sync/internal_api/write_node.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "sync/internal_api/public/write_node.h"
   6
   7 #include "base/strings/string_util.h"
   8 #include "base/strings/utf_string_conversions.h"
   9 #include "base/values.h"
  10 #include "sync/internal_api/public/base_transaction.h"
  11 #include "sync/internal_api/public/write_transaction.h"
  12 #include "sync/internal_api/syncapi_internal.h"
  13 #include "sync/protocol/bookmark_specifics.pb.h"
  14 #include "sync/protocol/typed_url_specifics.pb.h"
  15 #include "sync/syncable/mutable_entry.h"
  16 #include "sync/syncable/nigori_util.h"
  17 #include "sync/syncable/syncable_util.h"
  18 #include "sync/util/cryptographer.h"
  19
  20 using std::string;
  21 using std::vector;
  22
  23 namespace syncer {
  24
  25 using syncable::kEncryptedString;
  26 using syncable::SPECIFICS;
  27
  28 static const char kDefaultNameForNewNodes[] = " ";
  29
  30 void WriteNode::SetIsFolder(bool folder) {
  31   if (entry_->GetIsDir() == folder)
  32     return;  // Skip redundant changes.
  33
  34   entry_->PutIsDir(folder);
  35   MarkForSyncing();
  36 }
  37
  38 void WriteNode::SetTitle(const std::string& title) {
  39   DCHECK_NE(GetModelType(), UNSPECIFIED);
  40   ModelType type = GetModelType();
  41   // It's possible the nigori lost the set of encrypted types. If the current
  42   // specifics are already encrypted, we want to ensure we continue encrypting.
  43   bool needs_encryption = GetTransaction()->GetEncryptedTypes().Has(type) ||
  44                           entry_->GetSpecifics().has_encrypted();
  45
  46   // If this datatype is encrypted and is not a bookmark, we disregard the
  47   // specified title in favor of kEncryptedString. For encrypted bookmarks the
  48   // NON_UNIQUE_NAME will still be kEncryptedString, but we store the real title
  49   // into the specifics. All strings compared are server legal strings.
  50   std::string new_legal_title;
  51   if (type != BOOKMARKS && needs_encryption) {
  52     new_legal_title = kEncryptedString;
  53   } else {
  54     DCHECK(base::IsStringUTF8(title));
  55     SyncAPINameToServerName(title, &new_legal_title);
  56     base::TruncateUTF8ToByteSize(new_legal_title, 255, &new_legal_title);
  57   }
  58
  59   std::string current_legal_title;
  60   if (BOOKMARKS == type &&
  61       entry_->GetSpecifics().has_encrypted()) {
  62     // Encrypted bookmarks only have their title in the unencrypted specifics.
  63     current_legal_title = GetBookmarkSpecifics().title();
  64   } else {
  65     // Non-bookmarks and legacy bookmarks (those with no title in their
  66     // specifics) store their title in NON_UNIQUE_NAME. Non-legacy bookmarks
  67     // store their title in specifics as well as NON_UNIQUE_NAME.
  68     current_legal_title = entry_->GetNonUniqueName();
  69   }
  70
  71   bool title_matches = (current_legal_title == new_legal_title);
  72   bool encrypted_without_overwriting_name = (needs_encryption &&
  73       entry_->GetNonUniqueName() != kEncryptedString);
  74
  75   // For bookmarks, we also set the title field in the specifics.
  76   // TODO(zea): refactor bookmarks to not need this functionality.
  77   sync_pb::EntitySpecifics specifics = GetEntitySpecifics();
  78   if (GetModelType() == BOOKMARKS &&
  79       specifics.bookmark().title() != new_legal_title) {
  80     specifics.mutable_bookmark()->set_title(new_legal_title);
  81     SetEntitySpecifics(specifics);  // Does it's own encryption checking.
  82     title_matches = false;
  83   }
  84
  85   // If the title matches and the NON_UNIQUE_NAME is properly overwritten as
  86   // necessary, nothing needs to change.
  87   if (title_matches && !encrypted_without_overwriting_name) {
  88     DVLOG(2) << "Title matches, dropping change.";
  89     return;
  90   }
  91
  92   // For bookmarks, this has to happen after we set the title in the specifics,
  93   // because the presence of a title in the NON_UNIQUE_NAME is what controls
  94   // the logic deciding whether this is an empty node or a legacy bookmark.
  95   // See BaseNode::GetUnencryptedSpecific(..).
  96   if (needs_encryption)
  97     entry_->PutNonUniqueName(kEncryptedString);
  98   else
  99     entry_->PutNonUniqueName(new_legal_title);
 100
 101   DVLOG(1) << "Overwriting title of type "
 102            << ModelTypeToString(type)
 103            << " and marking for syncing.";
 104   MarkForSyncing();
 105 }
 106
 107 void WriteNode::SetBookmarkSpecifics(
 108     const sync_pb::BookmarkSpecifics& new_value) {
 109   sync_pb::EntitySpecifics entity_specifics;
 110   entity_specifics.mutable_bookmark()->CopyFrom(new_value);
 111   SetEntitySpecifics(entity_specifics);
 112 }
 113
 114 void WriteNode::SetNigoriSpecifics(
 115     const sync_pb::NigoriSpecifics& new_value) {
 116   sync_pb::EntitySpecifics entity_specifics;
 117   entity_specifics.mutable_nigori()->CopyFrom(new_value);
 118   SetEntitySpecifics(entity_specifics);
 119 }
 120
 121 void WriteNode::SetPasswordSpecifics(
 122     const sync_pb::PasswordSpecificsData& data) {
 123   DCHECK_EQ(GetModelType(), PASSWORDS);
 124
 125   Cryptographer* cryptographer = GetTransaction()->GetCryptographer();
 126
 127   // We have to do the idempotency check here (vs in UpdateEntryWithEncryption)
 128   // because Passwords have their encrypted data within the PasswordSpecifics,
 129   // vs within the EntitySpecifics like all the other types.
 130   const sync_pb::EntitySpecifics& old_specifics = GetEntry()->GetSpecifics();
 131   sync_pb::EntitySpecifics entity_specifics;
 132   // Copy over the old specifics if they exist.
 133   if (GetModelTypeFromSpecifics(old_specifics) == PASSWORDS) {
 134     entity_specifics.CopyFrom(old_specifics);
 135   } else {
 136     AddDefaultFieldValue(PASSWORDS, &entity_specifics);
 137   }
 138   sync_pb::PasswordSpecifics* password_specifics =
 139       entity_specifics.mutable_password();
 140   // This will only update password_specifics if the underlying unencrypted blob
 141   // was different from |data| or was not encrypted with the proper passphrase.
 142   if (!cryptographer->Encrypt(data, password_specifics->mutable_encrypted())) {
 143     LOG(ERROR) << "Failed to encrypt password, possibly due to sync node "
 144                << "corruption";
 145     return;
 146   }
 147   SetEntitySpecifics(entity_specifics);
 148 }
 149
 150 void WriteNode::SetEntitySpecifics(
 151     const sync_pb::EntitySpecifics& new_value) {
 152   ModelType new_specifics_type =
 153       GetModelTypeFromSpecifics(new_value);
 154   CHECK(!new_value.password().has_client_only_encrypted_data());
 155   DCHECK_NE(new_specifics_type, UNSPECIFIED);
 156   DVLOG(1) << "Writing entity specifics of type "
 157            << ModelTypeToString(new_specifics_type);
 158   DCHECK_EQ(new_specifics_type, GetModelType());
 159
 160   // Preserve unknown fields.
 161   const sync_pb::EntitySpecifics& old_specifics = entry_->GetSpecifics();
 162   sync_pb::EntitySpecifics new_specifics;
 163   new_specifics.CopyFrom(new_value);
 164   new_specifics.mutable_unknown_fields()->MergeFrom(
 165       old_specifics.unknown_fields());
 166
 167   // Will update the entry if encryption was necessary.
 168   if (!UpdateEntryWithEncryption(GetTransaction()->GetWrappedTrans(),
 169                                  new_specifics,
 170                                  entry_)) {
 171     return;
 172   }
 173   if (entry_->GetSpecifics().has_encrypted()) {
 174     // EncryptIfNecessary already updated the entry for us and marked for
 175     // syncing if it was needed. Now we just make a copy of the unencrypted
 176     // specifics so that if this node is updated, we do not have to decrypt the
 177     // old data. Note that this only modifies the node's local data, not the
 178     // entry itself.
 179     SetUnencryptedSpecifics(new_value);
 180   }
 181
 182   DCHECK_EQ(new_specifics_type, GetModelType());
 183 }
 184
 185 void WriteNode::ResetFromSpecifics() {
 186   SetEntitySpecifics(GetEntitySpecifics());
 187 }
 188
 189 void WriteNode::SetTypedUrlSpecifics(
 190     const sync_pb::TypedUrlSpecifics& new_value) {
 191   sync_pb::EntitySpecifics entity_specifics;
 192   entity_specifics.mutable_typed_url()->CopyFrom(new_value);
 193   SetEntitySpecifics(entity_specifics);
 194 }
 195
 196 void WriteNode::SetExternalId(int64 id) {
 197   if (GetExternalId() != id)
 198     entry_->PutLocalExternalId(id);
 199 }
 200
 201 WriteNode::WriteNode(WriteTransaction* transaction)
 202     : entry_(NULL), transaction_(transaction) {
 203   DCHECK(transaction);
 204 }
 205
 206 WriteNode::~WriteNode() {
 207   delete entry_;
 208 }
 209
 210 // Find an existing node matching the ID |id|, and bind this WriteNode to it.
 211 // Return true on success.
 212 BaseNode::InitByLookupResult WriteNode::InitByIdLookup(int64 id) {
 213   DCHECK(!entry_) << "Init called twice";
 214   DCHECK_NE(id, kInvalidId);
 215   entry_ = new syncable::MutableEntry(transaction_->GetWrappedWriteTrans(),
 216                                       syncable::GET_BY_HANDLE, id);
 217   if (!entry_->good())
 218     return INIT_FAILED_ENTRY_NOT_GOOD;
 219   if (entry_->GetIsDel())
 220     return INIT_FAILED_ENTRY_IS_DEL;
 221   return DecryptIfNecessary() ? INIT_OK : INIT_FAILED_DECRYPT_IF_NECESSARY;
 222 }
 223
 224 // Find a node by client tag, and bind this WriteNode to it.
 225 // Return true if the write node was found, and was not deleted.
 226 // Undeleting a deleted node is possible by ClientTag.
 227 BaseNode::InitByLookupResult WriteNode::InitByClientTagLookup(
 228     ModelType model_type,
 229     const std::string& tag) {
 230   DCHECK(!entry_) << "Init called twice";
 231   if (tag.empty())
 232     return INIT_FAILED_PRECONDITION;
 233
 234   const std::string hash = syncable::GenerateSyncableHash(model_type, tag);
 235
 236   entry_ = new syncable::MutableEntry(transaction_->GetWrappedWriteTrans(),
 237                                       syncable::GET_BY_CLIENT_TAG, hash);
 238   if (!entry_->good())
 239     return INIT_FAILED_ENTRY_NOT_GOOD;
 240   if (entry_->GetIsDel())
 241     return INIT_FAILED_ENTRY_IS_DEL;
 242   return DecryptIfNecessary() ? INIT_OK : INIT_FAILED_DECRYPT_IF_NECESSARY;
 243 }
 244
 245 BaseNode::InitByLookupResult WriteNode::InitTypeRoot(ModelType type) {
 246   DCHECK(!entry_) << "Init called twice";
 247   if (!IsRealDataType(type))
 248     return INIT_FAILED_PRECONDITION;
 249   entry_ = new syncable::MutableEntry(transaction_->GetWrappedWriteTrans(),
 250                                       syncable::GET_TYPE_ROOT, type);
 251   if (!entry_->good())
 252     return INIT_FAILED_ENTRY_NOT_GOOD;
 253   if (entry_->GetIsDel())
 254     return INIT_FAILED_ENTRY_IS_DEL;
 255   ModelType model_type = GetModelType();
 256   DCHECK_EQ(model_type, NIGORI);
 257   return INIT_OK;
 258 }
 259
 260 // Create a new node with default properties, and bind this WriteNode to it.
 261 // Return true on success.
 262 bool WriteNode::InitBookmarkByCreation(const BaseNode& parent,
 263                                        const BaseNode* predecessor) {
 264   DCHECK(!entry_) << "Init called twice";
 265   // |predecessor| must be a child of |parent| or NULL.
 266   if (predecessor && predecessor->GetParentId() != parent.GetId()) {
 267     DCHECK(false);
 268     return false;
 269   }
 270
 271   syncable::Id parent_id = parent.GetEntry()->GetId();
 272   DCHECK(!parent_id.IsNull());
 273
 274   // Start out with a dummy name.  We expect
 275   // the caller to set a meaningful name after creation.
 276   string dummy(kDefaultNameForNewNodes);
 277
 278   entry_ = new syncable::MutableEntry(transaction_->GetWrappedWriteTrans(),
 279                                       syncable::CREATE, BOOKMARKS,
 280                                       parent_id, dummy);
 281
 282   if (!entry_->good())
 283     return false;
 284
 285   // Entries are untitled folders by default.
 286   entry_->PutIsDir(true);
 287
 288   if (!PutPredecessor(predecessor)) {
 289     return false;
 290   }
 291
 292   // Mark this entry as unsynced, to wake up the syncer.
 293   MarkForSyncing();
 294   return true;
 295 }
 296
 297 WriteNode::InitUniqueByCreationResult WriteNode::InitUniqueByCreation(
 298     ModelType model_type,
 299     const BaseNode& parent,
 300     const std::string& tag) {
 301   return InitUniqueByCreationImpl(model_type, parent.GetEntry()->GetId(), tag);
 302 }
 303
 304 WriteNode::InitUniqueByCreationResult WriteNode::InitUniqueByCreation(
 305     ModelType model_type,
 306     const std::string& tag) {
 307   return InitUniqueByCreationImpl(model_type, syncable::Id(), tag);
 308 }
 309
 310 // Create a new node with default properties and a client defined unique tag,
 311 // and bind this WriteNode to it.
 312 // Return true on success. If the tag exists in the database, then
 313 // we will attempt to undelete the node.
 314 WriteNode::InitUniqueByCreationResult WriteNode::InitUniqueByCreationImpl(
 315     ModelType model_type,
 316     const syncable::Id& parent_id,
 317     const std::string& tag) {
 318   // This DCHECK will only fail if init is called twice.
 319   DCHECK(!entry_);
 320   if (tag.empty()) {
 321     LOG(WARNING) << "InitUniqueByCreation failed due to empty tag.";
 322     return INIT_FAILED_EMPTY_TAG;
 323   }
 324
 325   const std::string hash = syncable::GenerateSyncableHash(model_type, tag);
 326
 327   // Start out with a dummy name.  We expect
 328   // the caller to set a meaningful name after creation.
 329   string dummy(kDefaultNameForNewNodes);
 330
 331   // Check if we have this locally and need to undelete it.
 332   scoped_ptr<syncable::MutableEntry> existing_entry(
 333       new syncable::MutableEntry(transaction_->GetWrappedWriteTrans(),
 334                                  syncable::GET_BY_CLIENT_TAG, hash));
 335
 336   if (existing_entry->good()) {
 337     if (existing_entry->GetIsDel()) {
 338       // Rules for undelete:
 339       // BASE_VERSION: Must keep the same.
 340       // ID: Essential to keep the same.
 341       // META_HANDLE: Must be the same, so we can't "split" the entry.
 342       // IS_DEL: Must be set to false, will cause reindexing.
 343       //         This one is weird because IS_DEL is true for "update only"
 344       //         items. It should be OK to undelete an update only.
 345       // MTIME/CTIME: Seems reasonable to just leave them alone.
 346       // IS_UNSYNCED: Must set this to true or face database insurrection.
 347       //              We do this below this block.
 348       // IS_UNAPPLIED_UPDATE: Either keep it the same or also set BASE_VERSION
 349       //                      to SERVER_VERSION. We keep it the same here.
 350       // IS_DIR: We'll leave it the same.
 351       // SPECIFICS: Reset it.
 352
 353       existing_entry->PutIsDel(false);
 354
 355       // Client tags are immutable and must be paired with the ID.
 356       // If a server update comes down with an ID and client tag combo,
 357       // and it already exists, always overwrite it and store only one copy.
 358       // We have to undelete entries because we can't disassociate IDs from
 359       // tags and updates.
 360
 361       existing_entry->PutNonUniqueName(dummy);
 362       existing_entry->PutParentId(parent_id);
 363
 364       // Put specifics to handle the case where this is not actually an
 365       // undeletion, but instead a collision with a newly downloaded,
 366       // processed, and unapplied server update.  This is a fix for
 367       // http://crbug.com/397766.
 368       sync_pb::EntitySpecifics specifics;
 369       AddDefaultFieldValue(model_type, &specifics);
 370       existing_entry->PutSpecifics(specifics);
 371     }  // Else just reuse the existing entry.
 372     entry_ = existing_entry.release();
 373   } else {
 374     entry_ = new syncable::MutableEntry(transaction_->GetWrappedWriteTrans(),
 375                                         syncable::CREATE,
 376                                         model_type, parent_id, dummy);
 377   }
 378
 379   if (!entry_->good())
 380     return INIT_FAILED_COULD_NOT_CREATE_ENTRY;
 381
 382   // Has no impact if the client tag is already set.
 383   entry_->PutUniqueClientTag(hash);
 384
 385   // We don't support directory and tag combinations.
 386   entry_->PutIsDir(false);
 387
 388   if (!parent_id.IsNull()) {
 389     if (!PutPredecessor(NULL))
 390       return INIT_FAILED_SET_PREDECESSOR;
 391   }
 392
 393   // Mark this entry as unsynced, to wake up the syncer.
 394   MarkForSyncing();
 395
 396   return INIT_SUCCESS;
 397 }
 398
 399 bool WriteNode::SetPosition(const BaseNode& new_parent,
 400                             const BaseNode* predecessor) {
 401   // |predecessor| must be a child of |new_parent| or NULL.
 402   if (predecessor && predecessor->GetParentId() != new_parent.GetId()) {
 403     DCHECK(false);
 404     return false;
 405   }
 406
 407   syncable::Id new_parent_id = new_parent.GetEntry()->GetId();
 408   DCHECK(!new_parent_id.IsNull());
 409
 410   // Filter out redundant changes if both the parent and the predecessor match.
 411   if (new_parent_id == entry_->GetParentId()) {
 412     const syncable::Id& old = entry_->GetPredecessorId();
 413     if ((!predecessor && old.IsNull()) ||
 414         (predecessor && (old == predecessor->GetEntry()->GetId()))) {
 415       return true;
 416     }
 417   }
 418
 419   entry_->PutParentId(new_parent_id);
 420
 421   if (!PutPredecessor(predecessor)) {
 422     return false;
 423   }
 424
 425   // Mark this entry as unsynced, to wake up the syncer.
 426   MarkForSyncing();
 427   return true;
 428 }
 429
 430 void WriteNode::SetAttachmentMetadata(
 431     const sync_pb::AttachmentMetadata& attachment_metadata) {
 432   entry_->PutAttachmentMetadata(attachment_metadata);
 433 }
 434
 435 const syncable::Entry* WriteNode::GetEntry() const {
 436   return entry_;
 437 }
 438
 439 const BaseTransaction* WriteNode::GetTransaction() const {
 440   return transaction_;
 441 }
 442
 443 syncable::MutableEntry* WriteNode::GetMutableEntryForTest() {
 444   return entry_;
 445 }
 446
 447 void WriteNode::Tombstone() {
 448   // These lines must be in this order.  The call to Put(IS_DEL) might choose to
 449   // unset the IS_UNSYNCED bit if the item was not known to the server at the
 450   // time of deletion.  It's important that the bit not be reset in that case.
 451   MarkForSyncing();
 452   entry_->PutIsDel(true);
 453 }
 454
 455 void WriteNode::Drop() {
 456   if (entry_->GetId().ServerKnows()) {
 457     entry_->PutIsDel(true);
 458   }
 459 }
 460
 461 bool WriteNode::PutPredecessor(const BaseNode* predecessor) {
 462   DCHECK(!entry_->GetParentId().IsNull());
 463   syncable::Id predecessor_id = predecessor ?
 464       predecessor->GetEntry()->GetId() : syncable::Id();
 465   return entry_->PutPredecessor(predecessor_id);
 466 }
 467
 468 void WriteNode::MarkForSyncing() {
 469   syncable::MarkForSyncing(entry_);
 470 }
 471
 472 }  // namespace syncer