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 };
  39
  40 struct blobmsg_hdr {
  41         uint16_t namelen;
  42         uint8_t name[];
  43 } __packed;
  44
  45 struct blobmsg_policy {
  46         const char *name;
  47         enum blobmsg_type type;
  48 };
  49
  50 static inline int blobmsg_hdrlen(unsigned int namelen)
  51 {
  52         return BLOBMSG_PADDING(sizeof(struct blobmsg_hdr) + namelen + 1);
  53 }
  54
  55 static inline void blobmsg_clear_name(struct blob_attr *attr)
  56 {
  57         struct blobmsg_hdr *hdr = (struct blobmsg_hdr *) blob_data(attr);
  58         hdr->name[0] = 0;
  59 }
  60
  61 static inline const char *blobmsg_name(const struct blob_attr *attr)
  62 {
  63         struct blobmsg_hdr *hdr = (struct blobmsg_hdr *) blob_data(attr);
  64         return (const char *) hdr->name;
  65 }
  66
  67 static inline int blobmsg_type(const struct blob_attr *attr)
  68 {
  69         return blob_id(attr);
  70 }
  71
  72 static inline void *blobmsg_data(const struct blob_attr *attr)
  73 {
  74         struct blobmsg_hdr *hdr;
  75         char *data;
  76
  77         if (!attr)
  78                 return NULL;
  79
  80         hdr = (struct blobmsg_hdr *) blob_data(attr);
  81         data = (char *) blob_data(attr);
  82
  83         if (blob_is_extended(attr))
  84                 data += blobmsg_hdrlen(be16_to_cpu(hdr->namelen));
  85
  86         return data;
  87 }
  88
  89 static inline size_t blobmsg_data_len(const struct blob_attr *attr)
  90 {
  91         uint8_t *start, *end;
  92
  93         if (!attr)
  94                 return 0;
  95
  96         start = (uint8_t *) blob_data(attr);
  97         end = (uint8_t *) blobmsg_data(attr);
  98
  99         return blob_len(attr) - (end - start);
 100 }
 101
 102 static inline size_t blobmsg_len(const struct blob_attr *attr)
 103 {
 104         return blobmsg_data_len(attr);
 105 }
 106
 107 bool blobmsg_check_attr(const struct blob_attr *attr, bool name);
 108 bool blobmsg_check_attr_list(const struct blob_attr *attr, int type);
 109
 110 bool blobmsg_check_attr_len(const struct blob_attr *attr, bool name, size_t len);
 111
 112 /*
 113  * blobmsg_check_array: validate array/table and return size
 114  *
 115  * Checks if all elements of an array or table are valid and have
 116  * the specified type. Returns the number of elements in the array
 117  */
 118 int blobmsg_check_array(const struct blob_attr *attr, int type);
 119
 120 int blobmsg_parse(const struct blobmsg_policy *policy, int policy_len,
 121                   struct blob_attr **tb, void *data, unsigned int len);
 122 int blobmsg_parse_array(const struct blobmsg_policy *policy, int policy_len,
 123                         struct blob_attr **tb, void *data, unsigned int len);
 124
 125 int blobmsg_add_field(struct blob_buf *buf, int type, const char *name,
 126                       const void *data, unsigned int len);
 127
 128 static inline int
 129 blobmsg_add_double(struct blob_buf *buf, const char *name, double val)
 130 {
 131         union {
 132                 double d;
 133                 uint64_t u64;
 134         } v;
 135         v.d = val;
 136         v.u64 = cpu_to_be64(v.u64);
 137         return blobmsg_add_field(buf, BLOBMSG_TYPE_DOUBLE, name, &v.u64, 8);
 138 }
 139
 140 static inline int
 141 blobmsg_add_u8(struct blob_buf *buf, const char *name, uint8_t val)
 142 {
 143         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT8, name, &val, 1);
 144 }
 145
 146 static inline int
 147 blobmsg_add_u16(struct blob_buf *buf, const char *name, uint16_t val)
 148 {
 149         val = cpu_to_be16(val);
 150         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT16, name, &val, 2);
 151 }
 152
 153 static inline int
 154 blobmsg_add_u32(struct blob_buf *buf, const char *name, uint32_t val)
 155 {
 156         val = cpu_to_be32(val);
 157         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT32, name, &val, 4);
 158 }
 159
 160 static inline int
 161 blobmsg_add_u64(struct blob_buf *buf, const char *name, uint64_t val)
 162 {
 163         val = cpu_to_be64(val);
 164         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT64, name, &val, 8);
 165 }
 166
 167 static inline int
 168 blobmsg_add_string(struct blob_buf *buf, const char *name, const char *string)
 169 {
 170         return blobmsg_add_field(buf, BLOBMSG_TYPE_STRING, name, string, strlen(string) + 1);
 171 }
 172
 173 static inline int
 174 blobmsg_add_blob(struct blob_buf *buf, struct blob_attr *attr)
 175 {
 176         return blobmsg_add_field(buf, blobmsg_type(attr), blobmsg_name(attr),
 177                                  blobmsg_data(attr), blobmsg_data_len(attr));
 178 }
 179
 180 void *blobmsg_open_nested(struct blob_buf *buf, const char *name, bool array);
 181
 182 static inline void *
 183 blobmsg_open_array(struct blob_buf *buf, const char *name)
 184 {
 185         return blobmsg_open_nested(buf, name, true);
 186 }
 187
 188 static inline void *
 189 blobmsg_open_table(struct blob_buf *buf, const char *name)
 190 {
 191         return blobmsg_open_nested(buf, name, false);
 192 }
 193
 194 static inline void
 195 blobmsg_close_array(struct blob_buf *buf, void *cookie)
 196 {
 197         blob_nest_end(buf, cookie);
 198 }
 199
 200 static inline void
 201 blobmsg_close_table(struct blob_buf *buf, void *cookie)
 202 {
 203         blob_nest_end(buf, cookie);
 204 }
 205
 206 static inline int blobmsg_buf_init(struct blob_buf *buf)
 207 {
 208         return blob_buf_init(buf, BLOBMSG_TYPE_TABLE);
 209 }
 210
 211 static inline uint8_t blobmsg_get_u8(struct blob_attr *attr)
 212 {
 213         return *(uint8_t *) blobmsg_data(attr);
 214 }
 215
 216 static inline bool blobmsg_get_bool(struct blob_attr *attr)
 217 {
 218         return *(uint8_t *) blobmsg_data(attr);
 219 }
 220
 221 static inline uint16_t blobmsg_get_u16(struct blob_attr *attr)
 222 {
 223         return be16_to_cpu(*(uint16_t *) blobmsg_data(attr));
 224 }
 225
 226 static inline uint32_t blobmsg_get_u32(struct blob_attr *attr)
 227 {
 228         return be32_to_cpu(*(uint32_t *) blobmsg_data(attr));
 229 }
 230
 231 static inline uint64_t blobmsg_get_u64(struct blob_attr *attr)
 232 {
 233         uint32_t *ptr = (uint32_t *) blobmsg_data(attr);
 234         uint64_t tmp = ((uint64_t) be32_to_cpu(ptr[0])) << 32;
 235         tmp |= be32_to_cpu(ptr[1]);
 236         return tmp;
 237 }
 238
 239 static inline double blobmsg_get_double(struct blob_attr *attr)
 240 {
 241         union {
 242                 double d;
 243                 uint64_t u64;
 244         } v;
 245         v.u64 = blobmsg_get_u64(attr);
 246         return v.d;
 247 }
 248
 249 static inline char *blobmsg_get_string(struct blob_attr *attr)
 250 {
 251         if (!attr)
 252                 return NULL;
 253
 254         return (char *) blobmsg_data(attr);
 255 }
 256
 257 void *blobmsg_alloc_string_buffer(struct blob_buf *buf, const char *name, unsigned int maxlen);
 258 void *blobmsg_realloc_string_buffer(struct blob_buf *buf, unsigned int maxlen);
 259 void blobmsg_add_string_buffer(struct blob_buf *buf);
 260
 261 int blobmsg_vprintf(struct blob_buf *buf, const char *name, const char *format, va_list arg);
 262 int blobmsg_printf(struct blob_buf *buf, const char *name, const char *format, ...)
 263      __attribute__((format(printf, 3, 4)));
 264
 265
 266 /* blobmsg to json formatting */
 267
 268 #define blobmsg_for_each_attr(pos, attr, rem) \
 269         for (rem = attr ? blobmsg_data_len(attr) : 0, \
 270              pos = (struct blob_attr *) (attr ? blobmsg_data(attr) : NULL); \
 271              rem >= sizeof(struct blob_attr) && (blob_pad_len(pos) <= rem) && \
 272              (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
 273              rem -= blob_pad_len(pos), pos = blob_next(pos))
 274
 275 #endif