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