Re-add ICMPv6 packet too big handling

This commit is contained in:
Neil Alexander 2019-05-29 20:16:17 +01:00
parent 3b6c726a3c
commit 0096d1ae3e
No known key found for this signature in database
GPG Key ID: A02A2019A2BB0944
2 changed files with 44 additions and 8 deletions

View File

@ -7,6 +7,8 @@ import (
"github.com/yggdrasil-network/yggdrasil-go/src/address"
"github.com/yggdrasil-network/yggdrasil-go/src/util"
"github.com/yggdrasil-network/yggdrasil-go/src/yggdrasil"
"golang.org/x/net/icmp"
"golang.org/x/net/ipv6"
)
type tunConn struct {
@ -97,7 +99,21 @@ func (s *tunConn) writer() error {
}
// TODO write timeout and close
if _, err := s.conn.Write(b); err != nil {
s.tun.log.Errorln(s.conn.String(), "TUN/TAP conn write error:", err)
e, eok := err.(yggdrasil.ConnError)
if !eok {
s.tun.log.Errorln(s.conn.String(), "TUN/TAP generic write error:", err)
} else if ispackettoobig, maxsize := e.PacketTooBig(); ispackettoobig {
// TODO: This currently isn't aware of IPv4 for CKR
ptb := &icmp.PacketTooBig{
MTU: int(maxsize),
Data: b[:900],
}
if packet, err := CreateICMPv6(b[8:24], b[24:40], ipv6.ICMPTypePacketTooBig, 0, ptb); err == nil {
s.tun.send <- packet
}
} else {
s.tun.log.Errorln(s.conn.String(), "TUN/TAP conn write error:", err)
}
}
util.PutBytes(b)
s.stillAlive()

View File

@ -11,21 +11,33 @@ import (
"github.com/yggdrasil-network/yggdrasil-go/src/util"
)
// Error implements the net.Error interface
// ConnError implements the net.Error interface
type ConnError struct {
error
timeout bool
temporary bool
maxsize int
}
// Timeout returns true if the error relates to a timeout condition on the
// connection.
func (e *ConnError) Timeout() bool {
return e.timeout
}
// Temporary return true if the error is temporary or false if it is a permanent
// error condition.
func (e *ConnError) Temporary() bool {
return e.temporary
}
// PacketTooBig returns in response to sending a packet that is too large, and
// if so, the maximum supported packet size that should be used for the
// connection.
func (e *ConnError) PacketTooBig() (bool, int) {
return e.maxsize > 0, e.maxsize
}
type Conn struct {
core *Core
nodeID *crypto.NodeID
@ -166,7 +178,7 @@ func (c *Conn) Read(b []byte) (int, error) {
select {
case <-c.searchwait:
case <-timer.C:
return 0, ConnError{errors.New("Timeout"), true, false}
return 0, ConnError{errors.New("timeout"), true, false, 0}
}
// Retrieve our session info again
c.mutex.RLock()
@ -182,7 +194,7 @@ func (c *Conn) Read(b []byte) (int, error) {
// Wait for some traffic to come through from the session
select {
case <-timer.C:
return 0, ConnError{errors.New("Timeout"), true, false}
return 0, ConnError{errors.New("timeout"), true, false, 0}
case p, ok := <-sinfo.recv:
// If the session is closed then do nothing
if !ok {
@ -222,7 +234,7 @@ func (c *Conn) Read(b []byte) (int, error) {
select { // Send to worker
case sinfo.worker <- workerFunc:
case <-timer.C:
return 0, ConnError{errors.New("Timeout"), true, false}
return 0, ConnError{errors.New("timeout"), true, false, 0}
}
<-done // Wait for the worker to finish, failing this can cause memory errors (util.[Get||Put]Bytes stuff)
// Something went wrong in the session worker so abort
@ -260,8 +272,14 @@ func (c *Conn) Write(b []byte) (bytesWritten int, err error) {
}
var packet []byte
done := make(chan struct{})
written := len(b)
workerFunc := func() {
defer close(done)
// Does the packet exceed the permitted size for the session?
if uint16(len(b)) > sinfo.getMTU() {
written, err = 0, ConnError{errors.New("packet too big"), true, false, int(sinfo.getMTU())}
return
}
// Encrypt the packet
payload, nonce := crypto.BoxSeal(&sinfo.sharedSesKey, b, &sinfo.myNonce)
defer util.PutBytes(payload)
@ -282,14 +300,16 @@ func (c *Conn) Write(b []byte) (bytesWritten int, err error) {
select { // Send to worker
case sinfo.worker <- workerFunc:
case <-timer.C:
return 0, ConnError{errors.New("Timeout"), true, false}
return 0, ConnError{errors.New("timeout"), true, false, 0}
}
// Wait for the worker to finish, otherwise there are memory errors ([Get||Put]Bytes stuff)
<-done
// Give the packet to the router
sinfo.core.router.out(packet)
if written > 0 {
sinfo.core.router.out(packet)
}
// Finally return the number of bytes we wrote
return len(b), nil
return written, err
}
func (c *Conn) Close() error {