mpls: Prevent use of implicit NULL label as outgoing label

The reserved implicit-NULL label isn't allowed to appear in the label
stack for packets, so make it an error for the control plane to
specify it as an outgoing label.

Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Robert Shearman 2015-04-22 11:14:39 +01:00 committed by David S. Miller
parent 37bde79979
commit 5a9ab01761
1 changed files with 9 additions and 0 deletions

View File

@ -646,6 +646,15 @@ int nla_get_labels(const struct nlattr *nla,
if ((dec.bos != bos) || dec.ttl || dec.tc)
return -EINVAL;
switch (dec.label) {
case LABEL_IMPLICIT_NULL:
/* RFC3032: This is a label that an LSR may
* assign and distribute, but which never
* actually appears in the encapsulation.
*/
return -EINVAL;
}
label[i] = dec.label;
}
*labels = nla_labels;