LXR linux/include/net/netfilter/nf_conntrack

   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
  16struct seq_file;
  17
  18struct nf_conntrack_l4proto
  19{
  20        /* L3 Protocol number. */
  21        u_int16_t l3proto;
  22
  23        /* L4 Protocol number. */
  24        u_int8_t l4proto;
  25
  26        /* Try to fill in the third arg: dataoff is offset past network protocol
  27           hdr.  Return true if possible. */
  28        bool (*pkt_to_tuple)(const struct sk_buff *skb, unsigned int dataoff,
  29                             struct nf_conntrack_tuple *tuple);
  30
  31        /* Invert the per-proto part of the tuple: ie. turn xmit into reply.
  32         * Some packets can't be inverted: return 0 in that case.
  33         */
  34        bool (*invert_tuple)(struct nf_conntrack_tuple *inverse,
  35                             const struct nf_conntrack_tuple *orig);
  36
  37        /* Returns verdict for packet, or -1 for invalid. */
  38        int (*packet)(struct nf_conn *ct,
  39                      const struct sk_buff *skb,
  40                      unsigned int dataoff,
  41                      enum ip_conntrack_info ctinfo,
  42                      u_int8_t pf,
  43                      unsigned int hooknum);
  44
  45        /* Called when a new connection for this protocol found;
  46         * returns TRUE if it's OK.  If so, packet() called next. */
  47        bool (*new)(struct nf_conn *ct, const struct sk_buff *skb,
  48                    unsigned int dataoff);
  49
  50        /* Called when a conntrack entry is destroyed */
  51        void (*destroy)(struct nf_conn *ct);
  52
  53        int (*error)(struct net *net, struct sk_buff *skb, unsigned int dataoff,
  54                     enum ip_conntrack_info *ctinfo,
  55                     u_int8_t pf, unsigned int hooknum);
  56
  57        /* Print out the per-protocol part of the tuple. Return like seq_* */
  58        int (*print_tuple)(struct seq_file *s,
  59                           const struct nf_conntrack_tuple *);
  60
  61        /* Print out the private part of the conntrack. */
  62        int (*print_conntrack)(struct seq_file *s, const struct nf_conn *);
  63
  64        /* convert protoinfo to nfnetink attributes */
  65        int (*to_nlattr)(struct sk_buff *skb, struct nlattr *nla,
  66                         const struct nf_conn *ct);
  67
  68        /* convert nfnetlink attributes to protoinfo */
  69        int (*from_nlattr)(struct nlattr *tb[], struct nf_conn *ct);
  70
  71        int (*tuple_to_nlattr)(struct sk_buff *skb,
  72                               const struct nf_conntrack_tuple *t);
  73        int (*nlattr_to_tuple)(struct nlattr *tb[],
  74                               struct nf_conntrack_tuple *t);
  75        const struct nla_policy *nla_policy;
  76
  77#ifdef CONFIG_SYSCTL
  78        struct ctl_table_header **ctl_table_header;
  79        struct ctl_table        *ctl_table;
  80        unsigned int            *ctl_table_users;
  81#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
  82        struct ctl_table_header *ctl_compat_table_header;
  83        struct ctl_table        *ctl_compat_table;
  84#endif
  85#endif
  86        /* Protocol name */
  87        const char *name;
  88
  89        /* Module (if any) which this is connected to. */
  90        struct module *me;
  91};
  92
  93/* Existing built-in protocols */
  94extern struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp6;
  95extern struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4;
  96extern struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6;
  97extern struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
  98
  99#define MAX_NF_CT_PROTO 256
 100
 101extern struct nf_conntrack_l4proto *
 102__nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto);
 103
 104extern struct nf_conntrack_l4proto *
 105nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t protocol);
 106
 107extern void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p);
 108
 109/* Protocol registration. */
 110extern int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *proto);
 111extern void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *proto);
 112
 113/* Generic netlink helpers */
 114extern int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 115                                      const struct nf_conntrack_tuple *tuple);
 116extern int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 117                                      struct nf_conntrack_tuple *t);
 118extern const struct nla_policy nf_ct_port_nla_policy[];
 119
 120#ifdef CONFIG_SYSCTL
 121#ifdef DEBUG_INVALID_PACKETS
 122#define LOG_INVALID(net, proto)                         \
 123        ((net)->ct.sysctl_log_invalid == (proto) ||     \
 124         (net)->ct.sysctl_log_invalid == IPPROTO_RAW)
 125#else
 126#define LOG_INVALID(net, proto)                         \
 127        (((net)->ct.sysctl_log_invalid == (proto) ||    \
 128          (net)->ct.sysctl_log_invalid == IPPROTO_RAW)  \
 129         && net_ratelimit())
 130#endif
 131#else
 132#define LOG_INVALID(net, proto) 0
 133#endif /* CONFIG_SYSCTL */
 134
 135#endif /*_NF_CONNTRACK_PROTOCOL_H*/
 136