Split out the link info from get_etherinfo()

This is a needed step for the next move, where we'll
query the interfaces for IP address at as late as possible.

Signed-off-by: David Sommerseth <davids@redhat.com>

Author: David Sommerseth

python-ethtool/etherinfo.c

@@ -125,32 +125,108 @@ static void callback_nl_address(struct nl_object *obj, void *arg)
 }
 
 
+/**
+ * Sets the etherinfo.index member to the corresponding device set in etherinfo.device
+ *
+ * @param ethinf A pointer a struct etherinfo element which contains the device name
+ *               and a place to save the corresponding index value.
+ *
+ * @return Returns 1 on success, otherwise 0.
+ */
+static int _set_device_index(struct etherinfo *ethinf)
+{
+	struct nl_cache *link_cache;
+	struct rtnl_link *link;
+
+	/* Find the interface index we're looking up.
+	 * As we don't expect it to change, we're reusing a "cached"
+	 * interface index if we have that
+	 */
+	if( ethinf->index < 0 ) {
+		if( rtnl_link_alloc_cache(get_nlc(), AF_UNSPEC, &link_cache) < 0) {
+                        return 0;
+                }
+
+                link = rtnl_link_get_by_name(link_cache, ethinf->device);
+                if( !link ) {
+			nl_cache_free(link_cache);
+                        return 0;
+                }
+
+		ethinf->index = rtnl_link_get_ifindex(link);
+		if( ethinf->index < 0 ) {
+			rtnl_link_put(link);
+			nl_cache_free(link_cache);
+			return 0;
+		}
+		rtnl_link_put(link);
+		nl_cache_free(link_cache);
+	}
+        return 1;
+}
+
 
 /*
  *
  *   Exported functions - API frontend
  *
  */
 
+int get_etherinfo_link(etherinfo_py *self)
+{
+	struct nl_cache *link_cache;
+	struct rtnl_link *link;
+	struct etherinfo *ethinf = NULL;
+
+	if( !self || !self->ethinfo ) {
+		return 0;
+	}
+	ethinf = self->ethinfo;
+
+	/* Open a NETLINK connection on-the-fly */
+	if( !open_netlink(self) ) {
+		PyErr_Format(PyExc_RuntimeError,
+			     "Could not open a NETLINK connection for %s",
+			     ethinf->device);
+		return 0;
+	}
+
+        if( _set_device_index(ethinf) != 1) {
+                return 0;
+        }
+
+        /* Extract MAC/hardware address of the interface */
+        if( rtnl_link_alloc_cache(get_nlc(), AF_UNSPEC, &link_cache) < 0) {
+                return 0;
+        }
+        link = rtnl_link_alloc();
+        /* FIXME: Error handling? */
+        rtnl_link_set_ifindex(link, ethinf->index);
+        nl_cache_foreach_filter(link_cache, OBJ_CAST(link), callback_nl_link, ethinf);
+        rtnl_link_put(link);
+        nl_cache_free(link_cache);
+
+        return 1;
+}
+
+
+
 /**
- * Query NETLINK for ethernet configuration
+ * Query NETLINK for device IP address configuration
  *
  * @param ethinf Pointer to an available struct etherinfo element.  The 'device' member
  *               must contain a valid string to the device to query for information
  * @param nlc    Pointer to the libnl handle, which is used for the query against NETLINK
- * @param query  What to query for.  Must be NLQRY_LINK or NLQRY_ADDR.
+ * @param query  What to query for.  Must be NLQRY_ADDR4 or NLQRY_ADDR6.
  *
  * @return Returns 1 on success, otherwise 0.
  */
 int get_etherinfo(etherinfo_py *self, nlQuery query)
 {
-	struct nl_cache *link_cache;
 	struct nl_cache *addr_cache;
 	struct rtnl_addr *addr;
-	struct rtnl_link *link;
 	struct etherinfo *ethinf = NULL;
         PyObject *addrlist = NULL;
-
 	int ret = 0;
 
 	if( !self || !self->ethinfo ) {
@@ -166,46 +242,12 @@ int get_etherinfo(etherinfo_py *self, nlQuery query)
 		return 0;
 	}
 
-	/* Find the interface index we're looking up.
-	 * As we don't expect it to change, we're reusing a "cached"
-	 * interface index if we have that
-	 */
-	if( ethinf->index < 0 ) {
-		if( rtnl_link_alloc_cache(get_nlc(), AF_UNSPEC, &link_cache) < 0) {
-                        return 0;
-                }
-
-                link = rtnl_link_get_by_name(link_cache, ethinf->device);
-                if( !link ) {
-			nl_cache_free(link_cache);
-                        return 0;
-                }
-
-		ethinf->index = rtnl_link_get_ifindex(link);
-		if( ethinf->index < 0 ) {
-			rtnl_link_put(link);
-			nl_cache_free(link_cache);
-			return 0;
-		}
-		rtnl_link_put(link);
-		nl_cache_free(link_cache);
-	}
+        if( _set_device_index(ethinf) != 1) {
+                return 0;
+        }
 
 	/* Query the for requested info vai NETLINK */
 	switch( query ) {
-	case NLQRY_LINK:
-		/* Extract MAC/hardware address of the interface */
-		if( rtnl_link_alloc_cache(get_nlc(), AF_UNSPEC, &link_cache) < 0) {
-                        return 0;
-                }
-		link = rtnl_link_alloc();
-		rtnl_link_set_ifindex(link, ethinf->index);
-		nl_cache_foreach_filter(link_cache, OBJ_CAST(link), callback_nl_link, ethinf);
-		rtnl_link_put(link);
-		nl_cache_free(link_cache);
-		ret = 1;
-		break;
-
         case NLQRY_ADDR4:
         case NLQRY_ADDR6:
 		/* Extract IP address information */

python-ethtool/etherinfo.h

@@ -19,6 +19,7 @@
 
 typedef enum {NLQRY_LINK, NLQRY_ADDR4, NLQRY_ADDR6} nlQuery; /**<  Supported query types in the etherinfo code */
 
+int get_etherinfo_link(etherinfo_py *data);
 int get_etherinfo(etherinfo_py *data, nlQuery query);
 void free_etherinfo(struct etherinfo *ptr);
 

python-ethtool/etherinfo_obj.c

@@ -147,7 +147,7 @@ PyObject *_ethtool_etherinfo_getter(etherinfo_py *self, PyObject *attr_o)
                         return Py_INCREF(Py_None), Py_None;
                 }
 	} else if( strcmp(attr, "mac_address") == 0 ) {
-		get_etherinfo(self, NLQRY_LINK);
+		get_etherinfo_link(self);
 		Py_INCREF(self->ethinfo->hwaddress);
 		return self->ethinfo->hwaddress;
 	} else if( strcmp(attr, "ipv4_address") == 0 ) {
@@ -216,7 +216,7 @@ PyObject *_ethtool_etherinfo_str(etherinfo_py *self)
 		return NULL;
 	}
 
-	get_etherinfo(self, NLQRY_LINK);
+	get_etherinfo_link(self);
 	get_etherinfo(self, NLQRY_ADDR4);
 	get_etherinfo(self, NLQRY_ADDR6);