| /* 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 |
| * @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); |
| 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 */ |