feat(serverHandler): prevent mutate items under directory if aliased

Author: marjune163

README.md

@@ -120,12 +120,12 @@ server [options]
     Specify default index file for directory.
 
 -a|--alias <separator><url-path><separator><fs-path> ...
-    Set path alias. e.g. ":/doc:/usr/share/doc"
+    Set path alias.
+    Mount a file system path to URL path.
+    e.g. ":/doc:/usr/share/doc"
 
 -U|--global-upload
     Allow upload files for all url paths.
-    If filename exists, will try to remove it first if deleting is enabled(e.g. by --delete),
-    otherwise will try to add or increase numeric suffix.
     Use it with care.
 -u|--upload <url-path> ...
     Set url paths(and sub paths) that allows to upload files.
@@ -134,20 +134,33 @@ server [options]
     Similar to --upload, but use file system path instead of url path.
     Use it with care.
 
+    Notes for upload options:
+        If filename exists and is a regular file,
+        will try to remove it first if deleting is enabled(e.g. by --delete),
+        otherwise will try to add or increase numeric suffix.
+
 --global-mkdir
     Allow create sub directory under all url paths.
 --mkdir <url-path> ...
     Allow create sub directory under specific url paths(and sub paths).
 --mkdir-dir <fs-path> ...
     Similar to --mkdir, but use file system path instead of url path.
 
+    Notes for mkdir options:
+        To avoid ambiguity, names shadowed by aliased items cannot be created.
+
 --global-delete
     Allow delete items under all url paths.
 --delete <url-path> ...
     Allow delete items under specific url paths(and sub paths).
 --delete-dir <fs-path> ...
     Similar to --delete, but use file system path instead of url path.
 
+    Notes for delete options:
+        To avoid ambiguity, aliased items under a path cannot be deleted.
+        Non-aliased files/directories inside aliased items still can be deleted.
+        To avoid ambiguity, files/directories shadowed by aliased items cannot be deleted.
+
 -A|--global-archive
     Allow user to download the whole contents of current directory for all url paths.
     A download link will appear on top part of the page.

README.zh-CN.md

@@ -118,33 +118,46 @@ server [选项]
     指定目录默认页面文件。
 
 -a|--alias <分隔符><URL路径><分隔符><文件系统路径> ...
-    设置路径别名。例如：“:/doc:/usr/share/doc”。
+    设置路径别名。
+    将某个文件系统路径挂载到URL路径下。
+    例如：“:/doc:/usr/share/doc”。
 
 -U|--global-upload
     对所有URL路径开启上传权限。
-    如果文件已存在，若已启用删除（例如--delete选项），则尝试先删除文件，
-    否则尝试添加或递增数字后缀。
     请谨慎使用。
 -u|--upload <URL路径> ...
     设置允许上传的URL路径（及子路径）。
     请谨慎使用。
 --upload-dir <文件系统路径> ...
     与--upload类似，但指定的是文件系统路径，而不是URL路径。
 
+    上传选项注意事项：
+        如果名称已存在且是常规文件，
+        若已启用删除（例如--delete选项），则尝试先删除文件，
+        否则尝试添加或递增数字后缀。
+
 --global-mkdir
     对所有URL路径开启创建子目录权限。
 --mkdir <url-path> ...
     设置允许创建子目录的URL路径（及子路径）。
 --mkdir-dir <fs-path> ...
     与--mkdir类似，但指定的是文件系统路径，而不是URL路径。
 
+    创建子目录选项注意事项：
+        为避免歧义，被别名遮蔽的目录名不能被创建。
+
 --global-delete
     对所有URL路径开启删除子项权限。
 --delete <url-path> ...
     设置允许删除子项的URL路径（及子路径）。
 --delete-dir <fs-path> ...
     与--delete类似，但指定的是文件系统路径，而不是URL路径。
 
+    删除选项注意事项：
+        为避免歧义，URL路径下挂载的别名不能被删除。
+        别名下的非别名文件/目录仍然可以被删除。
+        为避免歧义，被别名遮蔽的正常文件/目录不能被删除。
+
 -A|--global-archive
     对所有URL路径开启打包下载当前目录内容的功能。
     页面顶部会出现下载链接。

src/serverHandler/delete.go

@@ -4,10 +4,13 @@ import (
 	"os"
 )
 
-func (h *handler) deleteItems(fsPrefix string, files []string) {
+func (h *handler) deleteItems(fsPrefix string, files []string, aliasSubItems []os.FileInfo) {
 	errs := []error{}
 
 	for _, filename := range files {
+		if containsItem(aliasSubItems, filename) {
+			continue
+		}
 		err := os.RemoveAll(fsPrefix + "/" + filename)
 		if err != nil {
 			errs = append(errs, err)

src/serverHandler/main.go

@@ -90,18 +90,24 @@ func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	}
 
 	switch {
-	case data.CanUpload && r.URL.RawQuery == "upload" && r.Method == http.MethodPost:
-		h.saveUploadFiles(h.root+data.handlerReqPath, data.CanDelete, r)
+	case r.URL.RawQuery == "upload":
+		if data.CanUpload && r.Method == http.MethodPost {
+			h.saveUploadFiles(h.root+data.handlerReqPath, data.CanDelete, data.AliasSubItems, r)
+		}
 		http.Redirect(w, r, r.URL.Path, http.StatusFound)
 		return
-	case data.CanMkdir && strings.HasPrefix(r.URL.RawQuery, "mkdir"):
-		h.errHandler.LogError(r.ParseForm())
-		h.mkdirs(h.root+data.handlerReqPath, r.Form["name"])
+	case strings.HasPrefix(r.URL.RawQuery, "mkdir"):
+		if data.CanMkdir {
+			h.errHandler.LogError(r.ParseForm())
+			h.mkdirs(h.root+data.handlerReqPath, r.Form["name"], data.AliasSubItems)
+		}
 		http.Redirect(w, r, r.URL.Path, http.StatusFound)
 		return
-	case data.CanDelete && strings.HasPrefix(r.URL.RawQuery, "delete"):
-		h.errHandler.LogError(r.ParseForm())
-		h.deleteItems(h.root+data.handlerReqPath, r.Form["name"])
+	case strings.HasPrefix(r.URL.RawQuery, "delete"):
+		if data.CanDelete {
+			h.errHandler.LogError(r.ParseForm())
+			h.deleteItems(h.root+data.handlerReqPath, r.Form["name"], data.AliasSubItems)
+		}
 		http.Redirect(w, r, r.URL.Path, http.StatusFound)
 		return
 	}

src/serverHandler/mkdir.go

@@ -4,10 +4,13 @@ import (
 	"os"
 )
 
-func (h *handler) mkdirs(fsPrefix string, files []string) {
+func (h *handler) mkdirs(fsPrefix string, files []string, aliasSubItems []os.FileInfo) {
 	errs := []error{}
 
 	for _, filename := range files {
+		if containsItem(aliasSubItems, filename) {
+			continue
+		}
 		err := os.Mkdir(fsPrefix+"/"+filename, 0755)
 		if err != nil {
 			errs = append(errs, err)

src/serverHandler/responseData.go

@@ -39,6 +39,7 @@ type responseData struct {
 	Item          os.FileInfo
 	ItemName      string
 	SubItems      []os.FileInfo
+	AliasSubItems []os.FileInfo
 	SubItemsHtml  []*itemHtml
 	SubItemPrefix string
 
@@ -112,11 +113,15 @@ func readdir(file *os.File, item os.FileInfo, visitFs bool) (subItems []os.FileI
 	return file.Readdir(0)
 }
 
-func (h *handler) mergeAlias(rawRequestPath string, item os.FileInfo, subItems []os.FileInfo) ([]os.FileInfo, []error) {
-	errs := []error{}
+func (h *handler) mergeAlias(
+	rawRequestPath string,
+	item os.FileInfo,
+	subItems []os.FileInfo,
+) (mergedSubItems, aliasSubItems []os.FileInfo, errs []error) {
+	errs = []error{}
 
 	if (item != nil && !item.IsDir()) || len(h.aliases) == 0 {
-		return subItems, errs
+		return subItems, nil, errs
 	}
 
 	for _, alias := range h.aliases {
@@ -167,6 +172,7 @@ func (h *handler) mergeAlias(rawRequestPath string, item os.FileInfo, subItems [
 		} else {
 			aliasSubItem = newFakeFileInfo(nextName, true)
 		}
+		aliasSubItems = append(aliasSubItems, aliasSubItem)
 
 		replaced := false
 		for i, subItem := range subItems {
@@ -182,7 +188,7 @@ func (h *handler) mergeAlias(rawRequestPath string, item os.FileInfo, subItems [
 		}
 	}
 
-	return subItems, errs
+	return subItems, aliasSubItems, errs
 }
 
 func getSubItemPrefix(rawRequestPath string, tailSlash bool) string {
@@ -308,7 +314,7 @@ func (h *handler) getResponseData(r *http.Request) (data *responseData) {
 		status = http.StatusInternalServerError
 	}
 
-	subItems, _mergeErrs := h.mergeAlias(rawReqPath, item, subItems)
+	subItems, aliasSubItems, _mergeErrs := h.mergeAlias(rawReqPath, item, subItems)
 	if len(_mergeErrs) > 0 {
 		errs = append(errs, _mergeErrs...)
 		status = http.StatusInternalServerError
@@ -345,6 +351,7 @@ func (h *handler) getResponseData(r *http.Request) (data *responseData) {
 		Item:          item,
 		ItemName:      itemName,
 		SubItems:      subItems,
+		AliasSubItems: aliasSubItems,
 		SubItemsHtml:  nil,
 		SubItemPrefix: subItemPrefix,
 

src/serverHandler/upload.go

@@ -10,15 +10,17 @@ import (
 	"strconv"
 )
 
-func getAvailableFilename(fsPrefix, filename string) string {
+func getAvailableFilename(fsPrefix, filename string, mustAppendSuffix bool) string {
 	if len(fsPrefix) == 0 {
 		fsPrefix = "/"
 	} else if fsPrefix[len(fsPrefix)-1] != '/' {
 		fsPrefix = fsPrefix + "/"
 	}
 
-	if _, err := os.Lstat(fsPrefix + filename); os.IsNotExist(err) {
-		return filename
+	if !mustAppendSuffix {
+		if _, err := os.Lstat(fsPrefix + filename); os.IsNotExist(err) {
+			return filename
+		}
 	}
 
 	filenamePrefix, filenameSuffix := util.SplitFilename(filename)
@@ -33,7 +35,7 @@ func getAvailableFilename(fsPrefix, filename string) string {
 	return ""
 }
 
-func (h *handler) saveUploadFiles(fsPrefix string, overwriteExists bool, r *http.Request) {
+func (h *handler) saveUploadFiles(fsPrefix string, overwriteExists bool, aliasSubItems []os.FileInfo, r *http.Request) {
 	errs := []error{}
 
 	reader, err := r.MultipartReader()
@@ -55,22 +57,29 @@ func (h *handler) saveUploadFiles(fsPrefix string, overwriteExists bool, r *http
 		if len(filename) == 0 {
 			continue
 		}
+
+		isFilenameAliased := containsItem(aliasSubItems, filename)
 		var fsFilename string
-		if overwriteExists {
-			err := os.Remove(fsPrefix + "/" + filename)
-			if err != nil && !os.IsNotExist(err) {
-				errs = append(errs, err)
-				// continue
+		if overwriteExists && !isFilenameAliased {
+			tryPath := fsPrefix + "/" + filename
+			var info os.FileInfo
+			info, err = os.Lstat(tryPath)
+			if info != nil && !info.IsDir() {
+				err = os.Remove(tryPath)
+				if err != nil && !os.IsNotExist(err) {
+					errs = append(errs, err)
+				}
 				// even remove failed, still try to write content to file by TRUNCATE mode
+				fsFilename = filename
 			}
-			fsFilename = filename
-		} else {
-			fsFilename = getAvailableFilename(fsPrefix, filename)
-			if len(fsFilename) == 0 {
-				err := errors.New("no available filename for " + filename)
-				errs = append(errs, err)
-				continue
-			}
+		}
+		if len(fsFilename) == 0 {
+			fsFilename = getAvailableFilename(fsPrefix, filename, isFilenameAliased)
+		}
+		if len(fsFilename) == 0 {
+			err := errors.New("no available filename for " + filename)
+			errs = append(errs, err)
+			continue
 		}
 
 		fsPath := path.Clean(fsPrefix + "/" + fsFilename)

src/serverHandler/util.go

@@ -1,10 +1,22 @@
 package serverHandler
 
-import "net/http"
+import (
+	"net/http"
+	"os"
+)
 
 func needResponseBody(method string) bool {
 	return method != http.MethodHead &&
 		method != http.MethodOptions &&
 		method != http.MethodConnect &&
 		method != http.MethodTrace
 }
+
+func containsItem(infos []os.FileInfo, name string) bool {
+	for i := range infos {
+		if infos[i].Name() == name {
+			return true
+		}
+	}
+	return false
+}