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 unsigned longs for most mibs but u64 for ipstats.
  51  */
  52 #include <linux/u64_stats_sync.h>
  53
  54 /* IPstats */
  55 #define IPSTATS_MIB_MAX __IPSTATS_MIB_MAX
  56 struct ipstats_mib {
  57         /* mibs[] must be first field of struct ipstats_mib */
  58         u64             mibs[IPSTATS_MIB_MAX];
  59         struct u64_stats_sync syncp;
  60 };
  61
  62 /* ICMP */
  63 #define ICMP_MIB_DUMMY  __ICMP_MIB_MAX
  64 #define ICMP_MIB_MAX    (__ICMP_MIB_MAX + 1)
  65
  66 struct icmp_mib {
  67         unsigned long   mibs[ICMP_MIB_MAX];
  68 };
  69
  70 #define ICMPMSG_MIB_MAX __ICMPMSG_MIB_MAX
  71 struct icmpmsg_mib {
  72         unsigned long   mibs[ICMPMSG_MIB_MAX];
  73 };
  74
  75 /* ICMP6 (IPv6-ICMP) */
  76 #define ICMP6_MIB_MAX   __ICMP6_MIB_MAX
  77 struct icmpv6_mib {
  78         unsigned long   mibs[ICMP6_MIB_MAX];
  79 };
  80
  81 #define ICMP6MSG_MIB_MAX  __ICMP6MSG_MIB_MAX
  82 struct icmpv6msg_mib {
  83         unsigned long   mibs[ICMP6MSG_MIB_MAX];
  84 };
  85
  86
  87 /* TCP */
  88 #define TCP_MIB_MAX     __TCP_MIB_MAX
  89 struct tcp_mib {
  90         unsigned long   mibs[TCP_MIB_MAX];
  91 };
  92
  93 /* UDP */
  94 #define UDP_MIB_MAX     __UDP_MIB_MAX
  95 struct udp_mib {
  96         unsigned long   mibs[UDP_MIB_MAX];
  97 };
  98
  99 /* Linux */
 100 #define LINUX_MIB_MAX   __LINUX_MIB_MAX
 101 struct linux_mib {
 102         unsigned long   mibs[LINUX_MIB_MAX];
 103 };
 104
 105 /* Linux Xfrm */
 106 #define LINUX_MIB_XFRMMAX       __LINUX_MIB_XFRMMAX
 107 struct linux_xfrm_mib {
 108         unsigned long   mibs[LINUX_MIB_XFRMMAX];
 109 };
 110
 111 /*
 112  * FIXME: On x86 and some other CPUs the split into user and softirq parts
 113  * is not needed because addl $1,memory is atomic against interrupts (but
 114  * atomic_inc would be overkill because of the lock cycles). Wants new
 115  * nonlocked_atomic_inc() primitives -AK
 116  */
 117 #define DEFINE_SNMP_STAT(type, name)    \
 118         __typeof__(type) __percpu *name[2]
 119 #define DECLARE_SNMP_STAT(type, name)   \
 120         extern __typeof__(type) __percpu *name[2]
 121
 122 #define SNMP_STAT_BHPTR(name)   (name[0])
 123 #define SNMP_STAT_USRPTR(name)  (name[1])
 124
 125 #define SNMP_INC_STATS_BH(mib, field)   \
 126                         __this_cpu_inc(mib[0]->mibs[field])
 127 #define SNMP_INC_STATS_USER(mib, field) \
 128                         this_cpu_inc(mib[1]->mibs[field])
 129 #define SNMP_INC_STATS(mib, field)      \
 130                         this_cpu_inc(mib[!in_softirq()]->mibs[field])
 131 #define SNMP_DEC_STATS(mib, field)      \
 132                         this_cpu_dec(mib[!in_softirq()]->mibs[field])
 133 #define SNMP_ADD_STATS_BH(mib, field, addend)   \
 134                         __this_cpu_add(mib[0]->mibs[field], addend)
 135 #define SNMP_ADD_STATS_USER(mib, field, addend) \
 136                         this_cpu_add(mib[1]->mibs[field], addend)
 137 #define SNMP_ADD_STATS(mib, field, addend)      \
 138                         this_cpu_add(mib[!in_softirq()]->mibs[field], addend)
 139 /*
 140  * Use "__typeof__(*mib[0]) *ptr" instead of "__typeof__(mib[0]) ptr"
 141  * to make @ptr a non-percpu pointer.
 142  */
 143 #define SNMP_UPD_PO_STATS(mib, basefield, addend)       \
 144         do { \
 145                 __typeof__(*mib[0]) *ptr; \
 146                 preempt_disable(); \
 147                 ptr = this_cpu_ptr((mib)[!in_softirq()]); \
 148                 ptr->mibs[basefield##PKTS]++; \
 149                 ptr->mibs[basefield##OCTETS] += addend;\
 150                 preempt_enable(); \
 151         } while (0)
 152 #define SNMP_UPD_PO_STATS_BH(mib, basefield, addend)    \
 153         do { \
 154                 __typeof__(*mib[0]) *ptr = \
 155                         __this_cpu_ptr((mib)[!in_softirq()]); \
 156                 ptr->mibs[basefield##PKTS]++; \
 157                 ptr->mibs[basefield##OCTETS] += addend;\
 158         } while (0)
 159
 160
 161 #if BITS_PER_LONG==32
 162
 163 #define SNMP_ADD_STATS64_BH(mib, field, addend)                         \
 164         do {                                                            \
 165                 __typeof__(*mib[0]) *ptr = __this_cpu_ptr((mib)[0]);    \
 166                 u64_stats_update_begin(&ptr->syncp);                    \
 167                 ptr->mibs[field] += addend;                             \
 168                 u64_stats_update_end(&ptr->syncp);                      \
 169         } while (0)
 170 #define SNMP_ADD_STATS64_USER(mib, field, addend)                       \
 171         do {                                                            \
 172                 __typeof__(*mib[0]) *ptr;                               \
 173                 preempt_disable();                                      \
 174                 ptr = __this_cpu_ptr((mib)[1]);                         \
 175                 u64_stats_update_begin(&ptr->syncp);                    \
 176                 ptr->mibs[field] += addend;                             \
 177                 u64_stats_update_end(&ptr->syncp);                      \
 178                 preempt_enable();                                       \
 179         } while (0)
 180 #define SNMP_ADD_STATS64(mib, field, addend)                            \
 181         do {                                                            \
 182                 __typeof__(*mib[0]) *ptr;                               \
 183                 preempt_disable();                                      \
 184                 ptr = __this_cpu_ptr((mib)[!in_softirq()]);             \
 185                 u64_stats_update_begin(&ptr->syncp);                    \
 186                 ptr->mibs[field] += addend;                             \
 187                 u64_stats_update_end(&ptr->syncp);                      \
 188                 preempt_enable();                                       \
 189         } while (0)
 190 #define SNMP_INC_STATS64_BH(mib, field) SNMP_ADD_STATS64_BH(mib, field, 1)
 191 #define SNMP_INC_STATS64_USER(mib, field) SNMP_ADD_STATS64_USER(mib, field, 1)
 192 #define SNMP_INC_STATS64(mib, field) SNMP_ADD_STATS64(mib, field, 1)
 193 #define SNMP_UPD_PO_STATS64(mib, basefield, addend)                     \
 194         do {                                                            \
 195                 __typeof__(*mib[0]) *ptr;                               \
 196                 preempt_disable();                                      \
 197                 ptr = __this_cpu_ptr((mib)[!in_softirq()]);             \
 198                 u64_stats_update_begin(&ptr->syncp);                    \
 199                 ptr->mibs[basefield##PKTS]++;                           \
 200                 ptr->mibs[basefield##OCTETS] += addend;                 \
 201                 u64_stats_update_end(&ptr->syncp);                      \
 202                 preempt_enable();                                       \
 203         } while (0)
 204 #define SNMP_UPD_PO_STATS64_BH(mib, basefield, addend)                  \
 205         do {                                                            \
 206                 __typeof__(*mib[0]) *ptr;                               \
 207                 ptr = __this_cpu_ptr((mib)[!in_softirq()]);             \
 208                 u64_stats_update_begin(&ptr->syncp);                    \
 209                 ptr->mibs[basefield##PKTS]++;                           \
 210                 ptr->mibs[basefield##OCTETS] += addend;                 \
 211                 u64_stats_update_end(&ptr->syncp);                      \
 212         } while (0)
 213 #else
 214 #define SNMP_INC_STATS64_BH(mib, field)         SNMP_INC_STATS_BH(mib, field)
 215 #define SNMP_INC_STATS64_USER(mib, field)       SNMP_INC_STATS_USER(mib, field)
 216 #define SNMP_INC_STATS64(mib, field)            SNMP_INC_STATS(mib, field)
 217 #define SNMP_DEC_STATS64(mib, field)            SNMP_DEC_STATS(mib, field)
 218 #define SNMP_ADD_STATS64_BH(mib, field, addend) SNMP_ADD_STATS_BH(mib, field, addend)
 219 #define SNMP_ADD_STATS64_USER(mib, field, addend) SNMP_ADD_STATS_USER(mib, field, addend)
 220 #define SNMP_ADD_STATS64(mib, field, addend)    SNMP_ADD_STATS(mib, field, addend)
 221 #define SNMP_UPD_PO_STATS64(mib, basefield, addend) SNMP_UPD_PO_STATS(mib, basefield, addend)
 222 #define SNMP_UPD_PO_STATS64_BH(mib, basefield, addend) SNMP_UPD_PO_STATS_BH(mib, basefield, addend)
 223 #endif
 224
 225 #endif