BLOB二进制对象(blob.c/h) 数据结构 struct blob_attr { uint32_t id_len; /** 高1位为extend标志，高7位存储id， * 低24位存储data的内存大小 */ char data[]; } __packed; struct blob_attr_info { unsigned int type; unsigned int minlen; unsigned int maxlen; bool (*validate)(const struct blob_attr_info *, struct blob_attr *); }; struct blob_buf { struct blob_attr *head; bool (*grow)(struct blob_buf *buf, int minlen); int buflen; void *buf; }; 存储结构 blob_buff内存结构 接口说明 获取BLOB属性信息 /** * 返回指向BLOB属性数据区指针 */ static inline void * blob_data(const struct blob_attr *attr) /** * 返回BLOB属性ID */ static inline unsigned int blob_id(const struct blob_attr *attr) /** * 判断BLOB属性扩展标志是否为真 */ static inline bool blob_is_extended(const struct blob_attr *attr) /** * 返回BLOB属性有效存储空间大小 */ static inline unsigned int blob_len(const struct blob_attr *attr) /* * 返回BLOB属性完全存储空间大小(包括头部) */ static inline unsigned int blob_raw_len(const struct blob_attr *attr) /* * 返回BLOB属性填补后存储空间大小(包括头部) */ static inline unsigned int blob_pad_len(const struct blob_attr *attr) 获取BLOB数据信息 static inline uint8_t blob_get_u8(const struct blob_attr *attr) static inline uint16_t blob_get_u16(const struct blob_attr *attr) static inline uint32_t blob_get_u32(const struct blob_attr *attr) static inline uint64_t blob_get_u64(const struct blob_attr *attr) static inline int8_t blob_get_int8(const struct blob_attr *attr) static inline int16_t blob_get_int16(const struct blob_attr *attr) static inline int32_t blob_get_int32(const struct blob_attr *attr) static inline int64_t blob_get_int64(const struct blob_attr *attr) static inline const char * blob_get_string(const struct blob_attr *attr) 设置BLOB数据信息 static inline struct blob_attr * blob_put_string(struct blob_buf *buf, int id, const char *str) static inline struct blob_attr * blob_put_u8(struct blob_buf *buf, int id, uint8_t val) static inline struct blob_attr * blob_put_u16(struct blob_buf *buf, int id, uint16_t val) static inline struct blob_attr * blob_put_u32(struct blob_buf *buf, int id, uint32_t val) static inline struct blob_attr * blob_put_u64(struct blob_buf *buf, int id, uint64_t val) #define blob_put_int8 blob_put_u8 #define blob_put_int16 blob_put_u16 #define blob_put_int32 blob_put_u32 #define blob_put_int64 blob_put_u64 struct blob_attr * blob_put(struct blob_buf *buf, int id, const void *ptr, unsigned int len) /** * ptr - 指向struct blob_attr */ struct blob_attr * blob_put_raw(struct blob_buf *buf, const void *ptr, unsigned int len) 遍历 #define __blob_for_each_attr(pos, attr, rem) #define blob_for_each_attr(pos, attr, rem) 复制 struct blob_attr * blob_memdup(struct blob_attr *attr) 数据类型判断 enum { BLOB_ATTR_UNSPEC, BLOB_ATTR_NESTED, /** 嵌套 */ BLOB_ATTR_BINARY, BLOB_ATTR_STRING, BLOB_ATTR_INT8, BLOB_ATTR_INT16, BLOB_ATTR_INT32, BLOB_ATTR_INT64, BLOB_ATTR_LAST }; bool blob_check_type(const void *ptr, unsigned int len, int type) 嵌套操作 void * blob_nest_start(struct blob_buf *buf, int id) Void blob_nest_end(struct blob_buf *buf, void *cookie) 判断 bool blob_attr_equal(const struct blob_attr *a1, const struct blob_attr *a2) 初始/销毁 /** * 初始化BLOB buffer */ int blob_buf_init(struct blob_buf *buf, int id) /** * 销毁BLOB buffer */ void blob_buf_free(struct blob_buf *buf) 解析BLOB /** * 从attr串中根据info策略过滤，得到的结果存储在data属性数组中 * * @param attr 输入BLOB属性串 * @param data 输出BLOB属性数组 * @param info 属性过滤策略 * @param max data数组大小 */ int blob_parse(struct blob_attr *attr, struct blob_attr **data, const struct blob_attr_info *info, int max) BLOB消息对象(blobmsg.c/h) 数据结构 struct blobmsg_hdr { uint16_t namelen; uint8_t name[]; } __packed; struct blobmsg_policy { const char *name; enum blobmsg_type type; }; 存储结构 blobmsg内存结构 消息类型 enum blobmsg_type { BLOBMSG_TYPE_UNSPEC, BLOBMSG_TYPE_ARRAY, BLOBMSG_TYPE_TABLE, BLOBMSG_TYPE_STRING, BLOBMSG_TYPE_INT64, BLOBMSG_TYPE_INT32, BLOBMSG_TYPE_INT16, BLOBMSG_TYPE_INT8, __BLOBMSG_TYPE_LAST, BLOBMSG_TYPE_LAST = __BLOBMSG_TYPE_LAST - 1, BLOBMSG_TYPE_BOOL = BLOBMSG_TYPE_INT8, }; 接口说明 基本操作 /** * 根据BLOB消息名字长度计算出blobmsg头部大小 */ static inline int blobmsg_hdrlen(unsigned int namelen) /** * 获取BLOB消息名字 */ static inline const char *blobmsg_name(const struct blob_attr *attr) /** * 获取BLOB消息类型 */ static inline int blobmsg_type(const struct blob_attr *attr) /** * 获取BLOB消息数据内容 */ static inline void *blobmsg_data(const struct blob_attr *attr) /** * 获取BLOB消息数据内容大小 */ static inline int blobmsg_data_len(const struct blob_attr *attr) static inline int blobmsg_len(const struct blob_attr *attr) 数据类型判断 /** * 判断BLOBMSG属性类型是否合法 */ bool blobmsg_check_attr(const struct blob_attr *attr, bool name) 设置 int blobmsg_add_field(struct blob_buf *buf, int type, const char *name, const void *data, unsigned int len) static inline int blobmsg_add_u8(struct blob_buf *buf, const char *name, uint8_t val) static inline int blobmsg_add_u16(struct blob_buf *buf, const char *name, uint16_t val) static inline int blobmsg_add_u32(struct blob_buf *buf, const char *name, uint32_t val) static inline int blobmsg_add_u64(struct blob_buf *buf, const char *name, uint64_t val) static inline int blobmsg_add_string(struct blob_buf *buf, const char *name, const char *string) static inline int blobmsg_add_blob(struct blob_buf *buf, struct blob_attr *attr) /** * 格式化设备BLOGMSG */ void blobmsg_printf(struct blob_buf *buf, const char *name, const char *format, ...) 获取 static inline uint8_t blobmsg_get_u8(struct blob_attr *attr) static inline bool blobmsg_get_bool(struct blob_attr *attr) static inline uint16_t blobmsg_get_u16(struct blob_attr *attr) static inline uint32_t blobmsg_get_u32(struct blob_attr *attr) static inline uint64_t blobmsg_get_u64(struct blob_attr *attr) static inline char *blobmsg_get_string(struct blob_attr *attr) 创建 /** * 创建BLOBMSG，返回数据区开始地址 */ void *blobmsg_alloc_string_buffer(struct blob_buf *buf, const char *name, unsigned int maxlen) /** * 扩大BLOGMSG，返回数据区开始地址 */ void *blobmsg_realloc_string_buffer(struct blob_buf *buf, unsigned int maxlen) void blobmsg_add_string_buffer(struct blob_buf *buf) 遍历 #define blobmsg_for_each_attr(pos, attr, rem) 嵌套 static inline void * blobmsg_open_array(struct blob_buf *buf, const char *name) static inline void blobmsg_close_array(struct blob_buf *buf, void *cookie) static inline void *blobmsg_open_table(struct blob_buf *buf, const char *name) static inline void blobmsg_close_table(struct blob_buf *buf, void *cookie) 解析BLOGMSG /** * 从data BLOGMSG串中根据policy策略过滤，得到的结果存储在tb BLOGATTR数组中 * * @param policy 过滤策略 * @param policy_len 策略个数 * @param tb 返回属性数据 * @param len data属性个数 */ int blobmsg_parse(const struct blobmsg_policy *policy, int policy_len, struct blob_attr **tb, void *data, unsigned int len) 例子 把UCI转化为BLOB UCI配置文件: /etc/config/test config policy test option name 'test' option enable '1' option dns '1.1.1.1 2.2.2.2' 定义参数列表: enum { POLICY_ATTR_NAME, /** name */ POLICY_ATTR_ENABLE, /** enable */ POLICY_ATTR_DNS, /** dns */ __POLICY_ATTR_MAX }; static const struct blobmsg_policy policy_attrs[__POLICY_ATTR_MAX] = { [POLICY_ATTR_NAME] = { .name = "name", .type = BLOBMSG_TYPE_STRING }, [POLICY_ATTR_ENABLE] = { .name = "enable", .type = BLOBMSG_TYPE_BOOL }, [POLICY_ATTR_DNS] = { .name = "dns", .type = BLOBMSG_TYPE_ARRAY }, }; /** 定义BLOBMSG_TYPE_ARRAY类型参数的实际数据类型 */ static const struct uci_blob_param_info policy_attr_info[__POLICY_ATTR_MAX] = { [POLICY_ATTR_DNS] = { .type = BLOBMSG_TYPE_STRING }, }; static const struct uci_blob_param_list policy_attr_list = { .n_params = __POLICY_ATTR_MAX, .params = policy_attrs, .info = policy_attr_info, }; 转化为BLOB: static struct uci_context *g_uci_ctx; static struct blob_buf *b; void transform(const char *config) { struct uci_context *ctx = g_uci_ctx; struct uci_package *p = NULL; if (!ctx) { ctx = uci_alloc_context(); g_uci_ctx = ctx; uci_set_confdir(ctx, NULL); } else { p = uci_lookup_package(ctx, config); if (p) uci_unload(ctx, p); } if (uci_load(ctx, config, &p)) return; struct uci_element *e; struct blob_attr *config = NULL; uci_foreach_element(&p->sectons, e) { struct uci_section *s = uci_to_section(e); blob_buf_init(&b, 0); uci_to_blob(&b, s, &policy_attr_list); config = blob_memdup(b.head); /** * do something with `config` * free(config), when not use it */ } } 使用转化后的blob_attr void foo(blob_attr *confg) { struct blob_attr *tb[__POLICY_ATTR_MAX]; blobmsg_parse(policy_attrs, __POLICY_ATTR_MAX, tb, blob_data(config), blob_len(config)); /** * do something with *tb[] */ }