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.PacketBuffer) 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 (e *TCPIPEndpoint) WriteRawPacket(*stack.PacketBuffer) tcpip.Error {
 103         panic("not implemented")
 104 }
 105
 106 func (*TCPIPEndpoint) ARPHardwareType() header.ARPHardwareType { return header.ARPHardwareNone }
 107
 108 func (e *TCPIPEndpoint) AddHeader(*stack.PacketBuffer) {}
 109
 110 func convertToFullAddr(ip net.IP, port int) (tcpip.FullAddress, tcpip.NetworkProtocolNumber) {
 111         return tcpip.FullAddress{
 112                 NIC:  1,
 113                 Addr: tcpip.Address(ip),
 114                 Port: uint16(port),
 115         }, ipv6.ProtocolNumber
 116 }
 117
 118 func (e *TCPIPEndpoint) DialTCP(addr *net.TCPAddr) (*gonet.TCPConn, error) {
 119         if addr == nil {
 120                 panic("not implemented")
 121         }
 122         fa, pn := convertToFullAddr(addr.IP, addr.Port)
 123         return gonet.DialTCP(e.s, fa, pn)
 124 }
 125
 126 func (e *TCPIPEndpoint) ListenTCP(addr *net.TCPAddr) (*gonet.TCPListener, error) {
 127         if addr == nil {
 128                 panic("not implemented")
 129         }
 130         fa, pn := convertToFullAddr(addr.IP, addr.Port)
 131         return gonet.ListenTCP(e.s, fa, pn)
 132 }
 133
 134 func (e *TCPIPEndpoint) Close() error {
 135         e.s.RemoveNIC(1)
 136         return nil
 137 }
 138
 139 func NewTCPIPEndpoint(
 140         pc net.PacketConn,
 141         ipOur net.IP,
 142         mtu uint32,
 143 ) (*TCPIPEndpoint, error) {
 144         s := stack.New(stack.Options{
 145                 NetworkProtocols:   []stack.NetworkProtocolFactory{ipv6.NewProtocol},
 146                 TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol},
 147                 HandleLocal:        true,
 148         })
 149         e := TCPIPEndpoint{
 150                 mtu:      mtu,
 151                 s:        s,
 152                 pc:       pc,
 153                 readBuf:  make([]byte, 1<<16),
 154                 writeBuf: make([]byte, 1<<16),
 155                 ipToAddr: make(map[yaddr.Address]net.Addr),
 156                 pubToIP:  make(map[[ed25519.PublicKeySize]byte]yaddr.Address),
 157         }
 158         if err := s.CreateNIC(1, &e); err != nil {
 159                 return nil, fmt.Errorf("%+v", err)
 160         }
 161         protoAddr := tcpip.ProtocolAddress{
 162                 Protocol:          ipv6.ProtocolNumber,
 163                 AddressWithPrefix: tcpip.Address(ipOur).WithPrefix(),
 164         }
 165         if err := s.AddProtocolAddress(1, protoAddr, stack.AddressProperties{}); err != nil {
 166                 return nil, fmt.Errorf("%+v", err)
 167         }
 168         s.AddRoute(tcpip.Route{Destination: header.IPv6EmptySubnet, NIC: 1})
 169         go func() {
 170                 var n int
 171                 var from net.Addr
 172                 var err error
 173                 var pub [ed25519.PublicKeySize]byte
 174                 for {
 175                         n, from, err = pc.ReadFrom(e.readBuf)
 176                         if err != nil {
 177                                 log.Println(err)
 178                                 break
 179                         }
 180                         copy(pub[:], from.(iwt.Addr))
 181                         ip, ok := e.pubToIP[pub]
 182                         if !ok {
 183                                 copy(ip[:], yaddr.AddrForKey(ed25519.PublicKey(pub[:]))[:])
 184                                 e.pubToIP[pub] = ip
 185                                 e.ipToAddr[ip] = from
 186                         }
 187                         pkb := stack.NewPacketBuffer(stack.PacketBufferOptions{
 188                                 Payload: bufferv2.MakeWithData(e.readBuf[:n]),
 189                         })
 190                         e.d.DeliverNetworkPacket(ipv6.ProtocolNumber, pkb)
 191                 }
 192         }()
 193         return &e, nil
 194 }