Server Yönetimi İçin Yararlı Kodlar

iptables -A INPUT -s Banlanacak_Ip_Adresi -j DROP

netstat -ntu | grep :80 | awk '{print $6}' | cut -f1 -d ':' |sort| uniq -c | sort -n;

netstat -ntu | grep :80 | awk '{print $5}' | cut -f1 -d ':' |sort| uniq -c | sort -n | awk '$1 > 10 {print $1,$2}'

echo `netstat -an|wc -l`

echo `uptime | awk -F "load average: " '{ print $2 }' | cut -d, -f1`

sysctl -w net.ipv4.icmp_echo_ignore_all=1

sysctl -w net.ipv4.icmp_echo_ignore_all=0

netstat -ntu |grep SYN | awk '{print $5}' | awk '{sub("::ffff:","");print}' | cut -f1 -d ':' | sort | uniq -c | sort -n | grep -v -e server -e Address -e 127.0.0.1 -e 0.0.0.0

#!/bin/sh

# Saldiri varmi ?
SYNCOUNT=`netstat -n | grep SYN | wc -l`

if [ $SYNCOUNT -gt 20 ] ; then

echo "$SYNCOUNT SYN Bulundu! Banlama basliyor lutfen bekleyin."

# Sunucu iplerini beyaz liste alalim.
ip addr show|grep inet|grep -v 127.0.0.1|grep -v inet6|awk '{print $2}'|cut -d: -f9|cut -d/ -f1|while read ipler; do touch /tmp/$ipler.tk; done

# Bloklanicak Paket Sayisi
#Default deger BPAKET=40
BPAKET=40
# Incelenecek Paket Sayisi
# Default deger SPAKET=5000
SPAKET=5000
# Inceleyelim.
tcpdump -n -q -c $SPAKET 'tcp[tcpflags] & tcp-syn != 0 and dst port 80'| awk '{print $3}'|awk -F. -v n=. '{print $1 n $2 n $3 n $4}'|sort|uniq -c|sort -nr|awk '$1 > $PAKET'|awk '{print $2}'|while read ipler;
do if [ ! -f /tmp/$ipler.tk ]; then
touch /tmp/$ipler.tk && iptables -A INPUT -s $ipler -j DROP && echo $ipler blokladim;
fi
done

# Cikalim.
else
echo "$SYNCOUNT SYN Bulundu! Saldiri tespit edilmedi..."
fi
exit 0

#/usr/bin/!
# Sistem Load Degeri load="" arasindaki degeri astiginda program calisip servislerinize reset atacak
load="60"


######### Resetlenecek servisler baslar #########
loadkomutu=`uptime | awk -F "load average: " '{ print $2 }' | cut -d, -f1 | cut -d. -f1`
mailload=`uptime | awk -F "load average: " '{ print $2 }' | cut -d, -f1`

if [ "$loadkomutu" -ge "$load" ]
then
######### Resetlenecek servisler baslar #########
pkill -9 httpd
######### Resetlenecek servisler biter #########

zaman=`date +"%d.%m.%Y - %T"`
echo "Servisler en son su tarihte yeniden baslatildi : $zaman" >> /var/log/kontrol.load

TMP_PREFIX='/tmp/gidenmail'
TMP_FILE="mktemp $TMP_PREFIX.XXXXXXXX"
mailicerigi=`$TMP_FILE`

echo "Tarih : $zaman" > $mailicerigi
echo "Sistem Load Yuksek: $mailload" >> $mailicerigi

cat "$mailicerigi" |  mail -s "$zaman UYARI: Yuksek Load $mailload" $1

else
echo "Sorun yok"
/etc/init.d/httpd start
fi

#! /bin/bash
#List processes based on %cpu and memory usage

echo “Start Time” `date`
# By default, it display the list of processes based on the cpu and memory usage #
if [ $# -eq 0 ]
then

    echo “List of processes based on the %cpu Usage”
    ps -e -o pcpu,cpu,nice,state,cputime,args –sort pcpu  # sorted based on %cpu
    echo “List of processes based on the memory Usage”
    ps -e -orss=,args= | sort -b -k1,1n # sorted bases rss value

# If arguements are given (mem/cpu)
else
    case “$1¨ in
    mem)
     echo “List of processes based on the memory Usage”
      ps -e -orss=,args= | sort -b -k1,1n
     ;;
     cpu)
     echo “List of processes based on the %cpu Usage”
     ps -e -o pcpu,cpu,nice,state,cputime,args –sort pcpu
     ;;
     *)
        echo “Invalid Argument Given \n”
        echo “Usage : $0 mem/cpu”
        exit 1
     esac    

fi
echo “End Time” `date`
exit 0

#! /bin/bash

w > /tmp/a

echo “Total number of unique users logged in currently”
cat /tmp/a|  sed ’1,2d’ | awk ‘{print $1}’ | uniq | wc -l
echo “”

echo “List of unique users logged in currently”
cat /tmp/a | sed ’1,2d’|  awk ‘{print $1}’ | uniq
echo “”

echo “The user who is using high %cpu”
cat /tmp/a | sed ’1,2d’ | awk   ‘$7 > maxuid { maxuid=$7; maxline=$0 }; END { print maxuid, maxline }’ 

echo “”
echo “List of users logged in and what they are doing”
cat /tmp/a

#! /bin/bash

# Total memory space details

echo “Memory Space Details”
free -t -m | grep “Total” | awk ‘{ print “Total Memory space : “$2 ” MB”;
print “Used Memory Space : “$3¨ MB”;
print “Free Memory : “$4¨ MB”;
}’

echo “Swap memory Details”
free -t -m | grep “Swap” | awk ‘{ print “Total Swap space : “$2 ” MB”;
print “Used Swap Space : “$3¨ MB”;
print “Free Swap : “$4¨ MB”;
}’