Verify in fwd_port_input() that we are not passed packets that are shared.

datapath/forward.c

@@ -68,6 +68,7 @@ int run_flow_through_tables(struct sw_chain *chain, struct sk_buff *skb,
 void fwd_port_input(struct sw_chain *chain, struct sk_buff *skb,
 		    struct net_bridge_port *p)
 {
+	WARN_ON_ONCE(skb_shared(skb));
 	if (run_flow_through_tables(chain, skb, p))
 		dp_output_control(chain->dp, skb, fwd_save_skb(skb), 
 				  chain->dp->miss_send_len,

datapath/linux-2.4/compat-2.4/include/asm/bug.h

@@ -0,0 +1,17 @@
+#ifndef _ASM_GENERIC_BUG_H
+#define _ASM_GENERIC_BUG_H
+
+#include <linux/compiler.h>
+
+#define WARN_ON_ONCE(condition)	({				\
+	static int __warned;					\
+	int __ret_warn_once = !!(condition);			\
+								\
+	if (unlikely(__ret_warn_once) && !__warned) {		\
+		WARN_ON(1);					\
+		__warned = 1;					\
+	}							\
+	unlikely(__ret_warn_once);				\
+})
+
+#endif

datapath/linux-2.4/compat-2.4/include/linux/kernel.h

@@ -3,6 +3,7 @@
 
 #include_next <linux/kernel.h>
 #include <linux/config.h>
+#include <asm/bug.h>
 
 /**
  * container_of - cast a member of a structure out to the containing structure