C++ HostInfo::HostName方法代码示例

bool TcpSocket::ConnectImpl(const HostInfo& hostInfo,
                            const std::string& port,
                            IBamIODevice::OpenMode mode)
{
    // skip if we're already connected
    if ( m_state == TcpSocket::ConnectedState ) {
        m_error = TcpSocket::SocketResourceError;
        m_errorString = "socket already connected";
        return false;
    }

    // reset socket state
    m_hostName   = hostInfo.HostName();
    m_mode       = mode;
    m_state      = TcpSocket::UnconnectedState;
    m_error      = TcpSocket::UnknownSocketError;
//    m_localPort  = 0;
    m_remotePort = 0;
//    m_localAddress.Clear();
    m_remoteAddress.Clear();
    m_readBuffer.Clear();

    // fetch candidate addresses for requested host
    vector<HostAddress> addresses = hostInfo.Addresses();
    if ( addresses.empty() ) {
        m_error = TcpSocket::HostNotFoundError;
        m_errorString = "no IP addresses found for host";
        return false;
    }

    // convert port string to integer
    stringstream ss(port);
    uint16_t portNumber(0);
    ss >> portNumber;

    // iterate through adddresses
    vector<HostAddress>::const_iterator addrIter = addresses.begin();
    vector<HostAddress>::const_iterator addrEnd  = addresses.end();
    for ( ; addrIter != addrEnd; ++addrIter) {
        const HostAddress& addr = (*addrIter);

        // try to initialize socket engine with this address
        if ( !InitializeSocketEngine(addr.GetProtocol()) ) {
            // failure to initialize is OK here
            // we'll just try the next available address
            continue;
        }

        // attempt actual connection
        if ( m_engine->Connect(addr, portNumber) ) {

            // if connection successful, update our state & return true
            m_mode = mode;
//            m_localAddress  = m_engine->GetLocalAddress();
//            m_localPort     = m_engine->GetLocalPort();
            m_remoteAddress = m_engine->GetRemoteAddress();
            m_remotePort    = m_engine->GetRemotePort();
            m_cachedSocketDescriptor = m_engine->GetSocketDescriptor();
            m_state = TcpSocket::ConnectedState;
            return true;
        }
    }

    // if we get here, no connection could be made
    m_error = TcpSocket::HostNotFoundError;
    m_errorString = "could not connect to any host addresses";
    return false;
}

HostInfo HostInfo::Lookup(const string& hostname, const string& port) {

    HostInfo result;
    result.SetHostName(hostname);
    set<HostAddress> uniqueAddresses;

#ifdef _WIN32
    WindowsSockInit init;
#endif

    HostAddress address;
    address.SetAddress(hostname);

    // if hostname is an IP string ('0.0.0.0' or IPv6 format)
    // do reverse lookup for host domain name
    //
    // TODO: might just remove this... not sure if proper 'hostname' from IP string is needed
    //
    //       so far, haven't been able to successfully fetch a domain name with reverse DNS
    //       getnameinfo() on test sites just returns original IP string. BUT this is likely a rare
    //       case that client code tries to use an IP string and the connection should work fine
    //       anyway. GetHostName() just won't quite show what I was hoping for. :(
    if ( address.HasIPAddress() ) {

        const uint16_t portNum = static_cast<uint16_t>( atoi(port.c_str()) );

        sockaddr_in  sa4;
        sockaddr_in6 sa6;
        sockaddr* sa = 0;
        BT_SOCKLEN_T saSize = 0;

        // IPv4
        if ( address.GetProtocol() == HostAddress::IPv4Protocol ) {
            sa = (sockaddr*)&sa4;
            saSize = sizeof(sa4);
            memset(&sa4, 0, sizeof(sa4));
            sa4.sin_family = AF_INET;
            sa4.sin_addr.s_addr = htonl(address.GetIPv4Address());
            sa4.sin_port = htons(portNum);
        }

        // IPv6
        else if ( address.GetProtocol() == HostAddress::IPv4Protocol ){
            sa = (sockaddr*)&sa6;
            saSize = sizeof(sa6);
            memset(&sa6, 0, sizeof(sa6));
            sa6.sin6_family = AF_INET6;
            memcpy(sa6.sin6_addr.s6_addr, address.GetIPv6Address().data, sizeof(sa6.sin6_addr.s6_addr));
            sa6.sin6_port = htons(portNum);
        }

        // unknown (should be unreachable)
        else BT_ASSERT_X(false, "HostInfo::Lookup: unknown network protocol");

        // lookup name for IP
        char hbuf[NI_MAXHOST];
        char serv[NI_MAXSERV];
        if ( sa && (getnameinfo(sa, saSize, hbuf, sizeof(hbuf), serv, sizeof(serv), 0) == 0) )
            result.SetHostName(string(hbuf));

        // if no domain name found, just use the original address's IP string
        if ( result.HostName().empty() )
            result.SetHostName(address.GetIPString());

        // store address in HostInfo
        uniqueAddresses.insert(address);
    }

    // otherwise, hostname is a domain name ('www.foo.bar')
    // do 'normal' lookup
    else {

        // setup address lookup 'hints'
        addrinfo hints;
        memset(&hints, 0, sizeof(hints));
        hints.ai_family   = AF_UNSPEC;   // allow either IPv4 or IPv6
        hints.ai_socktype = SOCK_STREAM; // for TCP
        hints.ai_protocol = IPPROTO_TCP;

        // fetch addresses for requested hostname/port
        addrinfo* res;
        int status = getaddrinfo(hostname.c_str(), port.c_str(), &hints, &res );

        // if everything OK
        if ( status == 0 ) {

            // iterate over all IP addresses found
            addrinfo* p = res;
            for ( ; p != NULL; p = p->ai_next ) {

                // IPv4
                if ( p->ai_family == AF_INET ) {
                    sockaddr_in* ipv4 = (sockaddr_in*)p->ai_addr;
                    HostAddress a( ntohl(ipv4->sin_addr.s_addr) );
                    uniqueAddresses.insert(a);
                }

                // IPv6
                else if ( p->ai_family == AF_INET6 ) {
                    sockaddr_in6* ipv6 = (sockaddr_in6*)p->ai_addr;
//.........这里部分代码省略.........