bgpd: ignore 4 bits of attribute flags byte
diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c
index aa4ce8f..45a17fa 100644
--- a/bgpd/bgp_attr.c
+++ b/bgpd/bgp_attr.c
@@ -1788,7 +1788,10 @@
/* Fetch attribute flag and type. */
startp = BGP_INPUT_PNT (peer);
- flag = stream_getc (BGP_INPUT (peer));
+ /* "The lower-order four bits of the Attribute Flags octet are
+ unused. They MUST be zero when sent and MUST be ignored when
+ received." */
+ flag = 0xF0 & stream_getc (BGP_INPUT (peer));
type = stream_getc (BGP_INPUT (peer));
/* Check whether Extended-Length applies and is in bounds */