Function sys_gethostbyname2_r

components/lwp/lwp_syscall.c:7249–7405

* @brief Resolves a host name to an address, with support for specifying the address family. * * This function performs a lookup of the specified host name, and resolves it to an address, * while allowing the caller to specify the desired address family (e.g., IPv4 or IPv6). It is * a reentrant version of `gethostbyname2`, meaning it is safe for use in multi-threaded applications. * The resul

 * @see gethostbyname2(), sys_gethostbyname(), sys_socket(), sys_connect(), sys_getaddrinfo()
 */
sysret_t sys_gethostbyname2_r(const char *name, int af, struct hostent *ret,
        char *buf, size_t buflen,
        struct hostent **result, int *err)
{
    int ret_val = -1;
    int sal_ret = -1 , sal_err = -1;
    struct hostent sal_he, sal_tmp;
    struct hostent *sal_result = NULL;
    char *sal_buf = NULL;
    char *k_name  = NULL;
    int len = 0;

#ifdef ARCH_MM_MMU
    if (!lwp_user_accessable((void *)err, sizeof(*err)))
    {
        SET_ERRNO(EFAULT);
        goto __exit;
    }

    if (!lwp_user_accessable((void *)result, sizeof(*result))
    || !lwp_user_accessable((void *)ret, sizeof(*ret))
    || !lwp_user_accessable((void *)buf, buflen))
    {
        /* not all arguments given */
        *err = EFAULT;
        SET_ERRNO(EFAULT);
        goto __exit;
    }

    len = lwp_user_strlen(name);
    if (len <= 0)
    {
        *err = EFAULT;
        SET_ERRNO(EFAULT);
        goto __exit;
    }

    k_name = (char *)kmem_get(len + 1);
    if (!k_name)
    {
        SET_ERRNO(ENOMEM);
        goto __exit;
    }

    if (lwp_get_from_user(k_name, (void *)name, len + 1) < 0)
    {
        SET_ERRNO(EFAULT);
        goto __exit;
    }
#else
    k_name = rt_strdup(name);
    if (k_name == NULL)
    {
        SET_ERRNO(ENOMEM);
        goto __exit;
    }
#endif