LXR linux-bk/include/net/snmp.h

   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 */
  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/* SCTP */
 104#define SCTP_MIB_MAX    __SCTP_MIB_MAX
 105struct sctp_mib {
 106        unsigned long   mibs[SCTP_MIB_MAX];
 107} __SNMP_MIB_ALIGN__;
 108
 109/* Linux */
 110#define LINUX_MIB_MAX   __LINUX_MIB_MAX
 111struct 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], smp_processor_id())->mibs[field]++)
 132#define SNMP_INC_STATS_OFFSET_BH(mib, field, offset)    \
 133        (per_cpu_ptr(mib[0], smp_processor_id())->mibs[field + (offset)]++)
 134#define SNMP_INC_STATS_USER(mib, field) \
 135        (per_cpu_ptr(mib[1], smp_processor_id())->mibs[field]++)
 136#define SNMP_INC_STATS(mib, field)      \
 137        (per_cpu_ptr(mib[!in_softirq()], smp_processor_id())->mibs[field]++)
 138#define SNMP_DEC_STATS(mib, field)      \
 139        (per_cpu_ptr(mib[!in_softirq()], smp_processor_id())->mibs[field]--)
 140#define SNMP_ADD_STATS_BH(mib, field, addend)   \
 141        (per_cpu_ptr(mib[0], smp_processor_id())->mibs[field] += addend)
 142#define SNMP_ADD_STATS_USER(mib, field, addend)         \
 143        (per_cpu_ptr(mib[1], smp_processor_id())->mibs[field] += addend)
 144
 145#endif
 146