include/net/netfilter/nf_conntrack_synproxy.h

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