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 /* per network ns counters */
  76 struct icmpv6_mib {
  77         unsigned long   mibs[ICMP6_MIB_MAX];
  78 };
  79 /* per device counters, (shared on all cpus) */
  80 struct icmpv6_mib_device {
  81         atomic_long_t   mibs[ICMP6_MIB_MAX];
  82 };
  83
  84 #define ICMP6MSG_MIB_MAX  __ICMP6MSG_MIB_MAX
  85 /* per network ns counters */
  86 struct icmpv6msg_mib {
  87         unsigned long   mibs[ICMP6MSG_MIB_MAX];
  88 };
  89 /* per device counters, (shared on all cpus) */
  90 struct icmpv6msg_mib_device {
  91         atomic_long_t   mibs[ICMP6MSG_MIB_MAX];
  92 };
  93
  94
  95 /* TCP */
  96 #define TCP_MIB_MAX     __TCP_MIB_MAX
  97 struct tcp_mib {
  98         unsigned long   mibs[TCP_MIB_MAX];
  99 };
 100
 101 /* UDP */
 102 #define UDP_MIB_MAX     __UDP_MIB_MAX
 103 struct udp_mib {
 104         unsigned long   mibs[UDP_MIB_MAX];
 105 };
 106
 107 /* Linux */
 108 #define LINUX_MIB_MAX   __LINUX_MIB_MAX
 109 struct linux_mib {
 110         unsigned long   mibs[LINUX_MIB_MAX];
 111 };
 112
 113 /* Linux Xfrm */
 114 #define LINUX_MIB_XFRMMAX       __LINUX_MIB_XFRMMAX
 115 struct linux_xfrm_mib {
 116         unsigned long   mibs[LINUX_MIB_XFRMMAX];
 117 };
 118
 119 /*
 120  * FIXME: On x86 and some other CPUs the split into user and softirq parts
 121  * is not needed because addl $1,memory is atomic against interrupts (but
 122  * atomic_inc would be overkill because of the lock cycles). Wants new
 123  * nonlocked_atomic_inc() primitives -AK
 124  */
 125 #define DEFINE_SNMP_STAT(type, name)    \
 126         __typeof__(type) __percpu *name[2]
 127 #define DEFINE_SNMP_STAT_ATOMIC(type, name)     \
 128         __typeof__(type) *name
 129 #define DECLARE_SNMP_STAT(type, name)   \
 130         extern __typeof__(type) __percpu *name[2]
 131
 132 #define SNMP_STAT_BHPTR(name)   (name[0])
 133 #define SNMP_STAT_USRPTR(name)  (name[1])
 134
 135 #define SNMP_INC_STATS_BH(mib, field)   \
 136                         __this_cpu_inc(mib[0]->mibs[field])
 137 #define SNMP_INC_STATS_USER(mib, field) \
 138                         this_cpu_inc(mib[1]->mibs[field])
 139 #define SNMP_INC_STATS_ATOMIC_LONG(mib, field)  \
 140                         atomic_long_inc(&mib->mibs[field])
 141 #define SNMP_INC_STATS(mib, field)      \
 142                         this_cpu_inc(mib[!in_softirq()]->mibs[field])
 143 #define SNMP_DEC_STATS(mib, field)      \
 144                         this_cpu_dec(mib[!in_softirq()]->mibs[field])
 145 #define SNMP_ADD_STATS_BH(mib, field, addend)   \
 146                         __this_cpu_add(mib[0]->mibs[field], addend)
 147 #define SNMP_ADD_STATS_USER(mib, field, addend) \
 148                         this_cpu_add(mib[1]->mibs[field], addend)
 149 #define SNMP_ADD_STATS(mib, field, addend)      \
 150                         this_cpu_add(mib[!in_softirq()]->mibs[field], addend)
 151 /*
 152  * Use "__typeof__(*mib[0]) *ptr" instead of "__typeof__(mib[0]) ptr"
 153  * to make @ptr a non-percpu pointer.
 154  */
 155 #define SNMP_UPD_PO_STATS(mib, basefield, addend)       \
 156         do { \
 157                 __typeof__(*mib[0]) *ptr; \
 158                 preempt_disable(); \
 159                 ptr = this_cpu_ptr((mib)[!in_softirq()]); \
 160                 ptr->mibs[basefield##PKTS]++; \
 161                 ptr->mibs[basefield##OCTETS] += addend;\
 162                 preempt_enable(); \
 163         } while (0)
 164 #define SNMP_UPD_PO_STATS_BH(mib, basefield, addend)    \
 165         do { \
 166                 __typeof__(*mib[0]) *ptr = \
 167                         __this_cpu_ptr((mib)[0]); \
 168                 ptr->mibs[basefield##PKTS]++; \
 169                 ptr->mibs[basefield##OCTETS] += addend;\
 170         } while (0)
 171
 172
 173 #if BITS_PER_LONG==32
 174
 175 #define SNMP_ADD_STATS64_BH(mib, field, addend)                         \
 176         do {                                                            \
 177                 __typeof__(*mib[0]) *ptr = __this_cpu_ptr((mib)[0]);    \
 178                 u64_stats_update_begin(&ptr->syncp);                    \
 179                 ptr->mibs[field] += addend;                             \
 180                 u64_stats_update_end(&ptr->syncp);                      \
 181         } while (0)
 182 #define SNMP_ADD_STATS64_USER(mib, field, addend)                       \
 183         do {                                                            \
 184                 __typeof__(*mib[0]) *ptr;                               \
 185                 preempt_disable();                                      \
 186                 ptr = __this_cpu_ptr((mib)[1]);                         \
 187                 u64_stats_update_begin(&ptr->syncp);                    \
 188                 ptr->mibs[field] += addend;                             \
 189                 u64_stats_update_end(&ptr->syncp);                      \
 190                 preempt_enable();                                       \
 191         } while (0)
 192 #define SNMP_ADD_STATS64(mib, field, addend)                            \
 193         do {                                                            \
 194                 __typeof__(*mib[0]) *ptr;                               \
 195                 preempt_disable();                                      \
 196                 ptr = __this_cpu_ptr((mib)[!in_softirq()]);             \
 197                 u64_stats_update_begin(&ptr->syncp);                    \
 198                 ptr->mibs[field] += addend;                             \
 199                 u64_stats_update_end(&ptr->syncp);                      \
 200                 preempt_enable();                                       \
 201         } while (0)
 202 #define SNMP_INC_STATS64_BH(mib, field) SNMP_ADD_STATS64_BH(mib, field, 1)
 203 #define SNMP_INC_STATS64_USER(mib, field) SNMP_ADD_STATS64_USER(mib, field, 1)
 204 #define SNMP_INC_STATS64(mib, field) SNMP_ADD_STATS64(mib, field, 1)
 205 #define SNMP_UPD_PO_STATS64(mib, basefield, addend)                     \
 206         do {                                                            \
 207                 __typeof__(*mib[0]) *ptr;                               \
 208                 preempt_disable();                                      \
 209                 ptr = __this_cpu_ptr((mib)[!in_softirq()]);             \
 210                 u64_stats_update_begin(&ptr->syncp);                    \
 211                 ptr->mibs[basefield##PKTS]++;                           \
 212                 ptr->mibs[basefield##OCTETS] += addend;                 \
 213                 u64_stats_update_end(&ptr->syncp);                      \
 214                 preempt_enable();                                       \
 215         } while (0)
 216 #define SNMP_UPD_PO_STATS64_BH(mib, basefield, addend)                  \
 217         do {                                                            \
 218                 __typeof__(*mib[0]) *ptr;                               \
 219                 ptr = __this_cpu_ptr((mib)[0]);                         \
 220                 u64_stats_update_begin(&ptr->syncp);                    \
 221                 ptr->mibs[basefield##PKTS]++;                           \
 222                 ptr->mibs[basefield##OCTETS] += addend;                 \
 223                 u64_stats_update_end(&ptr->syncp);                      \
 224         } while (0)
 225 #else
 226 #define SNMP_INC_STATS64_BH(mib, field)         SNMP_INC_STATS_BH(mib, field)
 227 #define SNMP_INC_STATS64_USER(mib, field)       SNMP_INC_STATS_USER(mib, field)
 228 #define SNMP_INC_STATS64(mib, field)            SNMP_INC_STATS(mib, field)
 229 #define SNMP_DEC_STATS64(mib, field)            SNMP_DEC_STATS(mib, field)
 230 #define SNMP_ADD_STATS64_BH(mib, field, addend) SNMP_ADD_STATS_BH(mib, field, addend)
 231 #define SNMP_ADD_STATS64_USER(mib, field, addend) SNMP_ADD_STATS_USER(mib, field, addend)
 232 #define SNMP_ADD_STATS64(mib, field, addend)    SNMP_ADD_STATS(mib, field, addend)
 233 #define SNMP_UPD_PO_STATS64(mib, basefield, addend) SNMP_UPD_PO_STATS(mib, basefield, addend)
 234 #define SNMP_UPD_PO_STATS64_BH(mib, basefield, addend) SNMP_UPD_PO_STATS_BH(mib, basefield, addend)
 235 #endif
 236
 237 #endif