Diff: UDPSocket.cpp

Revision:

0:1f77255a22f5

Child:

1:8080965f5d76

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/UDPSocket.cpp	Tue Jun 26 13:16:26 2012 +0000
@@ -0,0 +1,205 @@
+/* Copyright (C) 2012 mbed.org, MIT License
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+ * and associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute,
+ * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or
+ * substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
+ * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include "UDPSocket.h"
+#include "bsd_socket.h"
+
+#include <cstring>
+
+using std::memset;
+
+UDPSocket::UDPSocket() : m_sock(-1)
+{
+}
+
+UDPSocket::~UDPSocket()
+{
+  close(); //Don't want to leak
+}
+
+int UDPSocket::bind(int port)
+{
+  int ret = init();
+  if( ret < 0 ) 
+  {
+    return -1;
+  }
+  
+  struct sockaddr_in localHost;
+  std::memset(&localHost, 0, sizeof(localHost));
+ 
+  localHost.sin_family = AF_INET;
+  localHost.sin_port = htons(port);
+  localHost.sin_addr.s_addr = INADDR_ANY;
+  
+  ret = ::bind(m_sock, (const struct sockaddr *)&localHost, sizeof(localHost));
+  if (ret < 0)
+  {
+    close();
+    return -1;
+  }
+
+  return 0;
+}
+
+// -1 if unsuccessful, else number of bytes written
+int UDPSocket::sendTo(uint8_t* data, int length, char* host, int port, int timeout)
+{
+  if( m_sock < 0 )
+  {
+    return -1;
+  }
+  
+  struct sockaddr_in remoteHost;
+ 
+  //Populate m_remoteHost
+  std::memset(&remoteHost, 0, sizeof(struct sockaddr_in));
+
+  //Resolve DNS address or populate hard-coded IP address
+  struct hostent *server = ::gethostbyname(host);
+  if(server == NULL)
+  {
+    return -1; //Could not resolve address
+  }
+  std::memcpy((char*)&remoteHost.sin_addr.s_addr, (char*)server->h_addr_list[0], server->h_length);
+
+  remoteHost.sin_family = AF_INET;
+  remoteHost.sin_port = htons(port);
+
+  size_t writtenLen = 0;
+  struct timeval t_val; //t_val will be decremented on each call to select()
+  t_val.tv_sec = timeout / 1000;
+  t_val.tv_usec = (timeout - (t_val.tv_sec * 1000)) * 1000;
+  while(writtenLen < length)
+  {
+    //Wait for socket to be writeable
+    //Creating FS set
+    fd_set socksSet;
+    FD_ZERO(&socksSet);
+    FD_SET(m_sock, &socksSet);
+
+    int ret = ::select(FD_SETSIZE, NULL, &socksSet, NULL, &t_val);
+    if(ret <= 0 || !FD_ISSET(m_sock, &socksSet))
+    {
+      return writtenLen; //Timeout -- FIXME should we return -1 or writtenLength ?
+    }
+
+    ret = ::sendto(m_sock, data + writtenLen, length - writtenLen, 0, (const struct sockaddr *)&remoteHost, sizeof(remoteHost));
+    if( ret > 0)
+    {
+      writtenLen += ret;
+      continue;
+    }
+    else if( ret == 0 )
+    {
+      return writtenLen; //Connection was closed by server -- FIXME how do we signal that the connection was closed ?
+    }
+    else
+    {
+      return -1; //Connnection error
+    }
+  }
+  
+  return writtenLen;
+}
+
+// -1 if unsuccessful, else number of bytes received
+int UDPSocket::receiveFrom(uint8_t* data, int length, char** host, int* port, int timeout)
+{
+  if( m_sock < 0 )
+  {
+    return -1;
+  }
+
+  struct sockaddr_in remoteHost;
+ 
+  //Populate m_remoteHost
+  std::memset(&remoteHost, 0, sizeof(struct sockaddr_in));
+  
+  socklen_t remoteHostLen = sizeof(remoteHost);
+
+  size_t readLen = 0;
+  struct timeval t_val; //t_val will be decremented on each call to select()
+  t_val.tv_sec = timeout / 1000;
+  t_val.tv_usec = (timeout - (t_val.tv_sec * 1000)) * 1000;
+  
+  //No loop here as we don't want to mix packets from different sources
+  do
+  {
+    //Wait for socket to be readable
+    //Creating FS set
+    fd_set socksSet;
+    FD_ZERO(&socksSet);
+    FD_SET(m_sock, &socksSet);
+    int ret = ::select(FD_SETSIZE, &socksSet, NULL, NULL, &t_val);
+    if(ret <= 0 || !FD_ISSET(m_sock, &socksSet))
+    {
+      break; //Timeout -- FIXME should we return -1 or writtenLength ?
+    }
+    
+    ret = ::recvfrom(m_sock, data + readLen, length - readLen, 0, (struct sockaddr*)&remoteHost, &remoteHostLen);
+    if( ret > 0)
+    {
+      readLen += ret;
+    }
+    else if( ret == 0 )
+    {
+      //Connection was closed by server -- FIXME how do we signal that the connection was closed ?
+      //Continue and populate address
+    }
+    else
+    {
+      return -1; //Connection error
+    }
+  } while(0);
+  
+  static char hostBuf[16];
+  inet_ntoa_r(remoteHost.sin_addr, hostBuf, sizeof(hostBuf));
+  
+  *host = hostBuf;
+  *port = ntohs(remoteHost.sin_port);
+  
+  return readLen;
+}
+
+int UDPSocket::close()
+{
+  if( m_sock < 0 )
+  {
+    return -1;
+  }
+
+  ::close(m_sock);
+  m_sock = -1;
+  
+  return 0;
+}
+
+int UDPSocket::init()
+{
+  if( m_sock != -1 )
+  {
+    return -1;
+  }
+  m_sock = ::socket(AF_INET, SOCK_DGRAM, 0); //UDP socket
+  if (m_sock < 0)
+  {
+    return -1; //Could not create socket (Out of memory / available descriptors)
+  }
+  return 0;
+}