我们如何在Linux中动态更新MIB变量值？

Question

我创建了一个MIB文件，其中添加了五个变量。另外，通过使用以下命令，

snmptranslate -m +GET-LATEST-SIGNALS-MIB -IR -On oversightInteger

我可以看到所有Varialbes的OID。

之后，通过使用“通过协议”，我尝试借助关注脚本文件从一个变量中获取数据

#!/bin/sh -f

PLACE=".1.3.6.1.4.1.53864.1.1"
REQ="$2"    # Requested OID

#
#  Process SET requests by simply logging the assigned value
#      Note that such "assignments" are not persistent,
#      nor is the syntax or requested value validated
#
if [ "$1" = "-s" ]; then
  echo $* >> /tmp/passtest.log
  exit 0
fi

#
#  GETNEXT requests - determine next valid instance
#
if [ "$1" = "-n" ]; then
  case "$REQ" in
    $PLACE|             \
    $PLACE.0|           \
    $PLACE.0.*|         \
    $PLACE.1)       RET=$PLACE.1.0 ;;     # netSnmpPassString.0

    $PLACE.1.*|         \
    $PLACE.2|           \
    $PLACE.2.0|         \
    $PLACE.2.0.*|       \
    $PLACE.2.1|         \
    $PLACE.2.1.0|       \
    $PLACE.2.1.0.*|     \
    $PLACE.2.1.1|       \
    $PLACE.2.1.1.*|     \
    $PLACE.2.1.2|       \
    $PLACE.2.1.2.0) RET=$PLACE.2.1.2.1 ;; # netSnmpPassInteger.1

    $PLACE.2.1.2.*|     \
    $PLACE.2.1.3|       \
    $PLACE.2.1.3.0) RET=$PLACE.2.1.3.1 ;; # netSnmpPassOID.1

    $PLACE.2.*|         \
    $PLACE.3)       RET=$PLACE.3.0 ;;     # netSnmpPassTimeTicks.0
    $PLACE.3.*|         \
    $PLACE.4)       RET=$PLACE.4.0 ;;     # netSnmpPassIpAddress.0
    $PLACE.4.*|         \
    $PLACE.5)       RET=$PLACE.5.0 ;;     # netSnmpPassCounter.0
    $PLACE.5.*|         \
    $PLACE.6)       RET=$PLACE.6.0 ;;     # netSnmpPassGauge.0

    *)              exit 0 ;;
  esac
else
#
#  GET requests - check for valid instance
#
  case "$REQ" in
    $PLACE.1.0|         \
    $PLACE.2.1.2.1|     \
    $PLACE.2.1.3.1|     \
    $PLACE.3.0|         \
    $PLACE.4.0|         \
    $PLACE.5.0|         \
    $PLACE.6.0)     RET=$REQ ;;
    *)              exit 0 ;;
  esac
fi

#
#  "Process" GET* requests - return hard-coded value
#
echo "$RET"
case "$RET" in
  $PLACE.1.0)     echo "string";    echo "Life, the Universe, and Everything"; exit 0 ;;
  $PLACE.2.1.2.1) echo "integer";   echo "42";                                 exit 0 ;;
  $PLACE.2.1.3.1) echo "objectid";  echo "$PLACE.99";                          exit 0 ;;
  $PLACE.3.0)     echo "timeticks"; echo "363136200";                          exit 0 ;;
  $PLACE.4.0)     echo "ipaddress"; echo "127.0.0.1";                          exit 0 ;;
  $PLACE.5.0)     echo "counter";   echo "42";                                 exit 0 ;;
  $PLACE.6.0)     echo "gauge";     echo "42";                                 exit 0 ;;
  *)              echo "string";    echo "ack... $RET $REQ";                   exit 0 ;;  # Should not happen
esac

运行上面的脚本文件后，我使用以下命令

snmpwalk -v2c localhost -c public .1.3.6.1.4.1.53864

和输出，

GET-LATEST-SIGNALS-MIB::oversightInteger.1.0 = STRING: "Life, the 
Universe, and Everything"
GET-LATEST-SIGNALS-MIB::oversightInteger.2.1.2.1 = Wrong Type 
(should be OCTET STRING): INTEGER: 42
GET-LATEST-SIGNALS-MIB::oversightInteger.2.1.3.1 = Wrong Type 
(should be OCTET STRING): OID: GET-LATEST-SIGNALS- 
MIB::oversightInteger.99
GET-LATEST-SIGNALS-MIB::oversightInteger.3.0 = Wrong Type (should 
be OCTET STRING): Timeticks: (363136200) 42 days, 0:42:42.00
GET-LATEST-SIGNALS-MIB::oversightInteger.4.0 = Wrong Type (should 
be OCTET STRING): IpAddress: 127.0.0.1
GET-LATEST-SIGNALS-MIB::oversightInteger.5.0 = Wrong Type (should  
e OCTET STRING): Counter32: 42
GET-LATEST-SIGNALS-MIB::oversightInteger.6.0 = Wrong Type (should 
be OCTET STRING): Gauge32: 42

因此现在我想动态地更改“生命，宇宙和所有内容”的值，以便我们如何动态地更改OID值？

我现在呆了将近2周，所以任何帮助都将不胜感激！！

Answer 1

因此，要解决此问题，我包括sqlite3数据库。

现在，每当我们在嵌入式C应用程序（将始终在后面运行）中获取最新值时，我们在数据库中更新该值，因此IF之间接收任何请求，例如设置，获取等，然后脚本将读取数据库以获取MIB Varialbes的最新值，并将发送到MIB浏览器。

我们在脚本中使用以下命令来从数据库中获取数据

echo "$(sqlite3 /home/root/database/pdu.db <<'END_SQL'
.timeout 2000
SELECT Variable_Value FROM Data Where Sr_No='2';
END_SQL)