mirror of
https://github.com/tinygo-org/net.git
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Add network device driver model, netdev
This PR adds a network device driver model called netdev. There will be a companion PR for TinyGo drivers to update the netdev drivers and network examples. This PR covers the core "net" package. An RFC for the work is here: #tinygo-org/drivers#487. Some things have changed from the RFC, but nothing major. The "net" package is a partial port of Go's "net" package, version 1.19.3. The src/net/README file has details on what is modified from Go's "net" package. Most "net" features are working as they would in normal Go. TCP/UDP/TLS protocol support is there. As well as HTTP client and server support. Standard Go network packages such as golang.org/x/net/websockets and Paho MQTT client work as-is. Other packages are likely to work as-is. Testing results are here (https://docs.google.com/spreadsheets/d/e/2PACX-1vT0cCjBvwXf9HJf6aJV2Sw198F2ief02gmbMV0sQocKT4y4RpfKv3dh6Jyew8lQW64FouZ8GwA2yjxI/pubhtml?gid=1013173032&single=true).
This commit is contained in:
Scott Feldman
committed by
deadprogram
deadprogram
parent
b46e2ec2ac
commit
693edae782
+974
@@ -0,0 +1,974 @@
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// TINYGO: The following is copied from Go 1.19.3 official implementation.
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// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// HTTP file system request handler
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package http
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import (
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"errors"
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"fmt"
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"io"
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"io/fs"
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"mime"
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"mime/multipart"
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"net/textproto"
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"net/url"
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"os"
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"path"
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"path/filepath"
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"sort"
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"strconv"
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"strings"
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"time"
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)
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// A Dir implements FileSystem using the native file system restricted to a
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// specific directory tree.
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//
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// While the FileSystem.Open method takes '/'-separated paths, a Dir's string
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// value is a filename on the native file system, not a URL, so it is separated
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// by filepath.Separator, which isn't necessarily '/'.
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//
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// Note that Dir could expose sensitive files and directories. Dir will follow
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// symlinks pointing out of the directory tree, which can be especially dangerous
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// if serving from a directory in which users are able to create arbitrary symlinks.
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// Dir will also allow access to files and directories starting with a period,
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// which could expose sensitive directories like .git or sensitive files like
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// .htpasswd. To exclude files with a leading period, remove the files/directories
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// from the server or create a custom FileSystem implementation.
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//
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// An empty Dir is treated as ".".
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type Dir string
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// mapOpenError maps the provided non-nil error from opening name
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// to a possibly better non-nil error. In particular, it turns OS-specific errors
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// about opening files in non-directories into fs.ErrNotExist. See Issues 18984 and 49552.
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func mapOpenError(originalErr error, name string, sep rune, stat func(string) (fs.FileInfo, error)) error {
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if errors.Is(originalErr, fs.ErrNotExist) || errors.Is(originalErr, fs.ErrPermission) {
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return originalErr
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}
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parts := strings.Split(name, string(sep))
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for i := range parts {
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if parts[i] == "" {
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continue
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}
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fi, err := stat(strings.Join(parts[:i+1], string(sep)))
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if err != nil {
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return originalErr
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}
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if !fi.IsDir() {
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return fs.ErrNotExist
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}
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}
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return originalErr
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}
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// Open implements FileSystem using os.Open, opening files for reading rooted
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// and relative to the directory d.
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func (d Dir) Open(name string) (File, error) {
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if filepath.Separator != '/' && strings.ContainsRune(name, filepath.Separator) {
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return nil, errors.New("http: invalid character in file path")
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}
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dir := string(d)
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if dir == "" {
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dir = "."
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}
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fullName := filepath.Join(dir, filepath.FromSlash(path.Clean("/"+name)))
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f, err := os.Open(fullName)
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if err != nil {
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return nil, mapOpenError(err, fullName, filepath.Separator, os.Stat)
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}
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return f, nil
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}
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// A FileSystem implements access to a collection of named files.
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// The elements in a file path are separated by slash ('/', U+002F)
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// characters, regardless of host operating system convention.
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// See the FileServer function to convert a FileSystem to a Handler.
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//
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// This interface predates the fs.FS interface, which can be used instead:
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// the FS adapter function converts an fs.FS to a FileSystem.
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type FileSystem interface {
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Open(name string) (File, error)
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}
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// A File is returned by a FileSystem's Open method and can be
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// served by the FileServer implementation.
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//
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// The methods should behave the same as those on an *os.File.
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type File interface {
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io.Closer
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io.Reader
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io.Seeker
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Readdir(count int) ([]fs.FileInfo, error)
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Stat() (fs.FileInfo, error)
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}
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type anyDirs interface {
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len() int
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name(i int) string
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isDir(i int) bool
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}
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type fileInfoDirs []fs.FileInfo
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func (d fileInfoDirs) len() int { return len(d) }
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func (d fileInfoDirs) isDir(i int) bool { return d[i].IsDir() }
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func (d fileInfoDirs) name(i int) string { return d[i].Name() }
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type dirEntryDirs []fs.DirEntry
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func (d dirEntryDirs) len() int { return len(d) }
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func (d dirEntryDirs) isDir(i int) bool { return d[i].IsDir() }
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func (d dirEntryDirs) name(i int) string { return d[i].Name() }
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func dirList(w ResponseWriter, r *Request, f File) {
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// Prefer to use ReadDir instead of Readdir,
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// because the former doesn't require calling
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// Stat on every entry of a directory on Unix.
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var dirs anyDirs
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var err error
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if d, ok := f.(fs.ReadDirFile); ok {
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var list dirEntryDirs
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list, err = d.ReadDir(-1)
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dirs = list
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} else {
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var list fileInfoDirs
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list, err = f.Readdir(-1)
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dirs = list
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}
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if err != nil {
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logf(r, "http: error reading directory: %v", err)
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Error(w, "Error reading directory", StatusInternalServerError)
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return
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}
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sort.Slice(dirs, func(i, j int) bool { return dirs.name(i) < dirs.name(j) })
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w.Header().Set("Content-Type", "text/html; charset=utf-8")
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fmt.Fprintf(w, "<pre>\n")
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for i, n := 0, dirs.len(); i < n; i++ {
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name := dirs.name(i)
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if dirs.isDir(i) {
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name += "/"
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}
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// name may contain '?' or '#', which must be escaped to remain
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// part of the URL path, and not indicate the start of a query
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// string or fragment.
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url := url.URL{Path: name}
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fmt.Fprintf(w, "<a href=\"%s\">%s</a>\n", url.String(), htmlReplacer.Replace(name))
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}
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fmt.Fprintf(w, "</pre>\n")
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}
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// ServeContent replies to the request using the content in the
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// provided ReadSeeker. The main benefit of ServeContent over io.Copy
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// is that it handles Range requests properly, sets the MIME type, and
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// handles If-Match, If-Unmodified-Since, If-None-Match, If-Modified-Since,
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// and If-Range requests.
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//
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// If the response's Content-Type header is not set, ServeContent
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// first tries to deduce the type from name's file extension and,
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// if that fails, falls back to reading the first block of the content
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// and passing it to DetectContentType.
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// The name is otherwise unused; in particular it can be empty and is
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// never sent in the response.
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//
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// If modtime is not the zero time or Unix epoch, ServeContent
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// includes it in a Last-Modified header in the response. If the
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// request includes an If-Modified-Since header, ServeContent uses
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// modtime to decide whether the content needs to be sent at all.
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//
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// The content's Seek method must work: ServeContent uses
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// a seek to the end of the content to determine its size.
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//
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// If the caller has set w's ETag header formatted per RFC 7232, section 2.3,
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// ServeContent uses it to handle requests using If-Match, If-None-Match, or If-Range.
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//
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// Note that *os.File implements the io.ReadSeeker interface.
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func ServeContent(w ResponseWriter, req *Request, name string, modtime time.Time, content io.ReadSeeker) {
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sizeFunc := func() (int64, error) {
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size, err := content.Seek(0, io.SeekEnd)
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if err != nil {
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return 0, errSeeker
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}
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_, err = content.Seek(0, io.SeekStart)
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if err != nil {
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return 0, errSeeker
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}
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return size, nil
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}
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serveContent(w, req, name, modtime, sizeFunc, content)
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}
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// errSeeker is returned by ServeContent's sizeFunc when the content
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// doesn't seek properly. The underlying Seeker's error text isn't
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// included in the sizeFunc reply so it's not sent over HTTP to end
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// users.
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var errSeeker = errors.New("seeker can't seek")
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// errNoOverlap is returned by serveContent's parseRange if first-byte-pos of
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// all of the byte-range-spec values is greater than the content size.
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var errNoOverlap = errors.New("invalid range: failed to overlap")
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// if name is empty, filename is unknown. (used for mime type, before sniffing)
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// if modtime.IsZero(), modtime is unknown.
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// content must be seeked to the beginning of the file.
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// The sizeFunc is called at most once. Its error, if any, is sent in the HTTP response.
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func serveContent(w ResponseWriter, r *Request, name string, modtime time.Time, sizeFunc func() (int64, error), content io.ReadSeeker) {
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setLastModified(w, modtime)
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done, rangeReq := checkPreconditions(w, r, modtime)
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if done {
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return
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}
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code := StatusOK
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// If Content-Type isn't set, use the file's extension to find it, but
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// if the Content-Type is unset explicitly, do not sniff the type.
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ctypes, haveType := w.Header()["Content-Type"]
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var ctype string
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if !haveType {
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ctype = mime.TypeByExtension(filepath.Ext(name))
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if ctype == "" {
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// read a chunk to decide between utf-8 text and binary
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var buf [sniffLen]byte
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n, _ := io.ReadFull(content, buf[:])
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ctype = DetectContentType(buf[:n])
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_, err := content.Seek(0, io.SeekStart) // rewind to output whole file
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if err != nil {
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Error(w, "seeker can't seek", StatusInternalServerError)
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return
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}
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}
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w.Header().Set("Content-Type", ctype)
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} else if len(ctypes) > 0 {
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ctype = ctypes[0]
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}
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size, err := sizeFunc()
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if err != nil {
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Error(w, err.Error(), StatusInternalServerError)
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return
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}
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// handle Content-Range header.
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sendSize := size
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var sendContent io.Reader = content
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if size >= 0 {
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ranges, err := parseRange(rangeReq, size)
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if err != nil {
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if err == errNoOverlap {
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w.Header().Set("Content-Range", fmt.Sprintf("bytes */%d", size))
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}
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Error(w, err.Error(), StatusRequestedRangeNotSatisfiable)
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return
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}
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if sumRangesSize(ranges) > size {
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// The total number of bytes in all the ranges
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// is larger than the size of the file by
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// itself, so this is probably an attack, or a
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// dumb client. Ignore the range request.
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ranges = nil
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}
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switch {
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case len(ranges) == 1:
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// RFC 7233, Section 4.1:
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// "If a single part is being transferred, the server
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// generating the 206 response MUST generate a
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// Content-Range header field, describing what range
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// of the selected representation is enclosed, and a
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// payload consisting of the range.
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// ...
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// A server MUST NOT generate a multipart response to
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// a request for a single range, since a client that
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// does not request multiple parts might not support
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// multipart responses."
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ra := ranges[0]
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if _, err := content.Seek(ra.start, io.SeekStart); err != nil {
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Error(w, err.Error(), StatusRequestedRangeNotSatisfiable)
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return
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}
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sendSize = ra.length
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code = StatusPartialContent
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w.Header().Set("Content-Range", ra.contentRange(size))
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case len(ranges) > 1:
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sendSize = rangesMIMESize(ranges, ctype, size)
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code = StatusPartialContent
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pr, pw := io.Pipe()
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mw := multipart.NewWriter(pw)
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w.Header().Set("Content-Type", "multipart/byteranges; boundary="+mw.Boundary())
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sendContent = pr
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defer pr.Close() // cause writing goroutine to fail and exit if CopyN doesn't finish.
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go func() {
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for _, ra := range ranges {
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part, err := mw.CreatePart(ra.mimeHeader(ctype, size))
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if err != nil {
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pw.CloseWithError(err)
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return
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}
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if _, err := content.Seek(ra.start, io.SeekStart); err != nil {
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pw.CloseWithError(err)
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return
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}
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if _, err := io.CopyN(part, content, ra.length); err != nil {
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pw.CloseWithError(err)
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return
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}
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}
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mw.Close()
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pw.Close()
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}()
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}
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w.Header().Set("Accept-Ranges", "bytes")
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if w.Header().Get("Content-Encoding") == "" {
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w.Header().Set("Content-Length", strconv.FormatInt(sendSize, 10))
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}
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}
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w.WriteHeader(code)
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if r.Method != "HEAD" {
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io.CopyN(w, sendContent, sendSize)
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}
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}
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// scanETag determines if a syntactically valid ETag is present at s. If so,
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// the ETag and remaining text after consuming ETag is returned. Otherwise,
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// it returns "", "".
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func scanETag(s string) (etag string, remain string) {
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s = textproto.TrimString(s)
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start := 0
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if strings.HasPrefix(s, "W/") {
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start = 2
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}
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if len(s[start:]) < 2 || s[start] != '"' {
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return "", ""
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}
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// ETag is either W/"text" or "text".
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// See RFC 7232 2.3.
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for i := start + 1; i < len(s); i++ {
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c := s[i]
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switch {
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// Character values allowed in ETags.
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case c == 0x21 || c >= 0x23 && c <= 0x7E || c >= 0x80:
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case c == '"':
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return s[:i+1], s[i+1:]
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default:
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return "", ""
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}
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}
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return "", ""
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}
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// etagStrongMatch reports whether a and b match using strong ETag comparison.
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// Assumes a and b are valid ETags.
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func etagStrongMatch(a, b string) bool {
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return a == b && a != "" && a[0] == '"'
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}
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// etagWeakMatch reports whether a and b match using weak ETag comparison.
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// Assumes a and b are valid ETags.
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func etagWeakMatch(a, b string) bool {
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return strings.TrimPrefix(a, "W/") == strings.TrimPrefix(b, "W/")
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}
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// condResult is the result of an HTTP request precondition check.
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// See https://tools.ietf.org/html/rfc7232 section 3.
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type condResult int
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const (
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condNone condResult = iota
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condTrue
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condFalse
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)
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func checkIfMatch(w ResponseWriter, r *Request) condResult {
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im := r.Header.Get("If-Match")
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if im == "" {
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return condNone
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}
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for {
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im = textproto.TrimString(im)
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if len(im) == 0 {
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break
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}
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if im[0] == ',' {
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im = im[1:]
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continue
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}
|
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if im[0] == '*' {
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return condTrue
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}
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etag, remain := scanETag(im)
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if etag == "" {
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break
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||||
}
|
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if etagStrongMatch(etag, w.Header().get("Etag")) {
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return condTrue
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}
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im = remain
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}
|
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|
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return condFalse
|
||||
}
|
||||
|
||||
func checkIfUnmodifiedSince(r *Request, modtime time.Time) condResult {
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ius := r.Header.Get("If-Unmodified-Since")
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if ius == "" || isZeroTime(modtime) {
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return condNone
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||||
}
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t, err := ParseTime(ius)
|
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if err != nil {
|
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return condNone
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}
|
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|
||||
// The Last-Modified header truncates sub-second precision so
|
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// the modtime needs to be truncated too.
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modtime = modtime.Truncate(time.Second)
|
||||
if modtime.Before(t) || modtime.Equal(t) {
|
||||
return condTrue
|
||||
}
|
||||
return condFalse
|
||||
}
|
||||
|
||||
func checkIfNoneMatch(w ResponseWriter, r *Request) condResult {
|
||||
inm := r.Header.get("If-None-Match")
|
||||
if inm == "" {
|
||||
return condNone
|
||||
}
|
||||
buf := inm
|
||||
for {
|
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buf = textproto.TrimString(buf)
|
||||
if len(buf) == 0 {
|
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break
|
||||
}
|
||||
if buf[0] == ',' {
|
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buf = buf[1:]
|
||||
continue
|
||||
}
|
||||
if buf[0] == '*' {
|
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return condFalse
|
||||
}
|
||||
etag, remain := scanETag(buf)
|
||||
if etag == "" {
|
||||
break
|
||||
}
|
||||
if etagWeakMatch(etag, w.Header().get("Etag")) {
|
||||
return condFalse
|
||||
}
|
||||
buf = remain
|
||||
}
|
||||
return condTrue
|
||||
}
|
||||
|
||||
func checkIfModifiedSince(r *Request, modtime time.Time) condResult {
|
||||
if r.Method != "GET" && r.Method != "HEAD" {
|
||||
return condNone
|
||||
}
|
||||
ims := r.Header.Get("If-Modified-Since")
|
||||
if ims == "" || isZeroTime(modtime) {
|
||||
return condNone
|
||||
}
|
||||
t, err := ParseTime(ims)
|
||||
if err != nil {
|
||||
return condNone
|
||||
}
|
||||
// The Last-Modified header truncates sub-second precision so
|
||||
// the modtime needs to be truncated too.
|
||||
modtime = modtime.Truncate(time.Second)
|
||||
if modtime.Before(t) || modtime.Equal(t) {
|
||||
return condFalse
|
||||
}
|
||||
return condTrue
|
||||
}
|
||||
|
||||
func checkIfRange(w ResponseWriter, r *Request, modtime time.Time) condResult {
|
||||
if r.Method != "GET" && r.Method != "HEAD" {
|
||||
return condNone
|
||||
}
|
||||
ir := r.Header.get("If-Range")
|
||||
if ir == "" {
|
||||
return condNone
|
||||
}
|
||||
etag, _ := scanETag(ir)
|
||||
if etag != "" {
|
||||
if etagStrongMatch(etag, w.Header().Get("Etag")) {
|
||||
return condTrue
|
||||
} else {
|
||||
return condFalse
|
||||
}
|
||||
}
|
||||
// The If-Range value is typically the ETag value, but it may also be
|
||||
// the modtime date. See golang.org/issue/8367.
|
||||
if modtime.IsZero() {
|
||||
return condFalse
|
||||
}
|
||||
t, err := ParseTime(ir)
|
||||
if err != nil {
|
||||
return condFalse
|
||||
}
|
||||
if t.Unix() == modtime.Unix() {
|
||||
return condTrue
|
||||
}
|
||||
return condFalse
|
||||
}
|
||||
|
||||
var unixEpochTime = time.Unix(0, 0)
|
||||
|
||||
// isZeroTime reports whether t is obviously unspecified (either zero or Unix()=0).
|
||||
func isZeroTime(t time.Time) bool {
|
||||
return t.IsZero() || t.Equal(unixEpochTime)
|
||||
}
|
||||
|
||||
func setLastModified(w ResponseWriter, modtime time.Time) {
|
||||
if !isZeroTime(modtime) {
|
||||
w.Header().Set("Last-Modified", modtime.UTC().Format(TimeFormat))
|
||||
}
|
||||
}
|
||||
|
||||
func writeNotModified(w ResponseWriter) {
|
||||
// RFC 7232 section 4.1:
|
||||
// a sender SHOULD NOT generate representation metadata other than the
|
||||
// above listed fields unless said metadata exists for the purpose of
|
||||
// guiding cache updates (e.g., Last-Modified might be useful if the
|
||||
// response does not have an ETag field).
|
||||
h := w.Header()
|
||||
delete(h, "Content-Type")
|
||||
delete(h, "Content-Length")
|
||||
delete(h, "Content-Encoding")
|
||||
if h.Get("Etag") != "" {
|
||||
delete(h, "Last-Modified")
|
||||
}
|
||||
w.WriteHeader(StatusNotModified)
|
||||
}
|
||||
|
||||
// checkPreconditions evaluates request preconditions and reports whether a precondition
|
||||
// resulted in sending StatusNotModified or StatusPreconditionFailed.
|
||||
func checkPreconditions(w ResponseWriter, r *Request, modtime time.Time) (done bool, rangeHeader string) {
|
||||
// This function carefully follows RFC 7232 section 6.
|
||||
ch := checkIfMatch(w, r)
|
||||
if ch == condNone {
|
||||
ch = checkIfUnmodifiedSince(r, modtime)
|
||||
}
|
||||
if ch == condFalse {
|
||||
w.WriteHeader(StatusPreconditionFailed)
|
||||
return true, ""
|
||||
}
|
||||
switch checkIfNoneMatch(w, r) {
|
||||
case condFalse:
|
||||
if r.Method == "GET" || r.Method == "HEAD" {
|
||||
writeNotModified(w)
|
||||
return true, ""
|
||||
} else {
|
||||
w.WriteHeader(StatusPreconditionFailed)
|
||||
return true, ""
|
||||
}
|
||||
case condNone:
|
||||
if checkIfModifiedSince(r, modtime) == condFalse {
|
||||
writeNotModified(w)
|
||||
return true, ""
|
||||
}
|
||||
}
|
||||
|
||||
rangeHeader = r.Header.get("Range")
|
||||
if rangeHeader != "" && checkIfRange(w, r, modtime) == condFalse {
|
||||
rangeHeader = ""
|
||||
}
|
||||
return false, rangeHeader
|
||||
}
|
||||
|
||||
// name is '/'-separated, not filepath.Separator.
|
||||
func serveFile(w ResponseWriter, r *Request, fs FileSystem, name string, redirect bool) {
|
||||
const indexPage = "/index.html"
|
||||
|
||||
// redirect .../index.html to .../
|
||||
// can't use Redirect() because that would make the path absolute,
|
||||
// which would be a problem running under StripPrefix
|
||||
if strings.HasSuffix(r.URL.Path, indexPage) {
|
||||
localRedirect(w, r, "./")
|
||||
return
|
||||
}
|
||||
|
||||
f, err := fs.Open(name)
|
||||
if err != nil {
|
||||
msg, code := toHTTPError(err)
|
||||
Error(w, msg, code)
|
||||
return
|
||||
}
|
||||
defer f.Close()
|
||||
|
||||
d, err := f.Stat()
|
||||
if err != nil {
|
||||
msg, code := toHTTPError(err)
|
||||
Error(w, msg, code)
|
||||
return
|
||||
}
|
||||
|
||||
if redirect {
|
||||
// redirect to canonical path: / at end of directory url
|
||||
// r.URL.Path always begins with /
|
||||
url := r.URL.Path
|
||||
if d.IsDir() {
|
||||
if url[len(url)-1] != '/' {
|
||||
localRedirect(w, r, path.Base(url)+"/")
|
||||
return
|
||||
}
|
||||
} else {
|
||||
if url[len(url)-1] == '/' {
|
||||
localRedirect(w, r, "../"+path.Base(url))
|
||||
return
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if d.IsDir() {
|
||||
url := r.URL.Path
|
||||
// redirect if the directory name doesn't end in a slash
|
||||
if url == "" || url[len(url)-1] != '/' {
|
||||
localRedirect(w, r, path.Base(url)+"/")
|
||||
return
|
||||
}
|
||||
|
||||
// use contents of index.html for directory, if present
|
||||
index := strings.TrimSuffix(name, "/") + indexPage
|
||||
ff, err := fs.Open(index)
|
||||
if err == nil {
|
||||
defer ff.Close()
|
||||
dd, err := ff.Stat()
|
||||
if err == nil {
|
||||
name = index
|
||||
d = dd
|
||||
f = ff
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Still a directory? (we didn't find an index.html file)
|
||||
if d.IsDir() {
|
||||
if checkIfModifiedSince(r, d.ModTime()) == condFalse {
|
||||
writeNotModified(w)
|
||||
return
|
||||
}
|
||||
setLastModified(w, d.ModTime())
|
||||
dirList(w, r, f)
|
||||
return
|
||||
}
|
||||
|
||||
// serveContent will check modification time
|
||||
sizeFunc := func() (int64, error) { return d.Size(), nil }
|
||||
serveContent(w, r, d.Name(), d.ModTime(), sizeFunc, f)
|
||||
}
|
||||
|
||||
// toHTTPError returns a non-specific HTTP error message and status code
|
||||
// for a given non-nil error value. It's important that toHTTPError does not
|
||||
// actually return err.Error(), since msg and httpStatus are returned to users,
|
||||
// and historically Go's ServeContent always returned just "404 Not Found" for
|
||||
// all errors. We don't want to start leaking information in error messages.
|
||||
func toHTTPError(err error) (msg string, httpStatus int) {
|
||||
if errors.Is(err, fs.ErrNotExist) {
|
||||
return "404 page not found", StatusNotFound
|
||||
}
|
||||
if errors.Is(err, fs.ErrPermission) {
|
||||
return "403 Forbidden", StatusForbidden
|
||||
}
|
||||
// Default:
|
||||
return "500 Internal Server Error", StatusInternalServerError
|
||||
}
|
||||
|
||||
// localRedirect gives a Moved Permanently response.
|
||||
// It does not convert relative paths to absolute paths like Redirect does.
|
||||
func localRedirect(w ResponseWriter, r *Request, newPath string) {
|
||||
if q := r.URL.RawQuery; q != "" {
|
||||
newPath += "?" + q
|
||||
}
|
||||
w.Header().Set("Location", newPath)
|
||||
w.WriteHeader(StatusMovedPermanently)
|
||||
}
|
||||
|
||||
// ServeFile replies to the request with the contents of the named
|
||||
// file or directory.
|
||||
//
|
||||
// If the provided file or directory name is a relative path, it is
|
||||
// interpreted relative to the current directory and may ascend to
|
||||
// parent directories. If the provided name is constructed from user
|
||||
// input, it should be sanitized before calling ServeFile.
|
||||
//
|
||||
// As a precaution, ServeFile will reject requests where r.URL.Path
|
||||
// contains a ".." path element; this protects against callers who
|
||||
// might unsafely use filepath.Join on r.URL.Path without sanitizing
|
||||
// it and then use that filepath.Join result as the name argument.
|
||||
//
|
||||
// As another special case, ServeFile redirects any request where r.URL.Path
|
||||
// ends in "/index.html" to the same path, without the final
|
||||
// "index.html". To avoid such redirects either modify the path or
|
||||
// use ServeContent.
|
||||
//
|
||||
// Outside of those two special cases, ServeFile does not use
|
||||
// r.URL.Path for selecting the file or directory to serve; only the
|
||||
// file or directory provided in the name argument is used.
|
||||
func ServeFile(w ResponseWriter, r *Request, name string) {
|
||||
if containsDotDot(r.URL.Path) {
|
||||
// Too many programs use r.URL.Path to construct the argument to
|
||||
// serveFile. Reject the request under the assumption that happened
|
||||
// here and ".." may not be wanted.
|
||||
// Note that name might not contain "..", for example if code (still
|
||||
// incorrectly) used filepath.Join(myDir, r.URL.Path).
|
||||
Error(w, "invalid URL path", StatusBadRequest)
|
||||
return
|
||||
}
|
||||
dir, file := filepath.Split(name)
|
||||
serveFile(w, r, Dir(dir), file, false)
|
||||
}
|
||||
|
||||
func containsDotDot(v string) bool {
|
||||
if !strings.Contains(v, "..") {
|
||||
return false
|
||||
}
|
||||
for _, ent := range strings.FieldsFunc(v, isSlashRune) {
|
||||
if ent == ".." {
|
||||
return true
|
||||
}
|
||||
}
|
||||
return false
|
||||
}
|
||||
|
||||
func isSlashRune(r rune) bool { return r == '/' || r == '\\' }
|
||||
|
||||
type fileHandler struct {
|
||||
root FileSystem
|
||||
}
|
||||
|
||||
type ioFS struct {
|
||||
fsys fs.FS
|
||||
}
|
||||
|
||||
type ioFile struct {
|
||||
file fs.File
|
||||
}
|
||||
|
||||
func (f ioFS) Open(name string) (File, error) {
|
||||
if name == "/" {
|
||||
name = "."
|
||||
} else {
|
||||
name = strings.TrimPrefix(name, "/")
|
||||
}
|
||||
file, err := f.fsys.Open(name)
|
||||
if err != nil {
|
||||
return nil, mapOpenError(err, name, '/', func(path string) (fs.FileInfo, error) {
|
||||
return fs.Stat(f.fsys, path)
|
||||
})
|
||||
}
|
||||
return ioFile{file}, nil
|
||||
}
|
||||
|
||||
func (f ioFile) Close() error { return f.file.Close() }
|
||||
func (f ioFile) Read(b []byte) (int, error) { return f.file.Read(b) }
|
||||
func (f ioFile) Stat() (fs.FileInfo, error) { return f.file.Stat() }
|
||||
|
||||
var errMissingSeek = errors.New("io.File missing Seek method")
|
||||
var errMissingReadDir = errors.New("io.File directory missing ReadDir method")
|
||||
|
||||
func (f ioFile) Seek(offset int64, whence int) (int64, error) {
|
||||
s, ok := f.file.(io.Seeker)
|
||||
if !ok {
|
||||
return 0, errMissingSeek
|
||||
}
|
||||
return s.Seek(offset, whence)
|
||||
}
|
||||
|
||||
func (f ioFile) ReadDir(count int) ([]fs.DirEntry, error) {
|
||||
d, ok := f.file.(fs.ReadDirFile)
|
||||
if !ok {
|
||||
return nil, errMissingReadDir
|
||||
}
|
||||
return d.ReadDir(count)
|
||||
}
|
||||
|
||||
func (f ioFile) Readdir(count int) ([]fs.FileInfo, error) {
|
||||
d, ok := f.file.(fs.ReadDirFile)
|
||||
if !ok {
|
||||
return nil, errMissingReadDir
|
||||
}
|
||||
var list []fs.FileInfo
|
||||
for {
|
||||
dirs, err := d.ReadDir(count - len(list))
|
||||
for _, dir := range dirs {
|
||||
info, err := dir.Info()
|
||||
if err != nil {
|
||||
// Pretend it doesn't exist, like (*os.File).Readdir does.
|
||||
continue
|
||||
}
|
||||
list = append(list, info)
|
||||
}
|
||||
if err != nil {
|
||||
return list, err
|
||||
}
|
||||
if count < 0 || len(list) >= count {
|
||||
break
|
||||
}
|
||||
}
|
||||
return list, nil
|
||||
}
|
||||
|
||||
// FS converts fsys to a FileSystem implementation,
|
||||
// for use with FileServer and NewFileTransport.
|
||||
func FS(fsys fs.FS) FileSystem {
|
||||
return ioFS{fsys}
|
||||
}
|
||||
|
||||
// FileServer returns a handler that serves HTTP requests
|
||||
// with the contents of the file system rooted at root.
|
||||
//
|
||||
// As a special case, the returned file server redirects any request
|
||||
// ending in "/index.html" to the same path, without the final
|
||||
// "index.html".
|
||||
//
|
||||
// To use the operating system's file system implementation,
|
||||
// use http.Dir:
|
||||
//
|
||||
// http.Handle("/", http.FileServer(http.Dir("/tmp")))
|
||||
//
|
||||
// To use an fs.FS implementation, use http.FS to convert it:
|
||||
//
|
||||
// http.Handle("/", http.FileServer(http.FS(fsys)))
|
||||
func FileServer(root FileSystem) Handler {
|
||||
return &fileHandler{root}
|
||||
}
|
||||
|
||||
func (f *fileHandler) ServeHTTP(w ResponseWriter, r *Request) {
|
||||
upath := r.URL.Path
|
||||
if !strings.HasPrefix(upath, "/") {
|
||||
upath = "/" + upath
|
||||
r.URL.Path = upath
|
||||
}
|
||||
serveFile(w, r, f.root, path.Clean(upath), true)
|
||||
}
|
||||
|
||||
// httpRange specifies the byte range to be sent to the client.
|
||||
type httpRange struct {
|
||||
start, length int64
|
||||
}
|
||||
|
||||
func (r httpRange) contentRange(size int64) string {
|
||||
return fmt.Sprintf("bytes %d-%d/%d", r.start, r.start+r.length-1, size)
|
||||
}
|
||||
|
||||
func (r httpRange) mimeHeader(contentType string, size int64) textproto.MIMEHeader {
|
||||
return textproto.MIMEHeader{
|
||||
"Content-Range": {r.contentRange(size)},
|
||||
"Content-Type": {contentType},
|
||||
}
|
||||
}
|
||||
|
||||
// parseRange parses a Range header string as per RFC 7233.
|
||||
// errNoOverlap is returned if none of the ranges overlap.
|
||||
func parseRange(s string, size int64) ([]httpRange, error) {
|
||||
if s == "" {
|
||||
return nil, nil // header not present
|
||||
}
|
||||
const b = "bytes="
|
||||
if !strings.HasPrefix(s, b) {
|
||||
return nil, errors.New("invalid range")
|
||||
}
|
||||
var ranges []httpRange
|
||||
noOverlap := false
|
||||
for _, ra := range strings.Split(s[len(b):], ",") {
|
||||
ra = textproto.TrimString(ra)
|
||||
if ra == "" {
|
||||
continue
|
||||
}
|
||||
start, end, ok := strings.Cut(ra, "-")
|
||||
if !ok {
|
||||
return nil, errors.New("invalid range")
|
||||
}
|
||||
start, end = textproto.TrimString(start), textproto.TrimString(end)
|
||||
var r httpRange
|
||||
if start == "" {
|
||||
// If no start is specified, end specifies the
|
||||
// range start relative to the end of the file,
|
||||
// and we are dealing with <suffix-length>
|
||||
// which has to be a non-negative integer as per
|
||||
// RFC 7233 Section 2.1 "Byte-Ranges".
|
||||
if end == "" || end[0] == '-' {
|
||||
return nil, errors.New("invalid range")
|
||||
}
|
||||
i, err := strconv.ParseInt(end, 10, 64)
|
||||
if i < 0 || err != nil {
|
||||
return nil, errors.New("invalid range")
|
||||
}
|
||||
if i > size {
|
||||
i = size
|
||||
}
|
||||
r.start = size - i
|
||||
r.length = size - r.start
|
||||
} else {
|
||||
i, err := strconv.ParseInt(start, 10, 64)
|
||||
if err != nil || i < 0 {
|
||||
return nil, errors.New("invalid range")
|
||||
}
|
||||
if i >= size {
|
||||
// If the range begins after the size of the content,
|
||||
// then it does not overlap.
|
||||
noOverlap = true
|
||||
continue
|
||||
}
|
||||
r.start = i
|
||||
if end == "" {
|
||||
// If no end is specified, range extends to end of the file.
|
||||
r.length = size - r.start
|
||||
} else {
|
||||
i, err := strconv.ParseInt(end, 10, 64)
|
||||
if err != nil || r.start > i {
|
||||
return nil, errors.New("invalid range")
|
||||
}
|
||||
if i >= size {
|
||||
i = size - 1
|
||||
}
|
||||
r.length = i - r.start + 1
|
||||
}
|
||||
}
|
||||
ranges = append(ranges, r)
|
||||
}
|
||||
if noOverlap && len(ranges) == 0 {
|
||||
// The specified ranges did not overlap with the content.
|
||||
return nil, errNoOverlap
|
||||
}
|
||||
return ranges, nil
|
||||
}
|
||||
|
||||
// countingWriter counts how many bytes have been written to it.
|
||||
type countingWriter int64
|
||||
|
||||
func (w *countingWriter) Write(p []byte) (n int, err error) {
|
||||
*w += countingWriter(len(p))
|
||||
return len(p), nil
|
||||
}
|
||||
|
||||
// rangesMIMESize returns the number of bytes it takes to encode the
|
||||
// provided ranges as a multipart response.
|
||||
func rangesMIMESize(ranges []httpRange, contentType string, contentSize int64) (encSize int64) {
|
||||
var w countingWriter
|
||||
mw := multipart.NewWriter(&w)
|
||||
for _, ra := range ranges {
|
||||
mw.CreatePart(ra.mimeHeader(contentType, contentSize))
|
||||
encSize += ra.length
|
||||
}
|
||||
mw.Close()
|
||||
encSize += int64(w)
|
||||
return
|
||||
}
|
||||
|
||||
func sumRangesSize(ranges []httpRange) (size int64) {
|
||||
for _, ra := range ranges {
|
||||
size += ra.length
|
||||
}
|
||||
return
|
||||
}
|
||||
Reference in New Issue
Block a user