// NewFileReader returns a new FileReader reading the contents of fileBlobRef,
// fetching blobs from fetcher. The fileBlobRef must be of a "bytes" or "file"
// schema blob.
//
// The caller should call Close on the FileReader when done reading.
func NewFileReader(fetcher blob.Fetcher, fileBlobRef blob.Ref) (*FileReader, error) {
// TODO(bradfitz): rename this into bytes reader? but for now it's still
// named FileReader, but can also read a "bytes" schema.
if !fileBlobRef.Valid() {
return nil, errors.New("schema/filereader: NewFileReader blobref invalid")
}
rc, _, err := fetcher.Fetch(fileBlobRef)
if err != nil {
return nil, fmt.Errorf("schema/filereader: fetching file schema blob: %v", err)
}
defer rc.Close()
ss, err := parseSuperset(rc)
if err != nil {
return nil, fmt.Errorf("schema/filereader: decoding file schema blob: %v", err)
}
ss.BlobRef = fileBlobRef
if ss.Type != "file" && ss.Type != "bytes" {
return nil, fmt.Errorf("schema/filereader: expected \"file\" or \"bytes\" schema blob, got %q", ss.Type)
}
fr, err := ss.NewFileReader(fetcher)
if err != nil {
return nil, fmt.Errorf("schema/filereader: creating FileReader for %s: %v", fileBlobRef, err)
}
return fr, nil
}
func copyBlob(br blob.Ref, dst blobserver.BlobReceiver, src blob.Fetcher) error {
rc, _, err := src.Fetch(br)
if err != nil {
return err
}
defer rc.Close()
_, err = dst.ReceiveBlob(br, rc)
return err
}
func fetch(src blob.Fetcher, br blob.Ref) (r io.ReadCloser, err error) {
if *flagVerbose {
log.Printf("Fetching %s", br.String())
}
r, _, err = src.Fetch(br)
if err != nil {
return nil, fmt.Errorf("Failed to fetch %s: %s", br, err)
}
return r, err
}
func slurpBlob(t *testing.T, sto blob.Fetcher, br blob.Ref) []byte {
rc, _, err := sto.Fetch(br)
if err != nil {
t.Fatal(err)
}
defer rc.Close()
slurp, err := ioutil.ReadAll(rc)
if err != nil {
t.Fatal(err)
}
return slurp
}
func (ss *superset) setFromBlobRef(fetcher blob.Fetcher, blobRef blob.Ref) error {
if !blobRef.Valid() {
return errors.New("schema/dirreader: blobref invalid")
}
ss.BlobRef = blobRef
rc, _, err := fetcher.Fetch(blobRef)
if err != nil {
return fmt.Errorf("schema/dirreader: fetching schema blob %s: %v", blobRef, err)
}
defer rc.Close()
if err := json.NewDecoder(rc).Decode(ss); err != nil {
return fmt.Errorf("schema/dirreader: decoding schema blob %s: %v", blobRef, err)
}
return nil
}
func schemaFromBlobRef(bs blob.Fetcher, ref string) (*schema.Blob, error) {
br, ok := blob.Parse(ref)
if !ok {
return nil, fmt.Errorf("%q: unparseable blob ref")
}
body, _, err := bs.Fetch(br)
if err != nil {
// TODO(dichro): delete this from index?
return nil, fmt.Errorf("%s: previously indexed; now missing", br)
}
s, ok := parseSchema(br, body)
body.Close()
if !ok {
return nil, fmt.Errorf("%s: previously schema; now unparseable", br)
}
return s, nil
}
func printHierarchy(fsck *db.DB, bs blob.Fetcher, depth int, suffix string, nodes []string) {
prefix := ""
for i := 0; i < depth; i++ {
prefix = prefix + " "
}
for _, node := range nodes {
nextSuffix := suffix
ref := blob.MustParse(node)
camliType := "unknown"
if body, _, err := bs.Fetch(ref); err != nil {
camliType = fmt.Sprintf("Fetch(): %s", err)
} else {
if s, ok := parseSchema(ref, body); ok {
fileName := s.FileName()
switch t := s.Type(); t {
case "file":
// this blob is a "file" that just happens to contain a
// camlistore blob in its contents. This happens because I
// may have camput my blobs directory once or twice :P
if len(suffix) > 0 {
nextSuffix = fmt.Sprintf("%s -> %s", fileName, nextSuffix)
} else {
nextSuffix = fileName
}
camliType = fmt.Sprintf("%s: %q", t, nextSuffix)
case "directory":
nextSuffix = fmt.Sprintf("%s/%s", fileName, suffix)
camliType = fmt.Sprintf("%s: %q", t, nextSuffix)
default:
camliType = t
}
}
body.Close()
}
switch next, err := fsck.Parents(node); {
case err != nil:
fmt.Printf("%s* %s: %s\n", prefix, node, err)
case len(next) == 0:
fmt.Printf("%s- %s (%s)\n", prefix, node, camliType)
default:
fmt.Printf("%s+ %s (%s)\n", prefix, node, camliType)
printHierarchy(fsck, bs, depth+1, nextSuffix, next)
}
}
}
// ServeBlobRef serves a blob.
func ServeBlobRef(rw http.ResponseWriter, req *http.Request, blobRef blob.Ref, fetcher blob.Fetcher) {
rc, size, err := fetcher.Fetch(blobRef)
switch err {
case nil:
break
case os.ErrNotExist:
rw.WriteHeader(http.StatusNotFound)
fmt.Fprintf(rw, "Blob %q not found", blobRef)
return
default:
httputil.ServeError(rw, req, err)
return
}
defer rc.Close()
rw.Header().Set("Content-Type", "application/octet-stream")
var content io.ReadSeeker = readerutil.NewFakeSeeker(rc, int64(size))
rangeHeader := req.Header.Get("Range") != ""
const small = 32 << 10
var b *blob.Blob
if rangeHeader || size < small {
// Slurp to memory, so we can actually seek on it (for Range support),
// or if we're going to be showing it in the browser (below).
b, err = blob.FromReader(blobRef, rc, size)
if err != nil {
httputil.ServeError(rw, req, err)
return
}
content = b.Open()
}
if !rangeHeader && size < small {
// If it's small and all UTF-8, assume it's text and
// just render it in the browser. This is more for
// demos/debuggability than anything else. It isn't
// part of the spec.
if b.IsUTF8() {
rw.Header().Set("Content-Type", "text/plain; charset=utf-8")
}
}
http.ServeContent(rw, req, "", dummyModTime, content)
}
// Unauthenticated user. Be paranoid.
func handleGetViaSharing(conn http.ResponseWriter, req *http.Request,
blobRef blob.Ref, fetcher blob.Fetcher) error {
if !httputil.IsGet(req) {
return &shareError{code: invalidMethod, response: badRequest, message: "Invalid method"}
}
conn.Header().Set("Access-Control-Allow-Origin", "*")
viaPathOkay := false
startTime := time.Now()
defer func() {
if !viaPathOkay {
// Insert a delay, to hide timing attacks probing
// for the existence of blobs.
sleep := fetchFailureDelay - (time.Now().Sub(startTime))
time.Sleep(sleep)
}
}()
viaBlobs := make([]blob.Ref, 0)
if via := req.FormValue("via"); via != "" {
for _, vs := range strings.Split(via, ",") {
if br, ok := blob.Parse(vs); ok {
viaBlobs = append(viaBlobs, br)
} else {
return &shareError{code: invalidVia, response: badRequest, message: "Malformed blobref in via param"}
}
}
}
fetchChain := make([]blob.Ref, 0)
fetchChain = append(fetchChain, viaBlobs...)
fetchChain = append(fetchChain, blobRef)
isTransitive := false
for i, br := range fetchChain {
switch i {
case 0:
file, size, err := fetcher.Fetch(br)
if err != nil {
return unauthorized(shareFetchFailed, "Fetch chain 0 of %s failed: %v", br, err)
}
defer file.Close()
if size > schema.MaxSchemaBlobSize {
return unauthorized(shareBlobTooLarge, "Fetch chain 0 of %s too large", br)
}
blob, err := schema.BlobFromReader(br, file)
if err != nil {
return unauthorized(shareReadFailed, "Can't create a blob from %v: %v", br, err)
}
share, ok := blob.AsShare()
if !ok {
return unauthorized(shareBlobInvalid, "Fetch chain 0 of %s wasn't a valid Share", br)
}
if share.IsExpired() {
return unauthorized(shareExpired, "Share is expired")
}
if len(fetchChain) > 1 && fetchChain[1].String() != share.Target().String() {
return unauthorized(shareTargetInvalid,
"Fetch chain 0->1 (%s -> %q) unauthorized, expected hop to %q",
br, fetchChain[1], share.Target())
}
isTransitive = share.IsTransitive()
if len(fetchChain) > 2 && !isTransitive {
return unauthorized(shareNotTransitive, "Share is not transitive")
}
case len(fetchChain) - 1:
// Last one is fine (as long as its path up to here has been proven, and it's
// not the first thing in the chain)
continue
default:
file, _, err := fetcher.Fetch(br)
if err != nil {
return unauthorized(viaChainFetchFailed, "Fetch chain %d of %s failed: %v", i, br, err)
}
defer file.Close()
lr := io.LimitReader(file, schema.MaxSchemaBlobSize)
slurpBytes, err := ioutil.ReadAll(lr)
if err != nil {
return unauthorized(viaChainReadFailed,
"Fetch chain %d of %s failed in slurp: %v", i, br, err)
}
saught := fetchChain[i+1].String()
if bytes.Index(slurpBytes, []byte(saught)) == -1 {
return unauthorized(viaChainInvalidLink,
"Fetch chain %d of %s failed; no reference to %s", i, br, saught)
}
}
}
if assemble, _ := strconv.ParseBool(req.FormValue("assemble")); assemble {
if !isTransitive {
return unauthorized(assembleNonTransitive, "Cannot assemble non-transitive share")
}
dh := &DownloadHandler{
Fetcher: fetcher,
// TODO(aa): It would be nice to specify a local cache here, as the UI handler does.
}
dh.ServeHTTP(conn, req, blobRef)
} else {
gethandler.ServeBlobRef(conn, req, blobRef, fetcher)
}
viaPathOkay = true
return nil
}
