ax25: add link layer header validation function
As variable length protocol, AX25 fails link layer header validation
tests based on a minimum length. header_ops.validate allows protocols
to validate headers that are shorter than hard_header_len. Implement
this callback for AX25.
See also http://comments.gmane.org/gmane.linux.network/401064
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ax25/ax25_ip.c b/net/ax25/ax25_ip.c
index b563a3f..2fa3be9 100644
--- a/net/ax25/ax25_ip.c
+++ b/net/ax25/ax25_ip.c
@@ -228,8 +228,23 @@
}
#endif
+static bool ax25_validate_header(const char *header, unsigned int len)
+{
+ ax25_digi digi;
+
+ if (!len)
+ return false;
+
+ if (header[0])
+ return true;
+
+ return ax25_addr_parse(header + 1, len - 1, NULL, NULL, &digi, NULL,
+ NULL);
+}
+
const struct header_ops ax25_header_ops = {
.create = ax25_hard_header,
+ .validate = ax25_validate_header,
};
EXPORT_SYMBOL(ax25_header_ops);