/*
*
* SNMP MIB entries for the IP subsystem.
*
* Alan Cox <gw4pts@gw4pts.ampr.org>
*
* We don't chose to implement SNMP in the kernel (this would
* be silly as SNMP is a pain in the backside in places). We do
* however need to collect the MIB statistics and export them
* out of /proc (eventually)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* $Id: snmp.h,v 1.19 2001/06/14 13:40:46 davem Exp $
*
*/
#ifndef _SNMP_H
#define _SNMP_H
#include <linux/cache.h>
#include <linux/snmp.h>
/*
* Mibs are stored in array of unsigned long.
*/
/*
* struct snmp_mib{}
* - list of entries for particular API (such as /proc/net/snmp)
* - name of entries.
*/
struct snmp_mib {
char *name;
int entry;
};
#define SNMP_MIB_ITEM(_name,_entry) { \
.name = _name, \
.entry = _entry, \
}
#define SNMP_MIB_SENTINEL { \
.name = NULL, \
.entry = 0, \
}
/*
* We use all unsigned longs. Linux will soon be so reliable that even
* these will rapidly get too small 8-). Seriously consider the IpInReceives
* count on the 20Gb/s + networks people expect in a few years time!
*/
/*
* The rule for padding:
* Best is power of two because then the right structure can be found by a
* simple shift. The structure should be always cache line aligned.
* gcc needs n=alignto(cachelinesize, popcnt(sizeof(bla_mib))) shift/add
* instructions to emulate multiply in case it is not power-of-two.
* Currently n is always <=3 for all sizes so simple cache line alignment
* is enough.
*
* The best solution would be a global CPU local area , especially on 64
* and 128byte cacheline machine it makes a *lot* of sense -AK
*/
#define __SNMP_MIB_ALIGN__ ____cacheline_aligned
/* IPstats */
#define IPSTATS_MIB_MAX __IPSTATS_MIB_MAX
struct ipstats_mib {
unsigned long mibs[IPSTATS_MIB_MAX];
} __SNMP_MIB_ALIGN__;
/* ICMP */
#define ICMP_MIB_DUMMY __ICMP_MIB_MAX
#define ICMP_MIB_MAX (__ICMP_MIB_MAX + 1)
struct icmp_mib {
unsigned long mibs[ICMP_MIB_MAX];
} __SNMP_MIB_ALIGN__;
/* ICMP6 (IPv6-ICMP) */
#define ICMP6_MIB_MAX __ICMP6_MIB_MAX
struct icmpv6_mib {
unsigned long mibs[ICMP6_MIB_MAX];
} __SNMP_MIB_ALIGN__;
/* TCP */
#define TCP_MIB_MAX __TCP_MIB_MAX
struct tcp_mib {
unsigned long mibs[TCP_MIB_MAX];
} __SNMP_MIB_ALIGN__;
/* UDP */
#define UDP_MIB_MAX __UDP_MIB_MAX
struct udp_mib {
unsigned long mibs[UDP_MIB_MAX];
} __SNMP_MIB_ALIGN__;
/* Linux */
#define LINUX_MIB_MAX __LINUX_MIB_MAX
struct linux_mib {
unsigned long mibs[LINUX_MIB_MAX];
};
/*
* FIXME: On x86 and some other CPUs the split into user and softirq parts
* is not needed because addl $1,memory is atomic against interrupts (but
* atomic_inc would be overkill because of the lock cycles). Wants new
* nonlocked_atomic_inc() primitives -AK
*/
#define DEFINE_SNMP_STAT(type, name) \
__typeof__(type) *name[2]
#define DECLARE_SNMP_STAT(type, name) \
extern __typeof__(type) *name[2]
#define SNMP_STAT_BHPTR(name) (name[0])
#define SNMP_STAT_USRPTR(name) (name[1])
#define SNMP_INC_STATS_BH(mib, field) \
(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field]++)
#define SNMP_INC_STATS_OFFSET_BH(mib, field, offset) \
(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field + (offset)]++)
#define SNMP_INC_STATS_USER(mib, field) \
(per_cpu_ptr(mib[1], raw_smp_processor_id())->mibs[field]++)
#define SNMP_INC_STATS(mib, field) \
(per_cpu_ptr(mib[!in_softirq()], raw_smp_processor_id())->mibs[field]++)
#define SNMP_DEC_STATS(mib, field) \
(per_cpu_ptr(mib[!in_softirq()], raw_smp_processor_id())->mibs[field]--)
#define SNMP_ADD_STATS_BH(mib, field, addend) \
(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field] += addend)
#define SNMP_ADD_STATS_USER(mib, field, addend) \
(per_cpu_ptr(mib[1], raw_smp_processor_id())->mibs[field] += addend)
#endif
