/include/net/genetlink.h
C Header | 405 lines | 197 code | 35 blank | 173 comment | 4 complexity | 1fc6661cffc9e0496ee34de9d11df695 MD5 | raw file
- /* 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
- * @policy: netlink policy
- * @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
- * @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;
- const struct nla_policy *policy;
- 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);
- 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,
- const struct nlattr *attr)
- {
- info->extack->bad_attr = attr;
- return err;
- }
- enum genl_validate_flags {
- GENL_DONT_VALIDATE_STRICT = BIT(0),
- GENL_DONT_VALIDATE_DUMP = BIT(1),
- GENL_DONT_VALIDATE_DUMP_STRICT = BIT(2),
- };
- /**
- * struct genl_ops - generic netlink operations
- * @cmd: command identifier
- * @internal_flags: flags used by the family
- * @flags: flags
- * @doit: standard command callback
- * @start: start callback for dumps
- * @dumpit: callback for dumpers
- * @done: completion callback for dumps
- */
- struct genl_ops {
- 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;
- u8 validate;
- };
- 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_deprecated - 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_deprecated(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, NL_VALIDATE_LIBERAL, extack);
- }
- /**
- * 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, NL_VALIDATE_STRICT, 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 */