linux-stable/include/linux/netfilter/nfnetlink.h
Eric Dumazet 6b75e3e8d6 netfilter: nfnetlink: add RCU in nfnetlink_rcv_msg()
Goal of this patch is to permit nfnetlink providers not mandate
nfnl_mutex being held while nfnetlink_rcv_msg() calls them.

If struct nfnl_callback contains a non NULL call_rcu(), then
nfnetlink_rcv_msg() will use it instead of call() field, holding
rcu_read_lock instead of nfnl_mutex

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Florian Westphal <fw@strlen.de>
CC: Eric Leblond <eric@regit.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-07-18 16:08:07 +02:00

93 lines
2.9 KiB
C

#ifndef _NFNETLINK_H
#define _NFNETLINK_H
#include <linux/types.h>
#include <linux/netfilter/nfnetlink_compat.h>
enum nfnetlink_groups {
NFNLGRP_NONE,
#define NFNLGRP_NONE NFNLGRP_NONE
NFNLGRP_CONNTRACK_NEW,
#define NFNLGRP_CONNTRACK_NEW NFNLGRP_CONNTRACK_NEW
NFNLGRP_CONNTRACK_UPDATE,
#define NFNLGRP_CONNTRACK_UPDATE NFNLGRP_CONNTRACK_UPDATE
NFNLGRP_CONNTRACK_DESTROY,
#define NFNLGRP_CONNTRACK_DESTROY NFNLGRP_CONNTRACK_DESTROY
NFNLGRP_CONNTRACK_EXP_NEW,
#define NFNLGRP_CONNTRACK_EXP_NEW NFNLGRP_CONNTRACK_EXP_NEW
NFNLGRP_CONNTRACK_EXP_UPDATE,
#define NFNLGRP_CONNTRACK_EXP_UPDATE NFNLGRP_CONNTRACK_EXP_UPDATE
NFNLGRP_CONNTRACK_EXP_DESTROY,
#define NFNLGRP_CONNTRACK_EXP_DESTROY NFNLGRP_CONNTRACK_EXP_DESTROY
__NFNLGRP_MAX,
};
#define NFNLGRP_MAX (__NFNLGRP_MAX - 1)
/* General form of address family dependent message.
*/
struct nfgenmsg {
__u8 nfgen_family; /* AF_xxx */
__u8 version; /* nfnetlink version */
__be16 res_id; /* resource id */
};
#define NFNETLINK_V0 0
/* netfilter netlink message types are split in two pieces:
* 8 bit subsystem, 8bit operation.
*/
#define NFNL_SUBSYS_ID(x) ((x & 0xff00) >> 8)
#define NFNL_MSG_TYPE(x) (x & 0x00ff)
/* No enum here, otherwise __stringify() trick of MODULE_ALIAS_NFNL_SUBSYS()
* won't work anymore */
#define NFNL_SUBSYS_NONE 0
#define NFNL_SUBSYS_CTNETLINK 1
#define NFNL_SUBSYS_CTNETLINK_EXP 2
#define NFNL_SUBSYS_QUEUE 3
#define NFNL_SUBSYS_ULOG 4
#define NFNL_SUBSYS_OSF 5
#define NFNL_SUBSYS_IPSET 6
#define NFNL_SUBSYS_COUNT 7
#ifdef __KERNEL__
#include <linux/netlink.h>
#include <linux/capability.h>
#include <net/netlink.h>
struct nfnl_callback {
int (*call)(struct sock *nl, struct sk_buff *skb,
const struct nlmsghdr *nlh,
const struct nlattr * const cda[]);
int (*call_rcu)(struct sock *nl, struct sk_buff *skb,
const struct nlmsghdr *nlh,
const struct nlattr * const cda[]);
const struct nla_policy *policy; /* netlink attribute policy */
const u_int16_t attr_count; /* number of nlattr's */
};
struct nfnetlink_subsystem {
const char *name;
__u8 subsys_id; /* nfnetlink subsystem ID */
__u8 cb_count; /* number of callbacks */
const struct nfnl_callback *cb; /* callback for individual types */
};
extern int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n);
extern int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n);
extern int nfnetlink_has_listeners(struct net *net, unsigned int group);
extern int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, unsigned group,
int echo, gfp_t flags);
extern int nfnetlink_set_err(struct net *net, u32 pid, u32 group, int error);
extern int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u_int32_t pid, int flags);
extern void nfnl_lock(void);
extern void nfnl_unlock(void);
#define MODULE_ALIAS_NFNL_SUBSYS(subsys) \
MODULE_ALIAS("nfnetlink-subsys-" __stringify(subsys))
#endif /* __KERNEL__ */
#endif /* _NFNETLINK_H */