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 62 static inline u16 nfnl_msg_type(u8 subsys, u8 msg_type) 63 { 64 return subsys << 8 | msg_type; 65 } 66 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 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 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