+/* Call this before modifying an existing packet: ensures it is
+ modifiable and linear to the point you care about (writable_len).
+ Returns true or false. */
+extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len);
+
+struct nf_afinfo {
+ unsigned short family;
+ unsigned int (*checksum)(struct sk_buff *skb, unsigned int hook,
+ unsigned int dataoff, u_int8_t protocol);
+ void (*saveroute)(const struct sk_buff *skb,
+ struct nf_info *info);
+ int (*reroute)(struct sk_buff **skb,
+ const struct nf_info *info);
+ int route_key_size;
+};
+
+extern struct nf_afinfo *nf_afinfo[];
+static inline struct nf_afinfo *nf_get_afinfo(unsigned short family)
+{
+ return rcu_dereference(nf_afinfo[family]);
+}
+
+static inline unsigned int
+nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
+ u_int8_t protocol, unsigned short family)
+{
+ struct nf_afinfo *afinfo;
+ unsigned int csum = 0;
+
+ rcu_read_lock();
+ afinfo = nf_get_afinfo(family);
+ if (afinfo)
+ csum = afinfo->checksum(skb, hook, dataoff, protocol);
+ rcu_read_unlock();
+ return csum;
+}
+
+extern int nf_register_afinfo(struct nf_afinfo *afinfo);
+extern void nf_unregister_afinfo(struct nf_afinfo *afinfo);
+
+#define nf_info_reroute(x) ((void *)x + sizeof(struct nf_info))
+
+#include <net/flow.h>
+extern void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *);
+
+static inline void
+nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family)
+{
+#ifdef CONFIG_IP_NF_NAT_NEEDED
+ void (*decodefn)(struct sk_buff *, struct flowi *);
+
+ if (family == AF_INET && (decodefn = ip_nat_decode_session) != NULL)
+ decodefn(skb, fl);
+#endif
+}
+
+#ifdef CONFIG_PROC_FS
+#include <linux/proc_fs.h>
+extern struct proc_dir_entry *proc_net_netfilter;
+#endif
+