1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _NFNETLINK_H
3#define _NFNETLINK_H
4
5#include <linux/netlink.h>
6#include <linux/capability.h>
7#include <net/netlink.h>
8#include <uapi/linux/netfilter/nfnetlink.h>
9
10struct nfnl_info {
11	struct net		*net;
12	struct sock		*sk;
13	const struct nlmsghdr	*nlh;
14	const struct nfgenmsg	*nfmsg;
15	struct netlink_ext_ack	*extack;
16};
17
18enum nfnl_callback_type {
19	NFNL_CB_UNSPEC	= 0,
20	NFNL_CB_MUTEX,
21	NFNL_CB_RCU,
22	NFNL_CB_BATCH,
23};
24
25struct nfnl_callback {
26	int (*call)(struct sk_buff *skb, const struct nfnl_info *info,
27		    const struct nlattr * const cda[]);
28	const struct nla_policy	*policy;
29	enum nfnl_callback_type	type;
30	__u16			attr_count;
31};
32
33enum nfnl_abort_action {
34	NFNL_ABORT_NONE		= 0,
35	NFNL_ABORT_AUTOLOAD,
36	NFNL_ABORT_VALIDATE,
37};
38
39struct nfnetlink_subsystem {
40	const char *name;
41	__u8 subsys_id;			/* nfnetlink subsystem ID */
42	__u8 cb_count;			/* number of callbacks */
43	const struct nfnl_callback *cb;	/* callback for individual types */
44	struct module *owner;
45	int (*commit)(struct net *net, struct sk_buff *skb);
46	int (*abort)(struct net *net, struct sk_buff *skb,
47		     enum nfnl_abort_action action);
48	bool (*valid_genid)(struct net *net, u32 genid);
49};
50
51int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n);
52int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n);
53
54int nfnetlink_has_listeners(struct net *net, unsigned int group);
55int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid,
56		   unsigned int group, int echo, gfp_t flags);
57int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error);
58int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid);
59void nfnetlink_broadcast(struct net *net, struct sk_buff *skb, __u32 portid,
60			 __u32 group, gfp_t allocation);
61
62static inline u16 nfnl_msg_type(u8 subsys, u8 msg_type)
63{
64	return subsys << 8 | msg_type;
65}
66
67static inline void nfnl_fill_hdr(struct nlmsghdr *nlh, u8 family, u8 version,
68				 __be16 res_id)
69{
70	struct nfgenmsg *nfmsg;
71
72	nfmsg = nlmsg_data(nlh);
73	nfmsg->nfgen_family = family;
74	nfmsg->version = version;
75	nfmsg->res_id = res_id;
76}
77
78static inline struct nlmsghdr *nfnl_msg_put(struct sk_buff *skb, u32 portid,
79					    u32 seq, int type, int flags,
80					    u8 family, u8 version,
81					    __be16 res_id)
82{
83	struct nlmsghdr *nlh;
84
85	nlh = nlmsg_put(skb, portid, seq, type, sizeof(struct nfgenmsg), flags);
86	if (!nlh)
87		return NULL;
88
89	nfnl_fill_hdr(nlh, family, version, res_id);
90
91	return nlh;
92}
93
94void nfnl_lock(__u8 subsys_id);
95void nfnl_unlock(__u8 subsys_id);
96#ifdef CONFIG_PROVE_LOCKING
97bool lockdep_nfnl_is_held(__u8 subsys_id);
98#else
99static inline bool lockdep_nfnl_is_held(__u8 subsys_id)
100{
101	return true;
102}
103#endif /* CONFIG_PROVE_LOCKING */
104
105#define MODULE_ALIAS_NFNL_SUBSYS(subsys) \
106	MODULE_ALIAS("nfnetlink-subsys-" __stringify(subsys))
107
108#endif	/* _NFNETLINK_H */
109