1 files changed, 88 insertions, 0 deletions
diff --git a/plugins/http/static/static.go b/plugins/http/static/static.go
new file mode 100644
index 00000000..d0278466
--- /dev/null
+++ b/plugins/http/static/static.go
@@ -0,0 +1,88 @@
+package static
+
+import (
+	"io/fs"
+	"net/http"
+	"path/filepath"
+	"strings"
+
+	httpConfig "github.com/spiral/roadrunner/v2/plugins/http/config"
+)
+
+type ExtensionFilter struct {
+	allowed   map[string]struct{}
+	forbidden map[string]struct{}
+}
+
+func NewExtensionFilter(allow, forbid []string) *ExtensionFilter {
+	ef := &ExtensionFilter{
+		allowed:   make(map[string]struct{}, len(allow)),
+		forbidden: make(map[string]struct{}, len(forbid)),
+	}
+
+	for i := 0; i < len(forbid); i++ {
+		// skip empty lines
+		if forbid[i] == "" {
+			continue
+		}
+		ef.forbidden[forbid[i]] = struct{}{}
+	}
+
+	for i := 0; i < len(allow); i++ {
+		// skip empty lines
+		if allow[i] == "" {
+			continue
+		}
+		ef.allowed[allow[i]] = struct{}{}
+	}
+
+	// check if any forbidden items presented in the allowed
+	// if presented, delete such items from allowed
+	for k := range ef.allowed {
+		if _, ok := ef.forbidden[k]; ok {
+			delete(ef.allowed, k)
+		}
+	}
+
+	return ef
+}
+
+type FileSystem struct {
+	ef *ExtensionFilter
+	// embedded
+	http.FileSystem
+}
+
+// Open wrapper around http.FileSystem Open method, name here is the name of the
+func (f FileSystem) Open(name string) (http.File, error) {
+	file, err := f.FileSystem.Open(name)
+	if err != nil {
+		return nil, err
+	}
+
+	fstat, err := file.Stat()
+	if err != nil {
+		return nil, fs.ErrNotExist
+	}
+
+	if fstat.IsDir() {
+		return nil, fs.ErrPermission
+	}
+
+	ext := strings.ToLower(filepath.Ext(fstat.Name()))
+	if _, ok := f.ef.forbidden[ext]; ok {
+		return nil, fs.ErrPermission
+	}
+
+	// if file extension is allowed, append it to the FileInfo slice
+	if _, ok := f.ef.allowed[ext]; ok {
+		return file, nil
+	}
+
+	return nil, fs.ErrNotExist
+}
+
+// FS is a constructor for the http.FileSystem
+func FS(config *httpConfig.Static) http.FileSystem {
+	return FileSystem{NewExtensionFilter(config.Allow, config.Forbid), http.Dir(config.Dir)}
+}