rc: reject out of range integer parameters instead of truncating them

This was spotted by CodeQL after this change was merged:

976d05e1d rc: fix rc API accepting an out of range number and overflowing 64 bits

(cherry picked from commit 7723091be9)

fs/rc/internal.go

@@ -305,15 +305,14 @@ func init() {
 
 // Terminates app
 func rcQuit(ctx context.Context, in Params) (out Params, err error) {
-	code, err := in.GetInt64("exitCode")
+	exitCode, err := in.GetInt("exitCode")
 
 	if IsErrParamInvalid(err) {
 		return nil, err
 	}
 	if IsErrParamNotFound(err) {
-		code = 0
+		exitCode = 0
 	}
-	exitCode := int(code)
 
 	go func(exitCode int) {
 		time.Sleep(time.Millisecond * 1500)
@@ -353,11 +352,11 @@ Results:
 }
 
 func rcSetMutexProfileFraction(ctx context.Context, in Params) (out Params, err error) {
-	rate, err := in.GetInt64("rate")
+	rate, err := in.GetInt("rate")
 	if err != nil {
 		return nil, err
 	}
-	previousRate := runtime.SetMutexProfileFraction(int(rate))
+	previousRate := runtime.SetMutexProfileFraction(rate)
 	out = make(Params)
 	out["previousRate"] = previousRate
 	return out, nil
@@ -388,11 +387,11 @@ Parameters:
 }
 
 func rcSetBlockProfileRate(ctx context.Context, in Params) (out Params, err error) {
-	rate, err := in.GetInt64("rate")
+	rate, err := in.GetInt("rate")
 	if err != nil {
 		return nil, err
 	}
-	runtime.SetBlockProfileRate(int(rate))
+	runtime.SetBlockProfileRate(rate)
 	return nil, nil
 }
 
@@ -471,11 +470,11 @@ Parameters:
 }
 
 func rcSetGCPercent(ctx context.Context, in Params) (out Params, err error) {
-	gcPercent, err := in.GetInt64("gc-percent")
+	gcPercent, err := in.GetInt("gc-percent")
 	if err != nil {
 		return nil, err
 	}
-	oldGCPercent := debug.SetGCPercent(int(gcPercent))
+	oldGCPercent := debug.SetGCPercent(gcPercent)
 	out = Params{
 		"existing-gc-percent": oldGCPercent,
 	}

fs/rc/jobs/job.go

@@ -689,10 +689,10 @@ func rcBatch(ctx context.Context, in rc.Params) (out rc.Params, err error) {
 	}
 
 	// Read concurrency
-	concurrency, err := in.GetInt64("concurrency")
+	concurrency, err := in.GetInt("concurrency")
 	if rc.IsErrParamNotFound(err) {
 		ci := fs.GetConfig(ctx)
-		concurrency = int64(ci.Transfers)
+		concurrency = ci.Transfers
 	} else if err != nil {
 		return nil, err
 	}
@@ -702,7 +702,7 @@ func rcBatch(ctx context.Context, in rc.Params) (out rc.Params, err error) {
 	out["results"] = results
 
 	g, gCtx := errgroup.WithContext(ctx)
-	g.SetLimit(int(concurrency))
+	g.SetLimit(concurrency)
 	for i, inputAny := range inputs {
 		input, ok := inputAny.(map[string]any)
 		if !ok {

fs/rc/params.go

@@ -182,6 +182,22 @@ func (p Params) GetInt64(key string) (int64, error) {
 	return 0, ErrParamInvalid{fmt.Errorf("expecting int64 value for key %q (was %T)", key, value)}
 }
 
+// GetInt gets an int parameter from the input
+//
+// If the parameter isn't found then error will be of type
+// ErrParamNotFound and the returned value will be 0. If the value
+// doesn't fit in an int then the error will be of type ErrParamInvalid.
+func (p Params) GetInt(key string) (int, error) {
+	i, err := p.GetInt64(key)
+	if err != nil {
+		return 0, err
+	}
+	if i > math.MaxInt || i < math.MinInt {
+		return 0, ErrParamInvalid{fmt.Errorf("key %q (%v) overflows int", key, i)}
+	}
+	return int(i), nil
+}
+
 // GetFloat64 gets a float64 parameter from the input
 //
 // If the parameter isn't found then error will be of type

fs/rc/params_test.go

@@ -158,6 +158,41 @@ func TestParamsGetInt64(t *testing.T) {
 	assert.Equal(t, true, IsErrParamInvalid(e3), e3.Error())
 }
 
+func TestParamsGetInt(t *testing.T) {
+	in := Params{
+		"int":      "123",
+		"bad":      "123x",
+		"notInt":   []string{"a", "b"},
+		"maxInt":   int64(math.MaxInt),
+		"minInt":   int64(math.MinInt),
+		"overflow": "9223372036854775808",
+	}
+	v, err := in.GetInt("int")
+	require.NoError(t, err)
+	assert.Equal(t, 123, v)
+	v, err = in.GetInt("maxInt")
+	require.NoError(t, err)
+	assert.Equal(t, math.MaxInt, v)
+	v, err = in.GetInt("minInt")
+	require.NoError(t, err)
+	assert.Equal(t, math.MinInt, v)
+	for _, key := range []string{"bad", "notInt", "overflow"} {
+		v, err = in.GetInt(key)
+		assert.True(t, IsErrParamInvalid(err), key)
+		assert.Equal(t, 0, v)
+	}
+	v, err = in.GetInt("notFound")
+	assert.Equal(t, ErrParamNotFound("notFound"), err)
+	assert.Equal(t, 0, v)
+	if math.MaxInt == math.MaxInt32 {
+		in["big"] = int64(math.MaxInt32) + 1
+		v, err = in.GetInt("big")
+		assert.True(t, IsErrParamInvalid(err))
+		assert.Contains(t, err.Error(), "overflows int")
+		assert.Equal(t, 0, v)
+	}
+}
+
 func TestParamsGetFloat64(t *testing.T) {
 	for _, test := range []struct {
 		value     any