[PATCH] discover: Recognise renamed network interfaces

[Samuel Mendoza-Jonas]

Udev may change the name of network interfaces if persistent interface
naming is used. It is important to recognise this since udev may re-use
the old name for a different interface.
If we receive an RTM_NEWLINK message for an existing interface, check if
the name has been updated.

Signed-off-by: Samuel Mendoza-Jonas <sam.mj at au1.ibm.com>
---
 discover/network.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/discover/network.c b/discover/network.c
index 3946694..0dad087 100644
--- a/discover/network.c
+++ b/discover/network.c
@@ -510,6 +510,15 @@ static int network_handle_nlmsg(struct network *network, struct nlmsghdr *nlmsg)
 		add_interface(network, interface);
 	}
 
+	/* A repeated RTM_NEWLINK can represent an interface name change */
+	if (strncmp(interface->name, ifname, IFNAMSIZ)) {
+		pb_debug("ifname update: %s -> %s\n", interface->name, ifname);
+		strncpy(interface->name, ifname, sizeof(interface->name) - 1);
+		talloc_free(interface->dev->device->id);
+		interface->dev->device->id =
+			talloc_strdup(interface->dev->device, ifname);
+	}
+
 	/* notify the sysinfo code about changes to this interface */
 	if (strcmp(interface->name, "lo"))
 		system_info_register_interface(
-- 
2.1.0