1 files changed, 224 insertions, 37 deletions

diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 7a6c396a263b..882e9c1b6c1d 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __LINUX_NETLINK_H
 #define __LINUX_NETLINK_H
 
@@ -10,15 +11,15 @@
 
 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_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 {
@@ -27,14 +28,17 @@ struct netlink_skb_parms {
 	__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)
+#define NETLINK_CTX_SIZE	48
 
 
-extern void netlink_table_grab(void);
-extern void netlink_table_ungrab(void);
+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)
@@ -44,12 +48,12 @@ struct netlink_kernel_cfg {
 	unsigned int	groups;
 	unsigned int	flags;
 	void		(*input)(struct sk_buff *skb);
-	struct mutex	*cb_mutex;
-	void		(*bind)(int group);
-	bool		(*compare)(struct net *net, struct sock *sk);
+	int		(*bind)(struct net *net, int group);
+	void		(*unbind)(struct net *net, int group);
+	void            (*release) (struct sock *sk, unsigned long *groups);
 };
 
-extern struct sock *__netlink_kernel_create(struct net *net, int unit,
+struct sock *__netlink_kernel_create(struct net *net, int unit,
 					    struct module *module,
 					    struct netlink_kernel_cfg *cfg);
 static inline struct sock *
@@ -58,28 +62,186 @@ netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg)
 	return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
 }
 
-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_clear_multicast_users(struct sock *sk, unsigned int group);
-extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
-extern int netlink_has_listeners(struct sock *sk, unsigned int group);
-extern struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size,
-					 u32 dst_portid, gfp_t gfp_mask);
-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);
+/* this can be increased when necessary - don't expose to userland */
+#define NETLINK_MAX_COOKIE_LEN	8
+#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;
+	BUILD_BUG_ON(sizeof(extack->cookie) < sizeof(cookie));
+	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);
+
+typedef int (*netlink_filter_fn)(struct sock *dsk, struct sk_buff *skb, void *data);
+
+int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
+			       __u32 portid, __u32 group, gfp_t allocation,
+			       netlink_filter_fn filter,
+			       void *filter_data);
+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);
+struct sock *netlink_getsockbyfd(int fd);
 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);
@@ -125,15 +287,30 @@ struct netlink_callback {
 	void			*data;
 	/* the module that dump function belong to */
 	struct module		*module;
+	struct netlink_ext_ack	*extack;
 	u16			family;
-	u16			min_dump_alloc;
+	u16			answer_flags;
+	u32			min_dump_alloc;
 	unsigned int		prev_seq, seq;
-	long			args[6];
+	int			flags;
+	bool			strict_check;
+	union {
+		u8		ctx[NETLINK_CTX_SIZE];
+
+		/* args is deprecated. Cast a struct over ctx instead
+		 * for proper type safety.
+		 */
+		long		args[6];
+	};
 };
 
+#define NL_ASSERT_CTX_FITS(type_name)					\
+	BUILD_BUG_ON(sizeof(type_name) >				\
+		     sizeof_field(struct netlink_callback, ctx))
+
 struct netlink_notify {
 	struct net *net;
-	int portid;
+	u32 portid;
 	int protocol;
 };
 
@@ -141,14 +318,17 @@ 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 *);
+	struct netlink_ext_ack *extack;
 	void *data;
 	struct module *module;
-	u16 min_dump_alloc;
+	u32 min_dump_alloc;
+	int flags;
 };
 
-extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
+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,
@@ -167,8 +347,15 @@ struct netlink_tap {
 	struct list_head list;
 };
 
-extern int netlink_add_tap(struct netlink_tap *nt);
-extern int __netlink_remove_tap(struct netlink_tap *nt);
-extern int netlink_remove_tap(struct netlink_tap *nt);
+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);
+struct sk_buff *netlink_alloc_large_skb(unsigned int size, int broadcast);
 
 #endif	/* __LINUX_NETLINK_H */