[linux-block.git] / include / linux / netlink.h

/* SPDX-License-Identifier: GPL-2.0 */
#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;

void do_trace_netlink_extack(const char *msg);

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

enum netlink_skb_flags {
	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)


void netlink_table_grab(void);
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);
};

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
#define NETLINK_MAX_FMTMSG_LEN	80

/**
 * 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
 * @policy: policy for a bad attribute
 * @miss_type: attribute type which was missing
 * @miss_nest: nest missing an attribute (%NULL if missing top level attr)
 * @cookie: cookie data to return to userspace (for success)
 * @cookie_len: actual cookie data length
 * @_msg_buf: output buffer for formatted message strings - don't access
 *	directly, use %NL_SET_ERR_MSG_FMT
 */
struct netlink_ext_ack {
	const char *_msg;
	const struct nlattr *bad_attr;
	const struct nla_policy *policy;
	const struct nlattr *miss_nest;
	u16 miss_type;
	u8 cookie[NETLINK_MAX_COOKIE_LEN];
	u8 cookie_len;
	char _msg_buf[NETLINK_MAX_FMTMSG_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.
 * If string formatting is needed use NL_SET_ERR_MSG_FMT.
 */
#define NL_SET_ERR_MSG(extack, msg) do {		\
	static const char __msg[] = msg;		\
	struct netlink_ext_ack *__extack = (extack);	\
							\
	do_trace_netlink_extack(__msg);			\
							\
	if (__extack)					\
		__extack->_msg = __msg;			\
} while (0)

/* We splice fmt with %s at each end even in the snprintf so that both calls
 * can use the same string constant, avoiding its duplication in .ro
 */
#define NL_SET_ERR_MSG_FMT(extack, fmt, args...) do {			       \
	struct netlink_ext_ack *__extack = (extack);			       \
									       \
	if (!__extack)							       \
		break;							       \
	if (snprintf(__extack->_msg_buf, NETLINK_MAX_FMTMSG_LEN,	       \
		     "%s" fmt "%s", "", ##args, "") >=			       \
	    NETLINK_MAX_FMTMSG_LEN)					       \
		net_warn_ratelimited("%s" fmt "%s", "truncated extack: ",      \
				     ##args, "\n");			       \
									       \
	do_trace_netlink_extack(__extack->_msg_buf);			       \
									       \
	__extack->_msg = __extack->_msg_buf;				       \
} while (0)

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

#define NL_SET_ERR_MSG_FMT_MOD(extack, fmt, args...)	\
	NL_SET_ERR_MSG_FMT((extack), KBUILD_MODNAME ": " fmt, ##args)

#define NL_SET_ERR_MSG_WEAK(extack, msg) do {		\
	if ((extack) && !(extack)->_msg)		\
		NL_SET_ERR_MSG((extack), msg);		\
} while (0)

#define NL_SET_ERR_MSG_WEAK_MOD(extack, msg) do {	\
	if ((extack) && !(extack)->_msg)		\
		NL_SET_ERR_MSG_MOD((extack), msg);	\
} while (0)

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

#define NL_SET_BAD_ATTR(extack, attr) NL_SET_BAD_ATTR_POLICY(extack, attr, NULL)

#define NL_SET_ERR_MSG_ATTR_POL(extack, attr, pol, msg) do {	\
	static const char __msg[] = msg;			\
	struct netlink_ext_ack *__extack = (extack);		\
								\
	do_trace_netlink_extack(__msg);				\
								\
	if (__extack) {						\
		__extack->_msg = __msg;				\
		__extack->bad_attr = (attr);			\
		__extack->policy = (pol);			\
	}							\
} while (0)

#define NL_SET_ERR_MSG_ATTR_POL_FMT(extack, attr, pol, fmt, args...) do {	\
	struct netlink_ext_ack *__extack = (extack);				\
										\
	if (!__extack)								\
		break;								\
										\
	if (snprintf(__extack->_msg_buf, NETLINK_MAX_FMTMSG_LEN,		\
		     "%s" fmt "%s", "", ##args, "") >=				\
	    NETLINK_MAX_FMTMSG_LEN)						\
		net_warn_ratelimited("%s" fmt "%s", "truncated extack: ",       \
				     ##args, "\n");				\
										\
	do_trace_netlink_extack(__extack->_msg_buf);				\
										\
	__extack->_msg = __extack->_msg_buf;					\
	__extack->bad_attr = (attr);						\
	__extack->policy = (pol);						\
} while (0)

#define NL_SET_ERR_MSG_ATTR(extack, attr, msg)		\
	NL_SET_ERR_MSG_ATTR_POL(extack, attr, NULL, msg)

#define NL_SET_ERR_MSG_ATTR_FMT(extack, attr, msg, args...) \
	NL_SET_ERR_MSG_ATTR_POL_FMT(extack, attr, NULL, msg, ##args)

#define NL_SET_ERR_ATTR_MISS(extack, nest, type)  do {	\
	struct netlink_ext_ack *__extack = (extack);	\
							\
	if (__extack) {					\
		__extack->miss_nest = (nest);		\
		__extack->miss_type = (type);		\
	}						\
} while (0)

#define NL_REQ_ATTR_CHECK(extack, nest, tb, type) ({		\
	struct nlattr **__tb = (tb);				\
	u32 __attr = (type);					\
	int __retval;						\
								\
	__retval = !__tb[__attr];				\
	if (__retval)						\
		NL_SET_ERR_ATTR_MISS((extack), (nest), __attr);	\
	__retval;						\
})

static inline void nl_set_extack_cookie_u64(struct netlink_ext_ack *extack,
					    u64 cookie)
{
	if (!extack)
		return;
	memcpy(extack->cookie, &cookie, sizeof(cookie));
	extack->cookie_len = sizeof(cookie);
}

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

int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
		      __u32 group, gfp_t allocation);
int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
int netlink_register_notifier(struct notifier_block *nb);
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			(*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;
	struct netlink_ext_ack	*extack;
	u16			family;
	u16			answer_flags;
	u32			min_dump_alloc;
	unsigned int		prev_seq, seq;
	bool			strict_check;
	union {
		u8		ctx[48];

		/* args is deprecated. Cast a struct over ctx instead
		 * for proper type safety.
		 */
		long		args[6];
	};
};

#define NL_ASSERT_DUMP_CTX_FITS(type_name)				\
	BUILD_BUG_ON(sizeof(type_name) >				\
		     sizeof_field(struct netlink_callback, ctx))

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;
	u32 min_dump_alloc;
};

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;
};

int netlink_add_tap(struct netlink_tap *nt);
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
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	2	#ifndef __LINUX_NETLINK_H
	3	#define __LINUX_NETLINK_H
	4
1da177e4 LT	5
	6	#include <linux/capability.h>
	7	#include <linux/skbuff.h>
abb17e6c	8	#include <linux/export.h>
dbe9a417	9	#include <net/scm.h>
607ca46e	10	#include <uapi/linux/netlink.h>
1da177e4	11
56b49f4b OW	12	struct net;
56b49f4b OW	13
7e3ce05e MRL	14	void do_trace_netlink_extack(const char *msg);
7e3ce05e MRL	15
b529ccf2 ACM	16	static inline struct nlmsghdr nlmsg_hdr(const struct sk_buff skb)
	17	{
	18	return (struct nlmsghdr *)skb->data;
	19	}
	20
9652e931	21	enum netlink_skb_flags {
2d7a85f4	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
aa9d6e0f SH	39	void netlink_table_grab(void);
aa9d6e0f SH	40	void netlink_table_ungrab(void);
d136f1bd	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);
a31f2d17 PNA	53	};
a31f2d17 PNA	54
aa9d6e0f	55	struct sock __netlink_kernel_create(struct net net, int unit,
9f00d977 PNA	56	struct module *module,
	57	struct netlink_kernel_cfg *cfg);
	58	static inline struct sock *
	59	netlink_kernel_create(struct net net, int unit, struct netlink_kernel_cfg cfg)
	60	{
	61	return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
	62	}
	63
ba0dc5f6 JB	64	/* this can be increased when necessary - don't expose to userland */
ba0dc5f6 JB	65	#define NETLINK_MAX_COOKIE_LEN 20
51c352bd	66	#define NETLINK_MAX_FMTMSG_LEN 80
ba0dc5f6	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
44f3625b	73	* @policy: policy for a bad attribute
690252f1 JK	74	* @miss_type: attribute type which was missing
690252f1 JK	75	* @miss_nest: nest missing an attribute (%NULL if missing top level attr)
ba0dc5f6 JB	76	* @cookie: cookie data to return to userspace (for success)
ba0dc5f6 JB	77	* @cookie_len: actual cookie data length
51c352bd EC	78	* @_msg_buf: output buffer for formatted message strings - don't access
51c352bd EC	79	* directly, use %NL_SET_ERR_MSG_FMT
2d4bc933 JB	80	*/
	81	struct netlink_ext_ack {
	82	const char *_msg;
	83	const struct nlattr *bad_attr;
44f3625b	84	const struct nla_policy *policy;
690252f1 JK	85	const struct nlattr *miss_nest;
690252f1 JK	86	u16 miss_type;
ba0dc5f6 JB	87	u8 cookie[NETLINK_MAX_COOKIE_LEN];
ba0dc5f6 JB	88	u8 cookie_len;
51c352bd	89	char _msg_buf[NETLINK_MAX_FMTMSG_LEN];
2d4bc933 JB	90	};
	91
	92	/* Always use this macro, this allows later putting the
	93	* message into a separate section or such for things
	94	* like translation or listing all possible messages.
51c352bd	95	* If string formatting is needed use NL_SET_ERR_MSG_FMT.
2d4bc933	96	*/
4d463c4d	97	#define NL_SET_ERR_MSG(extack, msg) do { \
6311b7ce	98	static const char __msg[] = msg; \
4d463c4d DB	99	struct netlink_ext_ack *__extack = (extack); \
4d463c4d DB	100	\
7e3ce05e MRL	101	do_trace_netlink_extack(__msg); \
7e3ce05e MRL	102	\
4d463c4d DB	103	if (__extack) \
4d463c4d DB	104	__extack->_msg = __msg; \
2d4bc933 JB	105	} while (0)
2d4bc933 JB	106
51c352bd EC	107	/* We splice fmt with %s at each end even in the snprintf so that both calls
	108	* can use the same string constant, avoiding its duplication in .ro
	109	*/
	110	#define NL_SET_ERR_MSG_FMT(extack, fmt, args...) do { \
	111	struct netlink_ext_ack *__extack = (extack); \
	112	\
	113	if (!__extack) \
	114	break; \
	115	if (snprintf(__extack->_msg_buf, NETLINK_MAX_FMTMSG_LEN, \
	116	"%s" fmt "%s", "", ##args, "") >= \
	117	NETLINK_MAX_FMTMSG_LEN) \
	118	net_warn_ratelimited("%s" fmt "%s", "truncated extack: ", \
	119	##args, "\n"); \
	120	\
	121	do_trace_netlink_extack(__extack->_msg_buf); \
	122	\
	123	__extack->_msg = __extack->_msg_buf; \
	124	} while (0)
	125
4d463c4d DB	126	#define NL_SET_ERR_MSG_MOD(extack, msg) \
4d463c4d DB	127	NL_SET_ERR_MSG((extack), KBUILD_MODNAME ": " msg)
45d9b378	128
51c352bd EC	129	#define NL_SET_ERR_MSG_FMT_MOD(extack, fmt, args...) \
	130	NL_SET_ERR_MSG_FMT((extack), KBUILD_MODNAME ": " fmt, ##args)
	131
028fb19c LR	132	#define NL_SET_ERR_MSG_WEAK(extack, msg) do { \
	133	if ((extack) && !(extack)->_msg) \
	134	NL_SET_ERR_MSG((extack), msg); \
	135	} while (0)
	136
	137	#define NL_SET_ERR_MSG_WEAK_MOD(extack, msg) do { \
	138	if ((extack) && !(extack)->_msg) \
	139	NL_SET_ERR_MSG_MOD((extack), msg); \
	140	} while (0)
	141
44f3625b JB	142	#define NL_SET_BAD_ATTR_POLICY(extack, attr, pol) do { \
44f3625b JB	143	if ((extack)) { \
c3ab2b4e	144	(extack)->bad_attr = (attr); \
44f3625b JB	145	(extack)->policy = (pol); \
44f3625b JB	146	} \
c3ab2b4e DA	147	} while (0)
c3ab2b4e DA	148
44f3625b JB	149	#define NL_SET_BAD_ATTR(extack, attr) NL_SET_BAD_ATTR_POLICY(extack, attr, NULL)
	150
	151	#define NL_SET_ERR_MSG_ATTR_POL(extack, attr, pol, msg) do { \
	152	static const char __msg[] = msg; \
	153	struct netlink_ext_ack *__extack = (extack); \
	154	\
7e3ce05e MRL	155	do_trace_netlink_extack(__msg); \
7e3ce05e MRL	156	\
44f3625b JB	157	if (__extack) { \
	158	__extack->_msg = __msg; \
	159	__extack->bad_attr = (attr); \
	160	__extack->policy = (pol); \
	161	} \
9ae28727 DA	162	} while (0)
9ae28727 DA	163
3e4d5ba9 SA	164	#define NL_SET_ERR_MSG_ATTR_POL_FMT(extack, attr, pol, fmt, args...) do { \
	165	struct netlink_ext_ack *__extack = (extack); \
	166	\
	167	if (!__extack) \
	168	break; \
	169	\
	170	if (snprintf(__extack->_msg_buf, NETLINK_MAX_FMTMSG_LEN, \
	171	"%s" fmt "%s", "", ##args, "") >= \
	172	NETLINK_MAX_FMTMSG_LEN) \
	173	net_warn_ratelimited("%s" fmt "%s", "truncated extack: ", \
	174	##args, "\n"); \
	175	\
	176	do_trace_netlink_extack(__extack->_msg_buf); \
	177	\
	178	__extack->_msg = __extack->_msg_buf; \
	179	__extack->bad_attr = (attr); \
	180	__extack->policy = (pol); \
	181	} while (0)
	182
44f3625b JB	183	#define NL_SET_ERR_MSG_ATTR(extack, attr, msg) \
	184	NL_SET_ERR_MSG_ATTR_POL(extack, attr, NULL, msg)
	185
3e4d5ba9 SA	186	#define NL_SET_ERR_MSG_ATTR_FMT(extack, attr, msg, args...) \
	187	NL_SET_ERR_MSG_ATTR_POL_FMT(extack, attr, NULL, msg, ##args)
	188
690252f1 JK	189	#define NL_SET_ERR_ATTR_MISS(extack, nest, type) do { \
	190	struct netlink_ext_ack *__extack = (extack); \
	191	\
	192	if (__extack) { \
	193	__extack->miss_nest = (nest); \
	194	__extack->miss_type = (type); \
	195	} \
	196	} while (0)
	197
45dca157 JK	198	#define NL_REQ_ATTR_CHECK(extack, nest, tb, type) ({ \
	199	struct nlattr **__tb = (tb); \
	200	u32 __attr = (type); \
	201	int __retval; \
	202	\
	203	__retval = !__tb[__attr]; \
	204	if (__retval) \
	205	NL_SET_ERR_ATTR_MISS((extack), (nest), __attr); \
	206	__retval; \
	207	})
	208
801f8746 JB	209	static inline void nl_set_extack_cookie_u64(struct netlink_ext_ack *extack,
	210	u64 cookie)
	211	{
55b474c4 MK	212	if (!extack)
55b474c4 MK	213	return;
c6400e3f AD	214	memcpy(extack->cookie, &cookie, sizeof(cookie));
c6400e3f AD	215	extack->cookie_len = sizeof(cookie);
801f8746 JB	216	}
801f8746 JB	217
aa9d6e0f SH	218	void netlink_kernel_release(struct sock *sk);
	219	int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
	220	int netlink_change_ngroups(struct sock *sk, unsigned int groups);
	221	void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
	222	void netlink_ack(struct sk_buff in_skb, struct nlmsghdr nlh, int err,
	223	const struct netlink_ext_ack *extack);
	224	int netlink_has_listeners(struct sock *sk, unsigned int group);
59c28058	225	bool netlink_strict_get_check(struct sk_buff *skb);
aa9d6e0f SH	226
	227	int netlink_unicast(struct sock ssk, struct sk_buff skb, __u32 portid, int nonblock);
	228	int netlink_broadcast(struct sock ssk, struct sk_buff skb, __u32 portid,
	229	__u32 group, gfp_t allocation);
aa9d6e0f SH	230	int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
	231	int netlink_register_notifier(struct notifier_block *nb);
	232	int netlink_unregister_notifier(struct notifier_block *nb);
1da177e4 LT	233
	234	/* finegrained unicast helpers: */
	235	struct sock netlink_getsockbyfilp(struct file filp);
9457afee	236	int netlink_attachskb(struct sock sk, struct sk_buff skb,
c3d8d1e3	237	long timeo, struct sock ssk);
1da177e4	238	void netlink_detachskb(struct sock sk, struct sk_buff skb);
7ee015e0	239	int netlink_sendskb(struct sock sk, struct sk_buff skb);
1da177e4	240
3a36515f PN	241	static inline struct sk_buff *
	242	netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
	243	{
	244	struct sk_buff *nskb;
	245
	246	nskb = skb_clone(skb, gfp_mask);
	247	if (!nskb)
	248	return NULL;
	249
	250	/* This is a large skb, set destructor callback to release head */
	251	if (is_vmalloc_addr(skb->head))
	252	nskb->destructor = skb->destructor;
	253
	254	return nskb;
	255	}
	256
1da177e4 LT	257	/*
1da177e4 LT	258	* skb should fit one page. This choice is good for headerless malloc.
fc910a27 DM	259	* But we should limit to 8K so that userspace does not have to
	260	* use enormous buffer sizes on recvmsg() calls just to avoid
	261	* MSG_TRUNC when PAGE_SIZE is very large.
1da177e4	262	*/
fc910a27 DM	263	#if PAGE_SIZE < 8192UL
	264	#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE)
	265	#else
	266	#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL)
	267	#endif
	268
339bf98f	269	#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
1da177e4 LT	270
1da177e4 LT	271
d94d9fee	272	struct netlink_callback {
3a6c2b41 PM	273	struct sk_buff *skb;
	274	const struct nlmsghdr *nlh;
	275	int (dump)(struct sk_buff skb,
	276	struct netlink_callback *cb);
	277	int (done)(struct netlink_callback cb);
7175c883	278	void *data;
6dc878a8 G	279	/* the module that dump function belong to */
6dc878a8 G	280	struct module *module;
4a19edb6	281	struct netlink_ext_ack *extack;
c7ac8679	282	u16 family;
22e6c58b	283	u16 answer_flags;
085c20ca	284	u32 min_dump_alloc;
670dc283	285	unsigned int prev_seq, seq;
085c20ca	286	bool strict_check;
362b87f5 JD	287	union {
	288	u8 ctx[48];
	289
	290	/* args is deprecated. Cast a struct over ctx instead
	291	* for proper type safety.
	292	*/
	293	long args[6];
	294	};
1da177e4 LT	295	};
1da177e4 LT	296
ec8f7d49	297	#define NL_ASSERT_DUMP_CTX_FITS(type_name) \
2c7bc10d JK	298	BUILD_BUG_ON(sizeof(type_name) > \
	299	sizeof_field(struct netlink_callback, ctx))
	300
d94d9fee	301	struct netlink_notify {
b4b51029	302	struct net *net;
0392d099	303	u32 portid;
1da177e4 LT	304	int protocol;
	305	};
	306
a46621a3	307	struct nlmsghdr *
15e47304	308	__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
1da177e4	309
80d326fa	310	struct netlink_dump_control {
fc9e50f5	311	int (start)(struct netlink_callback );
80d326fa	312	int (dump)(struct sk_buff skb, struct netlink_callback *);
6dc878a8	313	int (done)(struct netlink_callback );
7175c883	314	void *data;
6dc878a8	315	struct module *module;
ebfe3c51	316	u32 min_dump_alloc;
80d326fa PNA	317	};
80d326fa PNA	318
aa9d6e0f	319	int __netlink_dump_start(struct sock ssk, struct sk_buff skb,
6dc878a8 G	320	const struct nlmsghdr *nlh,
	321	struct netlink_dump_control *control);
	322	static inline int netlink_dump_start(struct sock ssk, struct sk_buff skb,
	323	const struct nlmsghdr *nlh,
	324	struct netlink_dump_control *control)
	325	{
	326	if (!control->module)
	327	control->module = THIS_MODULE;
	328
	329	return __netlink_dump_start(ssk, skb, nlh, control);
	330	}
1da177e4	331
bcbde0d4 DB	332	struct netlink_tap {
	333	struct net_device *dev;
	334	struct module *module;
	335	struct list_head list;
	336	};
	337
aa9d6e0f SH	338	int netlink_add_tap(struct netlink_tap *nt);
aa9d6e0f SH	339	int netlink_remove_tap(struct netlink_tap *nt);
bcbde0d4	340
aa4cf945 EB	341	bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
	342	struct user_namespace *ns, int cap);
	343	bool netlink_ns_capable(const struct sk_buff *skb,
	344	struct user_namespace *ns, int cap);
	345	bool netlink_capable(const struct sk_buff *skb, int cap);
	346	bool netlink_net_capable(const struct sk_buff *skb, int cap);
	347
1da177e4	348	#endif /* __LINUX_NETLINK_H */