1 files changed, 288 insertions, 0 deletions
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
new file mode 100644
index 000000000..d51e041d2
--- /dev/null
+++ b/include/linux/netlink.h
@@ -0,0 +1,288 @@
+/* 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);
+	bool		(*compare)(struct net *net, struct sock *sk);
+};
+
+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
+ * @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
+ */
+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;
+};
+
+/* 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);	\
+							\
+	do_trace_netlink_extack(__msg);			\
+							\
+	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_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(extack, attr, msg)		\
+	NL_SET_ERR_MSG_ATTR_POL(extack, attr, NULL, msg)
+
+#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];
+	};
+};
+
+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 */