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/netfilter/nf_conntrack.h>
  14
  15 struct seq_file;
  16
  17 struct nf_conntrack_l4proto
  18 {
  19         /* L3 Protocol number. */
  20         u_int16_t l3proto;
  21
  22         /* L4 Protocol number. */
  23         u_int8_t l4proto;
  24
  25         /* Protocol name */
  26         const char *name;
  27
  28         /* Try to fill in the third arg: dataoff is offset past network protocol
  29            hdr.  Return true if possible. */
  30         int (*pkt_to_tuple)(const struct sk_buff *skb,
  31                             unsigned int dataoff,
  32                             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         int (*invert_tuple)(struct nf_conntrack_tuple *inverse,
  38                             const struct nf_conntrack_tuple *orig);
  39
  40         /* Print out the per-protocol part of the tuple. Return like seq_* */
  41         int (*print_tuple)(struct seq_file *s,
  42                            const struct nf_conntrack_tuple *);
  43
  44         /* Print out the private part of the conntrack. */
  45         int (*print_conntrack)(struct seq_file *s, const struct nf_conn *);
  46
  47         /* Returns verdict for packet, or -1 for invalid. */
  48         int (*packet)(struct nf_conn *conntrack,
  49                       const struct sk_buff *skb,
  50                       unsigned int dataoff,
  51                       enum ip_conntrack_info ctinfo,
  52                       int pf,
  53                       unsigned int hooknum);
  54
  55         /* Called when a new connection for this protocol found;
  56          * returns TRUE if it's OK.  If so, packet() called next. */
  57         int (*new)(struct nf_conn *conntrack, const struct sk_buff *skb,
  58                    unsigned int dataoff);
  59
  60         /* Called when a conntrack entry is destroyed */
  61         void (*destroy)(struct nf_conn *conntrack);
  62
  63         int (*error)(struct sk_buff *skb, unsigned int dataoff,
  64                      enum ip_conntrack_info *ctinfo,
  65                      int pf, unsigned int hooknum);
  66
  67         /* convert protoinfo to nfnetink attributes */
  68         int (*to_nfattr)(struct sk_buff *skb, struct nlattr *nla,
  69                          const struct nf_conn *ct);
  70
  71         /* convert nfnetlink attributes to protoinfo */
  72         int (*from_nfattr)(struct nlattr *tb[], struct nf_conn *ct);
  73
  74         int (*tuple_to_nfattr)(struct sk_buff *skb,
  75                                const struct nf_conntrack_tuple *t);
  76         int (*nfattr_to_tuple)(struct nlattr *tb[],
  77                                struct nf_conntrack_tuple *t);
  78
  79 #ifdef CONFIG_SYSCTL
  80         struct ctl_table_header **ctl_table_header;
  81         struct ctl_table        *ctl_table;
  82         unsigned int            *ctl_table_users;
  83 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
  84         struct ctl_table_header *ctl_compat_table_header;
  85         struct ctl_table        *ctl_compat_table;
  86 #endif
  87 #endif
  88
  89         /* Module (if any) which this is connected to. */
  90         struct module *me;
  91 };
  92
  93 /* Existing built-in protocols */
  94 extern struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp6;
  95 extern struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4;
  96 extern struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6;
  97 extern struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
  98
  99 #define MAX_NF_CT_PROTO 256
 100
 101 extern struct nf_conntrack_l4proto *
 102 __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto);
 103
 104 extern struct nf_conntrack_l4proto *
 105 nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t protocol);
 106
 107 extern void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p);
 108
 109 /* Protocol registration. */
 110 extern int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *proto);
 111 extern void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *proto);
 112
 113 /* Generic netlink helpers */
 114 extern int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb,
 115                                       const struct nf_conntrack_tuple *tuple);
 116 extern int nf_ct_port_nfattr_to_tuple(struct nlattr *tb[],
 117                                       struct nf_conntrack_tuple *t);
 118
 119 /* Log invalid packets */
 120 extern unsigned int nf_ct_log_invalid;
 121
 122 #ifdef CONFIG_SYSCTL
 123 #ifdef DEBUG_INVALID_PACKETS
 124 #define LOG_INVALID(proto) \
 125         (nf_ct_log_invalid == (proto) || nf_ct_log_invalid == IPPROTO_RAW)
 126 #else
 127 #define LOG_INVALID(proto) \
 128         ((nf_ct_log_invalid == (proto) || nf_ct_log_invalid == IPPROTO_RAW) \
 129          && net_ratelimit())
 130 #endif
 131 #else
 132 #define LOG_INVALID(proto) 0
 133 #endif /* CONFIG_SYSCTL */
 134
 135 #endif /*_NF_CONNTRACK_PROTOCOL_H*/