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 /* L3 Protocol number. */
20 u_int16_t l3proto;
21
22 /* L4 Protocol number. */
23 u_int8_t l4proto;
24
25 /* Try to fill in the third arg: dataoff is offset past network protocol
26 hdr. Return true if possible. */
27 bool (*pkt_to_tuple)(const struct sk_buff *skb, unsigned int dataoff,
28 struct nf_conntrack_tuple *tuple);
29
30 /* Invert the per-proto part of the tuple: ie. turn xmit into reply.
31 * Some packets can't be inverted: return 0 in that case.
32 */
33 bool (*invert_tuple)(struct nf_conntrack_tuple *inverse,
34 const struct nf_conntrack_tuple *orig);
35
36 /* Returns verdict for packet, or -1 for invalid. */
37 int (*packet)(struct nf_conn *ct,
38 const struct sk_buff *skb,
39 unsigned int dataoff,
40 enum ip_conntrack_info ctinfo,
41 u_int8_t pf,
42 unsigned int hooknum);
43
44 /* Called when a new connection for this protocol found;
45 * returns TRUE if it's OK. If so, packet() called next. */
46 bool (*new)(struct nf_conn *ct, const struct sk_buff *skb,
47 unsigned int dataoff);
48
49 /* Called when a conntrack entry is destroyed */
50 void (*destroy)(struct nf_conn *ct);
51
52 int (*error)(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
53 unsigned int dataoff, enum ip_conntrack_info *ctinfo,
54 u_int8_t pf, unsigned int hooknum);
55
56 /* Print out the per-protocol part of the tuple. Return like seq_* */
57 int (*print_tuple)(struct seq_file *s,
58 const struct nf_conntrack_tuple *);
59
60 /* Print out the private part of the conntrack. */
61 int (*print_conntrack)(struct seq_file *s, struct nf_conn *);
62
63 /* convert protoinfo to nfnetink attributes */
64 int (*to_nlattr)(struct sk_buff *skb, struct nlattr *nla,
65 struct nf_conn *ct);
66 /* Calculate protoinfo nlattr size */
67 int (*nlattr_size)(void);
68
69 /* convert nfnetlink attributes to protoinfo */
70 int (*from_nlattr)(struct nlattr *tb[], struct nf_conn *ct);
71
72 int (*tuple_to_nlattr)(struct sk_buff *skb,
73 const struct nf_conntrack_tuple *t);
74 /* Calculate tuple nlattr size */
75 int (*nlattr_tuple_size)(void);
76 int (*nlattr_to_tuple)(struct nlattr *tb[],
77 struct nf_conntrack_tuple *t);
78 const struct nla_policy *nla_policy;
79
80 size_t nla_size;
81
82 #ifdef CONFIG_SYSCTL
83 struct ctl_table_header **ctl_table_header;
84 struct ctl_table *ctl_table;
85 unsigned int *ctl_table_users;
86 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
87 struct ctl_table_header *ctl_compat_table_header;
88 struct ctl_table *ctl_compat_table;
89 #endif
90 #endif
91 /* Protocol name */
92 const char *name;
93
94 /* Module (if any) which this is connected to. */
95 struct module *me;
96 };
97
98 /* Existing built-in generic protocol */
99 extern struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
100
101 #define MAX_NF_CT_PROTO 256
102
103 extern struct nf_conntrack_l4proto *
104 __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto);
105
106 /* Protocol registration. */
107 extern int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *proto);
108 extern void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *proto);
109
110 /* Generic netlink helpers */
111 extern int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
112 const struct nf_conntrack_tuple *tuple);
113 extern int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
114 struct nf_conntrack_tuple *t);
115 extern int nf_ct_port_nlattr_tuple_size(void);
116 extern const struct nla_policy nf_ct_port_nla_policy[];
117
118 #ifdef CONFIG_SYSCTL
119 #ifdef DEBUG_INVALID_PACKETS
120 #define LOG_INVALID(net, proto) \
121 ((net)->ct.sysctl_log_invalid == (proto) || \
122 (net)->ct.sysctl_log_invalid == IPPROTO_RAW)
123 #else
124 #define LOG_INVALID(net, proto) \
125 (((net)->ct.sysctl_log_invalid == (proto) || \
126 (net)->ct.sysctl_log_invalid == IPPROTO_RAW) \
127 && net_ratelimit())
128 #endif
129 #else
LOG_INVALID(struct net * net,int proto)130 static inline int LOG_INVALID(struct net *net, int proto) { return 0; }
131 #endif /* CONFIG_SYSCTL */
132
133 #endif /*_NF_CONNTRACK_PROTOCOL_H*/
134