mirror of
https://github.com/yggdrasil-network/yggdrasil-go.git
synced 2025-11-04 03:05:07 +03:00
Add crypto-key routing into TUN/TAP
This commit is contained in:
Neil Alexander
parent
9c01947b1c
commit
71ccaf753e
3 changed files with 436 additions and 31 deletions
411
src/tuntap/ckr.go
Normal file
411
src/tuntap/ckr.go
Normal file
|
|
@ -0,0 +1,411 @@
|
|||
package tuntap
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"encoding/hex"
|
||||
"errors"
|
||||
"fmt"
|
||||
"net"
|
||||
"sort"
|
||||
|
||||
"github.com/yggdrasil-network/yggdrasil-go/src/address"
|
||||
"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
|
||||
)
|
||||
|
||||
// This module implements crypto-key routing, similar to Wireguard, where we
|
||||
// allow traffic for non-Yggdrasil ranges to be routed over Yggdrasil.
|
||||
|
||||
type cryptokey struct {
|
||||
tun *TunAdapter
|
||||
enabled bool
|
||||
reconfigure chan chan error
|
||||
ipv4routes []cryptokey_route
|
||||
ipv6routes []cryptokey_route
|
||||
ipv4cache map[address.Address]cryptokey_route
|
||||
ipv6cache map[address.Address]cryptokey_route
|
||||
ipv4sources []net.IPNet
|
||||
ipv6sources []net.IPNet
|
||||
}
|
||||
|
||||
type cryptokey_route struct {
|
||||
subnet net.IPNet
|
||||
destination crypto.BoxPubKey
|
||||
}
|
||||
|
||||
// Initialise crypto-key routing. This must be done before any other CKR calls.
|
||||
func (c *cryptokey) init(tun *TunAdapter) {
|
||||
c.tun = tun
|
||||
c.reconfigure = make(chan chan error, 1)
|
||||
go func() {
|
||||
for {
|
||||
e := <-c.reconfigure
|
||||
e <- nil
|
||||
}
|
||||
}()
|
||||
|
||||
if err := c.configure(); err != nil {
|
||||
c.tun.log.Errorln("CKR configuration failed:", err)
|
||||
}
|
||||
}
|
||||
|
||||
// Configure the CKR routes - this must only ever be called from the router
|
||||
// goroutine, e.g. through router.doAdmin
|
||||
func (c *cryptokey) configure() error {
|
||||
c.tun.config.Mutex.RLock()
|
||||
defer c.tun.config.Mutex.RUnlock()
|
||||
|
||||
// Set enabled/disabled state
|
||||
c.setEnabled(c.tun.config.Current.TunnelRouting.Enable)
|
||||
|
||||
// Clear out existing routes
|
||||
c.ipv6routes = make([]cryptokey_route, 0)
|
||||
c.ipv4routes = make([]cryptokey_route, 0)
|
||||
|
||||
// Add IPv6 routes
|
||||
for ipv6, pubkey := range c.tun.config.Current.TunnelRouting.IPv6Destinations {
|
||||
if err := c.addRoute(ipv6, pubkey); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
||||
// Add IPv4 routes
|
||||
for ipv4, pubkey := range c.tun.config.Current.TunnelRouting.IPv4Destinations {
|
||||
if err := c.addRoute(ipv4, pubkey); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
||||
// Clear out existing sources
|
||||
c.ipv6sources = make([]net.IPNet, 0)
|
||||
c.ipv4sources = make([]net.IPNet, 0)
|
||||
|
||||
// Add IPv6 sources
|
||||
c.ipv6sources = make([]net.IPNet, 0)
|
||||
for _, source := range c.tun.config.Current.TunnelRouting.IPv6Sources {
|
||||
if err := c.addSourceSubnet(source); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
||||
// Add IPv4 sources
|
||||
c.ipv4sources = make([]net.IPNet, 0)
|
||||
for _, source := range c.tun.config.Current.TunnelRouting.IPv4Sources {
|
||||
if err := c.addSourceSubnet(source); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
||||
// Wipe the caches
|
||||
c.ipv4cache = make(map[address.Address]cryptokey_route, 0)
|
||||
c.ipv6cache = make(map[address.Address]cryptokey_route, 0)
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// Enable or disable crypto-key routing.
|
||||
func (c *cryptokey) setEnabled(enabled bool) {
|
||||
c.enabled = enabled
|
||||
}
|
||||
|
||||
// Check if crypto-key routing is enabled.
|
||||
func (c *cryptokey) isEnabled() bool {
|
||||
return c.enabled
|
||||
}
|
||||
|
||||
// Check whether the given address (with the address length specified in bytes)
|
||||
// matches either the current node's address, the node's routed subnet or the
|
||||
// list of subnets specified in IPv4Sources/IPv6Sources.
|
||||
func (c *cryptokey) isValidSource(addr address.Address, addrlen int) bool {
|
||||
ip := net.IP(addr[:addrlen])
|
||||
|
||||
if addrlen == net.IPv6len {
|
||||
// Does this match our node's address?
|
||||
if bytes.Equal(addr[:16], c.tun.addr[:16]) {
|
||||
return true
|
||||
}
|
||||
|
||||
// Does this match our node's subnet?
|
||||
if bytes.Equal(addr[:8], c.tun.subnet[:8]) {
|
||||
return true
|
||||
}
|
||||
}
|
||||
|
||||
// Does it match a configured CKR source?
|
||||
if c.isEnabled() {
|
||||
// Build our references to the routing sources
|
||||
var routingsources *[]net.IPNet
|
||||
|
||||
// Check if the prefix is IPv4 or IPv6
|
||||
if addrlen == net.IPv6len {
|
||||
routingsources = &c.ipv6sources
|
||||
} else if addrlen == net.IPv4len {
|
||||
routingsources = &c.ipv4sources
|
||||
} else {
|
||||
return false
|
||||
}
|
||||
|
||||
for _, subnet := range *routingsources {
|
||||
if subnet.Contains(ip) {
|
||||
return true
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Doesn't match any of the above
|
||||
return false
|
||||
}
|
||||
|
||||
// Adds a source subnet, which allows traffic with these source addresses to
|
||||
// be tunnelled using crypto-key routing.
|
||||
func (c *cryptokey) addSourceSubnet(cidr string) error {
|
||||
// Is the CIDR we've been given valid?
|
||||
_, ipnet, err := net.ParseCIDR(cidr)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// Get the prefix length and size
|
||||
_, prefixsize := ipnet.Mask.Size()
|
||||
|
||||
// Build our references to the routing sources
|
||||
var routingsources *[]net.IPNet
|
||||
|
||||
// Check if the prefix is IPv4 or IPv6
|
||||
if prefixsize == net.IPv6len*8 {
|
||||
routingsources = &c.ipv6sources
|
||||
} else if prefixsize == net.IPv4len*8 {
|
||||
routingsources = &c.ipv4sources
|
||||
} else {
|
||||
return errors.New("Unexpected prefix size")
|
||||
}
|
||||
|
||||
// Check if we already have this CIDR
|
||||
for _, subnet := range *routingsources {
|
||||
if subnet.String() == ipnet.String() {
|
||||
return errors.New("Source subnet already configured")
|
||||
}
|
||||
}
|
||||
|
||||
// Add the source subnet
|
||||
*routingsources = append(*routingsources, *ipnet)
|
||||
c.tun.log.Infoln("Added CKR source subnet", cidr)
|
||||
return nil
|
||||
}
|
||||
|
||||
// Adds a destination route for the given CIDR to be tunnelled to the node
|
||||
// with the given BoxPubKey.
|
||||
func (c *cryptokey) addRoute(cidr string, dest string) error {
|
||||
// Is the CIDR we've been given valid?
|
||||
ipaddr, ipnet, err := net.ParseCIDR(cidr)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// Get the prefix length and size
|
||||
_, prefixsize := ipnet.Mask.Size()
|
||||
|
||||
// Build our references to the routing table and cache
|
||||
var routingtable *[]cryptokey_route
|
||||
var routingcache *map[address.Address]cryptokey_route
|
||||
|
||||
// Check if the prefix is IPv4 or IPv6
|
||||
if prefixsize == net.IPv6len*8 {
|
||||
routingtable = &c.ipv6routes
|
||||
routingcache = &c.ipv6cache
|
||||
} else if prefixsize == net.IPv4len*8 {
|
||||
routingtable = &c.ipv4routes
|
||||
routingcache = &c.ipv4cache
|
||||
} else {
|
||||
return errors.New("Unexpected prefix size")
|
||||
}
|
||||
|
||||
// Is the route an Yggdrasil destination?
|
||||
var addr address.Address
|
||||
var snet address.Subnet
|
||||
copy(addr[:], ipaddr)
|
||||
copy(snet[:], ipnet.IP)
|
||||
if addr.IsValid() || snet.IsValid() {
|
||||
return errors.New("Can't specify Yggdrasil destination as crypto-key route")
|
||||
}
|
||||
// Do we already have a route for this subnet?
|
||||
for _, route := range *routingtable {
|
||||
if route.subnet.String() == ipnet.String() {
|
||||
return errors.New(fmt.Sprintf("Route already exists for %s", cidr))
|
||||
}
|
||||
}
|
||||
// Decode the public key
|
||||
if bpk, err := hex.DecodeString(dest); err != nil {
|
||||
return err
|
||||
} else if len(bpk) != crypto.BoxPubKeyLen {
|
||||
return errors.New(fmt.Sprintf("Incorrect key length for %s", dest))
|
||||
} else {
|
||||
// Add the new crypto-key route
|
||||
var key crypto.BoxPubKey
|
||||
copy(key[:], bpk)
|
||||
*routingtable = append(*routingtable, cryptokey_route{
|
||||
subnet: *ipnet,
|
||||
destination: key,
|
||||
})
|
||||
|
||||
// Sort so most specific routes are first
|
||||
sort.Slice(*routingtable, func(i, j int) bool {
|
||||
im, _ := (*routingtable)[i].subnet.Mask.Size()
|
||||
jm, _ := (*routingtable)[j].subnet.Mask.Size()
|
||||
return im > jm
|
||||
})
|
||||
|
||||
// Clear the cache as this route might change future routing
|
||||
// Setting an empty slice keeps the memory whereas nil invokes GC
|
||||
for k := range *routingcache {
|
||||
delete(*routingcache, k)
|
||||
}
|
||||
|
||||
c.tun.log.Infoln("Added CKR destination subnet", cidr)
|
||||
return nil
|
||||
}
|
||||
}
|
||||
|
||||
// Looks up the most specific route for the given address (with the address
|
||||
// length specified in bytes) from the crypto-key routing table. An error is
|
||||
// returned if the address is not suitable or no route was found.
|
||||
func (c *cryptokey) getPublicKeyForAddress(addr address.Address, addrlen int) (crypto.BoxPubKey, error) {
|
||||
// Check if the address is a valid Yggdrasil address - if so it
|
||||
// is exempt from all CKR checking
|
||||
if addr.IsValid() {
|
||||
return crypto.BoxPubKey{}, errors.New("Cannot look up CKR for Yggdrasil addresses")
|
||||
}
|
||||
|
||||
// Build our references to the routing table and cache
|
||||
var routingtable *[]cryptokey_route
|
||||
var routingcache *map[address.Address]cryptokey_route
|
||||
|
||||
// Check if the prefix is IPv4 or IPv6
|
||||
if addrlen == net.IPv6len {
|
||||
routingtable = &c.ipv6routes
|
||||
routingcache = &c.ipv6cache
|
||||
} else if addrlen == net.IPv4len {
|
||||
routingtable = &c.ipv4routes
|
||||
routingcache = &c.ipv4cache
|
||||
} else {
|
||||
return crypto.BoxPubKey{}, errors.New("Unexpected prefix size")
|
||||
}
|
||||
|
||||
// Check if there's a cache entry for this addr
|
||||
if route, ok := (*routingcache)[addr]; ok {
|
||||
return route.destination, nil
|
||||
}
|
||||
|
||||
// No cache was found - start by converting the address into a net.IP
|
||||
ip := make(net.IP, addrlen)
|
||||
copy(ip[:addrlen], addr[:])
|
||||
|
||||
// Check if we have a route. At this point c.ipv6routes should be
|
||||
// pre-sorted so that the most specific routes are first
|
||||
for _, route := range *routingtable {
|
||||
// Does this subnet match the given IP?
|
||||
if route.subnet.Contains(ip) {
|
||||
// Check if the routing cache is above a certain size, if it is evict
|
||||
// a random entry so we can make room for this one. We take advantage
|
||||
// of the fact that the iteration order is random here
|
||||
for k := range *routingcache {
|
||||
if len(*routingcache) < 1024 {
|
||||
break
|
||||
}
|
||||
delete(*routingcache, k)
|
||||
}
|
||||
|
||||
// Cache the entry for future packets to get a faster lookup
|
||||
(*routingcache)[addr] = route
|
||||
|
||||
// Return the boxPubKey
|
||||
return route.destination, nil
|
||||
}
|
||||
}
|
||||
|
||||
// No route was found if we got to this point
|
||||
return crypto.BoxPubKey{}, errors.New(fmt.Sprintf("No route to %s", ip.String()))
|
||||
}
|
||||
|
||||
// Removes a source subnet, which allows traffic with these source addresses to
|
||||
// be tunnelled using crypto-key routing.
|
||||
func (c *cryptokey) removeSourceSubnet(cidr string) error {
|
||||
// Is the CIDR we've been given valid?
|
||||
_, ipnet, err := net.ParseCIDR(cidr)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// Get the prefix length and size
|
||||
_, prefixsize := ipnet.Mask.Size()
|
||||
|
||||
// Build our references to the routing sources
|
||||
var routingsources *[]net.IPNet
|
||||
|
||||
// Check if the prefix is IPv4 or IPv6
|
||||
if prefixsize == net.IPv6len*8 {
|
||||
routingsources = &c.ipv6sources
|
||||
} else if prefixsize == net.IPv4len*8 {
|
||||
routingsources = &c.ipv4sources
|
||||
} else {
|
||||
return errors.New("Unexpected prefix size")
|
||||
}
|
||||
|
||||
// Check if we already have this CIDR
|
||||
for idx, subnet := range *routingsources {
|
||||
if subnet.String() == ipnet.String() {
|
||||
*routingsources = append((*routingsources)[:idx], (*routingsources)[idx+1:]...)
|
||||
c.tun.log.Infoln("Removed CKR source subnet", cidr)
|
||||
return nil
|
||||
}
|
||||
}
|
||||
return errors.New("Source subnet not found")
|
||||
}
|
||||
|
||||
// Removes a destination route for the given CIDR to be tunnelled to the node
|
||||
// with the given BoxPubKey.
|
||||
func (c *cryptokey) removeRoute(cidr string, dest string) error {
|
||||
// Is the CIDR we've been given valid?
|
||||
_, ipnet, err := net.ParseCIDR(cidr)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// Get the prefix length and size
|
||||
_, prefixsize := ipnet.Mask.Size()
|
||||
|
||||
// Build our references to the routing table and cache
|
||||
var routingtable *[]cryptokey_route
|
||||
var routingcache *map[address.Address]cryptokey_route
|
||||
|
||||
// Check if the prefix is IPv4 or IPv6
|
||||
if prefixsize == net.IPv6len*8 {
|
||||
routingtable = &c.ipv6routes
|
||||
routingcache = &c.ipv6cache
|
||||
} else if prefixsize == net.IPv4len*8 {
|
||||
routingtable = &c.ipv4routes
|
||||
routingcache = &c.ipv4cache
|
||||
} else {
|
||||
return errors.New("Unexpected prefix size")
|
||||
}
|
||||
|
||||
// Decode the public key
|
||||
bpk, err := hex.DecodeString(dest)
|
||||
if err != nil {
|
||||
return err
|
||||
} else if len(bpk) != crypto.BoxPubKeyLen {
|
||||
return errors.New(fmt.Sprintf("Incorrect key length for %s", dest))
|
||||
}
|
||||
netStr := ipnet.String()
|
||||
|
||||
for idx, route := range *routingtable {
|
||||
if bytes.Equal(route.destination[:], bpk) && route.subnet.String() == netStr {
|
||||
*routingtable = append((*routingtable)[:idx], (*routingtable)[idx+1:]...)
|
||||
for k := range *routingcache {
|
||||
delete(*routingcache, k)
|
||||
}
|
||||
c.tun.log.Infoln("Removed CKR destination subnet %s via %s\n", cidr, dest)
|
||||
return nil
|
||||
}
|
||||
}
|
||||
return errors.New(fmt.Sprintf("Route does not exists for %s", cidr))
|
||||
}
|
||||
|
|
@ -178,10 +178,29 @@ func (tun *TunAdapter) reader() error {
|
|||
// Unknown address length or protocol, so drop the packet and ignore it
|
||||
continue
|
||||
}
|
||||
if !dstAddr.IsValid() && !dstSnet.IsValid() {
|
||||
// For now don't deal with any non-Yggdrasil ranges
|
||||
if !tun.ckr.isValidSource(srcAddr, addrlen) {
|
||||
// The packet had a source address that doesn't belong to us or our
|
||||
// configured crypto-key routing source subnets
|
||||
continue
|
||||
}
|
||||
if !dstAddr.IsValid() && !dstSnet.IsValid() {
|
||||
if key, err := tun.ckr.getPublicKeyForAddress(dstAddr, addrlen); err == nil {
|
||||
// A public key was found, get the node ID for the search
|
||||
dstNodeID = crypto.GetNodeID(&key)
|
||||
// Do a quick check to ensure that the node ID refers to a vaild
|
||||
// Yggdrasil address or subnet - this might be superfluous
|
||||
addr := *address.AddrForNodeID(dstNodeID)
|
||||
copy(dstAddr[:], addr[:])
|
||||
copy(dstSnet[:], addr[:])
|
||||
// Are we certain we looked up a valid node?
|
||||
if !dstAddr.IsValid() && !dstSnet.IsValid() {
|
||||
continue
|
||||
}
|
||||
} else {
|
||||
// No public key was found in the CKR table so we've exhausted our options
|
||||
continue
|
||||
}
|
||||
}
|
||||
// Do we have an active connection for this node address?
|
||||
tun.mutex.RLock()
|
||||
session, isIn := tun.addrToConn[dstAddr]
|
||||
|
|
@ -231,32 +250,5 @@ func (tun *TunAdapter) reader() error {
|
|||
util.PutBytes(packet)
|
||||
}
|
||||
}
|
||||
|
||||
/*if !r.cryptokey.isValidSource(srcAddr, addrlen) {
|
||||
// The packet had a src address that doesn't belong to us or our
|
||||
// configured crypto-key routing src subnets
|
||||
return
|
||||
}
|
||||
if !dstAddr.IsValid() && !dstSnet.IsValid() {
|
||||
// The addresses didn't match valid Yggdrasil node addresses so let's see
|
||||
// whether it matches a crypto-key routing range instead
|
||||
if key, err := r.cryptokey.getPublicKeyForAddress(dstAddr, addrlen); err == nil {
|
||||
// A public key was found, get the node ID for the search
|
||||
dstPubKey = &key
|
||||
dstNodeID = crypto.GetNodeID(dstPubKey)
|
||||
// Do a quick check to ensure that the node ID refers to a vaild Yggdrasil
|
||||
// address or subnet - this might be superfluous
|
||||
addr := *address.AddrForNodeID(dstNodeID)
|
||||
copy(dstAddr[:], addr[:])
|
||||
copy(dstSnet[:], addr[:])
|
||||
if !dstAddr.IsValid() && !dstSnet.IsValid() {
|
||||
return
|
||||
}
|
||||
} else {
|
||||
// No public key was found in the CKR table so we've exhausted our options
|
||||
return
|
||||
}
|
||||
}*/
|
||||
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -41,6 +41,7 @@ type TunAdapter struct {
|
|||
dialer *yggdrasil.Dialer
|
||||
addr address.Address
|
||||
subnet address.Subnet
|
||||
ckr cryptokey
|
||||
icmpv6 ICMPv6
|
||||
mtu int
|
||||
iface *water.Interface
|
||||
|
|
@ -117,8 +118,8 @@ func (tun *TunAdapter) Init(config *config.NodeState, log *log.Logger, listener
|
|||
// Start the setup process for the TUN/TAP adapter. If successful, starts the
|
||||
// read/write goroutines to handle packets on that interface.
|
||||
func (tun *TunAdapter) Start() error {
|
||||
tun.config.Mutex.Lock()
|
||||
defer tun.config.Mutex.Unlock()
|
||||
tun.config.Mutex.RLock()
|
||||
defer tun.config.Mutex.RUnlock()
|
||||
if tun.config == nil || tun.listener == nil || tun.dialer == nil {
|
||||
return errors.New("No configuration available to TUN/TAP")
|
||||
}
|
||||
|
|
@ -173,6 +174,7 @@ func (tun *TunAdapter) Start() error {
|
|||
go tun.reader()
|
||||
go tun.writer()
|
||||
tun.icmpv6.Init(tun)
|
||||
tun.ckr.init(tun)
|
||||
return nil
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue