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