nf_nat_l4proto.h

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/* Header for use in defining a given protocol. */
#ifndef _NF_NAT_L4PROTO_H
#define _NF_NAT_L4PROTO_H
#include <net/netfilter/nf_nat.h>
#include <linux/netfilter/nfnetlink_conntrack.h>

struct nf_nat_range;
struct nf_nat_l3proto;

struct nf_nat_l4proto {
    /* Protocol number. */
    u8 l4proto;

    /* Translate a packet to the target according to manip type.
     * Return true if succeeded.
     */
    bool (*manip_pkt)(struct sk_buff *skb,
              const struct nf_nat_l3proto *l3proto,
              unsigned int iphdroff, unsigned int hdroff,
              const struct nf_conntrack_tuple *tuple,
              enum nf_nat_manip_type maniptype);

    /* Is the manipable part of the tuple between min and max incl? */
    bool (*in_range)(const struct nf_conntrack_tuple *tuple,
             enum nf_nat_manip_type maniptype,
             const union nf_conntrack_man_proto *min,
             const union nf_conntrack_man_proto *max);

    /* Alter the per-proto part of the tuple (depending on
     * maniptype), to give a unique tuple in the given range if
     * possible.  Per-protocol part of tuple is initialized to the
     * incoming packet.
     */
    void (*unique_tuple)(const struct nf_nat_l3proto *l3proto,
                 struct nf_conntrack_tuple *tuple,
                 const struct nf_nat_range *range,
                 enum nf_nat_manip_type maniptype,
                 const struct nf_conn *ct);

    int (*nlattr_to_range)(struct nlattr *tb[],
                   struct nf_nat_range *range);
};

/* Protocol registration. */
extern int nf_nat_l4proto_register(u8 l3proto, const struct nf_nat_l4proto *l4proto);
extern void nf_nat_l4proto_unregister(u8 l3proto, const struct nf_nat_l4proto *l4proto);

extern const struct nf_nat_l4proto *__nf_nat_l4proto_find(u8 l3proto, u8 l4proto);

/* Built-in protocols. */
extern const struct nf_nat_l4proto nf_nat_l4proto_tcp;
extern const struct nf_nat_l4proto nf_nat_l4proto_udp;
extern const struct nf_nat_l4proto nf_nat_l4proto_icmp;
extern const struct nf_nat_l4proto nf_nat_l4proto_icmpv6;
extern const struct nf_nat_l4proto nf_nat_l4proto_unknown;

extern bool nf_nat_l4proto_in_range(const struct nf_conntrack_tuple *tuple,
                    enum nf_nat_manip_type maniptype,
                    const union nf_conntrack_man_proto *min,
                    const union nf_conntrack_man_proto *max);

extern void nf_nat_l4proto_unique_tuple(const struct nf_nat_l3proto *l3proto,
                    struct nf_conntrack_tuple *tuple,
                    const struct nf_nat_range *range,
                    enum nf_nat_manip_type maniptype,
                    const struct nf_conn *ct,
                    u16 *rover);

extern int nf_nat_l4proto_nlattr_to_range(struct nlattr *tb[],
                      struct nf_nat_range *range);

#endif /*_NF_NAT_L4PROTO_H*/