hugo/target/htmlredirect.go
Bjørn Erik Pedersen 4f66f790b1 Add readFile template func
This also includes a refactor of the hugofs package and its usage.

The motivation for that is:

The Afero filesystems are brilliant. Hugo's way of adding a dozen of global variables for the different filesystems was a mistake. In readFile (and also in some other places in Hugo today) we need a way to restrict the access inside the working dir. We could use ioutil.ReadFile and implement the path checking, checking the base path and the dots ("..") etc. But it is obviously better to use an Afero BasePathFs combined witha ReadOnlyFs. We could create a use-once-filesystem and handle the initialization ourselves, but since this is also useful to others and the initialization depends on some other global state (which would mean to create a new file system on every invocation), we might as well do it properly and encapsulate the predefined set of filesystems. This change also leads the way, if needed, to encapsulate the file systems in a struct, making it possible to have several file system sets in action at once (parallel multilanguage site building? With Moore's law and all...)

Fixes #1551
2016-03-31 21:24:18 +02:00

149 lines
4.8 KiB
Go

// 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 = "<!DOCTYPE html><html><head><link rel=\"canonical\" href=\"{{ .Permalink }}\"/><meta http-equiv=\"content-type\" content=\"text/html; charset=utf-8\" /><meta http-equiv=\"refresh\" content=\"0;url={{ .Permalink }}\" /></head></html>"
const aliasXHtml = "<!DOCTYPE html><html xmlns=\"http://www.w3.org/1999/xhtml\"><head><link rel=\"canonical\" href=\"{{ .Permalink }}\"/><meta http-equiv=\"content-type\" content=\"text/html; charset=utf-8\" /><meta http-equiv=\"refresh\" content=\"0;url={{ .Permalink }}\" /></head></html>"
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())
}