1 #ifndef _NFNETLINK_H 2 #define _NFNETLINK_H 3 4 #include <linux/netlink.h> 5 #include <linux/capability.h> 6 #include <net/netlink.h> 7 #include <uapi/linux/netfilter/nfnetlink.h> 8 9 struct nfnl_callback { 10 int (*call)(struct net *net, struct sock *nl, struct sk_buff *skb, 11 const struct nlmsghdr *nlh, 12 const struct nlattr * const cda[], 13 struct netlink_ext_ack *extack); 14 int (*call_rcu)(struct net *net, struct sock *nl, struct sk_buff *skb, 15 const struct nlmsghdr *nlh, 16 const struct nlattr * const cda[], 17 struct netlink_ext_ack *extack); 18 int (*call_batch)(struct net *net, struct sock *nl, struct sk_buff *skb, 19 const struct nlmsghdr *nlh, 20 const struct nlattr * const cda[], 21 struct netlink_ext_ack *extack); 22 const struct nla_policy *policy; /* netlink attribute policy */ 23 const u_int16_t attr_count; /* number of nlattr's */ 24 }; 25 26 struct nfnetlink_subsystem { 27 const char *name; 28 __u8 subsys_id; /* nfnetlink subsystem ID */ 29 __u8 cb_count; /* number of callbacks */ 30 const struct nfnl_callback *cb; /* callback for individual types */ 31 int (*commit)(struct net *net, struct sk_buff *skb); 32 int (*abort)(struct net *net, struct sk_buff *skb); 33 bool (*valid_genid)(struct net *net, u32 genid); 34 }; 35 36 int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n); 37 int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n); 38 39 int nfnetlink_has_listeners(struct net *net, unsigned int group); 40 int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid, 41 unsigned int group, int echo, gfp_t flags); 42 int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error); 43 int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid, 44 int flags); 45 46 static inline u16 nfnl_msg_type(u8 subsys, u8 msg_type) 47 { 48 return subsys << 8 | msg_type; 49 } 50 51 void nfnl_lock(__u8 subsys_id); 52 void nfnl_unlock(__u8 subsys_id); 53 #ifdef CONFIG_PROVE_LOCKING 54 bool lockdep_nfnl_is_held(__u8 subsys_id); 55 #else 56 static inline bool lockdep_nfnl_is_held(__u8 subsys_id) 57 { 58 return true; 59 } 60 #endif /* CONFIG_PROVE_LOCKING */ 61 62 /* 63 * nfnl_dereference - fetch RCU pointer when updates are prevented by subsys mutex 64 * 65 * @p: The pointer to read, prior to dereferencing 66 * @ss: The nfnetlink subsystem ID 67 * 68 * Return the value of the specified RCU-protected pointer, but omit 69 * both the smp_read_barrier_depends() and the ACCESS_ONCE(), because 70 * caller holds the NFNL subsystem mutex. 71 */ 72 #define nfnl_dereference(p, ss) \ 73 rcu_dereference_protected(p, lockdep_nfnl_is_held(ss)) 74 75 #define MODULE_ALIAS_NFNL_SUBSYS(subsys) \ 76 MODULE_ALIAS("nfnetlink-subsys-" __stringify(subsys)) 77 78 #endif /* _NFNETLINK_H */ 79