include/net/netfilter/nf_conntrack_protocol.h

   1 /*
   2  * Header for use in defining a given 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_PROTOCOL_H
  11 #define _NF_CONNTRACK_PROTOCOL_H
  12 #include <net/netfilter/nf_conntrack.h>
  13
  14 struct seq_file;
  15 struct nfattr;
  16
  17 struct nf_conntrack_protocol
  18 {
  19         /* Next pointer. */
  20         struct list_head list;
  21
  22         /* L3 Protocol number. */
  23         u_int16_t l3proto;
  24
  25         /* Protocol number. */
  26         u_int8_t proto;
  27
  28         /* Protocol name */
  29         const char *name;
  30
  31         /* Try to fill in the third arg: dataoff is offset past network protocol
  32            hdr.  Return true if possible. */
  33         int (*pkt_to_tuple)(const struct sk_buff *skb,
  34                             unsigned int dataoff,
  35                             struct nf_conntrack_tuple *tuple);
  36
  37         /* Invert the per-proto part of the tuple: ie. turn xmit into reply.
  38          * Some packets can't be inverted: return 0 in that case.
  39          */
  40         int (*invert_tuple)(struct nf_conntrack_tuple *inverse,
  41                             const struct nf_conntrack_tuple *orig);
  42
  43         /* Print out the per-protocol part of the tuple. Return like seq_* */
  44         int (*print_tuple)(struct seq_file *s,
  45                            const struct nf_conntrack_tuple *);
  46
  47         /* Print out the private part of the conntrack. */
  48         int (*print_conntrack)(struct seq_file *s, const struct nf_conn *);
  49
  50         /* Returns verdict for packet, or -1 for invalid. */
  51         int (*packet)(struct nf_conn *conntrack,
  52                       const struct sk_buff *skb,
  53                       unsigned int dataoff,
  54                       enum ip_conntrack_info ctinfo,
  55                       int pf,
  56                       unsigned int hooknum);
  57
  58         /* Called when a new connection for this protocol found;
  59          * returns TRUE if it's OK.  If so, packet() called next. */
  60         int (*new)(struct nf_conn *conntrack, const struct sk_buff *skb,
  61                    unsigned int dataoff);
  62
  63         /* Called when a conntrack entry is destroyed */
  64         void (*destroy)(struct nf_conn *conntrack);
  65
  66         int (*error)(struct sk_buff *skb, unsigned int dataoff,
  67                      enum ip_conntrack_info *ctinfo,
  68                      int pf, unsigned int hooknum);
  69
  70         /* convert protoinfo to nfnetink attributes */
  71         int (*to_nfattr)(struct sk_buff *skb, struct nfattr *nfa,
  72                          const struct nf_conn *ct);
  73
  74         /* convert nfnetlink attributes to protoinfo */
  75         int (*from_nfattr)(struct nfattr *tb[], struct nf_conn *ct);
  76
  77         int (*tuple_to_nfattr)(struct sk_buff *skb,
  78                                const struct nf_conntrack_tuple *t);
  79         int (*nfattr_to_tuple)(struct nfattr *tb[],
  80                                struct nf_conntrack_tuple *t);
  81
  82         /* Module (if any) which this is connected to. */
  83         struct module *me;
  84 };
  85
  86 /* Existing built-in protocols */
  87 extern struct nf_conntrack_protocol nf_conntrack_protocol_tcp6;
  88 extern struct nf_conntrack_protocol nf_conntrack_protocol_udp4;
  89 extern struct nf_conntrack_protocol nf_conntrack_protocol_udp6;
  90 extern struct nf_conntrack_protocol nf_conntrack_generic_protocol;
  91
  92 #define MAX_NF_CT_PROTO 256
  93 extern struct nf_conntrack_protocol **nf_ct_protos[PF_MAX];
  94
  95 extern struct nf_conntrack_protocol *
  96 __nf_ct_proto_find(u_int16_t l3proto, u_int8_t protocol);
  97
  98 extern struct nf_conntrack_protocol *
  99 nf_ct_proto_find_get(u_int16_t l3proto, u_int8_t protocol);
 100
 101 extern void nf_ct_proto_put(struct nf_conntrack_protocol *p);
 102
 103 /* Protocol registration. */
 104 extern int nf_conntrack_protocol_register(struct nf_conntrack_protocol *proto);
 105 extern void nf_conntrack_protocol_unregister(struct nf_conntrack_protocol *proto);
 106
 107 /* Generic netlink helpers */
 108 extern int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb,
 109                                       const struct nf_conntrack_tuple *tuple);
 110 extern int nf_ct_port_nfattr_to_tuple(struct nfattr *tb[],
 111                                       struct nf_conntrack_tuple *t);
 112
 113 /* Log invalid packets */
 114 extern unsigned int nf_ct_log_invalid;
 115
 116 #ifdef CONFIG_SYSCTL
 117 #ifdef DEBUG_INVALID_PACKETS
 118 #define LOG_INVALID(proto) \
 119         (nf_ct_log_invalid == (proto) || nf_ct_log_invalid == IPPROTO_RAW)
 120 #else
 121 #define LOG_INVALID(proto) \
 122         ((nf_ct_log_invalid == (proto) || nf_ct_log_invalid == IPPROTO_RAW) \
 123          && net_ratelimit())
 124 #endif
 125 #else
 126 #define LOG_INVALID(proto) 0
 127 #endif /* CONFIG_SYSCTL */
 128
 129 #endif /*_NF_CONNTRACK_PROTOCOL_H*/