Initial import

1 files changed, 430 insertions, 0 deletions

diff --git a/include/net/genetlink.h b/include/net/genetlink.h
new file mode 100644
index 000000000..a9af1cc8c
--- /dev/null
+++ b/include/net/genetlink.h
@@ -0,0 +1,430 @@
+#ifndef __NET_GENERIC_NETLINK_H
+#define __NET_GENERIC_NETLINK_H
+
+#include <linux/genetlink.h>
+#include <net/netlink.h>
+#include <net/net_namespace.h>
+
+#define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN)
+
+/**
+ * struct genl_multicast_group - generic netlink multicast group
+ * @name: name of the multicast group, names are per-family
+ */
+struct genl_multicast_group {
+	char			name[GENL_NAMSIZ];
+};
+
+struct genl_ops;
+struct genl_info;
+
+/**
+ * struct genl_family - generic netlink family
+ * @id: protocol family idenfitier
+ * @hdrsize: length of user specific header in bytes
+ * @name: name of family
+ * @version: protocol version
+ * @maxattr: maximum number of attributes supported
+ * @netnsok: set to true if the family can handle network
+ *	namespaces and should be presented in all of them
+ * @parallel_ops: operations can be called in parallel and aren't
+ *	synchronized by the core genetlink code
+ * @pre_doit: called before an operation's doit callback, it may
+ *	do additional, common, filtering and return an error
+ * @post_doit: called after an operation's doit callback, it may
+ *	undo operations done by pre_doit, for example release locks
+ * @mcast_bind: a socket bound to the given multicast group (which
+ *	is given as the offset into the groups array)
+ * @mcast_unbind: a socket was unbound from the given multicast group.
+ *	Note that unbind() will not be called symmetrically if the
+ *	generic netlink family is removed while there are still open
+ *	sockets.
+ * @attrbuf: buffer to store parsed attributes
+ * @family_list: family list
+ * @mcgrps: multicast groups used by this family (private)
+ * @n_mcgrps: number of multicast groups (private)
+ * @mcgrp_offset: starting number of multicast group IDs in this family
+ * @ops: the operations supported by this family (private)
+ * @n_ops: number of operations supported by this family (private)
+ */
+struct genl_family {
+	unsigned int		id;
+	unsigned int		hdrsize;
+	char			name[GENL_NAMSIZ];
+	unsigned int		version;
+	unsigned int		maxattr;
+	bool			netnsok;
+	bool			parallel_ops;
+	int			(*pre_doit)(const struct genl_ops *ops,
+					    struct sk_buff *skb,
+					    struct genl_info *info);
+	void			(*post_doit)(const struct genl_ops *ops,
+					     struct sk_buff *skb,
+					     struct genl_info *info);
+	int			(*mcast_bind)(struct net *net, int group);
+	void			(*mcast_unbind)(struct net *net, int group);
+	struct nlattr **	attrbuf;	/* private */
+	const struct genl_ops *	ops;		/* private */
+	const struct genl_multicast_group *mcgrps; /* private */
+	unsigned int		n_ops;		/* private */
+	unsigned int		n_mcgrps;	/* private */
+	unsigned int		mcgrp_offset;	/* private */
+	struct list_head	family_list;	/* private */
+	struct module		*module;
+};
+
+/**
+ * struct genl_info - receiving information
+ * @snd_seq: sending sequence number
+ * @snd_portid: netlink portid of sender
+ * @nlhdr: netlink message header
+ * @genlhdr: generic netlink message header
+ * @userhdr: user specific header
+ * @attrs: netlink attributes
+ * @_net: network namespace
+ * @user_ptr: user pointers
+ * @dst_sk: destination socket
+ */
+struct genl_info {
+	u32			snd_seq;
+	u32			snd_portid;
+	struct nlmsghdr *	nlhdr;
+	struct genlmsghdr *	genlhdr;
+	void *			userhdr;
+	struct nlattr **	attrs;
+	possible_net_t		_net;
+	void *			user_ptr[2];
+	struct sock *		dst_sk;
+};
+
+static inline struct net *genl_info_net(struct genl_info *info)
+{
+	return read_pnet(&info->_net);
+}
+
+static inline void genl_info_net_set(struct genl_info *info, struct net *net)
+{
+	write_pnet(&info->_net, net);
+}
+
+/**
+ * struct genl_ops - generic netlink operations
+ * @cmd: command identifier
+ * @internal_flags: flags used by the family
+ * @flags: flags
+ * @policy: attribute validation policy
+ * @doit: standard command callback
+ * @dumpit: callback for dumpers
+ * @done: completion callback for dumps
+ * @ops_list: operations list
+ */
+struct genl_ops {
+	const struct nla_policy	*policy;
+	int		       (*doit)(struct sk_buff *skb,
+				       struct genl_info *info);
+	int		       (*dumpit)(struct sk_buff *skb,
+					 struct netlink_callback *cb);
+	int		       (*done)(struct netlink_callback *cb);
+	u8			cmd;
+	u8			internal_flags;
+	u8			flags;
+};
+
+int __genl_register_family(struct genl_family *family);
+
+static inline int genl_register_family(struct genl_family *family)
+{
+	family->module = THIS_MODULE;
+	return __genl_register_family(family);
+}
+
+/**
+ * genl_register_family_with_ops - register a generic netlink family with ops
+ * @family: generic netlink family
+ * @ops: operations to be registered
+ * @n_ops: number of elements to register
+ *
+ * Registers the specified family and operations from the specified table.
+ * Only one family may be registered with the same family name or identifier.
+ *
+ * The family id may equal GENL_ID_GENERATE causing an unique id to
+ * be automatically generated and assigned.
+ *
+ * Either a doit or dumpit callback must be specified for every registered
+ * operation or the function will fail. Only one operation structure per
+ * command identifier may be registered.
+ *
+ * See include/net/genetlink.h for more documenation on the operations
+ * structure.
+ *
+ * Return 0 on success or a negative error code.
+ */
+static inline int
+_genl_register_family_with_ops_grps(struct genl_family *family,
+				    const struct genl_ops *ops, size_t n_ops,
+				    const struct genl_multicast_group *mcgrps,
+				    size_t n_mcgrps)
+{
+	family->module = THIS_MODULE;
+	family->ops = ops;
+	family->n_ops = n_ops;
+	family->mcgrps = mcgrps;
+	family->n_mcgrps = n_mcgrps;
+	return __genl_register_family(family);
+}
+
+#define genl_register_family_with_ops(family, ops)			\
+	_genl_register_family_with_ops_grps((family),			\
+					    (ops), ARRAY_SIZE(ops),	\
+					    NULL, 0)
+#define genl_register_family_with_ops_groups(family, ops, grps)	\
+	_genl_register_family_with_ops_grps((family),			\
+					    (ops), ARRAY_SIZE(ops),	\
+					    (grps), ARRAY_SIZE(grps))
+
+int genl_unregister_family(struct genl_family *family);
+void genl_notify(struct genl_family *family,
+		 struct sk_buff *skb, struct net *net, u32 portid,
+		 u32 group, struct nlmsghdr *nlh, gfp_t flags);
+
+struct sk_buff *genlmsg_new_unicast(size_t payload, struct genl_info *info,
+				    gfp_t flags);
+void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
+		  struct genl_family *family, int flags, u8 cmd);
+
+/**
+ * genlmsg_nlhdr - Obtain netlink header from user specified header
+ * @user_hdr: user header as returned from genlmsg_put()
+ * @family: generic netlink family
+ *
+ * Returns pointer to netlink header.
+ */
+static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr,
+					     struct genl_family *family)
+{
+	return (struct nlmsghdr *)((char *)user_hdr -
+				   family->hdrsize -
+				   GENL_HDRLEN -
+				   NLMSG_HDRLEN);
+}
+
+/**
+ * genlmsg_parse - parse attributes of a genetlink message
+ * @nlh: netlink message header
+ * @family: genetlink message family
+ * @tb: destination array with maxtype+1 elements
+ * @maxtype: maximum attribute type to be expected
+ * @policy: validation policy
+ * */
+static inline int genlmsg_parse(const struct nlmsghdr *nlh,
+				const struct genl_family *family,
+				struct nlattr *tb[], int maxtype,
+				const struct nla_policy *policy)
+{
+	return nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
+			   policy);
+}
+
+/**
+ * genl_dump_check_consistent - check if sequence is consistent and advertise if not
+ * @cb: netlink callback structure that stores the sequence number
+ * @user_hdr: user header as returned from genlmsg_put()
+ * @family: generic netlink family
+ *
+ * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
+ * simpler to use with generic netlink.
+ */
+static inline void genl_dump_check_consistent(struct netlink_callback *cb,
+					      void *user_hdr,
+					      struct genl_family *family)
+{
+	nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family));
+}
+
+/**
+ * genlmsg_put_reply - Add generic netlink header to a reply message
+ * @skb: socket buffer holding the message
+ * @info: receiver info
+ * @family: generic netlink family
+ * @flags: netlink message flags
+ * @cmd: generic netlink command
+ *
+ * Returns pointer to user specific header
+ */
+static inline void *genlmsg_put_reply(struct sk_buff *skb,
+				      struct genl_info *info,
+				      struct genl_family *family,
+				      int flags, u8 cmd)
+{
+	return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
+			   flags, cmd);
+}
+
+/**
+ * genlmsg_end - Finalize a generic netlink message
+ * @skb: socket buffer the message is stored in
+ * @hdr: user specific header
+ */
+static inline void genlmsg_end(struct sk_buff *skb, void *hdr)
+{
+	nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
+}
+
+/**
+ * genlmsg_cancel - Cancel construction of a generic netlink message
+ * @skb: socket buffer the message is stored in
+ * @hdr: generic netlink message header
+ */
+static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
+{
+	if (hdr)
+		nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
+}
+
+/**
+ * genlmsg_multicast_netns - multicast a netlink message to a specific netns
+ * @family: the generic netlink family
+ * @net: the net namespace
+ * @skb: netlink message as socket buffer
+ * @portid: own netlink portid to avoid sending to yourself
+ * @group: offset of multicast group in groups array
+ * @flags: allocation flags
+ */
+static inline int genlmsg_multicast_netns(struct genl_family *family,
+					  struct net *net, struct sk_buff *skb,
+					  u32 portid, unsigned int group, gfp_t flags)
+{
+	if (WARN_ON_ONCE(group >= family->n_mcgrps))
+		return -EINVAL;
+	group = family->mcgrp_offset + group;
+	return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
+}
+
+/**
+ * genlmsg_multicast - multicast a netlink message to the default netns
+ * @family: the generic netlink family
+ * @skb: netlink message as socket buffer
+ * @portid: own netlink portid to avoid sending to yourself
+ * @group: offset of multicast group in groups array
+ * @flags: allocation flags
+ */
+static inline int genlmsg_multicast(struct genl_family *family,
+				    struct sk_buff *skb, u32 portid,
+				    unsigned int group, gfp_t flags)
+{
+	return genlmsg_multicast_netns(family, &init_net, skb,
+				       portid, group, flags);
+}
+
+/**
+ * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
+ * @family: the generic netlink family
+ * @skb: netlink message as socket buffer
+ * @portid: own netlink portid to avoid sending to yourself
+ * @group: offset of multicast group in groups array
+ * @flags: allocation flags
+ *
+ * This function must hold the RTNL or rcu_read_lock().
+ */
+int genlmsg_multicast_allns(struct genl_family *family,
+			    struct sk_buff *skb, u32 portid,
+			    unsigned int group, gfp_t flags);
+
+/**
+ * genlmsg_unicast - unicast a netlink message
+ * @skb: netlink message as socket buffer
+ * @portid: netlink portid of the destination socket
+ */
+static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
+{
+	return nlmsg_unicast(net->genl_sock, skb, portid);
+}
+
+/**
+ * genlmsg_reply - reply to a request
+ * @skb: netlink message to be sent back
+ * @info: receiver information
+ */
+static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
+{
+	return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
+}
+
+/**
+ * gennlmsg_data - head of message payload
+ * @gnlh: genetlink message header
+ */
+static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
+{
+	return ((unsigned char *) gnlh + GENL_HDRLEN);
+}
+
+/**
+ * genlmsg_len - length of message payload
+ * @gnlh: genetlink message header
+ */
+static inline int genlmsg_len(const struct genlmsghdr *gnlh)
+{
+	struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
+							NLMSG_HDRLEN);
+	return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
+}
+
+/**
+ * genlmsg_msg_size - length of genetlink message not including padding
+ * @payload: length of message payload
+ */
+static inline int genlmsg_msg_size(int payload)
+{
+	return GENL_HDRLEN + payload;
+}
+
+/**
+ * genlmsg_total_size - length of genetlink message including padding
+ * @payload: length of message payload
+ */
+static inline int genlmsg_total_size(int payload)
+{
+	return NLMSG_ALIGN(genlmsg_msg_size(payload));
+}
+
+/**
+ * genlmsg_new - Allocate a new generic netlink message
+ * @payload: size of the message payload
+ * @flags: the type of memory to allocate.
+ */
+static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
+{
+	return nlmsg_new(genlmsg_total_size(payload), flags);
+}
+
+/**
+ * genl_set_err - report error to genetlink broadcast listeners
+ * @family: the generic netlink family
+ * @net: the network namespace to report the error to
+ * @portid: the PORTID of a process that we want to skip (if any)
+ * @group: the broadcast group that will notice the error
+ * 	(this is the offset of the multicast group in the groups array)
+ * @code: error code, must be negative (as usual in kernelspace)
+ *
+ * This function returns the number of broadcast listeners that have set the
+ * NETLINK_RECV_NO_ENOBUFS socket option.
+ */
+static inline int genl_set_err(struct genl_family *family, struct net *net,
+			       u32 portid, u32 group, int code)
+{
+	if (WARN_ON_ONCE(group >= family->n_mcgrps))
+		return -EINVAL;
+	group = family->mcgrp_offset + group;
+	return netlink_set_err(net->genl_sock, portid, group, code);
+}
+
+static inline int genl_has_listeners(struct genl_family *family,
+				     struct net *net, unsigned int group)
+{
+	if (WARN_ON_ONCE(group >= family->n_mcgrps))
+		return -EINVAL;
+	group = family->mcgrp_offset + group;
+	return netlink_has_listeners(net->genl_sock, group);
+}
+#endif	/* __NET_GENERIC_NETLINK_H */