xref: /openbmc/linux/include/net/snmp.h (revision 87c2ce3b)
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 1.19 2001/06/14 13:40:46 davem 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  */
35 struct 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
73 struct 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 
81 struct 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
87 struct icmpv6_mib {
88 	unsigned long	mibs[ICMP6_MIB_MAX];
89 } __SNMP_MIB_ALIGN__;
90 
91 /* TCP */
92 #define TCP_MIB_MAX	__TCP_MIB_MAX
93 struct tcp_mib {
94 	unsigned long	mibs[TCP_MIB_MAX];
95 } __SNMP_MIB_ALIGN__;
96 
97 /* UDP */
98 #define UDP_MIB_MAX	__UDP_MIB_MAX
99 struct udp_mib {
100 	unsigned long	mibs[UDP_MIB_MAX];
101 } __SNMP_MIB_ALIGN__;
102 
103 /* SCTP */
104 #define SCTP_MIB_MAX	__SCTP_MIB_MAX
105 struct sctp_mib {
106 	unsigned long	mibs[SCTP_MIB_MAX];
107 } __SNMP_MIB_ALIGN__;
108 
109 /* Linux */
110 #define LINUX_MIB_MAX	__LINUX_MIB_MAX
111 struct linux_mib {
112 	unsigned long	mibs[LINUX_MIB_MAX];
113 };
114 
115 
116 /*
117  * FIXME: On x86 and some other CPUs the split into user and softirq parts
118  * is not needed because addl $1,memory is atomic against interrupts (but
119  * atomic_inc would be overkill because of the lock cycles). Wants new
120  * nonlocked_atomic_inc() primitives -AK
121  */
122 #define DEFINE_SNMP_STAT(type, name)	\
123 	__typeof__(type) *name[2]
124 #define DECLARE_SNMP_STAT(type, name)	\
125 	extern __typeof__(type) *name[2]
126 
127 #define SNMP_STAT_BHPTR(name)	(name[0])
128 #define SNMP_STAT_USRPTR(name)	(name[1])
129 
130 #define SNMP_INC_STATS_BH(mib, field) 	\
131 	(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field]++)
132 #define SNMP_INC_STATS_OFFSET_BH(mib, field, offset)	\
133 	(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field + (offset)]++)
134 #define SNMP_INC_STATS_USER(mib, field) \
135 	(per_cpu_ptr(mib[1], raw_smp_processor_id())->mibs[field]++)
136 #define SNMP_INC_STATS(mib, field) 	\
137 	(per_cpu_ptr(mib[!in_softirq()], raw_smp_processor_id())->mibs[field]++)
138 #define SNMP_DEC_STATS(mib, field) 	\
139 	(per_cpu_ptr(mib[!in_softirq()], raw_smp_processor_id())->mibs[field]--)
140 #define SNMP_ADD_STATS_BH(mib, field, addend) 	\
141 	(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field] += addend)
142 #define SNMP_ADD_STATS_USER(mib, field, addend) 	\
143 	(per_cpu_ptr(mib[1], raw_smp_processor_id())->mibs[field] += addend)
144 
145 #endif
146