headscale/hscontrol/db/addresses.go
Kristoffer Dalby 83769ba715
Replace database locks with transactions (#1701)
This commits removes the locks used to guard data integrity for the
database and replaces them with Transactions, turns out that SQL had
a way to deal with this all along.

This reduces the complexity we had with multiple locks that might stack
or recurse (database, nofitifer, mapper). All notifications and state
updates are now triggered _after_ a database change.


Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
2024-02-08 17:28:19 +01:00

107 lines
2.4 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"
"gorm.io/gorm"
)
var ErrCouldNotAllocateIP = errors.New("could not find any suitable IP")
func (hsdb *HSDatabase) getAvailableIPs() (types.NodeAddresses, error) {
return Read(hsdb.DB, func(rx *gorm.DB) (types.NodeAddresses, error) {
return getAvailableIPs(rx, hsdb.ipPrefixes)
})
}
func getAvailableIPs(rx *gorm.DB, ipPrefixes []netip.Prefix) (types.NodeAddresses, error) {
var ips types.NodeAddresses
var err error
for _, ipPrefix := range ipPrefixes {
var ip *netip.Addr
ip, err = getAvailableIP(rx, ipPrefix)
if err != nil {
return ips, err
}
ips = append(ips, *ip)
}
return ips, err
}
func getAvailableIP(rx *gorm.DB, ipPrefix netip.Prefix) (*netip.Addr, error) {
usedIps, err := getUsedIPs(rx)
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 getUsedIPs(rx *gorm.DB) (*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
rx.Model(&types.Node{}).Pluck("ip_addresses", &addressesSlices)
var ips netipx.IPSetBuilder
for _, slice := range addressesSlices {
var machineAddresses types.NodeAddresses
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
}