mirror of
https://github.com/netbirdio/netbird.git
synced 2024-12-15 11:21:04 +01:00
148 lines
3.5 KiB
Go
148 lines
3.5 KiB
Go
package server
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import (
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"math/rand"
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"net"
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"sync"
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"time"
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"github.com/c-robinson/iplib"
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"github.com/rs/xid"
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nbdns "github.com/netbirdio/netbird/dns"
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"github.com/netbirdio/netbird/management/server/status"
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"github.com/netbirdio/netbird/route"
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)
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const (
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// SubnetSize is a size of the subnet of the global network, e.g. 100.77.0.0/16
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SubnetSize = 16
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// NetSize is a global network size 100.64.0.0/10
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NetSize = 10
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// AllowedIPsFormat generates Wireguard AllowedIPs format (e.g. 100.64.30.1/32)
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AllowedIPsFormat = "%s/32"
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)
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type NetworkMap struct {
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Peers []*Peer
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Network *Network
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Routes []*route.Route
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DNSConfig nbdns.Config
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OfflinePeers []*Peer
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FirewallRules []*FirewallRule
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}
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type Network struct {
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Id string
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Net net.IPNet
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Dns string
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// Serial is an ID that increments by 1 when any change to the network happened (e.g. new peer has been added).
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// Used to synchronize state to the client apps.
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Serial uint64
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mu sync.Mutex `json:"-"`
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}
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// NewNetwork creates a new Network initializing it with a Serial=0
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// It takes a random /16 subnet from 100.64.0.0/10 (64 different subnets)
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func NewNetwork() *Network {
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n := iplib.NewNet4(net.ParseIP("100.64.0.0"), NetSize)
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sub, _ := n.Subnet(SubnetSize)
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s := rand.NewSource(time.Now().Unix())
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r := rand.New(s)
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intn := r.Intn(len(sub))
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return &Network{
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Id: xid.New().String(),
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Net: sub[intn].IPNet,
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Dns: "",
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Serial: 0}
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}
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// IncSerial increments Serial by 1 reflecting that the network state has been changed
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func (n *Network) IncSerial() {
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n.mu.Lock()
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defer n.mu.Unlock()
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n.Serial = n.Serial + 1
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}
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// CurrentSerial returns the Network.Serial of the network (latest state id)
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func (n *Network) CurrentSerial() uint64 {
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n.mu.Lock()
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defer n.mu.Unlock()
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return n.Serial
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}
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func (n *Network) Copy() *Network {
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return &Network{
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Id: n.Id,
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Net: n.Net,
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Dns: n.Dns,
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Serial: n.Serial,
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}
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}
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// AllocatePeerIP pics an available IP from an net.IPNet.
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// This method considers already taken IPs and reuses IPs if there are gaps in takenIps
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// E.g. if ipNet=100.30.0.0/16 and takenIps=[100.30.0.1, 100.30.0.4] then the result would be 100.30.0.2 or 100.30.0.3
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func AllocatePeerIP(ipNet net.IPNet, takenIps []net.IP) (net.IP, error) {
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takenIPMap := make(map[string]struct{})
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takenIPMap[ipNet.IP.String()] = struct{}{}
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for _, ip := range takenIps {
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takenIPMap[ip.String()] = struct{}{}
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}
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ips, _ := generateIPs(&ipNet, takenIPMap)
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if len(ips) == 0 {
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return nil, status.Errorf(status.PreconditionFailed, "failed allocating new IP for the ipNet %s - network is out of IPs", ipNet.String())
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}
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// pick a random IP
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s := rand.NewSource(time.Now().Unix())
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r := rand.New(s)
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intn := r.Intn(len(ips))
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return ips[intn], nil
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}
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// generateIPs generates a list of all possible IPs of the given network excluding IPs specified in the exclusion list
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func generateIPs(ipNet *net.IPNet, exclusions map[string]struct{}) ([]net.IP, int) {
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var ips []net.IP
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for ip := ipNet.IP.Mask(ipNet.Mask); ipNet.Contains(ip); incIP(ip) {
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if _, ok := exclusions[ip.String()]; !ok && ip[3] != 0 {
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ips = append(ips, copyIP(ip))
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}
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}
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// remove network address, broadcast and Fake DNS resolver address
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lenIPs := len(ips)
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switch {
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case lenIPs < 2:
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return ips, lenIPs
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case lenIPs < 3:
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return ips[1 : len(ips)-1], lenIPs - 2
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default:
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return ips[1 : len(ips)-2], lenIPs - 3
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}
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}
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func copyIP(ip net.IP) net.IP {
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dup := make(net.IP, len(ip))
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copy(dup, ip)
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return dup
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}
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func incIP(ip net.IP) {
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for j := len(ip) - 1; j >= 0; j-- {
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ip[j]++
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if ip[j] > 0 {
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break
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}
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}
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}
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