attr: Allow attribute type 0

{netlink,packet,unix}_diag use attribute type 0 for valid
attributes. The value was reserved and usage was prohibited
by the protocol but we can't undo the breakge.

Make libnl accept attribute type 0 to allow parsing these
attributes.

Reported-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>

diff --git a/lib/attr.c b/lib/attr.c
index 535f10ca2bd4685e6aee60f3f3a9b8df1e54e203..e83aca2c196a5c5bf100e953189dffa09e8bb2a0 100644 (file)
--- a/lib/attr.c
+++ b/lib/attr.c
@@ -192,7 +192,7 @@ static int validate_nla(struct nlattr *nla, int maxtype,
        unsigned int minlen = 0;
        int type = nla_type(nla);
 
-       if (type <= 0 || type > maxtype)
+       if (type < 0 || type > maxtype)
                return 0;
 
        pt = &policy[type];