metadata-api: support dnsmasq (#3115)

hack/qemu-metadata-api/dhcp/virtwrapper/virtwrapper_cgo.go

@@ -0,0 +1,60 @@
+//go:build cgo
+
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package virtwrapper
+
+import (
+	"github.com/edgelesssys/constellation/v2/hack/qemu-metadata-api/dhcp"
+
+	"libvirt.org/go/libvirt"
+)
+
+// Connect wraps a libvirt connection.
+type Connect struct {
+	conn        *libvirt.Connect
+	networkName string
+}
+
+// New creates a new libvirt Connct wrapper.
+func New(conn *libvirt.Connect, networkName string) *Connect {
+	return &Connect{
+		conn:        conn,
+		networkName: networkName,
+	}
+}
+
+// LookupNetworkByName looks up a network by name.
+func (c *Connect) lookupNetworkByName(name string) (*libvirt.Network, error) {
+	net, err := c.conn.LookupNetworkByName(name)
+	if err != nil {
+		return nil, err
+	}
+	return net, nil
+}
+
+// GetDHCPLeases returns the underlying DHCP leases.
+func (c *Connect) GetDHCPLeases() ([]dhcp.NetworkDHCPLease, error) {
+	net, err := c.lookupNetworkByName(c.networkName)
+	if err != nil {
+		return nil, err
+	}
+	defer net.Free()
+
+	leases, err := net.GetDHCPLeases()
+	if err != nil {
+		return nil, err
+	}
+	ret := make([]dhcp.NetworkDHCPLease, len(leases))
+	for i, l := range leases {
+		ret[i] = dhcp.NetworkDHCPLease{
+			IPaddr:   l.IPaddr,
+			Hostname: l.Hostname,
+		}
+	}
+	return ret, nil
+}