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