hugo/hugolib/alias.go
2023-06-18 13:03:04 +02:00

173 lines
4.9 KiB
Go

// Copyright 2019 The Hugo Authors. All rights reserved.
//
// 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 hugolib
import (
"bytes"
"context"
"errors"
"fmt"
"io"
"path"
"path/filepath"
"runtime"
"strings"
"github.com/gohugoio/hugo/common/loggers"
"github.com/gohugoio/hugo/output"
"github.com/gohugoio/hugo/publisher"
"github.com/gohugoio/hugo/resources/page"
"github.com/gohugoio/hugo/tpl"
)
type aliasHandler struct {
t tpl.TemplateHandler
log loggers.Logger
allowRoot bool
}
func newAliasHandler(t tpl.TemplateHandler, l loggers.Logger, allowRoot bool) aliasHandler {
return aliasHandler{t, l, allowRoot}
}
type aliasPage struct {
Permalink string
page.Page
}
func (a aliasHandler) renderAlias(permalink string, p page.Page) (io.Reader, error) {
var templ tpl.Template
var found bool
templ, found = a.t.Lookup("alias.html")
if !found {
// TODO(bep) consolidate
templ, found = a.t.Lookup("_internal/alias.html")
if !found {
return nil, errors.New("no alias template found")
}
}
data := aliasPage{
permalink,
p,
}
ctx := tpl.SetPageInContext(context.Background(), p)
buffer := new(bytes.Buffer)
err := a.t.ExecuteWithContext(ctx, templ, buffer, data)
if err != nil {
return nil, err
}
return buffer, nil
}
func (s *Site) writeDestAlias(path, permalink string, outputFormat output.Format, p page.Page) (err error) {
return s.publishDestAlias(false, path, permalink, outputFormat, p)
}
func (s *Site) publishDestAlias(allowRoot bool, path, permalink string, outputFormat output.Format, p page.Page) (err error) {
handler := newAliasHandler(s.Tmpl(), s.Log, allowRoot)
targetPath, err := handler.targetPathAlias(path)
if err != nil {
return err
}
aliasContent, err := handler.renderAlias(permalink, p)
if err != nil {
return err
}
pd := publisher.Descriptor{
Src: aliasContent,
TargetPath: targetPath,
StatCounter: &s.PathSpec.ProcessingStats.Aliases,
OutputFormat: outputFormat,
}
if s.conf.RelativeURLs || s.conf.CanonifyURLs {
pd.AbsURLPath = s.absURLPath(targetPath)
}
return s.publisher.Publish(pd)
}
func (a aliasHandler) targetPathAlias(src string) (string, error) {
originalAlias := src
if len(src) <= 0 {
return "", fmt.Errorf("alias \"\" is an empty string")
}
alias := path.Clean(filepath.ToSlash(src))
if !a.allowRoot && alias == "/" {
return "", fmt.Errorf("alias \"%s\" resolves to website root directory", originalAlias)
}
components := strings.Split(alias, "/")
// Validate against directory traversal
if components[0] == ".." {
return "", fmt.Errorf("alias \"%s\" traverses outside the website root directory", originalAlias)
}
// Handle Windows file and directory naming restrictions
// See "Naming Files, Paths, and Namespaces" on MSDN
// https://msdn.microsoft.com/en-us/library/aa365247%28v=VS.85%29.aspx?f=255&MSPPError=-2147217396
msgs := []string{}
reservedNames := []string{"CON", "PRN", "AUX", "NUL", "COM0", "COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7", "COM8", "COM9", "LPT0", "LPT1", "LPT2", "LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9"}
if strings.ContainsAny(alias, ":*?\"<>|") {
msgs = append(msgs, fmt.Sprintf("Alias \"%s\" contains invalid characters on Windows: : * ? \" < > |", originalAlias))
}
for _, ch := range alias {
if ch < ' ' {
msgs = append(msgs, fmt.Sprintf("Alias \"%s\" contains ASCII control code (0x00 to 0x1F), invalid on Windows: : * ? \" < > |", originalAlias))
continue
}
}
for _, comp := range components {
if strings.HasSuffix(comp, " ") || strings.HasSuffix(comp, ".") {
msgs = append(msgs, fmt.Sprintf("Alias \"%s\" contains component with a trailing space or period, problematic on Windows", originalAlias))
}
for _, r := range reservedNames {
if comp == r {
msgs = append(msgs, fmt.Sprintf("Alias \"%s\" contains component with reserved name \"%s\" on Windows", originalAlias, r))
}
}
}
if len(msgs) > 0 {
if runtime.GOOS == "windows" {
for _, m := range msgs {
a.log.Errorln(m)
}
return "", fmt.Errorf("cannot create \"%s\": Windows filename restriction", originalAlias)
}
for _, m := range msgs {
a.log.Infoln(m)
}
}
// Add the final touch
alias = strings.TrimPrefix(alias, "/")
if strings.HasSuffix(alias, "/") {
alias = alias + "index.html"
} else if !strings.HasSuffix(alias, ".html") {
alias = alias + "/" + "index.html"
}
return filepath.FromSlash(alias), nil
}