boost::asio::udp 异步响应未完全收到

Question

说明

我的程序向服务器发送一个 udp 数据报。使用 wireshark 我看到了来自服务器的查询和响应（79 字节）。

发送功能

void Query::start_send(const std::string data, const QueryType queryType) {
    boost::shared_ptr<std::string> message(new std::string(data));
    socket.async_send_to(boost::asio::buffer(*message), endPoint,
        boost::bind(&Query::handler_send, this, message,
            boost::asio::placeholders::error,
            boost::asio::placeholders::bytes_transferred));
    this->queryType = queryType;
}

启动接收功能

void Query::start_receive() {
    socket.async_receive_from(
        boost::asio::buffer(receiveBuffer, receiveBuffer.max_size()), endPoint,
        boost::bind(&Query::handler_receive, this,
            boost::asio::placeholders::error,
            boost::asio::placeholders::bytes_transferred));
}

接收处理程序

void Query::handler_receive(const boost::system::error_code& error, std::size_t bytes_transferred)
{
    if (!error || error == boost::asio::error::message_size) {
        std::cout << "Bytes transferred " << bytes_transferred << std::endl << strlen((char*)this->receiveBuffer.data()) << std::endl;
    }
    else {
        std::cout << "Receive failed" << std::endl << error.value() << std::endl << error.message() << std::endl;
    }
}

控制台输出

Bytes transferred 79
11

bytes_transferred 值是正确的，但我的响应缓冲区（字符向量）"receiveBuffer" 仅包含 11 个字节而不是 79 个字节。

Wireshark

正在发送

回应

Answer 1

您的问题是 strlen((char*)this->receiveBuffer.data())。

strlen 接受以 nul 结尾的 C 字符串作为输入。所以遇到字节00.

就停止计数

您似乎收到混合 binary/text 数据。您不能简单地将其作为字符串打印出来。

boost::asio::udp 异步响应未完全收到

boost::asio::udp async response is not entirely received

c++

udp

datagram

packet

boost-asio

说明