Implement TCP input auto-reconnect

1 files changed, 275 insertions, 0 deletions

diff --git a/src/Socket.cpp b/src/Socket.cpp
new file mode 100644
index 0000000..08cda68
--- /dev/null
+++ b/src/Socket.cpp
@@ -0,0 +1,275 @@
+/*
+   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Her Majesty the
+   Queen in Right of Canada (Communications Research Center Canada)
+
+   Copyright (C) 2018
+   Matthias P. Braendli, matthias.braendli@mpb.li
+
+    http://opendigitalradio.org
+*/
+
+/*
+   This file is part of ODR-DabMod.
+
+   ODR-DabMod 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.
+
+   ODR-DabMod 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 ODR-DabMod.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "Socket.h"
+#include "Log.h"
+#include <fcntl.h>
+
+TCPSocket::TCPSocket()
+{
+    if ((m_sock = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
+        throw std::runtime_error("Can't create TCP 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
+}
+
+TCPSocket::~TCPSocket()
+{
+    if (m_sock != -1) {
+        ::close(m_sock);
+    }
+}
+
+TCPSocket::TCPSocket(TCPSocket&& other)
+{
+    m_sock = other.m_sock;
+
+    if (other.m_sock != -1) {
+        other.m_sock = -1;
+    }
+}
+
+TCPSocket& TCPSocket::operator=(TCPSocket&& other)
+{
+    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)
+{
+    struct sockaddr_in addr;
+    addr.sin_family = PF_INET;
+    addr.sin_addr.s_addr = htons(INADDR_ANY);
+    addr.sin_port = htons(port);
+
+    hostent *host = gethostbyname(hostname.c_str());
+    if (host) {
+        addr.sin_addr = *(in_addr *)(host->h_addr);
+    }
+    else {
+        std::string errstr(strerror(errno));
+        throw std::runtime_error(
+                "could not resolve hostname " +
+                hostname + ":" + std::to_string(port) +
+                " : " + errstr);
+    }
+
+    int ret = ::connect(m_sock, (struct sockaddr*)&addr, sizeof(addr));
+    if (ret == -1 and errno != EINPROGRESS) {
+        std::string errstr(strerror(errno));
+        throw std::runtime_error(
+                "could not connect to " +
+                hostname + ":" + std::to_string(port) +
+                " : " + errstr);
+    }
+}
+
+void TCPSocket::listen(int port)
+{
+    struct sockaddr_in addr;
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(port);
+    addr.sin_addr.s_addr = htonl(INADDR_ANY);
+
+    const int reuse = 1;
+    if (setsockopt(m_sock, SOL_SOCKET, SO_REUSEADDR,
+                &reuse, sizeof(reuse)) < 0) {
+        throw std::runtime_error("Can't reuse address for TCP socket");
+    }
+
+    if (::bind(m_sock, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
+        close();
+        throw std::runtime_error("Can't bind TCP socket");
+    }
+
+    if (::listen(m_sock, 1) < 0) {
+        close();
+        m_sock = -1;
+        throw std::runtime_error("Can't listen TCP socket");
+    }
+
+}
+
+void TCPSocket::close()
+{
+    ::close(m_sock);
+    m_sock = -1;
+}
+
+TCPSocket TCPSocket::accept_with_timeout(int timeout_ms, struct sockaddr_in *client)
+{
+    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) {
+        socklen_t client_len = sizeof(struct sockaddr_in);
+        int sockfd = accept(m_sock, (struct sockaddr*)&client, &client_len);
+        TCPSocket s(sockfd);
+        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::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;
+}
+
+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);
+}