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 struct netlink_ext_ack *extack;
15 };
16
17 enum nfnl_callback_type {
18 NFNL_CB_UNSPEC = 0,
19 NFNL_CB_MUTEX,
20 NFNL_CB_RCU,
21 NFNL_CB_BATCH,
22 };
23
24 struct nfnl_callback {
25 int (*call)(struct sk_buff *skb, const struct nfnl_info *info,
26 const struct nlattr * const cda[]);
27 const struct nla_policy *policy;
28 enum nfnl_callback_type type;
29 __u16 attr_count;
30 };
31
32 enum nfnl_abort_action {
33 NFNL_ABORT_NONE = 0,
34 NFNL_ABORT_AUTOLOAD,
35 NFNL_ABORT_VALIDATE,
36 };
37
38 struct nfnetlink_subsystem {
39 const char *name;
40 __u8 subsys_id; /* nfnetlink subsystem ID */
41 __u8 cb_count; /* number of callbacks */
42 const struct nfnl_callback *cb; /* callback for individual types */
43 struct module *owner;
44 int (*commit)(struct net *net, struct sk_buff *skb);
45 int (*abort)(struct net *net, struct sk_buff *skb,
46 enum nfnl_abort_action action);
47 void (*cleanup)(struct net *net);
48 bool (*valid_genid)(struct net *net, u32 genid);
49 };
50
51 int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n);
52 int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n);
53
54 int nfnetlink_has_listeners(struct net *net, unsigned int group);
55 int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid,
56 unsigned int group, int echo, gfp_t flags);
57 int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error);
58 int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid);
59 void nfnetlink_broadcast(struct net *net, struct sk_buff *skb, __u32 portid,
60 __u32 group, gfp_t allocation);
61
nfnl_msg_type(u8 subsys,u8 msg_type)62 static inline u16 nfnl_msg_type(u8 subsys, u8 msg_type)
63 {
64 return subsys << 8 | msg_type;
65 }
66
nfnl_fill_hdr(struct nlmsghdr * nlh,u8 family,u8 version,__be16 res_id)67 static 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
nfnl_msg_put(struct sk_buff * skb,u32 portid,u32 seq,int type,int flags,u8 family,u8 version,__be16 res_id)78 static 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
94 void nfnl_lock(__u8 subsys_id);
95 void nfnl_unlock(__u8 subsys_id);
96 #ifdef CONFIG_PROVE_LOCKING
97 bool lockdep_nfnl_is_held(__u8 subsys_id);
98 #else
lockdep_nfnl_is_held(__u8 subsys_id)99 static 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