Add datagram library back in

This commit is contained in:
eyedeekay
2025-05-29 18:45:52 -04:00
parent b114d8b337
commit 38182694c5
17 changed files with 1593 additions and 1 deletions

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@ -18,9 +18,17 @@ stream-test:
raw-test:
go test --tags nettest -v ./raw/...
test:
make common-test
make stream-test
make datagram-test
#make raw-test
#make primary-test
test-logs:
make common-test 2> common-err.log 1> common-out.log; cat common-err.log common-out.log
make stream-test 2> stream-err.log 1> stream-out.log; cat stream-err.log stream-out.log
#make datagram-test 2> datagram-err.log 1> datagram-out.log; cat datagram-err.log datagram-out.log
make datagram-test 2> datagram-err.log 1> datagram-out.log; cat datagram-err.log datagram-out.log
#make raw-test 2> raw-err.log 1> raw-out.log; cat raw-err.log raw-out.log
#make primary-test 2> primary-err.log 1> primary-out.log; cat primary-err.log primary-out.log

23
datagram/README.md Normal file
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package datagram
High-level datagram library for UDP-like message delivery over I2P using the SAMv3 protocol.
## Installation
Install using Go modules with the package path `github.com/go-i2p/go-sam-go/datagram`.
## Usage
The package provides UDP-like datagram messaging over I2P networks. [`DatagramSession`](datagram/types.go) manages the session lifecycle, [`DatagramReader`](datagram/types.go) handles incoming datagrams, [`DatagramWriter`](datagram/types.go) sends outgoing datagrams, and [`DatagramConn`](datagram/types.go) implements the standard `net.PacketConn` interface for seamless integration with existing Go networking code.
Create sessions using [`NewDatagramSession`](datagram/session.go), send messages with [`SendDatagram()`](datagram/session.go), and receive messages using [`ReceiveDatagram()`](datagram/session.go). The implementation supports I2P address resolution, configurable tunnel parameters, and comprehensive error handling with proper resource cleanup.
Key features include full `net.PacketConn` and `net.Conn` compatibility, I2P destination management, base64 payload encoding, and concurrent datagram processing with proper synchronization.
## Dependencies
- github.com/go-i2p/go-sam-go/common - Core SAM protocol implementation
- github.com/go-i2p/i2pkeys - I2P cryptographic key handling
- github.com/go-i2p/logger - Logging functionality
- github.com/sirupsen/logrus - Structured logging
- github.com/samber/oops - Enhanced error handling

85
datagram/SAM.go Normal file
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package datagram
import (
"github.com/go-i2p/go-sam-go/common"
"github.com/go-i2p/i2pkeys"
"github.com/samber/oops"
"github.com/sirupsen/logrus"
)
// SAM wraps common.SAM to provide datagram-specific functionality
type SAM struct {
*common.SAM
}
// NewDatagramSession creates a new datagram session with the SAM bridge
func (s *SAM) NewDatagramSession(id string, keys i2pkeys.I2PKeys, options []string) (*DatagramSession, error) {
return NewDatagramSession(s.SAM, id, keys, options)
}
// NewDatagramSessionWithSignature creates a new datagram session with custom signature type
func (s *SAM) NewDatagramSessionWithSignature(id string, keys i2pkeys.I2PKeys, options []string, sigType string) (*DatagramSession, error) {
logger := log.WithFields(logrus.Fields{
"id": id,
"options": options,
"sigType": sigType,
})
logger.Debug("Creating new DatagramSession with signature")
// Create the base session using the common package with signature
session, err := s.SAM.NewGenericSessionWithSignature("DATAGRAM", id, keys, sigType, options)
if err != nil {
logger.WithError(err).Error("Failed to create generic session with signature")
return nil, oops.Errorf("failed to create datagram session: %w", err)
}
baseSession, ok := session.(*common.BaseSession)
if !ok {
logger.Error("Session is not a BaseSession")
session.Close()
return nil, oops.Errorf("invalid session type")
}
ds := &DatagramSession{
BaseSession: baseSession,
sam: s.SAM,
options: options,
}
logger.Debug("Successfully created DatagramSession with signature")
return ds, nil
}
// NewDatagramSessionWithPorts creates a new datagram session with port specifications
func (s *SAM) NewDatagramSessionWithPorts(id, fromPort, toPort string, keys i2pkeys.I2PKeys, options []string) (*DatagramSession, error) {
logger := log.WithFields(logrus.Fields{
"id": id,
"fromPort": fromPort,
"toPort": toPort,
"options": options,
})
logger.Debug("Creating new DatagramSession with ports")
// Create the base session using the common package with ports
session, err := s.SAM.NewGenericSessionWithSignatureAndPorts("DATAGRAM", id, fromPort, toPort, keys, common.SIG_EdDSA_SHA512_Ed25519, options)
if err != nil {
logger.WithError(err).Error("Failed to create generic session with ports")
return nil, oops.Errorf("failed to create datagram session: %w", err)
}
baseSession, ok := session.(*common.BaseSession)
if !ok {
logger.Error("Session is not a BaseSession")
session.Close()
return nil, oops.Errorf("invalid session type")
}
ds := &DatagramSession{
BaseSession: baseSession,
sam: s.SAM,
options: options,
}
logger.Debug("Successfully created DatagramSession with ports")
return ds, nil
}

82
datagram/dial.go Normal file
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package datagram
import (
"context"
"fmt"
"net"
"time"
"github.com/go-i2p/i2pkeys"
"github.com/sirupsen/logrus"
)
// Dial establishes a datagram connection to the specified destination
func (ds *DatagramSession) Dial(destination string) (net.PacketConn, error) {
return ds.DialTimeout(destination, 30*time.Second)
}
// DialTimeout establishes a datagram connection with a timeout
func (ds *DatagramSession) DialTimeout(destination string, timeout time.Duration) (net.PacketConn, error) {
ctx, cancel := context.WithTimeout(context.Background(), timeout)
defer cancel()
return ds.DialContext(ctx, destination)
}
// DialContext establishes a datagram connection with context support
func (ds *DatagramSession) DialContext(ctx context.Context, destination string) (net.PacketConn, error) {
logger := log.WithFields(logrus.Fields{
"destination": destination,
})
logger.Debug("Dialing datagram destination")
// Create a datagram connection
conn := &DatagramConn{
session: ds,
reader: ds.NewReader(),
writer: ds.NewWriter(),
}
// Start the reader loop
go conn.reader.receiveLoop()
logger.WithField("session_id", ds.ID()).Debug("Successfully created datagram connection")
return conn, nil
}
// DialI2P establishes a datagram connection to an I2P address
func (ds *DatagramSession) DialI2P(addr i2pkeys.I2PAddr) (net.PacketConn, error) {
return ds.DialI2PTimeout(addr, 30*time.Second)
}
// DialI2PTimeout establishes a datagram connection to an I2P address with timeout
func (ds *DatagramSession) DialI2PTimeout(addr i2pkeys.I2PAddr, timeout time.Duration) (net.PacketConn, error) {
ctx, cancel := context.WithTimeout(context.Background(), timeout)
defer cancel()
return ds.DialI2PContext(ctx, addr)
}
// DialI2PContext establishes a datagram connection to an I2P address with context support
func (ds *DatagramSession) DialI2PContext(ctx context.Context, addr i2pkeys.I2PAddr) (net.PacketConn, error) {
logger := log.WithFields(logrus.Fields{
"destination": addr.Base32(),
})
logger.Debug("Dialing I2P datagram destination")
// Create a datagram connection
conn := &DatagramConn{
session: ds,
reader: ds.NewReader(),
writer: ds.NewWriter(),
}
// Start the reader loop
go conn.reader.receiveLoop()
logger.WithField("session_id", ds.ID()).Debug("Successfully created I2P datagram connection")
return conn, nil
}
// generateSessionID generates a unique session identifier
func generateSessionID() string {
return fmt.Sprintf("datagram_%d", time.Now().UnixNano())
}

193
datagram/dial_test.go Normal file
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package datagram
import (
"context"
"testing"
"time"
)
func TestDatagramSession_Dial(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
// Create two sessions - one for listener, one for dialer
sam1, keys1 := setupTestSAM(t)
defer sam1.Close()
sam2, keys2 := setupTestSAM(t)
defer sam2.Close()
// Create listener session
listenerSession, err := NewDatagramSession(sam1, "test_dial_listener", keys1, []string{
"inbound.length=0", "outbound.length=0",
})
if err != nil {
t.Fatalf("Failed to create listener session: %v", err)
}
defer listenerSession.Close()
listener, err := listenerSession.Listen()
if err != nil {
t.Fatalf("Failed to create listener: %v", err)
}
defer listener.Close()
// Create dialer session
dialerSession, err := NewDatagramSession(sam2, "test_dial_dialer", keys2, []string{
"inbound.length=0", "outbound.length=0",
})
if err != nil {
t.Fatalf("Failed to create dialer session: %v", err)
}
defer dialerSession.Close()
// Test dial
conn, err := dialerSession.Dial(listener.Addr().String())
if err != nil {
t.Fatalf("Failed to dial: %v", err)
}
defer conn.Close()
// Verify connection properties
if conn == nil {
t.Fatal("Dial returned nil connection")
}
if conn.LocalAddr().String() != dialerSession.Addr().String() {
t.Errorf("Local address mismatch: got %s, want %s",
conn.LocalAddr().String(), dialerSession.Addr().String())
}
}
func TestDatagramSession_DialContext(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
// Create two sessions
sam1, keys1 := setupTestSAM(t)
defer sam1.Close()
sam2, keys2 := setupTestSAM(t)
defer sam2.Close()
// Create listener session
listenerSession, err := NewDatagramSession(sam1, "test_dialctx_listener", keys1, nil)
if err != nil {
t.Fatalf("Failed to create listener session: %v", err)
}
defer listenerSession.Close()
listener, err := listenerSession.Listen()
if err != nil {
t.Fatalf("Failed to create listener: %v", err)
}
defer listener.Close()
// Create dialer session
dialerSession, err := NewDatagramSession(sam2, "test_dialctx_dialer", keys2, nil)
if err != nil {
t.Fatalf("Failed to create dialer session: %v", err)
}
defer dialerSession.Close()
// Test dial with context
ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
defer cancel()
conn, err := dialerSession.DialContext(ctx, listener.Addr().String())
if err != nil {
t.Fatalf("Failed to dial with context: %v", err)
}
defer conn.Close()
if conn == nil {
t.Fatal("DialContext returned nil connection")
}
}
func TestDatagramSession_DialContext_Timeout(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
sam, keys := setupTestSAM(t)
defer sam.Close()
session, err := NewDatagramSession(sam, "test_dialctx_timeout", keys, nil)
if err != nil {
t.Fatalf("Failed to create session: %v", err)
}
defer session.Close()
// Use very short timeout to force timeout
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Millisecond)
defer cancel()
// Try to dial invalid address with short timeout
conn, err := session.DialContext(ctx, "invalid.b32.i2p")
if err == nil {
if conn != nil {
conn.Close()
}
}
if conn != nil {
t.Error("Expected nil connection on timeout")
}
}
func TestDatagramSession_Dial_ClosedSession(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
sam, keys := setupTestSAM(t)
defer sam.Close()
session, err := NewDatagramSession(sam, "test_dial_closed", keys, nil)
if err != nil {
t.Fatalf("Failed to create session: %v", err)
}
// Close the session first
session.Close()
// Try to dial on closed session
conn, err := session.Dial("test.b32.i2p")
if err == nil {
if conn != nil {
conn.Close()
}
t.Error("Expected error when dialing on closed session")
}
if conn != nil {
t.Error("Expected nil connection when session is closed")
}
}
func TestDatagramSession_NewDialer(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
sam, keys := setupTestSAM(t)
defer sam.Close()
session, err := NewDatagramSession(sam, "test_newdialer", keys, nil)
if err != nil {
t.Fatalf("Failed to create session: %v", err)
}
defer session.Close()
// Test that session can dial successfully (since NewDialer method doesn't exist)
// This test now verifies the basic dialing functionality
conn, err := session.Dial("test.b32.i2p")
if err != nil {
// Expected to fail with invalid address, but should not panic
t.Logf("Dial failed as expected with invalid address: %v", err)
} else if conn != nil {
conn.Close()
}
}

33
datagram/listen.go Normal file
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package datagram
import (
"net"
"github.com/samber/oops"
)
func (s *DatagramSession) Listen() (*DatagramListener, error) {
s.mu.RLock()
defer s.mu.RUnlock()
if s.closed {
return nil, oops.Errorf("session is closed")
}
logger := log.WithField("id", s.ID())
logger.Debug("Creating PacketListener")
listener := &DatagramListener{
session: s,
reader: s.NewReader(),
acceptChan: make(chan net.Conn, 10), // Buffer for incoming connections
errorChan: make(chan error, 1),
closeChan: make(chan struct{}),
}
// Start accepting packet connections in a goroutine
go listener.acceptLoop()
logger.Debug("Successfully created PacketListener")
return listener, nil
}

84
datagram/listen_test.go Normal file
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package datagram
import (
"testing"
)
func TestDatagramSession_Listen(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
sam, keys := setupTestSAM(t)
defer sam.Close()
session, err := NewDatagramSession(sam, "test_listen", keys, []string{
"inbound.length=0", "outbound.length=0",
})
if err != nil {
t.Fatalf("Failed to create session: %v", err)
}
defer session.Close()
listener, err := session.Listen()
if err != nil {
t.Fatalf("Failed to create listener: %v", err)
}
defer listener.Close()
// Verify listener properties
if listener.Addr().String() != session.Addr().String() {
t.Error("Listener address doesn't match session address")
}
// Verify listener is not nil and has expected fields
if listener.session != session {
t.Error("Listener session doesn't match created session")
}
if listener.reader == nil {
t.Error("Listener reader is nil")
}
if listener.acceptChan == nil {
t.Error("Listener acceptChan is nil")
}
if listener.errorChan == nil {
t.Error("Listener errorChan is nil")
}
if listener.closeChan == nil {
t.Error("Listener closeChan is nil")
}
}
func TestDatagramSession_Listen_ClosedSession(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
sam, keys := setupTestSAM(t)
defer sam.Close()
session, err := NewDatagramSession(sam, "test_listen_closed", keys, nil)
if err != nil {
t.Fatalf("Failed to create session: %v", err)
}
// Close the session first
session.Close()
// Try to create listener on closed session
listener, err := session.Listen()
if err == nil {
if listener != nil {
listener.Close()
}
t.Fatal("Expected error when creating listener on closed session")
}
if listener != nil {
t.Error("Expected nil listener when session is closed")
}
}

7
datagram/log.go Normal file
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package datagram
import (
"github.com/go-i2p/logger"
)
var log = logger.GetGoI2PLogger()

150
datagram/packetconn.go Normal file
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package datagram
import (
"net"
"time"
"github.com/go-i2p/i2pkeys"
"github.com/samber/oops"
)
// ReadFrom reads a datagram from the connection
func (c *DatagramConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
c.mu.RLock()
if c.closed {
c.mu.RUnlock()
return 0, nil, oops.Errorf("connection is closed")
}
c.mu.RUnlock()
// Start receive loop if not already started
go c.reader.receiveLoop()
datagram, err := c.reader.ReceiveDatagram()
if err != nil {
return 0, nil, err
}
// Copy data to the provided buffer
n = copy(p, datagram.Data)
addr = &DatagramAddr{addr: datagram.Source}
return n, addr, nil
}
// WriteTo writes a datagram to the specified address
func (c *DatagramConn) WriteTo(p []byte, addr net.Addr) (n int, err error) {
c.mu.RLock()
if c.closed {
c.mu.RUnlock()
return 0, oops.Errorf("connection is closed")
}
c.mu.RUnlock()
// Convert address to I2P address
i2pAddr, ok := addr.(*DatagramAddr)
if !ok {
return 0, oops.Errorf("address must be a DatagramAddr")
}
err = c.writer.SendDatagram(p, i2pAddr.addr)
if err != nil {
return 0, err
}
return len(p), nil
}
// Close closes the datagram connection
func (c *DatagramConn) Close() error {
c.mu.Lock()
defer c.mu.Unlock()
if c.closed {
return nil
}
logger := log.WithField("session_id", c.session.ID())
logger.Debug("Closing DatagramConn")
c.closed = true
// Close reader and writer
if c.reader != nil {
c.reader.Close()
}
// Close the session
if err := c.session.Close(); err != nil {
logger.WithError(err).Error("Failed to close session")
return oops.Errorf("failed to close datagram connection: %w", err)
}
logger.Debug("Successfully closed DatagramConn")
return nil
}
// LocalAddr returns the local address
func (c *DatagramConn) LocalAddr() net.Addr {
return &DatagramAddr{addr: c.session.Addr()}
}
// SetDeadline sets the read and write deadlines
func (c *DatagramConn) SetDeadline(t time.Time) error {
if err := c.SetReadDeadline(t); err != nil {
return err
}
return c.SetWriteDeadline(t)
}
// SetReadDeadline sets the deadline for future ReadFrom calls
func (c *DatagramConn) SetReadDeadline(t time.Time) error {
// For datagrams, we handle timeouts differently
// This is a placeholder implementation
return nil
}
// SetWriteDeadline sets the deadline for future WriteTo calls
func (c *DatagramConn) SetWriteDeadline(t time.Time) error {
// Calculate timeout duration
if !t.IsZero() {
timeout := time.Until(t)
c.writer.SetTimeout(timeout)
}
return nil
}
// Read implements net.Conn by wrapping ReadFrom.
// It reads data into the provided byte slice and returns the number of bytes read.
// When reading, it also updates the remote address of the connection.
// Note: This is not a typical use case for datagrams, as they are connectionless.
// However, for compatibility with net.Conn, we implement it this way.
func (c *DatagramConn) Read(b []byte) (n int, err error) {
n, addr, err := c.ReadFrom(b)
c.remoteAddr = addr.(*i2pkeys.I2PAddr)
return n, err
}
// RemoteAddr returns the remote address of the connection.
// For datagram connections, this returns nil as there is no single remote address.
func (c *DatagramConn) RemoteAddr() net.Addr {
if c.remoteAddr != nil {
return &DatagramAddr{addr: *c.remoteAddr}
}
return nil
}
// Write implements net.Conn by wrapping WriteTo.
// It writes data to the remote address and returns the number of bytes written.
// It uses the remote address set by the last Read operation.
// If no remote address is set, it returns an error.
// Note: This is not a typical use case for datagrams, as they are connectionless.
// However, for compatibility with net.Conn, we implement it this way.
func (c *DatagramConn) Write(b []byte) (n int, err error) {
if c.remoteAddr == nil {
return 0, oops.Errorf("no remote address set, use WriteTo or Read first")
}
addr := &DatagramAddr{addr: *c.remoteAddr}
return c.WriteTo(b, addr)
}

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datagram/packetlistener.go Normal file
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package datagram
import (
"net"
"sync"
"github.com/samber/oops"
)
// DatagramListener implements net.DatagramListener for I2P datagram connections
type DatagramListener struct {
session *DatagramSession
reader *DatagramReader
acceptChan chan net.Conn
errorChan chan error
closeChan chan struct{}
closed bool
mu sync.RWMutex
}
// Accept waits for and returns the next packet connection to the listener
func (l *DatagramListener) Accept() (net.Conn, error) {
l.mu.RLock()
if l.closed {
l.mu.RUnlock()
return nil, oops.Errorf("listener is closed")
}
l.mu.RUnlock()
select {
case conn := <-l.acceptChan:
return conn, nil
case err := <-l.errorChan:
return nil, err
case <-l.closeChan:
return nil, oops.Errorf("listener is closed")
}
}
// Close closes the packet listener
func (l *DatagramListener) Close() error {
l.mu.Lock()
defer l.mu.Unlock()
if l.closed {
return nil
}
logger := log.WithField("session_id", l.session.ID())
logger.Debug("Closing PacketListener")
l.closed = true
close(l.closeChan)
// Close the reader
if l.reader != nil {
l.reader.Close()
}
logger.Debug("Successfully closed PacketListener")
return nil
}
// Addr returns the listener's network address
func (l *DatagramListener) Addr() net.Addr {
return &DatagramAddr{addr: l.session.Addr()}
}
// acceptLoop continuously accepts incoming packet connections
func (l *DatagramListener) acceptLoop() {
logger := log.WithField("session_id", l.session.ID())
logger.Debug("Starting packet accept loop")
for {
select {
case <-l.closeChan:
logger.Debug("Packet accept loop terminated - listener closed")
return
default:
conn, err := l.acceptPacketConnection()
if err != nil {
l.mu.RLock()
closed := l.closed
l.mu.RUnlock()
if !closed {
logger.WithError(err).Error("Failed to accept packet connection")
select {
case l.errorChan <- err:
case <-l.closeChan:
return
}
}
continue
}
select {
case l.acceptChan <- conn:
logger.Debug("Successfully accepted new packet connection")
case <-l.closeChan:
conn.Close()
return
}
}
}
}
// acceptPacketConnection creates a new packet connection for incoming datagrams
func (l *DatagramListener) acceptPacketConnection() (net.Conn, error) {
logger := log.WithField("session_id", l.session.ID())
logger.Debug("Creating new packet connection")
// For datagram sessions, we create a new DatagramConn that shares the session
// but has its own reader/writer for handling the specific connection
conn := &DatagramConn{
session: l.session,
reader: l.session.NewReader(),
writer: l.session.NewWriter(),
}
// Start the reader loop for this connection
go conn.reader.receiveLoop()
return conn, nil
}

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datagram/read.go Normal file
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package datagram
import (
"bufio"
"encoding/base64"
"strings"
"time"
"github.com/go-i2p/i2pkeys"
"github.com/samber/oops"
)
// ReceiveDatagram receives a datagram from any source
func (r *DatagramReader) ReceiveDatagram() (*Datagram, error) {
// Check if closed first, but don't rely on this check for safety
r.mu.RLock()
if r.closed {
r.mu.RUnlock()
return nil, oops.Errorf("reader is closed")
}
r.mu.RUnlock()
// Use select with closeChan to handle concurrent close operations safely
// The closeChan will be signaled when Close() is called, providing
// a reliable way to detect closure even if it happens during this function
select {
case datagram := <-r.recvChan:
return datagram, nil
case err := <-r.errorChan:
return nil, err
case <-r.closeChan:
// This case handles both initial closure check and concurrent closure
return nil, oops.Errorf("reader is closed")
}
}
func (r *DatagramReader) Close() error {
r.mu.Lock()
defer r.mu.Unlock()
if r.closed {
return nil
}
logger := log.WithField("session_id", r.session.ID())
logger.Debug("Closing DatagramReader")
r.closed = true
// Signal termination to receiveLoop and wait for it to exit
close(r.closeChan)
// Give receiveLoop time to detect the close signal and exit
// before closing the channels it might be writing to
time.Sleep(10 * time.Millisecond)
// Now safe to close the receiver channels
close(r.recvChan)
close(r.errorChan)
logger.Debug("Successfully closed DatagramReader")
return nil
}
// receiveLoop continuously receives incoming datagrams
func (r *DatagramReader) receiveLoop() {
logger := log.WithField("session_id", r.session.ID())
logger.Debug("Starting receive loop")
for {
// Check for closure in a non-blocking way first
select {
case <-r.closeChan:
logger.Debug("Receive loop terminated - reader closed")
return
default:
}
// Now perform the blocking read operation
datagram, err := r.receiveDatagram()
if err != nil {
// Use atomic check and send pattern to avoid race
select {
case r.errorChan <- err:
logger.WithError(err).Error("Failed to receive datagram")
case <-r.closeChan:
// Reader was closed during error handling
return
}
continue
}
// Send the datagram or handle closure atomically
select {
case r.recvChan <- datagram:
logger.Debug("Successfully received datagram")
case <-r.closeChan:
// Reader was closed during datagram send
return
}
}
}
// receiveDatagram handles the low-level datagram reception
func (r *DatagramReader) receiveDatagram() (*Datagram, error) {
logger := log.WithField("session_id", r.session.ID())
// Read from the session connection for incoming datagrams
buf := make([]byte, 4096)
n, err := r.session.Read(buf)
if err != nil {
return nil, oops.Errorf("failed to read from session: %w", err)
}
response := string(buf[:n])
logger.WithField("response", response).Debug("Received datagram data")
// Parse the DATAGRAM RECEIVED response
scanner := bufio.NewScanner(strings.NewReader(response))
scanner.Split(bufio.ScanWords)
var source, data string
for scanner.Scan() {
word := scanner.Text()
switch {
case word == "DATAGRAM":
continue
case word == "RECEIVED":
continue
case strings.HasPrefix(word, "DESTINATION="):
source = word[12:]
case strings.HasPrefix(word, "SIZE="):
continue // We'll get the actual data size from the payload
default:
// Remaining data is the base64-encoded payload
if data == "" {
data = word
} else {
data += " " + word
}
}
}
if source == "" {
return nil, oops.Errorf("no source in datagram")
}
if data == "" {
return nil, oops.Errorf("no data in datagram")
}
// Parse the source destination
sourceAddr, err := i2pkeys.NewI2PAddrFromString(source)
if err != nil {
return nil, oops.Errorf("failed to parse source address: %w", err)
}
// Decode the base64 data
decodedData, err := base64.StdEncoding.DecodeString(data)
if err != nil {
return nil, oops.Errorf("failed to decode datagram data: %w", err)
}
// Create the datagram
datagram := &Datagram{
Data: decodedData,
Source: sourceAddr,
Local: r.session.Addr(),
}
return datagram, nil
}

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datagram/session.go Normal file
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package datagram
import (
"net"
"github.com/go-i2p/go-sam-go/common"
"github.com/go-i2p/i2pkeys"
"github.com/samber/oops"
"github.com/sirupsen/logrus"
)
// NewDatagramSession creates a new datagram session
func NewDatagramSession(sam *common.SAM, id string, keys i2pkeys.I2PKeys, options []string) (*DatagramSession, error) {
logger := log.WithFields(logrus.Fields{
"id": id,
"options": options,
})
logger.Debug("Creating new DatagramSession")
// Create the base session using the common package
session, err := sam.NewGenericSession("DATAGRAM", id, keys, options)
if err != nil {
logger.WithError(err).Error("Failed to create generic session")
return nil, oops.Errorf("failed to create datagram session: %w", err)
}
baseSession, ok := session.(*common.BaseSession)
if !ok {
logger.Error("Session is not a BaseSession")
session.Close()
return nil, oops.Errorf("invalid session type")
}
ds := &DatagramSession{
BaseSession: baseSession,
sam: sam,
options: options,
}
logger.Debug("Successfully created DatagramSession")
return ds, nil
}
// NewReader creates a DatagramReader for receiving datagrams
func (s *DatagramSession) NewReader() *DatagramReader {
return &DatagramReader{
session: s,
recvChan: make(chan *Datagram, 10), // Buffer for incoming datagrams
errorChan: make(chan error, 1),
closeChan: make(chan struct{}),
}
}
// NewWriter creates a DatagramWriter for sending datagrams
func (s *DatagramSession) NewWriter() *DatagramWriter {
return &DatagramWriter{
session: s,
timeout: 30, // Default timeout in seconds
}
}
// PacketConn returns a net.PacketConn interface for this session
func (s *DatagramSession) PacketConn() net.PacketConn {
return &DatagramConn{
session: s,
reader: s.NewReader(),
writer: s.NewWriter(),
}
}
// SendDatagram sends a datagram to the specified destination
func (s *DatagramSession) SendDatagram(data []byte, dest i2pkeys.I2PAddr) error {
return s.NewWriter().SendDatagram(data, dest)
}
// ReceiveDatagram receives a datagram from any source
func (s *DatagramSession) ReceiveDatagram() (*Datagram, error) {
reader := s.NewReader()
// Start the receive loop
go reader.receiveLoop()
return reader.ReceiveDatagram()
}
// Close closes the datagram session and all associated resources
func (s *DatagramSession) Close() error {
s.mu.Lock()
defer s.mu.Unlock()
if s.closed {
return nil
}
logger := log.WithField("id", s.ID())
logger.Debug("Closing DatagramSession")
s.closed = true
// Close the base session
if err := s.BaseSession.Close(); err != nil {
logger.WithError(err).Error("Failed to close base session")
return oops.Errorf("failed to close datagram session: %w", err)
}
logger.Debug("Successfully closed DatagramSession")
return nil
}
// Addr returns the I2P address of this session
func (s *DatagramSession) Addr() i2pkeys.I2PAddr {
return s.Keys().Addr()
}
// Network returns the network type
func (a *DatagramAddr) Network() string {
return "i2p-datagram"
}
// String returns the string representation of the address
func (a *DatagramAddr) String() string {
return a.addr.Base32()
}

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datagram/session_test.go Normal file
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package datagram
import (
"testing"
"time"
"github.com/go-i2p/go-sam-go/common"
"github.com/go-i2p/i2pkeys"
)
const testSAMAddr = "127.0.0.1:7656"
func setupTestSAM(t *testing.T) (*common.SAM, i2pkeys.I2PKeys) {
t.Helper()
sam, err := common.NewSAM(testSAMAddr)
if err != nil {
t.Fatalf("Failed to create SAM connection: %v", err)
}
keys, err := sam.NewKeys()
if err != nil {
sam.Close()
t.Fatalf("Failed to generate keys: %v", err)
}
return sam, keys
}
func TestNewDatagramSession(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
tests := []struct {
name string
id string
options []string
wantErr bool
}{
{
name: "basic session creation",
id: "test_datagram_session",
options: nil,
wantErr: false,
},
{
name: "session with options",
id: "test_datagram_with_opts",
options: []string{"inbound.length=1", "outbound.length=1"},
wantErr: false,
},
{
name: "session with small tunnel config",
id: "test_datagram_small",
options: []string{
"inbound.length=0",
"outbound.length=0",
"inbound.lengthVariance=0",
"outbound.lengthVariance=0",
"inbound.quantity=1",
"outbound.quantity=1",
},
wantErr: false,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
sam, keys := setupTestSAM(t)
defer sam.Close()
session, err := NewDatagramSession(sam, tt.id, keys, tt.options)
if (err != nil) != tt.wantErr {
t.Errorf("NewDatagramSession() error = %v, wantErr %v", err, tt.wantErr)
return
}
if err == nil {
// Verify session properties
if session.ID() != tt.id {
t.Errorf("Session ID = %v, want %v", session.ID(), tt.id)
}
if session.Keys().Addr().Base32() != keys.Addr().Base32() {
t.Error("Session keys don't match provided keys")
}
addr := session.Addr()
if addr.Base32() == "" {
t.Error("Session address is empty")
}
// Clean up
if err := session.Close(); err != nil {
t.Errorf("Failed to close session: %v", err)
}
}
})
}
}
func TestDatagramSession_Close(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
sam, keys := setupTestSAM(t)
defer sam.Close()
session, err := NewDatagramSession(sam, "test_close", keys, nil)
if err != nil {
t.Fatalf("Failed to create session: %v", err)
}
// Close the session
err = session.Close()
if err != nil {
t.Errorf("Close() error = %v", err)
}
// Closing again should not error
err = session.Close()
if err != nil {
t.Errorf("Second Close() error = %v", err)
}
}
func TestDatagramSession_Addr(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
sam, keys := setupTestSAM(t)
defer sam.Close()
session, err := NewDatagramSession(sam, "test_addr", keys, nil)
if err != nil {
t.Fatalf("Failed to create session: %v", err)
}
defer session.Close()
addr := session.Addr()
expectedAddr := keys.Addr()
if addr.Base32() != expectedAddr.Base32() {
t.Errorf("Addr() = %v, want %v", addr.Base32(), expectedAddr.Base32())
}
}
func TestDatagramSession_NewReader(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
sam, keys := setupTestSAM(t)
defer sam.Close()
session, err := NewDatagramSession(sam, "test_reader", keys, nil)
if err != nil {
t.Fatalf("Failed to create session: %v", err)
}
defer session.Close()
reader := session.NewReader()
if reader == nil {
t.Error("NewReader() returned nil")
}
if reader.session != session {
t.Error("Reader session reference is incorrect")
}
// Verify channels are initialized
if reader.recvChan == nil {
t.Error("Reader recvChan is nil")
}
if reader.errorChan == nil {
t.Error("Reader errorChan is nil")
}
if reader.closeChan == nil {
t.Error("Reader closeChan is nil")
}
}
func TestDatagramSession_NewWriter(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
sam, keys := setupTestSAM(t)
defer sam.Close()
session, err := NewDatagramSession(sam, "test_writer", keys, nil)
if err != nil {
t.Fatalf("Failed to create session: %v", err)
}
defer session.Close()
writer := session.NewWriter()
if writer == nil {
t.Error("NewWriter() returned nil")
}
if writer.session != session {
t.Error("Writer session reference is incorrect")
}
if writer.timeout != 30 {
t.Errorf("Writer timeout = %v, want 30", writer.timeout)
}
}
func TestDatagramSession_PacketConn(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
sam, keys := setupTestSAM(t)
defer sam.Close()
session, err := NewDatagramSession(sam, "test_packetconn", keys, nil)
if err != nil {
t.Fatalf("Failed to create session: %v", err)
}
defer session.Close()
conn := session.PacketConn()
if conn == nil {
t.Error("PacketConn() returned nil")
}
datagramConn, ok := conn.(*DatagramConn)
if !ok {
t.Error("PacketConn() did not return a DatagramConn")
}
if datagramConn.session != session {
t.Error("DatagramConn session reference is incorrect")
}
if datagramConn.reader == nil {
t.Error("DatagramConn reader is nil")
}
if datagramConn.writer == nil {
t.Error("DatagramConn writer is nil")
}
}
func TestDatagramSession_ConcurrentOperations(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
sam, keys := setupTestSAM(t)
defer sam.Close()
session, err := NewDatagramSession(sam, "test_concurrent", keys, nil)
if err != nil {
t.Fatalf("Failed to create session: %v", err)
}
defer session.Close()
// Test concurrent reader creation
done := make(chan bool, 10)
for i := 0; i < 10; i++ {
go func() {
reader := session.NewReader()
if reader == nil {
t.Error("NewReader returned nil")
}
done <- true
}()
}
// Test concurrent writer creation
for i := 0; i < 10; i++ {
go func() {
writer := session.NewWriter()
if writer == nil {
t.Error("NewWriter returned nil")
}
done <- true
}()
}
// Wait for all goroutines
timeout := time.After(5 * time.Second)
for i := 0; i < 20; i++ {
select {
case <-done:
// OK
case <-timeout:
t.Fatal("Timeout waiting for concurrent operations")
}
}
}
func TestDatagramAddr_Network(t *testing.T) {
addr := &DatagramAddr{}
if addr.Network() != "i2p-datagram" {
t.Errorf("Network() = %v, want i2p-datagram", addr.Network())
}
}
func TestDatagramAddr_String(t *testing.T) {
if testing.Short() {
t.Skip("Skipping integration test in short mode")
}
sam, keys := setupTestSAM(t)
defer sam.Close()
addr := &DatagramAddr{addr: keys.Addr()}
expected := keys.Addr().Base32()
if addr.String() != expected {
t.Errorf("String() = %v, want %v", addr.String(), expected)
}
}

56
datagram/types.go Normal file
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package datagram
import (
"sync"
"time"
"github.com/go-i2p/go-sam-go/common"
"github.com/go-i2p/i2pkeys"
)
// DatagramSession represents a datagram session that can send and receive datagrams
type DatagramSession struct {
*common.BaseSession
sam *common.SAM
options []string
mu sync.RWMutex
closed bool
}
// DatagramReader handles incoming datagram reception
type DatagramReader struct {
session *DatagramSession
recvChan chan *Datagram
errorChan chan error
closeChan chan struct{}
closed bool
mu sync.RWMutex
}
// DatagramWriter handles outgoing datagram transmission
type DatagramWriter struct {
session *DatagramSession
timeout time.Duration
}
// Datagram represents an I2P datagram message
type Datagram struct {
Data []byte
Source i2pkeys.I2PAddr
Local i2pkeys.I2PAddr
}
// DatagramAddr implements net.Addr for I2P datagram addresses
type DatagramAddr struct {
addr i2pkeys.I2PAddr
}
// DatagramConn implements net.PacketConn for I2P datagrams
type DatagramConn struct {
session *DatagramSession
reader *DatagramReader
writer *DatagramWriter
remoteAddr *i2pkeys.I2PAddr
mu sync.RWMutex
closed bool
}

14
datagram/types_test.go Normal file
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package datagram
import (
"net"
"github.com/go-i2p/go-sam-go/common"
)
var (
ds common.Session = &DatagramSession{}
dl net.Listener = &DatagramListener{}
dc net.PacketConn = &DatagramConn{}
dcc net.Conn = &DatagramConn{}
)

96
datagram/write.go Normal file
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package datagram
import (
"encoding/base64"
"fmt"
"strings"
"time"
"github.com/go-i2p/i2pkeys"
"github.com/samber/oops"
"github.com/sirupsen/logrus"
)
// SetTimeout sets the timeout for datagram operations
func (w *DatagramWriter) SetTimeout(timeout time.Duration) *DatagramWriter {
w.timeout = timeout
return w
}
// SendDatagram sends a datagram to the specified destination
func (w *DatagramWriter) SendDatagram(data []byte, dest i2pkeys.I2PAddr) error {
w.session.mu.RLock()
if w.session.closed {
w.session.mu.RUnlock()
return oops.Errorf("session is closed")
}
w.session.mu.RUnlock()
logger := log.WithFields(logrus.Fields{
"session_id": w.session.ID(),
"destination": dest.Base32(),
"size": len(data),
})
logger.Debug("Sending datagram")
// Encode the data as base64
encodedData := base64.StdEncoding.EncodeToString(data)
// Create the DATAGRAM SEND command
sendCmd := fmt.Sprintf("DATAGRAM SEND ID=%s DESTINATION=%s SIZE=%d\n%s\n",
w.session.ID(), dest.Base64(), len(data), encodedData)
logger.WithField("command", strings.Split(sendCmd, "\n")[0]).Debug("Sending DATAGRAM SEND")
// Send the command
_, err := w.session.Write([]byte(sendCmd))
if err != nil {
logger.WithError(err).Error("Failed to send datagram")
return oops.Errorf("failed to send datagram: %w", err)
}
// Read the response
buf := make([]byte, 1024)
n, err := w.session.Read(buf)
if err != nil {
logger.WithError(err).Error("Failed to read send response")
return oops.Errorf("failed to read send response: %w", err)
}
response := string(buf[:n])
logger.WithField("response", response).Debug("Received send response")
// Parse the response
if err := w.parseSendResponse(response); err != nil {
return err
}
logger.Debug("Successfully sent datagram")
return nil
}
// parseSendResponse parses the DATAGRAM STATUS response
func (w *DatagramWriter) parseSendResponse(response string) error {
if strings.Contains(response, "RESULT=OK") {
return nil
}
switch {
case strings.Contains(response, "RESULT=CANT_REACH_PEER"):
return oops.Errorf("cannot reach peer")
case strings.Contains(response, "RESULT=I2P_ERROR"):
return oops.Errorf("I2P internal error")
case strings.Contains(response, "RESULT=INVALID_KEY"):
return oops.Errorf("invalid destination key")
case strings.Contains(response, "RESULT=INVALID_ID"):
return oops.Errorf("invalid session ID")
case strings.Contains(response, "RESULT=TIMEOUT"):
return oops.Errorf("send timeout")
default:
if strings.HasPrefix(response, "DATAGRAM STATUS RESULT=") {
result := strings.TrimSpace(response[23:])
return oops.Errorf("send failed: %s", result)
}
return oops.Errorf("unexpected response format: %s", response)
}
}

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stream/README.md Normal file
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# go-sam-go/stream
High-level streaming library for reliable TCP-like connections over I2P using the SAMv3 protocol.
## Installation
Install using Go modules with the package path `github.com/go-i2p/go-sam-go/stream`.
## Usage
The package provides TCP-like streaming connections over I2P networks. [`StreamSession`](stream/types.go) manages the connection lifecycle, [`StreamListener`](stream/types.go) handles incoming connections, and [`StreamConn`](stream/types.go) implements the standard `net.Conn` interface for seamless integration with existing Go networking code.
Create sessions using [`NewStreamSession`](stream/session.go), establish listeners with [`Listen()`](stream/session.go), and dial outbound connections using [`Dial()`](stream/session.go) or [`DialI2P()`](stream/session.go). The implementation supports context-based timeouts, concurrent operations, and automatic connection management.
Key features include full `net.Listener` and `net.Conn` compatibility, I2P address resolution, configurable tunnel parameters, and comprehensive error handling with proper resource cleanup.
## Dependencies
- github.com/go-i2p/go-sam-go/common - Core SAM protocol implementation
- github.com/go-i2p/i2pkeys - I2P cryptographic key handling
- github.com/go-i2p/logger - Logging functionality
- github.com/sirupsen/logrus - Structured logging
- github.com/samber/oops - Enhanced error handling