[mirror_ubuntu-bionic-kernel.git] / include / linux / netlink.h

#ifndef __LINUX_NETLINK_H
#define __LINUX_NETLINK_H


#include <linux/capability.h>
#include <linux/skbuff.h>
#include <linux/export.h>
#include <net/scm.h>
#include <uapi/linux/netlink.h>

struct net;

static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
{
	return (struct nlmsghdr *)skb->data;
}

enum netlink_skb_flags {
	NETLINK_SKB_MMAPED	= 0x1,	/* Packet data is mmaped */
	NETLINK_SKB_TX		= 0x2,	/* Packet was sent by userspace */
	NETLINK_SKB_DELIVERED	= 0x4,	/* Packet was delivered */
	NETLINK_SKB_DST		= 0x8,	/* Dst set in sendto or sendmsg */
};

struct netlink_skb_parms {
	struct scm_creds	creds;		/* Skb credentials	*/
	__u32			portid;
	__u32			dst_group;
	__u32			flags;
	struct sock		*sk;
	bool			nsid_is_set;
	int			nsid;
};

#define NETLINK_CB(skb)		(*(struct netlink_skb_parms*)&((skb)->cb))
#define NETLINK_CREDS(skb)	(&NETLINK_CB((skb)).creds)


extern void netlink_table_grab(void);
extern void netlink_table_ungrab(void);

#define NL_CFG_F_NONROOT_RECV	(1 << 0)
#define NL_CFG_F_NONROOT_SEND	(1 << 1)

/* optional Netlink kernel configuration parameters */
struct netlink_kernel_cfg {
	unsigned int	groups;
	unsigned int	flags;
	void		(*input)(struct sk_buff *skb);
	struct mutex	*cb_mutex;
	int		(*bind)(struct net *net, int group);
	void		(*unbind)(struct net *net, int group);
	bool		(*compare)(struct net *net, struct sock *sk);
};

extern struct sock *__netlink_kernel_create(struct net *net, int unit,
					    struct module *module,
					    struct netlink_kernel_cfg *cfg);
static inline struct sock *
netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg)
{
	return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
}

/**
 * struct netlink_ext_ack - netlink extended ACK report struct
 * @_msg: message string to report - don't access directly, use
 *	%NL_SET_ERR_MSG
 * @bad_attr: attribute with error
 */
struct netlink_ext_ack {
	const char *_msg;
	const struct nlattr *bad_attr;
};

/* Always use this macro, this allows later putting the
 * message into a separate section or such for things
 * like translation or listing all possible messages.
 * Currently string formatting is not supported (due
 * to the lack of an output buffer.)
 */
#define NL_SET_ERR_MSG(extack, msg) do {	\
	static const char _msg[] = (msg);	\
						\
	(extack)->_msg = _msg;			\
} while (0)

extern void netlink_kernel_release(struct sock *sk);
extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
			const struct netlink_ext_ack *extack);
extern int netlink_has_listeners(struct sock *sk, unsigned int group);

extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
			     __u32 group, gfp_t allocation);
extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
	__u32 portid, __u32 group, gfp_t allocation,
	int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
	void *filter_data);
extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
extern int netlink_register_notifier(struct notifier_block *nb);
extern int netlink_unregister_notifier(struct notifier_block *nb);

/* finegrained unicast helpers: */
struct sock *netlink_getsockbyfilp(struct file *filp);
int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
		      long *timeo, struct sock *ssk);
void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
int netlink_sendskb(struct sock *sk, struct sk_buff *skb);

static inline struct sk_buff *
netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
{
	struct sk_buff *nskb;

	nskb = skb_clone(skb, gfp_mask);
	if (!nskb)
		return NULL;

	/* This is a large skb, set destructor callback to release head */
	if (is_vmalloc_addr(skb->head))
		nskb->destructor = skb->destructor;

	return nskb;
}

/*
 *	skb should fit one page. This choice is good for headerless malloc.
 *	But we should limit to 8K so that userspace does not have to
 *	use enormous buffer sizes on recvmsg() calls just to avoid
 *	MSG_TRUNC when PAGE_SIZE is very large.
 */
#if PAGE_SIZE < 8192UL
#define NLMSG_GOODSIZE	SKB_WITH_OVERHEAD(PAGE_SIZE)
#else
#define NLMSG_GOODSIZE	SKB_WITH_OVERHEAD(8192UL)
#endif

#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)


struct netlink_callback {
	struct sk_buff		*skb;
	const struct nlmsghdr	*nlh;
	int			(*start)(struct netlink_callback *);
	int			(*dump)(struct sk_buff * skb,
					struct netlink_callback *cb);
	int			(*done)(struct netlink_callback *cb);
	void			*data;
	/* the module that dump function belong to */
	struct module		*module;
	u16			family;
	u16			min_dump_alloc;
	unsigned int		prev_seq, seq;
	long			args[6];
};

struct netlink_notify {
	struct net *net;
	u32 portid;
	int protocol;
};

struct nlmsghdr *
__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);

struct netlink_dump_control {
	int (*start)(struct netlink_callback *);
	int (*dump)(struct sk_buff *skb, struct netlink_callback *);
	int (*done)(struct netlink_callback *);
	void *data;
	struct module *module;
	u16 min_dump_alloc;
};

extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
				const struct nlmsghdr *nlh,
				struct netlink_dump_control *control);
static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
				     const struct nlmsghdr *nlh,
				     struct netlink_dump_control *control)
{
	if (!control->module)
		control->module = THIS_MODULE;

	return __netlink_dump_start(ssk, skb, nlh, control);
}

struct netlink_tap {
	struct net_device *dev;
	struct module *module;
	struct list_head list;
};

extern int netlink_add_tap(struct netlink_tap *nt);
extern int netlink_remove_tap(struct netlink_tap *nt);

bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
			  struct user_namespace *ns, int cap);
bool netlink_ns_capable(const struct sk_buff *skb,
			struct user_namespace *ns, int cap);
bool netlink_capable(const struct sk_buff *skb, int cap);
bool netlink_net_capable(const struct sk_buff *skb, int cap);

#endif	/* __LINUX_NETLINK_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef __LINUX_NETLINK_H
	2	#define __LINUX_NETLINK_H
	3
1da177e4 LT	4
	5	#include <linux/capability.h>
	6	#include <linux/skbuff.h>
abb17e6c	7	#include <linux/export.h>
dbe9a417	8	#include <net/scm.h>
607ca46e	9	#include <uapi/linux/netlink.h>
1da177e4	10
56b49f4b OW	11	struct net;
56b49f4b OW	12
b529ccf2 ACM	13	static inline struct nlmsghdr nlmsg_hdr(const struct sk_buff skb)
	14	{
	15	return (struct nlmsghdr *)skb->data;
	16	}
	17
9652e931	18	enum netlink_skb_flags {
2d7a85f4 EB	19	NETLINK_SKB_MMAPED = 0x1, /* Packet data is mmaped */
	20	NETLINK_SKB_TX = 0x2, /* Packet was sent by userspace */
	21	NETLINK_SKB_DELIVERED = 0x4, /* Packet was delivered */
	22	NETLINK_SKB_DST = 0x8, /* Dst set in sendto or sendmsg */
9652e931 PM	23	};
9652e931 PM	24
d94d9fee	25	struct netlink_skb_parms {
dbe9a417	26	struct scm_creds creds; /* Skb credentials */
15e47304	27	__u32 portid;
d629b836	28	__u32 dst_group;
9652e931	29	__u32 flags;
e32123e5	30	struct sock *sk;
59324cf3 ND	31	bool nsid_is_set;
59324cf3 ND	32	int nsid;
1da177e4 LT	33	};
	34
	35	#define NETLINK_CB(skb) ((struct netlink_skb_parms)&((skb)->cb))
	36	#define NETLINK_CREDS(skb) (&NETLINK_CB((skb)).creds)
	37
	38
d136f1bd JB	39	extern void netlink_table_grab(void);
	40	extern void netlink_table_ungrab(void);
	41
9785e10a PNA	42	#define NL_CFG_F_NONROOT_RECV (1 << 0)
	43	#define NL_CFG_F_NONROOT_SEND (1 << 1)
	44
a31f2d17 PNA	45	/* optional Netlink kernel configuration parameters */
	46	struct netlink_kernel_cfg {
	47	unsigned int groups;
c9d2ea96	48	unsigned int flags;
a31f2d17 PNA	49	void (input)(struct sk_buff skb);
a31f2d17 PNA	50	struct mutex *cb_mutex;
023e2cfa JB	51	int (bind)(struct net net, int group);
023e2cfa JB	52	void (unbind)(struct net net, int group);
da12c90e	53	bool (compare)(struct net net, struct sock *sk);
a31f2d17 PNA	54	};
a31f2d17 PNA	55
9f00d977 PNA	56	extern struct sock __netlink_kernel_create(struct net net, int unit,
	57	struct module *module,
	58	struct netlink_kernel_cfg *cfg);
	59	static inline struct sock *
	60	netlink_kernel_create(struct net net, int unit, struct netlink_kernel_cfg cfg)
	61	{
	62	return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
	63	}
	64
2d4bc933 JB	65	/**
	66	* struct netlink_ext_ack - netlink extended ACK report struct
	67	* @_msg: message string to report - don't access directly, use
	68	* %NL_SET_ERR_MSG
	69	* @bad_attr: attribute with error
	70	*/
	71	struct netlink_ext_ack {
	72	const char *_msg;
	73	const struct nlattr *bad_attr;
	74	};
	75
	76	/* Always use this macro, this allows later putting the
	77	* message into a separate section or such for things
	78	* like translation or listing all possible messages.
	79	* Currently string formatting is not supported (due
	80	* to the lack of an output buffer.)
	81	*/
	82	#define NL_SET_ERR_MSG(extack, msg) do { \
	83	static const char _msg[] = (msg); \
	84	\
	85	(extack)->_msg = _msg; \
	86	} while (0)
	87
b7c6ba6e	88	extern void netlink_kernel_release(struct sock *sk);
d136f1bd	89	extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
b4ff4f04	90	extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
b8273570	91	extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
2d4bc933 JB	92	extern void netlink_ack(struct sk_buff in_skb, struct nlmsghdr nlh, int err,
2d4bc933 JB	93	const struct netlink_ext_ack *extack);
4277a083	94	extern int netlink_has_listeners(struct sock *sk, unsigned int group);
6bb0fef4	95
15e47304 EB	96	extern int netlink_unicast(struct sock ssk, struct sk_buff skb, __u32 portid, int nonblock);
15e47304 EB	97	extern int netlink_broadcast(struct sock ssk, struct sk_buff skb, __u32 portid,
dd0fc66f	98	__u32 group, gfp_t allocation);
910a7e90	99	extern int netlink_broadcast_filtered(struct sock ssk, struct sk_buff skb,
15e47304	100	__u32 portid, __u32 group, gfp_t allocation,
910a7e90 EB	101	int (filter)(struct sock dsk, struct sk_buff skb, void data),
910a7e90 EB	102	void *filter_data);
15e47304	103	extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
1da177e4 LT	104	extern int netlink_register_notifier(struct notifier_block *nb);
	105	extern int netlink_unregister_notifier(struct notifier_block *nb);
	106
	107	/* finegrained unicast helpers: */
	108	struct sock netlink_getsockbyfilp(struct file filp);
9457afee	109	int netlink_attachskb(struct sock sk, struct sk_buff skb,
c3d8d1e3	110	long timeo, struct sock ssk);
1da177e4	111	void netlink_detachskb(struct sock sk, struct sk_buff skb);
7ee015e0	112	int netlink_sendskb(struct sock sk, struct sk_buff skb);
1da177e4	113
3a36515f PN	114	static inline struct sk_buff *
	115	netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
	116	{
	117	struct sk_buff *nskb;
	118
	119	nskb = skb_clone(skb, gfp_mask);
	120	if (!nskb)
	121	return NULL;
	122
	123	/* This is a large skb, set destructor callback to release head */
	124	if (is_vmalloc_addr(skb->head))
	125	nskb->destructor = skb->destructor;
	126
	127	return nskb;
	128	}
	129
1da177e4 LT	130	/*
1da177e4 LT	131	* skb should fit one page. This choice is good for headerless malloc.
fc910a27 DM	132	* But we should limit to 8K so that userspace does not have to
	133	* use enormous buffer sizes on recvmsg() calls just to avoid
	134	* MSG_TRUNC when PAGE_SIZE is very large.
1da177e4	135	*/
fc910a27 DM	136	#if PAGE_SIZE < 8192UL
	137	#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE)
	138	#else
	139	#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL)
	140	#endif
	141
339bf98f	142	#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
1da177e4 LT	143
1da177e4 LT	144
d94d9fee	145	struct netlink_callback {
3a6c2b41 PM	146	struct sk_buff *skb;
3a6c2b41 PM	147	const struct nlmsghdr *nlh;
fc9e50f5	148	int (start)(struct netlink_callback );
3a6c2b41 PM	149	int (dump)(struct sk_buff skb,
	150	struct netlink_callback *cb);
	151	int (done)(struct netlink_callback cb);
7175c883	152	void *data;
6dc878a8 G	153	/* the module that dump function belong to */
6dc878a8 G	154	struct module *module;
c7ac8679 GR	155	u16 family;
c7ac8679 GR	156	u16 min_dump_alloc;
670dc283	157	unsigned int prev_seq, seq;
3a6c2b41	158	long args[6];
1da177e4 LT	159	};
1da177e4 LT	160
d94d9fee	161	struct netlink_notify {
b4b51029	162	struct net *net;
0392d099	163	u32 portid;
1da177e4 LT	164	int protocol;
	165	};
	166
a46621a3	167	struct nlmsghdr *
15e47304	168	__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
1da177e4	169
80d326fa	170	struct netlink_dump_control {
fc9e50f5	171	int (start)(struct netlink_callback );
80d326fa	172	int (dump)(struct sk_buff skb, struct netlink_callback *);
6dc878a8	173	int (done)(struct netlink_callback );
7175c883	174	void *data;
6dc878a8	175	struct module *module;
80d326fa PNA	176	u16 min_dump_alloc;
	177	};
	178
6dc878a8 G	179	extern int __netlink_dump_start(struct sock ssk, struct sk_buff skb,
	180	const struct nlmsghdr *nlh,
	181	struct netlink_dump_control *control);
	182	static inline int netlink_dump_start(struct sock ssk, struct sk_buff skb,
	183	const struct nlmsghdr *nlh,
	184	struct netlink_dump_control *control)
	185	{
	186	if (!control->module)
	187	control->module = THIS_MODULE;
	188
	189	return __netlink_dump_start(ssk, skb, nlh, control);
	190	}
1da177e4	191
bcbde0d4 DB	192	struct netlink_tap {
	193	struct net_device *dev;
	194	struct module *module;
	195	struct list_head list;
	196	};
	197
	198	extern int netlink_add_tap(struct netlink_tap *nt);
bcbde0d4 DB	199	extern int netlink_remove_tap(struct netlink_tap *nt);
bcbde0d4 DB	200
aa4cf945 EB	201	bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
	202	struct user_namespace *ns, int cap);
	203	bool netlink_ns_capable(const struct sk_buff *skb,
	204	struct user_namespace *ns, int cap);
	205	bool netlink_capable(const struct sk_buff *skb, int cap);
	206	bool netlink_net_capable(const struct sk_buff *skb, int cap);
	207
1da177e4	208	#endif /* __LINUX_NETLINK_H */