blobmsg.h

   1 /*
   2  * blobmsg - library for generating/parsing structured blob messages
   3  *
   4  * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU Lesser General Public License version 2.1
   8  * as published by the Free Software Foundation
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  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 = blob_data(attr);
  56         return (const char *) hdr->name;
  57 }
  58
  59 static inline void *blobmsg_data(const struct blob_attr *attr)
  60 {
  61         struct blobmsg_hdr *hdr = blob_data(attr);
  62         return (char *) hdr + blobmsg_hdrlen(hdr->namelen);
  63 }
  64
  65 static inline int blobmsg_data_len(const struct blob_attr *attr)
  66 {
  67         uint8_t *start, *end;
  68
  69         start = blob_data(attr);
  70         end = blobmsg_data(attr);
  71
  72         return blob_len(attr) - (end - start);
  73 }
  74
  75 bool blobmsg_check_attr(const struct blob_attr *attr, bool name);
  76 int blobmsg_parse(const struct blobmsg_policy *policy, int policy_len,
  77                   struct blob_attr **tb, void *data, int len);
  78
  79 int blobmsg_add_field(struct blob_buf *buf, int type, const char *name,
  80                       const void *data, int len);
  81
  82 static inline int
  83 blobmsg_add_u8(struct blob_buf *buf, const char *name, uint8_t val)
  84 {
  85         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT8, name, &val, 1);
  86 }
  87
  88 static inline int
  89 blobmsg_add_u16(struct blob_buf *buf, const char *name, uint16_t val)
  90 {
  91         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT16, name, &val, 2);
  92 }
  93
  94 static inline int
  95 blobmsg_add_u32(struct blob_buf *buf, const char *name, uint32_t val)
  96 {
  97         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT32, name, &val, 4);
  98 }
  99
 100 static inline int
 101 blobmsg_add_u64(struct blob_buf *buf, const char *name, uint64_t val)
 102 {
 103         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT64, name, &val, 8);
 104 }
 105
 106 static inline int
 107 blobmsg_add_string(struct blob_buf *buf, const char *name, const char *string)
 108 {
 109         return blobmsg_add_field(buf, BLOBMSG_TYPE_STRING, name, string, strlen(string) + 1);
 110 }
 111
 112 void *blobmsg_open_nested(struct blob_buf *buf, const char *name, bool array);
 113
 114 static inline void *
 115 blobmsg_open_array(struct blob_buf *buf, const char *name)
 116 {
 117         return blobmsg_open_nested(buf, name, true);
 118 }
 119
 120 static inline void *
 121 blobmsg_open_table(struct blob_buf *buf, const char *name)
 122 {
 123         return blobmsg_open_nested(buf, name, false);
 124 }
 125
 126 static inline void
 127 blobmsg_close_array(struct blob_buf *buf, void *cookie)
 128 {
 129         blob_nest_end(buf, cookie);
 130 }
 131
 132 static inline void
 133 blobmsg_close_table(struct blob_buf *buf, void *cookie)
 134 {
 135         blob_nest_end(buf, cookie);
 136 }
 137
 138 static inline int blobmsg_buf_init(struct blob_buf *buf)
 139 {
 140         return blob_buf_init(buf, BLOBMSG_TYPE_TABLE);
 141 }
 142
 143 static inline uint8_t blobmsg_get_u8(struct blob_attr *attr)
 144 {
 145         return *(uint8_t *) blobmsg_data(attr);
 146 }
 147
 148 static inline bool blobmsg_get_bool(struct blob_attr *attr)
 149 {
 150         return *(uint8_t *) blobmsg_data(attr);
 151 }
 152
 153 static inline uint16_t blobmsg_get_u16(struct blob_attr *attr)
 154 {
 155         return *(uint16_t *) blobmsg_data(attr);
 156 }
 157
 158 static inline uint32_t blobmsg_get_u32(struct blob_attr *attr)
 159 {
 160         return *(uint32_t *) blobmsg_data(attr);
 161 }
 162
 163 static inline uint64_t blobmsg_get_u64(struct blob_attr *attr)
 164 {
 165         return *(uint64_t *) blobmsg_data(attr);
 166 }
 167
 168 void *blobmsg_alloc_string_buffer(struct blob_buf *buf, const char *name, int maxlen);
 169 void blobmsg_add_string_buffer(struct blob_buf *buf);
 170
 171 /* blobmsg to json formatting */
 172
 173 #define blobmsg_for_each_attr(pos, attr, rem) \
 174         for (rem = blobmsg_data_len(attr), pos = blobmsg_data(attr); \
 175                  (blob_pad_len(pos) <= rem) && \
 176                  (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
 177                  rem -= blob_pad_len(pos), pos = blob_next(pos))
 178
 179 #endif