nfnetlink.h

  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
 10struct 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
 18enum nfnl_callback_type {
 19	NFNL_CB_UNSPEC	= 0,
 20	NFNL_CB_MUTEX,
 21	NFNL_CB_RCU,
 22	NFNL_CB_BATCH,
 23};
 24
 25struct 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
 33enum nfnl_abort_action {
 34	NFNL_ABORT_NONE		= 0,
 35	NFNL_ABORT_AUTOLOAD,
 36	NFNL_ABORT_VALIDATE,
 37};
 38
 39struct 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	bool (*valid_genid)(struct net *net, u32 genid);
 49};
 50
 51int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n);
 52int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n);
 53
 54int nfnetlink_has_listeners(struct net *net, unsigned int group);
 55int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid,
 56		   unsigned int group, int echo, gfp_t flags);
 57int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error);
 58int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid);
 59void nfnetlink_broadcast(struct net *net, struct sk_buff *skb, __u32 portid,
 60			 __u32 group, gfp_t allocation);
 61
 62static inline u16 nfnl_msg_type(u8 subsys, u8 msg_type)
 63{
 64	return subsys << 8 | msg_type;
 65}
 66
 67static 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
 78static 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
 94void nfnl_lock(__u8 subsys_id);
 95void nfnl_unlock(__u8 subsys_id);
 96#ifdef CONFIG_PROVE_LOCKING
 97bool lockdep_nfnl_is_held(__u8 subsys_id);
 98#else
 99static 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 */