1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Header for use in defining a given L4 protocol for connection tracking.
4 *
5 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
6 * - generalized L3 protocol dependent part.
7 *
8 * Derived from include/linux/netfiter_ipv4/ip_conntrack_protcol.h
9 */
10
11 #ifndef _NF_CONNTRACK_L4PROTO_H
12 #define _NF_CONNTRACK_L4PROTO_H
13 #include <linux/netlink.h>
14 #include <net/netlink.h>
15 #include <net/netfilter/nf_conntrack.h>
16 #include <net/netns/generic.h>
17
18 struct seq_file;
19
20 struct nf_conntrack_l4proto {
21 /* L3 Protocol number. */
22 u_int16_t l3proto;
23
24 /* L4 Protocol number. */
25 u_int8_t l4proto;
26
27 /* Resolve clashes on insertion races. */
28 bool allow_clash;
29
30 /* Try to fill in the third arg: dataoff is offset past network protocol
31 hdr. Return true if possible. */
32 bool (*pkt_to_tuple)(const struct sk_buff *skb, unsigned int dataoff,
33 struct net *net, struct nf_conntrack_tuple *tuple);
34
35 /* Invert the per-proto part of the tuple: ie. turn xmit into reply.
36 * Some packets can't be inverted: return 0 in that case.
37 */
38 bool (*invert_tuple)(struct nf_conntrack_tuple *inverse,
39 const struct nf_conntrack_tuple *orig);
40
41 /* Returns verdict for packet, or -1 for invalid. */
42 int (*packet)(struct nf_conn *ct,
43 const struct sk_buff *skb,
44 unsigned int dataoff,
45 enum ip_conntrack_info ctinfo,
46 u_int8_t pf,
47 unsigned int *timeouts);
48
49 /* Called when a new connection for this protocol found;
50 * returns TRUE if it's OK. If so, packet() called next. */
51 bool (*new)(struct nf_conn *ct, const struct sk_buff *skb,
52 unsigned int dataoff, unsigned int *timeouts);
53
54 /* Called when a conntrack entry is destroyed */
55 void (*destroy)(struct nf_conn *ct);
56
57 int (*error)(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
58 unsigned int dataoff,
59 u_int8_t pf, unsigned int hooknum);
60
61 /* called by gc worker if table is full */
62 bool (*can_early_drop)(const struct nf_conn *ct);
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 int (*nlattr_to_obj)(struct nlattr *tb[],
89 struct net *net, void *data);
90 int (*obj_to_nlattr)(struct sk_buff *skb, const void *data);
91
92 u16 obj_size;
93 u16 nlattr_max;
94 const struct nla_policy *nla_policy;
95 } ctnl_timeout;
96 #endif
97 #ifdef CONFIG_NF_CONNTRACK_PROCFS
98 /* Print out the private part of the conntrack. */
99 void (*print_conntrack)(struct seq_file *s, struct nf_conn *);
100 #endif
101 unsigned int *net_id;
102 /* Init l4proto pernet data */
103 int (*init_net)(struct net *net, u_int16_t proto);
104
105 /* Return the per-net protocol part. */
106 struct nf_proto_net *(*get_net_proto)(struct net *net);
107
108 /* Module (if any) which this is connected to. */
109 struct module *me;
110 };
111
112 /* Existing built-in generic protocol */
113 extern struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
114
115 #define MAX_NF_CT_PROTO 256
116
117 const struct nf_conntrack_l4proto *__nf_ct_l4proto_find(u_int16_t l3proto,
118 u_int8_t l4proto);
119
120 const struct nf_conntrack_l4proto *nf_ct_l4proto_find_get(u_int16_t l3proto,
121 u_int8_t l4proto);
122 void nf_ct_l4proto_put(const struct nf_conntrack_l4proto *p);
123
124 /* Protocol pernet registration. */
125 int nf_ct_l4proto_pernet_register_one(struct net *net,
126 const struct nf_conntrack_l4proto *proto);
127 void nf_ct_l4proto_pernet_unregister_one(struct net *net,
128 const struct nf_conntrack_l4proto *proto);
129 int nf_ct_l4proto_pernet_register(struct net *net,
130 struct nf_conntrack_l4proto *const proto[],
131 unsigned int num_proto);
132 void nf_ct_l4proto_pernet_unregister(struct net *net,
133 struct nf_conntrack_l4proto *const proto[],
134 unsigned int num_proto);
135
136 /* Protocol global registration. */
137 int nf_ct_l4proto_register_one(struct nf_conntrack_l4proto *proto);
138 void nf_ct_l4proto_unregister_one(const struct nf_conntrack_l4proto *proto);
139 int nf_ct_l4proto_register(struct nf_conntrack_l4proto *proto[],
140 unsigned int num_proto);
141 void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *proto[],
142 unsigned int num_proto);
143
144 /* Generic netlink helpers */
145 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
146 const struct nf_conntrack_tuple *tuple);
147 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
148 struct nf_conntrack_tuple *t);
149 int nf_ct_port_nlattr_tuple_size(void);
150 extern const struct nla_policy nf_ct_port_nla_policy[];
151
152 #ifdef CONFIG_SYSCTL
153 #define LOG_INVALID(net, proto) \
154 ((net)->ct.sysctl_log_invalid == (proto) || \
155 (net)->ct.sysctl_log_invalid == IPPROTO_RAW)
156 #else
LOG_INVALID(struct net * net,int proto)157 static inline int LOG_INVALID(struct net *net, int proto) { return 0; }
158 #endif /* CONFIG_SYSCTL */
159
160 #endif /*_NF_CONNTRACK_PROTOCOL_H*/
161