![Johannes Berg](/assets/img/avatar_default.png)
This makes generic netlink network namespace aware. No generic netlink families except for the controller family are made namespace aware, they need to be checked one by one and then set the family->netnsok member to true. A new function genlmsg_multicast_netns() is introduced to allow sending a multicast message in a given namespace, for example when it applies to an object that lives in that namespace, a new function genlmsg_multicast_allns() to send a message to all network namespaces (for objects that do not have an associated netns). The function genlmsg_multicast() is changed to multicast the message in just init_net, which is currently correct for all generic netlink families since they only work in init_net right now. Some will later want to work in all net namespaces because they do not care about the netns at all -- those will have to be converted to use one of the new functions genlmsg_multicast_allns() or genlmsg_multicast_netns() whenever they are made netns aware in some way. After this patch families can easily decide whether or not they should be available in all net namespaces. Many genl families us it for objects not related to networking and should therefore be available in all namespaces, but that will have to be done on a per family basis. Note that this doesn't touch on the checkpoint/restart problem where network namespaces could be used, genl families and multicast groups are numbered globally and I see no easy way of changing that, especially since it must be possible to multicast to all network namespaces for those families that do not care about netns. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
307 lines
8.3 KiB
C
307 lines
8.3 KiB
C
#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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/**
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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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* @id: multicast group ID, assigned by the core, to use with
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* genlmsg_multicast().
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* @list: list entry for linking
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* @family: pointer to family, need not be set before registering
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*/
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struct genl_multicast_group
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{
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struct genl_family *family; /* private */
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struct list_head list; /* private */
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char name[GENL_NAMSIZ];
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u32 id;
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};
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/**
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* struct genl_family - generic netlink family
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* @id: protocol family idenfitier
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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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* @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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* @attrbuf: buffer to store parsed attributes
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* @ops_list: list of all assigned operations
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* @family_list: family list
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* @mcast_groups: multicast groups list
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*/
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struct genl_family
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{
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unsigned int id;
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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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bool netnsok;
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struct nlattr ** attrbuf; /* private */
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struct list_head ops_list; /* private */
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struct list_head family_list; /* private */
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struct list_head mcast_groups; /* private */
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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_pid: netlink pid 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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*/
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struct genl_info
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{
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u32 snd_seq;
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u32 snd_pid;
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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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#ifdef CONFIG_NET_NS
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struct net * _net;
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#endif
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};
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#ifdef CONFIG_NET_NS
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static inline struct net *genl_info_net(struct genl_info *info)
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{
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return 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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info->_net = net;
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}
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#else
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static inline struct net *genl_info_net(struct genl_info *info)
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{
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return &init_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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}
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#endif
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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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* @flags: flags
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* @policy: attribute validation policy
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* @doit: standard command callback
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* @dumpit: callback for dumpers
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* @done: completion callback for dumps
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* @ops_list: operations list
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*/
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struct genl_ops
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{
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u8 cmd;
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unsigned int flags;
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const struct nla_policy *policy;
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int (*doit)(struct sk_buff *skb,
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struct genl_info *info);
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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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struct list_head ops_list;
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};
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extern int genl_register_family(struct genl_family *family);
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extern int genl_register_family_with_ops(struct genl_family *family,
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struct genl_ops *ops, size_t n_ops);
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extern int genl_unregister_family(struct genl_family *family);
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extern int genl_register_ops(struct genl_family *, struct genl_ops *ops);
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extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops);
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extern int genl_register_mc_group(struct genl_family *family,
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struct genl_multicast_group *grp);
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extern void genl_unregister_mc_group(struct genl_family *family,
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struct genl_multicast_group *grp);
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/**
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* genlmsg_put - Add generic netlink header to netlink message
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* @skb: socket buffer holding the message
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* @pid: netlink pid the message is addressed to
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* @seq: sequence number (usually the one of the sender)
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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(struct sk_buff *skb, u32 pid, u32 seq,
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struct genl_family *family, int flags, u8 cmd)
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{
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struct nlmsghdr *nlh;
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struct genlmsghdr *hdr;
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nlh = nlmsg_put(skb, pid, seq, family->id, GENL_HDRLEN +
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family->hdrsize, flags);
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if (nlh == NULL)
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return NULL;
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hdr = nlmsg_data(nlh);
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hdr->cmd = cmd;
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hdr->version = family->version;
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hdr->reserved = 0;
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return (char *) hdr + GENL_HDRLEN;
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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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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_pid, 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 int genlmsg_end(struct sk_buff *skb, void *hdr)
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{
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return 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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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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* @net: the net namespace
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* @skb: netlink message as socket buffer
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* @pid: own netlink pid to avoid sending to yourself
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* @group: multicast group id
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* @flags: allocation flags
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*/
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static inline int genlmsg_multicast_netns(struct net *net, struct sk_buff *skb,
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u32 pid, unsigned int group, gfp_t flags)
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{
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return nlmsg_multicast(net->genl_sock, skb, pid, 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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* @skb: netlink message as socket buffer
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* @pid: own netlink pid to avoid sending to yourself
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* @group: multicast group id
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* @flags: allocation flags
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*/
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static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid,
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unsigned int group, gfp_t flags)
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{
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return genlmsg_multicast_netns(&init_net, skb, pid, 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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* @skb: netlink message as socket buffer
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* @pid: own netlink pid to avoid sending to yourself
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* @group: multicast group id
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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(struct sk_buff *skb, u32 pid,
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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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* @pid: netlink pid 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 pid)
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{
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return nlmsg_unicast(net->genl_sock, skb, pid);
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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_pid);
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}
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/**
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* gennlmsg_data - head of message payload
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* @gnlh: genetlink messsage 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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#endif /* __NET_GENERIC_NETLINK_H */
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