Socket: Implement NetdeviceController socket sharing

Socket/NetdeviceController.cc

@@ -37,8 +37,8 @@
 ///////////////////////////////cc.p////////////////////////////////////////
 
 prefix_ senf::NetdeviceController::NetdeviceController(std::string const & interface_name)
+    : sockfd_ (sockfd())
 {
-    openSocket();
     struct ifreq ifr;
     ::memset( &ifr, 0, sizeof(ifr));
     interface_name.copy( ifr.ifr_name, IFNAMSIZ);
@@ -47,8 +47,8 @@ prefix_ senf::NetdeviceController::NetdeviceController(std::string const & inter
 }
 
 prefix_ senf::NetdeviceController::NetdeviceController(int interface_index)
+    : sockfd_ (sockfd())
 {
-    openSocket();
     ifindex_ = interface_index;
 }
 
@@ -171,14 +171,7 @@ prefix_ int senf::NetdeviceController::interfaceIndex()
 
 prefix_ senf::NetdeviceController::~NetdeviceController()
 {
-    close( sockfd_);
-}
-
-prefix_ void senf::NetdeviceController::openSocket()
-{
-    sockfd_ = ::socket( PF_INET, SOCK_DGRAM, 0);
-    if ( sockfd_ < 0)
-        SENF_THROW_SYSTEM_EXCEPTION("Could not open socket for NetdeviceController.");
+    close( sockfd_->fd);
 }
 
 prefix_ void senf::NetdeviceController::ifrName(ifreq& ifr)
@@ -186,7 +179,7 @@ prefix_ void senf::NetdeviceController::ifrName(ifreq& ifr)
 {
     ::memset( &ifr, 0, sizeof(ifr));
     ifr.ifr_ifindex = ifindex_;
-    if ( ::ioctl( sockfd_, SIOCGIFNAME, &ifr ) < 0 )
+    if ( ::ioctl( sockfd_->fd, SIOCGIFNAME, &ifr ) < 0 )
         SENF_THROW_SYSTEM_EXCEPTION("NetdeviceController")
         << " could not discover the name of the interface with index " << ifindex_ << ".";
 }
@@ -194,10 +187,38 @@ prefix_ void senf::NetdeviceController::ifrName(ifreq& ifr)
 prefix_ void senf::NetdeviceController::doIoctl(ifreq& ifr, int request)
     const
 {
-    if ( ::ioctl( sockfd_, request, &ifr ) < 0 )
+    if ( ::ioctl( sockfd_->fd, request, &ifr ) < 0 )
         SENF_THROW_SYSTEM_EXCEPTION("NetdeviceController::doIoctl failed.");
 }
 
+///////////////////////////////////////////////////////////////////////////
+// senf::NetdeviceController::SockFd
+
+prefix_ senf::NetdeviceController::SockFd::SockFd()
+    : fd (::socket(PF_INET, SOCK_DGRAM, 0))
+{
+    if ( fd < 0)
+        SENF_THROW_SYSTEM_EXCEPTION("Could not open socket for NetdeviceController.");
+}
+
+prefix_ senf::NetdeviceController::SockFd::~SockFd()
+{
+    ::close(fd);
+}
+
+prefix_ senf::NetdeviceController::SockFd::ptr senf::NetdeviceController::sockfd()
+{
+    static boost::weak_ptr<SockFd> sockfd;
+
+    if (sockfd.expired()) {
+        SockFd::ptr newsockfd (new SockFd());
+        sockfd = newsockfd;
+        return newsockfd;
+    }
+    return sockfd.lock();
+        
+}
+
 ///////////////////////////////cc.e////////////////////////////////////////
 #undef prefix_
 //#include "NetdeviceController.mpp"

Socket/NetdeviceController.hh

@@ -29,6 +29,8 @@
 
 // Custom includes
 #include <string>
+#include <boost/shared_ptr.hpp>
+#include <boost/weak_ptr.hpp>
 #include "Protocols/Raw/MACAddress.hh"
 
 
@@ -49,9 +51,9 @@ namespace senf {
     class NetdeviceController
     {
     public:
-        NetdeviceController(std::string const & interface_name);
+        explicit NetdeviceController(std::string const & interface_name);
                                         ///< Construct a new controller for the given interface name.
-        NetdeviceController(int interface_index);
+        explicit NetdeviceController(int interface_index);
                                         ///< Construct a new controller for the given interface index.
         virtual ~NetdeviceController();
 
@@ -90,11 +92,19 @@ namespace senf {
         void up();                      ///< ifconfig up interface
         void down();                    ///< ifconfig down interface
 
+        struct SockFd {
+            typedef boost::shared_ptr<SockFd> ptr;
+            int fd;
+            SockFd();
+            ~SockFd();
+        };
+
+        static SockFd::ptr sockfd();
+
     private:
-        void openSocket();
         void doIoctl(ifreq& ifr, int request) const;
         void ifrName(ifreq& ifr) const;
-        int sockfd_;
+        SockFd::ptr sockfd_;
         int ifindex_;
     };