[mirror_ubuntu-artful-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);
}

/* this can be increased when necessary - don't expose to userland */
#define NETLINK_MAX_COOKIE_LEN	20

/**
 * 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
 * @cookie: cookie data to return to userspace (for success)
 * @cookie_len: actual cookie data length
 */
struct netlink_ext_ack {
	const char *_msg;
	const struct nlattr *bad_attr;
	u8 cookie[NETLINK_MAX_COOKIE_LEN];
	u8 cookie_len;
};

/* 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);		\
	struct netlink_ext_ack *__extack = (extack);	\
							\
	if (__extack)					\
		__extack->_msg = __msg;			\
} while (0)

#define NL_SET_ERR_MSG_MOD(extack, msg)			\
	NL_SET_ERR_MSG((extack), KBUILD_MODNAME ": " msg)

#define NL_SET_BAD_ATTR(extack, attr) do {		\
	if ((extack))					\
		(extack)->bad_attr = (attr);		\
} while (0)

#define NL_SET_ERR_MSG_ATTR(extack, attr, msg) do {	\
	static const char __msg[] = (msg);		\
	struct netlink_ext_ack *__extack = (extack);	\
							\
	if (__extack) {					\
		__extack->_msg = __msg;			\
		__extack->bad_attr = (attr);		\
	}						\
} 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
ba0dc5f6 JB	65	/* this can be increased when necessary - don't expose to userland */
	66	#define NETLINK_MAX_COOKIE_LEN 20
	67
2d4bc933 JB	68	/**
	69	* struct netlink_ext_ack - netlink extended ACK report struct
	70	* @_msg: message string to report - don't access directly, use
	71	* %NL_SET_ERR_MSG
	72	* @bad_attr: attribute with error
ba0dc5f6 JB	73	* @cookie: cookie data to return to userspace (for success)
ba0dc5f6 JB	74	* @cookie_len: actual cookie data length
2d4bc933 JB	75	*/
	76	struct netlink_ext_ack {
	77	const char *_msg;
	78	const struct nlattr *bad_attr;
ba0dc5f6 JB	79	u8 cookie[NETLINK_MAX_COOKIE_LEN];
ba0dc5f6 JB	80	u8 cookie_len;
2d4bc933 JB	81	};
	82
	83	/* Always use this macro, this allows later putting the
	84	* message into a separate section or such for things
	85	* like translation or listing all possible messages.
	86	* Currently string formatting is not supported (due
	87	* to the lack of an output buffer.)
	88	*/
4d463c4d DB	89	#define NL_SET_ERR_MSG(extack, msg) do { \
	90	static const char __msg[] = (msg); \
	91	struct netlink_ext_ack *__extack = (extack); \
	92	\
	93	if (__extack) \
	94	__extack->_msg = __msg; \
2d4bc933 JB	95	} while (0)
2d4bc933 JB	96
4d463c4d DB	97	#define NL_SET_ERR_MSG_MOD(extack, msg) \
4d463c4d DB	98	NL_SET_ERR_MSG((extack), KBUILD_MODNAME ": " msg)
45d9b378	99
c3ab2b4e DA	100	#define NL_SET_BAD_ATTR(extack, attr) do { \
	101	if ((extack)) \
	102	(extack)->bad_attr = (attr); \
	103	} while (0)
	104
9ae28727 DA	105	#define NL_SET_ERR_MSG_ATTR(extack, attr, msg) do { \
	106	static const char __msg[] = (msg); \
	107	struct netlink_ext_ack *__extack = (extack); \
	108	\
	109	if (__extack) { \
	110	__extack->_msg = __msg; \
	111	__extack->bad_attr = (attr); \
	112	} \
	113	} while (0)
	114
b7c6ba6e	115	extern void netlink_kernel_release(struct sock *sk);
d136f1bd	116	extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
b4ff4f04	117	extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
b8273570	118	extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
2d4bc933 JB	119	extern void netlink_ack(struct sk_buff in_skb, struct nlmsghdr nlh, int err,
2d4bc933 JB	120	const struct netlink_ext_ack *extack);
4277a083	121	extern int netlink_has_listeners(struct sock *sk, unsigned int group);
6bb0fef4	122
15e47304 EB	123	extern int netlink_unicast(struct sock ssk, struct sk_buff skb, __u32 portid, int nonblock);
15e47304 EB	124	extern int netlink_broadcast(struct sock ssk, struct sk_buff skb, __u32 portid,
dd0fc66f	125	__u32 group, gfp_t allocation);
910a7e90	126	extern int netlink_broadcast_filtered(struct sock ssk, struct sk_buff skb,
15e47304	127	__u32 portid, __u32 group, gfp_t allocation,
910a7e90 EB	128	int (filter)(struct sock dsk, struct sk_buff skb, void data),
910a7e90 EB	129	void *filter_data);
15e47304	130	extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
1da177e4 LT	131	extern int netlink_register_notifier(struct notifier_block *nb);
	132	extern int netlink_unregister_notifier(struct notifier_block *nb);
	133
	134	/* finegrained unicast helpers: */
	135	struct sock netlink_getsockbyfilp(struct file filp);
9457afee	136	int netlink_attachskb(struct sock sk, struct sk_buff skb,
c3d8d1e3	137	long timeo, struct sock ssk);
1da177e4	138	void netlink_detachskb(struct sock sk, struct sk_buff skb);
7ee015e0	139	int netlink_sendskb(struct sock sk, struct sk_buff skb);
1da177e4	140
3a36515f PN	141	static inline struct sk_buff *
	142	netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
	143	{
	144	struct sk_buff *nskb;
	145
	146	nskb = skb_clone(skb, gfp_mask);
	147	if (!nskb)
	148	return NULL;
	149
	150	/* This is a large skb, set destructor callback to release head */
	151	if (is_vmalloc_addr(skb->head))
	152	nskb->destructor = skb->destructor;
	153
	154	return nskb;
	155	}
	156
1da177e4 LT	157	/*
1da177e4 LT	158	* skb should fit one page. This choice is good for headerless malloc.
fc910a27 DM	159	* But we should limit to 8K so that userspace does not have to
	160	* use enormous buffer sizes on recvmsg() calls just to avoid
	161	* MSG_TRUNC when PAGE_SIZE is very large.
1da177e4	162	*/
fc910a27 DM	163	#if PAGE_SIZE < 8192UL
	164	#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE)
	165	#else
	166	#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL)
	167	#endif
	168
339bf98f	169	#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
1da177e4 LT	170
1da177e4 LT	171
d94d9fee	172	struct netlink_callback {
3a6c2b41 PM	173	struct sk_buff *skb;
3a6c2b41 PM	174	const struct nlmsghdr *nlh;
fc9e50f5	175	int (start)(struct netlink_callback );
3a6c2b41 PM	176	int (dump)(struct sk_buff skb,
	177	struct netlink_callback *cb);
	178	int (done)(struct netlink_callback cb);
7175c883	179	void *data;
6dc878a8 G	180	/* the module that dump function belong to */
6dc878a8 G	181	struct module *module;
c7ac8679 GR	182	u16 family;
c7ac8679 GR	183	u16 min_dump_alloc;
670dc283	184	unsigned int prev_seq, seq;
3a6c2b41	185	long args[6];
1da177e4 LT	186	};
1da177e4 LT	187
d94d9fee	188	struct netlink_notify {
b4b51029	189	struct net *net;
0392d099	190	u32 portid;
1da177e4 LT	191	int protocol;
	192	};
	193
a46621a3	194	struct nlmsghdr *
15e47304	195	__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
1da177e4	196
80d326fa	197	struct netlink_dump_control {
fc9e50f5	198	int (start)(struct netlink_callback );
80d326fa	199	int (dump)(struct sk_buff skb, struct netlink_callback *);
6dc878a8	200	int (done)(struct netlink_callback );
7175c883	201	void *data;
6dc878a8	202	struct module *module;
80d326fa PNA	203	u16 min_dump_alloc;
	204	};
	205
6dc878a8 G	206	extern int __netlink_dump_start(struct sock ssk, struct sk_buff skb,
	207	const struct nlmsghdr *nlh,
	208	struct netlink_dump_control *control);
	209	static inline int netlink_dump_start(struct sock ssk, struct sk_buff skb,
	210	const struct nlmsghdr *nlh,
	211	struct netlink_dump_control *control)
	212	{
	213	if (!control->module)
	214	control->module = THIS_MODULE;
	215
	216	return __netlink_dump_start(ssk, skb, nlh, control);
	217	}
1da177e4	218
bcbde0d4 DB	219	struct netlink_tap {
	220	struct net_device *dev;
	221	struct module *module;
	222	struct list_head list;
	223	};
	224
	225	extern int netlink_add_tap(struct netlink_tap *nt);
bcbde0d4 DB	226	extern int netlink_remove_tap(struct netlink_tap *nt);
bcbde0d4 DB	227
aa4cf945 EB	228	bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
	229	struct user_namespace *ns, int cap);
	230	bool netlink_ns_capable(const struct sk_buff *skb,
	231	struct user_namespace *ns, int cap);
	232	bool netlink_capable(const struct sk_buff *skb, int cap);
	233	bool netlink_net_capable(const struct sk_buff *skb, int cap);
	234
1da177e4	235	#endif /* __LINUX_NETLINK_H */