1/*
2 *
3 *		SNMP MIB entries for the IP subsystem.
4 *
5 *		Alan Cox <gw4pts@gw4pts.ampr.org>
6 *
7 *		We don't chose to implement SNMP in the kernel (this would
8 *		be silly as SNMP is a pain in the backside in places). We do
9 *		however need to collect the MIB statistics and export them
10 *		out of /proc (eventually)
11 *
12 *		This program is free software; you can redistribute it and/or
13 *		modify it under the terms of the GNU General Public License
14 *		as published by the Free Software Foundation; either version
15 *		2 of the License, or (at your option) any later version.
16 *
17 *		$Id: snmp.h,v 1.1.1.1 2007/08/03 18:53:45 Exp $
18 *
19 */
20
21#ifndef _SNMP_H
22#define _SNMP_H
23
24#include <linux/cache.h>
25#include <linux/snmp.h>
26
27/*
28 * Mibs are stored in array of unsigned long.
29 */
30/*
31 * struct snmp_mib{}
32 *  - list of entries for particular API (such as /proc/net/snmp)
33 *  - name of entries.
34 */
35struct snmp_mib {
36	char *name;
37	int entry;
38};
39
40#define SNMP_MIB_ITEM(_name,_entry)	{	\
41	.name = _name,				\
42	.entry = _entry,			\
43}
44
45#define SNMP_MIB_SENTINEL {	\
46	.name = NULL,		\
47	.entry = 0,		\
48}
49
50/*
51 * We use all unsigned longs. Linux will soon be so reliable that even
52 * these will rapidly get too small 8-). Seriously consider the IpInReceives
53 * count on the 20Gb/s + networks people expect in a few years time!
54 */
55
56/*
57 * The rule for padding:
58 * Best is power of two because then the right structure can be found by a
59 * simple shift. The structure should be always cache line aligned.
60 * gcc needs n=alignto(cachelinesize, popcnt(sizeof(bla_mib))) shift/add
61 * instructions to emulate multiply in case it is not power-of-two.
62 * Currently n is always <=3 for all sizes so simple cache line alignment
63 * is enough.
64 *
65 * The best solution would be a global CPU local area , especially on 64
66 * and 128byte cacheline machine it makes a *lot* of sense -AK
67 */
68
69#define __SNMP_MIB_ALIGN__	____cacheline_aligned
70
71/* IPstats */
72#define IPSTATS_MIB_MAX	__IPSTATS_MIB_MAX
73struct ipstats_mib {
74	unsigned long	mibs[IPSTATS_MIB_MAX];
75} __SNMP_MIB_ALIGN__;
76
77/* ICMP */
78#define ICMP_MIB_DUMMY	__ICMP_MIB_MAX
79#define ICMP_MIB_MAX	(__ICMP_MIB_MAX + 1)
80
81struct icmp_mib {
82	unsigned long	mibs[ICMP_MIB_MAX];
83} __SNMP_MIB_ALIGN__;
84
85/* ICMP6 (IPv6-ICMP) */
86#define ICMP6_MIB_MAX	__ICMP6_MIB_MAX
87struct icmpv6_mib {
88	unsigned long	mibs[ICMP6_MIB_MAX];
89} __SNMP_MIB_ALIGN__;
90
91/* TCP */
92#define TCP_MIB_MAX	__TCP_MIB_MAX
93struct tcp_mib {
94	unsigned long	mibs[TCP_MIB_MAX];
95} __SNMP_MIB_ALIGN__;
96
97/* UDP */
98#define UDP_MIB_MAX	__UDP_MIB_MAX
99struct udp_mib {
100	unsigned long	mibs[UDP_MIB_MAX];
101} __SNMP_MIB_ALIGN__;
102
103/* Linux */
104#define LINUX_MIB_MAX	__LINUX_MIB_MAX
105struct linux_mib {
106	unsigned long	mibs[LINUX_MIB_MAX];
107};
108
109
110#define DEFINE_SNMP_STAT(type, name)	\
111	__typeof__(type) *name[2]
112#define DECLARE_SNMP_STAT(type, name)	\
113	extern __typeof__(type) *name[2]
114
115#define SNMP_STAT_BHPTR(name)	(name[0])
116#define SNMP_STAT_USRPTR(name)	(name[1])
117
118#define SNMP_INC_STATS_BH(mib, field) 	\
119	(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field]++)
120#define SNMP_INC_STATS_OFFSET_BH(mib, field, offset)	\
121	(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field + (offset)]++)
122#define SNMP_INC_STATS_USER(mib, field) \
123	(per_cpu_ptr(mib[1], raw_smp_processor_id())->mibs[field]++)
124#define SNMP_INC_STATS(mib, field) 	\
125	(per_cpu_ptr(mib[!in_softirq()], raw_smp_processor_id())->mibs[field]++)
126#define SNMP_DEC_STATS(mib, field) 	\
127	(per_cpu_ptr(mib[!in_softirq()], raw_smp_processor_id())->mibs[field]--)
128#define SNMP_ADD_STATS_BH(mib, field, addend) 	\
129	(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field] += addend)
130#define SNMP_ADD_STATS_USER(mib, field, addend) 	\
131	(per_cpu_ptr(mib[1], raw_smp_processor_id())->mibs[field] += addend)
132
133#endif
134