mirror of
https://github.com/KusakabeShi/EtherGuard-VPN.git
synced 2024-12-26 07:38:48 +01:00
606 lines
16 KiB
Go
606 lines
16 KiB
Go
/* SPDX-License-Identifier: MIT
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*
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* Copyright (C) 2017-2021 WireGuard LLC. All Rights Reserved.
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*/
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package device
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import (
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"bytes"
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"encoding/binary"
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"errors"
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"fmt"
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"net"
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"strconv"
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"sync"
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"sync/atomic"
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"time"
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"github.com/google/gopacket"
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"github.com/google/gopacket/layers"
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"golang.org/x/crypto/chacha20poly1305"
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"github.com/KusakabeSi/EtherGuardVPN/config"
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"github.com/KusakabeSi/EtherGuardVPN/conn"
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"github.com/KusakabeSi/EtherGuardVPN/path"
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"github.com/KusakabeSi/EtherGuardVPN/tap"
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)
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type QueueHandshakeElement struct {
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msgType path.Usage
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packet []byte
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endpoint conn.Endpoint
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buffer *[MaxMessageSize]byte
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}
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type QueueInboundElement struct {
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Type path.Usage
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sync.Mutex
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buffer *[MaxMessageSize]byte
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packet []byte
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counter uint64
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keypair *Keypair
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endpoint conn.Endpoint
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}
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// clearPointers clears elem fields that contain pointers.
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// This makes the garbage collector's life easier and
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// avoids accidentally keeping other objects around unnecessarily.
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// It also reduces the possible collateral damage from use-after-free bugs.
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func (elem *QueueInboundElement) clearPointers() {
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elem.buffer = nil
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elem.packet = nil
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elem.keypair = nil
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elem.endpoint = nil
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}
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/* Called when a new authenticated message has been received
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*
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* NOTE: Not thread safe, but called by sequential receiver!
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*/
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func (peer *Peer) keepKeyFreshReceiving() {
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if peer.timers.sentLastMinuteHandshake.Get() {
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return
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}
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keypair := peer.keypairs.Current()
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if keypair != nil && keypair.isInitiator && time.Since(keypair.created) > (RejectAfterTime-KeepaliveTimeout-RekeyTimeout) {
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peer.timers.sentLastMinuteHandshake.Set(true)
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peer.SendHandshakeInitiation(false)
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}
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}
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/* Receives incoming datagrams for the device
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*
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* Every time the bind is updated a new routine is started for
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* IPv4 and IPv6 (separately)
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*/
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func (device *Device) RoutineReceiveIncoming(recv conn.ReceiveFunc) {
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recvName := recv.PrettyName()
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defer func() {
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device.log.Verbosef("Routine: receive incoming %s - stopped", recvName)
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device.queue.decryption.wg.Done()
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device.queue.handshake.wg.Done()
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device.net.stopping.Done()
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}()
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device.log.Verbosef("Routine: receive incoming %s - started", recvName)
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// receive datagrams until conn is closed
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buffer := device.GetMessageBuffer()
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var (
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err error
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size int
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endpoint conn.Endpoint
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deathSpiral int
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)
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for {
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size, endpoint, err = recv(buffer[:])
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if err != nil {
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device.PutMessageBuffer(buffer)
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if errors.Is(err, net.ErrClosed) {
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return
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}
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device.log.Verbosef("Failed to receive %s packet: %v", recvName, err)
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if neterr, ok := err.(net.Error); ok && !neterr.Temporary() {
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return
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}
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if deathSpiral < 10 {
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deathSpiral++
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time.Sleep(time.Second / 3)
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buffer = device.GetMessageBuffer()
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continue
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}
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return
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}
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deathSpiral = 0
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if size < MinMessageSize {
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continue
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}
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// check size of packet
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packet := buffer[:size]
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msgType := path.Usage(packet[0])
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msgType_wg := msgType
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if msgType >= path.MessageTransportType {
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msgType_wg = path.MessageTransportType
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}
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var okay bool
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switch msgType_wg {
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// check if transport
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case path.MessageTransportType:
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// check size
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if len(packet) < MessageTransportSize {
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continue
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}
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// lookup key pair
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receiver := binary.LittleEndian.Uint32(
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packet[MessageTransportOffsetReceiver:MessageTransportOffsetCounter],
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)
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value := device.indexTable.Lookup(receiver)
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keypair := value.keypair
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if keypair == nil {
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continue
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}
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// check keypair expiry
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if keypair.created.Add(RejectAfterTime).Before(time.Now()) {
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continue
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}
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// create work element
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peer := value.peer
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elem := device.GetInboundElement()
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elem.Type = msgType
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elem.packet = packet
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elem.buffer = buffer
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elem.keypair = keypair
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elem.endpoint = endpoint
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elem.counter = 0
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elem.Mutex = sync.Mutex{}
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elem.Lock()
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// add to decryption queues
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if peer.isRunning.Get() {
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peer.queue.inbound.c <- elem
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device.queue.decryption.c <- elem
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buffer = device.GetMessageBuffer()
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} else {
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device.PutInboundElement(elem)
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}
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continue
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// otherwise it is a fixed size & handshake related packet
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case path.MessageInitiationType:
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okay = len(packet) == MessageInitiationSize
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case path.MessageResponseType:
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okay = len(packet) == MessageResponseSize
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case path.MessageCookieReplyType:
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okay = len(packet) == MessageCookieReplySize
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default:
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device.log.Verbosef("Received message with unknown type")
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}
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if okay {
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select {
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case device.queue.handshake.c <- QueueHandshakeElement{
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msgType: msgType,
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buffer: buffer,
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packet: packet,
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endpoint: endpoint,
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}:
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buffer = device.GetMessageBuffer()
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default:
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}
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}
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}
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}
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func (device *Device) RoutineDecryption(id int) {
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var nonce [chacha20poly1305.NonceSize]byte
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defer device.log.Verbosef("Routine: decryption worker %d - stopped", id)
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device.log.Verbosef("Routine: decryption worker %d - started", id)
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for elem := range device.queue.decryption.c {
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// split message into fields
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counter := elem.packet[MessageTransportOffsetCounter:MessageTransportOffsetContent]
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content := elem.packet[MessageTransportOffsetContent:]
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// decrypt and release to consumer
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var err error
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elem.counter = binary.LittleEndian.Uint64(counter)
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// copy counter to nonce
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binary.LittleEndian.PutUint64(nonce[0x4:0xc], elem.counter)
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elem.packet, err = elem.keypair.receive.Open(
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content[:0],
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nonce[:],
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content,
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nil,
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)
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if err != nil {
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elem.packet = nil
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}
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elem.Unlock()
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}
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}
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/* Handles incoming packets related to handshake
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*/
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func (device *Device) RoutineHandshake(id int) {
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defer func() {
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device.log.Verbosef("Routine: handshake worker %d - stopped", id)
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device.queue.encryption.wg.Done()
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}()
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device.log.Verbosef("Routine: handshake worker %d - started", id)
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for elem := range device.queue.handshake.c {
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// handle cookie fields and ratelimiting
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switch elem.msgType {
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case path.MessageCookieReplyType:
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// unmarshal packet
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var reply MessageCookieReply
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reader := bytes.NewReader(elem.packet)
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err := binary.Read(reader, binary.LittleEndian, &reply)
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if err != nil {
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device.log.Verbosef("Failed to decode cookie reply")
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goto skip
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}
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// lookup peer from index
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entry := device.indexTable.Lookup(reply.Receiver)
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if entry.peer == nil {
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goto skip
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}
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// consume reply
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if peer := entry.peer; peer.isRunning.Get() {
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device.log.Verbosef("Receiving cookie response from %s", elem.endpoint.DstToString())
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if !peer.cookieGenerator.ConsumeReply(&reply) {
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device.log.Verbosef("Could not decrypt invalid cookie response")
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}
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}
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goto skip
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case path.MessageInitiationType, path.MessageResponseType:
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// check mac fields and maybe ratelimit
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if !device.cookieChecker.CheckMAC1(elem.packet) {
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device.log.Verbosef("Received packet with invalid mac1")
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goto skip
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}
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// endpoints destination address is the source of the datagram
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if device.IsUnderLoad() {
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// verify MAC2 field
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if !device.cookieChecker.CheckMAC2(elem.packet, elem.endpoint.DstToBytes()) {
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device.SendHandshakeCookie(&elem)
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goto skip
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}
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// check ratelimiter
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if !device.rate.limiter.Allow(elem.endpoint.DstIP()) {
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goto skip
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}
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}
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default:
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device.log.Errorf("Invalid packet ended up in the handshake queue")
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goto skip
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}
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// handle handshake initiation/response content
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switch elem.msgType {
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case path.MessageInitiationType:
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// unmarshal
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var msg MessageInitiation
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reader := bytes.NewReader(elem.packet)
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err := binary.Read(reader, binary.LittleEndian, &msg)
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if err != nil {
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device.log.Errorf("Failed to decode initiation message")
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goto skip
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}
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// consume initiation
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peer := device.ConsumeMessageInitiation(&msg)
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if peer == nil {
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device.log.Verbosef("Received invalid initiation message from %s", elem.endpoint.DstToString())
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goto skip
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}
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// update timers
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peer.timersAnyAuthenticatedPacketTraversal()
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peer.timersAnyAuthenticatedPacketReceived()
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// update endpoint
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peer.SetEndpointFromPacket(elem.endpoint)
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device.log.Verbosef("%v - Received handshake initiation", peer)
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atomic.AddUint64(&peer.stats.rxBytes, uint64(len(elem.packet)))
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peer.SendHandshakeResponse()
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case path.MessageResponseType:
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// unmarshal
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var msg MessageResponse
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reader := bytes.NewReader(elem.packet)
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err := binary.Read(reader, binary.LittleEndian, &msg)
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if err != nil {
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device.log.Errorf("Failed to decode response message")
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goto skip
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}
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// consume response
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peer := device.ConsumeMessageResponse(&msg)
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if peer == nil {
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device.log.Verbosef("Received invalid response message from %s", elem.endpoint.DstToString())
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goto skip
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}
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// update endpoint
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peer.SetEndpointFromPacket(elem.endpoint)
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device.log.Verbosef("%v - Received handshake response", peer)
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atomic.AddUint64(&peer.stats.rxBytes, uint64(len(elem.packet)))
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// update timers
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peer.timersAnyAuthenticatedPacketTraversal()
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peer.timersAnyAuthenticatedPacketReceived()
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// derive keypair
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err = peer.BeginSymmetricSession()
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if err != nil {
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device.log.Errorf("%v - Failed to derive keypair: %v", peer, err)
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goto skip
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}
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peer.timersSessionDerived()
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peer.timersHandshakeComplete()
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peer.SendKeepalive()
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}
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skip:
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device.PutMessageBuffer(elem.buffer)
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}
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}
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func (peer *Peer) RoutineSequentialReceiver() {
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device := peer.device
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var peer_out *Peer
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defer func() {
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device.log.Verbosef("%v - Routine: sequential receiver - stopped", peer)
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peer.stopping.Done()
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}()
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device.log.Verbosef("%v - Routine: sequential receiver - started", peer)
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for elem := range peer.queue.inbound.c {
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if elem == nil {
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return
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}
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var EgHeader path.EgHeader
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var err error
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var src_nodeID config.Vertex
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var dst_nodeID config.Vertex
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var packet_type path.Usage
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should_process := false
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should_receive := false
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should_transfer := false
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elem.Lock()
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if elem.packet == nil {
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// decryption failed
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goto skip
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}
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if !elem.keypair.replayFilter.ValidateCounter(elem.counter, RejectAfterMessages) {
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goto skip
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}
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peer.SetEndpointFromPacket(elem.endpoint)
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if peer.ReceivedWithKeypair(elem.keypair) {
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peer.timersHandshakeComplete()
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peer.SendStagedPackets()
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}
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peer.keepKeyFreshReceiving()
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peer.timersAnyAuthenticatedPacketTraversal()
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peer.timersAnyAuthenticatedPacketReceived()
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atomic.AddUint64(&peer.stats.rxBytes, uint64(len(elem.packet)+MinMessageSize))
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if len(elem.packet) == 0 {
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device.log.Verbosef("%v - Receiving keepalive packet", peer)
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goto skip
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}
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peer.timersDataReceived()
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if len(elem.packet) <= path.EgHeaderLen {
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device.log.Errorf("Invalid EgHeader from peer %v", peer)
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goto skip
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}
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EgHeader, err = path.NewEgHeader(elem.packet[0:path.EgHeaderLen]) // EG header
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src_nodeID = EgHeader.GetSrc()
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dst_nodeID = EgHeader.GetDst()
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elem.packet = elem.packet[:EgHeader.GetPacketLength()+path.EgHeaderLen] // EG header + true packet
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packet_type = elem.Type
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peer.LastPingReceived = time.Now()
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if device.IsSuperNode {
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peer.LastPingReceived = time.Now()
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switch dst_nodeID {
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case config.ControlMessage:
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should_process = true
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case config.SuperNodeMessage:
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should_process = true
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default:
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device.log.Errorf("Invalid dst_nodeID received. Check your code for bug")
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}
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} else {
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switch dst_nodeID {
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case config.Broadcast:
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should_receive = true
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should_transfer = true
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case config.SuperNodeMessage:
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should_process = true
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case config.ControlMessage:
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packet := elem.packet[path.EgHeaderLen:] //true packet
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if device.CheckNoDup(packet) {
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should_process = true
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should_transfer = true
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} else {
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should_process = false
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should_transfer = false
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if device.LogLevel.LogTransit {
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fmt.Printf("Transit: Duplicate packet received from %d through %d , src_nodeID = %d . Dropeed.\n", peer.ID, device.ID, src_nodeID)
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}
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}
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case device.ID:
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if packet_type == path.NormalPacket {
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should_receive = true
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} else {
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should_process = true
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}
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default:
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if device.graph.Next(device.ID, dst_nodeID) != nil {
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should_transfer = true
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} else {
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device.log.Verbosef("No route to peer ID %v", dst_nodeID)
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}
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}
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}
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if should_transfer {
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l2ttl := EgHeader.GetTTL()
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if l2ttl == 0 {
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device.log.Verbosef("TTL is 0 %v", dst_nodeID)
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} else {
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EgHeader.SetTTL(l2ttl - 1)
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if dst_nodeID == config.Broadcast { //Regular transfer algorithm
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device.TransitBoardcastPacket(src_nodeID, peer.ID, elem.Type, elem.packet, MessageTransportOffsetContent)
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} else if dst_nodeID == config.ControlMessage { // Control Message will try send to every know node regardless the connectivity
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skip_list := make(map[config.Vertex]bool)
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skip_list[src_nodeID] = true //Don't send to conimg peer and source peer
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skip_list[peer.ID] = true
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device.SpreadPacket(skip_list, elem.Type, elem.packet, MessageTransportOffsetContent)
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} else {
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next_id := device.graph.Next(device.ID, dst_nodeID)
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if next_id != nil {
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device.peers.RLock()
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peer_out = device.peers.IDMap[*next_id]
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device.peers.RUnlock()
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if device.LogLevel.LogTransit {
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fmt.Printf("Transit: Transfer packet from %d through %d to %d\n", peer.ID, device.ID, peer_out.ID)
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}
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device.SendPacket(peer_out, elem.Type, elem.packet, MessageTransportOffsetContent)
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}
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}
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}
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}
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if should_process {
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if packet_type != path.NormalPacket {
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if device.LogLevel.LogControl {
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if peer.GetEndpointDstStr() != "" {
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fmt.Println("Control: Received From:" + peer.GetEndpointDstStr() + " " + device.sprint_received(packet_type, elem.packet[path.EgHeaderLen:]))
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}
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}
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err = device.process_received(packet_type, peer, elem.packet[path.EgHeaderLen:])
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if err != nil {
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device.log.Errorf(err.Error())
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}
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}
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}
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if should_receive { // Write message to tap device
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if packet_type == path.NormalPacket {
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if len(elem.packet) <= path.EgHeaderLen+12 {
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device.log.Errorf("Invalid normal packet: Ethernet packet too small from peer %v", peer.ID.ToString())
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goto skip
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}
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if device.LogLevel.LogNormal {
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packet_len := len(elem.packet) - path.EgHeaderLen
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fmt.Println("Normal: Reveived Normal packet From:" + peer.GetEndpointDstStr() + " SrcID:" + src_nodeID.ToString() + " DstID:" + dst_nodeID.ToString() + " Len:" + strconv.Itoa(packet_len))
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|
packet := gopacket.NewPacket(elem.packet[path.EgHeaderLen:], layers.LayerTypeEthernet, gopacket.Default)
|
|
fmt.Println(packet.Dump())
|
|
}
|
|
src_macaddr := tap.GetSrcMacAddr(elem.packet[path.EgHeaderLen:])
|
|
if !tap.IsNotUnicast(src_macaddr) {
|
|
val, ok := device.l2fib.Load(src_macaddr)
|
|
if ok {
|
|
idtime := val.(*IdAndTime)
|
|
if idtime.ID != src_nodeID {
|
|
idtime.ID = src_nodeID
|
|
if device.LogLevel.LogInternal {
|
|
fmt.Printf("Internal: L2FIB [%v -> %v] updated.\n", src_macaddr.String(), src_nodeID)
|
|
}
|
|
}
|
|
idtime.Time = time.Now()
|
|
} else {
|
|
device.l2fib.Store(src_macaddr, &IdAndTime{
|
|
ID: src_nodeID,
|
|
Time: time.Now(),
|
|
}) // Write to l2fib table
|
|
if device.LogLevel.LogInternal {
|
|
fmt.Printf("Internal: L2FIB [%v -> %v] added.\n", src_macaddr.String(), src_nodeID)
|
|
}
|
|
}
|
|
}
|
|
_, err = device.tap.device.Write(elem.buffer[:MessageTransportOffsetContent+len(elem.packet)], MessageTransportOffsetContent+path.EgHeaderLen)
|
|
if err != nil && !device.isClosed() {
|
|
device.log.Errorf("Failed to write packet to TUN device: %v", err)
|
|
}
|
|
if len(peer.queue.inbound.c) == 0 {
|
|
err = device.tap.device.Flush()
|
|
if err != nil {
|
|
peer.device.log.Errorf("Unable to flush packets: %v", err)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
skip:
|
|
device.PutMessageBuffer(elem.buffer)
|
|
device.PutInboundElement(elem)
|
|
}
|
|
}
|