root/include/net/netfilter/nf_conntrack_l4proto.h

INCLUDED FROM

/*
 * Header for use in defining a given L4 protocol for connection tracking.
 *
 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
 *      - generalized L3 protocol dependent part.
 *
 * Derived from include/linux/netfiter_ipv4/ip_conntrack_protcol.h
 */

#ifndef _NF_CONNTRACK_L4PROTO_H
#define _NF_CONNTRACK_L4PROTO_H
#include <linux/netlink.h>
#include <net/netlink.h>
#include <net/netfilter/nf_conntrack.h>

struct seq_file;

struct nf_conntrack_l4proto
{
        /* L3 Protocol number. */
        u_int16_t l3proto;

        /* L4 Protocol number. */
        u_int8_t l4proto;

        /* Try to fill in the third arg: dataoff is offset past network protocol
           hdr.  Return true if possible. */
        bool (*pkt_to_tuple)(const struct sk_buff *skb, unsigned int dataoff,
                             struct nf_conntrack_tuple *tuple);

        /* Invert the per-proto part of the tuple: ie. turn xmit into reply.
         * Some packets can't be inverted: return 0 in that case.
         */
        bool (*invert_tuple)(struct nf_conntrack_tuple *inverse,
                             const struct nf_conntrack_tuple *orig);

        /* Returns verdict for packet, or -1 for invalid. */
        int (*packet)(struct nf_conn *ct,
                      const struct sk_buff *skb,
                      unsigned int dataoff,
                      enum ip_conntrack_info ctinfo,
                      u_int8_t pf,
                      unsigned int hooknum);

        /* Called when a new connection for this protocol found;
         * returns TRUE if it's OK.  If so, packet() called next. */
        bool (*new)(struct nf_conn *ct, const struct sk_buff *skb,
                    unsigned int dataoff);

        /* Called when a conntrack entry is destroyed */
        void (*destroy)(struct nf_conn *ct);

        int (*error)(struct net *net, struct sk_buff *skb, unsigned int dataoff,
                     enum ip_conntrack_info *ctinfo,
                     u_int8_t pf, unsigned int hooknum);

        /* Print out the per-protocol part of the tuple. Return like seq_* */
        int (*print_tuple)(struct seq_file *s,
                           const struct nf_conntrack_tuple *);

        /* Print out the private part of the conntrack. */
        int (*print_conntrack)(struct seq_file *s, const struct nf_conn *);

        /* convert protoinfo to nfnetink attributes */
        int (*to_nlattr)(struct sk_buff *skb, struct nlattr *nla,
                         const struct nf_conn *ct);

        /* convert nfnetlink attributes to protoinfo */
        int (*from_nlattr)(struct nlattr *tb[], struct nf_conn *ct);

        int (*tuple_to_nlattr)(struct sk_buff *skb,
                               const struct nf_conntrack_tuple *t);
        int (*nlattr_to_tuple)(struct nlattr *tb[],
                               struct nf_conntrack_tuple *t);
        const struct nla_policy *nla_policy;

#ifdef CONFIG_SYSCTL
        struct ctl_table_header **ctl_table_header;
        struct ctl_table        *ctl_table;
        unsigned int            *ctl_table_users;
#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
        struct ctl_table_header *ctl_compat_table_header;
        struct ctl_table        *ctl_compat_table;
#endif
#endif
        /* Protocol name */
        const char *name;

        /* Module (if any) which this is connected to. */
        struct module *me;
};

/* Existing built-in protocols */
extern struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp6;
extern struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4;
extern struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6;
extern struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;

#define MAX_NF_CT_PROTO 256

extern struct nf_conntrack_l4proto *
__nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto);

extern struct nf_conntrack_l4proto *
nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t protocol);

extern void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p);

/* Protocol registration. */
extern int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *proto);
extern void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *proto);

/* Generic netlink helpers */
extern int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
                                      const struct nf_conntrack_tuple *tuple);
extern int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
                                      struct nf_conntrack_tuple *t);
extern const struct nla_policy nf_ct_port_nla_policy[];

#ifdef CONFIG_SYSCTL
#ifdef DEBUG_INVALID_PACKETS
#define LOG_INVALID(net, proto)                         \
        ((net)->ct.sysctl_log_invalid == (proto) ||     \
         (net)->ct.sysctl_log_invalid == IPPROTO_RAW)
#else
#define LOG_INVALID(net, proto)                         \
        (((net)->ct.sysctl_log_invalid == (proto) ||    \
          (net)->ct.sysctl_log_invalid == IPPROTO_RAW)  \
         && net_ratelimit())
#endif
#else
#define LOG_INVALID(net, proto) 0
#endif /* CONFIG_SYSCTL */

#endif /*_NF_CONNTRACK_PROTOCOL_H*/