4a151c717284a4821fdb92b35665fca80ac7d102
[project/libubox.git] / blobmsg.h
1 /*
2 * Copyright (C) 2010-2012 Felix Fietkau <nbd@openwrt.org>
3 *
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16 #ifndef __BLOBMSG_H
17 #define __BLOBMSG_H
18
19 #include <stdarg.h>
20 #include "blob.h"
21
22 #define BLOBMSG_ALIGN 2
23 #define BLOBMSG_PADDING(len) (((len) + (1 << BLOBMSG_ALIGN) - 1) & ~((1 << BLOBMSG_ALIGN) - 1))
24
25 enum blobmsg_type {
26 BLOBMSG_TYPE_UNSPEC,
27 BLOBMSG_TYPE_ARRAY,
28 BLOBMSG_TYPE_TABLE,
29 BLOBMSG_TYPE_STRING,
30 BLOBMSG_TYPE_INT64,
31 BLOBMSG_TYPE_INT32,
32 BLOBMSG_TYPE_INT16,
33 BLOBMSG_TYPE_INT8,
34 BLOBMSG_TYPE_DOUBLE,
35 __BLOBMSG_TYPE_LAST,
36 BLOBMSG_TYPE_LAST = __BLOBMSG_TYPE_LAST - 1,
37 BLOBMSG_TYPE_BOOL = BLOBMSG_TYPE_INT8,
38 BLOBMSG_CAST_INT64,
39 };
40
41 struct blobmsg_hdr {
42 uint16_t namelen;
43 uint8_t name[];
44 } __packed;
45
46 struct blobmsg_policy {
47 const char *name;
48 enum blobmsg_type type;
49 };
50
51 static inline int blobmsg_hdrlen(unsigned int namelen)
52 {
53 return BLOBMSG_PADDING(sizeof(struct blobmsg_hdr) + namelen + 1);
54 }
55
56 static inline void blobmsg_clear_name(struct blob_attr *attr)
57 {
58 struct blobmsg_hdr *hdr = (struct blobmsg_hdr *) blob_data(attr);
59 hdr->name[0] = 0;
60 }
61
62 static inline const char *blobmsg_name(const struct blob_attr *attr)
63 {
64 struct blobmsg_hdr *hdr = (struct blobmsg_hdr *) blob_data(attr);
65 return (const char *) hdr->name;
66 }
67
68 static inline int blobmsg_type(const struct blob_attr *attr)
69 {
70 return blob_id(attr);
71 }
72
73 static uint16_t blobmsg_namelen(const struct blobmsg_hdr *hdr)
74 {
75 return be16_to_cpu(hdr->namelen);
76 }
77
78 static inline void *blobmsg_data(const struct blob_attr *attr)
79 {
80 struct blobmsg_hdr *hdr;
81 char *data;
82
83 if (!attr)
84 return NULL;
85
86 hdr = (struct blobmsg_hdr *) blob_data(attr);
87 data = (char *) blob_data(attr);
88
89 if (blob_is_extended(attr))
90 data += blobmsg_hdrlen(blobmsg_namelen(hdr));
91
92 return data;
93 }
94
95 static inline size_t blobmsg_data_len(const struct blob_attr *attr)
96 {
97 uint8_t *start, *end;
98
99 if (!attr)
100 return 0;
101
102 start = (uint8_t *) blob_data(attr);
103 end = (uint8_t *) blobmsg_data(attr);
104
105 return blob_len(attr) - (end - start);
106 }
107
108 static inline size_t blobmsg_len(const struct blob_attr *attr)
109 {
110 return blobmsg_data_len(attr);
111 }
112
113 /*
114 * blobmsg_check_attr: validate a list of attributes
115 *
116 * This method may be used with trusted data only. Providing
117 * malformed blobs will cause out of bounds memory access.
118 */
119 bool blobmsg_check_attr(const struct blob_attr *attr, bool name);
120
121 /*
122 * blobmsg_check_attr_len: validate a list of attributes
123 *
124 * This method should be safer implementation of blobmsg_check_attr.
125 * It will limit all memory access performed on the blob to the
126 * range [attr, attr + len] (upper bound non inclusive) and is
127 * thus suited for checking of untrusted blob attributes.
128 */
129 bool blobmsg_check_attr_len(const struct blob_attr *attr, bool name, size_t len);
130
131 /*
132 * blobmsg_check_attr_list: validate a list of attributes
133 *
134 * This method may be used with trusted data only. Providing
135 * malformed blobs will cause out of bounds memory access.
136 */
137 bool blobmsg_check_attr_list(const struct blob_attr *attr, int type);
138
139 /*
140 * blobmsg_check_attr_list_len: validate a list of untrusted attributes
141 *
142 * This method should be safer implementation of blobmsg_check_attr_list.
143 * It will limit all memory access performed on the blob to the
144 * range [attr, attr + len] (upper bound non inclusive) and is
145 * thus suited for checking of untrusted blob attributes.
146 */
147 bool blobmsg_check_attr_list_len(const struct blob_attr *attr, int type, size_t len);
148
149 /*
150 * blobmsg_check_array: validate array/table and return size
151 *
152 * Checks if all elements of an array or table are valid and have
153 * the specified type. Returns the number of elements in the array
154 *
155 * This method may be used with trusted data only. Providing
156 * malformed blobs will cause out of bounds memory access.
157 */
158 int blobmsg_check_array(const struct blob_attr *attr, int type);
159
160 /*
161 * blobmsg_check_array_len: validate untrusted array/table and return size
162 *
163 * Checks if all elements of an array or table are valid and have
164 * the specified type. Returns the number of elements in the array.
165 *
166 * This method should be safer implementation of blobmsg_check_array.
167 * It will limit all memory access performed on the blob to the
168 * range [attr, attr + len] (upper bound non inclusive) and is
169 * thus suited for checking of untrusted blob attributes.
170 */
171 int blobmsg_check_array_len(const struct blob_attr *attr, int type, size_t len);
172
173 int blobmsg_parse(const struct blobmsg_policy *policy, int policy_len,
174 struct blob_attr **tb, void *data, unsigned int len);
175 int blobmsg_parse_array(const struct blobmsg_policy *policy, int policy_len,
176 struct blob_attr **tb, void *data, unsigned int len);
177
178 int blobmsg_add_field(struct blob_buf *buf, int type, const char *name,
179 const void *data, unsigned int len);
180
181 static inline int
182 blobmsg_add_double(struct blob_buf *buf, const char *name, double val)
183 {
184 union {
185 double d;
186 uint64_t u64;
187 } v;
188 v.d = val;
189 v.u64 = cpu_to_be64(v.u64);
190 return blobmsg_add_field(buf, BLOBMSG_TYPE_DOUBLE, name, &v.u64, 8);
191 }
192
193 static inline int
194 blobmsg_add_u8(struct blob_buf *buf, const char *name, uint8_t val)
195 {
196 return blobmsg_add_field(buf, BLOBMSG_TYPE_INT8, name, &val, 1);
197 }
198
199 static inline int
200 blobmsg_add_u16(struct blob_buf *buf, const char *name, uint16_t val)
201 {
202 val = cpu_to_be16(val);
203 return blobmsg_add_field(buf, BLOBMSG_TYPE_INT16, name, &val, 2);
204 }
205
206 static inline int
207 blobmsg_add_u32(struct blob_buf *buf, const char *name, uint32_t val)
208 {
209 val = cpu_to_be32(val);
210 return blobmsg_add_field(buf, BLOBMSG_TYPE_INT32, name, &val, 4);
211 }
212
213 static inline int
214 blobmsg_add_u64(struct blob_buf *buf, const char *name, uint64_t val)
215 {
216 val = cpu_to_be64(val);
217 return blobmsg_add_field(buf, BLOBMSG_TYPE_INT64, name, &val, 8);
218 }
219
220 static inline int
221 blobmsg_add_string(struct blob_buf *buf, const char *name, const char *string)
222 {
223 return blobmsg_add_field(buf, BLOBMSG_TYPE_STRING, name, string, strlen(string) + 1);
224 }
225
226 static inline int
227 blobmsg_add_blob(struct blob_buf *buf, struct blob_attr *attr)
228 {
229 return blobmsg_add_field(buf, blobmsg_type(attr), blobmsg_name(attr),
230 blobmsg_data(attr), blobmsg_data_len(attr));
231 }
232
233 void *blobmsg_open_nested(struct blob_buf *buf, const char *name, bool array);
234
235 static inline void *
236 blobmsg_open_array(struct blob_buf *buf, const char *name)
237 {
238 return blobmsg_open_nested(buf, name, true);
239 }
240
241 static inline void *
242 blobmsg_open_table(struct blob_buf *buf, const char *name)
243 {
244 return blobmsg_open_nested(buf, name, false);
245 }
246
247 static inline void
248 blobmsg_close_array(struct blob_buf *buf, void *cookie)
249 {
250 blob_nest_end(buf, cookie);
251 }
252
253 static inline void
254 blobmsg_close_table(struct blob_buf *buf, void *cookie)
255 {
256 blob_nest_end(buf, cookie);
257 }
258
259 static inline int blobmsg_buf_init(struct blob_buf *buf)
260 {
261 return blob_buf_init(buf, BLOBMSG_TYPE_TABLE);
262 }
263
264 static inline uint8_t blobmsg_get_u8(struct blob_attr *attr)
265 {
266 return *(uint8_t *) blobmsg_data(attr);
267 }
268
269 static inline bool blobmsg_get_bool(struct blob_attr *attr)
270 {
271 return *(uint8_t *) blobmsg_data(attr);
272 }
273
274 static inline uint16_t blobmsg_get_u16(struct blob_attr *attr)
275 {
276 return be16_to_cpu(*(uint16_t *) blobmsg_data(attr));
277 }
278
279 static inline uint32_t blobmsg_get_u32(struct blob_attr *attr)
280 {
281 return be32_to_cpu(*(uint32_t *) blobmsg_data(attr));
282 }
283
284 static inline uint64_t blobmsg_get_u64(struct blob_attr *attr)
285 {
286 uint32_t *ptr = (uint32_t *) blobmsg_data(attr);
287 uint64_t tmp = ((uint64_t) be32_to_cpu(ptr[0])) << 32;
288 tmp |= be32_to_cpu(ptr[1]);
289 return tmp;
290 }
291
292 static inline uint64_t blobmsg_cast_u64(struct blob_attr *attr)
293 {
294 uint64_t tmp = 0;
295
296 if (blobmsg_type(attr) == BLOBMSG_TYPE_INT64)
297 tmp = blobmsg_get_u64(attr);
298 else if (blobmsg_type(attr) == BLOBMSG_TYPE_INT32)
299 tmp = blobmsg_get_u32(attr);
300 else if (blobmsg_type(attr) == BLOBMSG_TYPE_INT16)
301 tmp = blobmsg_get_u16(attr);
302 else if (blobmsg_type(attr) == BLOBMSG_TYPE_INT8)
303 tmp = blobmsg_get_u8(attr);
304
305 return tmp;
306 }
307
308 static inline int64_t blobmsg_cast_s64(struct blob_attr *attr)
309 {
310 int64_t tmp = 0;
311
312 if (blobmsg_type(attr) == BLOBMSG_TYPE_INT64)
313 tmp = blobmsg_get_u64(attr);
314 else if (blobmsg_type(attr) == BLOBMSG_TYPE_INT32)
315 tmp = (int32_t)blobmsg_get_u32(attr);
316 else if (blobmsg_type(attr) == BLOBMSG_TYPE_INT16)
317 tmp = (int16_t)blobmsg_get_u16(attr);
318 else if (blobmsg_type(attr) == BLOBMSG_TYPE_INT8)
319 tmp = (int8_t)blobmsg_get_u8(attr);
320
321 return tmp;
322 }
323
324 static inline double blobmsg_get_double(struct blob_attr *attr)
325 {
326 union {
327 double d;
328 uint64_t u64;
329 } v;
330 v.u64 = blobmsg_get_u64(attr);
331 return v.d;
332 }
333
334 static inline char *blobmsg_get_string(struct blob_attr *attr)
335 {
336 if (!attr)
337 return NULL;
338
339 return (char *) blobmsg_data(attr);
340 }
341
342 void *blobmsg_alloc_string_buffer(struct blob_buf *buf, const char *name, unsigned int maxlen);
343 void *blobmsg_realloc_string_buffer(struct blob_buf *buf, unsigned int maxlen);
344 void blobmsg_add_string_buffer(struct blob_buf *buf);
345
346 int blobmsg_vprintf(struct blob_buf *buf, const char *name, const char *format, va_list arg);
347 int blobmsg_printf(struct blob_buf *buf, const char *name, const char *format, ...)
348 __attribute__((format(printf, 3, 4)));
349
350 #define blobmsg_for_each_attr(pos, attr, rem) \
351 for (rem = attr ? blobmsg_data_len(attr) : 0, \
352 pos = (struct blob_attr *) (attr ? blobmsg_data(attr) : NULL); \
353 rem >= sizeof(struct blob_attr) && (blob_pad_len(pos) <= rem) && \
354 (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
355 rem -= blob_pad_len(pos), pos = blob_next(pos))
356
357 #define __blobmsg_for_each_attr(pos, attr, rem) \
358 for (pos = (struct blob_attr *) (attr ? blobmsg_data(attr) : NULL); \
359 rem >= sizeof(struct blob_attr) && (blob_pad_len(pos) <= rem) && \
360 (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
361 rem -= blob_pad_len(pos), pos = blob_next(pos))
362
363 #endif