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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 (
"fmt"
"net/http"
"os"
"time"
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/modules/caddyhttp"
)
func init() {
caddy.RegisterModule(caddy.Module{
Name: "http.matchers.file",
New: func() interface{} { return new(MatchFile) },
})
}
// MatchFile is an HTTP request matcher that can match
// requests based upon file existence.
type MatchFile struct {
// The root directory, used for creating absolute
// file paths, and required when working with
// relative paths; if not specified, the current
// directory is assumed. Accepts placeholders.
Root string `json:"root,omitempty"`
// The list of files to try. Each path here is
// considered relatice to Root. If nil, the
// request URL's path will be assumed. Accepts
// placeholders.
TryFiles []string `json:"try_files,omitempty"`
// How to choose a file in TryFiles.
// Default is first_exist.
TryPolicy string `json:"try_policy,omitempty"`
}
// Validate ensures m has a valid configuration.
func (m MatchFile) Validate() error {
switch m.TryPolicy {
case "",
tryPolicyFirstExist,
tryPolicyLargestSize,
tryPolicySmallestSize,
tryPolicyMostRecentMod:
default:
return fmt.Errorf("unknown try policy %s", m.TryPolicy)
}
return nil
}
// Match returns true if r matches m. Returns true
// if a file was matched. If so, two placeholders
// will be available:
// - http.matchers.file.relative
// - http.matchers.file.absolute
func (m MatchFile) Match(r *http.Request) bool {
repl := r.Context().Value(caddy.ReplacerCtxKey).(caddy.Replacer)
rel, abs, matched := m.selectFile(r)
if matched {
repl.Set("http.matchers.file.relative", rel)
repl.Set("http.matchers.file.absolute", abs)
}
return matched
}
// selectFile chooses a file according to m.TryPolicy by appending
// the paths in m.TryFiles to m.Root, with placeholder replacements.
// It returns the root-relative path to the matched file, the full
// or absolute path, and whether a match was made.
func (m MatchFile) selectFile(r *http.Request) (rel, abs string, matched bool) {
repl := r.Context().Value(caddy.ReplacerCtxKey).(caddy.Replacer)
root := repl.ReplaceAll(m.Root, "")
// if list of files to try was omitted entirely,
// assume URL path
if m.TryFiles == nil {
// m is not a pointer, so this is safe
m.TryFiles = []string{r.URL.Path}
}
switch m.TryPolicy {
case "", tryPolicyFirstExist:
for _, f := range m.TryFiles {
suffix := repl.ReplaceAll(f, "")
fullpath := sanitizedPathJoin(root, suffix)
if fileExists(fullpath) {
return suffix, fullpath, true
}
}
case tryPolicyLargestSize:
var largestSize int64
var largestFilename string
var largestSuffix string
for _, f := range m.TryFiles {
suffix := repl.ReplaceAll(f, "")
fullpath := sanitizedPathJoin(root, suffix)
info, err := os.Stat(fullpath)
if err == nil && info.Size() > largestSize {
largestSize = info.Size()
largestFilename = fullpath
largestSuffix = suffix
}
}
return largestSuffix, largestFilename, true
case tryPolicySmallestSize:
var smallestSize int64
var smallestFilename string
var smallestSuffix string
for _, f := range m.TryFiles {
suffix := repl.ReplaceAll(f, "")
fullpath := sanitizedPathJoin(root, suffix)
info, err := os.Stat(fullpath)
if err == nil && (smallestSize == 0 || info.Size() < smallestSize) {
smallestSize = info.Size()
smallestFilename = fullpath
smallestSuffix = suffix
}
}
return smallestSuffix, smallestFilename, true
case tryPolicyMostRecentMod:
var recentDate time.Time
var recentFilename string
var recentSuffix string
for _, f := range m.TryFiles {
suffix := repl.ReplaceAll(f, "")
fullpath := sanitizedPathJoin(root, suffix)
info, err := os.Stat(fullpath)
if err == nil &&
(recentDate.IsZero() || info.ModTime().After(recentDate)) {
recentDate = info.ModTime()
recentFilename = fullpath
recentSuffix = suffix
}
}
return recentSuffix, recentFilename, true
}
return
}
// fileExists returns true if file exists.
func fileExists(file string) bool {
_, err := os.Stat(file)
return !os.IsNotExist(err)
}
const (
tryPolicyFirstExist = "first_exist"
tryPolicyLargestSize = "largest_size"
tryPolicySmallestSize = "smallest_size"
tryPolicyMostRecentMod = "most_recent_modified"
)
// Interface guards
var (
_ caddy.Validator = (*MatchFile)(nil)
_ caddyhttp.RequestMatcher = (*MatchFile)(nil)
)
|
