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
10 struct 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
18 enum nfnl_callback_type {
19 NFNL_CB_UNSPEC = 0,
20 NFNL_CB_MUTEX,
21 NFNL_CB_RCU,
22 NFNL_CB_BATCH,
23 };
24
25 struct 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
33 enum nfnl_abort_action {
34 NFNL_ABORT_NONE = 0,
35 NFNL_ABORT_AUTOLOAD,
36 NFNL_ABORT_VALIDATE,
37 };
38
39 struct 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 void (*cleanup)(struct net *net);
49 bool (*valid_genid)(struct net *net, u32 genid);
50 };
51
52 int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n);
53 int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n);
54
55 int nfnetlink_has_listeners(struct net *net, unsigned int group);
56 int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid,
57 unsigned int group, int echo, gfp_t flags);
58 int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error);
59 int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid);
60 void nfnetlink_broadcast(struct net *net, struct sk_buff *skb, __u32 portid,
61 __u32 group, gfp_t allocation);
62
nfnl_msg_type(u8 subsys,u8 msg_type)63 static inline u16 nfnl_msg_type(u8 subsys, u8 msg_type)
64 {
65 return subsys << 8 | msg_type;
66 }
67
nfnl_fill_hdr(struct nlmsghdr * nlh,u8 family,u8 version,__be16 res_id)68 static inline void nfnl_fill_hdr(struct nlmsghdr *nlh, u8 family, u8 version,
69 __be16 res_id)
70 {
71 struct nfgenmsg *nfmsg;
72
73 nfmsg = nlmsg_data(nlh);
74 nfmsg->nfgen_family = family;
75 nfmsg->version = version;
76 nfmsg->res_id = res_id;
77 }
78
nfnl_msg_put(struct sk_buff * skb,u32 portid,u32 seq,int type,int flags,u8 family,u8 version,__be16 res_id)79 static inline struct nlmsghdr *nfnl_msg_put(struct sk_buff *skb, u32 portid,
80 u32 seq, int type, int flags,
81 u8 family, u8 version,
82 __be16 res_id)
83 {
84 struct nlmsghdr *nlh;
85
86 nlh = nlmsg_put(skb, portid, seq, type, sizeof(struct nfgenmsg), flags);
87 if (!nlh)
88 return NULL;
89
90 nfnl_fill_hdr(nlh, family, version, res_id);
91
92 return nlh;
93 }
94
95 void nfnl_lock(__u8 subsys_id);
96 void nfnl_unlock(__u8 subsys_id);
97 #ifdef CONFIG_PROVE_LOCKING
98 bool lockdep_nfnl_is_held(__u8 subsys_id);
99 #else
lockdep_nfnl_is_held(__u8 subsys_id)100 static inline bool lockdep_nfnl_is_held(__u8 subsys_id)
101 {
102 return true;
103 }
104 #endif /* CONFIG_PROVE_LOCKING */
105
106 #define MODULE_ALIAS_NFNL_SUBSYS(subsys) \
107 MODULE_ALIAS("nfnetlink-subsys-" __stringify(subsys))
108
109 #endif /* _NFNETLINK_H */
110