// Copyright 2016 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 target
import (
"bytes"
"fmt"
"html/template"
"path/filepath"
"runtime"
"strings"
"github.com/spf13/hugo/helpers"
"github.com/spf13/hugo/hugofs"
jww "github.com/spf13/jwalterweatherman"
)
const alias = "{{ .Permalink }}"
const aliasXHtml = "{{ .Permalink }}"
var defaultAliasTemplates *template.Template
func init() {
defaultAliasTemplates = template.New("")
template.Must(defaultAliasTemplates.New("alias").Parse(alias))
template.Must(defaultAliasTemplates.New("alias-xhtml").Parse(aliasXHtml))
}
type AliasPublisher interface {
Translator
Publish(string, string) error
}
type HTMLRedirectAlias struct {
PublishDir string
Templates *template.Template
}
func (h *HTMLRedirectAlias) Translate(alias string) (aliasPath string, err error) {
originalAlias := alias
if len(alias) <= 0 {
return "", fmt.Errorf("Alias \"\" is an empty string")
}
alias = filepath.Clean(alias)
components := strings.Split(alias, helpers.FilePathSeparator)
if alias == helpers.FilePathSeparator {
return "", fmt.Errorf("Alias \"%s\" resolves to website root directory", originalAlias)
}
// 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", "COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7", "COM8", "COM9", "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 {
jww.ERROR.Println(m)
}
return "", fmt.Errorf("Cannot create \"%s\": Windows filename restriction", originalAlias)
}
for _, m := range msgs {
jww.WARN.Println(m)
}
}
// Add the final touch
if strings.HasPrefix(alias, helpers.FilePathSeparator) {
alias = alias[1:]
}
if strings.HasSuffix(alias, helpers.FilePathSeparator) {
alias = alias + "index.html"
} else if !strings.HasSuffix(alias, ".html") {
alias = alias + helpers.FilePathSeparator + "index.html"
}
if originalAlias != alias {
jww.INFO.Printf("Alias \"%s\" translated to \"%s\"\n", originalAlias, alias)
}
return filepath.Join(h.PublishDir, alias), nil
}
type AliasNode struct {
Permalink string
}
func (h *HTMLRedirectAlias) Publish(path string, permalink string) (err error) {
if path, err = h.Translate(path); err != nil {
jww.ERROR.Printf("%s, skipping.", err)
return nil
}
t := "alias"
if strings.HasSuffix(path, ".xhtml") {
t = "alias-xhtml"
}
template := defaultAliasTemplates
if h.Templates != nil {
template = h.Templates
}
buffer := new(bytes.Buffer)
err = template.ExecuteTemplate(buffer, t, &AliasNode{permalink})
if err != nil {
return
}
return helpers.WriteToDisk(path, buffer, hugofs.Destination())
}