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ipc bridge does 3way handshake to sync new connections; a few other minor fixes to the flow

pull/273/head
Dan Ballard 3 months ago
parent
commit
6a169472e7
4 changed files with 407 additions and 50 deletions
  1. 72
    0
      event/bridge/infinite_chan.go
  2. 105
    0
      event/bridge/infinite_queue.go
  3. 156
    50
      event/bridge/pipeBridge.go
  4. 74
    0
      event/bridge/pipeBridge_test.go

+ 72
- 0
event/bridge/infinite_chan.go View File

@@ -0,0 +1,72 @@
package bridge

/* Todo: When go generics ships, refactor this and event.infiniteChannel into one */

// InfiniteChannel implements the Channel interface with an infinite buffer between the input and the output.
type InfiniteChannel struct {
input, output chan interface{}
length chan int
buffer *InfiniteQueue
}

func newInfiniteChannel() *InfiniteChannel {
ch := &InfiniteChannel{
input: make(chan interface{}),
output: make(chan interface{}),
length: make(chan int),
buffer: newInfiniteQueue(),
}
go ch.infiniteBuffer()
return ch
}

// In returns the input channel
func (ch *InfiniteChannel) In() chan<- interface{} {
return ch.input
}

// Out returns the output channel
func (ch *InfiniteChannel) Out() <-chan interface{} {
return ch.output
}

// Len returns the length of items in queue
func (ch *InfiniteChannel) Len() int {
return <-ch.length
}

// Close closes the InfiniteChanel
func (ch *InfiniteChannel) Close() {
close(ch.input)
}

func (ch *InfiniteChannel) infiniteBuffer() {
var input, output chan interface{}
var next interface{}
input = ch.input

for input != nil || output != nil {
select {
case elem, open := <-input:
if open {
ch.buffer.Add(elem)
} else {
input = nil
}
case output <- next:
ch.buffer.Remove()
case ch.length <- ch.buffer.Length():
}

if ch.buffer.Length() > 0 {
output = ch.output
next = ch.buffer.Peek()
} else {
output = nil
next = nil
}
}

close(ch.output)
close(ch.length)
}

+ 105
- 0
event/bridge/infinite_queue.go View File

@@ -0,0 +1,105 @@
package bridge

/* Todo: When go generics ships, refactor this and event.infinitQueue channel into one */

/*
Package queue provides a fast, ring-buffer queue based on the version suggested by Dariusz Górecki.
Using this instead of other, simpler, queue implementations (slice+append or linked list) provides
substantial memory and time benefits, and fewer GC pauses.

The queue implemented here is as fast as it is for an additional reason: it is *not* thread-safe.
*/

// minQueueLen is smallest capacity that queue may have.
// Must be power of 2 for bitwise modulus: x % n == x & (n - 1).
const minQueueLen = 16

// InfiniteQueue represents a single instance of the queue data structure.
type InfiniteQueue struct {
buf []interface{}
head, tail, count int
}

// New constructs and returns a new Queue.
func newInfiniteQueue() *InfiniteQueue {
return &InfiniteQueue{
buf: make([]interface{}, minQueueLen),
}
}

// Length returns the number of elements currently stored in the queue.
func (q *InfiniteQueue) Length() int {
return q.count
}

// resizes the queue to fit exactly twice its current contents
// this can result in shrinking if the queue is less than half-full
func (q *InfiniteQueue) resize() {
newBuf := make([]interface{}, q.count<<1)

if q.tail > q.head {
copy(newBuf, q.buf[q.head:q.tail])
} else {
n := copy(newBuf, q.buf[q.head:])
copy(newBuf[n:], q.buf[:q.tail])
}

q.head = 0
q.tail = q.count
q.buf = newBuf
}

// Add puts an element on the end of the queue.
func (q *InfiniteQueue) Add(elem interface{}) {
if q.count == len(q.buf) {
q.resize()
}

q.buf[q.tail] = elem
// bitwise modulus
q.tail = (q.tail + 1) & (len(q.buf) - 1)
q.count++
}

// Peek returns the element at the head of the queue. This call panics
// if the queue is empty.
func (q *InfiniteQueue) Peek() interface{} {
if q.count <= 0 {
panic("queue: Peek() called on empty queue")
}
return q.buf[q.head]
}

// Get returns the element at index i in the queue. If the index is
// invalid, the call will panic. This method accepts both positive and
// negative index values. Index 0 refers to the first element, and
// index -1 refers to the last.
func (q *InfiniteQueue) Get(i int) interface{} {
// If indexing backwards, convert to positive index.
if i < 0 {
i += q.count
}
if i < 0 || i >= q.count {
panic("queue: Get() called with index out of range")
}
// bitwise modulus
return q.buf[(q.head+i)&(len(q.buf)-1)]
}

// Remove removes and returns the element from the front of the queue. If the
// queue is empty, the call will panic.
func (q *InfiniteQueue) Remove() interface{} {
if q.count <= 0 {
panic("queue: Remove() called on empty queue")
}
ret := q.buf[q.head]
q.buf[q.head] = nil
// bitwise modulus
q.head = (q.head + 1) & (len(q.buf) - 1)
q.count--
// Resize down if buffer 1/4 full.
if len(q.buf) > minQueueLen && (q.count<<2) == len(q.buf) {
q.resize()
}
return ret
}

+ 156
- 50
event/bridge/pipeBridge.go View File

@@ -8,6 +8,7 @@ import (
"encoding/binary"
"git.openprivacy.ca/openprivacy/libricochet-go/log"
"syscall"
"time"

"cwtch.im/cwtch/event"
"encoding/json"
@@ -21,13 +22,22 @@ import (

const maxBufferSize = 1000

const serviceName = "service"
const clientName = "client"

const syn = "SYN"
const synack = "SYNACK"
const ack = "ACK"

type pipeBridge struct {
infile, outfile string
in, out *os.File
read, write chan event.IPCMessage
read chan event.IPCMessage
write *InfiniteChannel
closedChan chan bool
state connections.ConnectionState
lock sync.Mutex
threeShake func () bool

// For logging / debugging purposes
name string
@@ -38,7 +48,7 @@ func newPipeBridge(inFilename, outFilename string) *pipeBridge {
syscall.Mkfifo(outFilename, 0600)
pb := &pipeBridge{infile: inFilename, outfile: outFilename, state: connections.DISCONNECTED}
pb.read = make(chan event.IPCMessage, maxBufferSize)
pb.write = make(chan event.IPCMessage, maxBufferSize)
pb.write = newInfiniteChannel() //make(chan event.IPCMessage, maxBufferSize)
return pb
}

@@ -46,7 +56,8 @@ func newPipeBridge(inFilename, outFilename string) *pipeBridge {
func NewPipeBridgeClient(inFilename, outFilename string) event.IPCBridge {
log.Debugf("Making new PipeBridge Client...\n")
pb := newPipeBridge(inFilename, outFilename)
pb.name = "client"
pb.name = clientName
pb.threeShake = pb.threeShakeClient
go pb.connectionManager()

return pb
@@ -56,7 +67,8 @@ func NewPipeBridgeClient(inFilename, outFilename string) event.IPCBridge {
func NewPipeBridgeService(inFilename, outFilename string) event.IPCBridge {
log.Debugf("Making new PipeBridge Service...\n")
pb := newPipeBridge(inFilename, outFilename)
pb.name = "service"
pb.name = serviceName
pb.threeShake = pb.threeShakeService

go pb.connectionManager()

@@ -92,9 +104,74 @@ func (pb *pipeBridge) connectionManager() {

}

// threeShake performs a 3way handshake sync up
func (pb *pipeBridge) threeShakeService() bool {
synacked := false

for {
resp, err := pb.readString()
if err != nil {
return false
}

if string(resp) == syn {
if !synacked {
err = pb.writeString([]byte(synack))
if err != nil {
return false
}
synacked = true
}
} else if string(resp) == ack {
return true
}
}
}

func (pb *pipeBridge) synLoop(stop chan bool) {
delay := time.Duration(0)
for {
select {
case <-time.After(delay):
err := pb.writeString([]byte(syn))
if err != nil {
return
}
delay = time.Second
case <- stop:
return
}
}
}

func (pb *pipeBridge) threeShakeClient() bool {
stop := make(chan bool)
go pb.synLoop(stop)
for {
resp, err := pb.readString()
if err != nil {
return false
}

if string(resp) == synack {
stop <- true
err := pb.writeString([]byte(ack))
if err != nil {
return false
}
return true
}
}
}

func (pb *pipeBridge) handleConns() {

// auth?
if !pb.threeShake() {
pb.state = connections.FAILED
pb.closeReset()
return
}

pb.state = connections.AUTHENTICATED

pb.closedChan = make(chan bool, 5)
@@ -116,10 +193,13 @@ func (pb *pipeBridge) handleConns() {
func (pb *pipeBridge) closeReset() {
pb.in.Close()
pb.out.Close()
close(pb.write)
close(pb.read)
pb.read = make(chan event.IPCMessage, maxBufferSize)
pb.write = make(chan event.IPCMessage, maxBufferSize)
pb.write.Close()

if pb.state != connections.KILLED {
pb.read = make(chan event.IPCMessage, maxBufferSize)
pb.write = newInfiniteChannel()
}
}

func (pb *pipeBridge) handleWrite() {
@@ -128,7 +208,12 @@ func (pb *pipeBridge) handleWrite() {

for {
select {
case message := <-pb.write:
case messageInf := <-pb.write.output:
if messageInf == nil {
pb.closedChan <- true
return
}
message := messageInf.(event.IPCMessage)
if message.Message.EventType == event.EncryptedGroupMessage || message.Message.EventType == event.SendMessageToGroup || message.Message.EventType == event.NewMessageFromGroup {
log.Debugf("handleWrite <- message: %v %v ...\n", message.Dest, message.Message.EventType)
} else {
@@ -141,18 +226,10 @@ func (pb *pipeBridge) handleWrite() {
}

messageJSON, _ := json.Marshal(encMessage)
size := make([]byte, 2)
binary.LittleEndian.PutUint16(size, uint16(len(messageJSON)))
pb.out.Write(size)

for pos := 0; pos < len(messageJSON); {
n, err := pb.out.Write(messageJSON)
if err != nil {
log.Errorf("Writing out on pipeBridge: %v\n", err)
pb.closedChan <- true
return
}
pos += n
err := pb.writeString(messageJSON)
if err != nil {
pb.closedChan <- true
return
}
} else {
return
@@ -165,37 +242,21 @@ func (pb *pipeBridge) handleRead() {
log.Debugf("handleRead() %v\n", pb.name)
defer log.Debugf("exiting handleRead() %v", pb.name)

var n int
size := make([]byte, 2)
var err error
for {
log.Debugf("Waiting to handleRead()...\n")
n, err = pb.in.Read(size)
if err != nil || n != 2 {
log.Errorf("Could not read len int from stream: %v\n", err)

buffer, err := pb.readString()
if err != nil {
pb.closedChan <- true
return
}

n = int(binary.LittleEndian.Uint16(size))
pos := 0
buffer := make([]byte, n)
for n > 0 {
m, err := pb.in.Read(buffer[pos:])
if err != nil {
log.Errorf("Reading into buffer from pipe: %v\n", err)
pb.closedChan <- true
return
}
n -= m
pos += m
}

var message event.IPCMessage
err = json.Unmarshal(buffer, &message)
if err != nil {
log.Errorf("Read error: %v --value: %v", err, message)
continue // signal error?
log.Errorf("Read error: '%v', value: '%v'", err, buffer)
pb.closedChan <- true
return // probably new connection trying to initialize
}
for k, v := range message.Message.Data {
val, _ := base64.StdEncoding.DecodeString(v)
@@ -213,12 +274,15 @@ func (pb *pipeBridge) handleRead() {

func (pb *pipeBridge) Read() (*event.IPCMessage, bool) {
log.Debugf("Read() %v...\n", pb.name)

message := <-pb.read
if message.Message.EventType == event.EncryptedGroupMessage || message.Message.EventType == event.SendMessageToGroup || message.Message.EventType == event.NewMessageFromGroup {
log.Debugf("Read %v: %v %v ...\n", pb.name, message.Dest, message.Message.EventType)
} else {
log.Debugf("Read %v: %v\n", pb.name, message)
var ok = false
var message event.IPCMessage
for !ok && pb.state != connections.KILLED {
message, ok = <-pb.read
if message.Message.EventType == event.EncryptedGroupMessage || message.Message.EventType == event.SendMessageToGroup || message.Message.EventType == event.NewMessageFromGroup {
log.Debugf("Read %v: %v %v ...\n", pb.name, message.Dest, message.Message.EventType)
} else {
log.Debugf("Read %v: %v\n", pb.name, message)
}
}
return &message, pb.state != connections.KILLED
}
@@ -229,7 +293,7 @@ func (pb *pipeBridge) Write(message *event.IPCMessage) {
} else {
log.Debugf("Write %v: %v\n", pb.name, message)
}
pb.write <- *message
pb.write.input <- *message
log.Debugf("Wrote\n")
}

@@ -239,3 +303,45 @@ func (pb *pipeBridge) Shutdown() {
pb.closedChan <- true
log.Debugf("Done Shutdown for %v\n", pb.name)
}

func (pb *pipeBridge) writeString(message []byte) error {
size := make([]byte, 2)
binary.LittleEndian.PutUint16(size, uint16(len(message)))
pb.out.Write(size)

for pos := 0; pos < len(message); {
n, err := pb.out.Write(message[pos:])
if err != nil {
log.Errorf("Writing out on pipeBridge: %v\n", err)
return err
}
pos += n
}
return nil
}

func (pb *pipeBridge) readString() ([]byte, error) {
var n int
size := make([]byte, 2)
var err error

n, err = pb.in.Read(size)
if err != nil || n != 2 {
log.Errorf("Could not read len int from stream: %v\n", err)
return nil, err
}

n = int(binary.LittleEndian.Uint16(size))
pos := 0
buffer := make([]byte, n)
for n > 0 {
m, err := pb.in.Read(buffer[pos:])
if err != nil {
log.Errorf("Reading into buffer from pipe: %v\n", err)
return nil, err
}
n -= m
pos += m
}
return buffer, nil
}

+ 74
- 0
event/bridge/pipeBridge_test.go View File

@@ -2,7 +2,10 @@ package bridge

import (
"cwtch.im/cwtch/event"
"git.openprivacy.ca/openprivacy/libricochet-go/log"
"os"
"testing"
"time"
)

var (
@@ -44,6 +47,8 @@ func serviceHelper(t *testing.T, in, out string, messageOrig *event.IPCMessage,
}

func TestPipeBridge(t *testing.T) {
os.Remove(servicePipe)
os.Remove(clientPipe)

messageOrig := &event.IPCMessage{Dest: "ABC", Message: event.NewEventList(event.NewPeer, event.Identity, "It is I")}
serviceDone := make(chan bool)
@@ -55,3 +60,72 @@ func TestPipeBridge(t *testing.T) {
<-serviceDone
<-clientDone
}

func restartingClient(t *testing.T, in, out string, done chan bool) {
client := NewPipeBridgeClient(in, out)

message1 := &event.IPCMessage{Dest: "ABC", Message: event.NewEventList(event.NewPeer)}
log.Infoln("client writing message 1")
client.Write(message1)

time.Sleep(100 * time.Millisecond)
log.Infoln("client shutdown")
client.Shutdown()

log.Infoln("client new client")
client = NewPipeBridgeClient(in, out)
message2 := &event.IPCMessage{Dest: "ABC", Message: event.NewEventList(event.DeleteContact)}
log.Infoln("client2 write message2")
client.Write(message2)

done <- true
}

func stableService(t *testing.T, in, out string, done chan bool) {
service := NewPipeBridgeService(in, out)

log.Infoln("service wait read 1")
message1, ok := service.Read()
log.Infof("service read 1 %v ok:%v\n", message1, ok)
if !ok {
t.Errorf("Reading from client IPCBridge 1st time failed")
done <- true
return
}
if message1.Message.EventType != event.NewPeer {
t.Errorf("Wrong message recieved, expected NewPeer\n")
done <- true
return
}

log.Infoln("service wait read 2")
message2, ok := service.Read()
log.Infof("service read 2 got %v ok:%v\n", message2, ok)
if !ok {
t.Errorf("Reading from client IPCBridge 2nd time failed")
done <- true
return
}
if message2.Message.EventType != event.DeleteContact {
t.Errorf("Wrong message recieved, expected DeleteContact, got %v\n", message2)
done <- true
return
}

done <- true
}

func TestReconnect(t *testing.T) {
log.Infoln("TestReconnect")
os.Remove(servicePipe)
os.Remove(clientPipe)

serviceDone := make(chan bool)
clientDone := make(chan bool)

go restartingClient(t, clientPipe, servicePipe, clientDone)
go stableService(t, servicePipe, clientPipe, serviceDone)

<-serviceDone
<-clientDone
}

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