PInvoke一个用C编译的DLL函数

我有以下C函数

typedef struct ekeycore_ctx_ ekeycore_ctx;

typedef struct ekeycore_enum_ ekeycore_enum;

typedef struct ekeycore_device_ {
    char *serial;
    char *portname;
    char *node;
    BOOL present;
    BOOL used;
} ekeycore_device;

typedef struct ekeycore_simple_ ekeycore_simple;

typedef enum {
    EKEYCORE_OK = 0,              /* everything was fine */
    EKEYCORE_NOMEM = 1,           /* out of memory */
    EKEYCORE_NODEVICE = 2,        /* no devices are available */
    EKEYCORE_TIMEOUT = 3,         /* key did not respond to request */
    EKEYCORE_FAULTY = 4,          /* device has reported faulty/attacked */
    EKEYCORE_UNKNOWN = 5          /* unknown error */
} ekeycore_result;

EKEYCORE_API ekeycore_result ekeycore_simple_get(ekeycore_simple *ctx, unsigned char *buff, size_t buffz)

我需要从C#调用这个函数(ekeycore_simple_get),我该怎么做呢?上面的变量类型如何转换?