76 lines
2.7 KiB
Bash
Executable File
76 lines
2.7 KiB
Bash
Executable File
#!/bin/bash
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# Setup TAP/Bridge networking for QEMU VM
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# Defaults:
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# BRIDGE_NAME=br-rego-vpn
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# TAP_NAME=tap0
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# BRIDGE_CIDR=100.100.0.1/24
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# VM_NET_IP=100.100.0.2
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# VM_SUBNET=100.100.0.0/24
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set -e
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BRIDGE_NAME="${BRIDGE_NAME:-br-rego-vpn}"
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TAP_NAME="${TAP_NAME:-tap0}"
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BRIDGE_CIDR="${BRIDGE_CIDR:-100.100.0.1}"
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VM_NET_IP="${VM_NET_IP:-100.100.0.2}"
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VM_SUBNET="${VM_SUBNET:-100.100.0.0}"
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TARGET_IP="${TARGET_IP:-10.35.33.230}"
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if [[ "$BRIDGE_CIDR" != */* ]]; then
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BRIDGE_CIDR="$BRIDGE_CIDR/24"
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fi
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if [[ "$VM_SUBNET" != */* ]]; then
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VM_SUBNET="$VM_SUBNET/24"
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fi
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# Pick the outbound interface based on the container's default route.
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# (In Docker, this is not always eth1 when multiple networks are attached.)
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WAN_IF="$(ip route show default 0.0.0.0/0 2>/dev/null | awk '{for(i=1;i<=NF;i++) if($i=="dev"){print $(i+1); exit}}')"
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if [ -z "${WAN_IF}" ]; then
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WAN_IF="eth1"
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fi
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# Create bridge if not exists
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if ! ip link show "$BRIDGE_NAME" &>/dev/null; then
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ip link add "$BRIDGE_NAME" type bridge
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ip addr add "$BRIDGE_CIDR" dev "$BRIDGE_NAME"
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ip link set "$BRIDGE_NAME" up
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echo "Bridge $BRIDGE_NAME created with IP $BRIDGE_CIDR"
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fi
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# Create TAP device if not exists
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if ! ip link show "$TAP_NAME" &>/dev/null; then
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ip tuntap add "$TAP_NAME" mode tap
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ip link set "$TAP_NAME" master "$BRIDGE_NAME"
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ip link set "$TAP_NAME" up
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echo "TAP device $TAP_NAME created and attached to $BRIDGE_NAME"
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fi
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# Enable IP forwarding
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echo 1 > /proc/sys/net/ipv4/ip_forward
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# Setup NAT/masquerade for outbound traffic from VM
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iptables -t nat -C POSTROUTING -s "$VM_SUBNET" -o "$WAN_IF" -j MASQUERADE 2>/dev/null || \
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iptables -t nat -A POSTROUTING -s "$VM_SUBNET" -o "$WAN_IF" -j MASQUERADE
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# Ensure forwarding between the VM bridge and outbound interface
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iptables -C FORWARD -i "$BRIDGE_NAME" -o "$WAN_IF" -j ACCEPT 2>/dev/null || \
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iptables -A FORWARD -i "$BRIDGE_NAME" -o "$WAN_IF" -j ACCEPT
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iptables -C FORWARD -i "$WAN_IF" -o "$BRIDGE_NAME" -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT 2>/dev/null || \
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iptables -A FORWARD -i "$WAN_IF" -o "$BRIDGE_NAME" -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
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# Forward traffic destined for VPN networks to VM (TARGET_IP defaults to IBM i)
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# The VM will route this through its VPN tunnel
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iptables -C FORWARD -d "$TARGET_IP" -j ACCEPT 2>/dev/null || iptables -A FORWARD -d "$TARGET_IP" -j ACCEPT
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iptables -C FORWARD -s "$TARGET_IP" -j ACCEPT 2>/dev/null || iptables -A FORWARD -s "$TARGET_IP" -j ACCEPT
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# Route to TARGET_IP through VM
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ip route add "$TARGET_IP" via "$VM_NET_IP" 2>/dev/null || true
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echo "Network setup complete"
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echo "Bridge: $BRIDGE_NAME = $BRIDGE_CIDR"
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echo "TAP: $TAP_NAME attached to $BRIDGE_NAME"
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echo "Route: $TARGET_IP via $VM_NET_IP (VM)"
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echo "Outbound interface: ${WAN_IF}"
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