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
   6 struct seq_file;
   7
   8 struct ip_conntrack_protocol
   9 {
  10         /* Protocol number. */
  11         u_int8_t proto;
  12
  13         /* Protocol name */
  14         const char *name;
  15
  16         /* Try to fill in the third arg: dataoff is offset past IP
  17            hdr.  Return true if possible. */
  18         int (*pkt_to_tuple)(const struct sk_buff *skb,
  19                            unsigned int dataoff,
  20                            struct ip_conntrack_tuple *tuple);
  21
  22         /* Invert the per-proto part of the tuple: ie. turn xmit into reply.
  23          * Some packets can't be inverted: return 0 in that case.
  24          */
  25         int (*invert_tuple)(struct ip_conntrack_tuple *inverse,
  26                             const struct ip_conntrack_tuple *orig);
  27
  28         /* Print out the per-protocol part of the tuple. Return like seq_* */
  29         int (*print_tuple)(struct seq_file *,
  30                            const struct ip_conntrack_tuple *);
  31
  32         /* Print out the private part of the conntrack. */
  33         int (*print_conntrack)(struct seq_file *, const struct ip_conntrack *);
  34
  35         /* Returns verdict for packet, or -1 for invalid. */
  36         int (*packet)(struct ip_conntrack *conntrack,
  37                       const struct sk_buff *skb,
  38                       enum ip_conntrack_info ctinfo);
  39
  40         /* Called when a new connection for this protocol found;
  41          * returns TRUE if it's OK.  If so, packet() called next. */
  42         int (*new)(struct ip_conntrack *conntrack, const struct sk_buff *skb);
  43
  44         /* Called when a conntrack entry is destroyed */
  45         void (*destroy)(struct ip_conntrack *conntrack);
  46
  47         int (*error)(struct sk_buff *skb, enum ip_conntrack_info *ctinfo,
  48                      unsigned int hooknum);
  49
  50         /* Module (if any) which this is connected to. */
  51         struct module *me;
  52 };
  53
  54 #define MAX_IP_CT_PROTO 256
  55 extern struct ip_conntrack_protocol *ip_ct_protos[MAX_IP_CT_PROTO];
  56
  57 /* Protocol registration. */
  58 extern int ip_conntrack_protocol_register(struct ip_conntrack_protocol *proto);
  59 extern void ip_conntrack_protocol_unregister(struct ip_conntrack_protocol *proto);
  60
  61 static inline struct ip_conntrack_protocol *ip_ct_find_proto(u_int8_t protocol)
  62 {
  63         return ip_ct_protos[protocol];
  64 }
  65
  66 /* Existing built-in protocols */
  67 extern struct ip_conntrack_protocol ip_conntrack_protocol_tcp;
  68 extern struct ip_conntrack_protocol ip_conntrack_protocol_udp;
  69 extern struct ip_conntrack_protocol ip_conntrack_protocol_icmp;
  70 extern struct ip_conntrack_protocol ip_conntrack_generic_protocol;
  71 extern int ip_conntrack_protocol_tcp_init(void);
  72
  73 /* Log invalid packets */
  74 extern unsigned int ip_ct_log_invalid;
  75
  76 #ifdef CONFIG_SYSCTL
  77 #ifdef DEBUG_INVALID_PACKETS
  78 #define LOG_INVALID(proto) \
  79         (ip_ct_log_invalid == (proto) || ip_ct_log_invalid == IPPROTO_RAW)
  80 #else
  81 #define LOG_INVALID(proto) \
  82         ((ip_ct_log_invalid == (proto) || ip_ct_log_invalid == IPPROTO_RAW) \
  83          && net_ratelimit())
  84 #endif
  85 #else
  86 #define LOG_INVALID(proto) 0
  87 #endif /* CONFIG_SYSCTL */
  88
  89 #endif /*_IP_CONNTRACK_PROTOCOL_H*/