SSL_read读取1,400字节后,为什么SSL_pending返回0?

时间:2011-09-03 17:59:21

标签: c++ networking openssl

while(1)
{
    read_blocked_on_write=0;

    const int buff_len = 1024;
    char buff[buff_len];

    iResult = SSL_read(ssl, buff, buff_len);

    int ssl_err = SSL_get_error(ssl, iResult);
    if(ssl_err == SSL_ERROR_NONE)
    {
        if(offset + iResult > recvbuflen - 1)
        {
            FD_ZERO(&fdread);
            FD_ZERO(&fdwrite);
            MessageBox(hwnd, TEXT("ERROR"), TEXT("Not enough memory!"), MB_OK | MB_ICONERROR);
            return 1;
        }
        memcpy(recvbuf + offset, buff, iResult);
        offset += iResult;
        if(SSL_pending(ssl))
        {
            continue;
        }
        else
        {
            bFinish = true;
            break;
        }
    }
    else if(ssl_err == SSL_ERROR_ZERO_RETURN)
    {
        bFinish = true;
        break;
    }
    else if(ssl_err == SSL_ERROR_WANT_READ)
    {
        break;
    }
    else if(ssl_err == SSL_ERROR_WANT_WRITE)
    {
        /* We get a WANT_WRITE if we're
        trying to rehandshake and we block on
        a write during that rehandshake.

        We need to wait on the socket to be 
        writeable but reinitiate the read
        when it is */
        read_blocked_on_write=1;
        break;
    }
    else
    {
        FD_ZERO(&fdread);
        FD_ZERO(&fdwrite);
        MessageBox(hwnd, TEXT("ERROR"), TEXT("SSL problem!"), MB_OK | MB_ICONERROR);
        return 1;
    }
}

1 个答案:

答案 0 :(得分:1)

我不是专家,但可能是因为没有什么可读的。您正在读取并移动缓冲区(最多需要几毫秒),然后在该时刻无法读取任何内容时终止。与此同时,您正在处理较低层的网络速度和解密速度。那个时刻没有任何东西可以归还,这一点也不可能。

为什么要检查那里?如果您尝试多路复用或其他什么,不会以非阻塞的方式打开套接字吗?