memory.c

snmp的源代码,已经在我的ubuntu下编译通过

#include <net-snmp/net-snmp-config.h>

#if HAVE_STDLIB_H
#include <stdlib.h>
#endif
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <ctype.h>
#include <signal.h>
#if HAVE_MACHINE_PARAM_H
#include <machine/param.h>
#endif
#if HAVE_SYS_VMMETER_H
#if !defined(bsdi2) && !defined(netbsd1)
#include <sys/vmmeter.h>
#endif
#endif
#if HAVE_SYS_CONF_H
#include <sys/conf.h>
#endif
#if HAVE_ASM_PAGE_H
#include <asm/page.h>
#endif
#if HAVE_SYS_SWAP_H
#include <sys/swap.h>
#endif
#if HAVE_SYS_FS_H
#include <sys/fs.h>
#else
#if HAVE_UFS_FS_H
#include <ufs/fs.h>
#else
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_SYS_VNODE_H
#include <sys/vnode.h>
#endif
#ifdef HAVE_UFS_UFS_QUOTA_H
#include <ufs/ufs/quota.h>
#endif
#ifdef HAVE_UFS_UFS_INODE_H
#include <ufs/ufs/inode.h>
#endif
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#if HAVE_UFS_FFS_FS_H
#include <ufs/ffs/fs.h>
#endif
#endif
#endif
#if HAVE_MTAB_H
#include <mtab.h>
#endif
#include <sys/stat.h>
#include <errno.h>
#if HAVE_FSTAB_H
#include <fstab.h>
#endif
#if HAVE_SYS_STATVFS_H
#include <sys/statvfs.h>
#endif
#if HAVE_SYS_VFS_H
#include <sys/vfs.h>
#endif
#if (!defined(HAVE_STATVFS)) && defined(HAVE_STATFS)
#if HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#if HAVE_SYS_MOUNT_H
#include <sys/mount.h>
#endif
#if HAVE_SYS_SYSCTL_H
#include <sys/sysctl.h>
#endif
#define statvfs statfs
#endif
#if HAVE_VM_SWAP_PAGER_H
#include <vm/swap_pager.h>
#endif
#if HAVE_SYS_FIXPOINT_H
#include <sys/fixpoint.h>
#endif
#if HAVE_MALLOC_H
#include <malloc.h>
#endif
#if HAVE_STRING_H
#include <string.h>
#endif
#if TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# if HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  include <time.h>
# endif
#endif
#if defined(hpux10) || defined(hpux11)
#include <sys/pstat.h>
#endif

#include <net-snmp/net-snmp-includes.h>
#include <net-snmp/agent/net-snmp-agent-includes.h>
#include <net-snmp/agent/auto_nlist.h>

#include "mibdefs.h"
#include "struct.h"
#include "util_funcs.h"
#include "memory.h"

int             minimumswap;
#ifndef linux
static int      pageshift;      /* log base 2 of the pagesize */
#else
static int      log_procerr = 1;
void
getmem(unsigned long *memtotal, unsigned long *memfree, unsigned long *memshared, 
       unsigned long *buffers, unsigned long *cached, unsigned long *swaptotal, 
       unsigned long *swapfree);
#endif

#ifndef bsdi2
#ifdef NSWAPDEV_SYMBOL
int nswapdev=10;            /* taken from <machine/space.h> */
#endif
#ifdef NSWAPFS_SYMBOL
int nswapfs=10;            /* taken from <machine/space.h> */
#endif
#endif      /* !bsdi2 */

#define DEFAULTMINIMUMSWAP 16000        /* kilobytes */

static FindVarMethod var_extensible_mem;

void
init_memory(void)
{
#ifdef linux
    unsigned long memtotal, memfree, memshared, buffers, cached, swaptotal,
        swapfree;
    /*
     * call once, to log errors for missing vars, then turn off logging
     * of those errors.
     */
    getmem(&memtotal, &memfree, &memshared, &buffers, &cached, &swaptotal,
           &swapfree);
    log_procerr = 0;
#else
    int             pagesize;
#ifdef PHYSMEM_SYMBOL
    auto_nlist(PHYSMEM_SYMBOL, 0, 0);
#endif
#ifdef TOTAL_MEMORY_SYMBOL
    auto_nlist(TOTAL_MEMORY_SYMBOL, 0, 0);
#endif
#ifdef MBSTAT_SYMBOL
    auto_nlist(MBSTAT_SYMBOL, 0, 0);
#endif
#ifdef SWDEVT_SYMBOL
    auto_nlist(SWDEVT_SYMBOL, 0, 0);
#endif
#ifdef FSWDEVT_SYMBOL
    auto_nlist(FSWDEVT_SYMBOL, 0, 0);
#endif
#ifdef NSWAPFS_SYMBOL
    auto_nlist(NSWAPFS_SYMBOL, 0, 0);
#endif
#ifdef NSWAPDEV_SYMBOL
    auto_nlist(NSWAPDEV_SYMBOL, 0, 0);
#endif

#ifndef bsdi2
#ifdef NSWAPDEV_SYMBOL
    if (auto_nlist(NSWAPDEV_SYMBOL, (char *) &nswapdev, sizeof(nswapdev))
        == 0)
        return;
#endif
#ifdef NSWAPFS_SYMBOL
    if (auto_nlist(NSWAPFS_SYMBOL, (char *) &nswapfs, sizeof(nswapfs)) ==
        0)
        return;
#endif
#endif /* bsdi2 */
    pagesize = 1 << PGSHIFT;
    pageshift = 0;
    while (pagesize > 1) {
        pageshift++;
        pagesize >>= 1;
    }
    pageshift -= 10;
#endif /* linux */
    {
        struct variable2 extensible_mem_variables[] = {
            {MIBINDEX, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {MIBINDEX}},
            {ERRORNAME, ASN_OCTET_STR, RONLY, var_extensible_mem, 1,
             {ERRORNAME}},
            {MEMTOTALSWAP, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {MEMTOTALSWAP}},
            {MEMAVAILSWAP, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {MEMAVAILSWAP}},
            {MEMTOTALREAL, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {MEMTOTALREAL}},
            {MEMAVAILREAL, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {MEMAVAILREAL}},
            {MEMTOTALSWAPTXT, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {MEMTOTALSWAPTXT}},
            {MEMUSEDSWAPTXT, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {MEMUSEDSWAPTXT}},
            {MEMTOTALREALTXT, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {MEMTOTALREALTXT}},
            {MEMUSEDREALTXT, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {MEMUSEDREALTXT}},
            {MEMTOTALFREE, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {MEMTOTALFREE}},
            {MEMSWAPMINIMUM, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {MEMSWAPMINIMUM}},
            {MEMSHARED, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {MEMSHARED}},
            {MEMBUFFER, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {MEMBUFFER}},
            {MEMCACHED, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {MEMCACHED}},
            {ERRORFLAG, ASN_INTEGER, RONLY, var_extensible_mem, 1,
             {ERRORFLAG}},
            {ERRORMSG, ASN_OCTET_STR, RONLY, var_extensible_mem, 1,
             {ERRORMSG}}
        };

        /*
         * Define the OID pointer to the top of the mib tree that we're
         * registering underneath 
         */
        oid             mem_variables_oid[] = { UCDAVIS_MIB, MEMMIBNUM };

        /*
         * register ourselves with the agent to handle our mib tree 
         */
        REGISTER_MIB("ucd-snmp/memory", extensible_mem_variables,
                     variable2, mem_variables_oid);

        snmpd_register_config_handler("swap", memory_parse_config,
                                      memory_free_config, "min-avail");
    }
}

void
memory_parse_config(const char *token, char *cptr)
{
    minimumswap = atoi(cptr);
}

void
memory_free_config(void)
{
    minimumswap = DEFAULTMINIMUMSWAP;
}

#ifdef linux
#define MEMINFO_FILE "/proc/meminfo"

void
getmem(unsigned long *memtotal, unsigned long *memfree, unsigned long *memshared, 
       unsigned long *buffers, unsigned long *cached, unsigned long *swaptotal, 
       unsigned long *swapfree)
{
    int         statfd;
    static char *buff = NULL;
    static int  bsize = 0;

    if ((statfd = open(MEMINFO_FILE, O_RDONLY, 0)) != -1) {
        char *b;
        if (bsize == 0) {
            bsize = 128;
            buff = malloc(bsize);
        }
        while (read(statfd, buff, bsize) == bsize) {
            bsize += 256;
            buff = realloc(buff, bsize);
            close(statfd);
            statfd = open(MEMINFO_FILE, O_RDONLY, 0);
        }
        close(statfd);
        b = strstr(buff, "MemTotal: ");
        if (b) 
            sscanf(b, "MemTotal: %lu", memtotal);
        else {
            if(log_procerr)
            snmp_log(LOG_ERR, "No MemTotal line in /proc/meminfo\n");
            *memtotal = 0;
        }
        b = strstr(buff, "MemFree: ");
        if (b) 
            sscanf(b, "MemFree: %lu", memfree);
        else {
            if(log_procerr)
            snmp_log(LOG_ERR, "No MemFree line in /proc/meminfo\n");
            *memfree = 0;
        }
        b = strstr(buff, "MemShared: ");
        if (b)
            sscanf(b, "MemShared: %lu", memshared);
        else {
            if(log_procerr)
            {
            if (0 == netsnmp_os_prematch("Linux","2.4"))
            snmp_log(LOG_ERR, "No MemShared line in /proc/meminfo\n");
            }
            *memshared = 0;
        }
        b = strstr(buff, "Buffers: ");
        if (b)
            sscanf(b, "Buffers: %lu", buffers);
        else {
            if(log_procerr)
            snmp_log(LOG_ERR, "No Buffers line in /proc/meminfo\n");
            *buffers = 0;
        }
        b = strstr(buff, "Cached: ");
        if (b)
            sscanf(b, "Cached: %lu", cached);
        else {
            if(log_procerr)
            snmp_log(LOG_ERR, "No Cached line in /proc/meminfo\n");
            *cached = 0;
        }
        b = strstr(buff, "SwapTotal: ");
        if (b)
            sscanf(b, "SwapTotal: %lu", swaptotal);
        else {
            if(log_procerr)
            snmp_log(LOG_ERR, "No SwapTotal line in /proc/meminfo\n");
            *swaptotal = 0;
        }
        b = strstr(buff, "SwapFree: ");
        if (b)
            sscanf(b, "SwapFree: %lu", swapfree);
        else {
            if(log_procerr)
            snmp_log(LOG_ERR, "No SwapFree line in /proc/meminfo\n");
            *swapfree = 0;
        }
    } else {
        snmp_log_perror(MEMINFO_FILE);
    }
}

enum memory_index { memtotal, memfree, memshared, buffers, cached, swaptotal, 
    swapfree
};

unsigned
memory(int iindex)
{
    unsigned long   mem_total[2], mem_free[2], mem_shared[2], mem_buffers[2], 
                    mem_cached[2],  swap_total[2], swap_free[2];

    getmem(mem_total, mem_free, mem_shared, mem_buffers, mem_cached, swap_total,
           swap_free);
    switch (iindex) {