allow for multiple traffic types inside the session at the tuntap level, only implement typeSessionTraffic for now

This commit is contained in:
Arceliar 2021-05-16 13:01:54 -05:00
parent dfca87ba80
commit 2c7b22db92
3 changed files with 38 additions and 10 deletions

View File

@ -50,6 +50,8 @@ func (tun *TunAdapter) read() {
if srcAddr != tun.addr && srcSubnet != tun.subnet { if srcAddr != tun.addr && srcSubnet != tun.subnet {
continue // Wrong soruce address continue // Wrong soruce address
} }
bs = buf[begin-1 : end]
bs[0] = typeSessionTraffic
if dstAddr.IsValid() { if dstAddr.IsValid() {
tun.store.sendToAddress(dstAddr, bs) tun.store.sendToAddress(dstAddr, bs)
} else if dstSubnet.IsValid() { } else if dstSubnet.IsValid() {
@ -61,12 +63,24 @@ func (tun *TunAdapter) read() {
func (tun *TunAdapter) write() { func (tun *TunAdapter) write() {
var buf [TUN_OFFSET_BYTES + 65535]byte var buf [TUN_OFFSET_BYTES + 65535]byte
for { for {
bs := buf[TUN_OFFSET_BYTES:] bs := buf[TUN_OFFSET_BYTES-1:]
n, from, err := tun.core.ReadFrom(bs) n, from, err := tun.core.ReadFrom(bs)
if err != nil { if err != nil {
return return
} }
bs = bs[:n] if n == 0 {
continue
}
switch bs[0] {
case typeSessionTraffic:
// This is what we want to handle here
default:
continue
}
bs = bs[1:n]
if len(bs) == 0 {
continue
}
if bs[0]&0xf0 != 0x60 { if bs[0]&0xf0 != 0x60 {
continue // not IPv6 continue // not IPv6
} }
@ -99,7 +113,7 @@ func (tun *TunAdapter) write() {
if srcAddr != info.address && srcSubnet != info.subnet { if srcAddr != info.address && srcSubnet != info.subnet {
continue // bad remote address/subnet continue // bad remote address/subnet
} }
bs = buf[:TUN_OFFSET_BYTES+n] bs = buf[:TUN_OFFSET_BYTES+len(bs)]
n, err = tun.iface.Write(bs, TUN_OFFSET_BYTES) n, err = tun.iface.Write(bs, TUN_OFFSET_BYTES)
if err != nil { if err != nil {
tun.Act(nil, func() { tun.Act(nil, func() {

View File

@ -150,8 +150,8 @@ func (tun *TunAdapter) _start() error {
return nil return nil
} }
mtu := current.IfMTU mtu := current.IfMTU
if tun.core.MTU() < uint64(mtu) { if tun.maxSessionMTU() < mtu {
mtu = MTU(tun.core.MTU()) mtu = tun.maxSessionMTU()
} }
if err := tun.setup(current.IfName, addr, mtu); err != nil { if err := tun.setup(current.IfName, addr, mtu); err != nil {
return err return err
@ -216,11 +216,6 @@ func (tun *TunAdapter) oobHandler(fromKey, toKey ed25519.PublicKey, data []byte)
} }
} }
const (
typeKeyLookup = 1
typeKeyResponse = 2
)
func (tun *TunAdapter) sendKeyLookup(partial ed25519.PublicKey) { func (tun *TunAdapter) sendKeyLookup(partial ed25519.PublicKey) {
sig := ed25519.Sign(tun.core.PrivateKey(), partial[:]) sig := ed25519.Sign(tun.core.PrivateKey(), partial[:])
bs := append([]byte{typeKeyLookup}, sig...) bs := append([]byte{typeKeyLookup}, sig...)
@ -232,3 +227,8 @@ func (tun *TunAdapter) sendKeyResponse(dest ed25519.PublicKey) {
bs := append([]byte{typeKeyResponse}, sig...) bs := append([]byte{typeKeyResponse}, sig...)
tun.core.SendOutOfBand(dest, bs) tun.core.SendOutOfBand(dest, bs)
} }
func (tun *TunAdapter) maxSessionMTU() MTU {
const sessionTypeOverhead = 1
return MTU(tun.core.MTU() - sessionTypeOverhead)
}

14
src/tuntap/types.go Normal file
View File

@ -0,0 +1,14 @@
package tuntap
// Out-of-band packet types
const (
typeKeyDummy = iota
typeKeyLookup
typeKeyResponse
)
// In-band packet types
const (
typeSessionDummy = iota
typeSessionTraffic
)