v4.19.13 snapshot.
diff --git a/include/net/genetlink.h b/include/net/genetlink.h
new file mode 100644
index 0000000..decf601
--- /dev/null
+++ b/include/net/genetlink.h
@@ -0,0 +1,387 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#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 identifier (private)
+ * @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 (private)
+ * @mcgrps: multicast groups used by this family
+ * @n_mcgrps: number of multicast groups
+ * @mcgrp_offset: starting number of multicast group IDs in this family
+ * (private)
+ * @ops: the operations supported by this family
+ * @n_ops: number of operations supported by this family
+ */
+struct genl_family {
+ int id; /* private */
+ 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;
+ const struct genl_multicast_group *mcgrps;
+ unsigned int n_ops;
+ unsigned int n_mcgrps;
+ unsigned int mcgrp_offset; /* private */
+ struct module *module;
+};
+
+struct nlattr **genl_family_attrbuf(const struct genl_family *family);
+
+/**
+ * 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
+ * @extack: extended ACK report struct
+ */
+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 netlink_ext_ack *extack;
+};
+
+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);
+}
+
+#define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg)
+
+static inline int genl_err_attr(struct genl_info *info, int err,
+ struct nlattr *attr)
+{
+ info->extack->bad_attr = attr;
+
+ return err;
+}
+
+/**
+ * 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
+ * @start: start callback for dumps
+ * @dumpit: callback for dumpers
+ * @done: completion callback for dumps
+ */
+struct genl_ops {
+ const struct nla_policy *policy;
+ int (*doit)(struct sk_buff *skb,
+ struct genl_info *info);
+ int (*start)(struct netlink_callback *cb);
+ 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);
+int genl_unregister_family(const struct genl_family *family);
+void genl_notify(const struct genl_family *family, struct sk_buff *skb,
+ struct genl_info *info, u32 group, gfp_t flags);
+
+void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
+ const 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()
+ *
+ * Returns pointer to netlink header.
+ */
+static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr)
+{
+ return (struct nlmsghdr *)((char *)user_hdr -
+ 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
+ * @extack: extended ACK report struct
+ */
+static inline int genlmsg_parse(const struct nlmsghdr *nlh,
+ const struct genl_family *family,
+ struct nlattr *tb[], int maxtype,
+ const struct nla_policy *policy,
+ struct netlink_ext_ack *extack)
+{
+ return nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
+ policy, extack);
+}
+
+/**
+ * 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()
+ *
+ * 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)
+{
+ nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr));
+}
+
+/**
+ * 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,
+ const 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(const 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(const 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(const 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(const 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(const 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 */