Remove lostcancel warnings.

Updates #2243

5 files changed, 22 insertions, 19 deletions

diff --git a/pkg/tcpip/network/arp/arp_test.go b/pkg/tcpip/network/arp/arp_test.go
index b3e239ac7..1646d9cde 100644
--- a/pkg/tcpip/network/arp/arp_test.go
+++ b/pkg/tcpip/network/arp/arp_test.go
@@ -138,7 +138,8 @@ func TestDirectRequest(t *testing.T) {
 	// Sleep tests are gross, but this will only potentially flake
 	// if there's a bug. If there is no bug this will reliably
 	// succeed.
-	ctx, _ := context.WithTimeout(context.Background(), 100*time.Millisecond)
+	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
+	defer cancel()
 	if pkt, ok := c.linkEP.ReadContext(ctx); ok {
 		t.Errorf("stackAddrBad: unexpected packet sent, Proto=%v", pkt.Proto)
 	}
diff --git a/pkg/tcpip/stack/ndp_test.go b/pkg/tcpip/stack/ndp_test.go
index bc822e3b1..acb2d4731 100644
--- a/pkg/tcpip/stack/ndp_test.go
+++ b/pkg/tcpip/stack/ndp_test.go
@@ -3483,7 +3483,8 @@ func TestRouterSolicitation(t *testing.T) {
 				e.Endpoint.LinkEPCapabilities |= stack.CapabilityResolutionRequired
 				waitForPkt := func(timeout time.Duration) {
 					t.Helper()
-					ctx, _ := context.WithTimeout(context.Background(), timeout)
+					ctx, cancel := context.WithTimeout(context.Background(), timeout)
+					defer cancel()
 					p, ok := e.ReadContext(ctx)
 					if !ok {
 						t.Fatal("timed out waiting for packet")
@@ -3513,7 +3514,8 @@ func TestRouterSolicitation(t *testing.T) {
 				}
 				waitForNothing := func(timeout time.Duration) {
 					t.Helper()
-					ctx, _ := context.WithTimeout(context.Background(), timeout)
+					ctx, cancel := context.WithTimeout(context.Background(), timeout)
+					defer cancel()
 					if _, ok := e.ReadContext(ctx); ok {
 						t.Fatal("unexpectedly got a packet")
 					}
diff --git a/pkg/tcpip/transport/tcp/testing/context/context.go b/pkg/tcpip/transport/tcp/testing/context/context.go
index d4f6bc635..431ab4e6b 100644
--- a/pkg/tcpip/transport/tcp/testing/context/context.go
+++ b/pkg/tcpip/transport/tcp/testing/context/context.go
@@ -217,7 +217,8 @@ func (c *Context) Stack() *stack.Stack {
 func (c *Context) CheckNoPacketTimeout(errMsg string, wait time.Duration) {
 	c.t.Helper()
 
-	ctx, _ := context.WithTimeout(context.Background(), wait)
+	ctx, cancel := context.WithTimeout(context.Background(), wait)
+	defer cancel()
 	if _, ok := c.linkEP.ReadContext(ctx); ok {
 		c.t.Fatal(errMsg)
 	}
@@ -235,7 +236,8 @@ func (c *Context) CheckNoPacket(errMsg string) {
 func (c *Context) GetPacket() []byte {
 	c.t.Helper()
 
-	ctx, _ := context.WithTimeout(context.Background(), 2*time.Second)
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
 	p, ok := c.linkEP.ReadContext(ctx)
 	if !ok {
 		c.t.Fatalf("Packet wasn't written out")
@@ -486,7 +488,8 @@ func (c *Context) CreateV6Endpoint(v6only bool) {
 func (c *Context) GetV6Packet() []byte {
 	c.t.Helper()
 
-	ctx, _ := context.WithTimeout(context.Background(), 2*time.Second)
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
 	p, ok := c.linkEP.ReadContext(ctx)
 	if !ok {
 		c.t.Fatalf("Packet wasn't written out")
diff --git a/pkg/tcpip/transport/udp/udp_test.go b/pkg/tcpip/transport/udp/udp_test.go
index b3fe557ca..fd818243f 100644
--- a/pkg/tcpip/transport/udp/udp_test.go
+++ b/pkg/tcpip/transport/udp/udp_test.go
@@ -358,7 +358,8 @@ func (c *testContext) createEndpointForFlow(flow testFlow) {
 func (c *testContext) getPacketAndVerify(flow testFlow, checkers ...checker.NetworkChecker) []byte {
 	c.t.Helper()
 
-	ctx, _ := context.WithTimeout(context.Background(), 2*time.Second)
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
 	p, ok := c.linkEP.ReadContext(ctx)
 	if !ok {
 		c.t.Fatalf("Packet wasn't written out")
@@ -1563,7 +1564,8 @@ func TestV4UnknownDestination(t *testing.T) {
 			}
 			c.injectPacket(tc.flow, payload)
 			if !tc.icmpRequired {
-				ctx, _ := context.WithTimeout(context.Background(), time.Second)
+				ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+				defer cancel()
 				if p, ok := c.linkEP.ReadContext(ctx); ok {
 					t.Fatalf("unexpected packet received: %+v", p)
 				}
@@ -1571,7 +1573,8 @@ func TestV4UnknownDestination(t *testing.T) {
 			}
 
 			// ICMP required.
-			ctx, _ := context.WithTimeout(context.Background(), time.Second)
+			ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+			defer cancel()
 			p, ok := c.linkEP.ReadContext(ctx)
 			if !ok {
 				t.Fatalf("packet wasn't written out")
@@ -1639,7 +1642,8 @@ func TestV6UnknownDestination(t *testing.T) {
 			}
 			c.injectPacket(tc.flow, payload)
 			if !tc.icmpRequired {
-				ctx, _ := context.WithTimeout(context.Background(), time.Second)
+				ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+				defer cancel()
 				if p, ok := c.linkEP.ReadContext(ctx); ok {
 					t.Fatalf("unexpected packet received: %+v", p)
 				}
@@ -1647,7 +1651,8 @@ func TestV6UnknownDestination(t *testing.T) {
 			}
 
 			// ICMP required.
-			ctx, _ := context.WithTimeout(context.Background(), time.Second)
+			ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+			defer cancel()
 			p, ok := c.linkEP.ReadContext(ctx)
 			if !ok {
 				t.Fatalf("packet wasn't written out")
diff --git a/tools/nogo.json b/tools/nogo.json
index 09bda9212..85fac8604 100644
--- a/tools/nogo.json
+++ b/tools/nogo.json
@@ -9,14 +9,6 @@
       "/external/": "allowed: not subject to unsafe naming rules"
     }
   },
-  "lostcancel": {
-    "exclude_files": {
-      "/pkg/tcpip/network/arp/arp_test.go": "fix: the cancel function returned by context.WithTimeout should be called, not discarded, to avoid a context leak",
-      "/pkg/tcpip/stack/ndp_test.go": "fix: the cancel function returned by context.WithTimeout should be called, not discarded, to avoid a context leak",
-      "/pkg/tcpip/transport/udp/udp_test.go": "fix: the cancel function returned by context.WithTimeout should be called, not discarded, to avoid a context leak",
-      "/pkg/tcpip/transport/tcp/testing/context/context.go": "fix: the cancel function returned by context.WithTimeout should be called, not discarded, to avoid a context leak"
-    }
-  },
   "nilness": {
     "exclude_files": {
       "/com_github_vishvananda_netlink/route_linux.go": "allowed: false positive",