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
  16 struct nf_conntrack_protocol
  17 {
  18         /* Next pointer. */
  19         struct list_head list;
  20
  21         /* L3 Protocol number. */
  22         u_int16_t l3proto;
  23
  24         /* Protocol number. */
  25         u_int8_t proto;
  26
  27         /* Protocol name */
  28         const char *name;
  29
  30         /* Try to fill in the third arg: dataoff is offset past network protocol
  31            hdr.  Return true if possible. */
  32         int (*pkt_to_tuple)(const struct sk_buff *skb,
  33                             unsigned int dataoff,
  34                             struct nf_conntrack_tuple *tuple);
  35
  36         /* Invert the per-proto part of the tuple: ie. turn xmit into reply.
  37          * Some packets can't be inverted: return 0 in that case.
  38          */
  39         int (*invert_tuple)(struct nf_conntrack_tuple *inverse,
  40                             const struct nf_conntrack_tuple *orig);
  41
  42         /* Print out the per-protocol part of the tuple. Return like seq_* */
  43         int (*print_tuple)(struct seq_file *s,
  44                            const struct nf_conntrack_tuple *);
  45
  46         /* Print out the private part of the conntrack. */
  47         int (*print_conntrack)(struct seq_file *s, const struct nf_conn *);
  48
  49         /* Returns verdict for packet, or -1 for invalid. */
  50         int (*packet)(struct nf_conn *conntrack,
  51                       const struct sk_buff *skb,
  52                       unsigned int dataoff,
  53                       enum ip_conntrack_info ctinfo,
  54                       int pf,
  55                       unsigned int hooknum);
  56
  57         /* Called when a new connection for this protocol found;
  58          * returns TRUE if it's OK.  If so, packet() called next. */
  59         int (*new)(struct nf_conn *conntrack, const struct sk_buff *skb,
  60                    unsigned int dataoff);
  61
  62         /* Called when a conntrack entry is destroyed */
  63         void (*destroy)(struct nf_conn *conntrack);
  64
  65         int (*error)(struct sk_buff *skb, unsigned int dataoff,
  66                      enum ip_conntrack_info *ctinfo,
  67                      int pf, unsigned int hooknum);
  68
  69         /* Module (if any) which this is connected to. */
  70         struct module *me;
  71 };
  72
  73 /* Existing built-in protocols */
  74 extern struct nf_conntrack_protocol nf_conntrack_protocol_tcp6;
  75 extern struct nf_conntrack_protocol nf_conntrack_protocol_udp4;
  76 extern struct nf_conntrack_protocol nf_conntrack_protocol_udp6;
  77 extern struct nf_conntrack_protocol nf_conntrack_generic_protocol;
  78
  79 #define MAX_NF_CT_PROTO 256
  80 extern struct nf_conntrack_protocol **nf_ct_protos[PF_MAX];
  81
  82 extern struct nf_conntrack_protocol *
  83 nf_ct_find_proto(u_int16_t l3proto, u_int8_t protocol);
  84
  85 /* Protocol registration. */
  86 extern int nf_conntrack_protocol_register(struct nf_conntrack_protocol *proto);
  87 extern void nf_conntrack_protocol_unregister(struct nf_conntrack_protocol *proto);
  88
  89 /* Log invalid packets */
  90 extern unsigned int nf_ct_log_invalid;
  91
  92 #ifdef CONFIG_SYSCTL
  93 #ifdef DEBUG_INVALID_PACKETS
  94 #define LOG_INVALID(proto) \
  95         (nf_ct_log_invalid == (proto) || nf_ct_log_invalid == IPPROTO_RAW)
  96 #else
  97 #define LOG_INVALID(proto) \
  98         ((nf_ct_log_invalid == (proto) || nf_ct_log_invalid == IPPROTO_RAW) \
  99          && net_ratelimit())
 100 #endif
 101 #else
 102 #define LOG_INVALID(proto) 0
 103 #endif /* CONFIG_SYSCTL */
 104
 105 #endif /*_NF_CONNTRACK_PROTOCOL_H*/