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// Copyright 2015 Matthew Holt and The Caddy Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package fileserver
import (
"bytes"
"encoding/json"
"fmt"
"net/http"
"os"
"path"
"strings"
"text/template"
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/modules/caddyhttp"
"github.com/caddyserver/caddy/v2/modules/caddyhttp/templates"
"go.uber.org/zap"
)
// Browse configures directory browsing.
type Browse struct {
// Use this template file instead of the default browse template.
TemplateFile string `json:"template_file,omitempty"`
template *template.Template
}
func (fsrv *FileServer) serveBrowse(root, dirPath string, w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error {
fsrv.logger.Debug("browse enabled; listing directory contents",
zap.String("path", dirPath),
zap.String("root", root))
// navigation on the client-side gets messed up if the
// URL doesn't end in a trailing slash because hrefs like
// "/b/c" on a path like "/a" end up going to "/b/c" instead
// of "/a/b/c" - so we have to redirect in this case
if !strings.HasSuffix(r.URL.Path, "/") {
fsrv.logger.Debug("redirecting to trailing slash to preserve hrefs", zap.String("request_path", r.URL.Path))
r.URL.Path += "/"
http.Redirect(w, r, r.URL.String(), http.StatusMovedPermanently)
return nil
}
dir, err := fsrv.openFile(dirPath, w)
if err != nil {
return err
}
defer dir.Close()
repl := r.Context().Value(caddy.ReplacerCtxKey).(*caddy.Replacer)
// calling path.Clean here prevents weird breadcrumbs when URL paths are sketchy like /%2e%2e%2f
listing, err := fsrv.loadDirectoryContents(dir, root, path.Clean(r.URL.Path), repl)
switch {
case os.IsPermission(err):
return caddyhttp.Error(http.StatusForbidden, err)
case os.IsNotExist(err):
return fsrv.notFound(w, r, next)
case err != nil:
return caddyhttp.Error(http.StatusInternalServerError, err)
}
fsrv.browseApplyQueryParams(w, r, &listing)
// write response as either JSON or HTML
var buf *bytes.Buffer
acceptHeader := strings.ToLower(strings.Join(r.Header["Accept"], ","))
if strings.Contains(acceptHeader, "application/json") {
if buf, err = fsrv.browseWriteJSON(listing); err != nil {
return caddyhttp.Error(http.StatusInternalServerError, err)
}
w.Header().Set("Content-Type", "application/json; charset=utf-8")
} else {
var fs http.FileSystem
if fsrv.Root != "" {
fs = http.Dir(repl.ReplaceAll(fsrv.Root, "."))
}
var tplCtx = &templateContext{
TemplateContext: templates.TemplateContext{
Root: fs,
Req: r,
RespHeader: templates.WrappedHeader{Header: w.Header()},
},
browseTemplateContext: listing,
}
err = fsrv.makeBrowseTemplate(tplCtx)
if err != nil {
return fmt.Errorf("parsing browse template: %v", err)
}
if buf, err = fsrv.browseWriteHTML(tplCtx); err != nil {
return caddyhttp.Error(http.StatusInternalServerError, err)
}
w.Header().Set("Content-Type", "text/html; charset=utf-8")
}
_, _ = buf.WriteTo(w)
return nil
}
func (fsrv *FileServer) loadDirectoryContents(dir *os.File, root, urlPath string, repl *caddy.Replacer) (browseTemplateContext, error) {
files, err := dir.Readdir(-1)
if err != nil {
return browseTemplateContext{}, err
}
// user can presumably browse "up" to parent folder if path is longer than "/"
canGoUp := len(urlPath) > 1
return fsrv.directoryListing(files, canGoUp, root, urlPath, repl), nil
}
// browseApplyQueryParams applies query parameters to the listing.
// It mutates the listing and may set cookies.
func (fsrv *FileServer) browseApplyQueryParams(w http.ResponseWriter, r *http.Request, listing *browseTemplateContext) {
sortParam := r.URL.Query().Get("sort")
orderParam := r.URL.Query().Get("order")
limitParam := r.URL.Query().Get("limit")
offsetParam := r.URL.Query().Get("offset")
// first figure out what to sort by
switch sortParam {
case "":
sortParam = sortByNameDirFirst
if sortCookie, sortErr := r.Cookie("sort"); sortErr == nil {
sortParam = sortCookie.Value
}
case sortByName, sortByNameDirFirst, sortBySize, sortByTime:
http.SetCookie(w, &http.Cookie{Name: "sort", Value: sortParam, Secure: r.TLS != nil})
}
// then figure out the order
switch orderParam {
case "":
orderParam = "asc"
if orderCookie, orderErr := r.Cookie("order"); orderErr == nil {
orderParam = orderCookie.Value
}
case "asc", "desc":
http.SetCookie(w, &http.Cookie{Name: "order", Value: orderParam, Secure: r.TLS != nil})
}
// finally, apply the sorting and limiting
listing.applySortAndLimit(sortParam, orderParam, limitParam, offsetParam)
}
// makeBrowseTemplate creates the template to be used for directory listings.
func (fsrv *FileServer) makeBrowseTemplate(tplCtx *templateContext) error {
var tpl *template.Template
var err error
if fsrv.Browse.TemplateFile != "" {
tpl = tplCtx.NewTemplate(path.Base(fsrv.Browse.TemplateFile))
tpl, err = tpl.ParseFiles(fsrv.Browse.TemplateFile)
if err != nil {
return fmt.Errorf("parsing browse template file: %v", err)
}
} else {
tpl = tplCtx.NewTemplate("default_listing")
tpl, err = tpl.Parse(defaultBrowseTemplate)
if err != nil {
return fmt.Errorf("parsing default browse template: %v", err)
}
}
fsrv.Browse.template = tpl
return nil
}
func (fsrv *FileServer) browseWriteJSON(listing browseTemplateContext) (*bytes.Buffer, error) {
buf := bufPool.Get().(*bytes.Buffer)
defer bufPool.Put(buf)
err := json.NewEncoder(buf).Encode(listing.Items)
return buf, err
}
func (fsrv *FileServer) browseWriteHTML(tplCtx *templateContext) (*bytes.Buffer, error) {
buf := bufPool.Get().(*bytes.Buffer)
defer bufPool.Put(buf)
err := fsrv.Browse.template.Execute(buf, tplCtx)
return buf, err
}
// isSymlink return true if f is a symbolic link
func isSymlink(f os.FileInfo) bool {
return f.Mode()&os.ModeSymlink != 0
}
// isSymlinkTargetDir returns true if f's symbolic link target
// is a directory.
func isSymlinkTargetDir(f os.FileInfo, root, urlPath string) bool {
if !isSymlink(f) {
return false
}
target := sanitizedPathJoin(root, path.Join(urlPath, f.Name()))
targetInfo, err := os.Stat(target)
if err != nil {
return false
}
return targetInfo.IsDir()
}
// templateContext powers the context used when evaluating the browse template.
// It combines browse-specific features with the standard templates handler
// features.
type templateContext struct {
templates.TemplateContext
browseTemplateContext
}
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