[PATCH 2/2] discover/network: Ensure interfaces have device before configuring

[Samuel Mendoza-Jonas]

Reorganise network_handle_nlmsg() slightly to create interface->dev just
before calling configure_interface() rather than only for brand new
interfaces. This ensures existing interfaces which have had ->dev
removed but receive a new configure event do not access a NULL pointer
during the configuration process.

Signed-off-by: Samuel Mendoza-Jonas <sam at mendozajonas.com>
---
 discover/network.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/discover/network.c b/discover/network.c
index c3cf30a..6ae4417 100644
--- a/discover/network.c
+++ b/discover/network.c
@@ -214,13 +214,12 @@ static int network_send_link_query(struct network *network)
 	return 0;
 }
 
-static void add_interface(struct network *network,
+static void create_interface_dev(struct network *network,
 		struct interface *interface)
 {
 	char *uuid = mac_bytes_to_string(interface, interface->hwaddr,
 						sizeof(interface->hwaddr));
 
-	list_add(&network->interfaces, &interface->list);
 	interface->dev = discover_device_create(network->handler, uuid,
 						interface->name);
 	interface->dev->device->type = DEVICE_TYPE_NETWORK;
@@ -563,7 +562,8 @@ static int network_handle_nlmsg(struct network *network, struct nlmsghdr *nlmsg)
 		interface->state = IFSTATE_NEW;
 		memcpy(interface->hwaddr, ifaddr, sizeof(interface->hwaddr));
 		strncpy(interface->name, ifname, sizeof(interface->name) - 1);
-		add_interface(network, interface);
+		list_add(&network->interfaces, &interface->list);
+		create_interface_dev(network, interface);
 	}
 
 	/* A repeated RTM_NEWLINK can represent an interface name change */
@@ -582,6 +582,9 @@ static int network_handle_nlmsg(struct network *network, struct nlmsghdr *nlmsg)
 				interface->hwaddr, interface->name,
 				info->ifi_flags & IFF_LOWER_UP);
 
+	if (!interface->dev)
+		create_interface_dev(network, interface);
+
 	configure_interface(network, interface,
 			info->ifi_flags & IFF_UP,
 			info->ifi_flags & IFF_LOWER_UP);
-- 
2.11.0