 memset(data, 0, sizeof(struct blob_attr *) * max);
300 blob_for_each_attr(pos, attr, rem) {
301 found += blob_parse_attr(pos, rem, data, info, max);
308 blob_attr_equal(const struct blob_attr *a1, const struct blob_attr *a2)
316 if (blob_pad_len(a1) != blob_pad_len(a2))
319 return !memcmp(a1, a2, blob_pad_len(a1));
323 blob_memdup(struct blob_attr *attr)
325 struct blob_attr *ret;
326 int size = blob_pad_len(attr);
332 memcpy(ret, attr, size);