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  */
  18
  19 #ifndef _SNMP_H
  20 #define _SNMP_H
  21
  22 #include <linux/cache.h>
  23 #include <linux/snmp.h>
  24 #include <linux/smp.h>
  25
  26 /*
  27  * Mibs are stored in array of unsigned long.
  28  */
  29 /*
  30  * struct snmp_mib{}
  31  *  - list of entries for particular API (such as /proc/net/snmp)
  32  *  - name of entries.
  33  */
  34 struct snmp_mib {
  35         const char *name;
  36         int entry;
  37 };
  38
  39 #define SNMP_MIB_ITEM(_name,_entry)     {       \
  40         .name = _name,                          \
  41         .entry = _entry,                        \
  42 }
  43
  44 #define SNMP_MIB_SENTINEL {     \
  45         .name = NULL,           \
  46         .entry = 0,             \
  47 }
  48
  49 /*
  50  * We use all unsigned longs. Linux will soon be so reliable that even
  51  * these will rapidly get too small 8-). Seriously consider the IpInReceives
  52  * count on the 20Gb/s + networks people expect in a few years time!
  53  */
  54
  55 /* IPstats */
  56 #define IPSTATS_MIB_MAX __IPSTATS_MIB_MAX
  57 struct ipstats_mib {
  58         unsigned long   mibs[IPSTATS_MIB_MAX];
  59 };
  60
  61 /* ICMP */
  62 #define ICMP_MIB_DUMMY  __ICMP_MIB_MAX
  63 #define ICMP_MIB_MAX    (__ICMP_MIB_MAX + 1)
  64
  65 struct icmp_mib {
  66         unsigned long   mibs[ICMP_MIB_MAX];
  67 };
  68
  69 #define ICMPMSG_MIB_MAX __ICMPMSG_MIB_MAX
  70 struct icmpmsg_mib {
  71         unsigned long   mibs[ICMPMSG_MIB_MAX];
  72 };
  73
  74 /* ICMP6 (IPv6-ICMP) */
  75 #define ICMP6_MIB_MAX   __ICMP6_MIB_MAX
  76 struct icmpv6_mib {
  77         unsigned long   mibs[ICMP6_MIB_MAX];
  78 };
  79
  80 #define ICMP6MSG_MIB_MAX  __ICMP6MSG_MIB_MAX
  81 struct icmpv6msg_mib {
  82         unsigned long   mibs[ICMP6MSG_MIB_MAX];
  83 };
  84
  85
  86 /* TCP */
  87 #define TCP_MIB_MAX     __TCP_MIB_MAX
  88 struct tcp_mib {
  89         unsigned long   mibs[TCP_MIB_MAX];
  90 };
  91
  92 /* UDP */
  93 #define UDP_MIB_MAX     __UDP_MIB_MAX
  94 struct udp_mib {
  95         unsigned long   mibs[UDP_MIB_MAX];
  96 };
  97
  98 /* Linux */
  99 #define LINUX_MIB_MAX   __LINUX_MIB_MAX
 100 struct linux_mib {
 101         unsigned long   mibs[LINUX_MIB_MAX];
 102 };
 103
 104 /* Linux Xfrm */
 105 #define LINUX_MIB_XFRMMAX       __LINUX_MIB_XFRMMAX
 106 struct linux_xfrm_mib {
 107         unsigned long   mibs[LINUX_MIB_XFRMMAX];
 108 };
 109
 110 /*
 111  * FIXME: On x86 and some other CPUs the split into user and softirq parts
 112  * is not needed because addl $1,memory is atomic against interrupts (but
 113  * atomic_inc would be overkill because of the lock cycles). Wants new
 114  * nonlocked_atomic_inc() primitives -AK
 115  */
 116 #define DEFINE_SNMP_STAT(type, name)    \
 117         __typeof__(type) __percpu *name[2]
 118 #define DECLARE_SNMP_STAT(type, name)   \
 119         extern __typeof__(type) __percpu *name[2]
 120
 121 #define SNMP_STAT_BHPTR(name)   (name[0])
 122 #define SNMP_STAT_USRPTR(name)  (name[1])
 123
 124 #define SNMP_INC_STATS_BH(mib, field)   \
 125                         __this_cpu_inc(mib[0]->mibs[field])
 126 #define SNMP_INC_STATS_USER(mib, field) \
 127                         this_cpu_inc(mib[1]->mibs[field])
 128 #define SNMP_INC_STATS(mib, field)      \
 129                         this_cpu_inc(mib[!in_softirq()]->mibs[field])
 130 #define SNMP_DEC_STATS(mib, field)      \
 131                         this_cpu_dec(mib[!in_softirq()]->mibs[field])
 132 #define SNMP_ADD_STATS_BH(mib, field, addend)   \
 133                         __this_cpu_add(mib[0]->mibs[field], addend)
 134 #define SNMP_ADD_STATS_USER(mib, field, addend) \
 135                         this_cpu_add(mib[1]->mibs[field], addend)
 136 #define SNMP_ADD_STATS(mib, field, addend)      \
 137                         this_cpu_add(mib[0]->mibs[field], addend)
 138 /*
 139  * Use "__typeof__(*mib[0]) *ptr" instead of "__typeof__(mib[0]) ptr"
 140  * to make @ptr a non-percpu pointer.
 141  */
 142 #define SNMP_UPD_PO_STATS(mib, basefield, addend)       \
 143         do { \
 144                 __typeof__(*mib[0]) *ptr; \
 145                 preempt_disable(); \
 146                 ptr = this_cpu_ptr((mib)[!in_softirq()]); \
 147                 ptr->mibs[basefield##PKTS]++; \
 148                 ptr->mibs[basefield##OCTETS] += addend;\
 149                 preempt_enable(); \
 150         } while (0)
 151 #define SNMP_UPD_PO_STATS_BH(mib, basefield, addend)    \
 152         do { \
 153                 __typeof__(*mib[0]) *ptr = \
 154                         __this_cpu_ptr((mib)[!in_softirq()]); \
 155                 ptr->mibs[basefield##PKTS]++; \
 156                 ptr->mibs[basefield##OCTETS] += addend;\
 157         } while (0)
 158 #endif