cwinfo/yggdrasil-go
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move ckr checks into the tunConn code

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This commit is contained in:
Arceliar
2019-08-20 18:10:08 -05:00
parent b79829c43b
commit 4156aa3003
3 changed files with 123 additions and 118 deletions
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128
src/tuntap/conn.go
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@ -6,6 +6,7 @@ import (
"time"
"github.com/yggdrasil-network/yggdrasil-go/src/address"
"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
"github.com/yggdrasil-network/yggdrasil-go/src/util"
"github.com/yggdrasil-network/yggdrasil-go/src/yggdrasil"
"golang.org/x/net/icmp"
@ -71,16 +72,62 @@ func (s *tunConn) reader() (err error) {
return e
}
} else if len(bs) > 0 {
if bs[0]&0xf0 == 0x60 {
switch {
case bs[8] == 0x02 && !bytes.Equal(s.addr[:16], bs[8:24]): // source
case bs[8] == 0x03 && !bytes.Equal(s.snet[:8], bs[8:16]): // source
case bs[24] == 0x02 && !bytes.Equal(s.tun.addr[:16], bs[24:40]): // destination
case bs[24] == 0x03 && !bytes.Equal(s.tun.subnet[:8], bs[24:32]): // destination
util.PutBytes(bs)
continue
default:
ipv4 := len(bs) > 20 && bs[0]&0xf0 == 0x40
ipv6 := len(bs) > 40 && bs[0]&0xf0 == 0x60
isCGA := true
// Check source addresses
switch {
case ipv6 && bs[8] == 0x02 && bytes.Equal(s.addr[:16], bs[8:24]): // source
case ipv6 && bs[8] == 0x03 && bytes.Equal(s.snet[:8], bs[8:16]): // source
default:
isCGA = false
}
// Check destiantion addresses
switch {
case ipv6 && bs[24] == 0x02 && bytes.Equal(s.tun.addr[:16], bs[24:40]): // destination
case ipv6 && bs[24] == 0x03 && bytes.Equal(s.tun.subnet[:8], bs[24:32]): // destination
default:
isCGA = false
}
// Decide how to handle the packet
var skip bool
switch {
case isCGA: // Allowed
case s.tun.ckr.isEnabled() && (ipv4 || ipv6):
var srcAddr address.Address
var dstAddr address.Address
var addrlen int
if ipv4 {
copy(srcAddr[:], bs[12:16])
copy(dstAddr[:], bs[16:20])
addrlen = 4
}
if ipv6 {
copy(srcAddr[:], bs[8:24])
copy(dstAddr[:], bs[24:40])
addrlen = 16
}
if !s.tun.ckr.isValidLocalAddress(dstAddr, addrlen) {
// The destination address isn't in our CKR allowed range
skip = true
} else if key, err := s.tun.ckr.getPublicKeyForAddress(srcAddr, addrlen); err == nil {
srcNodeID := crypto.GetNodeID(&key)
if s.conn.RemoteAddr() == *srcNodeID {
// This is the one allowed CKR case, where source and destination addresses are both good
} else {
// The CKR key associated with this address doesn't match the sender's NodeID
skip = true
}
} else {
// We have no CKR route for this source address
skip = true
}
default:
skip = true
}
if skip {
util.PutBytes(bs)
continue
}
s.tun.send <- bs
s.stillAlive()
@ -108,15 +155,62 @@ func (s *tunConn) writer() error {
if !ok {
return errors.New("send closed")
}
if bs[0]&0xf0 == 0x60 {
switch {
case bs[8] == 0x02 && !bytes.Equal(s.tun.addr[:16], bs[8:24]): // source
case bs[8] == 0x03 && !bytes.Equal(s.tun.subnet[:8], bs[8:16]): // source
case bs[24] == 0x02 && !bytes.Equal(s.addr[:16], bs[24:40]): // destination
case bs[24] == 0x03 && !bytes.Equal(s.snet[:8], bs[24:32]): // destination
continue
default:
v4 := len(bs) > 20 && bs[0]&0xf0 == 0x40
v6 := len(bs) > 40 && bs[0]&0xf0 == 0x60
isCGA := true
// Check source addresses
switch {
case v6 && bs[8] == 0x02 && bytes.Equal(s.tun.addr[:16], bs[8:24]): // source
case v6 && bs[8] == 0x03 && bytes.Equal(s.tun.subnet[:8], bs[8:16]): // source
default:
isCGA = false
}
// Check destiantion addresses
switch {
case v6 && bs[24] == 0x02 && bytes.Equal(s.addr[:16], bs[24:40]): // destination
case v6 && bs[24] == 0x03 && bytes.Equal(s.snet[:8], bs[24:32]): // destination
default:
isCGA = false
}
// Decide how to handle the packet
var skip bool
switch {
case isCGA: // Allowed
case s.tun.ckr.isEnabled() && (v4 || v6):
var srcAddr address.Address
var dstAddr address.Address
var addrlen int
if v4 {
copy(srcAddr[:], bs[12:16])
copy(dstAddr[:], bs[16:20])
addrlen = 4
}
if v6 {
copy(srcAddr[:], bs[8:24])
copy(dstAddr[:], bs[24:40])
addrlen = 16
}
if !s.tun.ckr.isValidLocalAddress(srcAddr, addrlen) {
// The source address isn't in our CKR allowed range
skip = true
} else if key, err := s.tun.ckr.getPublicKeyForAddress(dstAddr, addrlen); err == nil {
dstNodeID := crypto.GetNodeID(&key)
if s.conn.RemoteAddr() == *dstNodeID {
// This is the one allowed CKR case, where source and destination addresses are both good
} else {
// The CKR key associated with this address doesn't match the sender's NodeID
skip = true
}
} else {
// We have no CKR route for this destination address... why do we have the packet in the first place?
skip = true
}
default:
skip = true
}
if skip {
util.PutBytes(bs)
continue
}
msg := yggdrasil.FlowKeyMessage{
FlowKey: util.GetFlowKey(bs),