This patch changes buf_filter_incoming_vlan_tags() to use a less nested
code-style. It also improves documentation of the function.
In addition, the function is made static, as it is only used locally.
Code based on a snippet by Peter Stuge.
Signed-off-by: Fabian Knittel <fabian.knit...@avona.com>
---
multi.c | 39 ++++++++++++++++++++++++---------------
1 files changed, 24 insertions(+), 15 deletions(-)
diff --git a/multi.c b/multi.c
index 1a8bbbf..83c5aa3 100644
--- a/multi.c
+++ b/multi.c
@@ -1925,24 +1925,33 @@ multi_process_post (struct multi_context *m, struct
multi_instance *mi, const un
}
#ifdef ENABLE_VLAN_TAGGING
-bool
+/*
+ * Decides whether or not to drop an ethernet frame. VLAN-tagged frames are
+ * dropped. All other frames are accepted.
+ *
+ * @param buf The ethernet frame.
+ * @return Returns true if the frame should be dropped, false otherwise.
+ */
+static bool
buf_filter_incoming_vlan_tags (const struct buffer *buf)
{
- if (BLEN (buf) >= (int) sizeof (struct openvpn_8021qhdr))
- {
- const struct openvpn_8021qhdr *vlanhdr = (const struct openvpn_8021qhdr
*) BPTR (buf);
+ const struct openvpn_8021qhdr *vlanhdr;
+ uint16_t vid;
- if (ntohs (vlanhdr->tpid) == OPENVPN_ETH_P_8021Q)
- {
- const uint16_t vid = vlanhdr_get_vid(vlanhdr);
- if (vid != 0)
- {
- msg (D_VLAN_DEBUG, "dropping tagged incoming frame, vid: %u",
vid);
- return true;
- }
- }
- }
- return false;
+ if (BLEN (buf) < (int) sizeof (struct openvpn_8021qhdr))
+ return false; /* Frame too small. */
+
+ vlanhdr = (const struct openvpn_8021qhdr *) BPTR (buf);
+
+ if (ntohs (vlanhdr->tpid) != OPENVPN_ETH_P_8021Q)
+ return false; /* Frame is untagged. */
+
+ vid = vlanhdr_get_vid(vlanhdr);
+ if (vid == 0)
+ return false; /* Frame only priority-tagged. */
+
+ msg (D_VLAN_DEBUG, "dropping VLAN-tagged incoming frame, vid: %u", vid);
+ return true;
}
#endif
--
1.7.0
