detect and remove invalid streams and sd blobs

CHANGELOG.md

@@ -26,7 +26,7 @@ at anytime.
   * `get` failing with a non-useful error message when given a uri for a channel claim
   * exception checking in several wallet unit tests
   * daemon not erring properly for non-numeric values being passed to the `bid` parameter for the `publish` method
-  * incorrect `blob_num` for the stream terminator blob, which would result in creating invalid streams (https://github.com/lbryio/lbry/issues/1124)
+  * incorrect `blob_num` for the stream terminator blob, which would result in creating invalid streams. Such invalid streams are detected on startup and are automatically removed (https://github.com/lbryio/lbry/issues/1124)
 
 ### Deprecated
   * `channel_list_mine`, replaced with `channel_list`

lbrynet/core/StreamDescriptor.py

@@ -357,12 +357,6 @@ def get_stream_hash(hex_stream_name, key, hex_suggested_file_name, blob_infos):
     h.update(key)
     h.update(hex_suggested_file_name)
     blobs_hashsum = get_lbry_hash_obj()
-    if any(blob['length'] for blob in blob_infos if blob['length'] <= 0):
-        raise InvalidStreamDescriptorError("Contains invalid length data blobs")
-    if blob_infos[-1]['length'] != 0:
-        raise InvalidStreamDescriptorError("Does not end with a zero-length blob.")
-    if 'blob_hash' in blob_infos[-1]:
-        raise InvalidStreamDescriptorError("Stream terminator blob should not have a hash")
     for blob in blob_infos:
         blobs_hashsum.update(get_blob_hashsum(blob))
     h.update(blobs_hashsum.digest())
@@ -384,6 +378,12 @@ def validate_descriptor(stream_info):
         blobs = stream_info['blobs']
     except KeyError as e:
         raise InvalidStreamDescriptorError("Missing '%s'" % (e.args[0]))
+    if stream_info['blobs'][-1]['length'] != 0:
+        raise InvalidStreamDescriptorError("Does not end with a zero-length blob.")
+    if any([False if blob_info['length'] > 0 else True for blob_info in stream_info['blobs'][:-1]]):
+        raise InvalidStreamDescriptorError("Contains zero-length data blob")
+    if 'blob_hash' in stream_info['blobs'][-1]:
+        raise InvalidStreamDescriptorError("Stream terminator blob should not have a hash")
 
     verify_hex(key, "key")
     verify_hex(hex_suggested_file_name, "suggested file name")
@@ -448,6 +448,11 @@ def download_sd_blob(session, blob_hash, payment_rate_manager, timeout=None):
     sd_blob = yield downloader.download()
     sd_reader = BlobStreamDescriptorReader(sd_blob)
     sd_info = yield sd_reader.get_info()
+    try:
+        validate_descriptor(sd_info)
+    except InvalidStreamDescriptorError as err:
+        yield session.blob_manager.delete_blobs([blob_hash])
+        raise err
     raw_sd = yield sd_reader._get_raw_data()
     yield session.blob_manager.storage.add_known_blob(blob_hash, len(raw_sd))
     yield save_sd_info(session.blob_manager, sd_blob.blob_hash, sd_info)

lbrynet/daemon/Daemon.py

@@ -50,6 +50,7 @@ from lbrynet.core.Error import NoSuchStreamHash, DownloadDataTimeout, DownloadSD
 from lbrynet.core.Error import NullFundsError, NegativeFundsError
 from lbrynet.core.Peer import Peer
 from lbrynet.core.SinglePeerDownloader import SinglePeerDownloader
+from lbrynet.core.client.StandaloneBlobDownloader import StandaloneBlobDownloader
 
 log = logging.getLogger(__name__)
 
@@ -621,7 +622,11 @@ class Daemon(AuthJSONRPCServer):
 
         rate_manager = rate_manager or self.session.payment_rate_manager
         timeout = timeout or 30
-        return download_sd_blob(self.session, blob_hash, rate_manager, timeout)
+        downloader = StandaloneBlobDownloader(
+            blob_hash, self.session.blob_manager, self.session.peer_finder, self.session.rate_limiter,
+            rate_manager, self.session.wallet, timeout
+        )
+        return downloader.download()
 
     @defer.inlineCallbacks
     def _get_stream_analytics_report(self, claim_dict):

lbrynet/daemon/Downloader.py

@@ -5,7 +5,7 @@ from twisted.internet.task import LoopingCall
 
 from lbryschema.fee import Fee
 
-from lbrynet.core.Error import InsufficientFundsError, KeyFeeAboveMaxAllowed
+from lbrynet.core.Error import InsufficientFundsError, KeyFeeAboveMaxAllowed, InvalidStreamDescriptorError
 from lbrynet.core.Error import DownloadDataTimeout, DownloadCanceledError, DownloadSDTimeout
 from lbrynet.core.utils import safe_start_looping_call, safe_stop_looping_call
 from lbrynet.core.StreamDescriptor import download_sd_blob
@@ -204,14 +204,12 @@ class GetStream(object):
 
         safe_start_looping_call(self.checker, 1)
         self.set_status(DOWNLOAD_METADATA_CODE, name)
+        try:
             sd_blob = yield self._download_sd_blob()
-
             yield self._download(sd_blob, name, key_fee, txid, nout, file_name)
             self.set_status(DOWNLOAD_RUNNING_CODE, name)
-
-        try:
             yield self.data_downloading_deferred
-        except DownloadDataTimeout as err:
+        except (DownloadDataTimeout, InvalidStreamDescriptorError) as err:
             safe_stop_looping_call(self.checker)
             raise err
 

lbrynet/file_manager/EncryptedFileCreator.py

@@ -10,7 +10,7 @@ from twisted.internet import defer
 from twisted.protocols.basic import FileSender
 
 from lbrynet.core.StreamDescriptor import BlobStreamDescriptorWriter, EncryptedFileStreamType
-from lbrynet.core.StreamDescriptor import format_sd_info, get_stream_hash
+from lbrynet.core.StreamDescriptor import format_sd_info, get_stream_hash, validate_descriptor
 from lbrynet.cryptstream.CryptStreamCreator import CryptStreamCreator
 
 log = logging.getLogger(__name__)
@@ -40,11 +40,15 @@ class EncryptedFileStreamCreator(CryptStreamCreator):
             hexlify(self.name), hexlify(self.key), hexlify(self.name),
             self.blob_infos
         )
+
         # generate the sd info
         self.sd_info = format_sd_info(
             EncryptedFileStreamType, hexlify(self.name), hexlify(self.key),
             hexlify(self.name), self.stream_hash, self.blob_infos
         )
+
+        # sanity check
+        validate_descriptor(self.sd_info)
         return defer.succeed(self.stream_hash)
 
 

lbrynet/file_manager/EncryptedFileManager.py

@@ -6,12 +6,12 @@ import logging
 
 from twisted.internet import defer, task, reactor
 from twisted.python.failure import Failure
-
+from lbrynet.core.Error import InvalidStreamDescriptorError
 from lbrynet.reflector.reupload import reflect_stream
 from lbrynet.core.PaymentRateManager import NegotiatedPaymentRateManager
 from lbrynet.file_manager.EncryptedFileDownloader import ManagedEncryptedFileDownloader
 from lbrynet.file_manager.EncryptedFileDownloader import ManagedEncryptedFileDownloaderFactory
-from lbrynet.core.StreamDescriptor import EncryptedFileStreamType, get_sd_info
+from lbrynet.core.StreamDescriptor import EncryptedFileStreamType, get_sd_info, validate_descriptor
 from lbrynet.cryptstream.client.CryptStreamDownloader import AlreadyStoppedError
 from lbrynet.cryptstream.client.CryptStreamDownloader import CurrentlyStoppingError
 from lbrynet.core.utils import safe_start_looping_call, safe_stop_looping_call
@@ -113,13 +113,23 @@ class EncryptedFileManager(object):
                 file_info['suggested_file_name']
             )
             yield lbry_file.get_claim_info()
+            try:
+                # verify the stream is valid (we might have downloaded an invalid stream
+                # in the past when the validation check didn't work)
+                stream_info = yield get_sd_info(self.storage, file_info['stream_hash'], include_blobs=True)
+                validate_descriptor(stream_info)
+            except InvalidStreamDescriptorError as err:
+                log.warning("Stream for descriptor %s is invalid (%s), cleaning it up",
+                            lbry_file.sd_hash, err.message)
+                yield lbry_file.delete_data()
+                yield self.session.storage.delete_stream(lbry_file.stream_hash)
+            else:
                 try:
                     # restore will raise an Exception if status is unknown
                     lbry_file.restore(file_info['status'])
                     self.lbry_files.append(lbry_file)
                 except Exception:
-                log.warning("Failed to start %i", file_info['rowid'])
+                    log.warning("Failed to start %i", file_info.get('rowid'))
-                continue
         log.info("Started %i lbry files", len(self.lbry_files))
         if self.auto_re_reflect is True:
             safe_start_looping_call(self.lbry_file_reflector, self.auto_re_reflect_interval)