include/net/netfilter/nf_synproxy.h

   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
  14 struct 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
  22 struct 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
  29 extern unsigned int synproxy_net_id;
  30 static inline struct synproxy_net *synproxy_pernet(struct net *net)
  31 {
  32         return net_generic(net, synproxy_net_id);
  33 }
  34
  35 struct synproxy_options {
  36         u8                              options;
  37         u8                              wscale;
  38         u16                             mss_option;
  39         u16                             mss_encode;
  40         u32                             tsval;
  41         u32                             tsecr;
  42 };
  43
  44 struct nf_synproxy_info;
  45 bool synproxy_parse_options(const struct sk_buff *skb, unsigned int doff,
  46                             const struct tcphdr *th,
  47                             struct synproxy_options *opts);
  48
  49 void synproxy_init_timestamp_cookie(const struct nf_synproxy_info *info,
  50                                     struct synproxy_options *opts);
  51
  52 void synproxy_send_client_synack(struct net *net, const struct sk_buff *skb,
  53                                  const struct tcphdr *th,
  54                                  const struct synproxy_options *opts);
  55
  56 bool 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
  61 struct nf_hook_state;
  62
  63 unsigned int ipv4_synproxy_hook(void *priv, struct sk_buff *skb,
  64                                 const struct nf_hook_state *nhs);
  65 int nf_synproxy_ipv4_init(struct synproxy_net *snet, struct net *net);
  66 void nf_synproxy_ipv4_fini(struct synproxy_net *snet, struct net *net);
  67
  68 #if IS_ENABLED(CONFIG_IPV6)
  69 void 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
  74 bool 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
  78 unsigned int ipv6_synproxy_hook(void *priv, struct sk_buff *skb,
  79                                 const struct nf_hook_state *nhs);
  80 int nf_synproxy_ipv6_init(struct synproxy_net *snet, struct net *net);
  81 void nf_synproxy_ipv6_fini(struct synproxy_net *snet, struct net *net);
  82 #else
  83 static inline int
  84 nf_synproxy_ipv6_init(struct synproxy_net *snet, struct net *net) { return 0; }
  85 static inline void
  86 nf_synproxy_ipv6_fini(struct synproxy_net *snet, struct net *net) {};
  87 #endif /* CONFIG_IPV6 */
  88
  89 #endif /* _NF_SYNPROXY_SHARED_H */