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  0xff000000
  46 #define BLOB_ATTR_ID_SHIFT 24
  47 #define BLOB_ATTR_LEN_MASK 0x00ffffff
  48 #define BLOB_ATTR_ALIGN    4
  49
  50 struct blob_attr {
  51         uint32_t id_len;
  52         char data[];
  53 } __packed;
  54
  55 struct blob_attr_info {
  56         unsigned int type;
  57         unsigned int minlen;
  58         unsigned int maxlen;
  59         bool (*validate)(const struct blob_attr_info *, struct blob_attr *);
  60 };
  61
  62 struct blob_buf {
  63         struct blob_attr *head;
  64         bool (*grow)(struct blob_buf *buf, int minlen);
  65         int buflen;
  66         void *buf;
  67 };
  68
  69 /*
  70  * blob_data: returns the data pointer for an attribute
  71  */
  72 static inline void *
  73 blob_data(const struct blob_attr *attr)
  74 {
  75         return (void *) attr->data;
  76 }
  77
  78 /*
  79  * blob_id: returns the id of an attribute
  80  */
  81 static inline unsigned int
  82 blob_id(const struct blob_attr *attr)
  83 {
  84         int id = (be32_to_cpu(attr->id_len) & BLOB_ATTR_ID_MASK) >> BLOB_ATTR_ID_SHIFT;
  85         return id;
  86 }
  87
  88 /*
  89  * blob_len: returns the length of the attribute's payload
  90  */
  91 static inline unsigned int
  92 blob_len(const struct blob_attr *attr)
  93 {
  94         return (be32_to_cpu(attr->id_len) & BLOB_ATTR_LEN_MASK) - sizeof(struct blob_attr);
  95 }
  96
  97 /*
  98  * blob_raw_len: returns the complete length of an attribute (including the header)
  99  */
 100 static inline unsigned int
 101 blob_raw_len(const struct blob_attr *attr)
 102 {
 103         return blob_len(attr) + sizeof(struct blob_attr);
 104 }
 105
 106 /*
 107  * blob_pad_len: returns the padded length of an attribute (including the header)
 108  */
 109 static inline unsigned int
 110 blob_pad_len(const struct blob_attr *attr)
 111 {
 112         int len = blob_raw_len(attr);
 113         len = (len + BLOB_ATTR_ALIGN - 1) & ~(BLOB_ATTR_ALIGN - 1);
 114         return len;
 115 }
 116
 117 static inline uint8_t
 118 blob_get_u8(const struct blob_attr *attr)
 119 {
 120         return *((uint8_t *) attr->data);
 121 }
 122
 123 static inline uint16_t
 124 blob_get_u16(const struct blob_attr *attr)
 125 {
 126         uint16_t *tmp = (uint16_t*)attr->data;
 127         return be16_to_cpu(*tmp);
 128 }
 129
 130 static inline uint32_t
 131 blob_get_u32(const struct blob_attr *attr)
 132 {
 133         uint32_t *tmp = (uint32_t*)attr->data;
 134         return be32_to_cpu(*tmp);
 135 }
 136
 137 static inline uint64_t
 138 blob_get_u64(const struct blob_attr *attr)
 139 {
 140         uint32_t *ptr = blob_data(attr);
 141         uint64_t tmp = ((uint64_t) be32_to_cpu(ptr[0])) << 32;
 142         tmp |= be32_to_cpu(ptr[1]);
 143         return tmp;
 144 }
 145
 146 static inline int8_t
 147 blob_get_int8(const struct blob_attr *attr)
 148 {
 149         return blob_get_u8(attr);
 150 }
 151
 152 static inline int16_t
 153 blob_get_int16(const struct blob_attr *attr)
 154 {
 155         return blob_get_u16(attr);
 156 }
 157
 158 static inline int32_t
 159 blob_get_int32(const struct blob_attr *attr)
 160 {
 161         return blob_get_u32(attr);
 162 }
 163
 164 static inline int64_t
 165 blob_get_int64(const struct blob_attr *attr)
 166 {
 167         return blob_get_u64(attr);
 168 }
 169
 170 static inline const char *
 171 blob_get_string(const struct blob_attr *attr)
 172 {
 173         return attr->data;
 174 }
 175
 176 static inline struct blob_attr *
 177 blob_next(const struct blob_attr *attr)
 178 {
 179         return (struct blob_attr *) ((char *) attr + blob_pad_len(attr));
 180 }
 181
 182 extern void blob_fill_pad(struct blob_attr *attr);
 183 extern void blob_set_raw_len(struct blob_attr *attr, unsigned int len);
 184 extern bool blob_attr_equal(const struct blob_attr *a1, const struct blob_attr *a2);
 185 extern int blob_buf_init(struct blob_buf *buf, int id);
 186 extern void blob_buf_free(struct blob_buf *buf);
 187 extern void blob_buf_grow(struct blob_buf *buf, int required);
 188 extern struct blob_attr *blob_new(struct blob_buf *buf, int id, int payload);
 189 extern void *blob_nest_start(struct blob_buf *buf, int id);
 190 extern void blob_nest_end(struct blob_buf *buf, void *cookie);
 191 extern struct blob_attr *blob_put(struct blob_buf *buf, int id, const void *ptr, int len);
 192 extern bool blob_check_type(const void *ptr, int len, int type);
 193 extern int blob_parse(struct blob_attr *attr, struct blob_attr **data, const struct blob_attr_info *info, int max);
 194 extern struct blob_attr *blob_memdup(struct blob_attr *attr);
 195 extern struct blob_attr *blob_put_raw(struct blob_buf *buf, const void *ptr, int len);
 196
 197 static inline struct blob_attr *
 198 blob_put_string(struct blob_buf *buf, int id, const char *str)
 199 {
 200         return blob_put(buf, id, str, strlen(str) + 1);
 201 }
 202
 203 static inline struct blob_attr *
 204 blob_put_u8(struct blob_buf *buf, int id, uint8_t val)
 205 {
 206         return blob_put(buf, id, &val, sizeof(val));
 207 }
 208
 209 static inline struct blob_attr *
 210 blob_put_u16(struct blob_buf *buf, int id, uint16_t val)
 211 {
 212         val = cpu_to_be16(val);
 213         return blob_put(buf, id, &val, sizeof(val));
 214 }
 215
 216 static inline struct blob_attr *
 217 blob_put_u32(struct blob_buf *buf, int id, uint32_t val)
 218 {
 219         val = cpu_to_be32(val);
 220         return blob_put(buf, id, &val, sizeof(val));
 221 }
 222
 223 static inline struct blob_attr *
 224 blob_put_u64(struct blob_buf *buf, int id, uint64_t val)
 225 {
 226         val = cpu_to_be64(val);
 227         return blob_put(buf, id, &val, sizeof(val));
 228 }
 229
 230 #define blob_put_int8   blob_put_u8
 231 #define blob_put_int16  blob_put_u16
 232 #define blob_put_int32  blob_put_u32
 233 #define blob_put_int64  blob_put_u64
 234
 235 #define __blob_for_each_attr(pos, attr, rem) \
 236         for (pos = (void *) attr; \
 237              rem > 0 && (blob_pad_len(pos) <= rem) && \
 238              (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
 239              rem -= blob_pad_len(pos), pos = blob_next(pos))
 240
 241
 242 #define blob_for_each_attr(pos, attr, rem) \
 243         for (rem = attr ? blob_len(attr) : 0, \
 244              pos = attr ? blob_data(attr) : 0; \
 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 #endif