1 #!/bin/bash
   2 set -e
   3 
   4 PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin
   5 
   6 #variables
   7 SYSCONFIG=/etc/sysconfig
   8 SCRIPTS=/etc/sysconfig/network-scripts
   9 BACKUPD=$SCRIPTS/backup-files
  10 INTERFACES=/etc/network/interfaces
  11 
  12 #functions
  13 
  14 cidr2mask() {
  15   local i mask=""
  16   local full_octets=$(($1/8))
  17   local partial_octet=$(($1%8))
  18 
  19   for ((i=0;i<4;i+=1)); do
  20     if [ $i -lt $full_octets ]; then
  21       mask+=255
  22     elif [ $i -eq $full_octets ]; then
  23       mask+=$((256 - 2**(8-$partial_octet)))
  24     else
  25       mask+=0
  26     fi
  27     test $i -lt 3 && mask+=.
  28   done
  29 
  30   echo $mask
  31 }
  32 
  33 
  34 get-current(){ #$1 =  optional ethernet device (defaults to eth0)
  35 #Use sed magic and function cidr2mask to convert ip command output to bash variables
  36 
  37 DEVICE=${1:-eth0}
  38 
  39 IPADDR=$(ip addr show $DEVICE|\
  40 sed -n  -e's%.*inet \([0-9]*\.[0-9]*\.[0-9]*\.[0-9]*\)/\([0-9]*\) brd.*scope global.*%\1%p')
  41 BROADCAST=$(ip addr show $DEVICE|\
  42 sed -n  -e's%.*inet.*brd \([0-9]*\.[0-9]*\.[0-9]*\.[0-9]*\) scope global.*%\1%p')
  43 NETMASK=$(ip addr show $DEVICE |\
  44 sed -n  -e's%.*inet [0-9]*\.[0-9]*\.[0-9]*\.[0-9]*/\([0-9]*\) brd.*scope global.*%\1\n%p' |\
  45         (read mask; if [ -n "$mask" ] ; then printf "%s\n" `cidr2mask $mask` ; fi))
  46 GATEWAY=$(ip route show |sed -n  -e's%default via \([0-9]*\.[0-9]*\.[0-9]*\.[0-9]*\) dev \(\w*\)\ .*%\1%p')
  47 #DOMAIN=$(cat /etc/resolv.conf | sed -e '/^#.*$/d' -e's/#.*//' | sed -n -e's%domain \(\w*\)%\1%p')
  48 DOMAIN=$(dnsdomainname)
  49 I present this here in the hope it helps someone else.
  50 NAMESERVERS=$(cat /etc/resolv.conf | sed -e '/^#.*$/d' -e's/#.*//' | sed -n -e's%nameserver \(\w*\)%\1%p')
  51 set -- $NAMESERVERS
  52 DNS1=$1
  53 DNS2=$2
  54 }
  55 
  56 get-hwaddr(){ #$1 =  optional ethernet device (defaults to eth0)
  57 DEVICE=${1:-eth0}
  58 ip addr show $DEVICE | sed -n  -e's%.*link/ether \([0-9A-F:].*\) brd.*%\1%p' | tr 'a-z' 'A-Z'
  59 }
  60 
  61 
  62 backup-files(){
  63 if [ -d $SCRIPTS ]; then #redhat
  64     cd $SYSCONFIG
  65     [ -f "$SYSCONFIG/network.orig" ] || cp -p "$SYSCONFIG/network" "$SYSCONFIG/network.orig"
  66     cp -p "$SYSCONFIG/network" "$SYSCONFIG/network-`date +%F-%T`"
  67 
  68     [ -d $BACKUPD ]  || mkdir $BACKUPD
  69     cd $SCRIPTS/
  70     for name in ifcfg-* ; do
  71     [ -f "$BACKUPD/${name}.orig" ] || cp -p "$name" "$BACKUPD/${name}.orig"
  72     cp -p "$name" "$BACKUPD/`date +%F-%T`-${name}"
  73     done
  74 fi
  75 if [ -f "${INTERFACES}" ] ; then #debian
  76     [ -f "${INTERFACES}.orig" ] || cp -p  "${INTERFACES}" "${INTERFACES}.orig"
  77     cp -p "${INTERFACES}" "${INTERFACES}-`date +%F-%T`"
  78 fi
  79 }
  80 
  81 fix-zeroconf(){
  82 if [ -d $SCRIPTS ]; then #redhat
  83     if ! grep -q "NOZEROCONF=yes" $SYSCONFIG/network ; then
  84         echo "NOZEROCONF=yes" >>$SYSCONFIG/network
  85     fi
  86 fi
  87 }
  88 
  89 fix-networkmanager(){
  90 local RUN
  91 RUN=""
  92 if $DEBUG ; then
  93    RUN="echo DEBUG: "
  94 fi
  95 if [ -d $SCRIPTS ]; then #redhat
  96     $RUN chkconfig NetworkManager off
  97     $RUN service   NetworkManager stop
  98     $RUN chkconfig network on
  99 fi
 100 }
 101 
 102 gen-ifcfg-dev-static(){ #$1 =  optional ethernet device (defaults to eth0)
 103 DEVICE=${1:-eth0}
 104 HWADDR=$(get-hwaddr $DEVICE)
 105 
 106 cat <<EOF >$SCRIPTS/ifcfg-$DEVICE
 107 DEVICE=$DEVICE
 108 
 109 NM_CONTROLLED=no
 110 #TYPE="Ethernet"
 111 #HWADDR=$HWADDR
 112 
 113 IPV6INIT=no
 114 
 115 ONBOOT=yes
 116 USERCTL=no
 117 BOOTPROTO=none
 118 
 119 IPADDR=$IPADDR
 120 NETMASK=$NETMASK
 121 BROADCAST=$BROADCAST
 122 GATEWAY=$GATEWAY
 123 DOMAIN=$DOMAIN
 124 DNS1=$DNS1
 125 DNS2=$DNS2
 126 EOF
 127 }
 128 
 129 
 130 gen-ifcfg-bond-static(){ #$1 = optional bond device (default bond0)
 131 DEVICE=${1:-bond0}
 132 
 133 cat <<EOF >$SCRIPTS/ifcfg-$DEVICE
 134 DEVICE=$DEVICE
 135 BONDING_OPTS="mode=4 miimon=100 xmit_hash_policy=layer3+4"
 136 
 137 NM_CONTROLLED=no
 138 #TYPE=Bond
 139 #BONDING_MASTER=yes
 140 
 141 IPV6INIT=no
 142 
 143 ONBOOT=yes
 144 USERCTL=no
 145 BOOTPROTO=none
 146 
 147 IPADDR=$IPADDR
 148 NETMASK=$NETMASK
 149 BROADCAST=$BROADCAST
 150 GATEWAY=$GATEWAY
 151 DOMAIN=$DOMAIN
 152 DNS1=$DNS1
 153 DNS2=$DNS2
 154 EOF
 155 
 156 }
 157 
 158 gen-ifcfg-bond-slave(){ #$1 =  optional ethernet device (defaults to eth0)
 159 DEVICE=${1:-eth0}
 160 HWADDR=$(get-hwaddr $DEVICE)
 161 
 162 if $DEBUG ; then
 163   echo DEBUG: gen-ifcfg-bond-slave dev $DEVICE mac $HWADDR
 164 fi
 165 
 166 cat <<EOF >$SCRIPTS/ifcfg-$DEVICE
 167 DEVICE=$DEVICE
 168 MASTER=bond0
 169 SLAVE=yes
 170 
 171 NM_CONTROLLED=no
 172 
 173 ONBOOT=yes
 174 USERCTL=no
 175 BOOTPROTO=none
 176 #HWADDR=$HWADDR
 177 #TYPE=Ethernet
 178 EOF
 179 }
 180 
 181 
 182 
 183 
 184 gen-interfaces-static(){
 185 DEVICE=${1:-eth0}
 186 cat <<EOF >"${INTERFACES}"
 187 # This file describes the network interfaces available on your system
 188 # and how to activate them. For more information, see interfaces(5).
 189 
 190 #source /etc/network/interfaces.d/*
 191 
 192 # The loopback network interface
 193 auto lo
 194 iface lo inet loopback
 195 
 196 # The primary network interface
 197 auto $DEVICE
 198 iface $DEVICE inet static
 199     address $IPADDR
 200     broadcast $BROADCAST
 201     netmask $NETMASK
 202     gateway $GATEWAY
 203     #dns-nameservers $DNS1 $DNS2
 204 
 205 EOF
 206 
 207 }
 208 
 209 gen-interfaces-bond-static(){
 210 DEVICE=${1:-bond0}
 211 cat <<EOF >"${INTERFACES}"
 212 # This file describes the network interfaces available on your system
 213 # and how to activate them. For more information, see interfaces(5).
 214 
 215 #source /etc/network/interfaces.d/*
 216 
 217 # The loopback network interface
 218 auto lo
 219 iface lo inet loopback
 220 
 221 # The primary network interface
 222 auto $DEVICE
 223 iface $DEVICE inet static
 224     address $IPADDR
 225     broadcast $BROADCAST
 226     netmask $NETMASK
 227     gateway $GATEWAY
 228     #dns-nameservers $DNS1 $DNS2
 229     slaves $slaves
 230     bond_mode 802.3ad
 231     bond_miimon 100
 232     bond_updelay 200
 233     bond_downdelay 200
 234     bond_xmit_hash_policy layer3+4
 235 EOF
 236 }
 237 
 238 #Main
 239 primary=eth0
 240 slaves="eth0 eth1"
 241 
 242 DEBUG=false
 243 RUN=""
 244 if [ "$1" = "--debug" ] ; then
 245     DEBUG=true
 246     shift
 247 
 248     RUN="echo DEUBG: "
 249     SYSCONFIG=/tmp/sysconfig
 250     SCRIPTS=/tmp/sysconfig/network-scripts
 251     BACKUPD=$SCRIPTS/backup-files
 252     INTERFACES=/tmp/network/interfaces
 253 
 254     echo "DEBUG MODE: altering files under /tmp not /etc"
 255 fi
 256 
 257 BOND=0
 258 if [ "$1" = "--bond" ] ; then
 259         BOND=1
 260         shift
 261 fi
 262 
 263 #Any further command line args are primary and secondary interfaces
 264 if [ $# -gt 0 ] ; then
 265     primary=$1
 266     shift
 267 fi
 268 
 269 if [ $# -gt 0 ] ; then
 270     secondaries="$*"
 271     slaves="$primary $secondaries"
 272 fi
 273 
 274 if $DEBUG ; then
 275    echo DEBUG: bond $BOND, primary $primary, secondaries $secondaries.
 276 fi
 277 
 278 
 279 
 280 backup-files
 281 get-current $primary
 282 fix-zeroconf
 283 fix-networkmanager
 284 
 285 $RUN ifdown $primary
 286 
 287 if [ -d $SCRIPTS ]; then #redhat
 288     if [ "$BOND" = "0"  ] ; then
 289         #single static device
 290         gen-ifcfg-dev-static $primary
 291     else
 292         #bonded static device
 293         gen-ifcfg-bond-static
 294         for dev in $slaves ; do
 295             gen-ifcfg-bond-slave $dev
 296         done
 297         $RUN ifconfig $primary 0.0.0.0
 298     fi
 299     #Start new network config
 300     $RUN service network restart
 301 fi
 302 
 303 if [ -f "${INTERFACES}" ] ; then #debian
 304     if [ "$BOND" = "0"  ] ; then
 305         #single static device
 306         gen-interfaces-static
 307         $RUN ifup $primary
 308     else
 309         #bonded static device
 310         gen-interfaces-bond-static
 311         $RUN ifconfig $primary 0.0.0.0
 312         $RUN ifup bond0
 313     fi
 314 fi