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mirror of https://github.com/cwinfo/yggdrasil-go.git synced 2024-12-23 12:15:39 +00:00

Try using separate workers for each TUN/TAP connection (sometimes produces duplicate packets when communicating with both the node address and a subnet address, sometimes also can't Ctrl-C to quit)

This commit is contained in:
Neil Alexander 2019-04-28 17:14:09 +01:00
parent 6469e39ff1
commit 5f66c4c95c
No known key found for this signature in database
GPG Key ID: A02A2019A2BB0944
3 changed files with 376 additions and 474 deletions

75
src/tuntap/conn.go Normal file
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@ -0,0 +1,75 @@
package tuntap
import (
"errors"
"github.com/yggdrasil-network/yggdrasil-go/src/yggdrasil"
)
type tunConn struct {
tun *TunAdapter
conn *yggdrasil.Conn
send chan []byte
stop chan interface{}
}
func (s *tunConn) close() {
close(s.stop)
}
func (s *tunConn) reader() error {
select {
case _, ok := <-s.stop:
if !ok {
return errors.New("session was already closed")
}
default:
}
var n int
var err error
read := make(chan bool)
b := make([]byte, 65535)
for {
go func() {
if n, err = s.conn.Read(b); err != nil {
s.tun.log.Errorln(s.conn.String(), "TUN/TAP conn read error:", err)
return
}
read <- true
}()
select {
case <-read:
if n > 0 {
s.tun.send <- b[:n]
}
case <-s.stop:
s.tun.log.Debugln("Stopping conn reader for", s)
return nil
}
}
}
func (s *tunConn) writer() error {
select {
case _, ok := <-s.stop:
if !ok {
return errors.New("session was already closed")
}
default:
}
for {
select {
case <-s.stop:
s.tun.log.Debugln("Stopping conn writer for", s)
return nil
case b, ok := <-s.send:
if !ok {
return errors.New("send closed")
}
if _, err := s.conn.Write(b); err != nil {
s.tun.log.Errorln(s.conn.String(), "TUN/TAP conn write error:", err)
continue
}
}
}
}

255
src/tuntap/iface.go Normal file
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@ -0,0 +1,255 @@
package tuntap
import (
"bytes"
"errors"
"time"
"github.com/songgao/packets/ethernet"
"github.com/yggdrasil-network/yggdrasil-go/src/address"
"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
"github.com/yggdrasil-network/yggdrasil-go/src/util"
)
func (tun *TunAdapter) writer() error {
var w int
var err error
for {
b := <-tun.send
n := len(b)
if n == 0 {
continue
}
if tun.iface.IsTAP() {
var dstAddr address.Address
if b[0]&0xf0 == 0x60 {
if len(b) < 40 {
//panic("Tried to send a packet shorter than an IPv6 header...")
util.PutBytes(b)
continue
}
copy(dstAddr[:16], b[24:])
} else if b[0]&0xf0 == 0x40 {
if len(b) < 20 {
//panic("Tried to send a packet shorter than an IPv4 header...")
util.PutBytes(b)
continue
}
copy(dstAddr[:4], b[16:])
} else {
return errors.New("Invalid address family")
}
sendndp := func(dstAddr address.Address) {
neigh, known := tun.icmpv6.peermacs[dstAddr]
known = known && (time.Since(neigh.lastsolicitation).Seconds() < 30)
if !known {
request, err := tun.icmpv6.CreateNDPL2(dstAddr)
if err != nil {
panic(err)
}
if _, err := tun.iface.Write(request); err != nil {
panic(err)
}
tun.icmpv6.peermacs[dstAddr] = neighbor{
lastsolicitation: time.Now(),
}
}
}
var peermac macAddress
var peerknown bool
if b[0]&0xf0 == 0x40 {
dstAddr = tun.addr
} else if b[0]&0xf0 == 0x60 {
if !bytes.Equal(tun.addr[:16], dstAddr[:16]) && !bytes.Equal(tun.subnet[:8], dstAddr[:8]) {
dstAddr = tun.addr
}
}
if neighbor, ok := tun.icmpv6.peermacs[dstAddr]; ok && neighbor.learned {
peermac = neighbor.mac
peerknown = true
} else if neighbor, ok := tun.icmpv6.peermacs[tun.addr]; ok && neighbor.learned {
peermac = neighbor.mac
peerknown = true
sendndp(dstAddr)
} else {
sendndp(tun.addr)
}
if peerknown {
var proto ethernet.Ethertype
switch {
case b[0]&0xf0 == 0x60:
proto = ethernet.IPv6
case b[0]&0xf0 == 0x40:
proto = ethernet.IPv4
}
var frame ethernet.Frame
frame.Prepare(
peermac[:6], // Destination MAC address
tun.icmpv6.mymac[:6], // Source MAC address
ethernet.NotTagged, // VLAN tagging
proto, // Ethertype
len(b)) // Payload length
copy(frame[tun_ETHER_HEADER_LENGTH:], b[:n])
n += tun_ETHER_HEADER_LENGTH
w, err = tun.iface.Write(frame[:n])
}
} else {
w, err = tun.iface.Write(b[:n])
}
if err != nil {
tun.log.Errorln("TUN/TAP iface write error:", err)
continue
}
if w != n {
tun.log.Errorln("TUN/TAP iface write mismatch:", w, "bytes written vs", n, "bytes given")
continue
}
}
}
func (tun *TunAdapter) reader() error {
bs := make([]byte, 65535)
for {
// Wait for a packet to be delivered to us through the TUN/TAP adapter
n, err := tun.iface.Read(bs)
if err != nil {
panic(err)
}
if n == 0 {
continue
}
// If it's a TAP adapter, update the buffer slice so that we no longer
// include the ethernet headers
offset := 0
if tun.iface.IsTAP() {
// Set our offset to beyond the ethernet headers
offset = tun_ETHER_HEADER_LENGTH
// If we detect an ICMP packet then hand it to the ICMPv6 module
if bs[offset+6] == 58 {
// Found an ICMPv6 packet
b := make([]byte, n)
copy(b, bs)
go tun.icmpv6.ParsePacket(b)
}
// Then offset the buffer so that we can now just treat it as an IP
// packet from now on
bs = bs[offset:]
}
// From the IP header, work out what our source and destination addresses
// and node IDs are. We will need these in order to work out where to send
// the packet
var srcAddr address.Address
var dstAddr address.Address
var dstNodeID *crypto.NodeID
var dstNodeIDMask *crypto.NodeID
var dstSnet address.Subnet
var addrlen int
// Check the IP protocol - if it doesn't match then we drop the packet and
// do nothing with it
if bs[0]&0xf0 == 0x60 {
// Check if we have a fully-sized IPv6 header
if len(bs) < 40 {
continue
}
// Check the packet size
if n != 256*int(bs[4])+int(bs[5])+offset+tun_IPv6_HEADER_LENGTH {
continue
}
// IPv6 address
addrlen = 16
copy(srcAddr[:addrlen], bs[8:])
copy(dstAddr[:addrlen], bs[24:])
copy(dstSnet[:addrlen/2], bs[24:])
} else if bs[0]&0xf0 == 0x40 {
// Check if we have a fully-sized IPv4 header
if len(bs) < 20 {
continue
}
// Check the packet size
if n != 256*int(bs[2])+int(bs[3])+offset {
continue
}
// IPv4 address
addrlen = 4
copy(srcAddr[:addrlen], bs[12:])
copy(dstAddr[:addrlen], bs[16:])
} else {
// 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
continue
}
// Do we have an active connection for this node address?
tun.mutex.RLock()
session, isIn := tun.addrToConn[dstAddr]
if !isIn || session == nil {
session, isIn = tun.subnetToConn[dstSnet]
if !isIn || session == nil {
// Neither an address nor a subnet mapping matched, therefore populate
// the node ID and mask to commence a search
dstNodeID, dstNodeIDMask = dstAddr.GetNodeIDandMask()
}
}
tun.mutex.RUnlock()
// If we don't have a connection then we should open one
if !isIn || session == nil {
// Check we haven't been given empty node ID, really this shouldn't ever
// happen but just to be sure...
if dstNodeID == nil || dstNodeIDMask == nil {
panic("Given empty dstNodeID and dstNodeIDMask - this shouldn't happen")
}
// Dial to the remote node
if conn, err := tun.dialer.DialByNodeIDandMask(dstNodeID, dstNodeIDMask); err == nil {
// We've been given a connection so prepare the session wrapper
if s, err := tun.wrap(conn); err != nil {
// Something went wrong when storing the connection, typically that
// something already exists for this address or subnet
tun.log.Debugln("TUN/TAP iface wrap:", err)
} else {
// Update our reference to the connection
session, isIn = s, true
}
} else {
// We weren't able to dial for some reason so there's no point in
// continuing this iteration - skip to the next one
continue
}
}
// If we have a connection now, try writing to it
if isIn && session != nil {
select {
case session.send <- bs[:n]:
default:
}
}
/*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
}
}*/
}
}

View File

@ -6,10 +6,9 @@ package tuntap
// TODO: Set MTU of session properly
// TODO: Reject packets that exceed session MTU with ICMPv6 for PMTU Discovery
// TODO: Connection timeouts (call Conn.Close() when we want to time out)
// TODO: Don't block in ifaceReader on writes that are pending searches
// TODO: Don't block in reader on writes that are pending searches
import (
"bytes"
"encoding/hex"
"errors"
"fmt"
@ -18,14 +17,12 @@ import (
"time"
"github.com/gologme/log"
"github.com/songgao/packets/ethernet"
"github.com/yggdrasil-network/water"
"github.com/yggdrasil-network/yggdrasil-go/src/address"
"github.com/yggdrasil-network/yggdrasil-go/src/config"
"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
"github.com/yggdrasil-network/yggdrasil-go/src/defaults"
"github.com/yggdrasil-network/yggdrasil-go/src/util"
"github.com/yggdrasil-network/yggdrasil-go/src/yggdrasil"
)
@ -47,9 +44,10 @@ type TunAdapter struct {
icmpv6 ICMPv6
mtu int
iface *water.Interface
mutex sync.RWMutex // Protects the below
addrToConn map[address.Address]*yggdrasil.Conn // Managed by connReader
subnetToConn map[address.Subnet]*yggdrasil.Conn // Managed by connReader
send chan []byte
mutex sync.RWMutex // Protects the below
addrToConn map[address.Address]*tunConn
subnetToConn map[address.Subnet]*tunConn
isOpen bool
}
@ -112,8 +110,8 @@ func (tun *TunAdapter) Init(config *config.NodeState, log *log.Logger, listener
tun.log = log
tun.listener = listener
tun.dialer = dialer
tun.addrToConn = make(map[address.Address]*yggdrasil.Conn)
tun.subnetToConn = make(map[address.Subnet]*yggdrasil.Conn)
tun.addrToConn = make(map[address.Address]*tunConn)
tun.subnetToConn = make(map[address.Subnet]*tunConn)
}
// Start the setup process for the TUN/TAP adapter. If successful, starts the
@ -148,6 +146,7 @@ func (tun *TunAdapter) Start() error {
}
tun.mutex.Lock()
tun.isOpen = true
tun.send = make(chan []byte, 32) // TODO: is this a sensible value?
tun.mutex.Unlock()
if iftapmode {
go func() {
@ -159,9 +158,7 @@ func (tun *TunAdapter) Start() error {
if err != nil {
panic(err)
}
if _, err := tun.iface.Write(request); err != nil {
panic(err)
}
tun.send <- request
time.Sleep(time.Second)
}
}()
@ -173,7 +170,8 @@ func (tun *TunAdapter) Start() error {
}
}()
go tun.handler()
go tun.ifaceReader()
go tun.reader()
go tun.writer()
tun.icmpv6.Init(tun)
return nil
}
@ -186,473 +184,47 @@ func (tun *TunAdapter) handler() error {
tun.log.Errorln("TUN/TAP connection accept error:", err)
return err
}
go tun.connReader(conn)
if _, err := tun.wrap(conn); err != nil {
// Something went wrong when storing the connection, typically that
// something already exists for this address or subnet
tun.log.Debugln("TUN/TAP handler wrap:", err)
}
}
}
func (tun *TunAdapter) connReader(conn *yggdrasil.Conn) error {
func (tun *TunAdapter) wrap(conn *yggdrasil.Conn) (c *tunConn, err error) {
// Prepare a session wrapper for the given connection
s := tunConn{
tun: tun,
conn: conn,
send: make(chan []byte, 32), // TODO: is this a sensible value?
stop: make(chan interface{}),
}
// Get the remote address and subnet of the other side
remoteNodeID := conn.RemoteAddr()
remoteAddr := address.AddrForNodeID(&remoteNodeID)
remoteSubnet := address.SubnetForNodeID(&remoteNodeID)
err := func() error {
tun.mutex.RLock()
defer tun.mutex.RUnlock()
if _, isIn := tun.addrToConn[*remoteAddr]; isIn {
return errors.New("duplicate connection for address " + net.IP(remoteAddr[:]).String())
}
if _, isIn := tun.subnetToConn[*remoteSubnet]; isIn {
return errors.New("duplicate connection for subnet " + net.IP(remoteSubnet[:]).String())
}
return nil
}()
if err != nil {
//return err
panic(err)
}
// Store the connection mapped to address and subnet
// Work out if this is already a destination we already know about
tun.mutex.Lock()
tun.addrToConn[*remoteAddr] = conn
tun.subnetToConn[*remoteSubnet] = conn
tun.mutex.Unlock()
// Make sure to clean those up later when the connection is closed
defer func() {
tun.mutex.Lock()
delete(tun.addrToConn, *remoteAddr)
delete(tun.subnetToConn, *remoteSubnet)
tun.mutex.Unlock()
}()
b := make([]byte, 65535)
for {
n, err := conn.Read(b)
if err != nil {
tun.log.Errorln(conn.String(), "TUN/TAP conn read error:", err)
continue
}
if n == 0 {
continue
}
var w int
if tun.iface.IsTAP() {
var dstAddr address.Address
if b[0]&0xf0 == 0x60 {
if len(b) < 40 {
//panic("Tried to send a packet shorter than an IPv6 header...")
util.PutBytes(b)
continue
}
copy(dstAddr[:16], b[24:])
} else if b[0]&0xf0 == 0x40 {
if len(b) < 20 {
//panic("Tried to send a packet shorter than an IPv4 header...")
util.PutBytes(b)
continue
}
copy(dstAddr[:4], b[16:])
} else {
return errors.New("Invalid address family")
}
sendndp := func(dstAddr address.Address) {
neigh, known := tun.icmpv6.peermacs[dstAddr]
known = known && (time.Since(neigh.lastsolicitation).Seconds() < 30)
if !known {
request, err := tun.icmpv6.CreateNDPL2(dstAddr)
if err != nil {
panic(err)
}
if _, err := tun.iface.Write(request); err != nil {
panic(err)
}
tun.icmpv6.peermacs[dstAddr] = neighbor{
lastsolicitation: time.Now(),
}
}
}
var peermac macAddress
var peerknown bool
if b[0]&0xf0 == 0x40 {
dstAddr = tun.addr
} else if b[0]&0xf0 == 0x60 {
if !bytes.Equal(tun.addr[:16], dstAddr[:16]) && !bytes.Equal(tun.subnet[:8], dstAddr[:8]) {
dstAddr = tun.addr
}
}
if neighbor, ok := tun.icmpv6.peermacs[dstAddr]; ok && neighbor.learned {
peermac = neighbor.mac
peerknown = true
} else if neighbor, ok := tun.icmpv6.peermacs[tun.addr]; ok && neighbor.learned {
peermac = neighbor.mac
peerknown = true
sendndp(dstAddr)
} else {
sendndp(tun.addr)
}
if peerknown {
var proto ethernet.Ethertype
switch {
case b[0]&0xf0 == 0x60:
proto = ethernet.IPv6
case b[0]&0xf0 == 0x40:
proto = ethernet.IPv4
}
var frame ethernet.Frame
frame.Prepare(
peermac[:6], // Destination MAC address
tun.icmpv6.mymac[:6], // Source MAC address
ethernet.NotTagged, // VLAN tagging
proto, // Ethertype
len(b)) // Payload length
copy(frame[tun_ETHER_HEADER_LENGTH:], b[:n])
n += tun_ETHER_HEADER_LENGTH
w, err = tun.iface.Write(frame[:n])
}
} else {
w, err = tun.iface.Write(b[:n])
}
if err != nil {
tun.log.Errorln(conn.String(), "TUN/TAP iface write error:", err)
continue
}
if w != n {
tun.log.Errorln(conn.String(), "TUN/TAP iface write mismatch:", w, "bytes written vs", n, "bytes given")
continue
}
defer tun.mutex.Unlock()
atc, aok := tun.addrToConn[*remoteAddr]
stc, sok := tun.subnetToConn[*remoteSubnet]
// If we know about a connection for this destination already then assume it
// is no longer valid and close it
if aok {
atc.close()
err = errors.New("replaced connection for address")
} else if sok {
stc.close()
err = errors.New("replaced connection for subnet")
}
// Save the session wrapper so that we can look it up quickly next time
// we receive a packet through the interface for this address
tun.addrToConn[*remoteAddr] = &s
tun.subnetToConn[*remoteSubnet] = &s
// Start the connection goroutines
go s.reader()
go s.writer()
// Return
return c, err
}
func (tun *TunAdapter) ifaceReader() error {
bs := make([]byte, 65535)
for {
// Wait for a packet to be delivered to us through the TUN/TAP adapter
n, err := tun.iface.Read(bs)
if err != nil {
continue
}
// If it's a TAP adapter, update the buffer slice so that we no longer
// include the ethernet headers
offset := 0
if tun.iface.IsTAP() {
// Set our offset to beyond the ethernet headers
offset = tun_ETHER_HEADER_LENGTH
// If we detect an ICMP packet then hand it to the ICMPv6 module
if bs[offset+6] == 58 {
// Found an ICMPv6 packet
b := make([]byte, n)
copy(b, bs)
go tun.icmpv6.ParsePacket(b)
}
// Then offset the buffer so that we can now just treat it as an IP
// packet from now on
bs = bs[offset:]
}
// From the IP header, work out what our source and destination addresses
// and node IDs are. We will need these in order to work out where to send
// the packet
var srcAddr address.Address
var dstAddr address.Address
var dstNodeID *crypto.NodeID
var dstNodeIDMask *crypto.NodeID
var dstSnet address.Subnet
var addrlen int
// Check the IP protocol - if it doesn't match then we drop the packet and
// do nothing with it
if bs[0]&0xf0 == 0x60 {
// Check if we have a fully-sized IPv6 header
if len(bs) < 40 {
continue
}
// Check the packet size
if n != 256*int(bs[4])+int(bs[5])+offset+tun_IPv6_HEADER_LENGTH {
continue
}
// IPv6 address
addrlen = 16
copy(srcAddr[:addrlen], bs[8:])
copy(dstAddr[:addrlen], bs[24:])
copy(dstSnet[:addrlen/2], bs[24:])
} else if bs[0]&0xf0 == 0x40 {
// Check if we have a fully-sized IPv4 header
if len(bs) < 20 {
continue
}
// Check the packet size
if n != 256*int(bs[2])+int(bs[3])+offset {
continue
}
// IPv4 address
addrlen = 4
copy(srcAddr[:addrlen], bs[12:])
copy(dstAddr[:addrlen], bs[16:])
} else {
// 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
continue
}
// Do we have an active connection for this node address?
tun.mutex.RLock()
conn, isIn := tun.addrToConn[dstAddr]
if !isIn || conn == nil {
conn, isIn = tun.subnetToConn[dstSnet]
if !isIn || conn == nil {
// Neither an address nor a subnet mapping matched, therefore populate
// the node ID and mask to commence a search
dstNodeID, dstNodeIDMask = dstAddr.GetNodeIDandMask()
}
}
tun.mutex.RUnlock()
// If we don't have a connection then we should open one
if !isIn || conn == nil {
// Check we haven't been given empty node ID, really this shouldn't ever
// happen but just to be sure...
if dstNodeID == nil || dstNodeIDMask == nil {
panic("Given empty dstNodeID and dstNodeIDMask - this shouldn't happen")
}
// Dial to the remote node
if c, err := tun.dialer.DialByNodeIDandMask(dstNodeID, dstNodeIDMask); err == nil {
// We've been given a connection so start the connection reader goroutine
go tun.connReader(c)
// Then update our reference to the connection
conn, isIn = c, true
} else {
// We weren't able to dial for some reason so there's no point in
// continuing this iteration - skip to the next one
continue
}
}
// If we have a connection now, try writing to it
if isIn && conn != nil {
// If we have an open connection, either because we already had one or
// because we opened one above, try writing the packet to it
w, err := conn.Write(bs[:n])
if err != nil {
tun.log.Errorln(conn.String(), "TUN/TAP conn write error:", err)
continue
}
if w != n {
tun.log.Errorln(conn.String(), "TUN/TAP conn write mismatch:", w, "bytes written vs", n, "bytes given")
continue
}
}
/*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
}
}*/
}
}
// Writes a packet to the TUN/TAP adapter. If the adapter is running in TAP
// mode then additional ethernet encapsulation is added for the benefit of the
// host operating system.
/*
func (tun *TunAdapter) write() error {
for {
select {
case reject := <-tun.Reject:
switch reject.Reason {
case yggdrasil.PacketTooBig:
if mtu, ok := reject.Detail.(int); ok {
// Create the Packet Too Big response
ptb := &icmp.PacketTooBig{
MTU: int(mtu),
Data: reject.Packet,
}
// Create the ICMPv6 response from it
icmpv6Buf, err := CreateICMPv6(
reject.Packet[8:24], reject.Packet[24:40],
ipv6.ICMPTypePacketTooBig, 0, ptb)
// Send the ICMPv6 response back to the TUN/TAP adapter
if err == nil {
tun.iface.Write(icmpv6Buf)
}
}
fallthrough
default:
continue
}
case data := <-tun.Recv:
if tun.iface == nil {
continue
}
if tun.iface.IsTAP() {
var dstAddr address.Address
if data[0]&0xf0 == 0x60 {
if len(data) < 40 {
//panic("Tried to send a packet shorter than an IPv6 header...")
util.PutBytes(data)
continue
}
copy(dstAddr[:16], data[24:])
} else if data[0]&0xf0 == 0x40 {
if len(data) < 20 {
//panic("Tried to send a packet shorter than an IPv4 header...")
util.PutBytes(data)
continue
}
copy(dstAddr[:4], data[16:])
} else {
return errors.New("Invalid address family")
}
sendndp := func(dstAddr address.Address) {
neigh, known := tun.icmpv6.peermacs[dstAddr]
known = known && (time.Since(neigh.lastsolicitation).Seconds() < 30)
if !known {
request, err := tun.icmpv6.CreateNDPL2(dstAddr)
if err != nil {
panic(err)
}
if _, err := tun.iface.Write(request); err != nil {
panic(err)
}
tun.icmpv6.peermacs[dstAddr] = neighbor{
lastsolicitation: time.Now(),
}
}
}
var peermac macAddress
var peerknown bool
if data[0]&0xf0 == 0x40 {
dstAddr = tun.addr
} else if data[0]&0xf0 == 0x60 {
if !bytes.Equal(tun.addr[:16], dstAddr[:16]) && !bytes.Equal(tun.subnet[:8], dstAddr[:8]) {
dstAddr = tun.addr
}
}
if neighbor, ok := tun.icmpv6.peermacs[dstAddr]; ok && neighbor.learned {
peermac = neighbor.mac
peerknown = true
} else if neighbor, ok := tun.icmpv6.peermacs[tun.addr]; ok && neighbor.learned {
peermac = neighbor.mac
peerknown = true
sendndp(dstAddr)
} else {
sendndp(tun.addr)
}
if peerknown {
var proto ethernet.Ethertype
switch {
case data[0]&0xf0 == 0x60:
proto = ethernet.IPv6
case data[0]&0xf0 == 0x40:
proto = ethernet.IPv4
}
var frame ethernet.Frame
frame.Prepare(
peermac[:6], // Destination MAC address
tun.icmpv6.mymac[:6], // Source MAC address
ethernet.NotTagged, // VLAN tagging
proto, // Ethertype
len(data)) // Payload length
copy(frame[tun_ETHER_HEADER_LENGTH:], data[:])
if _, err := tun.iface.Write(frame); err != nil {
tun.mutex.RLock()
open := tun.isOpen
tun.mutex.RUnlock()
if !open {
return nil
} else {
panic(err)
}
}
}
} else {
if _, err := tun.iface.Write(data); err != nil {
tun.mutex.RLock()
open := tun.isOpen
tun.mutex.RUnlock()
if !open {
return nil
} else {
panic(err)
}
}
}
util.PutBytes(data)
}
}
}
// Reads any packets that are waiting on the TUN/TAP adapter. If the adapter
// is running in TAP mode then the ethernet headers will automatically be
// processed and stripped if necessary. If an ICMPv6 packet is found, then
// the relevant helper functions in icmpv6.go are called.
func (tun *TunAdapter) read() error {
mtu := tun.mtu
if tun.iface.IsTAP() {
mtu += tun_ETHER_HEADER_LENGTH
}
buf := make([]byte, mtu)
for {
n, err := tun.iface.Read(buf)
if err != nil {
tun.mutex.RLock()
open := tun.isOpen
tun.mutex.RUnlock()
if !open {
return nil
} else {
return err
}
}
o := 0
if tun.iface.IsTAP() {
o = tun_ETHER_HEADER_LENGTH
}
switch {
case buf[o]&0xf0 == 0x60 && n == 256*int(buf[o+4])+int(buf[o+5])+tun_IPv6_HEADER_LENGTH+o:
case buf[o]&0xf0 == 0x40 && n == 256*int(buf[o+2])+int(buf[o+3])+o:
default:
continue
}
if buf[o+6] == 58 {
if tun.iface.IsTAP() {
// Found an ICMPv6 packet
b := make([]byte, n)
copy(b, buf)
go tun.icmpv6.ParsePacket(b)
}
}
packet := append(util.GetBytes(), buf[o:n]...)
tun.Send <- packet
}
}
// Closes the TUN/TAP adapter. This is only usually called when the Yggdrasil
// process stops. Typically this operation will happen quickly, but on macOS
// it can block until a read operation is completed.
func (tun *TunAdapter) Close() error {
tun.mutex.Lock()
tun.isOpen = false
tun.mutex.Unlock()
if tun.iface == nil {
return nil
}
return tun.iface.Close()
}
*/