netbird/management/server/network.go
Mikhail Bragin be0c5c887c
Persist Network Serial to Store to avoid outdated netmap sent (#260)
Fix outdated update coming from management
even when it is actually not outdated.
2022-03-10 18:18:38 +01:00

114 lines
2.9 KiB
Go

package server
import (
"encoding/binary"
"fmt"
"github.com/rs/xid"
"net"
"sync"
)
var (
upperIPv4 = []byte{0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xff, 0xff, 255, 255, 255, 255}
upperIPv6 = []byte{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}
)
type NetworkMap struct {
Peers []*Peer
Network *Network
}
type Network struct {
Id string
Net net.IPNet
Dns string
// Serial is an ID that increments by 1 when any change to the network happened (e.g. new peer has been added).
// Used to synchronize state to the client apps.
Serial uint64
mu sync.Mutex `json:"-"`
}
// NewNetwork creates a new Network initializing it with a Serial=0
func NewNetwork() *Network {
return &Network{
Id: xid.New().String(),
Net: net.IPNet{IP: net.ParseIP("100.64.0.0"), Mask: net.IPMask{255, 192, 0, 0}},
Dns: "",
Serial: 0}
}
// IncSerial increments Serial by 1 reflecting that the network state has been changed
func (n *Network) IncSerial() {
n.mu.Lock()
defer n.mu.Unlock()
n.Serial = n.Serial + 1
}
// CurrentSerial returns the Network.Serial of the network (latest state id)
func (n *Network) CurrentSerial() uint64 {
n.mu.Lock()
defer n.mu.Unlock()
return n.Serial
}
func (n *Network) Copy() *Network {
return &Network{
Id: n.Id,
Net: n.Net,
Dns: n.Dns,
Serial: n.Serial,
}
}
// AllocatePeerIP pics an available IP from an net.IPNet.
// This method considers already taken IPs and reuses IPs if there are gaps in takenIps
// E.g. if ipNet=100.30.0.0/16 and takenIps=[100.30.0.1, 100.30.0.5] then the result would be 100.30.0.2
func AllocatePeerIP(ipNet net.IPNet, takenIps []net.IP) (net.IP, error) {
takenIpMap := make(map[string]net.IP)
takenIpMap[ipNet.IP.String()] = ipNet.IP
for _, ip := range takenIps {
takenIpMap[ip.String()] = ip
}
for ip := ipNet.IP.Mask(ipNet.Mask); ipNet.Contains(ip); ip = GetNextIP(ip) {
if _, ok := takenIpMap[ip.String()]; !ok {
return ip, nil
}
}
return nil, fmt.Errorf("failed allocating new IP for the ipNet %s and takenIps %s", ipNet.String(), takenIps)
}
// GetNextIP returns the next IP from the given IP address. If the given IP is
// the last IP of a v4 or v6 range, the same IP is returned.
// Credits to Cilium team.
// Copyright 2017-2020 Authors of Cilium
func GetNextIP(ip net.IP) net.IP {
if ip.Equal(upperIPv4) || ip.Equal(upperIPv6) {
return ip
}
nextIP := make(net.IP, len(ip))
switch len(ip) {
case net.IPv4len:
ipU32 := binary.BigEndian.Uint32(ip)
ipU32++
binary.BigEndian.PutUint32(nextIP, ipU32)
return nextIP
case net.IPv6len:
ipU64 := binary.BigEndian.Uint64(ip[net.IPv6len/2:])
ipU64++
binary.BigEndian.PutUint64(nextIP[net.IPv6len/2:], ipU64)
if ipU64 == 0 {
ipU64 = binary.BigEndian.Uint64(ip[:net.IPv6len/2])
ipU64++
binary.BigEndian.PutUint64(nextIP[:net.IPv6len/2], ipU64)
} else {
copy(nextIP[:net.IPv6len/2], ip[:net.IPv6len/2])
}
return nextIP
default:
return ip
}
}