headscale/hscontrol/db/addresses.go

100 lines
2.2 KiB
Go

// Codehere is mostly taken from github.com/tailscale/tailscale
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package db
import (
"errors"
"fmt"
"net/netip"
"github.com/juanfont/headscale/hscontrol/types"
"github.com/juanfont/headscale/hscontrol/util"
"go4.org/netipx"
)
var ErrCouldNotAllocateIP = errors.New("could not find any suitable IP")
func (hsdb *HSDatabase) getAvailableIPs() (types.MachineAddresses, error) {
var ips types.MachineAddresses
var err error
for _, ipPrefix := range hsdb.ipPrefixes {
var ip *netip.Addr
ip, err = hsdb.getAvailableIP(ipPrefix)
if err != nil {
return ips, err
}
ips = append(ips, *ip)
}
return ips, err
}
func (hsdb *HSDatabase) getAvailableIP(ipPrefix netip.Prefix) (*netip.Addr, error) {
usedIps, err := hsdb.getUsedIPs()
if err != nil {
return nil, err
}
ipPrefixNetworkAddress, ipPrefixBroadcastAddress := util.GetIPPrefixEndpoints(ipPrefix)
// Get the first IP in our prefix
ip := ipPrefixNetworkAddress.Next()
for {
if !ipPrefix.Contains(ip) {
return nil, ErrCouldNotAllocateIP
}
switch {
case ip.Compare(ipPrefixBroadcastAddress) == 0:
fallthrough
case usedIps.Contains(ip):
fallthrough
case ip == netip.Addr{} || ip.IsLoopback():
ip = ip.Next()
continue
default:
return &ip, nil
}
}
}
func (hsdb *HSDatabase) getUsedIPs() (*netipx.IPSet, error) {
// FIXME: This really deserves a better data model,
// but this was quick to get running and it should be enough
// to begin experimenting with a dual stack tailnet.
var addressesSlices []string
hsdb.db.Model(&types.Machine{}).Pluck("ip_addresses", &addressesSlices)
var ips netipx.IPSetBuilder
for _, slice := range addressesSlices {
var machineAddresses types.MachineAddresses
err := machineAddresses.Scan(slice)
if err != nil {
return &netipx.IPSet{}, fmt.Errorf(
"failed to read ip from database: %w",
err,
)
}
for _, ip := range machineAddresses {
ips.Add(ip)
}
}
ipSet, err := ips.IPSet()
if err != nil {
return &netipx.IPSet{}, fmt.Errorf(
"failed to build IP Set: %w",
err,
)
}
return ipSet, nil
}