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