MFS: recognize gre packets used in the WCCP protocol.

Approved by:	re

sys/net/if_gre.h

@@ -104,6 +104,13 @@ struct greip {
 #define GRE_SP		0x1000  /* Sequence Present */
 #define GRE_SS		0x0800	/* Strict Source Route */
 
+/*
+ * CISCO uses special type for GRE tunnel created as part of WCCP
+ * connection, while in fact those packets are just IPv4 encapsulated
+ * into GRE.
+ */
+#define WCCP_PROTOCOL_TYPE	0x883E
+
 /*
  * gre_sre defines a Source route Entry. These are needed if packets
  * should be routed over more than one tunnel hop by hop

sys/netinet/ip_gre.c

@@ -179,7 +179,8 @@ gre_input2(struct mbuf *m ,int hlen, u_char proto)
 
 		switch (ntohs(gip->gi_ptype)) { /* ethertypes */
 		case ETHERTYPE_IP: /* shouldn't need a schednetisr(), as */
-			ifq = &ipintrq;          /* we are in ip_input */
+		case WCCP_PROTOCOL_TYPE: /* we are in ip_input */
+			ifq = &ipintrq;
 			break;
 #ifdef NS
 		case ETHERTYPE_NS: