Start implementing network connectivity.

Change-Id: I82875bfd1c3a086033d22de636d4fb43455ebac3

src/tcpsockets/TCPAcceptor.cpp

@@ -0,0 +1,86 @@
+/*
+   TCPAcceptor.cpp
+
+   TCPAcceptor class definition. TCPAcceptor provides methods to passively
+   establish TCP/IP connections with clients.
+
+   ------------------------------------------
+
+   Copyright © 2013 [Vic Hargrave - http://vichargrave.com]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+#include "TCPAcceptor.h"
+
+#include <cstdio>
+#include <cstring>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <unistd.h>
+
+TCPAcceptor::TCPAcceptor(int port, const char* address)
+    : m_lsd(0), m_port(port), m_address(address), m_listening(false) {}
+
+TCPAcceptor::~TCPAcceptor() {
+  if (m_lsd > 0) {
+    close(m_lsd);
+  }
+}
+
+int TCPAcceptor::start() {
+  if (m_listening) return 0;
+
+  m_lsd = socket(PF_INET, SOCK_STREAM, 0);
+  struct sockaddr_in address;
+
+  std::memset(&address, 0, sizeof(address));
+  address.sin_family = PF_INET;
+  address.sin_port = htons(m_port);
+  if (m_address.size() > 0) {
+    inet_pton(PF_INET, m_address.c_str(), &(address.sin_addr));
+  } else {
+    address.sin_addr.s_addr = INADDR_ANY;
+  }
+
+  int optval = 1;
+  setsockopt(m_lsd, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof optval);
+
+  int result = bind(m_lsd, (struct sockaddr*)&address, sizeof(address));
+  if (result != 0) {
+    perror("bind() failed");
+    return result;
+  }
+
+  result = listen(m_lsd, 5);
+  if (result != 0) {
+    perror("listen() failed");
+    return result;
+  }
+  m_listening = true;
+  return result;
+}
+
+std::unique_ptr<TCPStream> TCPAcceptor::accept() {
+  if (!m_listening) return nullptr;
+
+  struct sockaddr_in address;
+  socklen_t len = sizeof(address);
+  std::memset(&address, 0, sizeof(address));
+  int sd = ::accept(m_lsd, (struct sockaddr*)&address, &len);
+  if (sd < 0) {
+    perror("accept() failed");
+    return nullptr;
+  }
+  return std::unique_ptr<TCPStream>(new TCPStream(sd, &address));
+}