gitlab-org--gitlab-foss/workhorse/internal/staticpages/servefile.go

106 lines
2.7 KiB
Go

package staticpages
import (
"errors"
"fmt"
"net/http"
"os"
"path/filepath"
"strings"
"time"
"gitlab.com/gitlab-org/labkit/mask"
"gitlab.com/gitlab-org/gitlab/workhorse/internal/helper"
"gitlab.com/gitlab-org/gitlab/workhorse/internal/log"
"gitlab.com/gitlab-org/gitlab/workhorse/internal/urlprefix"
)
type CacheMode int
const (
CacheDisabled CacheMode = iota
CacheExpireMax
)
// BUG/QUIRK: If a client requests 'foo%2Fbar' and 'foo/bar' exists,
// handleServeFile will serve foo/bar instead of passing the request
// upstream.
func (s *Static) ServeExisting(prefix urlprefix.Prefix, cache CacheMode, notFoundHandler http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if notFoundHandler == nil {
notFoundHandler = http.HandlerFunc(http.NotFound)
}
// We intentionally use r.URL.Path instead of r.URL.EscaptedPath() below.
// This is to make it possible to serve static files with e.g. a space
// %20 in their name.
relativePath, err := s.validatePath(prefix.Strip(r.URL.Path))
if err != nil {
notFoundHandler.ServeHTTP(w, r)
return
}
file := filepath.Join(s.DocumentRoot, relativePath)
if !strings.HasPrefix(file, s.DocumentRoot) {
log.WithRequest(r).WithError(errPathTraversal).Error()
notFoundHandler.ServeHTTP(w, r)
return
}
var content *os.File
var fi os.FileInfo
// Serve pre-gzipped assets
if acceptEncoding := r.Header.Get("Accept-Encoding"); strings.Contains(acceptEncoding, "gzip") {
content, fi, err = helper.OpenFile(file + ".gz")
if err == nil {
w.Header().Set("Content-Encoding", "gzip")
}
}
// If not found, open the original file
if content == nil || err != nil {
content, fi, err = helper.OpenFile(file)
}
if err != nil {
notFoundHandler.ServeHTTP(w, r)
return
}
w.Header().Set("X-Content-Type-Options", "nosniff")
defer content.Close()
switch cache {
case CacheExpireMax:
// Cache statically served files for 1 year
cacheUntil := time.Now().AddDate(1, 0, 0).Format(http.TimeFormat)
w.Header().Set("Cache-Control", "public")
w.Header().Set("Expires", cacheUntil)
}
log.WithContextFields(r.Context(), log.Fields{
"file": file,
"encoding": w.Header().Get("Content-Encoding"),
"method": r.Method,
"uri": mask.URL(r.RequestURI),
}).Info("Send static file")
http.ServeContent(w, r, filepath.Base(file), fi.ModTime(), content)
})
}
var errPathTraversal = errors.New("path traversal")
func (s *Static) validatePath(filename string) (string, error) {
filename = filepath.Clean(filename)
for _, exc := range s.Exclude {
if strings.HasPrefix(filename, exc) {
return "", fmt.Errorf("file is excluded: %s", exc)
}
}
return filename, nil
}