// bytesHaveSchemaLink reports whether bb is a valid Camlistore schema
// blob and has target somewhere in a schema field used to represent a
// Merkle-tree-ish file or directory.
func bytesHaveSchemaLink(br blob.Ref, bb []byte, target blob.Ref) bool {
// Fast path for no:
if !bytes.Contains(bb, []byte(target.String())) {
return false
}
b, err := schema.BlobFromReader(br, bytes.NewReader(bb))
if err != nil {
return false
}
typ := b.Type()
switch typ {
case "file", "blob":
for _, bp := range b.ByteParts() {
if bp.BlobRef.Valid() {
return bp.BlobRef == target
}
if bp.BytesRef.Valid() {
return bp.BytesRef == target
}
}
case "directory":
if d, ok := b.DirectoryEntries(); ok {
return d == target
}
case "static-set":
for _, m := range b.StaticSetMembers() {
if m == target {
return true
}
}
}
return false
}
func NewFromShareRoot(shareBlobURL string) (c *Client, target *blobref.BlobRef, err error) {
var root string
if m := shareURLRx.FindStringSubmatch(shareBlobURL); m == nil {
return nil, nil, fmt.Errorf("Unkown URL base; doesn't contain /camli/")
} else {
c = New(m[1])
c.discoOnce.Do(func() { /* nothing */
})
c.prefixOnce.Do(func() { /* nothing */
})
c.prefixv = m[1]
c.authMode = auth.None{}
c.via = make(map[string]string)
root = m[2]
}
res, err := http.Get(shareBlobURL)
if err != nil {
return nil, nil, fmt.Errorf("Error fetching %s: %v", shareBlobURL, err)
}
defer res.Body.Close()
blob, err := schema.BlobFromReader(blobref.Parse(root), res.Body)
if err != nil {
return nil, nil, fmt.Errorf("Error parsing JSON from %s: %v", shareBlobURL, err)
}
if blob.ShareAuthType() != "haveref" {
return nil, nil, fmt.Errorf("Unknown share authType of %q", blob.ShareAuthType())
}
target = blob.ShareTarget()
if target == nil {
return nil, nil, fmt.Errorf("No target.")
}
c.via[target.String()] = root
return c, target, nil
}
func (c *Client) FetchSchemaBlob(b blob.Ref) (*schema.Blob, error) {
rc, _, err := c.Fetch(b)
if err != nil {
return nil, err
}
defer rc.Close()
return schema.BlobFromReader(b, rc)
}
func isSchemaPicker(thenSto, elseSto blobserver.Storage) storageFunc {
return func(br blob.Ref, src io.Reader) (dest blobserver.Storage, newSrc io.Reader, err error) {
var buf bytes.Buffer
blob, err := schema.BlobFromReader(br, io.TeeReader(src, &buf))
newSrc = io.MultiReader(bytes.NewReader(buf.Bytes()), src)
if err != nil || blob.Type() == "" {
return elseSto, newSrc, nil
}
return thenSto, newSrc, nil
}
}
func isSchemaPicker(thenSto, elseSto blobserver.Storage) storageFunc {
return func(src io.Reader) (dest blobserver.Storage, overRead []byte, err error) {
var buf bytes.Buffer
tee := io.TeeReader(src, &buf)
blob, err := schema.BlobFromReader(dummyRef, tee)
if err != nil || blob.Type() == "" {
return elseSto, buf.Bytes(), nil
}
return thenSto, buf.Bytes(), nil
}
}
func (sn *BlobSniffer) bufferIsCamliJSON() bool {
buf := sn.header
if !schema.LikelySchemaBlob(buf) {
return false
}
blob, err := schema.BlobFromReader(sn.br, bytes.NewReader(buf))
if err != nil {
return false
}
sn.meta = blob
return true
}
// NewFromShareRoot uses shareBlobURL to set up and return a client that
// will be used to fetch shared blobs.
func NewFromShareRoot(shareBlobURL string, opts ...ClientOption) (c *Client, target blob.Ref, err error) {
var root string
m := shareURLRx.FindStringSubmatch(shareBlobURL)
if m == nil {
return nil, blob.Ref{}, fmt.Errorf("Unkown share URL base")
}
c = New(m[1])
c.discoOnce.Do(func() { /* nothing */
})
c.prefixOnce.Do(func() { /* nothing */
})
c.prefixv = m[1]
c.isSharePrefix = true
c.authMode = auth.None{}
c.via = make(map[string]string)
root = m[2]
for _, v := range opts {
v.modifyClient(c)
}
c.SetHTTPClient(&http.Client{Transport: c.TransportForConfig(nil)})
req := c.newRequest("GET", shareBlobURL, nil)
res, err := c.doReqGated(req)
if err != nil {
return nil, blob.Ref{}, fmt.Errorf("Error fetching %s: %v", shareBlobURL, err)
}
defer res.Body.Close()
b, err := schema.BlobFromReader(blob.ParseOrZero(root), res.Body)
if err != nil {
return nil, blob.Ref{}, fmt.Errorf("Error parsing JSON from %s: %v", shareBlobURL, err)
}
if b.ShareAuthType() != schema.ShareHaveRef {
return nil, blob.Ref{}, fmt.Errorf("Unknown share authType of %q", b.ShareAuthType())
}
target = b.ShareTarget()
if !target.Valid() {
return nil, blob.Ref{}, fmt.Errorf("No target.")
}
c.via[target.String()] = root
return c, target, nil
}
// NewFromShareRoot uses shareBlobURL to set up and return a client that
// will be used to fetch shared blobs.
func NewFromShareRoot(shareBlobURL string, opts ...ClientOption) (c *Client, target blob.Ref, err error) {
var root string
m := shareURLRx.FindStringSubmatch(shareBlobURL)
if m == nil {
return nil, blob.Ref{}, fmt.Errorf("Unkown share URL base")
}
c = New(m[1], opts...)
c.discoOnce.Do(noop)
c.prefixOnce.Do(noop)
c.prefixv = m[1]
c.isSharePrefix = true
c.authMode = auth.None{}
c.via = make(map[blob.Ref]blob.Ref)
root = m[2]
req := c.newRequest("GET", shareBlobURL, nil)
res, err := c.expect2XX(req)
if err != nil {
return nil, blob.Ref{}, fmt.Errorf("error fetching %s: %v", shareBlobURL, err)
}
defer res.Body.Close()
var buf bytes.Buffer
rootbr, ok := blob.Parse(root)
if !ok {
return nil, blob.Ref{}, fmt.Errorf("invalid root blob ref for sharing: %q", root)
}
b, err := schema.BlobFromReader(rootbr, io.TeeReader(res.Body, &buf))
if err != nil {
return nil, blob.Ref{}, fmt.Errorf("error parsing JSON from %s: %v , with response: %q", shareBlobURL, err, buf.Bytes())
}
if b.ShareAuthType() != schema.ShareHaveRef {
return nil, blob.Ref{}, fmt.Errorf("unknown share authType of %q", b.ShareAuthType())
}
target = b.ShareTarget()
if !target.Valid() {
return nil, blob.Ref{}, fmt.Errorf("no target.")
}
c.via[target] = rootbr
return c, target, nil
}
// cached returns a FileReader for the given blobref, which may
// point to either a blob representing the entire thumbnail (max
// 16MB) or a file schema blob.
//
// The ReadCloser should be closed when done reading.
func (ih *ImageHandler) cached(br blob.Ref) (io.ReadCloser, error) {
rsc, _, err := ih.Cache.FetchStreaming(br)
if err != nil {
return nil, err
}
slurp, err := ioutil.ReadAll(rsc)
rsc.Close()
if err != nil {
return nil, err
}
// In the common case, when the scaled image itself is less than 16 MB, it's
// all together in one blob.
if strings.HasPrefix(magic.MIMEType(slurp), "image/") {
thumbCacheHitFull.Add(1)
if imageDebug {
log.Printf("Image Cache: hit: %v\n", br)
}
return ioutil.NopCloser(bytes.NewReader(slurp)), nil
}
// For large scaled images, the cached blob is a file schema blob referencing
// the sub-chunks.
fileBlob, err := schema.BlobFromReader(br, bytes.NewReader(slurp))
if err != nil {
log.Printf("Failed to parse non-image thumbnail cache blob %v: %v", br, err)
return nil, err
}
fetchSeeker := blob.SeekerFromStreamingFetcher(ih.Cache)
fr, err := fileBlob.NewFileReader(fetchSeeker)
if err != nil {
log.Printf("cached(%d) NewFileReader = %v", br, err)
return nil, err
}
thumbCacheHitFile.Add(1)
if imageDebug {
log.Printf("Image Cache: fileref hit: %v\n", br)
}
return fr, nil
}
func (s *storage) ReceiveBlob(br blob.Ref, source io.Reader) (sb blob.SizedRef, err error) {
buf := pools.BytesBuffer()
defer pools.PutBuffer(buf)
if _, err := io.Copy(buf, source); err != nil {
return sb, err
}
size := uint32(buf.Len())
isFile := false
fileBlob, err := schema.BlobFromReader(br, bytes.NewReader(buf.Bytes()))
if err == nil && fileBlob.Type() == "file" {
isFile = true
}
meta, err := s.getMetaRow(br)
if err != nil {
return sb, err
}
if meta.exists {
sb = blob.SizedRef{Size: size, Ref: br}
} else {
sb, err = s.small.ReceiveBlob(br, buf)
if err != nil {
return sb, err
}
}
if !isFile || meta.isPacked() || fileBlob.PartsSize() < packThreshold {
return sb, nil
}
// Pack the blob.
s.packGate.Start()
defer s.packGate.Done()
// We ignore the return value from packFile since we can't
// really recover. At least be happy that we have all the
// data on 'small' already. packFile will log at least.
s.packFile(br)
return sb, nil
}
// Errors returned are:
// os.ErrNotExist -- blob not found
// os.ErrInvalid -- not JSON or a camli schema blob
func (fs *CamliFileSystem) fetchSchemaMeta(br blob.Ref) (*schema.Blob, error) {
blobStr := br.String()
if blob, ok := fs.blobToSchema.Get(blobStr); ok {
return blob.(*schema.Blob), nil
}
rc, _, err := fs.fetcher.Fetch(br)
if err != nil {
return nil, err
}
defer rc.Close()
blob, err := schema.BlobFromReader(br, rc)
if err != nil {
log.Printf("Error parsing %s as schema blob: %v", br, err)
return nil, os.ErrInvalid
}
if blob.Type() == "" {
log.Printf("blob %s is JSON but lacks camliType", br)
return nil, os.ErrInvalid
}
fs.blobToSchema.Add(blobStr, blob)
return blob, nil
}
// Unauthenticated user. Be paranoid.
func handleGetViaSharing(conn http.ResponseWriter, req *http.Request,
blobRef blob.Ref, fetcher blob.StreamingFetcher) error {
if !httputil.IsGet(req) {
return &shareError{code: invalidMethod, response: badRequest, message: "Invalid method"}
}
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.FetchStreaming(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.FetchStreaming(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
}
// Unauthenticated user. Be paranoid.
func handleGetViaSharing(conn http.ResponseWriter, req *http.Request,
blobRef blob.Ref, fetcher blob.StreamingFetcher) {
if req.Method != "GET" && req.Method != "HEAD" {
httputil.BadRequestError(conn, "Invalid method")
return
}
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 {
httputil.BadRequestError(conn, "Malformed blobref in via param")
return
}
}
}
fetchChain := make([]blob.Ref, 0)
fetchChain = append(fetchChain, viaBlobs...)
fetchChain = append(fetchChain, blobRef)
for i, br := range fetchChain {
switch i {
case 0:
file, size, err := fetcher.FetchStreaming(br)
if err != nil {
log.Printf("Fetch chain 0 of %s failed: %v", br.String(), err)
auth.SendUnauthorized(conn, req)
return
}
defer file.Close()
if size > schema.MaxSchemaBlobSize {
log.Printf("Fetch chain 0 of %s too large", br.String())
auth.SendUnauthorized(conn, req)
return
}
blob, err := schema.BlobFromReader(br, file)
if err != nil {
log.Printf("Can't create a blob from %v: %v", br.String(), err)
auth.SendUnauthorized(conn, req)
return
}
share, ok := blob.AsShare()
if !ok {
log.Printf("Fetch chain 0 of %s wasn't a valid Share", br.String())
auth.SendUnauthorized(conn, req)
return
}
if len(fetchChain) > 1 && fetchChain[1].String() != share.Target().String() {
log.Printf("Fetch chain 0->1 (%s -> %q) unauthorized, expected hop to %q",
br.String(), fetchChain[1].String(), share.Target().String())
auth.SendUnauthorized(conn, req)
return
}
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.FetchStreaming(br)
if err != nil {
log.Printf("Fetch chain %d of %s failed: %v", i, br.String(), err)
auth.SendUnauthorized(conn, req)
return
}
defer file.Close()
lr := io.LimitReader(file, schema.MaxSchemaBlobSize)
slurpBytes, err := ioutil.ReadAll(lr)
if err != nil {
log.Printf("Fetch chain %d of %s failed in slurp: %v", i, br.String(), err)
auth.SendUnauthorized(conn, req)
return
}
saught := fetchChain[i+1].String()
if bytes.IndexAny(slurpBytes, saught) == -1 {
log.Printf("Fetch chain %d of %s failed; no reference to %s",
i, br.String(), saught)
auth.SendUnauthorized(conn, req)
return
}
}
}
viaPathOkay = true
gethandler.ServeBlobRef(conn, req, blobRef, fetcher)
}
