Merge pull request #207 from getlantern/nelson/bump-quic-go

Bump to quic-go 0.40

README.md

@@ -50,7 +50,7 @@ Instructions last updated March 29, 2023. If something's not working and it's be
 
 5. Build the browser widget: `cd cmd && ./build_web.sh`
 
-6. Start Freddie: `cd freddie && PORT=9000 go run freddie.go`
+6. Start Freddie: `cd freddie/cmd && PORT=9000 go run main.go`
 
 7. Start the egress server: `cd egress/cmd && PORT=8000 go run egress.go`
 

clientcore/quic.go

@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"net/url"
 	"sync"
+	"time"
 
 	"github.com/quic-go/quic-go"
 
@@ -41,61 +42,72 @@ type QUICLayerOptions struct {
 func NewQUICLayer(bfconn *BroflakeConn, qopt *QUICLayerOptions) (*QUICLayer, error) {
 	q := &QUICLayer{
 		bfconn: bfconn,
+		t:      &quic.Transport{Conn: bfconn},
 		tlsConfig: &tls.Config{
 			ServerName:         qopt.ServerName,
 			InsecureSkipVerify: qopt.InsecureSkipVerify,
 			NextProtos:         []string{"broflake"},
 			RootCAs:            qopt.CA,
 		},
 		eventualConn: newEventualConn(),
+		dialTimeout:  8 * time.Second,
 	}
 
 	return q, nil
 }
 
 type QUICLayer struct {
 	bfconn       *BroflakeConn
+	t            *quic.Transport
 	tlsConfig    *tls.Config
 	eventualConn *eventualConn
 	mx           sync.RWMutex
 	ctx          context.Context
 	cancel       context.CancelFunc
+	dialTimeout  time.Duration
 }
 
 // DialAndMaintainQUICConnection attempts to create and maintain an e2e QUIC connection by dialing
 // the other end, detecting if that connection breaks, and redialing. Forever.
 func (c *QUICLayer) DialAndMaintainQUICConnection() {
 	c.ctx, c.cancel = context.WithCancel(context.Background())
 
-	go func() {
-		for {
-			var conn quic.Connection
-
-			// State 1 of 2: Keep dialing until we acquire a connection
-			for {
-				select {
-				case <-c.ctx.Done():
-					common.Debugf("Cancelling QUIC dialer!")
-					return
-				default:
-					// Do nothing
-				}
-
-				var err error
-				conn, err = quic.Dial(c.bfconn, common.DebugAddr("NELSON WUZ HERE"), "DEBUG", c.tlsConfig, &common.QUICCfg)
-				if err != nil {
-					common.Debugf("QUIC dial failed (%v), retrying...", err)
-					continue
-				}
-				break
+	// State 1 of 2: Keep dialing until we acquire a connection
+	for {
+		select {
+		case <-c.ctx.Done():
+			common.Debugf("Cancelling QUIC dialer!")
+			return
+		default:
+			// Do nothing
+		}
+
+		ctxDial, cancelDial := context.WithTimeout(context.Background(), c.dialTimeout)
+		connEstablished := make(chan quic.Connection)
+		connErr := make(chan error)
+
+		go func() {
+			defer cancelDial()
+			conn, err := c.t.Dial(ctxDial, common.DebugAddr("NELSON WUZ HERE"), c.tlsConfig, &common.QUICCfg)
+
+			if err != nil {
+				connErr <- err
+				return
 			}
 
+			connEstablished <- conn
+		}()
+
+		select {
+		case err := <-connErr:
+			common.Debugf("QUIC dial failed (%v), retrying...", err)
+		case conn := <-connEstablished:
 			c.mx.Lock()
 			c.eventualConn.set(conn)
 			c.mx.Unlock()
 			common.Debug("QUIC connection established, ready to proxy!")
 
-			// State 2 of 2: Connection established, block until we detect a half open or a context cancellation
+			// State 2 of 2: Connection established, block until we detect a half open or a ctx cancel
 			_, err := conn.AcceptStream(c.ctx)
 			if err != nil {
 				common.Debugf("QUIC connection error (%v), closing!", err)
@@ -110,7 +122,7 @@ func (c *QUICLayer) DialAndMaintainQUICConnection() {
 			c.eventualConn = newEventualConn()
 			c.mx.Unlock()
 		}
-	}()
+	}
 }
 
 // Close a QUICLayer which was previously opened via a call to DialAndMaintainQUICConnection.

clientcore/user.go

@@ -10,6 +10,7 @@ import (
 	"context"
 	"net"
 	"sync"
+	"time"
 
 	"github.com/google/uuid"
 
@@ -18,20 +19,42 @@ import (
 
 type BroflakeConn struct {
 	net.PacketConn
-	writeChan chan IPCMsg
-	readChan  chan IPCMsg
-	addr      common.DebugAddr
+	writeChan          chan IPCMsg
+	readChan           chan IPCMsg
+	addr               common.DebugAddr
+	readDeadline       time.Time
+	updateReadDeadline chan time.Time
 }
 
 func (c BroflakeConn) LocalAddr() net.Addr {
 	return c.addr
 }
 
 func (c BroflakeConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
-	msg := <-c.readChan
-	payload := msg.Data.([]byte)
-	copy(p, payload)
-	return len(payload), common.DebugAddr("DEBUG NELSON WUZ HERE"), nil
+	for {
+		var ctx context.Context
+
+		// If the deadline is zero value, never expire; otherwise obey the deadline
+		if c.readDeadline.IsZero() {
+			ctx, _ = context.WithCancel(context.Background())
+		} else {
+			ctx, _ = context.WithDeadline(context.Background(), c.readDeadline)
+		}
+
+		select {
+		case msg := <-c.readChan:
+			// The read completed, let's return some bytes!
+			payload := msg.Data.([]byte)
+			copy(p, payload)
+			return len(payload), common.DebugAddr("DEBUG NELSON WUZ HERE"), nil
+		case <-ctx.Done():
+			// We're past our deadline, so let's return failure!
+			return 0, common.DebugAddr("DEBUG NELSON WUZ HERE"), ctx.Err()
+		case d := <-c.updateReadDeadline:
+			// Someone updated the read deadline, so let's iterate to respect the new deadline
+			c.readDeadline = d
+		}
+	}
 }
 
 func (c BroflakeConn) WriteTo(p []byte, addr net.Addr) (n int, err error) {
@@ -49,6 +72,16 @@ func (c BroflakeConn) WriteTo(p []byte, addr net.Addr) (n int, err error) {
 	return len(b), nil
 }
 
+// XXX: A note about deadlines: as of quic-go 0.34, the QUIC dialer didn't seem to care about read
+// or write deadlines, and it was happy to use a net.PacketConn which didn't properly implement them.
+// But when we bumped to quic-go 0.40, it emerged that the dialer wouldn't work unless we added
+// support for read deadlines. Since there's still no evidence that the dialer cares about write
+// deadlines, we haven't added support for those yet.
+func (c BroflakeConn) SetReadDeadline(t time.Time) error {
+	c.updateReadDeadline <- t
+	return nil
+}
+
 func NewProducerUserStream(wg *sync.WaitGroup) (*BroflakeConn, *WorkerFSM) {
 	worker := NewWorkerFSM(wg, []FSMstate{
 		FSMstate(func(ctx context.Context, com *ipcChan, input []interface{}) (int, []interface{}) {
@@ -61,10 +94,12 @@ func NewProducerUserStream(wg *sync.WaitGroup) (*BroflakeConn, *WorkerFSM) {
 	})
 
 	bfconn := BroflakeConn{
-		PacketConn: &net.UDPConn{},
-		writeChan:  worker.com.tx,
-		readChan:   worker.com.rx,
-		addr:       common.DebugAddr(uuid.NewString()),
+		PacketConn:         &net.UDPConn{},
+		writeChan:          worker.com.tx,
+		readChan:           worker.com.rx,
+		addr:               common.DebugAddr(uuid.NewString()),
+		readDeadline:       time.Time{},
+		updateReadDeadline: make(chan time.Time, 512),
 	}
 
 	return &bfconn, worker

cmd/proxy.go

@@ -52,7 +52,7 @@ func runLocalProxy(port string, bfconn *clientcore.BroflakeConn, ca, sn string)
 		return
 	}
 
-	ql.DialAndMaintainQUICConnection()
+	go ql.DialAndMaintainQUICConnection()
 	proxy.Tr = clientcore.CreateHTTPTransport(ql)
 
 	proxy.OnRequest().DoFunc(

go.mod

@@ -10,12 +10,12 @@ require (
 	github.com/getlantern/telemetry v0.0.0-20230523155019-be7c1d8cd8cb
 	github.com/google/uuid v1.3.0
 	github.com/pion/webrtc/v3 v3.2.6
-	github.com/quic-go/quic-go v0.34.0
+	github.com/quic-go/quic-go v0.40.0
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.42.0
 	go.opentelemetry.io/otel v1.16.0
 	go.opentelemetry.io/otel/metric v1.16.0
 	go.opentelemetry.io/otel/trace v1.16.0
-	golang.org/x/mod v0.8.0
+	golang.org/x/mod v0.11.0
 	nhooyr.io/websocket v1.8.7
 )
 
@@ -25,13 +25,13 @@ require (
 	github.com/felixge/httpsnoop v1.0.3 // indirect
 	github.com/go-logr/logr v1.2.4 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
-	github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0 // indirect
+	github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572 // indirect
 	github.com/golang/mock v1.6.0 // indirect
 	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/google/pprof v0.0.0-20210407192527-94a9f03dee38 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.7.0 // indirect
 	github.com/klauspost/compress v1.10.3 // indirect
-	github.com/onsi/ginkgo/v2 v2.2.0 // indirect
+	github.com/onsi/ginkgo/v2 v2.9.5 // indirect
 	github.com/pion/datachannel v1.5.5 // indirect
 	github.com/pion/dtls/v2 v2.2.7 // indirect
 	github.com/pion/ice/v2 v2.3.5 // indirect
@@ -52,7 +52,7 @@ require (
 	github.com/pkg/errors v0.8.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/quic-go/qtls-go1-19 v0.3.2 // indirect
-	github.com/quic-go/qtls-go1-20 v0.2.2 // indirect
+	github.com/quic-go/qtls-go1-20 v0.4.1 // indirect
 	github.com/stretchr/testify v1.8.3 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.16.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlpmetric v0.39.0 // indirect
@@ -62,12 +62,13 @@ require (
 	go.opentelemetry.io/otel/sdk v1.16.0 // indirect
 	go.opentelemetry.io/otel/sdk/metric v0.39.0 // indirect
 	go.opentelemetry.io/proto/otlp v0.19.0 // indirect
+	go.uber.org/mock v0.3.0 // indirect
 	golang.org/x/crypto v0.9.0 // indirect
 	golang.org/x/exp v0.0.0-20221205204356-47842c84f3db // indirect
 	golang.org/x/net v0.10.0 // indirect
 	golang.org/x/sys v0.8.0 // indirect
 	golang.org/x/text v0.9.0 // indirect
-	golang.org/x/tools v0.6.0 // indirect
+	golang.org/x/tools v0.9.1 // indirect
 	google.golang.org/genproto v0.0.0-20230306155012-7f2fa6fef1f4 // indirect
 	google.golang.org/grpc v1.55.0 // indirect
 	google.golang.org/protobuf v1.30.0 // indirect

go.sum

@@ -93,6 +93,8 @@ github.com/go-playground/validator/v10 v10.2.0 h1:KgJ0snyC2R9VXYN2rneOtQcw5aHQB1
 github.com/go-playground/validator/v10 v10.2.0/go.mod h1:uOYAAleCW8F/7oMFd6aG0GOhaH6EGOAJShg8Id5JGkI=
 github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0 h1:p104kn46Q8WdvHunIJ9dAyjPVtrBPhSr3KT2yUst43I=
 github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0/go.mod h1:fyg7847qk6SyHyPtNmDHnmrv/HOrqktSC+C9fM+CJOE=
+github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572 h1:tfuBGBXKqDEevZMzYi5KSi8KkcZtzBcTgAUUtapy0OI=
+github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572/go.mod h1:9Pwr4B2jHnOSGXyyzV8ROjYa2ojvAY6HCGYYfMoC3Ls=
 github.com/gobwas/httphead v0.0.0-20180130184737-2c6c146eadee h1:s+21KNqlpePfkah2I+gwHF8xmJWRjooY+5248k6m4A0=
 github.com/gobwas/httphead v0.0.0-20180130184737-2c6c146eadee/go.mod h1:L0fX3K22YWvt/FAX9NnzrNzcI4wNYi9Yku4O0LKYflo=
 github.com/gobwas/pool v0.2.0 h1:QEmUOlnSjWtnpRGHF3SauEiOsy82Cup83Vf2LcMlnc8=
@@ -202,10 +204,13 @@ github.com/onsi/ginkgo v1.16.4/go.mod h1:dX+/inL/fNMqNlz0e9LfyB9TswhZpCVdJM/Z6Vv
 github.com/onsi/ginkgo v1.16.5/go.mod h1:+E8gABHa3K6zRBolWtd+ROzc/U5bkGt0FwiG042wbpU=
 github.com/onsi/ginkgo/v2 v2.2.0 h1:3ZNA3L1c5FYDFTTxbFeVGGD8jYvjYauHD30YgLxVsNI=
 github.com/onsi/ginkgo/v2 v2.2.0/go.mod h1:MEH45j8TBi6u9BMogfbp0stKC5cdGjumZj5Y7AG4VIk=
+github.com/onsi/ginkgo/v2 v2.9.5 h1:+6Hr4uxzP4XIUyAkg61dWBw8lb/gc4/X5luuxN/EC+Q=
+github.com/onsi/ginkgo/v2 v2.9.5/go.mod h1:tvAoo1QUJwNEU2ITftXTpR7R1RbCzoZUOs3RonqW57k=
 github.com/onsi/gomega v1.7.1/go.mod h1:XdKZgCCFLUoM/7CFJVPcG8C1xQ1AJ0vpAezJrB7JYyY=
 github.com/onsi/gomega v1.10.1/go.mod h1:iN09h71vgCQne3DLsj+A5owkum+a2tYe+TOCB1ybHNo=
 github.com/onsi/gomega v1.17.0/go.mod h1:HnhC7FXeEQY45zxNK3PPoIUhzk/80Xly9PcubAlGdZY=
 github.com/onsi/gomega v1.20.1 h1:PA/3qinGoukvymdIDV8pii6tiZgC8kbmJO6Z5+b002Q=
+github.com/onsi/gomega v1.27.6 h1:ENqfyGeS5AX/rlXDd/ETokDz93u0YufY1Pgxuy/PvWE=
 github.com/pion/datachannel v1.5.5 h1:10ef4kwdjije+M9d7Xm9im2Y3O6A6ccQb0zcqZcJew8=
 github.com/pion/datachannel v1.5.5/go.mod h1:iMz+lECmfdCMqFRhXhcA/219B0SQlbpoR2V118yimL0=
 github.com/pion/dtls/v2 v2.2.6/go.mod h1:t8fWJCIquY5rlQZwA2yWxUS1+OCrAdXrhVKXB5oD/wY=
@@ -263,8 +268,12 @@ github.com/quic-go/qtls-go1-19 v0.3.2 h1:tFxjCFcTQzK+oMxG6Zcvp4Dq8dx4yD3dDiIiyc8
 github.com/quic-go/qtls-go1-19 v0.3.2/go.mod h1:ySOI96ew8lnoKPtSqx2BlI5wCpUVPT05RMAlajtnyOI=
 github.com/quic-go/qtls-go1-20 v0.2.2 h1:WLOPx6OY/hxtTxKV1Zrq20FtXtDEkeY00CGQm8GEa3E=
 github.com/quic-go/qtls-go1-20 v0.2.2/go.mod h1:JKtK6mjbAVcUTN/9jZpvLbGxvdWIKS8uT7EiStoU1SM=
+github.com/quic-go/qtls-go1-20 v0.4.1 h1:D33340mCNDAIKBqXuAvexTNMUByrYmFYVfKfDN5nfFs=
+github.com/quic-go/qtls-go1-20 v0.4.1/go.mod h1:X9Nh97ZL80Z+bX/gUXMbipO6OxdiDi58b/fMC9mAL+k=
 github.com/quic-go/quic-go v0.34.0 h1:OvOJ9LFjTySgwOTYUZmNoq0FzVicP8YujpV0kB7m2lU=
 github.com/quic-go/quic-go v0.34.0/go.mod h1:+4CVgVppm0FNjpG3UcX8Joi/frKOH7/ciD5yGcwOO1g=
+github.com/quic-go/quic-go v0.40.0 h1:GYd1iznlKm7dpHD7pOVpUvItgMPo/jrMgDWZhMCecqw=
+github.com/quic-go/quic-go v0.40.0/go.mod h1:PeN7kuVJ4xZbxSv/4OX6S1USOX8MJvydwpTx31vx60c=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
 github.com/rogpeppe/go-charset v0.0.0-20180617210344-2471d30d28b4/go.mod h1:qgYeAmZ5ZIpBWTGllZSQnw97Dj+woV0toclVaRGI8pc=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
@@ -276,6 +285,7 @@ github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpE
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
+github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
@@ -323,6 +333,8 @@ go.opentelemetry.io/otel/trace v1.16.0/go.mod h1:Yt9vYq1SdNz3xdjZZK7wcXv1qv2pwLk
 go.opentelemetry.io/proto/otlp v0.7.0/go.mod h1:PqfVotwruBrMGOCsRd/89rSnXhoiJIqeYNgFYFoEGnI=
 go.opentelemetry.io/proto/otlp v0.19.0 h1:IVN6GR+mhC4s5yfcTbmzHYODqvWAp3ZedA2SJPI1Nnw=
 go.opentelemetry.io/proto/otlp v0.19.0/go.mod h1:H7XAot3MsfNsj7EXtrA2q5xSNQ10UqI405h3+duxN4U=
+go.uber.org/mock v0.3.0 h1:3mUxI1No2/60yUYax92Pt8eNOEecx2D3lcXZh2NEZJo=
+go.uber.org/mock v0.3.0/go.mod h1:a6FSlNadKUHUa9IP5Vyt1zh4fC7uAwxMutEAscFbkZc=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20190510104115-cbcb75029529/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20190605123033-f99c8df09eb5/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
@@ -369,6 +381,8 @@ golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
 golang.org/x/mod v0.8.0 h1:LUYupSeNrTNCGzR/hVBk2NHZO4hXcVaW1k4Qx7rjPx8=
 golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/mod v0.11.0 h1:bUO06HqtnRcc/7l71XBe4WcqTZ+3AH1J59zWDDwLKgU=
+golang.org/x/mod v0.11.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -545,6 +559,8 @@ golang.org/x/tools v0.1.1/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
 golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
 golang.org/x/tools v0.6.0 h1:BOw41kyTf3PuCW1pVQf8+Cyg8pMlkYB1oo9iJ6D/lKM=
 golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
+golang.org/x/tools v0.9.1 h1:8WMNJAz3zrtPmnYC7ISf5dEn3MT0gY7jBJfw27yrrLo=
+golang.org/x/tools v0.9.1/go.mod h1:owI94Op576fPu3cIGQeHs3joujW/2Oc6MtlxbF5dfNc=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=