Merge pull request #2341 from stevvooe/limit-payload-size-26

[release/2.6] registry/{storage,handlers}: limit content sizes

registry/handlers/blobupload.go

@@ -179,8 +179,8 @@ func (buh *blobUploadHandler) PatchBlobData(w http.ResponseWriter, r *http.Reque
 
 	// TODO(dmcgowan): support Content-Range header to seek and write range
 
-	if err := copyFullPayload(w, r, buh.Upload, buh, "blob PATCH", &buh.Errors); err != nil {
+	if err := copyFullPayload(w, r, buh.Upload, -1, buh, "blob PATCH"); err != nil {
-		// copyFullPayload reports the error if necessary
+		buh.Errors = append(buh.Errors, errcode.ErrorCodeUnknown.WithDetail(err.Error()))
 		return
 	}
 
@@ -218,8 +218,8 @@ func (buh *blobUploadHandler) PutBlobUploadComplete(w http.ResponseWriter, r *ht
 		return
 	}
 
-	if err := copyFullPayload(w, r, buh.Upload, buh, "blob PUT", &buh.Errors); err != nil {
+	if err := copyFullPayload(w, r, buh.Upload, -1, buh, "blob PUT"); err != nil {
-		// copyFullPayload reports the error if necessary
+		buh.Errors = append(buh.Errors, errcode.ErrorCodeUnknown.WithDetail(err.Error()))
 		return
 	}
 

registry/handlers/helpers.go

@@ -6,7 +6,6 @@ import (
 	"net/http"
 
 	ctxu "github.com/docker/distribution/context"
-	"github.com/docker/distribution/registry/api/errcode"
 )
 
 // closeResources closes all the provided resources after running the target
@@ -23,7 +22,9 @@ func closeResources(handler http.Handler, closers ...io.Closer) http.Handler {
 // copyFullPayload copies the payload of an HTTP request to destWriter. If it
 // receives less content than expected, and the client disconnected during the
 // upload, it avoids sending a 400 error to keep the logs cleaner.
-func copyFullPayload(responseWriter http.ResponseWriter, r *http.Request, destWriter io.Writer, context ctxu.Context, action string, errSlice *errcode.Errors) error {
+//
+// The copy will be limited to `limit` bytes, if limit is greater than zero.
+func copyFullPayload(responseWriter http.ResponseWriter, r *http.Request, destWriter io.Writer, limit int64, context ctxu.Context, action string) error {
 	// Get a channel that tells us if the client disconnects
 	var clientClosed <-chan bool
 	if notifier, ok := responseWriter.(http.CloseNotifier); ok {
@@ -32,8 +33,13 @@ func copyFullPayload(responseWriter http.ResponseWriter, r *http.Request, destWr
 		ctxu.GetLogger(context).Warnf("the ResponseWriter does not implement CloseNotifier (type: %T)", responseWriter)
 	}
 
+	var body = r.Body
+	if limit > 0 {
+		body = http.MaxBytesReader(responseWriter, body, limit)
+	}
+
 	// Read in the data, if any.
-	copied, err := io.Copy(destWriter, r.Body)
+	copied, err := io.Copy(destWriter, body)
 	if clientClosed != nil && (err != nil || (r.ContentLength > 0 && copied < r.ContentLength)) {
 		// Didn't receive as much content as expected. Did the client
 		// disconnect during the request? If so, avoid returning a 400
@@ -58,7 +64,6 @@ func copyFullPayload(responseWriter http.ResponseWriter, r *http.Request, destWr
 
 	if err != nil {
 		ctxu.GetLogger(context).Errorf("unknown error reading request payload: %v", err)
-		*errSlice = append(*errSlice, errcode.ErrorCodeUnknown.WithDetail(err))
 		return err
 	}
 

registry/handlers/images.go

@@ -22,8 +22,9 @@ import (
 // These constants determine which architecture and OS to choose from a
 // manifest list when downconverting it to a schema1 manifest.
 const (
-	defaultArch = "amd64"
+	defaultArch         = "amd64"
-	defaultOS   = "linux"
+	defaultOS           = "linux"
+	maxManifestBodySize = 4 << 20
 )
 
 // imageManifestDispatcher takes the request context and builds the
@@ -241,8 +242,9 @@ func (imh *imageManifestHandler) PutImageManifest(w http.ResponseWriter, r *http
 	}
 
 	var jsonBuf bytes.Buffer
-	if err := copyFullPayload(w, r, &jsonBuf, imh, "image manifest PUT", &imh.Errors); err != nil {
+	if err := copyFullPayload(w, r, &jsonBuf, maxManifestBodySize, imh, "image manifest PUT"); err != nil {
 		// copyFullPayload reports the error if necessary
+		imh.Errors = append(imh.Errors, v2.ErrorCodeManifestInvalid.WithDetail(err.Error()))
 		return
 	}
 

registry/storage/blobstore.go

@@ -27,7 +27,7 @@ func (bs *blobStore) Get(ctx context.Context, dgst digest.Digest) ([]byte, error
 		return nil, err
 	}
 
-	p, err := bs.driver.GetContent(ctx, bp)
+	p, err := getContent(ctx, bs.driver, bp)
 	if err != nil {
 		switch err.(type) {
 		case driver.PathNotFoundError:
@@ -37,7 +37,7 @@ func (bs *blobStore) Get(ctx context.Context, dgst digest.Digest) ([]byte, error
 		return nil, err
 	}
 
-	return p, err
+	return p, nil
 }
 
 func (bs *blobStore) Open(ctx context.Context, dgst digest.Digest) (distribution.ReadSeekCloser, error) {

registry/storage/io.go

@@ -0,0 +1,71 @@
+package storage
+
+import (
+	"errors"
+	"io"
+	"io/ioutil"
+
+	"github.com/docker/distribution/context"
+	"github.com/docker/distribution/registry/storage/driver"
+)
+
+const (
+	maxBlobGetSize = 4 << 20
+)
+
+func getContent(ctx context.Context, driver driver.StorageDriver, p string) ([]byte, error) {
+	r, err := driver.Reader(ctx, p, 0)
+	if err != nil {
+		return nil, err
+	}
+
+	return readAllLimited(r, maxBlobGetSize)
+}
+
+func readAllLimited(r io.Reader, limit int64) ([]byte, error) {
+	r = limitReader(r, limit)
+	return ioutil.ReadAll(r)
+}
+
+// limitReader returns a new reader limited to n bytes. Unlike io.LimitReader,
+// this returns an error when the limit reached.
+func limitReader(r io.Reader, n int64) io.Reader {
+	return &limitedReader{r: r, n: n}
+}
+
+// limitedReader implements a reader that errors when the limit is reached.
+//
+// Partially cribbed from net/http.MaxBytesReader.
+type limitedReader struct {
+	r   io.Reader // underlying reader
+	n   int64     // max bytes remaining
+	err error     // sticky error
+}
+
+func (l *limitedReader) Read(p []byte) (n int, err error) {
+	if l.err != nil {
+		return 0, l.err
+	}
+	if len(p) == 0 {
+		return 0, nil
+	}
+	// If they asked for a 32KB byte read but only 5 bytes are
+	// remaining, no need to read 32KB. 6 bytes will answer the
+	// question of the whether we hit the limit or go past it.
+	if int64(len(p)) > l.n+1 {
+		p = p[:l.n+1]
+	}
+	n, err = l.r.Read(p)
+
+	if int64(n) <= l.n {
+		l.n -= int64(n)
+		l.err = err
+		return n, err
+	}
+
+	n = int(l.n)
+	l.n = 0
+
+	l.err = errors.New("storage: read exceeds limit")
+	return n, l.err
+}