blob.h

   1 /*
   2  * blob - library for generating/parsing tagged binary data
   3  *
   4  * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #ifndef _BLOB_H__
  20 #define _BLOB_H__
  21
  22 #include <stdbool.h>
  23 #include <stdlib.h>
  24 #include <stdint.h>
  25 #include <string.h>
  26 #include <stdio.h>
  27 #include <errno.h>
  28
  29 #include "utils.h"
  30
  31 #define BLOB_COOKIE             0x01234567
  32
  33 enum {
  34         BLOB_ATTR_UNSPEC,
  35         BLOB_ATTR_NESTED,
  36         BLOB_ATTR_BINARY,
  37         BLOB_ATTR_STRING,
  38         BLOB_ATTR_INT8,
  39         BLOB_ATTR_INT16,
  40         BLOB_ATTR_INT32,
  41         BLOB_ATTR_INT64,
  42         BLOB_ATTR_DOUBLE,
  43         BLOB_ATTR_LAST
  44 };
  45
  46 #define BLOB_ATTR_ID_MASK  0x7f000000
  47 #define BLOB_ATTR_ID_SHIFT 24
  48 #define BLOB_ATTR_LEN_MASK 0x00ffffff
  49 #define BLOB_ATTR_ALIGN    4
  50 #define BLOB_ATTR_EXTENDED 0x80000000
  51
  52 struct blob_attr {
  53         uint32_t id_len;
  54         char data[];
  55 } __packed;
  56
  57 struct blob_attr_info {
  58         unsigned int type;
  59         unsigned int minlen;
  60         unsigned int maxlen;
  61         bool (*validate)(const struct blob_attr_info *, struct blob_attr *);
  62 };
  63
  64 struct blob_buf {
  65         struct blob_attr *head;
  66         bool (*grow)(struct blob_buf *buf, int minlen);
  67         int buflen;
  68         void *buf;
  69 };
  70
  71 /*
  72  * blob_data: returns the data pointer for an attribute
  73  */
  74 static inline void *
  75 blob_data(const struct blob_attr *attr)
  76 {
  77         return (void *) attr->data;
  78 }
  79
  80 /*
  81  * blob_id: returns the id of an attribute
  82  */
  83 static inline unsigned int
  84 blob_id(const struct blob_attr *attr)
  85 {
  86         int id = (be32_to_cpu(attr->id_len) & BLOB_ATTR_ID_MASK) >> BLOB_ATTR_ID_SHIFT;
  87         return id;
  88 }
  89
  90 static inline bool
  91 blob_is_extended(const struct blob_attr *attr)
  92 {
  93         return !!(attr->id_len & cpu_to_be32(BLOB_ATTR_EXTENDED));
  94 }
  95
  96 /*
  97  * blob_len: returns the length of the attribute's payload
  98  */
  99 static inline unsigned int
 100 blob_len(const struct blob_attr *attr)
 101 {
 102         return (be32_to_cpu(attr->id_len) & BLOB_ATTR_LEN_MASK) - sizeof(struct blob_attr);
 103 }
 104
 105 /*
 106  * blob_raw_len: returns the complete length of an attribute (including the header)
 107  */
 108 static inline unsigned int
 109 blob_raw_len(const struct blob_attr *attr)
 110 {
 111         return blob_len(attr) + sizeof(struct blob_attr);
 112 }
 113
 114 /*
 115  * blob_pad_len: returns the padded length of an attribute (including the header)
 116  */
 117 static inline unsigned int
 118 blob_pad_len(const struct blob_attr *attr)
 119 {
 120         unsigned int len = blob_raw_len(attr);
 121         len = (len + BLOB_ATTR_ALIGN - 1) & ~(BLOB_ATTR_ALIGN - 1);
 122         return len;
 123 }
 124
 125 static inline uint8_t
 126 blob_get_u8(const struct blob_attr *attr)
 127 {
 128         return *((uint8_t *) attr->data);
 129 }
 130
 131 static inline uint16_t
 132 blob_get_u16(const struct blob_attr *attr)
 133 {
 134         uint16_t *tmp = (uint16_t*)attr->data;
 135         return be16_to_cpu(*tmp);
 136 }
 137
 138 static inline uint32_t
 139 blob_get_u32(const struct blob_attr *attr)
 140 {
 141         uint32_t *tmp = (uint32_t*)attr->data;
 142         return be32_to_cpu(*tmp);
 143 }
 144
 145 static inline uint64_t
 146 blob_get_u64(const struct blob_attr *attr)
 147 {
 148         uint32_t *ptr = (uint32_t *) blob_data(attr);
 149         uint64_t tmp = ((uint64_t) be32_to_cpu(ptr[0])) << 32;
 150         tmp |= be32_to_cpu(ptr[1]);
 151         return tmp;
 152 }
 153
 154 static inline int8_t
 155 blob_get_int8(const struct blob_attr *attr)
 156 {
 157         return blob_get_u8(attr);
 158 }
 159
 160 static inline int16_t
 161 blob_get_int16(const struct blob_attr *attr)
 162 {
 163         return blob_get_u16(attr);
 164 }
 165
 166 static inline int32_t
 167 blob_get_int32(const struct blob_attr *attr)
 168 {
 169         return blob_get_u32(attr);
 170 }
 171
 172 static inline int64_t
 173 blob_get_int64(const struct blob_attr *attr)
 174 {
 175         return blob_get_u64(attr);
 176 }
 177
 178 static inline const char *
 179 blob_get_string(const struct blob_attr *attr)
 180 {
 181         return attr->data;
 182 }
 183
 184 static inline struct blob_attr *
 185 blob_next(const struct blob_attr *attr)
 186 {
 187         return (struct blob_attr *) ((char *) attr + blob_pad_len(attr));
 188 }
 189
 190 extern void blob_fill_pad(struct blob_attr *attr);
 191 extern void blob_set_raw_len(struct blob_attr *attr, unsigned int len);
 192 extern bool blob_attr_equal(const struct blob_attr *a1, const struct blob_attr *a2);
 193 extern int blob_buf_init(struct blob_buf *buf, int id);
 194 extern void blob_buf_free(struct blob_buf *buf);
 195 extern bool blob_buf_grow(struct blob_buf *buf, int required);
 196 extern struct blob_attr *blob_new(struct blob_buf *buf, int id, int payload);
 197 extern void *blob_nest_start(struct blob_buf *buf, int id);
 198 extern void blob_nest_end(struct blob_buf *buf, void *cookie);
 199 extern struct blob_attr *blob_put(struct blob_buf *buf, int id, const void *ptr, unsigned int len);
 200 extern bool blob_check_type(const void *ptr, unsigned int len, int type);
 201 extern int blob_parse(struct blob_attr *attr, struct blob_attr **data, const struct blob_attr_info *info, int max);
 202 extern struct blob_attr *blob_memdup(struct blob_attr *attr);
 203 extern struct blob_attr *blob_put_raw(struct blob_buf *buf, const void *ptr, unsigned int len);
 204
 205 static inline struct blob_attr *
 206 blob_put_string(struct blob_buf *buf, int id, const char *str)
 207 {
 208         return blob_put(buf, id, str, strlen(str) + 1);
 209 }
 210
 211 static inline struct blob_attr *
 212 blob_put_u8(struct blob_buf *buf, int id, uint8_t val)
 213 {
 214         return blob_put(buf, id, &val, sizeof(val));
 215 }
 216
 217 static inline struct blob_attr *
 218 blob_put_u16(struct blob_buf *buf, int id, uint16_t val)
 219 {
 220         val = cpu_to_be16(val);
 221         return blob_put(buf, id, &val, sizeof(val));
 222 }
 223
 224 static inline struct blob_attr *
 225 blob_put_u32(struct blob_buf *buf, int id, uint32_t val)
 226 {
 227         val = cpu_to_be32(val);
 228         return blob_put(buf, id, &val, sizeof(val));
 229 }
 230
 231 static inline struct blob_attr *
 232 blob_put_u64(struct blob_buf *buf, int id, uint64_t val)
 233 {
 234         val = cpu_to_be64(val);
 235         return blob_put(buf, id, &val, sizeof(val));
 236 }
 237
 238 #define blob_put_int8   blob_put_u8
 239 #define blob_put_int16  blob_put_u16
 240 #define blob_put_int32  blob_put_u32
 241 #define blob_put_int64  blob_put_u64
 242
 243 #define __blob_for_each_attr(pos, attr, rem) \
 244         for (pos = (struct blob_attr *) attr; \
 245              rem > 0 && (blob_pad_len(pos) <= rem) && \
 246              (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
 247              rem -= blob_pad_len(pos), pos = blob_next(pos))
 248
 249
 250 #define blob_for_each_attr(pos, attr, rem) \
 251         for (rem = attr ? blob_len(attr) : 0, \
 252              pos = (struct blob_attr *) (attr ? blob_data(attr) : NULL); \
 253              rem > 0 && (blob_pad_len(pos) <= rem) && \
 254              (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
 255              rem -= blob_pad_len(pos), pos = blob_next(pos))
 256
 257
 258 #endif