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