[PATCH iproute2] ip route: restore_handler should check tb[RTA_PREFSRC] for local networks

Prior to this patch, If one route entry's RTA_PREFSRC and RTA_GATEWAY
both were NULL, it was supposed to be restored ONLY as a local address.

But as it didn't check tb[RTA_PREFSRC] when restoring local networks,
rtattr_cmp would return a success if it was NULL, this route entry would
be restored again as a local network.

This patch is to add tb[RTA_PREFSRC] check when restoring local networks.

Fixes: 74af8dd9620e ("ip route: restore route entries in correct order")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 ip/iproute.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ip/iproute.c b/ip/iproute.c
index c52294d..3da23af 100644
--- a/ip/iproute.c
+++ b/ip/iproute.c

@@ -1813,7 +1813,7 @@ static int restore_handler(const struct sockaddr_nl *nl,
 	if (!prio && !tb[RTA_GATEWAY] && (!tb[RTA_PREFSRC] ||
 	    !rtattr_cmp(tb[RTA_PREFSRC], tb[RTA_DST])))
 		goto restore;
-	else if (prio == 1 && !tb[RTA_GATEWAY] &&
+	else if (prio == 1 && !tb[RTA_GATEWAY] && tb[RTA_PREFSRC] &&
 		 rtattr_cmp(tb[RTA_PREFSRC], tb[RTA_DST]))
 		goto restore;
 	else if (prio == 2 && tb[RTA_GATEWAY])

-- 
2.1.0

On Sun, Aug 07, 2016 at 05:12:30PM +0800, Xin Long wrote:

Prior to this patch, If one route entry's RTA_PREFSRC and RTA_GATEWAY
both were NULL, it was supposed to be restored ONLY as a local address.

But as it didn't check tb[RTA_PREFSRC] when restoring local networks,
rtattr_cmp would return a success if it was NULL, this route entry would
be restored again as a local network.

This patch is to add tb[RTA_PREFSRC] check when restoring local networks.

Fixes: 74af8dd9620e ("ip route: restore route entries in correct order")
Signed-off-by: Xin Long <lucien.xin@gmail.com>

Tested-by: Phil Sutter <phil@nwl.cc>

Hi, Stephen

any update on this ?

On Wed, 17 Aug 2016 11:32:53 +0800
Xin Long [off-list ref] wrote:

Hi, Stephen

any update on this ?

Was waiting long enough to get a comment or two.

On Sun,  7 Aug 2016 17:12:30 +0800
Xin Long [off-list ref] wrote:

Prior to this patch, If one route entry's RTA_PREFSRC and RTA_GATEWAY
both were NULL, it was supposed to be restored ONLY as a local address.

But as it didn't check tb[RTA_PREFSRC] when restoring local networks,
rtattr_cmp would return a success if it was NULL, this route entry would
be restored again as a local network.

This patch is to add tb[RTA_PREFSRC] check when restoring local networks.

Fixes: 74af8dd9620e ("ip route: restore route entries in correct order")
Signed-off-by: Xin Long <lucien.xin@gmail.com>

Applied