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 unsigned int *timeouts);
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, unsigned int *timeouts);
49
50 /* Called when a conntrack entry is destroyed */
51 void (*destroy)(struct nf_conn *ct);
52
53 int (*error)(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
54 unsigned int dataoff, 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, struct nf_conn *);
63
64 /* Return the array of timeouts for this protocol. */
65 unsigned int *(*get_timeouts)(struct net *net);
66
67 /* convert protoinfo to nfnetink attributes */
68 int (*to_nlattr)(struct sk_buff *skb, struct nlattr *nla,
69 struct nf_conn *ct);
70 /* Calculate protoinfo nlattr size */
71 int (*nlattr_size)(void);
72
73 /* convert nfnetlink attributes to protoinfo */
74 int (*from_nlattr)(struct nlattr *tb[], struct nf_conn *ct);
75
76 int (*tuple_to_nlattr)(struct sk_buff *skb,
77 const struct nf_conntrack_tuple *t);
78 /* Calculate tuple nlattr size */
79 int (*nlattr_tuple_size)(void);
80 int (*nlattr_to_tuple)(struct nlattr *tb[],
81 struct nf_conntrack_tuple *t);
82 const struct nla_policy *nla_policy;
83
84 size_t nla_size;
85
86 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
87 struct {
88 size_t obj_size;
89 int (*nlattr_to_obj)(struct nlattr *tb[], void *data);
90 int (*obj_to_nlattr)(struct sk_buff *skb, const void *data);
91
92 unsigned int nlattr_max;
93 const struct nla_policy *nla_policy;
94 } ctnl_timeout;
95 #endif
96
97 #ifdef CONFIG_SYSCTL
98 struct ctl_table_header **ctl_table_header;
99 struct ctl_table *ctl_table;
100 unsigned int *ctl_table_users;
101 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
102 struct ctl_table_header *ctl_compat_table_header;
103 struct ctl_table *ctl_compat_table;
104 #endif
105 #endif
106 /* Protocol name */
107 const char *name;
108
109 /* Module (if any) which this is connected to. */
110 struct module *me;
111 };
112
113 /* Existing built-in generic protocol */
114 extern struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
115
116 #define MAX_NF_CT_PROTO 256
117
118 extern struct nf_conntrack_l4proto *
119 __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto);
120
121 extern struct nf_conntrack_l4proto *
122 nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t l4proto);
123 extern void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p);
124
125 /* Protocol registration. */
126 extern int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *proto);
127 extern void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *proto);
128
129 /* Generic netlink helpers */
130 extern int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
131 const struct nf_conntrack_tuple *tuple);
132 extern int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
133 struct nf_conntrack_tuple *t);
134 extern int nf_ct_port_nlattr_tuple_size(void);
135 extern const struct nla_policy nf_ct_port_nla_policy[];
136
137 #ifdef CONFIG_SYSCTL
138 #ifdef DEBUG_INVALID_PACKETS
139 #define LOG_INVALID(net, proto) \
140 ((net)->ct.sysctl_log_invalid == (proto) || \
141 (net)->ct.sysctl_log_invalid == IPPROTO_RAW)
142 #else
143 #define LOG_INVALID(net, proto) \
144 (((net)->ct.sysctl_log_invalid == (proto) || \
145 (net)->ct.sysctl_log_invalid == IPPROTO_RAW) \
146 && net_ratelimit())
147 #endif
148 #else
LOG_INVALID(struct net * net,int proto)149 static inline int LOG_INVALID(struct net *net, int proto) { return 0; }
150 #endif /* CONFIG_SYSCTL */
151
152 #endif /*_NF_CONNTRACK_PROTOCOL_H*/
153