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_LAST
  43 };
  44
  45 #define BLOB_ATTR_ID_MASK  0x7f000000
  46 #define BLOB_ATTR_ID_SHIFT 24
  47 #define BLOB_ATTR_LEN_MASK 0x00ffffff
  48 #define BLOB_ATTR_ALIGN    4
  49 #define BLOB_ATTR_EXTENDED 0x80000000
  50
  51 struct blob_attr {
  52         uint32_t id_len;
  53         char data[];
  54 } __packed;
  55
  56 struct blob_attr_info {
  57         unsigned int type;
  58         unsigned int minlen;
  59         unsigned int maxlen;
  60         bool (*validate)(const struct blob_attr_info *, struct blob_attr *);
  61 };
  62
  63 struct blob_buf {
  64         struct blob_attr *head;
  65         bool (*grow)(struct blob_buf *buf, int minlen);
  66         int buflen;
  67         void *buf;
  68 };
  69
  70 /*
  71  * blob_data: returns the data pointer for an attribute
  72  */
  73 static inline void *
  74 blob_data(const struct blob_attr *attr)
  75 {
  76         return (void *) attr->data;
  77 }
  78
  79 /*
  80  * blob_id: returns the id of an attribute
  81  */
  82 static inline unsigned int
  83 blob_id(const struct blob_attr *attr)
  84 {
  85         int id = (be32_to_cpu(attr->id_len) & BLOB_ATTR_ID_MASK) >> BLOB_ATTR_ID_SHIFT;
  86         return id;
  87 }
  88
  89 static inline bool
  90 blob_is_extended(const struct blob_attr *attr)
  91 {
  92         return !!(attr->id_len & cpu_to_be32(BLOB_ATTR_EXTENDED));
  93 }
  94
  95 /*
  96  * blob_len: returns the length of the attribute's payload
  97  */
  98 static inline unsigned int
  99 blob_len(const struct blob_attr *attr)
 100 {
 101         return (be32_to_cpu(attr->id_len) & BLOB_ATTR_LEN_MASK) - sizeof(struct blob_attr);
 102 }
 103
 104 /*
 105  * blob_raw_len: returns the complete length of an attribute (including the header)
 106  */
 107 static inline unsigned int
 108 blob_raw_len(const struct blob_attr *attr)
 109 {
 110         return blob_len(attr) + sizeof(struct blob_attr);
 111 }
 112
 113 /*
 114  * blob_pad_len: returns the padded length of an attribute (including the header)
 115  */
 116 static inline unsigned int
 117 blob_pad_len(const struct blob_attr *attr)
 118 {
 119         unsigned int len = blob_raw_len(attr);
 120         len = (len + BLOB_ATTR_ALIGN - 1) & ~(BLOB_ATTR_ALIGN - 1);
 121         return len;
 122 }
 123
 124 static inline uint8_t
 125 blob_get_u8(const struct blob_attr *attr)
 126 {
 127         return *((uint8_t *) attr->data);
 128 }
 129
 130 static inline uint16_t
 131 blob_get_u16(const struct blob_attr *attr)
 132 {
 133         uint16_t *tmp = (uint16_t*)attr->data;
 134         return be16_to_cpu(*tmp);
 135 }
 136
 137 static inline uint32_t
 138 blob_get_u32(const struct blob_attr *attr)
 139 {
 140         uint32_t *tmp = (uint32_t*)attr->data;
 141         return be32_to_cpu(*tmp);
 142 }
 143
 144 static inline uint64_t
 145 blob_get_u64(const struct blob_attr *attr)
 146 {
 147         uint32_t *ptr = (uint32_t *) blob_data(attr);
 148         uint64_t tmp = ((uint64_t) be32_to_cpu(ptr[0])) << 32;
 149         tmp |= be32_to_cpu(ptr[1]);
 150         return tmp;
 151 }
 152
 153 static inline int8_t
 154 blob_get_int8(const struct blob_attr *attr)
 155 {
 156         return blob_get_u8(attr);
 157 }
 158
 159 static inline int16_t
 160 blob_get_int16(const struct blob_attr *attr)
 161 {
 162         return blob_get_u16(attr);
 163 }
 164
 165 static inline int32_t
 166 blob_get_int32(const struct blob_attr *attr)
 167 {
 168         return blob_get_u32(attr);
 169 }
 170
 171 static inline int64_t
 172 blob_get_int64(const struct blob_attr *attr)
 173 {
 174         return blob_get_u64(attr);
 175 }
 176
 177 static inline const char *
 178 blob_get_string(const struct blob_attr *attr)
 179 {
 180         return attr->data;
 181 }
 182
 183 static inline struct blob_attr *
 184 blob_next(const struct blob_attr *attr)
 185 {
 186         return (struct blob_attr *) ((char *) attr + blob_pad_len(attr));
 187 }
 188
 189 extern void blob_fill_pad(struct blob_attr *attr);
 190 extern void blob_set_raw_len(struct blob_attr *attr, unsigned int len);
 191 extern bool blob_attr_equal(const struct blob_attr *a1, const struct blob_attr *a2);
 192 extern int blob_buf_init(struct blob_buf *buf, int id);
 193 extern void blob_buf_free(struct blob_buf *buf);
 194 extern bool blob_buf_grow(struct blob_buf *buf, int required);
 195 extern struct blob_attr *blob_new(struct blob_buf *buf, int id, int payload);
 196 extern void *blob_nest_start(struct blob_buf *buf, int id);
 197 extern void blob_nest_end(struct blob_buf *buf, void *cookie);
 198 extern struct blob_attr *blob_put(struct blob_buf *buf, int id, const void *ptr, unsigned int len);
 199 extern bool blob_check_type(const void *ptr, unsigned int len, int type);
 200 extern int blob_parse(struct blob_attr *attr, struct blob_attr **data, const struct blob_attr_info *info, int max);
 201 extern struct blob_attr *blob_memdup(struct blob_attr *attr);
 202 extern struct blob_attr *blob_put_raw(struct blob_buf *buf, const void *ptr, unsigned int len);
 203
 204 static inline struct blob_attr *
 205 blob_put_string(struct blob_buf *buf, int id, const char *str)
 206 {
 207         return blob_put(buf, id, str, strlen(str) + 1);
 208 }
 209
 210 static inline struct blob_attr *
 211 blob_put_u8(struct blob_buf *buf, int id, uint8_t val)
 212 {
 213         return blob_put(buf, id, &val, sizeof(val));
 214 }
 215
 216 static inline struct blob_attr *
 217 blob_put_u16(struct blob_buf *buf, int id, uint16_t val)
 218 {
 219         val = cpu_to_be16(val);
 220         return blob_put(buf, id, &val, sizeof(val));
 221 }
 222
 223 static inline struct blob_attr *
 224 blob_put_u32(struct blob_buf *buf, int id, uint32_t val)
 225 {
 226         val = cpu_to_be32(val);
 227         return blob_put(buf, id, &val, sizeof(val));
 228 }
 229
 230 static inline struct blob_attr *
 231 blob_put_u64(struct blob_buf *buf, int id, uint64_t val)
 232 {
 233         val = cpu_to_be64(val);
 234         return blob_put(buf, id, &val, sizeof(val));
 235 }
 236
 237 #define blob_put_int8   blob_put_u8
 238 #define blob_put_int16  blob_put_u16
 239 #define blob_put_int32  blob_put_u32
 240 #define blob_put_int64  blob_put_u64
 241
 242 #define __blob_for_each_attr(pos, attr, rem) \
 243         for (pos = (void *) attr; \
 244              rem > 0 && (blob_pad_len(pos) <= rem) && \
 245              (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
 246              rem -= blob_pad_len(pos), pos = blob_next(pos))
 247
 248
 249 #define blob_for_each_attr(pos, attr, rem) \
 250         for (rem = attr ? blob_len(attr) : 0, \
 251              pos = attr ? blob_data(attr) : 0; \
 252              rem > 0 && (blob_pad_len(pos) <= rem) && \
 253              (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
 254              rem -= blob_pad_len(pos), pos = blob_next(pos))
 255
 256
 257 #endif