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 #include <linux/smp.h>
  27
  28 /*
  29  * Mibs are stored in array of unsigned long.
  30  */
  31 /*
  32  * struct snmp_mib{}
  33  *  - list of entries for particular API (such as /proc/net/snmp)
  34  *  - name of entries.
  35  */
  36 struct snmp_mib {
  37         char *name;
  38         int entry;
  39 };
  40
  41 #define SNMP_MIB_ITEM(_name,_entry)     {       \
  42         .name = _name,                          \
  43         .entry = _entry,                        \
  44 }
  45
  46 #define SNMP_MIB_SENTINEL {     \
  47         .name = NULL,           \
  48         .entry = 0,             \
  49 }
  50
  51 /*
  52  * We use all unsigned longs. Linux will soon be so reliable that even
  53  * these will rapidly get too small 8-). Seriously consider the IpInReceives
  54  * count on the 20Gb/s + networks people expect in a few years time!
  55  */
  56
  57 /*
  58  * The rule for padding:
  59  * Best is power of two because then the right structure can be found by a
  60  * simple shift. The structure should be always cache line aligned.
  61  * gcc needs n=alignto(cachelinesize, popcnt(sizeof(bla_mib))) shift/add
  62  * instructions to emulate multiply in case it is not power-of-two.
  63  * Currently n is always <=3 for all sizes so simple cache line alignment
  64  * is enough.
  65  *
  66  * The best solution would be a global CPU local area , especially on 64
  67  * and 128byte cacheline machine it makes a *lot* of sense -AK
  68  */
  69
  70 #define __SNMP_MIB_ALIGN__      ____cacheline_aligned
  71
  72 /* IPstats */
  73 #define IPSTATS_MIB_MAX __IPSTATS_MIB_MAX
  74 struct ipstats_mib {
  75         unsigned long   mibs[IPSTATS_MIB_MAX];
  76 } __SNMP_MIB_ALIGN__;
  77
  78 /* ICMP */
  79 #define ICMP_MIB_DUMMY  __ICMP_MIB_MAX
  80 #define ICMP_MIB_MAX    (__ICMP_MIB_MAX + 1)
  81
  82 struct icmp_mib {
  83         unsigned long   mibs[ICMP_MIB_MAX];
  84 } __SNMP_MIB_ALIGN__;
  85
  86 #define ICMPMSG_MIB_MAX __ICMPMSG_MIB_MAX
  87 struct icmpmsg_mib {
  88         unsigned long   mibs[ICMPMSG_MIB_MAX];
  89 } __SNMP_MIB_ALIGN__;
  90
  91 /* ICMP6 (IPv6-ICMP) */
  92 #define ICMP6_MIB_MAX   __ICMP6_MIB_MAX
  93 struct icmpv6_mib {
  94         unsigned long   mibs[ICMP6_MIB_MAX];
  95 } __SNMP_MIB_ALIGN__;
  96
  97 #define ICMP6MSG_MIB_MAX  __ICMP6MSG_MIB_MAX
  98 struct icmpv6msg_mib {
  99         unsigned long   mibs[ICMP6MSG_MIB_MAX];
 100 } __SNMP_MIB_ALIGN__;
 101
 102
 103 /* TCP */
 104 #define TCP_MIB_MAX     __TCP_MIB_MAX
 105 struct tcp_mib {
 106         unsigned long   mibs[TCP_MIB_MAX];
 107 } __SNMP_MIB_ALIGN__;
 108
 109 /* UDP */
 110 #define UDP_MIB_MAX     __UDP_MIB_MAX
 111 struct udp_mib {
 112         unsigned long   mibs[UDP_MIB_MAX];
 113 } __SNMP_MIB_ALIGN__;
 114
 115 /* Linux */
 116 #define LINUX_MIB_MAX   __LINUX_MIB_MAX
 117 struct linux_mib {
 118         unsigned long   mibs[LINUX_MIB_MAX];
 119 };
 120
 121 /* Linux Xfrm */
 122 #define LINUX_MIB_XFRMMAX       __LINUX_MIB_XFRMMAX
 123 struct linux_xfrm_mib {
 124         unsigned long   mibs[LINUX_MIB_XFRMMAX];
 125 };
 126
 127 /*
 128  * FIXME: On x86 and some other CPUs the split into user and softirq parts
 129  * is not needed because addl $1,memory is atomic against interrupts (but
 130  * atomic_inc would be overkill because of the lock cycles). Wants new
 131  * nonlocked_atomic_inc() primitives -AK
 132  */
 133 #define DEFINE_SNMP_STAT(type, name)    \
 134         __typeof__(type) *name[2]
 135 #define DECLARE_SNMP_STAT(type, name)   \
 136         extern __typeof__(type) *name[2]
 137
 138 #define SNMP_STAT_BHPTR(name)   (name[0])
 139 #define SNMP_STAT_USRPTR(name)  (name[1])
 140
 141 #define SNMP_INC_STATS_BH(mib, field)   \
 142         (per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field]++)
 143 #define SNMP_INC_STATS_USER(mib, field) \
 144         do { \
 145                 per_cpu_ptr(mib[1], get_cpu())->mibs[field]++; \
 146                 put_cpu(); \
 147         } while (0)
 148 #define SNMP_INC_STATS(mib, field)      \
 149         do { \
 150                 per_cpu_ptr(mib[!in_softirq()], get_cpu())->mibs[field]++; \
 151                 put_cpu(); \
 152         } while (0)
 153 #define SNMP_DEC_STATS(mib, field)      \
 154         do { \
 155                 per_cpu_ptr(mib[!in_softirq()], get_cpu())->mibs[field]--; \
 156                 put_cpu(); \
 157         } while (0)
 158 #define SNMP_ADD_STATS_BH(mib, field, addend)   \
 159         (per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field] += addend)
 160 #define SNMP_ADD_STATS_USER(mib, field, addend)         \
 161         do { \
 162                 per_cpu_ptr(mib[1], get_cpu())->mibs[field] += addend; \
 163                 put_cpu(); \
 164         } while (0)
 165
 166 #endif