include/linux/netfilter_ipv4/ip_conntrack_protocol.h

   1 /* Header for use in defining a given protocol for connection tracking. */
   2 #ifndef _IP_CONNTRACK_PROTOCOL_H
   3 #define _IP_CONNTRACK_PROTOCOL_H
   4 #include <linux/netfilter_ipv4/ip_conntrack.h>
   5 #include <linux/netfilter/nfnetlink_conntrack.h>
   6
   7 struct seq_file;
   8
   9 struct ip_conntrack_protocol
  10 {
  11         /* Protocol number. */
  12         u_int8_t proto;
  13
  14         /* Protocol name */
  15         const char *name;
  16
  17         /* Try to fill in the third arg: dataoff is offset past IP
  18            hdr.  Return true if possible. */
  19         int (*pkt_to_tuple)(const struct sk_buff *skb,
  20                            unsigned int dataoff,
  21                            struct ip_conntrack_tuple *tuple);
  22
  23         /* Invert the per-proto part of the tuple: ie. turn xmit into reply.
  24          * Some packets can't be inverted: return 0 in that case.
  25          */
  26         int (*invert_tuple)(struct ip_conntrack_tuple *inverse,
  27                             const struct ip_conntrack_tuple *orig);
  28
  29         /* Print out the per-protocol part of the tuple. Return like seq_* */
  30         int (*print_tuple)(struct seq_file *,
  31                            const struct ip_conntrack_tuple *);
  32
  33         /* Print out the private part of the conntrack. */
  34         int (*print_conntrack)(struct seq_file *, const struct ip_conntrack *);
  35
  36         /* Returns verdict for packet, or -1 for invalid. */
  37         int (*packet)(struct ip_conntrack *conntrack,
  38                       const struct sk_buff *skb,
  39                       enum ip_conntrack_info ctinfo);
  40
  41         /* Called when a new connection for this protocol found;
  42          * returns TRUE if it's OK.  If so, packet() called next. */
  43         int (*new)(struct ip_conntrack *conntrack, const struct sk_buff *skb);
  44
  45         /* Called when a conntrack entry is destroyed */
  46         void (*destroy)(struct ip_conntrack *conntrack);
  47
  48         int (*error)(struct sk_buff *skb, enum ip_conntrack_info *ctinfo,
  49                      unsigned int hooknum);
  50
  51         /* convert protoinfo to nfnetink attributes */
  52         int (*to_nfattr)(struct sk_buff *skb, struct nfattr *nfa,
  53                          const struct ip_conntrack *ct);
  54
  55         /* convert nfnetlink attributes to protoinfo */
  56         int (*from_nfattr)(struct nfattr *tb[], struct ip_conntrack *ct);
  57
  58         int (*tuple_to_nfattr)(struct sk_buff *skb,
  59                                const struct ip_conntrack_tuple *t);
  60         int (*nfattr_to_tuple)(struct nfattr *tb[],
  61                                struct ip_conntrack_tuple *t);
  62
  63         /* Module (if any) which this is connected to. */
  64         struct module *me;
  65 };
  66
  67 /* Protocol registration. */
  68 extern int ip_conntrack_protocol_register(struct ip_conntrack_protocol *proto);
  69 extern void ip_conntrack_protocol_unregister(struct ip_conntrack_protocol *proto);
  70 /* Existing built-in protocols */
  71 extern struct ip_conntrack_protocol ip_conntrack_protocol_tcp;
  72 extern struct ip_conntrack_protocol ip_conntrack_protocol_udp;
  73 extern struct ip_conntrack_protocol ip_conntrack_protocol_icmp;
  74 extern struct ip_conntrack_protocol ip_conntrack_generic_protocol;
  75 extern int ip_conntrack_protocol_tcp_init(void);
  76
  77 /* Log invalid packets */
  78 extern unsigned int ip_ct_log_invalid;
  79
  80 extern int ip_ct_port_tuple_to_nfattr(struct sk_buff *,
  81                                       const struct ip_conntrack_tuple *);
  82 extern int ip_ct_port_nfattr_to_tuple(struct nfattr *tb[],
  83                                       struct ip_conntrack_tuple *);
  84
  85 #ifdef CONFIG_SYSCTL
  86 #ifdef DEBUG_INVALID_PACKETS
  87 #define LOG_INVALID(proto) \
  88         (ip_ct_log_invalid == (proto) || ip_ct_log_invalid == IPPROTO_RAW)
  89 #else
  90 #define LOG_INVALID(proto) \
  91         ((ip_ct_log_invalid == (proto) || ip_ct_log_invalid == IPPROTO_RAW) \
  92          && net_ratelimit())
  93 #endif
  94 #else
  95 #define LOG_INVALID(proto) 0
  96 #endif /* CONFIG_SYSCTL */
  97
  98 #endif /*_IP_CONNTRACK_PROTOCOL_H*/