1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _NF_SYNPROXY_SHARED_H
3#define _NF_SYNPROXY_SHARED_H
4
5#include <linux/module.h>
6#include <linux/skbuff.h>
7#include <net/ip6_checksum.h>
8#include <net/ip6_route.h>
9#include <net/tcp.h>
10
11#include <net/netfilter/nf_conntrack_seqadj.h>
12#include <net/netfilter/nf_conntrack_synproxy.h>
13
14struct synproxy_stats {
15	unsigned int			syn_received;
16	unsigned int			cookie_invalid;
17	unsigned int			cookie_valid;
18	unsigned int			cookie_retrans;
19	unsigned int			conn_reopened;
20};
21
22struct synproxy_net {
23	struct nf_conn			*tmpl;
24	struct synproxy_stats __percpu	*stats;
25	unsigned int			hook_ref4;
26	unsigned int			hook_ref6;
27};
28
29extern unsigned int synproxy_net_id;
30static inline struct synproxy_net *synproxy_pernet(struct net *net)
31{
32	return net_generic(net, synproxy_net_id);
33}
34
35struct synproxy_options {
36	u8				options;
37	u8				wscale;
38	u16				mss_option;
39	u16				mss_encode;
40	u32				tsval;
41	u32				tsecr;
42};
43
44struct nf_synproxy_info;
45bool synproxy_parse_options(const struct sk_buff *skb, unsigned int doff,
46			    const struct tcphdr *th,
47			    struct synproxy_options *opts);
48
49void synproxy_init_timestamp_cookie(const struct nf_synproxy_info *info,
50				    struct synproxy_options *opts);
51
52void synproxy_send_client_synack(struct net *net, const struct sk_buff *skb,
53				 const struct tcphdr *th,
54				 const struct synproxy_options *opts);
55
56bool synproxy_recv_client_ack(struct net *net,
57			      const struct sk_buff *skb,
58			      const struct tcphdr *th,
59			      struct synproxy_options *opts, u32 recv_seq);
60
61struct nf_hook_state;
62
63unsigned int ipv4_synproxy_hook(void *priv, struct sk_buff *skb,
64				const struct nf_hook_state *nhs);
65int nf_synproxy_ipv4_init(struct synproxy_net *snet, struct net *net);
66void nf_synproxy_ipv4_fini(struct synproxy_net *snet, struct net *net);
67
68#if IS_ENABLED(CONFIG_IPV6)
69void synproxy_send_client_synack_ipv6(struct net *net,
70				      const struct sk_buff *skb,
71				      const struct tcphdr *th,
72				      const struct synproxy_options *opts);
73
74bool synproxy_recv_client_ack_ipv6(struct net *net, const struct sk_buff *skb,
75				   const struct tcphdr *th,
76				   struct synproxy_options *opts, u32 recv_seq);
77
78unsigned int ipv6_synproxy_hook(void *priv, struct sk_buff *skb,
79				const struct nf_hook_state *nhs);
80int nf_synproxy_ipv6_init(struct synproxy_net *snet, struct net *net);
81void nf_synproxy_ipv6_fini(struct synproxy_net *snet, struct net *net);
82#else
83static inline int
84nf_synproxy_ipv6_init(struct synproxy_net *snet, struct net *net) { return 0; }
85static inline void
86nf_synproxy_ipv6_fini(struct synproxy_net *snet, struct net *net) {};
87#endif /* CONFIG_IPV6 */
88
89#endif /* _NF_SYNPROXY_SHARED_H */
90