vmstat_linux.c

开发snmp的开发包有两个开放的SNMP开发库

	    sscanf(b, "pgpgin %u", pin);
	else {
	    if (first)
		snmp_log(LOG_ERR, "No pgpgin line in %s\n", VMSTAT_FILE);
	    *pin = 0;
	}
	b = strstr(vmbuff, "pgpgout ");
	if (b)
	    sscanf(b, "pgpgout %u", pout);
	else {
	    if (first)
		snmp_log(LOG_ERR, "No pgpgout line in %s\n", VMSTAT_FILE);
	    *pout = 0;
	}
	b = strstr(vmbuff, "pswpin ");
	if (b)
	    sscanf(b, "pswpin %u", swpin);
	else {
	    if (first)
		snmp_log(LOG_ERR, "No pswpin line in %s\n", VMSTAT_FILE);
	    *swpin = 0;
	}
	b = strstr(vmbuff, "pswpout ");
	if (b)
	    sscanf(b, "pswpout %u", swpout);
	else {
	    if (first)
		snmp_log(LOG_ERR, "No pswpout line in %s\n", VMSTAT_FILE);
	    *swpout = 0;
	}
    }
    else {
	b = strstr(buff, "page ");
	if (b)
	    sscanf(b, "page %u %u", pin, pout);
	else {
	    if (first)
		snmp_log(LOG_ERR, "No page line in %s\n", STAT_FILE);
	    *pin = *pout = 0;
	}
	b = strstr(buff, "swap ");
	if (b)
	    sscanf(b, "swap %u %u", swpin, swpout);
	else {
	    if (first)
		snmp_log(LOG_ERR, "No swap line in %s\n", STAT_FILE);
	    *swpin = *swpout = 0;
	}
    }
    b = strstr(buff, "intr ");
    if (b) {
	sscanf(b, "intr %llu %llu", &itotll, &i1ll);
        *itot = (unsigned)itotll;
        *i1 = (unsigned)i1ll;
    }
    else {
	if (first)
	    snmp_log(LOG_ERR, "No intr line in %s\n", STAT_FILE);
	*itot = 0;
    }
    b = strstr(buff, "ctxt ");
    if (b) {
	sscanf(b, "ctxt %llu", &ctll);
        *ct = (unsigned long)ctll;
    }
    else {
	if (first)
	    snmp_log(LOG_ERR, "No ctxt line in %s\n", STAT_FILE);
	*ct = 0;
    }
    first = 0;
}

enum vmstat_index { swapin = 0, swapout,
    rawswapin, rawswapout,
    iosent, ioreceive,
    rawiosent, rawioreceive,
    sysinterrupts, syscontext,
    cpuuser, cpusystem, cpuidle,
    cpurawuser, cpurawnice,
    cpurawsystem, cpurawidle,
    cpurawinter, cpurawsoft, cpurawwait,
    rawinterrupts, rawcontext
};

static unsigned
vmstat(int iindex)
{
    double          duse, dsys, didl, ddiv, divo2;
    double          druse, drnic, drsys, dridl;
    unsigned int    hertz;
    double          ddiv2;

    netsnmp_cpu_info *cpu;
    netsnmp_cpu_load();
    cpu = netsnmp_cpu_get_byIdx( -1, 0 );

    duse = cpu->user_ticks + cpu->nice_ticks;
    dsys = cpu->sys_ticks;
    didl = cpu->idle_ticks;
    ddiv = duse + dsys + didl;
    hertz = sysconf(_SC_CLK_TCK);  /* get ticks/s from system */
    divo2 = ddiv / 2;
    druse = cpu->user_ticks;
    drnic = cpu->nice_ticks;
    drsys = cpu->sys_ticks;
    dridl = cpu->idle_ticks;

    ddiv2 = ddiv + cpu->wait_ticks
                 + cpu->intrpt_ticks
                 + cpu->sirq_ticks;
    if (cpu->history) {
        duse  -= (cpu->history[0].user_hist + cpu->history[0].nice_hist);
        dsys  -=  cpu->history[0].sys_hist;
        didl  -=  cpu->history[0].idle_hist;
        ddiv2 -=  cpu->history[0].total_hist;
    }
    if (!ddiv) ddiv=1;   /* Protect against division-by-0 */
 
    switch (iindex) {
    case swapin:
        return (cpu->swapIn  * 4 * hertz + divo2) / ddiv;
    case swapout:
        return (cpu->swapOut * 4 * hertz + divo2) / ddiv;
    case iosent:
        return (cpu->pageIn      * hertz + divo2) / ddiv;
    case ioreceive:
        return (cpu->pageOut     * hertz + divo2) / ddiv;
    case sysinterrupts:
        return (cpu->nInterrupts  * hertz + divo2) / ddiv;
    case syscontext:
        return (cpu->nCtxSwitches * hertz + divo2) / ddiv;
    case cpuuser:
        return (ddiv2 ? 100 * duse / ddiv2 : 0);
    case cpusystem:
        return (ddiv2 ? 100 * dsys / ddiv2 : 0);
    case cpuidle:
        return (ddiv2 ? 100 * didl / ddiv2 : 0);
    case cpurawuser:
        return druse;
    case cpurawnice:
        return drnic;
    case cpurawsystem:
        return drsys;
    case cpurawidle:
        return dridl;
    case rawinterrupts:
        return cpu->nInterrupts;
    case rawcontext:
        return cpu->nCtxSwitches;
    case cpurawwait:
	return cpu->wait_ticks;
    case cpurawinter:
	return cpu->intrpt_ticks;
    case cpurawsoft:
	return cpu->sirq_ticks;
    case rawiosent:
	return cpu->pageOut*2;
    case rawioreceive:
	return cpu->pageIn*2;
    case rawswapin:
	return cpu->swapIn;
    case rawswapout:
	return cpu->swapOut;
    default:
        return -1;
    }
}

unsigned char  *
var_extensible_vmstat(struct variable *vp,
                      oid * name,
                      size_t * length,
                      int exact,
                      size_t * var_len, WriteMethod ** write_method)
{

    static long     long_ret;
    static char     errmsg[300];

    long_ret = 0;               /* set to 0 as default */

    if (header_generic(vp, name, length, exact, var_len, write_method))
        return (NULL);
    switch (vp->magic) {
    case MIBINDEX:
        long_ret = 1;
        return ((u_char *) (&long_ret));
    case ERRORNAME:            /* dummy name */
        sprintf(errmsg, "systemStats");
        *var_len = strlen(errmsg);
        return ((u_char *) (errmsg));
    case SWAPIN:
        long_ret = vmstat(swapin);
        return ((u_char *) (&long_ret));
    case SWAPOUT:
        long_ret = vmstat(swapout);
        return ((u_char *) (&long_ret));
    case RAWSWAPIN:
        long_ret = vmstat(rawswapin);
        return ((u_char *) (&long_ret));
    case RAWSWAPOUT:
        long_ret = vmstat(rawswapout);
        return ((u_char *) (&long_ret));
    case IOSENT:
        long_ret = vmstat(iosent);
        return ((u_char *) (&long_ret));
    case IORECEIVE:
        long_ret = vmstat(ioreceive);
        return ((u_char *) (&long_ret));
    case IORAWSENT:
        long_ret = vmstat(rawiosent);
        return ((u_char *) (&long_ret));
    case IORAWRECEIVE:
        long_ret = vmstat(rawioreceive);
        return ((u_char *) (&long_ret));
    case SYSINTERRUPTS:
        long_ret = vmstat(sysinterrupts);
        return ((u_char *) (&long_ret));
    case SYSCONTEXT:
        long_ret = vmstat(syscontext);
        return ((u_char *) (&long_ret));
    case CPUUSER:
        long_ret = vmstat(cpuuser);
        return ((u_char *) (&long_ret));
    case CPUSYSTEM:
        long_ret = vmstat(cpusystem);
        return ((u_char *) (&long_ret));
    case CPUIDLE:
        long_ret = vmstat(cpuidle);
        return ((u_char *) (&long_ret));
    case CPURAWUSER:
        long_ret = vmstat(cpurawuser);
        return ((u_char *) (&long_ret));
    case CPURAWNICE:
        long_ret = vmstat(cpurawnice);
        return ((u_char *) (&long_ret));
    case CPURAWSYSTEM:
        long_ret = vmstat(cpurawsystem)+vmstat(cpurawinter)+vmstat(cpurawsoft);
        return ((u_char *) (&long_ret));
    case CPURAWKERNEL:
        long_ret = vmstat(cpurawsystem);
        return ((u_char *) (&long_ret));
    case CPURAWIDLE:
        long_ret = vmstat(cpurawidle);
        return ((u_char *) (&long_ret));
    case SYSRAWINTERRUPTS:
	long_ret = vmstat(rawinterrupts);
	return (u_char *)&long_ret;
    case SYSRAWCONTEXT:
	long_ret = vmstat(rawcontext);
	return (u_char *)&long_ret;
    case CPURAWWAIT:
	if (!has_cpu_26) return NULL;
        long_ret = vmstat(cpurawwait);
        return ((u_char *) (&long_ret));
    case CPURAWINTR:
	if (!has_cpu_26) return NULL;
        long_ret = vmstat(cpurawinter);
        return ((u_char *) (&long_ret));
    case CPURAWSOFTIRQ:
	if (!has_cpu_26) return NULL;
        long_ret = vmstat(cpurawsoft);
        return ((u_char *) (&long_ret));
		
        /*
         * reserved for future use 
         */
        /*
         * case ERRORFLAG:
         * return((u_char *) (&long_ret));
         * case ERRORMSG:
         * return((u_char *) (&long_ret));
         */
    default:
	snmp_log(LOG_ERR, "vmstat.c: don't know how to handle %d request\n",
		vp->magic);
    }
    return NULL;
}