如何使用 boost::asio 連接到 unix 域套接字？

Question

我想通過指定套接字端點的路徑名來創建並連接到SOCK_SEQPACKET類型的unix domain socket ，但這無法在boost::asio v1.60 中編譯：

using namespace boost::asio::generic;
seq_packet_protocol proto{AF_UNIX, IPPROTO_SCTP}; // SOCK_SEQPACKET
seq_packet_protocol::socket sock(io_service, proto);
boost::asio::local::basic_endpoint<seq_packet_protocol> ep("/tmp/socket");
sock.connect(ep); // does not compile

你知道如何正確創建一個unix域套接字嗎？

Answer 1

我建議保持簡單：

#include <boost/asio.hpp>

int main() {
    boost::asio::io_service io_service;
    using boost::asio::local::stream_protocol;

    stream_protocol::socket s(io_service);
    s.connect("/tmp/socket");
}

毫無疑問，您可以進入更底層，但我不確定您何時需要它。

更新模仿預定義的stream_protocol ，這里是如何定義seqpacket_protocol ：

住在 Coliru

namespace SeqPacket {
    using namespace boost::asio::local;

    struct seqpacket_protocol
    {
        int type()     const { return IPPROTO_SCTP; }
        int protocol() const { return 0;            }
        int family()   const { return AF_UNIX;      }

        typedef basic_endpoint<seqpacket_protocol> endpoint;
        typedef boost::asio::basic_stream_socket<seqpacket_protocol> socket;
        typedef boost::asio::basic_socket_acceptor<seqpacket_protocol> acceptor;

#if !defined(BOOST_ASIO_NO_IOSTREAM)
        /// The UNIX domain iostream type.
        typedef boost::asio::basic_socket_iostream<seqpacket_protocol> iostream;
#endif // !defined(BOOST_ASIO_NO_IOSTREAM)
    };
}

只需以相同的模式使用它：

int main() {
    boost::asio::io_service io_service;
    using SeqPacket::seqpacket_protocol;

    seqpacket_protocol::socket s(io_service);
    s.connect("socket");
}

Answer 2

要補充sehe的答案，套接字定義是錯誤的，應該是：

typedef boost::asio::basic_seq_packet_socket<seqpacket_protocol> socket;

把它放在一起：

namespace SeqPacket {
    struct seqpacket_protocol
    {
        int type()     const { return SOCK_SEQPACKET; }
        int protocol() const { return 0;            }
        int family()   const { return AF_UNIX;      }

        typedef boost::asio::local::basic_endpoint<seqpacket_protocol> endpoint;
        typedef boost::asio::basic_seq_packet_socket<seqpacket_protocol> socket;
        typedef boost::asio::basic_socket_acceptor<seqpacket_protocol> acceptor;

#if !defined(BOOST_ASIO_NO_IOSTREAM)
        /// The UNIX domain iostream type.
        typedef boost::asio::basic_socket_iostream<seqpacket_protocol> iostream;
#endif // !defined(BOOST_ASIO_NO_IOSTREAM)
    };
}