include/net/netfilter/nf_conntrack_l4proto.h

   1 /*
   2  * Header for use in defining a given L4 protocol for connection tracking.
   3  *
   4  * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
   5  *      - generalized L3 protocol dependent part.
   6  *
   7  * Derived from include/linux/netfiter_ipv4/ip_conntrack_protcol.h
   8  */
   9
  10 #ifndef _NF_CONNTRACK_L4PROTO_H
  11 #define _NF_CONNTRACK_L4PROTO_H
  12 #include <linux/netlink.h>
  13 #include <net/netlink.h>
  14 #include <net/netfilter/nf_conntrack.h>
  15 #include <net/netns/generic.h>
  16
  17 struct seq_file;
  18
  19 struct nf_conntrack_l4proto {
  20         /* L3 Protocol number. */
  21         u_int16_t l3proto;
  22
  23         /* L4 Protocol number. */
  24         u_int8_t l4proto;
  25
  26         /* Resolve clashes on insertion races. */
  27         bool allow_clash;
  28
  29         /* Try to fill in the third arg: dataoff is offset past network protocol
  30            hdr.  Return true if possible. */
  31         bool (*pkt_to_tuple)(const struct sk_buff *skb, unsigned int dataoff,
  32                              struct net *net, struct nf_conntrack_tuple *tuple);
  33
  34         /* Invert the per-proto part of the tuple: ie. turn xmit into reply.
  35          * Some packets can't be inverted: return 0 in that case.
  36          */
  37         bool (*invert_tuple)(struct nf_conntrack_tuple *inverse,
  38                              const struct nf_conntrack_tuple *orig);
  39
  40         /* Returns verdict for packet, or -1 for invalid. */
  41         int (*packet)(struct nf_conn *ct,
  42                       const struct sk_buff *skb,
  43                       unsigned int dataoff,
  44                       enum ip_conntrack_info ctinfo,
  45                       u_int8_t pf,
  46                       unsigned int hooknum,
  47                       unsigned int *timeouts);
  48
  49         /* Called when a new connection for this protocol found;
  50          * returns TRUE if it's OK.  If so, packet() called next. */
  51         bool (*new)(struct nf_conn *ct, const struct sk_buff *skb,
  52                     unsigned int dataoff, unsigned int *timeouts);
  53
  54         /* Called when a conntrack entry is destroyed */
  55         void (*destroy)(struct nf_conn *ct);
  56
  57         int (*error)(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
  58                      unsigned int dataoff, enum ip_conntrack_info *ctinfo,
  59                      u_int8_t pf, unsigned int hooknum);
  60
  61         /* Print out the per-protocol part of the tuple. Return like seq_* */
  62         void (*print_tuple)(struct seq_file *s,
  63                             const struct nf_conntrack_tuple *);
  64
  65         /* Print out the private part of the conntrack. */
  66         void (*print_conntrack)(struct seq_file *s, struct nf_conn *);
  67
  68         /* Return the array of timeouts for this protocol. */
  69         unsigned int *(*get_timeouts)(struct net *net);
  70
  71         /* convert protoinfo to nfnetink attributes */
  72         int (*to_nlattr)(struct sk_buff *skb, struct nlattr *nla,
  73                          struct nf_conn *ct);
  74         /* Calculate protoinfo nlattr size */
  75         int (*nlattr_size)(void);
  76
  77         /* convert nfnetlink attributes to protoinfo */
  78         int (*from_nlattr)(struct nlattr *tb[], struct nf_conn *ct);
  79
  80         int (*tuple_to_nlattr)(struct sk_buff *skb,
  81                                const struct nf_conntrack_tuple *t);
  82         /* Calculate tuple nlattr size */
  83         int (*nlattr_tuple_size)(void);
  84         int (*nlattr_to_tuple)(struct nlattr *tb[],
  85                                struct nf_conntrack_tuple *t);
  86         const struct nla_policy *nla_policy;
  87
  88         size_t nla_size;
  89
  90 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
  91         struct {
  92                 size_t obj_size;
  93                 int (*nlattr_to_obj)(struct nlattr *tb[],
  94                                      struct net *net, void *data);
  95                 int (*obj_to_nlattr)(struct sk_buff *skb, const void *data);
  96
  97                 unsigned int nlattr_max;
  98                 const struct nla_policy *nla_policy;
  99         } ctnl_timeout;
 100 #endif
 101         unsigned int    *net_id;
 102         /* Init l4proto pernet data */
 103         int (*init_net)(struct net *net, u_int16_t proto);
 104
 105         /* Return the per-net protocol part. */
 106         struct nf_proto_net *(*get_net_proto)(struct net *net);
 107
 108         /* Protocol name */
 109         const char *name;
 110
 111         /* Module (if any) which this is connected to. */
 112         struct module *me;
 113 };
 114
 115 /* Existing built-in generic protocol */
 116 extern struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
 117
 118 #define MAX_NF_CT_PROTO 256
 119
 120 struct nf_conntrack_l4proto *__nf_ct_l4proto_find(u_int16_t l3proto,
 121                                                   u_int8_t l4proto);
 122
 123 struct nf_conntrack_l4proto *nf_ct_l4proto_find_get(u_int16_t l3proto,
 124                                                     u_int8_t l4proto);
 125 void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p);
 126
 127 /* Protocol pernet registration. */
 128 int nf_ct_l4proto_pernet_register_one(struct net *net,
 129                                       struct nf_conntrack_l4proto *proto);
 130 void nf_ct_l4proto_pernet_unregister_one(struct net *net,
 131                                          struct nf_conntrack_l4proto *proto);
 132 int nf_ct_l4proto_pernet_register(struct net *net,
 133                                   struct nf_conntrack_l4proto *proto[],
 134                                   unsigned int num_proto);
 135 void nf_ct_l4proto_pernet_unregister(struct net *net,
 136                                      struct nf_conntrack_l4proto *proto[],
 137                                      unsigned int num_proto);
 138
 139 /* Protocol global registration. */
 140 int nf_ct_l4proto_register_one(struct nf_conntrack_l4proto *proto);
 141 void nf_ct_l4proto_unregister_one(struct nf_conntrack_l4proto *proto);
 142 int nf_ct_l4proto_register(struct nf_conntrack_l4proto *proto[],
 143                            unsigned int num_proto);
 144 void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *proto[],
 145                               unsigned int num_proto);
 146
 147 /* Generic netlink helpers */
 148 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 149                                const struct nf_conntrack_tuple *tuple);
 150 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 151                                struct nf_conntrack_tuple *t);
 152 int nf_ct_port_nlattr_tuple_size(void);
 153 extern const struct nla_policy nf_ct_port_nla_policy[];
 154
 155 #ifdef CONFIG_SYSCTL
 156 #define LOG_INVALID(net, proto)                         \
 157         ((net)->ct.sysctl_log_invalid == (proto) ||     \
 158          (net)->ct.sysctl_log_invalid == IPPROTO_RAW)
 159 #else
 160 static inline int LOG_INVALID(struct net *net, int proto) { return 0; }
 161 #endif /* CONFIG_SYSCTL */
 162
 163 #endif /*_NF_CONNTRACK_PROTOCOL_H*/