mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 16:29:59 +00:00
![Florian Westphal](/assets/img/avatar_default.png)
Once event support is added this may need to allocate memory while msk lock is held with softirqs disabled. Not using lock_fast also allows to do the allocation with GFP_KERNEL. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
442 lines
13 KiB
C
442 lines
13 KiB
C
/* 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];
|
|
u8 flags;
|
|
};
|
|
|
|
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
|
|
* @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
|
|
* @small_ops: the small-struct operations supported by this family
|
|
* @n_small_ops: number of small-struct operations supported by this family
|
|
*/
|
|
struct genl_family {
|
|
int id; /* private */
|
|
unsigned int hdrsize;
|
|
char name[GENL_NAMSIZ];
|
|
unsigned int version;
|
|
unsigned int maxattr;
|
|
unsigned int mcgrp_offset; /* private */
|
|
u8 netnsok:1;
|
|
u8 parallel_ops:1;
|
|
u8 n_ops;
|
|
u8 n_small_ops;
|
|
u8 n_mcgrps;
|
|
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);
|
|
const struct genl_ops * ops;
|
|
const struct genl_small_ops *small_ops;
|
|
const struct genl_multicast_group *mcgrps;
|
|
struct module *module;
|
|
};
|
|
|
|
/**
|
|
* 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)
|
|
|
|
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_small_ops - generic netlink operations (small version)
|
|
* @cmd: command identifier
|
|
* @internal_flags: flags used by the family
|
|
* @flags: flags
|
|
* @validate: validation flags from enum genl_validate_flags
|
|
* @doit: standard command callback
|
|
* @dumpit: callback for dumpers
|
|
*
|
|
* This is a cut-down version of struct genl_ops for users who don't need
|
|
* most of the ancillary infra and want to save space.
|
|
*/
|
|
struct genl_small_ops {
|
|
int (*doit)(struct sk_buff *skb, struct genl_info *info);
|
|
int (*dumpit)(struct sk_buff *skb, struct netlink_callback *cb);
|
|
u8 cmd;
|
|
u8 internal_flags;
|
|
u8 flags;
|
|
u8 validate;
|
|
};
|
|
|
|
/**
|
|
* struct genl_ops - generic netlink operations
|
|
* @cmd: command identifier
|
|
* @internal_flags: flags used by the family
|
|
* @flags: flags
|
|
* @maxattr: maximum number of attributes supported
|
|
* @policy: netlink policy (takes precedence over family policy)
|
|
* @validate: validation flags from enum genl_validate_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);
|
|
const struct nla_policy *policy;
|
|
unsigned int maxattr;
|
|
u8 cmd;
|
|
u8 internal_flags;
|
|
u8 flags;
|
|
u8 validate;
|
|
};
|
|
|
|
/**
|
|
* struct genl_info - info that is available during dumpit op call
|
|
* @family: generic netlink family - for internal genl code usage
|
|
* @ops: generic netlink ops - for internal genl code usage
|
|
* @attrs: netlink attributes
|
|
*/
|
|
struct genl_dumpit_info {
|
|
const struct genl_family *family;
|
|
struct genl_ops op;
|
|
struct nlattr **attrs;
|
|
};
|
|
|
|
static inline const struct genl_dumpit_info *
|
|
genl_dumpit_info(struct netlink_callback *cb)
|
|
{
|
|
return cb->data;
|
|
}
|
|
|
|
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 */
|