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
  16 struct seq_file;
  17
  18 struct 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         /* Protocol name */
  27         const char *name;
  28
  29         /* Try to fill in the third arg: dataoff is offset past network protocol
  30            hdr.  Return true if possible. */
  31         int (*pkt_to_tuple)(const struct sk_buff *skb,
  32                             unsigned int dataoff,
  33                             struct nf_conntrack_tuple *tuple);
  34
  35         /* Invert the per-proto part of the tuple: ie. turn xmit into reply.
  36          * Some packets can't be inverted: return 0 in that case.
  37          */
  38         int (*invert_tuple)(struct nf_conntrack_tuple *inverse,
  39                             const struct nf_conntrack_tuple *orig);
  40
  41         /* Print out the per-protocol part of the tuple. Return like seq_* */
  42         int (*print_tuple)(struct seq_file *s,
  43                            const struct nf_conntrack_tuple *);
  44
  45         /* Print out the private part of the conntrack. */
  46         int (*print_conntrack)(struct seq_file *s, const struct nf_conn *);
  47
  48         /* Returns verdict for packet, or -1 for invalid. */
  49         int (*packet)(struct nf_conn *conntrack,
  50                       const struct sk_buff *skb,
  51                       unsigned int dataoff,
  52                       enum ip_conntrack_info ctinfo,
  53                       int pf,
  54                       unsigned int hooknum);
  55
  56         /* Called when a new connection for this protocol found;
  57          * returns TRUE if it's OK.  If so, packet() called next. */
  58         int (*new)(struct nf_conn *conntrack, const struct sk_buff *skb,
  59                    unsigned int dataoff);
  60
  61         /* Called when a conntrack entry is destroyed */
  62         void (*destroy)(struct nf_conn *conntrack);
  63
  64         int (*error)(struct sk_buff *skb, unsigned int dataoff,
  65                      enum ip_conntrack_info *ctinfo,
  66                      int pf, unsigned int hooknum);
  67
  68         /* convert protoinfo to nfnetink attributes */
  69         int (*to_nlattr)(struct sk_buff *skb, struct nlattr *nla,
  70                          const struct nf_conn *ct);
  71
  72         /* convert nfnetlink attributes to protoinfo */
  73         int (*from_nlattr)(struct nlattr *tb[], struct nf_conn *ct);
  74
  75         int (*tuple_to_nlattr)(struct sk_buff *skb,
  76                                const struct nf_conntrack_tuple *t);
  77         int (*nlattr_to_tuple)(struct nlattr *tb[],
  78                                struct nf_conntrack_tuple *t);
  79         const struct nla_policy *nla_policy;
  80
  81 #ifdef CONFIG_SYSCTL
  82         struct ctl_table_header **ctl_table_header;
  83         struct ctl_table        *ctl_table;
  84         unsigned int            *ctl_table_users;
  85 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
  86         struct ctl_table_header *ctl_compat_table_header;
  87         struct ctl_table        *ctl_compat_table;
  88 #endif
  89 #endif
  90
  91         /* Module (if any) which this is connected to. */
  92         struct module *me;
  93 };
  94
  95 /* Existing built-in protocols */
  96 extern struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp6;
  97 extern struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4;
  98 extern struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6;
  99 extern struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
 100
 101 #define MAX_NF_CT_PROTO 256
 102
 103 extern struct nf_conntrack_l4proto *
 104 __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto);
 105
 106 extern struct nf_conntrack_l4proto *
 107 nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t protocol);
 108
 109 extern void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p);
 110
 111 /* Protocol registration. */
 112 extern int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *proto);
 113 extern void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *proto);
 114
 115 /* Generic netlink helpers */
 116 extern int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 117                                       const struct nf_conntrack_tuple *tuple);
 118 extern int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 119                                       struct nf_conntrack_tuple *t);
 120 extern const struct nla_policy nf_ct_port_nla_policy[];
 121
 122 /* Log invalid packets */
 123 extern unsigned int nf_ct_log_invalid;
 124
 125 #ifdef CONFIG_SYSCTL
 126 #ifdef DEBUG_INVALID_PACKETS
 127 #define LOG_INVALID(proto) \
 128         (nf_ct_log_invalid == (proto) || nf_ct_log_invalid == IPPROTO_RAW)
 129 #else
 130 #define LOG_INVALID(proto) \
 131         ((nf_ct_log_invalid == (proto) || nf_ct_log_invalid == IPPROTO_RAW) \
 132          && net_ratelimit())
 133 #endif
 134 #else
 135 #define LOG_INVALID(proto) 0
 136 #endif /* CONFIG_SYSCTL */
 137
 138 #endif /*_NF_CONNTRACK_PROTOCOL_H*/