discover: Recognise renamed network interfaces

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@au1.ibm.com>

diff --git a/discover/network.c b/discover/network.c
index 3946694615fd4d931352610fd8abbafafd8a8264..0dad087bb4199a3d2ed15510bad1f0b43cc1f1ab 100644 (file)
--- 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(