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 "blob.h"
  20
  21 #define BLOBMSG_ALIGN   2
  22 #define BLOBMSG_PADDING(len) (((len) + (1 << BLOBMSG_ALIGN) - 1) & ~((1 << BLOBMSG_ALIGN) - 1))
  23
  24 enum blobmsg_type {
  25         BLOBMSG_TYPE_UNSPEC,
  26         BLOBMSG_TYPE_ARRAY,
  27         BLOBMSG_TYPE_TABLE,
  28         BLOBMSG_TYPE_STRING,
  29         BLOBMSG_TYPE_INT64,
  30         BLOBMSG_TYPE_INT32,
  31         BLOBMSG_TYPE_INT16,
  32         BLOBMSG_TYPE_INT8,
  33         __BLOBMSG_TYPE_LAST,
  34         BLOBMSG_TYPE_LAST = __BLOBMSG_TYPE_LAST - 1,
  35         BLOBMSG_TYPE_BOOL = BLOBMSG_TYPE_INT8,
  36 };
  37
  38 struct blobmsg_hdr {
  39         uint16_t namelen;
  40         uint8_t name[];
  41 } __packed;
  42
  43 struct blobmsg_policy {
  44         const char *name;
  45         enum blobmsg_type type;
  46 };
  47
  48 static inline int blobmsg_hdrlen(int namelen)
  49 {
  50         return BLOBMSG_PADDING(sizeof(struct blobmsg_hdr) + namelen + 1);
  51 }
  52
  53 static inline const char *blobmsg_name(const struct blob_attr *attr)
  54 {
  55         struct blobmsg_hdr *hdr = (struct blobmsg_hdr *) blob_data(attr);
  56         return (const char *) hdr->name;
  57 }
  58
  59 static inline int blobmsg_type(const struct blob_attr *attr)
  60 {
  61         return blob_id(attr);
  62 }
  63
  64 static inline void *blobmsg_data(const struct blob_attr *attr)
  65 {
  66         struct blobmsg_hdr *hdr = (struct blobmsg_hdr *) blob_data(attr);
  67         return (char *) hdr + blobmsg_hdrlen(be16_to_cpu(hdr->namelen));
  68 }
  69
  70 static inline int blobmsg_data_len(const struct blob_attr *attr)
  71 {
  72         uint8_t *start, *end;
  73
  74         start = (uint8_t *) blob_data(attr);
  75         end = (uint8_t *) blobmsg_data(attr);
  76
  77         return blob_len(attr) - (end - start);
  78 }
  79
  80 bool blobmsg_check_attr(const struct blob_attr *attr, bool name);
  81 bool blobmsg_check_attr_list(const struct blob_attr *attr, int type);
  82 int blobmsg_parse(const struct blobmsg_policy *policy, int policy_len,
  83                   struct blob_attr **tb, void *data, int len);
  84 int blobmsg_parse_array(const struct blobmsg_policy *policy, int policy_len,
  85                         struct blob_attr **tb, void *data, int len);
  86
  87 int blobmsg_add_field(struct blob_buf *buf, int type, const char *name,
  88                       const void *data, int len);
  89
  90 static inline int
  91 blobmsg_add_u8(struct blob_buf *buf, const char *name, uint8_t val)
  92 {
  93         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT8, name, &val, 1);
  94 }
  95
  96 static inline int
  97 blobmsg_add_u16(struct blob_buf *buf, const char *name, uint16_t val)
  98 {
  99         val = cpu_to_be16(val);
 100         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT16, name, &val, 2);
 101 }
 102
 103 static inline int
 104 blobmsg_add_u32(struct blob_buf *buf, const char *name, uint32_t val)
 105 {
 106         val = cpu_to_be32(val);
 107         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT32, name, &val, 4);
 108 }
 109
 110 static inline int
 111 blobmsg_add_u64(struct blob_buf *buf, const char *name, uint64_t val)
 112 {
 113         val = cpu_to_be64(val);
 114         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT64, name, &val, 8);
 115 }
 116
 117 static inline int
 118 blobmsg_add_string(struct blob_buf *buf, const char *name, const char *string)
 119 {
 120         return blobmsg_add_field(buf, BLOBMSG_TYPE_STRING, name, string, strlen(string) + 1);
 121 }
 122
 123 static inline int
 124 blobmsg_add_blob(struct blob_buf *buf, struct blob_attr *attr)
 125 {
 126         return blobmsg_add_field(buf, blobmsg_type(attr), blobmsg_name(attr),
 127                                  blobmsg_data(attr), blobmsg_data_len(attr));
 128 }
 129
 130 void *blobmsg_open_nested(struct blob_buf *buf, const char *name, bool array);
 131
 132 static inline void *
 133 blobmsg_open_array(struct blob_buf *buf, const char *name)
 134 {
 135         return blobmsg_open_nested(buf, name, true);
 136 }
 137
 138 static inline void *
 139 blobmsg_open_table(struct blob_buf *buf, const char *name)
 140 {
 141         return blobmsg_open_nested(buf, name, false);
 142 }
 143
 144 static inline void
 145 blobmsg_close_array(struct blob_buf *buf, void *cookie)
 146 {
 147         blob_nest_end(buf, cookie);
 148 }
 149
 150 static inline void
 151 blobmsg_close_table(struct blob_buf *buf, void *cookie)
 152 {
 153         blob_nest_end(buf, cookie);
 154 }
 155
 156 static inline int blobmsg_buf_init(struct blob_buf *buf)
 157 {
 158         return blob_buf_init(buf, BLOBMSG_TYPE_TABLE);
 159 }
 160
 161 static inline uint8_t blobmsg_get_u8(struct blob_attr *attr)
 162 {
 163         return *(uint8_t *) blobmsg_data(attr);
 164 }
 165
 166 static inline bool blobmsg_get_bool(struct blob_attr *attr)
 167 {
 168         return *(uint8_t *) blobmsg_data(attr);
 169 }
 170
 171 static inline uint16_t blobmsg_get_u16(struct blob_attr *attr)
 172 {
 173         return be16_to_cpu(*(uint16_t *) blobmsg_data(attr));
 174 }
 175
 176 static inline uint32_t blobmsg_get_u32(struct blob_attr *attr)
 177 {
 178         return be32_to_cpu(*(uint32_t *) blobmsg_data(attr));
 179 }
 180
 181 static inline uint64_t blobmsg_get_u64(struct blob_attr *attr)
 182 {
 183         uint32_t *ptr = blobmsg_data(attr);
 184         uint64_t tmp = ((uint64_t) be32_to_cpu(ptr[0])) << 32;
 185         tmp |= be32_to_cpu(ptr[1]);
 186         return tmp;
 187 }
 188
 189 static inline char *blobmsg_get_string(struct blob_attr *attr)
 190 {
 191         return blobmsg_data(attr);
 192 }
 193
 194 void *blobmsg_alloc_string_buffer(struct blob_buf *buf, const char *name, int maxlen);
 195 void *blobmsg_realloc_string_buffer(struct blob_buf *buf, int maxlen);
 196 void blobmsg_add_string_buffer(struct blob_buf *buf);
 197
 198 /* blobmsg to json formatting */
 199
 200 #define blobmsg_for_each_attr(pos, attr, rem) \
 201         for (rem = blobmsg_data_len(attr), pos = blobmsg_data(attr); \
 202                  rem > 0 && (blob_pad_len(pos) <= rem) && \
 203                  (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
 204                  rem -= blob_pad_len(pos), pos = blob_next(pos))
 205
 206 #endif