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_LAST,
  35         BLOBMSG_TYPE_LAST = __BLOBMSG_TYPE_LAST - 1,
  36         BLOBMSG_TYPE_BOOL = BLOBMSG_TYPE_INT8,
  37 };
  38
  39 struct blobmsg_hdr {
  40         uint16_t namelen;
  41         uint8_t name[];
  42 } __packed;
  43
  44 struct blobmsg_policy {
  45         const char *name;
  46         enum blobmsg_type type;
  47 };
  48
  49 static inline int blobmsg_hdrlen(int namelen)
  50 {
  51         return BLOBMSG_PADDING(sizeof(struct blobmsg_hdr) + namelen + 1);
  52 }
  53
  54 static inline const char *blobmsg_name(const struct blob_attr *attr)
  55 {
  56         struct blobmsg_hdr *hdr = (struct blobmsg_hdr *) blob_data(attr);
  57         return (const char *) hdr->name;
  58 }
  59
  60 static inline int blobmsg_type(const struct blob_attr *attr)
  61 {
  62         return blob_id(attr);
  63 }
  64
  65 static inline void *blobmsg_data(const struct blob_attr *attr)
  66 {
  67         struct blobmsg_hdr *hdr = (struct blobmsg_hdr *) blob_data(attr);
  68         return (char *) hdr + blobmsg_hdrlen(be16_to_cpu(hdr->namelen));
  69 }
  70
  71 static inline int blobmsg_data_len(const struct blob_attr *attr)
  72 {
  73         uint8_t *start, *end;
  74
  75         start = (uint8_t *) blob_data(attr);
  76         end = (uint8_t *) blobmsg_data(attr);
  77
  78         return blob_len(attr) - (end - start);
  79 }
  80
  81 bool blobmsg_check_attr(const struct blob_attr *attr, bool name);
  82 bool blobmsg_check_attr_list(const struct blob_attr *attr, int type);
  83 int blobmsg_parse(const struct blobmsg_policy *policy, int policy_len,
  84                   struct blob_attr **tb, void *data, int len);
  85 int blobmsg_parse_array(const struct blobmsg_policy *policy, int policy_len,
  86                         struct blob_attr **tb, void *data, int len);
  87
  88 int blobmsg_add_field(struct blob_buf *buf, int type, const char *name,
  89                       const void *data, int len);
  90
  91 static inline int
  92 blobmsg_add_u8(struct blob_buf *buf, const char *name, uint8_t val)
  93 {
  94         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT8, name, &val, 1);
  95 }
  96
  97 static inline int
  98 blobmsg_add_u16(struct blob_buf *buf, const char *name, uint16_t val)
  99 {
 100         val = cpu_to_be16(val);
 101         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT16, name, &val, 2);
 102 }
 103
 104 static inline int
 105 blobmsg_add_u32(struct blob_buf *buf, const char *name, uint32_t val)
 106 {
 107         val = cpu_to_be32(val);
 108         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT32, name, &val, 4);
 109 }
 110
 111 static inline int
 112 blobmsg_add_u64(struct blob_buf *buf, const char *name, uint64_t val)
 113 {
 114         val = cpu_to_be64(val);
 115         return blobmsg_add_field(buf, BLOBMSG_TYPE_INT64, name, &val, 8);
 116 }
 117
 118 static inline int
 119 blobmsg_add_string(struct blob_buf *buf, const char *name, const char *string)
 120 {
 121         return blobmsg_add_field(buf, BLOBMSG_TYPE_STRING, name, string, strlen(string) + 1);
 122 }
 123
 124 static inline int
 125 blobmsg_add_blob(struct blob_buf *buf, struct blob_attr *attr)
 126 {
 127         return blobmsg_add_field(buf, blobmsg_type(attr), blobmsg_name(attr),
 128                                  blobmsg_data(attr), blobmsg_data_len(attr));
 129 }
 130
 131 void *blobmsg_open_nested(struct blob_buf *buf, const char *name, bool array);
 132
 133 static inline void *
 134 blobmsg_open_array(struct blob_buf *buf, const char *name)
 135 {
 136         return blobmsg_open_nested(buf, name, true);
 137 }
 138
 139 static inline void *
 140 blobmsg_open_table(struct blob_buf *buf, const char *name)
 141 {
 142         return blobmsg_open_nested(buf, name, false);
 143 }
 144
 145 static inline void
 146 blobmsg_close_array(struct blob_buf *buf, void *cookie)
 147 {
 148         blob_nest_end(buf, cookie);
 149 }
 150
 151 static inline void
 152 blobmsg_close_table(struct blob_buf *buf, void *cookie)
 153 {
 154         blob_nest_end(buf, cookie);
 155 }
 156
 157 static inline int blobmsg_buf_init(struct blob_buf *buf)
 158 {
 159         return blob_buf_init(buf, BLOBMSG_TYPE_TABLE);
 160 }
 161
 162 static inline uint8_t blobmsg_get_u8(struct blob_attr *attr)
 163 {
 164         return *(uint8_t *) blobmsg_data(attr);
 165 }
 166
 167 static inline bool blobmsg_get_bool(struct blob_attr *attr)
 168 {
 169         return *(uint8_t *) blobmsg_data(attr);
 170 }
 171
 172 static inline uint16_t blobmsg_get_u16(struct blob_attr *attr)
 173 {
 174         return be16_to_cpu(*(uint16_t *) blobmsg_data(attr));
 175 }
 176
 177 static inline uint32_t blobmsg_get_u32(struct blob_attr *attr)
 178 {
 179         return be32_to_cpu(*(uint32_t *) blobmsg_data(attr));
 180 }
 181
 182 static inline uint64_t blobmsg_get_u64(struct blob_attr *attr)
 183 {
 184         uint32_t *ptr = blobmsg_data(attr);
 185         uint64_t tmp = ((uint64_t) be32_to_cpu(ptr[0])) << 32;
 186         tmp |= be32_to_cpu(ptr[1]);
 187         return tmp;
 188 }
 189
 190 static inline char *blobmsg_get_string(struct blob_attr *attr)
 191 {
 192         return blobmsg_data(attr);
 193 }
 194
 195 void *blobmsg_alloc_string_buffer(struct blob_buf *buf, const char *name, int maxlen);
 196 void *blobmsg_realloc_string_buffer(struct blob_buf *buf, int maxlen);
 197 void blobmsg_add_string_buffer(struct blob_buf *buf);
 198
 199 void blobmsg_vprintf(struct blob_buf *buf, const char *name, const char *format, va_list arg);
 200 void blobmsg_printf(struct blob_buf *buf, const char *name, const char *format, ...)
 201      __attribute__((format(printf, 3, 4)));
 202
 203
 204 /* blobmsg to json formatting */
 205
 206 #define blobmsg_for_each_attr(pos, attr, rem) \
 207         for (rem = attr ? blobmsg_data_len(attr) : 0, \
 208              pos = attr ? blobmsg_data(attr) : 0; \
 209              rem > 0 && (blob_pad_len(pos) <= rem) && \
 210              (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
 211              rem -= blob_pad_len(pos), pos = blob_next(pos))
 212
 213 #endif