api: fix crash when itemsPerPage is zero and there are items (#3425)

internal/api/api.go

@@ -10,7 +10,6 @@ import (
 	"os"
 	"reflect"
 	"sort"
-	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -36,58 +35,6 @@ func interfaceIsEmpty(i interface{}) bool {
 	return reflect.ValueOf(i).Kind() != reflect.Ptr || reflect.ValueOf(i).IsNil()
 }
 
-func paginate2(itemsPtr interface{}, itemsPerPage int, page int) int {
-	ritems := reflect.ValueOf(itemsPtr).Elem()
-
-	itemsLen := ritems.Len()
-	if itemsLen == 0 {
-		return 0
-	}
-
-	pageCount := (itemsLen / itemsPerPage)
-	if (itemsLen % itemsPerPage) != 0 {
-		pageCount++
-	}
-
-	min := page * itemsPerPage
-	if min > itemsLen {
-		min = itemsLen
-	}
-
-	max := (page + 1) * itemsPerPage
-	if max > itemsLen {
-		max = itemsLen
-	}
-
-	ritems.Set(ritems.Slice(min, max))
-
-	return pageCount
-}
-
-func paginate(itemsPtr interface{}, itemsPerPageStr string, pageStr string) (int, error) {
-	itemsPerPage := 100
-
-	if itemsPerPageStr != "" {
-		tmp, err := strconv.ParseUint(itemsPerPageStr, 10, 31)
-		if err != nil {
-			return 0, err
-		}
-		itemsPerPage = int(tmp)
-	}
-
-	page := 0
-
-	if pageStr != "" {
-		tmp, err := strconv.ParseUint(pageStr, 10, 31)
-		if err != nil {
-			return 0, err
-		}
-		page = int(tmp)
-	}
-
-	return paginate2(itemsPtr, itemsPerPage, page), nil
-}
-
 func sortedKeys(paths map[string]*conf.Path) []string {
 	ret := make([]string, len(paths))
 	i := 0

internal/api/api_test.go

@@ -74,38 +74,6 @@ func checkError(t *testing.T, msg string, body io.Reader) {
 	require.Equal(t, map[string]interface{}{"error": msg}, resErr)
 }
 
-func TestPaginate(t *testing.T) {
-	items := make([]int, 5)
-	for i := 0; i < 5; i++ {
-		items[i] = i
-	}
-
-	pageCount, err := paginate(&items, "1", "1")
-	require.NoError(t, err)
-	require.Equal(t, 5, pageCount)
-	require.Equal(t, []int{1}, items)
-
-	items = make([]int, 5)
-	for i := 0; i < 5; i++ {
-		items[i] = i
-	}
-
-	pageCount, err = paginate(&items, "3", "2")
-	require.NoError(t, err)
-	require.Equal(t, 2, pageCount)
-	require.Equal(t, []int{}, items)
-
-	items = make([]int, 6)
-	for i := 0; i < 6; i++ {
-		items[i] = i
-	}
-
-	pageCount, err = paginate(&items, "4", "1")
-	require.NoError(t, err)
-	require.Equal(t, 2, pageCount)
-	require.Equal(t, []int{4, 5}, items)
-}
-
 func TestConfigAuth(t *testing.T) {
 	cnf := tempConf(t, "api: yes\n")
 

internal/api/paginate.go

@@ -0,0 +1,63 @@
+package api
+
+import (
+	"fmt"
+	"reflect"
+	"strconv"
+)
+
+func paginate2(itemsPtr interface{}, itemsPerPage int, page int) int {
+	ritems := reflect.ValueOf(itemsPtr).Elem()
+
+	itemsLen := ritems.Len()
+	if itemsLen == 0 {
+		return 0
+	}
+
+	pageCount := (itemsLen / itemsPerPage)
+	if (itemsLen % itemsPerPage) != 0 {
+		pageCount++
+	}
+
+	min := page * itemsPerPage
+	if min > itemsLen {
+		min = itemsLen
+	}
+
+	max := (page + 1) * itemsPerPage
+	if max > itemsLen {
+		max = itemsLen
+	}
+
+	ritems.Set(ritems.Slice(min, max))
+
+	return pageCount
+}
+
+func paginate(itemsPtr interface{}, itemsPerPageStr string, pageStr string) (int, error) {
+	itemsPerPage := 100
+
+	if itemsPerPageStr != "" {
+		tmp, err := strconv.ParseUint(itemsPerPageStr, 10, 31)
+		if err != nil {
+			return 0, err
+		}
+		itemsPerPage = int(tmp)
+
+		if itemsPerPage == 0 {
+			return 0, fmt.Errorf("invalid items per page")
+		}
+	}
+
+	page := 0
+
+	if pageStr != "" {
+		tmp, err := strconv.ParseUint(pageStr, 10, 31)
+		if err != nil {
+			return 0, err
+		}
+		page = int(tmp)
+	}
+
+	return paginate2(itemsPtr, itemsPerPage, page), nil
+}

internal/api/paginate_test.go

@@ -0,0 +1,65 @@
+package api
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPaginate(t *testing.T) {
+	func() {
+		items := make([]int, 5)
+		for i := 0; i < 5; i++ {
+			items[i] = i
+		}
+
+		pageCount, err := paginate(&items, "1", "1")
+		require.NoError(t, err)
+		require.Equal(t, 5, pageCount)
+		require.Equal(t, []int{1}, items)
+	}()
+
+	func() {
+		items := make([]int, 5)
+		for i := 0; i < 5; i++ {
+			items[i] = i
+		}
+
+		pageCount, err := paginate(&items, "3", "2")
+		require.NoError(t, err)
+		require.Equal(t, 2, pageCount)
+		require.Equal(t, []int{}, items)
+	}()
+
+	func() {
+		items := make([]int, 6)
+		for i := 0; i < 6; i++ {
+			items[i] = i
+		}
+
+		pageCount, err := paginate(&items, "4", "1")
+		require.NoError(t, err)
+		require.Equal(t, 2, pageCount)
+		require.Equal(t, []int{4, 5}, items)
+	}()
+
+	func() {
+		items := make([]int, 0)
+
+		pageCount, err := paginate(&items, "1", "0")
+		require.NoError(t, err)
+		require.Equal(t, 0, pageCount)
+		require.Equal(t, []int{}, items)
+	}()
+}
+
+func FuzzPaginate(f *testing.F) {
+	f.Fuzz(func(_ *testing.T, str1 string, str2 string) {
+		items := make([]int, 6)
+		for i := 0; i < 6; i++ {
+			items[i] = i
+		}
+
+		paginate(&items, str1, str2) //nolint:errcheck
+	})
+}

internal/api/testdata/fuzz/FuzzPaginate/23731da0f18d31d0

@@ -0,0 +1,3 @@
+go test fuzz v1
+string("A")
+string("0")

internal/api/testdata/fuzz/FuzzPaginate/34523a772174e26e

@@ -0,0 +1,3 @@
+go test fuzz v1
+string("1")
+string("A")

internal/api/testdata/fuzz/FuzzPaginate/85649d45641911d0

@@ -0,0 +1,3 @@
+go test fuzz v1
+string("0")
+string("")