[Openvpn-devel] [PATCH] Implement --passtos for tagged ethernet frames

[David S. <ope...@to...>]

From: Davide Guerri <dg...@us...>

This patch makes it possible to use the --passtos option with 802.1Q tagged
ethernet frames.

sf.net tracker:
<https://sourceforge.net/tracker/?func=detail&aid=2829878&group_id=48978&atid=454721>

Signed-off-by: David Sommerseth <da...@us...>
---
 proto.c |   14 +++++++++++---
 proto.h |   12 ++++++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/proto.c b/proto.c
index 72a3c6b..1f582ce 100644
--- a/proto.c
+++ b/proto.c
@@ -53,9 +53,17 @@ is_ipv4 (int tunnel_type, struct buffer *buf)
 	  + sizeof (struct openvpn_iphdr)))
 	return false;
       eh = (const struct openvpn_ethhdr *) BPTR (buf);
-      if (ntohs (eh->proto) != OPENVPN_ETH_P_IPV4)
-	return false;
-      offset = sizeof (struct openvpn_ethhdr);
+      if (ntohs (eh->proto) == OPENVPN_ETH_P_8021Q) {
+        const struct openvpn_8021qhdr *evh;
+        evh = (const struct openvpn_8021qhdr *) BPTR (buf);
+        if (ntohs (evh->proto) != OPENVPN_ETH_P_IPV4)
+          return false;
+        else
+          offset = sizeof (struct openvpn_8021qhdr);
+      } else if (ntohs (eh->proto) != OPENVPN_ETH_P_IPV4)
+        return false;
+      else
+        offset = sizeof (struct openvpn_ethhdr);
     }
   else
     return false;
diff --git a/proto.h b/proto.h
index f26fc8c..628e991 100644
--- a/proto.h
+++ b/proto.h
@@ -64,6 +64,18 @@ struct openvpn_ethhdr
   uint16_t proto;                     /* packet type ID field */
 };
 
+# define OPENVPN_ETH_P_8021Q  0x8100  /* 802.1Q protocol */
+
+struct openvpn_8021qhdr
+{
+  uint8_t dest[OPENVPN_ETH_ALEN];     /* destination ethernet addr */
+  uint8_t source[OPENVPN_ETH_ALEN];   /* source ethernet addr	*/
+
+  uint32_t tag;                       /* packet 802.1Q Vlan Tag */
+  uint16_t proto;                     /* packet type ID field */
+};
+
+
 struct openvpn_arp {
 # define ARP_MAC_ADDR_TYPE 0x0001
   uint16_t mac_addr_type;       /* 0x0001 */
-- 
1.6.6.1