1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _NF_CONNTRACK_SYNPROXY_H
3 #define _NF_CONNTRACK_SYNPROXY_H
4
5 #include <net/netns/generic.h>
6
7 struct nf_conn_synproxy {
8 u32 isn;
9 u32 its;
10 u32 tsoff;
11 };
12
nfct_synproxy(const struct nf_conn * ct)13 static inline struct nf_conn_synproxy *nfct_synproxy(const struct nf_conn *ct)
14 {
15 #if IS_ENABLED(CONFIG_NETFILTER_SYNPROXY)
16 return nf_ct_ext_find(ct, NF_CT_EXT_SYNPROXY);
17 #else
18 return NULL;
19 #endif
20 }
21
nfct_synproxy_ext_add(struct nf_conn * ct)22 static inline struct nf_conn_synproxy *nfct_synproxy_ext_add(struct nf_conn *ct)
23 {
24 #if IS_ENABLED(CONFIG_NETFILTER_SYNPROXY)
25 return nf_ct_ext_add(ct, NF_CT_EXT_SYNPROXY, GFP_ATOMIC);
26 #else
27 return NULL;
28 #endif
29 }
30
nf_ct_add_synproxy(struct nf_conn * ct,const struct nf_conn * tmpl)31 static inline bool nf_ct_add_synproxy(struct nf_conn *ct,
32 const struct nf_conn *tmpl)
33 {
34 if (tmpl && nfct_synproxy(tmpl)) {
35 if (!nfct_seqadj_ext_add(ct))
36 return false;
37
38 if (!nfct_synproxy_ext_add(ct))
39 return false;
40 }
41
42 return true;
43 }
44
45 struct synproxy_stats {
46 unsigned int syn_received;
47 unsigned int cookie_invalid;
48 unsigned int cookie_valid;
49 unsigned int cookie_retrans;
50 unsigned int conn_reopened;
51 };
52
53 struct synproxy_net {
54 struct nf_conn *tmpl;
55 struct synproxy_stats __percpu *stats;
56 unsigned int hook_ref4;
57 unsigned int hook_ref6;
58 };
59
60 extern unsigned int synproxy_net_id;
synproxy_pernet(struct net * net)61 static inline struct synproxy_net *synproxy_pernet(struct net *net)
62 {
63 return net_generic(net, synproxy_net_id);
64 }
65
66 struct synproxy_options {
67 u8 options;
68 u8 wscale;
69 u16 mss;
70 u32 tsval;
71 u32 tsecr;
72 };
73
74 struct tcphdr;
75 struct xt_synproxy_info;
76 bool synproxy_parse_options(const struct sk_buff *skb, unsigned int doff,
77 const struct tcphdr *th,
78 struct synproxy_options *opts);
79 unsigned int synproxy_options_size(const struct synproxy_options *opts);
80 void synproxy_build_options(struct tcphdr *th,
81 const struct synproxy_options *opts);
82
83 void synproxy_init_timestamp_cookie(const struct xt_synproxy_info *info,
84 struct synproxy_options *opts);
85 void synproxy_check_timestamp_cookie(struct synproxy_options *opts);
86
87 unsigned int synproxy_tstamp_adjust(struct sk_buff *skb, unsigned int protoff,
88 struct tcphdr *th, struct nf_conn *ct,
89 enum ip_conntrack_info ctinfo,
90 const struct nf_conn_synproxy *synproxy);
91
92 #endif /* _NF_CONNTRACK_SYNPROXY_H */
93