add EthernetHandleSet implementation for Linux

src/hal/ethernet/linux/ethernet_linux.c

@@ -23,6 +23,7 @@
 
 #include <sys/socket.h>
 #include <sys/ioctl.h>
+#include <sys/select.h>
 #include <linux/if_packet.h>
 #include <linux/if_ether.h>
 #include <linux/if_arp.h>
@@ -40,6 +41,60 @@ struct sEthernetSocket {
     struct sockaddr_ll socketAddress;
 };
 
+struct sEthernetHandleSet {
+    fd_set handles;
+    int maxHandle;
+};
+
+EthernetHandleSet
+EthernetHandleSet_new(void)
+{
+    EthernetHandleSet result = (EthernetHandleSet) GLOBAL_MALLOC(sizeof(struct sEthernetHandleSet));
+
+    if (result != NULL) {
+        FD_ZERO(&result->handles);
+        result->maxHandle = -1;
+    }
+
+    return result;
+}
+
+void
+EthernetHandleSet_addSocket(EthernetHandleSet self, const EthernetSocket sock)
+{
+    if (self != NULL && sock != NULL && sock->rawSocket != -1) {
+        FD_SET(sock->rawSocket, &self->handles);
+        if (sock->rawSocket > self->maxHandle) {
+            self->maxHandle = sock->rawSocket;
+        }
+    }
+}
+
+int
+EthernetHandleSet_waitReady(EthernetHandleSet self, unsigned int timeoutMs)
+{
+    int result;
+
+    if ((self != NULL) && (self->maxHandle >= 0)) {
+        struct timeval timeout;
+
+        timeout.tv_sec = timeoutMs / 1000;
+        timeout.tv_usec = (timeoutMs % 1000) * 1000;
+        result = select(self->maxHandle + 1, &self->handles, NULL, NULL, &timeout);
+    }
+    else {
+       result = -1;
+    }
+
+    return result;
+}
+
+void
+EthernetHandleSet_destroy(EthernetHandleSet self)
+{
+    GLOBAL_FREEMEM(self);
+}
+
 static int
 getInterfaceIndex(int sock, const char* deviceName)
 {

src/hal/inc/hal_ethernet.h

@@ -48,6 +48,50 @@ extern "C" {
  */
 typedef struct sEthernetSocket* EthernetSocket;
 
+/** Opaque reference for a set of ethernet socket handles */
+typedef struct sEthernetHandleSet* EthernetHandleSet;
+
+/**
+ * \brief Create a new connection handle set (EthernetHandleSet)
+ *
+ * \return new EthernetHandleSet instance
+ */
+EthernetHandleSet
+EthernetHandleSet_new(void);
+
+/**
+ * \brief add a socket to an existing handle set
+ *
+ * \param self the HandleSet instance
+ * \param sock the socket to add
+ */
+void
+EthernetHandleSet_addSocket(EthernetHandleSet self, const EthernetSocket sock);
+
+
+/**
+ * \brief wait for a socket to become ready
+ *
+ * This function is corresponding to the BSD socket select function.
+ * It returns the number of sockets on which data is pending or 0 if no data is pending
+ * on any of the monitored connections. The function will return after "timeout" ms if no
+ * data is pending.
+ * The function shall return -1 if a socket error occures.
+ *
+ *  \param self the EthernetHandleSet instance
+ *  \param timeout in milliseconds (ms)
+ */
+int
+EthernetHandleSet_waitReady(EthernetHandleSet self, unsigned int timeoutMs);
+
+/**
+ * \brief destroy the EthernetHandleSet instance
+ *
+ * \param self the HandleSet instance to destroy
+ */
+void
+EthernetHandleSet_destroy(EthernetHandleSet self);
+
 /**
  * \brief Return the MAC address of an Ethernet interface.
  *