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442 lines
13 KiB
442 lines
13 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
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#ifndef __NET_GENERIC_NETLINK_H |
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#define __NET_GENERIC_NETLINK_H |
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#include <linux/genetlink.h> |
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#include <net/netlink.h> |
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#include <net/net_namespace.h> |
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#define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN) |
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/** |
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* struct genl_multicast_group - generic netlink multicast group |
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* @name: name of the multicast group, names are per-family |
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*/ |
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struct genl_multicast_group { |
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char name[GENL_NAMSIZ]; |
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u8 flags; |
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}; |
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struct genl_ops; |
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struct genl_info; |
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/** |
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* struct genl_family - generic netlink family |
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* @id: protocol family identifier (private) |
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* @hdrsize: length of user specific header in bytes |
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* @name: name of family |
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* @version: protocol version |
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* @maxattr: maximum number of attributes supported |
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* @policy: netlink policy |
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* @netnsok: set to true if the family can handle network |
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* namespaces and should be presented in all of them |
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* @parallel_ops: operations can be called in parallel and aren't |
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* synchronized by the core genetlink code |
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* @pre_doit: called before an operation's doit callback, it may |
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* do additional, common, filtering and return an error |
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* @post_doit: called after an operation's doit callback, it may |
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* undo operations done by pre_doit, for example release locks |
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* @mcgrps: multicast groups used by this family |
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* @n_mcgrps: number of multicast groups |
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* @mcgrp_offset: starting number of multicast group IDs in this family |
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* (private) |
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* @ops: the operations supported by this family |
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* @n_ops: number of operations supported by this family |
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* @small_ops: the small-struct operations supported by this family |
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* @n_small_ops: number of small-struct operations supported by this family |
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*/ |
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struct genl_family { |
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int id; /* private */ |
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unsigned int hdrsize; |
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char name[GENL_NAMSIZ]; |
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unsigned int version; |
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unsigned int maxattr; |
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unsigned int mcgrp_offset; /* private */ |
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u8 netnsok:1; |
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u8 parallel_ops:1; |
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u8 n_ops; |
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u8 n_small_ops; |
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u8 n_mcgrps; |
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const struct nla_policy *policy; |
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int (*pre_doit)(const struct genl_ops *ops, |
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struct sk_buff *skb, |
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struct genl_info *info); |
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void (*post_doit)(const struct genl_ops *ops, |
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struct sk_buff *skb, |
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struct genl_info *info); |
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const struct genl_ops * ops; |
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const struct genl_small_ops *small_ops; |
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const struct genl_multicast_group *mcgrps; |
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struct module *module; |
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}; |
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/** |
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* struct genl_info - receiving information |
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* @snd_seq: sending sequence number |
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* @snd_portid: netlink portid of sender |
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* @nlhdr: netlink message header |
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* @genlhdr: generic netlink message header |
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* @userhdr: user specific header |
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* @attrs: netlink attributes |
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* @_net: network namespace |
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* @user_ptr: user pointers |
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* @extack: extended ACK report struct |
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*/ |
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struct genl_info { |
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u32 snd_seq; |
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u32 snd_portid; |
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struct nlmsghdr * nlhdr; |
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struct genlmsghdr * genlhdr; |
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void * userhdr; |
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struct nlattr ** attrs; |
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possible_net_t _net; |
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void * user_ptr[2]; |
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struct netlink_ext_ack *extack; |
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}; |
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static inline struct net *genl_info_net(struct genl_info *info) |
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{ |
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return read_pnet(&info->_net); |
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} |
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static inline void genl_info_net_set(struct genl_info *info, struct net *net) |
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{ |
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write_pnet(&info->_net, net); |
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} |
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#define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg) |
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enum genl_validate_flags { |
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GENL_DONT_VALIDATE_STRICT = BIT(0), |
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GENL_DONT_VALIDATE_DUMP = BIT(1), |
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GENL_DONT_VALIDATE_DUMP_STRICT = BIT(2), |
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}; |
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/** |
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* struct genl_small_ops - generic netlink operations (small version) |
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* @cmd: command identifier |
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* @internal_flags: flags used by the family |
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* @flags: flags |
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* @validate: validation flags from enum genl_validate_flags |
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* @doit: standard command callback |
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* @dumpit: callback for dumpers |
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* |
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* This is a cut-down version of struct genl_ops for users who don't need |
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* most of the ancillary infra and want to save space. |
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*/ |
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struct genl_small_ops { |
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int (*doit)(struct sk_buff *skb, struct genl_info *info); |
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int (*dumpit)(struct sk_buff *skb, struct netlink_callback *cb); |
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u8 cmd; |
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u8 internal_flags; |
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u8 flags; |
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u8 validate; |
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}; |
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/** |
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* struct genl_ops - generic netlink operations |
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* @cmd: command identifier |
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* @internal_flags: flags used by the family |
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* @flags: flags |
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* @maxattr: maximum number of attributes supported |
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* @policy: netlink policy (takes precedence over family policy) |
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* @validate: validation flags from enum genl_validate_flags |
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* @doit: standard command callback |
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* @start: start callback for dumps |
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* @dumpit: callback for dumpers |
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* @done: completion callback for dumps |
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*/ |
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struct genl_ops { |
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int (*doit)(struct sk_buff *skb, |
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struct genl_info *info); |
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int (*start)(struct netlink_callback *cb); |
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int (*dumpit)(struct sk_buff *skb, |
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struct netlink_callback *cb); |
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int (*done)(struct netlink_callback *cb); |
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const struct nla_policy *policy; |
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unsigned int maxattr; |
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u8 cmd; |
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u8 internal_flags; |
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u8 flags; |
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u8 validate; |
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}; |
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/** |
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* struct genl_info - info that is available during dumpit op call |
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* @family: generic netlink family - for internal genl code usage |
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* @ops: generic netlink ops - for internal genl code usage |
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* @attrs: netlink attributes |
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*/ |
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struct genl_dumpit_info { |
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const struct genl_family *family; |
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struct genl_ops op; |
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struct nlattr **attrs; |
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}; |
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static inline const struct genl_dumpit_info * |
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genl_dumpit_info(struct netlink_callback *cb) |
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{ |
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return cb->data; |
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} |
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int genl_register_family(struct genl_family *family); |
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int genl_unregister_family(const struct genl_family *family); |
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void genl_notify(const struct genl_family *family, struct sk_buff *skb, |
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struct genl_info *info, u32 group, gfp_t flags); |
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void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, |
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const struct genl_family *family, int flags, u8 cmd); |
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/** |
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* genlmsg_nlhdr - Obtain netlink header from user specified header |
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* @user_hdr: user header as returned from genlmsg_put() |
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* |
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* Returns pointer to netlink header. |
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*/ |
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static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr) |
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{ |
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return (struct nlmsghdr *)((char *)user_hdr - |
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GENL_HDRLEN - |
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NLMSG_HDRLEN); |
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} |
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/** |
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* genlmsg_parse_deprecated - parse attributes of a genetlink message |
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* @nlh: netlink message header |
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* @family: genetlink message family |
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* @tb: destination array with maxtype+1 elements |
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* @maxtype: maximum attribute type to be expected |
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* @policy: validation policy |
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* @extack: extended ACK report struct |
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*/ |
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static inline int genlmsg_parse_deprecated(const struct nlmsghdr *nlh, |
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const struct genl_family *family, |
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struct nlattr *tb[], int maxtype, |
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const struct nla_policy *policy, |
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struct netlink_ext_ack *extack) |
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{ |
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return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype, |
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policy, NL_VALIDATE_LIBERAL, extack); |
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} |
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/** |
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* genlmsg_parse - parse attributes of a genetlink message |
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* @nlh: netlink message header |
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* @family: genetlink message family |
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* @tb: destination array with maxtype+1 elements |
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* @maxtype: maximum attribute type to be expected |
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* @policy: validation policy |
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* @extack: extended ACK report struct |
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*/ |
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static inline int genlmsg_parse(const struct nlmsghdr *nlh, |
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const struct genl_family *family, |
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struct nlattr *tb[], int maxtype, |
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const struct nla_policy *policy, |
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struct netlink_ext_ack *extack) |
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{ |
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return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype, |
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policy, NL_VALIDATE_STRICT, extack); |
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} |
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/** |
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* genl_dump_check_consistent - check if sequence is consistent and advertise if not |
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* @cb: netlink callback structure that stores the sequence number |
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* @user_hdr: user header as returned from genlmsg_put() |
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* |
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* Cf. nl_dump_check_consistent(), this just provides a wrapper to make it |
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* simpler to use with generic netlink. |
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*/ |
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static inline void genl_dump_check_consistent(struct netlink_callback *cb, |
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void *user_hdr) |
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{ |
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nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr)); |
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} |
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/** |
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* genlmsg_put_reply - Add generic netlink header to a reply message |
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* @skb: socket buffer holding the message |
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* @info: receiver info |
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* @family: generic netlink family |
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* @flags: netlink message flags |
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* @cmd: generic netlink command |
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* |
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* Returns pointer to user specific header |
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*/ |
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static inline void *genlmsg_put_reply(struct sk_buff *skb, |
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struct genl_info *info, |
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const struct genl_family *family, |
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int flags, u8 cmd) |
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{ |
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return genlmsg_put(skb, info->snd_portid, info->snd_seq, family, |
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flags, cmd); |
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} |
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/** |
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* genlmsg_end - Finalize a generic netlink message |
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* @skb: socket buffer the message is stored in |
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* @hdr: user specific header |
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*/ |
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static inline void genlmsg_end(struct sk_buff *skb, void *hdr) |
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{ |
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nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); |
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} |
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/** |
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* genlmsg_cancel - Cancel construction of a generic netlink message |
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* @skb: socket buffer the message is stored in |
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* @hdr: generic netlink message header |
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*/ |
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static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr) |
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{ |
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if (hdr) |
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nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); |
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} |
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/** |
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* genlmsg_multicast_netns - multicast a netlink message to a specific netns |
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* @family: the generic netlink family |
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* @net: the net namespace |
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* @skb: netlink message as socket buffer |
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* @portid: own netlink portid to avoid sending to yourself |
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* @group: offset of multicast group in groups array |
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* @flags: allocation flags |
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*/ |
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static inline int genlmsg_multicast_netns(const struct genl_family *family, |
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struct net *net, struct sk_buff *skb, |
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u32 portid, unsigned int group, gfp_t flags) |
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{ |
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if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
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return -EINVAL; |
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group = family->mcgrp_offset + group; |
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return nlmsg_multicast(net->genl_sock, skb, portid, group, flags); |
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} |
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/** |
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* genlmsg_multicast - multicast a netlink message to the default netns |
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* @family: the generic netlink family |
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* @skb: netlink message as socket buffer |
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* @portid: own netlink portid to avoid sending to yourself |
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* @group: offset of multicast group in groups array |
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* @flags: allocation flags |
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*/ |
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static inline int genlmsg_multicast(const struct genl_family *family, |
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struct sk_buff *skb, u32 portid, |
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unsigned int group, gfp_t flags) |
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{ |
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return genlmsg_multicast_netns(family, &init_net, skb, |
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portid, group, flags); |
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} |
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/** |
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* genlmsg_multicast_allns - multicast a netlink message to all net namespaces |
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* @family: the generic netlink family |
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* @skb: netlink message as socket buffer |
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* @portid: own netlink portid to avoid sending to yourself |
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* @group: offset of multicast group in groups array |
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* @flags: allocation flags |
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* |
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* This function must hold the RTNL or rcu_read_lock(). |
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*/ |
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int genlmsg_multicast_allns(const struct genl_family *family, |
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struct sk_buff *skb, u32 portid, |
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unsigned int group, gfp_t flags); |
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/** |
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* genlmsg_unicast - unicast a netlink message |
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* @skb: netlink message as socket buffer |
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* @portid: netlink portid of the destination socket |
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*/ |
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static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid) |
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{ |
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return nlmsg_unicast(net->genl_sock, skb, portid); |
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} |
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/** |
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* genlmsg_reply - reply to a request |
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* @skb: netlink message to be sent back |
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* @info: receiver information |
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*/ |
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static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info) |
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{ |
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return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid); |
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} |
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/** |
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* gennlmsg_data - head of message payload |
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* @gnlh: genetlink message header |
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*/ |
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static inline void *genlmsg_data(const struct genlmsghdr *gnlh) |
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{ |
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return ((unsigned char *) gnlh + GENL_HDRLEN); |
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} |
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/** |
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* genlmsg_len - length of message payload |
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* @gnlh: genetlink message header |
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*/ |
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static inline int genlmsg_len(const struct genlmsghdr *gnlh) |
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{ |
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struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh - |
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NLMSG_HDRLEN); |
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return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN); |
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} |
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/** |
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* genlmsg_msg_size - length of genetlink message not including padding |
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* @payload: length of message payload |
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*/ |
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static inline int genlmsg_msg_size(int payload) |
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{ |
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return GENL_HDRLEN + payload; |
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} |
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/** |
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* genlmsg_total_size - length of genetlink message including padding |
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* @payload: length of message payload |
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*/ |
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static inline int genlmsg_total_size(int payload) |
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{ |
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return NLMSG_ALIGN(genlmsg_msg_size(payload)); |
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} |
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/** |
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* genlmsg_new - Allocate a new generic netlink message |
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* @payload: size of the message payload |
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* @flags: the type of memory to allocate. |
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*/ |
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static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags) |
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{ |
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return nlmsg_new(genlmsg_total_size(payload), flags); |
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} |
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/** |
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* genl_set_err - report error to genetlink broadcast listeners |
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* @family: the generic netlink family |
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* @net: the network namespace to report the error to |
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* @portid: the PORTID of a process that we want to skip (if any) |
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* @group: the broadcast group that will notice the error |
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* (this is the offset of the multicast group in the groups array) |
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* @code: error code, must be negative (as usual in kernelspace) |
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* |
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* This function returns the number of broadcast listeners that have set the |
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* NETLINK_RECV_NO_ENOBUFS socket option. |
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*/ |
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static inline int genl_set_err(const struct genl_family *family, |
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struct net *net, u32 portid, |
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u32 group, int code) |
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{ |
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if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
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return -EINVAL; |
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group = family->mcgrp_offset + group; |
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return netlink_set_err(net->genl_sock, portid, group, code); |
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} |
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static inline int genl_has_listeners(const struct genl_family *family, |
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struct net *net, unsigned int group) |
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{ |
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if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
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return -EINVAL; |
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group = family->mcgrp_offset + group; |
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return netlink_has_listeners(net->genl_sock, group); |
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} |
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#endif /* __NET_GENERIC_NETLINK_H */
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