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Diffstat (limited to 'src/pkg/net/http/fs.go')
| -rw-r--r-- | src/pkg/net/http/fs.go | 552 |
1 files changed, 0 insertions, 552 deletions
diff --git a/src/pkg/net/http/fs.go b/src/pkg/net/http/fs.go deleted file mode 100644 index bae902cd2..000000000 --- a/src/pkg/net/http/fs.go +++ /dev/null @@ -1,552 +0,0 @@ -// Copyright 2009 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// HTTP file system request handler - -package http - -import ( - "errors" - "fmt" - "io" - "mime" - "mime/multipart" - "net/textproto" - "net/url" - "os" - "path" - "path/filepath" - "strconv" - "strings" - "time" -) - -// A Dir implements http.FileSystem using the native file -// system restricted to a specific directory tree. -// -// An empty Dir is treated as ".". -type Dir string - -func (d Dir) Open(name string) (File, error) { - if filepath.Separator != '/' && strings.IndexRune(name, filepath.Separator) >= 0 || - strings.Contains(name, "\x00") { - return nil, errors.New("http: invalid character in file path") - } - dir := string(d) - if dir == "" { - dir = "." - } - f, err := os.Open(filepath.Join(dir, filepath.FromSlash(path.Clean("/"+name)))) - if err != nil { - return nil, err - } - return f, nil -} - -// A FileSystem implements access to a collection of named files. -// The elements in a file path are separated by slash ('/', U+002F) -// characters, regardless of host operating system convention. -type FileSystem interface { - Open(name string) (File, error) -} - -// A File is returned by a FileSystem's Open method and can be -// served by the FileServer implementation. -// -// The methods should behave the same as those on an *os.File. -type File interface { - io.Closer - io.Reader - Readdir(count int) ([]os.FileInfo, error) - Seek(offset int64, whence int) (int64, error) - Stat() (os.FileInfo, error) -} - -func dirList(w ResponseWriter, f File) { - w.Header().Set("Content-Type", "text/html; charset=utf-8") - fmt.Fprintf(w, "<pre>\n") - for { - dirs, err := f.Readdir(100) - if err != nil || len(dirs) == 0 { - break - } - for _, d := range dirs { - name := d.Name() - if d.IsDir() { - name += "/" - } - // name may contain '?' or '#', which must be escaped to remain - // part of the URL path, and not indicate the start of a query - // string or fragment. - url := url.URL{Path: name} - fmt.Fprintf(w, "<a href=\"%s\">%s</a>\n", url.String(), htmlReplacer.Replace(name)) - } - } - fmt.Fprintf(w, "</pre>\n") -} - -// ServeContent replies to the request using the content in the -// provided ReadSeeker. The main benefit of ServeContent over io.Copy -// is that it handles Range requests properly, sets the MIME type, and -// handles If-Modified-Since requests. -// -// If the response's Content-Type header is not set, ServeContent -// first tries to deduce the type from name's file extension and, -// if that fails, falls back to reading the first block of the content -// and passing it to DetectContentType. -// The name is otherwise unused; in particular it can be empty and is -// never sent in the response. -// -// If modtime is not the zero time, ServeContent includes it in a -// Last-Modified header in the response. If the request includes an -// If-Modified-Since header, ServeContent uses modtime to decide -// whether the content needs to be sent at all. -// -// The content's Seek method must work: ServeContent uses -// a seek to the end of the content to determine its size. -// -// If the caller has set w's ETag header, ServeContent uses it to -// handle requests using If-Range and If-None-Match. -// -// Note that *os.File implements the io.ReadSeeker interface. -func ServeContent(w ResponseWriter, req *Request, name string, modtime time.Time, content io.ReadSeeker) { - sizeFunc := func() (int64, error) { - size, err := content.Seek(0, os.SEEK_END) - if err != nil { - return 0, errSeeker - } - _, err = content.Seek(0, os.SEEK_SET) - if err != nil { - return 0, errSeeker - } - return size, nil - } - serveContent(w, req, name, modtime, sizeFunc, content) -} - -// errSeeker is returned by ServeContent's sizeFunc when the content -// doesn't seek properly. The underlying Seeker's error text isn't -// included in the sizeFunc reply so it's not sent over HTTP to end -// users. -var errSeeker = errors.New("seeker can't seek") - -// if name is empty, filename is unknown. (used for mime type, before sniffing) -// if modtime.IsZero(), modtime is unknown. -// content must be seeked to the beginning of the file. -// The sizeFunc is called at most once. Its error, if any, is sent in the HTTP response. -func serveContent(w ResponseWriter, r *Request, name string, modtime time.Time, sizeFunc func() (int64, error), content io.ReadSeeker) { - if checkLastModified(w, r, modtime) { - return - } - rangeReq, done := checkETag(w, r, modtime) - if done { - return - } - - code := StatusOK - - // If Content-Type isn't set, use the file's extension to find it, but - // if the Content-Type is unset explicitly, do not sniff the type. - ctypes, haveType := w.Header()["Content-Type"] - var ctype string - if !haveType { - ctype = mime.TypeByExtension(filepath.Ext(name)) - if ctype == "" { - // read a chunk to decide between utf-8 text and binary - var buf [sniffLen]byte - n, _ := io.ReadFull(content, buf[:]) - ctype = DetectContentType(buf[:n]) - _, err := content.Seek(0, os.SEEK_SET) // rewind to output whole file - if err != nil { - Error(w, "seeker can't seek", StatusInternalServerError) - return - } - } - w.Header().Set("Content-Type", ctype) - } else if len(ctypes) > 0 { - ctype = ctypes[0] - } - - size, err := sizeFunc() - if err != nil { - Error(w, err.Error(), StatusInternalServerError) - return - } - - // handle Content-Range header. - sendSize := size - var sendContent io.Reader = content - if size >= 0 { - ranges, err := parseRange(rangeReq, size) - if err != nil { - Error(w, err.Error(), StatusRequestedRangeNotSatisfiable) - return - } - if sumRangesSize(ranges) > size { - // The total number of bytes in all the ranges - // is larger than the size of the file by - // itself, so this is probably an attack, or a - // dumb client. Ignore the range request. - ranges = nil - } - switch { - case len(ranges) == 1: - // RFC 2616, Section 14.16: - // "When an HTTP message includes the content of a single - // range (for example, a response to a request for a - // single range, or to a request for a set of ranges - // that overlap without any holes), this content is - // transmitted with a Content-Range header, and a - // Content-Length header showing the number of bytes - // actually transferred. - // ... - // A response to a request for a single range MUST NOT - // be sent using the multipart/byteranges media type." - ra := ranges[0] - if _, err := content.Seek(ra.start, os.SEEK_SET); err != nil { - Error(w, err.Error(), StatusRequestedRangeNotSatisfiable) - return - } - sendSize = ra.length - code = StatusPartialContent - w.Header().Set("Content-Range", ra.contentRange(size)) - case len(ranges) > 1: - sendSize = rangesMIMESize(ranges, ctype, size) - code = StatusPartialContent - - pr, pw := io.Pipe() - mw := multipart.NewWriter(pw) - w.Header().Set("Content-Type", "multipart/byteranges; boundary="+mw.Boundary()) - sendContent = pr - defer pr.Close() // cause writing goroutine to fail and exit if CopyN doesn't finish. - go func() { - for _, ra := range ranges { - part, err := mw.CreatePart(ra.mimeHeader(ctype, size)) - if err != nil { - pw.CloseWithError(err) - return - } - if _, err := content.Seek(ra.start, os.SEEK_SET); err != nil { - pw.CloseWithError(err) - return - } - if _, err := io.CopyN(part, content, ra.length); err != nil { - pw.CloseWithError(err) - return - } - } - mw.Close() - pw.Close() - }() - } - - w.Header().Set("Accept-Ranges", "bytes") - if w.Header().Get("Content-Encoding") == "" { - w.Header().Set("Content-Length", strconv.FormatInt(sendSize, 10)) - } - } - - w.WriteHeader(code) - - if r.Method != "HEAD" { - io.CopyN(w, sendContent, sendSize) - } -} - -// modtime is the modification time of the resource to be served, or IsZero(). -// return value is whether this request is now complete. -func checkLastModified(w ResponseWriter, r *Request, modtime time.Time) bool { - if modtime.IsZero() { - return false - } - - // The Date-Modified header truncates sub-second precision, so - // use mtime < t+1s instead of mtime <= t to check for unmodified. - if t, err := time.Parse(TimeFormat, r.Header.Get("If-Modified-Since")); err == nil && modtime.Before(t.Add(1*time.Second)) { - h := w.Header() - delete(h, "Content-Type") - delete(h, "Content-Length") - w.WriteHeader(StatusNotModified) - return true - } - w.Header().Set("Last-Modified", modtime.UTC().Format(TimeFormat)) - return false -} - -// checkETag implements If-None-Match and If-Range checks. -// -// The ETag or modtime must have been previously set in the -// ResponseWriter's headers. The modtime is only compared at second -// granularity and may be the zero value to mean unknown. -// -// The return value is the effective request "Range" header to use and -// whether this request is now considered done. -func checkETag(w ResponseWriter, r *Request, modtime time.Time) (rangeReq string, done bool) { - etag := w.Header().get("Etag") - rangeReq = r.Header.get("Range") - - // Invalidate the range request if the entity doesn't match the one - // the client was expecting. - // "If-Range: version" means "ignore the Range: header unless version matches the - // current file." - // We only support ETag versions. - // The caller must have set the ETag on the response already. - if ir := r.Header.get("If-Range"); ir != "" && ir != etag { - // The If-Range value is typically the ETag value, but it may also be - // the modtime date. See golang.org/issue/8367. - timeMatches := false - if !modtime.IsZero() { - if t, err := ParseTime(ir); err == nil && t.Unix() == modtime.Unix() { - timeMatches = true - } - } - if !timeMatches { - rangeReq = "" - } - } - - if inm := r.Header.get("If-None-Match"); inm != "" { - // Must know ETag. - if etag == "" { - return rangeReq, false - } - - // TODO(bradfitz): non-GET/HEAD requests require more work: - // sending a different status code on matches, and - // also can't use weak cache validators (those with a "W/ - // prefix). But most users of ServeContent will be using - // it on GET or HEAD, so only support those for now. - if r.Method != "GET" && r.Method != "HEAD" { - return rangeReq, false - } - - // TODO(bradfitz): deal with comma-separated or multiple-valued - // list of If-None-match values. For now just handle the common - // case of a single item. - if inm == etag || inm == "*" { - h := w.Header() - delete(h, "Content-Type") - delete(h, "Content-Length") - w.WriteHeader(StatusNotModified) - return "", true - } - } - return rangeReq, false -} - -// 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 { - // TODO expose actual error? - NotFound(w, r) - return - } - defer f.Close() - - d, err1 := f.Stat() - if err1 != nil { - // TODO expose actual error? - NotFound(w, r) - 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 - } - } - } - - // use contents of index.html for directory, if present - if d.IsDir() { - index := 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 checkLastModified(w, r, d.ModTime()) { - return - } - dirList(w, f) - return - } - - // serveContent will check modification time - sizeFunc := func() (int64, error) { return d.Size(), nil } - serveContent(w, r, d.Name(), d.ModTime(), sizeFunc, f) -} - -// 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. -func ServeFile(w ResponseWriter, r *Request, name string) { - dir, file := filepath.Split(name) - serveFile(w, r, Dir(dir), file, false) -} - -type fileHandler struct { - root FileSystem -} - -// FileServer returns a handler that serves HTTP requests -// with the contents of the file system rooted at root. -// -// To use the operating system's file system implementation, -// use http.Dir: -// -// http.Handle("/", http.FileServer(http.Dir("/tmp"))) -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 2616. -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 - for _, ra := range strings.Split(s[len(b):], ",") { - ra = strings.TrimSpace(ra) - if ra == "" { - continue - } - i := strings.Index(ra, "-") - if i < 0 { - return nil, errors.New("invalid range") - } - start, end := strings.TrimSpace(ra[:i]), strings.TrimSpace(ra[i+1:]) - var r httpRange - if start == "" { - // If no start is specified, end specifies the - // range start relative to the end of the file. - i, err := strconv.ParseInt(end, 10, 64) - if 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 > size || i < 0 { - return nil, errors.New("invalid range") - } - 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) - } - 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 -} |