kernel-ark/include/linux/genetlink.h
Neil Horman e9412c3708 genetlink: Build a generic netlink family module alias
Generic netlink searches for -type- formatted aliases when requesting a module to
fulfill a protocol request (i.e. net-pf-16-proto-16-type-<x>, where x is a type
value).  However generic netlink protocols have no well defined type numbers,
they have string names.  Modify genl_ctrl_getfamily to request an alias in the
format net-pf-16-proto-16-family-<x> instead, where x is a generic string, and
add a macro that builds on the previously added MODULE_ALIAS_NET_PF_PROTO_NAME
macro to allow modules to specifify those generic strings.

Note, l2tp previously hacked together an net-pf-16-proto-16-type-l2tp alias
using the MODULE_ALIAS macro, with these updates we can convert that to use the
PROTO_NAME macro.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: James Chapman <jchapman@katalix.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-29 22:33:56 -04:00

119 lines
2.8 KiB
C

#ifndef __LINUX_GENERIC_NETLINK_H
#define __LINUX_GENERIC_NETLINK_H
#include <linux/types.h>
#include <linux/netlink.h>
#define GENL_NAMSIZ 16 /* length of family name */
#define GENL_MIN_ID NLMSG_MIN_TYPE
#define GENL_MAX_ID 1023
struct genlmsghdr {
__u8 cmd;
__u8 version;
__u16 reserved;
};
#define GENL_HDRLEN NLMSG_ALIGN(sizeof(struct genlmsghdr))
#define GENL_ADMIN_PERM 0x01
#define GENL_CMD_CAP_DO 0x02
#define GENL_CMD_CAP_DUMP 0x04
#define GENL_CMD_CAP_HASPOL 0x08
/*
* List of reserved static generic netlink identifiers:
*/
#define GENL_ID_GENERATE 0
#define GENL_ID_CTRL NLMSG_MIN_TYPE
/**************************************************************************
* Controller
**************************************************************************/
enum {
CTRL_CMD_UNSPEC,
CTRL_CMD_NEWFAMILY,
CTRL_CMD_DELFAMILY,
CTRL_CMD_GETFAMILY,
CTRL_CMD_NEWOPS,
CTRL_CMD_DELOPS,
CTRL_CMD_GETOPS,
CTRL_CMD_NEWMCAST_GRP,
CTRL_CMD_DELMCAST_GRP,
CTRL_CMD_GETMCAST_GRP, /* unused */
__CTRL_CMD_MAX,
};
#define CTRL_CMD_MAX (__CTRL_CMD_MAX - 1)
enum {
CTRL_ATTR_UNSPEC,
CTRL_ATTR_FAMILY_ID,
CTRL_ATTR_FAMILY_NAME,
CTRL_ATTR_VERSION,
CTRL_ATTR_HDRSIZE,
CTRL_ATTR_MAXATTR,
CTRL_ATTR_OPS,
CTRL_ATTR_MCAST_GROUPS,
__CTRL_ATTR_MAX,
};
#define CTRL_ATTR_MAX (__CTRL_ATTR_MAX - 1)
enum {
CTRL_ATTR_OP_UNSPEC,
CTRL_ATTR_OP_ID,
CTRL_ATTR_OP_FLAGS,
__CTRL_ATTR_OP_MAX,
};
#define CTRL_ATTR_OP_MAX (__CTRL_ATTR_OP_MAX - 1)
enum {
CTRL_ATTR_MCAST_GRP_UNSPEC,
CTRL_ATTR_MCAST_GRP_NAME,
CTRL_ATTR_MCAST_GRP_ID,
__CTRL_ATTR_MCAST_GRP_MAX,
};
#define CTRL_ATTR_MCAST_GRP_MAX (__CTRL_ATTR_MCAST_GRP_MAX - 1)
#ifdef __KERNEL__
/* All generic netlink requests are serialized by a global lock. */
extern void genl_lock(void);
extern void genl_unlock(void);
#ifdef CONFIG_PROVE_LOCKING
extern int lockdep_genl_is_held(void);
#endif
/**
* rcu_dereference_genl - rcu_dereference with debug checking
* @p: The pointer to read, prior to dereferencing
*
* Do an rcu_dereference(p), but check caller either holds rcu_read_lock()
* or genl mutex. Note : Please prefer genl_dereference() or rcu_dereference()
*/
#define rcu_dereference_genl(p) \
rcu_dereference_check(p, lockdep_genl_is_held())
/**
* genl_dereference - fetch RCU pointer when updates are prevented by genl mutex
* @p: The pointer to read, prior to dereferencing
*
* Return the value of the specified RCU-protected pointer, but omit
* both the smp_read_barrier_depends() and the ACCESS_ONCE(), because
* caller holds genl mutex.
*/
#define genl_dereference(p) \
rcu_dereference_protected(p, lockdep_genl_is_held())
#define MODULE_ALIAS_GENL_FAMILY(family)\
MODULE_ALIAS_NET_PF_PROTO_NAME(PF_NETLINK, NETLINK_GENERIC, "-family-" family)
#endif /* __KERNEL__ */
#endif /* __LINUX_GENERIC_NETLINK_H */