src/yggdrasil/tcpip.go

   1 //go:build !noyggdrasil
   2 // +build !noyggdrasil
   3
   4 /*
   5 NNCP -- Node to Node copy, utilities for store-and-forward data exchange
   6 Copyright (C) 2016-2022 Sergey Matveev <stargrave@stargrave.org>
   7
   8 This program is free software: you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation, version 3 of the License.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19
  20 Code below is heavily based on Wireguard's MIT licenced
  21 golang.zx2c4.com/wireguard/tun/netstack.
  22 */
  23
  24 package yggdrasil
  25
  26 import (
  27         "fmt"
  28         "log"
  29         "net"
  30
  31         iwt "github.com/Arceliar/ironwood/types"
  32         yaddr "github.com/yggdrasil-network/yggdrasil-go/src/address"
  33         "golang.org/x/crypto/ed25519"
  34         "gvisor.dev/gvisor/pkg/bufferv2"
  35         "gvisor.dev/gvisor/pkg/tcpip"
  36         "gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
  37         "gvisor.dev/gvisor/pkg/tcpip/header"
  38         "gvisor.dev/gvisor/pkg/tcpip/network/ipv6"
  39         "gvisor.dev/gvisor/pkg/tcpip/stack"
  40         "gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
  41 )
  42
  43 const IPv6HdrSize = 40
  44
  45 type TCPIPEndpoint struct {
  46         mtu      uint32
  47         s        *stack.Stack
  48         pc       net.PacketConn
  49         d        stack.NetworkDispatcher
  50         readBuf  []byte
  51         writeBuf []byte
  52         ip       yaddr.Address
  53         ipToAddr map[yaddr.Address]net.Addr
  54         pubToIP  map[[ed25519.PublicKeySize]byte]yaddr.Address
  55 }
  56
  57 func (e *TCPIPEndpoint) Attach(dispatcher stack.NetworkDispatcher) { e.d = dispatcher }
  58
  59 func (e *TCPIPEndpoint) IsAttached() bool { return e.d != nil }
  60
  61 func (e *TCPIPEndpoint) MTU() uint32 { return e.mtu }
  62
  63 func (*TCPIPEndpoint) Capabilities() stack.LinkEndpointCapabilities { return stack.CapabilityNone }
  64
  65 func (*TCPIPEndpoint) MaxHeaderLength() uint16 { return 0 }
  66
  67 func (*TCPIPEndpoint) LinkAddress() tcpip.LinkAddress { return "" }
  68
  69 func (*TCPIPEndpoint) Wait() {}
  70
  71 func (e *TCPIPEndpoint) WritePacket(pkt stack.PacketBufferPtr) tcpip.Error {
  72         v := pkt.ToView()
  73         n, err := v.Read(e.writeBuf)
  74         if err != nil {
  75                 log.Println(err)
  76                 return &tcpip.ErrAborted{}
  77         }
  78         copy(e.ip[:], e.writeBuf[IPv6HdrSize-len(e.ip):IPv6HdrSize])
  79         addr, ok := e.ipToAddr[e.ip]
  80         if !ok {
  81                 log.Println("no address found:", e.ip)
  82                 return nil
  83         }
  84         _, err = e.pc.WriteTo(e.writeBuf[:n], addr)
  85         if err != nil {
  86                 log.Println(err)
  87                 return &tcpip.ErrAborted{}
  88         }
  89         return nil
  90 }
  91
  92 func (e *TCPIPEndpoint) WritePackets(pbs stack.PacketBufferList) (int, tcpip.Error) {
  93         for i, pb := range pbs.AsSlice() {
  94                 err := e.WritePacket(pb)
  95                 if err != nil {
  96                         return i + 1, err
  97                 }
  98         }
  99         return len(pbs.AsSlice()), nil
 100 }
 101
 102 func (*TCPIPEndpoint) ARPHardwareType() header.ARPHardwareType { return header.ARPHardwareNone }
 103
 104 func (e *TCPIPEndpoint) AddHeader(stack.PacketBufferPtr) {}
 105
 106 func convertToFullAddr(ip net.IP, port int) (tcpip.FullAddress, tcpip.NetworkProtocolNumber) {
 107         return tcpip.FullAddress{
 108                 NIC:  1,
 109                 Addr: tcpip.Address(ip),
 110                 Port: uint16(port),
 111         }, ipv6.ProtocolNumber
 112 }
 113
 114 func (e *TCPIPEndpoint) DialTCP(addr *net.TCPAddr) (*gonet.TCPConn, error) {
 115         if addr == nil {
 116                 panic("not implemented")
 117         }
 118         fa, pn := convertToFullAddr(addr.IP, addr.Port)
 119         return gonet.DialTCP(e.s, fa, pn)
 120 }
 121
 122 func (e *TCPIPEndpoint) ListenTCP(addr *net.TCPAddr) (*gonet.TCPListener, error) {
 123         if addr == nil {
 124                 panic("not implemented")
 125         }
 126         fa, pn := convertToFullAddr(addr.IP, addr.Port)
 127         return gonet.ListenTCP(e.s, fa, pn)
 128 }
 129
 130 func (e *TCPIPEndpoint) Close() error {
 131         e.s.RemoveNIC(1)
 132         return nil
 133 }
 134
 135 func NewTCPIPEndpoint(
 136         pc net.PacketConn,
 137         ipOur net.IP,
 138         mtu uint32,
 139 ) (*TCPIPEndpoint, error) {
 140         s := stack.New(stack.Options{
 141                 NetworkProtocols:   []stack.NetworkProtocolFactory{ipv6.NewProtocol},
 142                 TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol},
 143                 HandleLocal:        true,
 144         })
 145         e := TCPIPEndpoint{
 146                 mtu:      mtu,
 147                 s:        s,
 148                 pc:       pc,
 149                 readBuf:  make([]byte, 1<<16),
 150                 writeBuf: make([]byte, 1<<16),
 151                 ipToAddr: make(map[yaddr.Address]net.Addr),
 152                 pubToIP:  make(map[[ed25519.PublicKeySize]byte]yaddr.Address),
 153         }
 154         if err := s.CreateNIC(1, &e); err != nil {
 155                 return nil, fmt.Errorf("%+v", err)
 156         }
 157         protoAddr := tcpip.ProtocolAddress{
 158                 Protocol:          ipv6.ProtocolNumber,
 159                 AddressWithPrefix: tcpip.Address(ipOur).WithPrefix(),
 160         }
 161         if err := s.AddProtocolAddress(1, protoAddr, stack.AddressProperties{}); err != nil {
 162                 return nil, fmt.Errorf("%+v", err)
 163         }
 164         s.AddRoute(tcpip.Route{Destination: header.IPv6EmptySubnet, NIC: 1})
 165         go func() {
 166                 var n int
 167                 var from net.Addr
 168                 var err error
 169                 var pub [ed25519.PublicKeySize]byte
 170                 for {
 171                         n, from, err = pc.ReadFrom(e.readBuf)
 172                         if err != nil {
 173                                 log.Println(err)
 174                                 break
 175                         }
 176                         copy(pub[:], from.(iwt.Addr))
 177                         ip, ok := e.pubToIP[pub]
 178                         if !ok {
 179                                 copy(ip[:], yaddr.AddrForKey(ed25519.PublicKey(pub[:]))[:])
 180                                 e.pubToIP[pub] = ip
 181                                 e.ipToAddr[ip] = from
 182                         }
 183                         pkb := stack.NewPacketBuffer(stack.PacketBufferOptions{
 184                                 Payload: bufferv2.MakeWithData(e.readBuf[:n]),
 185                         })
 186                         e.d.DeliverNetworkPacket(ipv6.ProtocolNumber, pkb)
 187                 }
 188         }()
 189         return &e, nil
 190 }