Function sys_openat

components/lwp/lwp_syscall.c:700–737

* @brief Opens or creates a file relative to a directory file descriptor. * * This system call opens the file specified by `name`, relative to the directory * indicated by `dirfd`, with the specified flags and mode. It provides more * flexibility than `sys_open` for handling files in specific directory contexts. * * @param dirfd The file descriptor of the directory relative to which the file

 * @see sys_open(), sys_read(), sys_write(), sys_close()
 */
sysret_t sys_openat(int dirfd, const char *name, int flag, mode_t mode)
{
#ifdef ARCH_MM_MMU
    int ret = -1;
    rt_size_t len = 0;
    char *kname = RT_NULL;

    len = lwp_user_strlen(name);
    if (len <= 0)
    {
        return -EINVAL;
    }

    kname = (char *)kmem_get(len + 1);
    if (!kname)
    {
        return -ENOMEM;
    }

    lwp_get_from_user(kname, (void *)name, len + 1);
    ret = openat(dirfd, kname, flag, mode);
    if (ret < 0)
    {
        ret = GET_ERRNO();
    }

    kmem_put(kname);

    return ret;
#else
    if (!lwp_user_accessable((void *)name, 1))
    {
        return -EFAULT;
    }
    int ret = openat(dirfd, name, flag, mode);
    return (ret < 0 ? GET_ERRNO() : ret);
#endif
}

/**
 * @brief Closes a file descriptor.