1 files changed, 113 insertions, 0 deletions
diff --git a/python-ethtool/netlink.c b/python-ethtool/netlink.c
new file mode 100644
index 0000000..f80ebd4
--- /dev/null
+++ b/python-ethtool/netlink.c
@@ -0,0 +1,113 @@
+/* netlink.c - Generic NETLINK API functions
+ *
+ * Copyright (C) 2009-2013 Red Hat Inc.
+ *
+ * David Sommerseth <davids@redhat.com>
+ *
+ * This application is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; version 2.
+ *
+ * This application is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <Python.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <netlink/netlink.h>
+#include <netlink/socket.h>
+
+#include "etherinfo_struct.h"
+
+pthread_mutex_t nlc_counter_mtx = PTHREAD_MUTEX_INITIALIZER;
+
+
+/**
+ * Connects to the NETLINK interface.  This will be called
+ * for each etherinfo object being generated, and it will
+ * keep a separate file descriptor open for each object
+ *
+ * @param data etherinfo_obj_data structure
+ *
+ * @return Returns 1 on success, otherwise 0.
+ */
+int open_netlink(struct etherinfo_obj_data *data)
+{
+	if( !data ) {
+		return 0;
+	}
+
+	/* Reuse already established NETLINK connection, if a connection exists */
+	if( *data->nlc ) {
+		/* If this object has not used NETLINK earlier, tag it as a user */
+		if( !data->nlc_active ) {
+			pthread_mutex_lock(&nlc_counter_mtx);
+			(*data->nlc_users)++;
+			pthread_mutex_unlock(&nlc_counter_mtx);
+		}
+		data->nlc_active = 1;
+		return 1;
+	}
+
+	/* No earlier connections exists, establish a new one */
+	*data->nlc = nl_socket_alloc();
+	nl_connect(*data->nlc, NETLINK_ROUTE);
+	if( (*data->nlc != NULL) ) {
+		/* Force O_CLOEXEC flag on the NETLINK socket */
+		if( fcntl(nl_socket_get_fd(*data->nlc), F_SETFD, FD_CLOEXEC) == -1 ) {
+			fprintf(stderr,
+				"**WARNING** Failed to set O_CLOEXEC on NETLINK socket: %s\n",
+				strerror(errno));
+		}
+
+		/* Tag this object as an active user */
+		pthread_mutex_lock(&nlc_counter_mtx);
+		(*data->nlc_users)++;
+		pthread_mutex_unlock(&nlc_counter_mtx);
+		data->nlc_active = 1;
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
+
+/**
+ * Closes the NETLINK connection.  This should be called automatically whenever
+ * the corresponding etherinfo object is deleted.
+ *
+ * @param ptr  Pointer to the pointer of struct nl_handle, which contains the NETLINK connection
+ */
+void close_netlink(struct etherinfo_obj_data *data)
+{
+	if( !data || !(*data->nlc) ) {
+		return;
+	}
+
+	/* Untag this object as a NETLINK user */
+	data->nlc_active = 0;
+	pthread_mutex_lock(&nlc_counter_mtx);
+	(*data->nlc_users)--;
+	pthread_mutex_unlock(&nlc_counter_mtx);
+
+	/* Don't close the connection if there are more users */
+	if( *data->nlc_users > 0) {
+		return;
+	}
+
+	/* Close NETLINK connection */
+	nl_close(*data->nlc);
+	nl_socket_free(*data->nlc);
+	*data->nlc = NULL;
+}
+
+/*
+Local variables:
+c-basic-offset: 8
+indent-tabs-mode: y
+End:
+*/