arv-v-dsm/network.sh
2023-04-14 01:35:17 +02:00

104 lines
3.6 KiB
Bash

#!/usr/bin/env bash
set -eu
: ${VM_NET_TAP:=''}
: ${VM_NET_IP:='20.20.20.21'}
: ${VM_NET_MAC:='02:11:32:AA:BB:CC'}
: ${DNS_SERVERS:=''}
: ${DNSMASQ:='/usr/sbin/dnsmasq'}
: ${DNSMASQ_OPTS:=''}
: ${DNSMASQ_CONF_DIR:='/etc/dnsmasq.d'}
# ######################################
# Functions
# ######################################
# Setup macvtap device to connect later the VM and setup a new macvlan device to connect the host machine to the network
configureNatNetworks () {
#Create bridge with static IP for the VM guest
brctl addbr dockerbridge
ip addr add ${VM_NET_IP%.*}.1/24 broadcast ${VM_NET_IP%.*}.255 dev dockerbridge
ip link set dockerbridge up
#QEMU Works with taps, set tap to the bridge created
ip tuntap add dev ${VM_NET_TAP} mode tap
ip link set ${VM_NET_TAP} up promisc on
brctl addif dockerbridge ${VM_NET_TAP}
#Add internet connection to the VM
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
iptables -t nat -A PREROUTING -i eth0 -p tcp -j DNAT --to $VM_NET_IP
iptables -t nat -A PREROUTING -i eth0 -p udp -j DNAT --to $VM_NET_IP
#Enable port forwarding flag
[[ $(< /proc/sys/net/ipv4/ip_forward) -eq 0 ]] && sysctl -w net.ipv4.ip_forward=1
CIDR="24"
HOSTNAME="VirtualDSM"
# dnsmasq configuration:
DNSMASQ_OPTS="$DNSMASQ_OPTS --dhcp-range=$VM_NET_IP,$VM_NET_IP --dhcp-host=$VM_NET_MAC,,$VM_NET_IP,$HOSTNAME,infinite --dhcp-option=option:netmask,255.255.255.0"
# Create lease file for faster resolve
echo "0 $VM_NET_MAC $VM_NET_IP $HOSTNAME 01:${VM_NET_MAC}" > /var/lib/misc/dnsmasq.leases
chmod 644 /var/lib/misc/dnsmasq.leases
}
# ######################################
# Configure Network
# ######################################
# Create the necessary file structure for /dev/net/tun
if [ ! -c /dev/net/tun ]; then
[ ! -d /dev/net ] && mkdir -m 755 /dev/net
mknod /dev/net/tun c 10 200
chmod 666 /dev/net/tun
fi
[ ! -c /dev/net/tun ] && echo "Error: TUN network interface not available..." && exit 85
update-alternatives --set iptables /usr/sbin/iptables-legacy > /dev/null
update-alternatives --set ip6tables /usr/sbin/ip6tables-legacy > /dev/null
VM_NET_TAP="_VmNatTap"
configureNatNetworks
KVM_NET_OPTS="-netdev tap,ifname=${VM_NET_TAP},script=no,downscript=no,id=hostnet0"
# Build DNS options from container /etc/resolv.conf
nameservers=($(grep '^nameserver' /etc/resolv.conf | sed 's/nameserver //'))
searchdomains=$(grep '^search' /etc/resolv.conf | sed 's/search //' | sed 's/ /,/g')
domainname=$(echo $searchdomains | awk -F"," '{print $1}')
for nameserver in "${nameservers[@]}"; do
if ! [[ $nameserver =~ .*:.* ]]; then
[[ -z $DNS_SERVERS ]] && DNS_SERVERS=$nameserver || DNS_SERVERS="$DNS_SERVERS,$nameserver"
fi
done
if [ -z $DNS_SERVERS ]; then
DNS_SERVERS="1.1.1.1"
else
COMMAS=${DNS_SERVERS//[^,]/}
COMMAS=${#COMMAS}
((COMMAS < 1)) && DNS_SERVERS="$DNS_SERVERS,1.1.1.1"
fi
DNSMASQ_OPTS="$DNSMASQ_OPTS \
--dhcp-option=option:dns-server,$DNS_SERVERS \
--dhcp-option=option:router,${VM_NET_IP%.*}.1"
if [ -n "$searchdomains" -a "$searchdomains" != "." ]; then
DNSMASQ_OPTS="$DNSMASQ_OPTS --dhcp-option=option:domain-search,$searchdomains"
DNSMASQ_OPTS="$DNSMASQ_OPTS --dhcp-option=option:domain-name,$domainname"
else
[[ -z $(hostname -d) ]] || DNSMASQ_OPTS="$DNSMASQ_OPTS --dhcp-option=option:domain-name,$(hostname -d)"
fi
$DNSMASQ $DNSMASQ_OPTS
KVM_NET_OPTS="${KVM_NET_OPTS} -device virtio-net-pci,romfile=,netdev=hostnet0,mac=${VM_NET_MAC},id=net0"
# Hack for guest VMs complaining about "bad udp checksums in 5 packets"
iptables -A POSTROUTING -t mangle -p udp --dport bootpc -j CHECKSUM --checksum-fill