Files
Reticulum-Go/pkg/link/link.go

885 lines
20 KiB
Go

package link
import (
"crypto/aes"
"crypto/cipher"
"crypto/ed25519"
"crypto/rand"
"encoding/hex"
"errors"
"fmt"
"io"
"log"
"sync"
"time"
"github.com/Sudo-Ivan/reticulum-go/pkg/common"
"github.com/Sudo-Ivan/reticulum-go/pkg/destination"
"github.com/Sudo-Ivan/reticulum-go/pkg/identity"
"github.com/Sudo-Ivan/reticulum-go/pkg/packet"
"github.com/Sudo-Ivan/reticulum-go/pkg/pathfinder"
"github.com/Sudo-Ivan/reticulum-go/pkg/resolver"
"github.com/Sudo-Ivan/reticulum-go/pkg/resource"
"github.com/Sudo-Ivan/reticulum-go/pkg/transport"
)
const (
CURVE = "Curve25519"
ESTABLISHMENT_TIMEOUT_PER_HOP = 6
KEEPALIVE_TIMEOUT_FACTOR = 4
STALE_GRACE = 2
KEEPALIVE = 360
STALE_TIME = 720
ACCEPT_NONE = 0x00
ACCEPT_ALL = 0x01
ACCEPT_APP = 0x02
STATUS_PENDING = 0x00
STATUS_ACTIVE = 0x01
STATUS_CLOSED = 0x02
STATUS_FAILED = 0x03
PROVE_NONE = 0x00
PROVE_ALL = 0x01
PROVE_APP = 0x02
WATCHDOG_MIN_SLEEP = 0.025
WATCHDOG_INTERVAL = 0.1
)
type Link struct {
mutex sync.RWMutex
destination *destination.Destination
status byte
networkInterface common.NetworkInterface
establishedAt time.Time
lastInbound time.Time
lastOutbound time.Time
lastDataReceived time.Time
lastDataSent time.Time
pathFinder *pathfinder.PathFinder
remoteIdentity *identity.Identity
sessionKey []byte
linkID []byte
rtt float64
establishmentRate float64
establishedCallback func(*Link)
closedCallback func(*Link)
packetCallback func([]byte, *packet.Packet)
identifiedCallback func(*Link, *identity.Identity)
teardownReason byte
hmacKey []byte
transport *transport.Transport
rssi float64
snr float64
q float64
resourceCallback func(interface{}) bool
resourceStartedCallback func(interface{})
resourceConcludedCallback func(interface{})
resourceStrategy byte
proofStrategy byte
proofCallback func(*packet.Packet) bool
trackPhyStats bool
watchdogLock bool
watchdogActive bool
establishmentTimeout time.Duration
keepalive time.Duration
staleTime time.Duration
initiator bool
}
func NewLink(dest *destination.Destination, transport *transport.Transport, networkIface common.NetworkInterface, establishedCallback func(*Link), closedCallback func(*Link)) *Link {
return &Link{
destination: dest,
status: STATUS_PENDING,
transport: transport,
networkInterface: networkIface,
establishedCallback: establishedCallback,
closedCallback: closedCallback,
establishedAt: time.Time{}, // Zero time until established
lastInbound: time.Time{},
lastOutbound: time.Time{},
lastDataReceived: time.Time{},
lastDataSent: time.Time{},
pathFinder: pathfinder.NewPathFinder(),
watchdogLock: false,
watchdogActive: false,
establishmentTimeout: time.Duration(ESTABLISHMENT_TIMEOUT_PER_HOP * float64(time.Second)),
keepalive: time.Duration(KEEPALIVE * float64(time.Second)),
staleTime: time.Duration(STALE_TIME * float64(time.Second)),
initiator: false,
}
}
func (l *Link) Establish() error {
l.mutex.Lock()
defer l.mutex.Unlock()
if l.status != STATUS_PENDING {
log.Printf("[DEBUG-3] Cannot establish link: invalid status %d", l.status)
return errors.New("link already established or failed")
}
destPublicKey := l.destination.GetPublicKey()
if destPublicKey == nil {
log.Printf("[DEBUG-3] Cannot establish link: destination has no public key")
return errors.New("destination has no public key")
}
log.Printf("[DEBUG-4] Creating link request packet for destination %x", destPublicKey[:8])
p := &packet.Packet{
HeaderType: packet.HeaderType1,
PacketType: packet.PacketTypeLinkReq,
TransportType: 0,
Context: packet.ContextLinkIdentify,
ContextFlag: packet.FlagUnset,
Hops: 0,
DestinationType: l.destination.GetType(),
DestinationHash: l.destination.GetHash(),
Data: l.linkID,
CreateReceipt: true,
}
if err := p.Pack(); err != nil {
log.Printf("[DEBUG-3] Failed to pack link request packet: %v", err)
return err
}
log.Printf("[DEBUG-4] Sending link request packet with ID %x", l.linkID[:8])
return l.transport.SendPacket(p)
}
func (l *Link) Identify(id *identity.Identity) error {
if !l.IsActive() {
return errors.New("link not active")
}
p := &packet.Packet{
HeaderType: packet.HeaderType1,
PacketType: packet.PacketTypeData,
TransportType: 0,
Context: packet.ContextLinkIdentify,
ContextFlag: packet.FlagUnset,
Hops: 0,
DestinationType: l.destination.GetType(),
DestinationHash: l.destination.GetHash(),
Data: id.GetPublicKey(),
CreateReceipt: true,
}
if err := p.Pack(); err != nil {
return err
}
return l.transport.SendPacket(p)
}
func (l *Link) HandleIdentification(data []byte) error {
l.mutex.Lock()
defer l.mutex.Unlock()
if len(data) < ed25519.PublicKeySize+ed25519.SignatureSize {
log.Printf("[DEBUG-3] Invalid identification data length: %d bytes", len(data))
return errors.New("invalid identification data length")
}
pubKey := data[:ed25519.PublicKeySize]
signature := data[ed25519.PublicKeySize:]
log.Printf("[DEBUG-4] Processing identification from public key %x", pubKey[:8])
remoteIdentity := identity.FromPublicKey(pubKey)
if remoteIdentity == nil {
log.Printf("[DEBUG-3] Invalid remote identity from public key %x", pubKey[:8])
return errors.New("invalid remote identity")
}
signData := append(l.linkID, pubKey...)
if !remoteIdentity.Verify(signData, signature) {
log.Printf("[DEBUG-3] Invalid signature from remote identity %x", pubKey[:8])
return errors.New("invalid signature")
}
log.Printf("[DEBUG-4] Remote identity verified successfully: %x", pubKey[:8])
l.remoteIdentity = remoteIdentity
if l.identifiedCallback != nil {
log.Printf("[DEBUG-4] Executing identified callback for remote identity %x", pubKey[:8])
l.identifiedCallback(l, remoteIdentity)
}
return nil
}
func (l *Link) Request(path string, data []byte, timeout time.Duration) (*RequestReceipt, error) {
l.mutex.Lock()
defer l.mutex.Unlock()
if l.status != STATUS_ACTIVE {
return nil, errors.New("link not active")
}
requestID := make([]byte, 16)
if _, err := rand.Read(requestID); err != nil {
return nil, err
}
// Create request message
reqMsg := make([]byte, 0)
reqMsg = append(reqMsg, requestID...)
reqMsg = append(reqMsg, []byte(path)...)
if data != nil {
reqMsg = append(reqMsg, data...)
}
receipt := &RequestReceipt{
requestID: requestID,
status: STATUS_PENDING,
sentAt: time.Now(),
}
// Send request
err := l.SendPacket(reqMsg)
if err != nil {
return nil, err
}
// Set timeout
if timeout > 0 {
go func() {
time.Sleep(timeout)
l.mutex.Lock()
if receipt.status == STATUS_PENDING {
receipt.status = STATUS_FAILED
}
l.mutex.Unlock()
}()
}
return receipt, nil
}
type RequestReceipt struct {
mutex sync.RWMutex
requestID []byte
status byte
sentAt time.Time
receivedAt time.Time
response []byte
}
func (r *RequestReceipt) GetRequestID() []byte {
r.mutex.RLock()
defer r.mutex.RUnlock()
return append([]byte{}, r.requestID...)
}
func (r *RequestReceipt) GetStatus() byte {
r.mutex.RLock()
defer r.mutex.RUnlock()
return r.status
}
func (r *RequestReceipt) GetResponse() []byte {
r.mutex.RLock()
defer r.mutex.RUnlock()
if r.response == nil {
return nil
}
return append([]byte{}, r.response...)
}
func (r *RequestReceipt) GetResponseTime() float64 {
r.mutex.RLock()
defer r.mutex.RUnlock()
if r.receivedAt.IsZero() {
return 0
}
return r.receivedAt.Sub(r.sentAt).Seconds()
}
func (r *RequestReceipt) Concluded() bool {
status := r.GetStatus()
return status == STATUS_ACTIVE || status == STATUS_FAILED
}
func (l *Link) TrackPhyStats(track bool) {
l.mutex.Lock()
defer l.mutex.Unlock()
l.trackPhyStats = track
}
func (l *Link) UpdatePhyStats(rssi, snr, q float64) {
l.mutex.Lock()
defer l.mutex.Unlock()
if l.trackPhyStats {
l.rssi = rssi
l.snr = snr
l.q = q
}
}
func (l *Link) GetRSSI() float64 {
l.mutex.RLock()
defer l.mutex.RUnlock()
if !l.trackPhyStats {
return 0
}
return l.rssi
}
func (l *Link) GetSNR() float64 {
l.mutex.RLock()
defer l.mutex.RUnlock()
if !l.trackPhyStats {
return 0
}
return l.snr
}
func (l *Link) GetQ() float64 {
l.mutex.RLock()
defer l.mutex.RUnlock()
if !l.trackPhyStats {
return 0
}
return l.q
}
func (l *Link) GetEstablishmentRate() float64 {
l.mutex.RLock()
defer l.mutex.RUnlock()
return l.establishmentRate
}
func (l *Link) GetAge() float64 {
l.mutex.RLock()
defer l.mutex.RUnlock()
if l.establishedAt.IsZero() {
return 0
}
return time.Since(l.establishedAt).Seconds()
}
func (l *Link) NoInboundFor() float64 {
l.mutex.RLock()
defer l.mutex.RUnlock()
if l.lastInbound.IsZero() {
return 0
}
return time.Since(l.lastInbound).Seconds()
}
func (l *Link) NoOutboundFor() float64 {
l.mutex.RLock()
defer l.mutex.RUnlock()
if l.lastOutbound.IsZero() {
return 0
}
return time.Since(l.lastOutbound).Seconds()
}
func (l *Link) NoDataFor() float64 {
l.mutex.RLock()
defer l.mutex.RUnlock()
lastData := l.lastDataReceived
if l.lastDataSent.After(lastData) {
lastData = l.lastDataSent
}
if lastData.IsZero() {
return 0
}
return time.Since(lastData).Seconds()
}
func (l *Link) InactiveFor() float64 {
l.mutex.RLock()
defer l.mutex.RUnlock()
lastActivity := l.lastInbound
if l.lastOutbound.After(lastActivity) {
lastActivity = l.lastOutbound
}
if lastActivity.IsZero() {
return 0
}
return time.Since(lastActivity).Seconds()
}
func (l *Link) GetRemoteIdentity() *identity.Identity {
l.mutex.RLock()
defer l.mutex.RUnlock()
return l.remoteIdentity
}
func (l *Link) Teardown() {
l.mutex.Lock()
defer l.mutex.Unlock()
if l.status == STATUS_ACTIVE {
l.status = STATUS_CLOSED
if l.closedCallback != nil {
l.closedCallback(l)
}
}
}
func (l *Link) SetLinkClosedCallback(callback func(*Link)) {
l.mutex.Lock()
defer l.mutex.Unlock()
l.closedCallback = callback
}
func (l *Link) SetPacketCallback(callback func([]byte, *packet.Packet)) {
l.mutex.Lock()
defer l.mutex.Unlock()
l.packetCallback = callback
}
func (l *Link) SetResourceCallback(callback func(interface{}) bool) {
l.mutex.Lock()
defer l.mutex.Unlock()
l.resourceCallback = callback
}
func (l *Link) SetResourceStartedCallback(callback func(interface{})) {
l.mutex.Lock()
defer l.mutex.Unlock()
l.resourceStartedCallback = callback
}
func (l *Link) SetResourceConcludedCallback(callback func(interface{})) {
l.mutex.Lock()
defer l.mutex.Unlock()
l.resourceConcludedCallback = callback
}
func (l *Link) SetRemoteIdentifiedCallback(callback func(*Link, *identity.Identity)) {
l.mutex.Lock()
defer l.mutex.Unlock()
l.identifiedCallback = callback
}
func (l *Link) SetResourceStrategy(strategy byte) error {
if strategy != ACCEPT_NONE && strategy != ACCEPT_ALL && strategy != ACCEPT_APP {
return errors.New("unsupported resource strategy")
}
l.mutex.Lock()
defer l.mutex.Unlock()
l.resourceStrategy = strategy
return nil
}
func (l *Link) SendPacket(data []byte) error {
l.mutex.Lock()
defer l.mutex.Unlock()
if l.status != STATUS_ACTIVE {
log.Printf("[DEBUG-3] Cannot send packet: link not active (status: %d)", l.status)
return errors.New("link not active")
}
log.Printf("[DEBUG-4] Encrypting packet of %d bytes", len(data))
encrypted, err := l.encrypt(data)
if err != nil {
log.Printf("[DEBUG-3] Failed to encrypt packet: %v", err)
return err
}
p := &packet.Packet{
HeaderType: packet.HeaderType1,
PacketType: packet.PacketTypeData,
TransportType: 0,
Context: packet.ContextNone,
ContextFlag: packet.FlagUnset,
Hops: 0,
DestinationType: l.destination.GetType(),
DestinationHash: l.destination.GetHash(),
Data: encrypted,
CreateReceipt: false,
}
if err := p.Pack(); err != nil {
return err
}
log.Printf("[DEBUG-4] Sending encrypted packet of %d bytes", len(encrypted))
l.lastOutbound = time.Now()
l.lastDataSent = time.Now()
return l.transport.SendPacket(p)
}
func (l *Link) HandleInbound(data []byte) error {
l.mutex.Lock()
defer l.mutex.Unlock()
if l.status != STATUS_ACTIVE {
log.Printf("[DEBUG-3] Dropping inbound packet: link not active (status: %d)", l.status)
return errors.New("link not active")
}
// Decode and log packet details
l.decodePacket(data)
// Decrypt if we have a session key
if l.sessionKey != nil {
decrypted, err := l.decrypt(data)
if err != nil {
log.Printf("[DEBUG-3] Failed to decrypt packet: %v", err)
return err
}
data = decrypted
}
l.lastInbound = time.Now()
l.lastDataReceived = time.Now()
if l.packetCallback != nil {
l.packetCallback(data, nil)
}
return nil
}
func (l *Link) encrypt(data []byte) ([]byte, error) {
if l.sessionKey == nil {
return nil, errors.New("no session key available")
}
block, err := aes.NewCipher(l.sessionKey)
if err != nil {
return nil, err
}
// Generate IV
iv := make([]byte, aes.BlockSize)
if _, err := io.ReadFull(rand.Reader, iv); err != nil {
return nil, err
}
// Add PKCS7 padding
padding := aes.BlockSize - len(data)%aes.BlockSize
padtext := make([]byte, len(data)+padding)
copy(padtext, data)
for i := len(data); i < len(padtext); i++ {
padtext[i] = byte(padding)
}
// Encrypt
mode := cipher.NewCBCEncrypter(block, iv)
ciphertext := make([]byte, len(padtext))
mode.CryptBlocks(ciphertext, padtext)
// Prepend IV to ciphertext
return append(iv, ciphertext...), nil
}
func (l *Link) decrypt(data []byte) ([]byte, error) {
if l.sessionKey == nil {
return nil, errors.New("no session key available")
}
block, err := aes.NewCipher(l.sessionKey)
if err != nil {
return nil, err
}
if len(data) < aes.BlockSize {
return nil, errors.New("ciphertext too short")
}
iv := data[:aes.BlockSize]
ciphertext := data[aes.BlockSize:]
if len(ciphertext)%aes.BlockSize != 0 {
return nil, errors.New("ciphertext is not a multiple of block size")
}
mode := cipher.NewCBCDecrypter(block, iv)
plaintext := make([]byte, len(ciphertext))
mode.CryptBlocks(plaintext, ciphertext)
// Remove PKCS7 padding
padding := int(plaintext[len(plaintext)-1])
if padding > aes.BlockSize || padding == 0 {
return nil, errors.New("invalid padding")
}
for i := len(plaintext) - padding; i < len(plaintext); i++ {
if plaintext[i] != byte(padding) {
return nil, errors.New("invalid padding")
}
}
return plaintext[:len(plaintext)-padding], nil
}
func (l *Link) GetRTT() float64 {
l.mutex.RLock()
defer l.mutex.RUnlock()
return l.rtt
}
func (l *Link) SetRTT(rtt float64) {
l.mutex.Lock()
defer l.mutex.Unlock()
l.rtt = rtt
}
func (l *Link) GetStatus() byte {
l.mutex.RLock()
defer l.mutex.RUnlock()
return l.status
}
func (l *Link) IsActive() bool {
return l.GetStatus() == STATUS_ACTIVE
}
func (l *Link) SendResource(res *resource.Resource) error {
l.mutex.Lock()
defer l.mutex.Unlock()
if l.status != STATUS_ACTIVE {
l.teardownReason = STATUS_FAILED
return errors.New("link not active")
}
// Activate the resource
res.Activate()
// Send the resource data as packets
buffer := make([]byte, resource.DEFAULT_SEGMENT_SIZE)
for {
n, err := res.Read(buffer)
if err == io.EOF {
break
}
if err != nil {
l.teardownReason = STATUS_FAILED
return fmt.Errorf("error reading resource: %v", err)
}
if err := l.SendPacket(buffer[:n]); err != nil {
l.teardownReason = STATUS_FAILED
return fmt.Errorf("error sending resource packet: %v", err)
}
}
return nil
}
func (l *Link) maintainLink() {
ticker := time.NewTicker(time.Second * KEEPALIVE)
defer ticker.Stop()
for range ticker.C {
if l.status != STATUS_ACTIVE {
return
}
inactiveTime := l.InactiveFor()
if inactiveTime > float64(STALE_TIME) {
l.mutex.Lock()
l.teardownReason = STATUS_FAILED
l.mutex.Unlock()
l.Teardown()
return
}
noDataTime := l.NoDataFor()
if noDataTime > float64(KEEPALIVE) {
l.mutex.Lock()
err := l.SendPacket([]byte{})
if err != nil {
l.teardownReason = STATUS_FAILED
l.mutex.Unlock()
l.Teardown()
return
}
l.mutex.Unlock()
}
}
}
func (l *Link) Start() {
go l.maintainLink()
}
func (l *Link) SetProofStrategy(strategy byte) error {
if strategy != PROVE_NONE && strategy != PROVE_ALL && strategy != PROVE_APP {
return errors.New("invalid proof strategy")
}
l.mutex.Lock()
defer l.mutex.Unlock()
l.proofStrategy = strategy
return nil
}
func (l *Link) SetProofCallback(callback func(*packet.Packet) bool) {
l.mutex.Lock()
defer l.mutex.Unlock()
l.proofCallback = callback
}
func (l *Link) HandleProofRequest(packet *packet.Packet) bool {
l.mutex.RLock()
defer l.mutex.RUnlock()
switch l.proofStrategy {
case PROVE_NONE:
return false
case PROVE_ALL:
return true
case PROVE_APP:
if l.proofCallback != nil {
return l.proofCallback(packet)
}
return false
default:
return false
}
}
func (l *Link) decodePacket(data []byte) {
if len(data) < 1 {
log.Printf("[DEBUG-7] Invalid packet: zero length")
return
}
packetType := data[0]
log.Printf("[DEBUG-7] Packet Analysis:")
log.Printf("[DEBUG-7] - Size: %d bytes", len(data))
log.Printf("[DEBUG-7] - Type: 0x%02x", packetType)
switch packetType {
case packet.PacketTypeData:
log.Printf("[DEBUG-7] - Type Description: Data Packet")
if len(data) > 1 {
log.Printf("[DEBUG-7] - Payload Size: %d bytes", len(data)-1)
}
case packet.PacketTypeLinkReq:
log.Printf("[DEBUG-7] - Type Description: Link Management")
if len(data) > 32 {
log.Printf("[DEBUG-7] - Link ID: %x", data[1:33])
}
case packet.PacketTypeAnnounce:
log.Printf("[DEBUG-7] Received announce packet (%d bytes)", len(data))
if len(data) < packet.MinAnnounceSize {
log.Printf("[DEBUG-3] Announce packet too short: %d bytes", len(data))
return
}
destHash := data[2:18]
encKey := data[18:50]
signKey := data[50:82]
nameHash := data[82:92]
randomHash := data[92:102]
signature := data[102:166]
appData := data[166:]
pubKey := append(encKey, signKey...)
validationData := make([]byte, 0, 164)
validationData = append(validationData, destHash...)
validationData = append(validationData, encKey...)
validationData = append(validationData, signKey...)
validationData = append(validationData, nameHash...)
validationData = append(validationData, randomHash...)
if identity.ValidateAnnounce(validationData, destHash, pubKey, signature, appData) {
log.Printf("[DEBUG-4] Valid announce from %x", pubKey[:8])
if err := l.transport.HandleAnnounce(destHash, l.networkInterface); err != nil {
log.Printf("[DEBUG-3] Failed to handle announce: %v", err)
}
} else {
log.Printf("[DEBUG-3] Invalid announce signature from %x", pubKey[:8])
}
case packet.PacketTypeProof:
log.Printf("[DEBUG-7] - Type Description: RNS Discovery")
if len(data) > 17 {
searchHash := data[1:17]
log.Printf("[DEBUG-7] - Searching for Hash: %x", searchHash)
if id, err := resolver.ResolveIdentity(hex.EncodeToString(searchHash)); err == nil {
log.Printf("[DEBUG-7] - Found matching identity: %s", id.GetHexHash())
}
}
default:
log.Printf("[DEBUG-7] - Type Description: Unknown (0x%02x)", packetType)
log.Printf("[DEBUG-7] - Raw Hex: %x", data)
}
}
// Helper function for min of two ints
func min(a, b int) int {
if a < b {
return a
}
return b
}
func (l *Link) startWatchdog() {
if l.watchdogActive {
return
}
l.watchdogActive = true
go l.watchdog()
}
func (l *Link) watchdog() {
for l.status != STATUS_CLOSED {
l.mutex.Lock()
if l.watchdogLock {
l.mutex.Unlock()
time.Sleep(time.Duration(WATCHDOG_MIN_SLEEP * float64(time.Second)))
continue
}
var sleepTime float64 = WATCHDOG_INTERVAL
switch l.status {
case STATUS_ACTIVE:
lastActivity := l.lastInbound
if l.lastOutbound.After(lastActivity) {
lastActivity = l.lastOutbound
}
if time.Since(lastActivity) > l.keepalive {
if l.initiator {
l.SendPacket([]byte{}) // Keepalive packet
}
if time.Since(lastActivity) > l.staleTime {
l.status = STATUS_CLOSED
l.teardownReason = STATUS_FAILED
if l.closedCallback != nil {
l.closedCallback(l)
}
}
}
}
l.mutex.Unlock()
time.Sleep(time.Duration(sleepTime * float64(time.Second)))
}
l.watchdogActive = false
}