Replace socket library

1 files changed, 894 insertions, 0 deletions

diff --git a/lib/Socket.cpp b/lib/Socket.cpp
new file mode 100644
index 0000000..d14902e
--- /dev/null
+++ b/lib/Socket.cpp
@@ -0,0 +1,894 @@
+/*
+   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Her Majesty the
+   Queen in Right of Canada (Communications Research Center Canada)
+
+   Copyright (C) 2019
+   Matthias P. Braendli, matthias.braendli@mpb.li
+
+    http://www.opendigitalradio.org
+   */
+/*
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include "Socket.h"
+
+#include <iostream>
+#include <cstdio>
+#include <cstring>
+#include <cerrno>
+#include <fcntl.h>
+#include <poll.h>
+
+namespace Socket {
+
+using namespace std;
+
+void InetAddress::resolveUdpDestination(const std::string& destination, int port)
+{
+    char service[NI_MAXSERV];
+    snprintf(service, NI_MAXSERV-1, "%d", port);
+
+    struct addrinfo hints;
+    memset(&hints, 0, sizeof(struct addrinfo));
+    hints.ai_family = AF_INET;
+    hints.ai_socktype = SOCK_DGRAM; /* Datagram socket */
+    hints.ai_flags = 0;
+    hints.ai_protocol = 0;
+
+    struct addrinfo *result, *rp;
+    int s = getaddrinfo(destination.c_str(), service, &hints, &result);
+    if (s != 0) {
+        throw runtime_error(string("getaddrinfo failed: ") + gai_strerror(s));
+    }
+
+    for (rp = result; rp != nullptr; rp = rp->ai_next) {
+        // Take the first result
+        memcpy(&addr, rp->ai_addr, rp->ai_addrlen);
+        break;
+    }
+
+    freeaddrinfo(result);
+
+    if (rp == nullptr) {
+        throw runtime_error("Could not resolve");
+    }
+}
+
+UDPPacket::UDPPacket() { }
+
+UDPPacket::UDPPacket(size_t initSize) :
+    buffer(initSize)
+{ }
+
+
+UDPSocket::UDPSocket() :
+    m_sock(INVALID_SOCKET)
+{
+    reinit(0, "");
+}
+
+UDPSocket::UDPSocket(int port) :
+    m_sock(INVALID_SOCKET)
+{
+    reinit(port, "");
+}
+
+UDPSocket::UDPSocket(int port, const std::string& name) :
+    m_sock(INVALID_SOCKET)
+{
+    reinit(port, name);
+}
+
+
+void UDPSocket::setBlocking(bool block)
+{
+    int res = fcntl(m_sock, F_SETFL, block ? 0 : O_NONBLOCK);
+    if (res == -1) {
+        throw runtime_error(string("Can't change blocking state of socket: ") + strerror(errno));
+    }
+}
+
+void UDPSocket::reinit(int port)
+{
+    return reinit(port, "");
+}
+
+void UDPSocket::reinit(int port, const std::string& name)
+{
+    if (m_sock != INVALID_SOCKET) {
+        ::close(m_sock);
+    }
+
+    if (port == 0) {
+        // No need to bind to a given port, creating the
+        // socket is enough
+        m_sock = ::socket(AF_INET, SOCK_DGRAM, 0);
+        return;
+    }
+
+    char service[NI_MAXSERV];
+    snprintf(service, NI_MAXSERV-1, "%d", port);
+
+    struct addrinfo hints;
+    memset(&hints, 0, sizeof(struct addrinfo));
+    hints.ai_family = AF_INET;
+    hints.ai_socktype = SOCK_DGRAM; /* Datagram socket */
+    hints.ai_flags = AI_PASSIVE;    /* For wildcard IP address */
+    hints.ai_protocol = 0;          /* Any protocol */
+    hints.ai_canonname = nullptr;
+    hints.ai_addr = nullptr;
+    hints.ai_next = nullptr;
+
+    struct addrinfo *result, *rp;
+    int s = getaddrinfo(name.empty() ? nullptr : name.c_str(),
+            port == 0 ? nullptr : service,
+            &hints, &result);
+    if (s != 0) {
+        throw runtime_error(string("getaddrinfo failed: ") + gai_strerror(s));
+    }
+
+    /* getaddrinfo() returns a list of address structures.
+       Try each address until we successfully bind(2).
+       If socket(2) (or bind(2)) fails, we (close the socket
+       and) try the next address. */
+    for (rp = result; rp != nullptr; rp = rp->ai_next) {
+        int sfd = ::socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+        if (sfd == -1) {
+            continue;
+        }
+
+        if (::bind(sfd, rp->ai_addr, rp->ai_addrlen) == 0) {
+            m_sock = sfd;
+            break;
+        }
+
+        ::close(sfd);
+    }
+
+    freeaddrinfo(result);
+
+    if (rp == nullptr) {
+        throw runtime_error("Could not bind");
+    }
+}
+
+void UDPSocket::close()
+{
+    if (m_sock != INVALID_SOCKET) {
+        ::close(m_sock);
+    }
+
+    m_sock = INVALID_SOCKET;
+}
+
+UDPSocket::~UDPSocket()
+{
+    if (m_sock != INVALID_SOCKET) {
+        ::close(m_sock);
+    }
+}
+
+
+UDPPacket UDPSocket::receive(size_t max_size)
+{
+    UDPPacket packet(max_size);
+    socklen_t addrSize;
+    addrSize = sizeof(*packet.address.as_sockaddr());
+    ssize_t ret = recvfrom(m_sock,
+            packet.buffer.data(),
+            packet.buffer.size(),
+            0,
+            packet.address.as_sockaddr(),
+            &addrSize);
+
+    if (ret == SOCKET_ERROR) {
+        packet.buffer.resize(0);
+
+        // This suppresses the -Wlogical-op warning
+#if EAGAIN == EWOULDBLOCK
+        if (errno == EAGAIN) {
+#else
+        if (errno == EAGAIN or errno == EWOULDBLOCK) {
+#endif
+            return 0;
+        }
+        throw runtime_error(string("Can't receive data: ") + strerror(errno));
+    }
+
+    packet.buffer.resize(ret);
+    return packet;
+}
+
+void UDPSocket::send(UDPPacket& packet)
+{
+    const int ret = sendto(m_sock, packet.buffer.data(), packet.buffer.size(), 0,
+            packet.address.as_sockaddr(), sizeof(*packet.address.as_sockaddr()));
+    if (ret == SOCKET_ERROR && errno != ECONNREFUSED) {
+        throw runtime_error(string("Can't send UDP packet: ") + strerror(errno));
+    }
+}
+
+
+void UDPSocket::send(const std::vector<uint8_t>& data, InetAddress destination)
+{
+    const int ret = sendto(m_sock, data.data(), data.size(), 0,
+            destination.as_sockaddr(), sizeof(*destination.as_sockaddr()));
+    if (ret == SOCKET_ERROR && errno != ECONNREFUSED) {
+        throw runtime_error(string("Can't send UDP packet: ") + strerror(errno));
+    }
+}
+
+void UDPSocket::joinGroup(const char* groupname, const char* if_addr)
+{
+    ip_mreqn group;
+    if ((group.imr_multiaddr.s_addr = inet_addr(groupname)) == INADDR_NONE) {
+        throw runtime_error("Cannot convert multicast group name");
+    }
+    if (!IN_MULTICAST(ntohl(group.imr_multiaddr.s_addr))) {
+        throw runtime_error("Group name is not a multicast address");
+    }
+
+    if (if_addr) {
+        group.imr_address.s_addr = inet_addr(if_addr);
+    }
+    else {
+        group.imr_address.s_addr = htons(INADDR_ANY);
+    }
+    group.imr_ifindex = 0;
+    if (setsockopt(m_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, &group, sizeof(group))
+            == SOCKET_ERROR) {
+        throw runtime_error(string("Can't join multicast group") + strerror(errno));
+    }
+}
+
+void UDPSocket::setMulticastSource(const char* source_addr)
+{
+    struct in_addr addr;
+    if (inet_aton(source_addr, &addr) == 0) {
+        throw runtime_error(string("Can't parse source address") + strerror(errno));
+    }
+
+    if (setsockopt(m_sock, IPPROTO_IP, IP_MULTICAST_IF, &addr, sizeof(addr))
+            == SOCKET_ERROR) {
+        throw runtime_error(string("Can't set source address") + strerror(errno));
+    }
+}
+
+void UDPSocket::setMulticastTTL(int ttl)
+{
+    if (setsockopt(m_sock, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl))
+            == SOCKET_ERROR) {
+        throw runtime_error(string("Can't set multicast ttl") + strerror(errno));
+    }
+}
+
+UDPReceiver::UDPReceiver() { }
+
+UDPReceiver::~UDPReceiver() {
+    m_stop = true;
+    m_sock.close();
+    if (m_thread.joinable()) {
+        m_thread.join();
+    }
+}
+
+void UDPReceiver::start(int port, const string& bindto, const string& mcastaddr, size_t max_packets_queued) {
+    m_port = port;
+    m_bindto = bindto;
+    m_mcastaddr = mcastaddr;
+    m_max_packets_queued = max_packets_queued;
+    m_thread = std::thread(&UDPReceiver::m_run, this);
+}
+
+std::vector<uint8_t> UDPReceiver::get_packet_buffer()
+{
+    if (m_stop) {
+        throw runtime_error("UDP Receiver not running");
+    }
+
+    UDPPacket p;
+    m_packets.wait_and_pop(p);
+
+    return p.buffer;
+}
+
+void UDPReceiver::m_run()
+{
+    // Ensure that stop is set to true in case of exception or return
+    struct SetStopOnDestruct {
+        SetStopOnDestruct(atomic<bool>& stop) : m_stop(stop) {}
+        ~SetStopOnDestruct() { m_stop = true; }
+        private: atomic<bool>& m_stop;
+    } autoSetStop(m_stop);
+
+    if (IN_MULTICAST(ntohl(inet_addr(m_mcastaddr.c_str())))) {
+        m_sock.reinit(m_port, m_mcastaddr);
+        m_sock.setMulticastSource(m_bindto.c_str());
+        m_sock.joinGroup(m_mcastaddr.c_str(), m_bindto.c_str());
+    }
+    else {
+        m_sock.reinit(m_port, m_bindto);
+    }
+
+    while (not m_stop) {
+        constexpr size_t packsize = 8192;
+        try {
+            auto packet = m_sock.receive(packsize);
+            if (packet.buffer.size() == packsize) {
+                // TODO replace fprintf
+                fprintf(stderr, "Warning, possible UDP truncation\n");
+            }
+
+            // If this blocks, the UDP socket will lose incoming packets
+            m_packets.push_wait_if_full(packet, m_max_packets_queued);
+        }
+        catch (const std::runtime_error& e) {
+            // TODO replace fprintf
+            // TODO handle intr
+            fprintf(stderr, "Socket error: %s\n", e.what());
+            m_stop = true;
+        }
+    }
+}
+
+
+TCPSocket::TCPSocket()
+{
+}
+
+TCPSocket::~TCPSocket()
+{
+    if (m_sock != -1) {
+        ::close(m_sock);
+    }
+}
+
+TCPSocket::TCPSocket(TCPSocket&& other) :
+    m_sock(other.m_sock),
+    m_remote_address(move(other.m_remote_address))
+{
+    if (other.m_sock != -1) {
+        other.m_sock = -1;
+    }
+}
+
+TCPSocket& TCPSocket::operator=(TCPSocket&& other)
+{
+    swap(m_remote_address, other.m_remote_address);
+
+    m_sock = other.m_sock;
+    if (other.m_sock != -1) {
+        other.m_sock = -1;
+    }
+
+    return *this;
+}
+
+bool TCPSocket::valid() const
+{
+    return m_sock != -1;
+}
+
+void TCPSocket::connect(const std::string& hostname, int port)
+{
+    if (m_sock != INVALID_SOCKET) {
+        throw std::logic_error("You may only connect an invalid TCPSocket");
+    }
+
+    char service[NI_MAXSERV];
+    snprintf(service, NI_MAXSERV-1, "%d", port);
+
+    /* Obtain address(es) matching host/port */
+    struct addrinfo hints;
+    memset(&hints, 0, sizeof(struct addrinfo));
+    hints.ai_family = AF_INET;
+    hints.ai_socktype = SOCK_STREAM;
+    hints.ai_flags = 0;
+    hints.ai_protocol = 0;
+
+    struct addrinfo *result, *rp;
+    int s = getaddrinfo(hostname.c_str(), service, &hints, &result);
+    if (s != 0) {
+        throw runtime_error(string("getaddrinfo failed: ") + gai_strerror(s));
+    }
+
+    /* getaddrinfo() returns a list of address structures.
+       Try each address until we successfully connect(2).
+       If socket(2) (or connect(2)) fails, we (close the socket
+       and) try the next address. */
+
+    for (rp = result; rp != nullptr; rp = rp->ai_next) {
+        int sfd = ::socket(rp->ai_family, rp->ai_socktype,
+                rp->ai_protocol);
+        if (sfd == -1)
+            continue;
+
+        int ret = ::connect(sfd, rp->ai_addr, rp->ai_addrlen);
+        if (ret != -1 or (ret == -1 and errno == EINPROGRESS)) {
+            // As the TCPClient could set the socket to nonblocking, we
+            // must handle EINPROGRESS here
+            m_sock = sfd;
+            break;
+        }
+
+        ::close(sfd);
+    }
+
+    if (m_sock != INVALID_SOCKET) {
+#if defined(HAVE_SO_NOSIGPIPE)
+        int val = 1;
+        if (setsockopt(m_sock, SOL_SOCKET, SO_NOSIGPIPE, &val, sizeof(val))
+                == SOCKET_ERROR) {
+            throw std::runtime_error("Can't set SO_NOSIGPIPE");
+        }
+#endif
+    }
+
+    freeaddrinfo(result);           /* No longer needed */
+
+    if (rp == nullptr) {
+        throw runtime_error("Could not connect");
+    }
+
+}
+
+void TCPSocket::listen(int port, const string& name)
+{
+    if (m_sock != INVALID_SOCKET) {
+        throw std::logic_error("You may only listen with an invalid TCPSocket");
+    }
+
+    char service[NI_MAXSERV];
+    snprintf(service, NI_MAXSERV-1, "%d", port);
+
+    struct addrinfo hints;
+    memset(&hints, 0, sizeof(struct addrinfo));
+    hints.ai_family = AF_INET;
+    hints.ai_socktype = SOCK_STREAM;
+    hints.ai_flags = AI_PASSIVE;    /* For wildcard IP address */
+    hints.ai_protocol = 0;
+    hints.ai_canonname = nullptr;
+    hints.ai_addr = nullptr;
+    hints.ai_next = nullptr;
+
+    struct addrinfo *result, *rp;
+    int s = getaddrinfo(name.empty() ? nullptr : name.c_str(), service, &hints, &result);
+    if (s != 0) {
+        throw runtime_error(string("getaddrinfo failed: ") + gai_strerror(s));
+    }
+
+    /* getaddrinfo() returns a list of address structures.
+       Try each address until we successfully bind(2).
+       If socket(2) (or bind(2)) fails, we (close the socket
+       and) try the next address. */
+    for (rp = result; rp != nullptr; rp = rp->ai_next) {
+        int sfd = ::socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+        if (sfd == -1) {
+            continue;
+        }
+
+        if (::bind(sfd, rp->ai_addr, rp->ai_addrlen) == 0) {
+            m_sock = sfd;
+            break;
+        }
+
+        ::close(sfd);
+    }
+
+    freeaddrinfo(result);
+
+    if (m_sock != INVALID_SOCKET) {
+#if defined(HAVE_SO_NOSIGPIPE)
+        int val = 1;
+        if (setsockopt(m_sock, SOL_SOCKET, SO_NOSIGPIPE,
+                    &val, sizeof(val)) < 0) {
+            throw std::runtime_error("Can't set SO_NOSIGPIPE");
+        }
+#endif
+
+        int ret = ::listen(m_sock, 0);
+        if (ret == -1) {
+            throw std::runtime_error(string("Could not listen: ") + strerror(errno));
+        }
+    }
+
+    if (rp == nullptr) {
+        throw runtime_error("Could not bind");
+    }
+}
+
+void TCPSocket::close()
+{
+    ::close(m_sock);
+    m_sock = -1;
+}
+
+TCPSocket TCPSocket::accept(int timeout_ms)
+{
+    if (timeout_ms == 0) {
+        InetAddress remote_addr;
+        socklen_t client_len = sizeof(remote_addr.addr);
+        int sockfd = ::accept(m_sock, remote_addr.as_sockaddr(), &client_len);
+        TCPSocket s(sockfd, remote_addr);
+        return s;
+    }
+    else {
+        struct pollfd fds[1];
+        fds[0].fd = m_sock;
+        fds[0].events = POLLIN;
+
+        int retval = poll(fds, 1, timeout_ms);
+
+        if (retval == -1) {
+            std::string errstr(strerror(errno));
+            throw std::runtime_error("TCP Socket accept error: " + errstr);
+        }
+        else if (retval > 0) {
+            InetAddress remote_addr;
+            socklen_t client_len = sizeof(remote_addr.addr);
+            int sockfd = ::accept(m_sock, remote_addr.as_sockaddr(), &client_len);
+            TCPSocket s(sockfd, remote_addr);
+            return s;
+        }
+        else {
+            TCPSocket s(-1);
+            return s;
+        }
+    }
+}
+
+ssize_t TCPSocket::sendall(const void *buffer, size_t buflen)
+{
+    uint8_t *buf = (uint8_t*)buffer;
+    while (buflen > 0) {
+        /* On Linux, the MSG_NOSIGNAL flag ensures that the process
+         * would not receive a SIGPIPE and die.
+         * Other systems have SO_NOSIGPIPE set on the socket for the
+         * same effect. */
+#if defined(HAVE_MSG_NOSIGNAL)
+        const int flags = MSG_NOSIGNAL;
+#else
+        const int flags = 0;
+#endif
+        ssize_t sent = ::send(m_sock, buf, buflen, flags);
+        if (sent < 0) {
+            return -1;
+        }
+        else {
+            buf += sent;
+            buflen -= sent;
+        }
+    }
+    return buflen;
+}
+
+ssize_t TCPSocket::send(const void* data, size_t size, int timeout_ms)
+{
+    if (timeout_ms) {
+        struct pollfd fds[1];
+        fds[0].fd = m_sock;
+        fds[0].events = POLLOUT;
+
+        const int retval = poll(fds, 1, timeout_ms);
+
+        if (retval == -1) {
+            throw std::runtime_error(string("TCP Socket send error on poll(): ") + strerror(errno));
+        }
+        else if (retval == 0) {
+            // Timed out
+            return 0;
+        }
+    }
+
+    /* On Linux, the MSG_NOSIGNAL flag ensures that the process would not
+     * receive a SIGPIPE and die.
+     * Other systems have SO_NOSIGPIPE set on the socket for the same effect. */
+#if defined(HAVE_MSG_NOSIGNAL)
+    const int flags = MSG_NOSIGNAL;
+#else
+    const int flags = 0;
+#endif
+    const ssize_t ret = ::send(m_sock, (const char*)data, size, flags);
+
+    if (ret == SOCKET_ERROR) {
+            throw std::runtime_error(string("TCP Socket send error: ") + strerror(errno));
+    }
+    return ret;
+}
+
+ssize_t TCPSocket::recv(void *buffer, size_t length, int flags)
+{
+    ssize_t ret = ::recv(m_sock, buffer, length, flags);
+    if (ret == -1) {
+        std::string errstr(strerror(errno));
+        throw std::runtime_error("TCP receive error: " + errstr);
+    }
+    return ret;
+}
+
+ssize_t TCPSocket::recv(void *buffer, size_t length, int flags, int timeout_ms)
+{
+    struct pollfd fds[1];
+    fds[0].fd = m_sock;
+    fds[0].events = POLLIN;
+
+    int retval = poll(fds, 1, timeout_ms);
+
+    if (retval == -1 and errno == EINTR) {
+        throw Interrupted();
+    }
+    else if (retval == -1) {
+        std::string errstr(strerror(errno));
+        throw std::runtime_error("TCP receive with poll() error: " + errstr);
+    }
+    else if (retval > 0 and (fds[0].revents | POLLIN)) {
+        ssize_t ret = ::recv(m_sock, buffer, length, flags);
+        if (ret == -1) {
+            if (errno == ECONNREFUSED) {
+                return 0;
+            }
+            std::string errstr(strerror(errno));
+            throw std::runtime_error("TCP receive after poll() error: " + errstr);
+        }
+        return ret;
+    }
+    else {
+        throw Timeout();
+    }
+}
+
+TCPSocket::TCPSocket(int sockfd) :
+    m_sock(sockfd),
+    m_remote_address()
+{ }
+
+TCPSocket::TCPSocket(int sockfd, InetAddress remote_address) :
+    m_sock(sockfd),
+    m_remote_address(remote_address)
+{ }
+
+void TCPClient::connect(const std::string& hostname, int port)
+{
+    m_hostname = hostname;
+    m_port = port;
+    reconnect();
+}
+
+ssize_t TCPClient::recv(void *buffer, size_t length, int flags, int timeout_ms)
+{
+    try {
+        ssize_t ret = m_sock.recv(buffer, length, flags, timeout_ms);
+
+        if (ret == 0) {
+            m_sock.close();
+
+            TCPSocket newsock;
+            m_sock = std::move(newsock);
+            reconnect();
+        }
+
+        return ret;
+    }
+    catch (const TCPSocket::Interrupted&) {
+        return -1;
+    }
+    catch (const TCPSocket::Timeout&) {
+        return 0;
+    }
+
+    return 0;
+}
+
+void TCPClient::reconnect()
+{
+    int flags = fcntl(m_sock.m_sock, F_GETFL);
+    if (fcntl(m_sock.m_sock, F_SETFL, flags | O_NONBLOCK) == -1) {
+        std::string errstr(strerror(errno));
+        throw std::runtime_error("TCP: Could not set O_NONBLOCK: " + errstr);
+    }
+
+    m_sock.connect(m_hostname, m_port);
+}
+
+TCPConnection::TCPConnection(TCPSocket&& sock) :
+            queue(),
+            m_running(true),
+            m_sender_thread(),
+            m_sock(move(sock))
+{
+#if MISSING_OWN_ADDR
+    auto own_addr = m_sock.getOwnAddress();
+    auto addr = m_sock.getRemoteAddress();
+    etiLog.level(debug) << "New TCP Connection on port " <<
+        own_addr.getPort() << " from " <<
+        addr.getHostAddress() << ":" << addr.getPort();
+#endif
+    m_sender_thread = std::thread(&TCPConnection::process, this);
+}
+
+TCPConnection::~TCPConnection()
+{
+    m_running = false;
+    vector<uint8_t> termination_marker;
+    queue.push(termination_marker);
+    m_sender_thread.join();
+}
+
+void TCPConnection::process()
+{
+    while (m_running) {
+        vector<uint8_t> data;
+        queue.wait_and_pop(data);
+
+        if (data.empty()) {
+            // empty vector is the termination marker
+            m_running = false;
+            break;
+        }
+
+        try {
+            ssize_t remaining = data.size();
+            const uint8_t *buf = reinterpret_cast<const uint8_t*>(data.data());
+            const int timeout_ms = 10; // Less than one ETI frame
+
+            while (m_running and remaining > 0) {
+                const ssize_t sent = m_sock.send(buf, remaining, timeout_ms);
+                if (sent < 0 or sent > remaining) {
+                    throw std::logic_error("Invalid TCPSocket::send() return value");
+                }
+                remaining -= sent;
+                buf += sent;
+            }
+        }
+        catch (const std::runtime_error& e) {
+            m_running = false;
+        }
+    }
+
+#if MISSING_OWN_ADDR
+    auto own_addr = m_sock.getOwnAddress();
+    auto addr = m_sock.getRemoteAddress();
+    etiLog.level(debug) << "Dropping TCP Connection on port " <<
+        own_addr.getPort() << " from " <<
+        addr.getHostAddress() << ":" << addr.getPort();
+#endif
+}
+
+
+TCPDataDispatcher::TCPDataDispatcher(size_t max_queue_size) :
+    m_max_queue_size(max_queue_size)
+{
+}
+
+TCPDataDispatcher::~TCPDataDispatcher()
+{
+    m_running = false;
+    m_connections.clear();
+    m_listener_socket.close();
+    if (m_listener_thread.joinable()) {
+        m_listener_thread.join();
+    }
+}
+
+void TCPDataDispatcher::start(int port, const string& address)
+{
+    m_listener_socket.listen(port, address);
+
+    m_running = true;
+    m_listener_thread = std::thread(&TCPDataDispatcher::process, this);
+}
+
+void TCPDataDispatcher::write(const vector<uint8_t>& data)
+{
+    if (not m_running) {
+        throw runtime_error(m_exception_data);
+    }
+
+    for (auto& connection : m_connections) {
+        connection.queue.push(data);
+    }
+
+    m_connections.remove_if(
+            [&](const TCPConnection& conn){ return conn.queue.size() > m_max_queue_size; });
+}
+
+void TCPDataDispatcher::process()
+{
+    try {
+        const int timeout_ms = 1000;
+
+        while (m_running) {
+            // Add a new TCPConnection to the list, constructing it from the client socket
+            auto sock = m_listener_socket.accept(timeout_ms);
+            if (sock.valid()) {
+                m_connections.emplace(m_connections.begin(), move(sock));
+            }
+        }
+    }
+    catch (const std::runtime_error& e) {
+        m_exception_data = string("TCPDataDispatcher error: ") + e.what();
+        m_running = false;
+    }
+}
+
+TCPReceiveServer::TCPReceiveServer(size_t blocksize) :
+    m_blocksize(blocksize)
+{
+}
+
+void TCPReceiveServer::start(int listen_port, const std::string& address)
+{
+    m_listener_socket.listen(listen_port, address);
+
+    m_running = true;
+    m_listener_thread = std::thread(&TCPReceiveServer::process, this);
+}
+
+TCPReceiveServer::~TCPReceiveServer()
+{
+    m_running = false;
+    if (m_listener_thread.joinable()) {
+        m_listener_thread.join();
+    }
+}
+
+vector<uint8_t> TCPReceiveServer::receive()
+{
+    vector<uint8_t> buffer;
+    m_queue.try_pop(buffer);
+
+    // we can ignore try_pop()'s return value, because
+    // if it is unsuccessful the buffer is not touched.
+    return buffer;
+}
+
+void TCPReceiveServer::process()
+{
+    constexpr int timeout_ms = 1000;
+    constexpr int disconnect_timeout_ms = 10000;
+    constexpr int max_num_timeouts = disconnect_timeout_ms / timeout_ms;
+
+    while (m_running) {
+        auto sock = m_listener_socket.accept(timeout_ms);
+
+        int num_timeouts = 0;
+
+        while (m_running and sock.valid()) {
+            try {
+                vector<uint8_t> buf(m_blocksize);
+                ssize_t r = sock.recv(buf.data(), buf.size(), 0, timeout_ms);
+                if (r < 0) {
+                    throw logic_error("Invalid recv return value");
+                }
+                else {
+                    buf.resize(r);
+                    m_queue.push(move(buf));
+                }
+            }
+            catch (const TCPSocket::Interrupted&) {
+                break;
+            }
+            catch (const TCPSocket::Timeout&) {
+                num_timeouts++;
+            }
+
+            if (num_timeouts > max_num_timeouts) {
+                sock.close();
+            }
+        }
+    }
+}
+
+}