include/net/netfilter/nf_conntrack_synproxy.h

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