Start implementing network connectivity.

Change-Id: I82875bfd1c3a086033d22de636d4fb43455ebac3

src/tcpsockets/TCPStream.cpp

@@ -0,0 +1,92 @@
+/*
+   TCPStream.h
+
+   TCPStream class definition. TCPStream provides methods to trasnfer
+   data between peers over a TCP/IP connection.
+
+   ------------------------------------------
+
+   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 "TCPStream.h"
+
+#include <arpa/inet.h>
+#include <unistd.h>
+
+TCPStream::TCPStream(int sd, struct sockaddr_in* address) : m_sd(sd) {
+  char ip[50];
+  inet_ntop(PF_INET, (struct in_addr*)&(address->sin_addr.s_addr), ip,
+            sizeof(ip) - 1);
+  m_peerIP = ip;
+  m_peerPort = ntohs(address->sin_port);
+}
+
+TCPStream::~TCPStream() { close(); }
+
+std::size_t TCPStream::send(const char* buffer, std::size_t len, Error* err) {
+  if (m_sd < 0) {
+    *err = kConnectionClosed;
+    return 0;
+  }
+  ssize_t rv = write(m_sd, buffer, len);
+  if (rv < 0) {
+    *err = kConnectionReset;
+    return 0;
+  }
+  return static_cast<std::size_t>(rv);
+}
+
+std::size_t TCPStream::receive(char* buffer, std::size_t len, Error* err,
+                               int timeout) {
+  if (m_sd < 0) {
+    *err = kConnectionClosed;
+    return 0;
+  }
+  ssize_t rv;
+  if (timeout <= 0)
+    rv = read(m_sd, buffer, len);
+  else if (WaitForReadEvent(timeout))
+    rv = read(m_sd, buffer, len);
+  else {
+    *err = kConnectionTimedOut;
+    return 0;
+  }
+  if (rv < 0) {
+    *err = kConnectionReset;
+    return 0;
+  }
+  return static_cast<std::size_t>(rv);
+}
+
+void TCPStream::close() {
+  if (m_sd >= 0)
+    ::close(m_sd);
+  m_sd = -1;
+}
+
+bool TCPStream::WaitForReadEvent(int timeout) {
+  fd_set sdset;
+  struct timeval tv;
+
+  tv.tv_sec = timeout;
+  tv.tv_usec = 0;
+  FD_ZERO(&sdset);
+  FD_SET(m_sd, &sdset);
+  if (select(m_sd + 1, &sdset, NULL, NULL, &tv) > 0) {
+    return true;
+  }
+  return false;
+}