1 files changed, 89 insertions, 0 deletions
diff --git a/include/net/netfilter/nf_synproxy.h b/include/net/netfilter/nf_synproxy.h
new file mode 100644
index 000000000..a336f9434
--- /dev/null
+++ b/include/net/netfilter/nf_synproxy.h
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _NF_SYNPROXY_SHARED_H
+#define _NF_SYNPROXY_SHARED_H
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <net/ip6_checksum.h>
+#include <net/ip6_route.h>
+#include <net/tcp.h>
+
+#include <net/netfilter/nf_conntrack_seqadj.h>
+#include <net/netfilter/nf_conntrack_synproxy.h>
+
+struct synproxy_stats {
+	unsigned int			syn_received;
+	unsigned int			cookie_invalid;
+	unsigned int			cookie_valid;
+	unsigned int			cookie_retrans;
+	unsigned int			conn_reopened;
+};
+
+struct synproxy_net {
+	struct nf_conn			*tmpl;
+	struct synproxy_stats __percpu	*stats;
+	unsigned int			hook_ref4;
+	unsigned int			hook_ref6;
+};
+
+extern unsigned int synproxy_net_id;
+static inline struct synproxy_net *synproxy_pernet(struct net *net)
+{
+	return net_generic(net, synproxy_net_id);
+}
+
+struct synproxy_options {
+	u8				options;
+	u8				wscale;
+	u16				mss_option;
+	u16				mss_encode;
+	u32				tsval;
+	u32				tsecr;
+};
+
+struct nf_synproxy_info;
+bool synproxy_parse_options(const struct sk_buff *skb, unsigned int doff,
+			    const struct tcphdr *th,
+			    struct synproxy_options *opts);
+
+void synproxy_init_timestamp_cookie(const struct nf_synproxy_info *info,
+				    struct synproxy_options *opts);
+
+void synproxy_send_client_synack(struct net *net, const struct sk_buff *skb,
+				 const struct tcphdr *th,
+				 const struct synproxy_options *opts);
+
+bool synproxy_recv_client_ack(struct net *net,
+			      const struct sk_buff *skb,
+			      const struct tcphdr *th,
+			      struct synproxy_options *opts, u32 recv_seq);
+
+struct nf_hook_state;
+
+unsigned int ipv4_synproxy_hook(void *priv, struct sk_buff *skb,
+				const struct nf_hook_state *nhs);
+int nf_synproxy_ipv4_init(struct synproxy_net *snet, struct net *net);
+void nf_synproxy_ipv4_fini(struct synproxy_net *snet, struct net *net);
+
+#if IS_ENABLED(CONFIG_IPV6)
+void synproxy_send_client_synack_ipv6(struct net *net,
+				      const struct sk_buff *skb,
+				      const struct tcphdr *th,
+				      const struct synproxy_options *opts);
+
+bool synproxy_recv_client_ack_ipv6(struct net *net, const struct sk_buff *skb,
+				   const struct tcphdr *th,
+				   struct synproxy_options *opts, u32 recv_seq);
+
+unsigned int ipv6_synproxy_hook(void *priv, struct sk_buff *skb,
+				const struct nf_hook_state *nhs);
+int nf_synproxy_ipv6_init(struct synproxy_net *snet, struct net *net);
+void nf_synproxy_ipv6_fini(struct synproxy_net *snet, struct net *net);
+#else
+static inline int
+nf_synproxy_ipv6_init(struct synproxy_net *snet, struct net *net) { return 0; }
+static inline void
+nf_synproxy_ipv6_fini(struct synproxy_net *snet, struct net *net) {};
+#endif /* CONFIG_IPV6 */
+
+#endif /* _NF_SYNPROXY_SHARED_H */