Enable plugin-based validation of user's ref related operations

After user is authorized to perform a given ref operation, but just
before it is performed, invoke validation from plugins.

Validation is invoked for ref create, delete and update (including
non-ff) operations caused by user through either push or call to
existing ref related Gerrit endpoints (create/delete branch/es).

Change-Id: I11cbe51f54e7d133b336ab503577653b6fe0f443
Signed-off-by: Jacek Centkowski <geminica.programs@gmail.com>

Documentation/config-validation.txt

@@ -21,16 +21,18 @@ and cherry-pick buttons.
 Out of the box, Gerrit includes a plugin that checks the length of the
 subject and body lines of commit messages on uploaded commits.
 
-[[ref-operation-validation]]
-== Ref operation validation
+[[user-ref-operations-validation]]
+== User ref operations validation
 
 
 Plugins implementing the `RefOperationValidationListener` interface can
-perform additional validation checks against ref creation/deletion operation
-before it is applied to the git repository.
+perform additional validation checks against user ref operations (resulting
+from either push or corresponding Gerrit REST/SSH endpoints call e.g.
+create branch etc.). Namely including ref creation, deletion and update
+(also non-fast-forward) before they are applied to the git repository.
 
-If the ref operation fails the validation, the plugin can throw an exception
-which will cause the operation to fail.
+The plugin can throw an exception which will cause the operation to fail,
+and prevent the ref update from being applied.
 
 [[pre-merge-validation]]
 == Pre-merge validation

gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java

@@ -100,6 +100,9 @@ import com.google.gerrit.server.git.MultiProgressMonitor.Task;
 import com.google.gerrit.server.git.validators.CommitValidationException;
 import com.google.gerrit.server.git.validators.CommitValidationMessage;
 import com.google.gerrit.server.git.validators.CommitValidators;
+import com.google.gerrit.server.git.validators.RefOperationValidationException;
+import com.google.gerrit.server.git.validators.RefOperationValidators;
+import com.google.gerrit.server.git.validators.ValidationMessage;
 import com.google.gerrit.server.mail.MailUtil.MailRecipients;
 import com.google.gerrit.server.notedb.ChangeNotes;
 import com.google.gerrit.server.notedb.NotesMigration;
@@ -289,6 +292,7 @@ public class ReceiveCommits {
   private final ProjectCache projectCache;
   private final String canonicalWebUrl;
   private final CommitValidators.Factory commitValidatorsFactory;
+  private final RefOperationValidators.Factory refValidatorsFactory;
   private final TagCache tagCache;
   private final AccountCache accountCache;
   private final ChangeInserter.Factory changeInserterFactory;
@@ -329,7 +333,7 @@ public class ReceiveCommits {
   private final NotesMigration notesMigration;
   private final ChangeEditUtil editUtil;
 
-  private final List<CommitValidationMessage> messages = new ArrayList<>();
+  private final List<ValidationMessage> messages = new ArrayList<>();
   private ListMultimap<Error, String> errors = LinkedListMultimap.create();
   private Task newProgress;
   private Task replaceProgress;
@@ -355,6 +359,7 @@ public class ReceiveCommits {
       @Nullable SearchingChangeCacheImpl changeCache,
       ChangeInserter.Factory changeInserterFactory,
       CommitValidators.Factory commitValidatorsFactory,
+      RefOperationValidators.Factory refValidatorsFactory,
       @CanonicalWebUrl String canonicalWebUrl,
       RequestScopePropagator requestScopePropagator,
       SshInfo sshInfo,
@@ -392,6 +397,7 @@ public class ReceiveCommits {
     this.accountCache = accountCache;
     this.changeInserterFactory = changeInserterFactory;
     this.commitValidatorsFactory = commitValidatorsFactory;
+    this.refValidatorsFactory = refValidatorsFactory;
     this.requestScopePropagator = requestScopePropagator;
     this.sshInfo = sshInfo;
     this.allProjectsName = allProjectsName;
@@ -544,7 +550,7 @@ public class ReceiveCommits {
   }
 
   void sendMessages() {
-    for (CommitValidationMessage m : messages) {
+    for (ValidationMessage m : messages) {
       if (m.isError()) {
         messageSender.sendError(m.getMessage());
       } else {
@@ -1096,6 +1102,9 @@ public class ReceiveCommits {
 
     RefControl ctl = projectControl.controlForRef(cmd.getRefName());
     if (ctl.canCreate(db, rp.getRepository(), obj)) {
+      if (!validRefOperation(cmd)) {
+        return;
+      }
       validateNewCommits(ctl, cmd);
       batch.addCommand(cmd);
     } else {
@@ -1111,6 +1120,9 @@ public class ReceiveCommits {
         return;
       }
 
+      if (!validRefOperation(cmd)) {
+        return;
+      }
       validateNewCommits(ctl, cmd);
       batch.addCommand(cmd);
     } else {
@@ -1148,6 +1160,9 @@ public class ReceiveCommits {
       errors.put(Error.DELETE_CHANGES, ctl.getRefName());
       reject(cmd, "cannot delete changes");
     } else if (ctl.canDelete()) {
+      if (!validRefOperation(cmd)) {
+        return;
+      }
       batch.addCommand(cmd);
     } else {
       if (RefNames.REFS_CONFIG.equals(ctl.getRefName())) {
@@ -1182,6 +1197,9 @@ public class ReceiveCommits {
     }
 
     if (ctl.canForceUpdate()) {
+      if (!validRefOperation(cmd)) {
+        return;
+      }
       batch.setAllowNonFastForwards(true).addCommand(cmd);
     } else {
       cmd.setResult(REJECTED_NONFASTFORWARD, " need '"
@@ -2399,6 +2417,21 @@ public class ReceiveCommits {
     }
   }
 
+  private boolean validRefOperation(ReceiveCommand cmd) {
+    RefOperationValidators refValidators =
+        refValidatorsFactory.create(getProject(), user, cmd);
+
+    try {
+      messages.addAll(refValidators.validateForRefOperation());
+    } catch (RefOperationValidationException e) {
+      messages.addAll(Lists.newArrayList(e.getMessages()));
+      reject(cmd, e.getMessage());
+      return false;
+    }
+
+    return true;
+  }
+
   private void validateNewCommits(RefControl ctl, ReceiveCommand cmd) {
     if (ctl.canForgeAuthor()
         && ctl.canForgeCommitter()

gerrit-server/src/main/java/com/google/gerrit/server/project/CreateBranch.java

@@ -55,6 +55,7 @@ public class CreateBranch implements RestModifyView<ProjectResource, BranchInput
   private final GitRepositoryManager repoManager;
   private final Provider<ReviewDb> db;
   private final GitReferenceUpdated referenceUpdated;
+  private final RefValidationHelper refCreationValidator;
   private String ref;
 
   @Inject
@@ -62,11 +63,14 @@ public class CreateBranch implements RestModifyView<ProjectResource, BranchInput
       GitRepositoryManager repoManager,
       Provider<ReviewDb> db,
       GitReferenceUpdated referenceUpdated,
+      RefValidationHelper.Factory refHelperFactory,
       @Assisted String ref) {
     this.identifiedUser = identifiedUser;
     this.repoManager = repoManager;
     this.db = db;
     this.referenceUpdated = referenceUpdated;
+    this.refCreationValidator =
+        refHelperFactory.create(ReceiveCommand.Type.CREATE);
     this.ref = ref;
   }
 
@@ -123,6 +127,8 @@ public class CreateBranch implements RestModifyView<ProjectResource, BranchInput
         u.setNewObjectId(object.copy());
         u.setRefLogIdent(identifiedUser.get().newRefLogIdent());
         u.setRefLogMessage("created via REST from " + input.revision, false);
+        refCreationValidator.validateRefOperation(
+            rsrc.getName(), identifiedUser.get(), u);
         final RefUpdate.Result result = u.update(rw);
         switch (result) {
           case FAST_FORWARD:

gerrit-server/src/main/java/com/google/gerrit/server/project/DeleteBranch.java

@@ -50,16 +50,20 @@ public class DeleteBranch implements RestModifyView<BranchResource, Input> {
   private final GitRepositoryManager repoManager;
   private final Provider<InternalChangeQuery> queryProvider;
   private final GitReferenceUpdated referenceUpdated;
+  private final RefValidationHelper refDeletionValidator;
 
   @Inject
   DeleteBranch(Provider<IdentifiedUser> identifiedUser,
       GitRepositoryManager repoManager,
       Provider<InternalChangeQuery> queryProvider,
-      GitReferenceUpdated referenceUpdated) {
+      GitReferenceUpdated referenceUpdated,
+      RefValidationHelper.Factory refHelperFactory) {
     this.identifiedUser = identifiedUser;
     this.repoManager = repoManager;
     this.queryProvider = queryProvider;
     this.referenceUpdated = referenceUpdated;
+    this.refDeletionValidator =
+        refHelperFactory.create(ReceiveCommand.Type.DELETE);
   }
 
   @Override
@@ -78,6 +82,8 @@ public class DeleteBranch implements RestModifyView<BranchResource, Input> {
       RefUpdate.Result result;
       RefUpdate u = r.updateRef(rsrc.getRef());
       u.setForceUpdate(true);
+      refDeletionValidator.validateRefOperation(
+          rsrc.getName(), identifiedUser.get(), u);
       int remainingLockFailureCalls = MAX_LOCK_FAILURE_CALLS;
       for (;;) {
         try {

gerrit-server/src/main/java/com/google/gerrit/server/project/DeleteBranches.java

@@ -35,6 +35,7 @@ import org.eclipse.jgit.lib.BatchRefUpdate;
 import org.eclipse.jgit.lib.NullProgressMonitor;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.RefUpdate;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevWalk;
 import org.eclipse.jgit.transport.ReceiveCommand;
@@ -53,16 +54,20 @@ public class DeleteBranches
   private final GitRepositoryManager repoManager;
   private final Provider<InternalChangeQuery> queryProvider;
   private final GitReferenceUpdated referenceUpdated;
+  private final RefValidationHelper refDeletionValidator;
 
   @Inject
   DeleteBranches(Provider<IdentifiedUser> identifiedUser,
       GitRepositoryManager repoManager,
       Provider<InternalChangeQuery> queryProvider,
-      GitReferenceUpdated referenceUpdated) {
+      GitReferenceUpdated referenceUpdated,
+      RefValidationHelper.Factory refHelperFactory) {
     this.identifiedUser = identifiedUser;
     this.repoManager = repoManager;
     this.queryProvider = queryProvider;
     this.referenceUpdated = referenceUpdated;
+    this.refDeletionValidator =
+        refHelperFactory.create(ReceiveCommand.Type.DELETE);
   }
 
   @Override
@@ -100,7 +105,8 @@ public class DeleteBranches
   }
 
   private ReceiveCommand createDeleteCommand(ProjectResource project,
-      Repository r, String branch) throws OrmException, IOException {
+      Repository r, String branch)
+          throws OrmException, IOException, ResourceConflictException {
     Ref ref = r.getRefDatabase().getRef(branch);
     ReceiveCommand command;
     if (ref == null) {
@@ -120,6 +126,10 @@ public class DeleteBranches
     if (!queryProvider.get().setLimit(1).byBranchOpen(branchKey).isEmpty()) {
       command.setResult(Result.REJECTED_OTHER_REASON, "it has open changes");
     }
+    RefUpdate u = r.updateRef(branch);
+    u.setForceUpdate(true);
+    refDeletionValidator.validateRefOperation(
+        project.getName(), identifiedUser.get(), u);
     return command;
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/project/Module.java

@@ -69,6 +69,7 @@ public class Module extends RestApiModule {
     post(PROJECT_KIND, "branches:delete").to(DeleteBranches.class);
     factory(CreateBranch.Factory.class);
     get(BRANCH_KIND, "mergeable").to(CheckMergeability.class);
+    factory(RefValidationHelper.Factory.class);
     get(BRANCH_KIND, "reflog").to(GetReflog.class);
     child(BRANCH_KIND, "files").to(FilesCollection.class);
     get(FILE_KIND, "content").to(GetContent.class);

gerrit-server/src/main/java/com/google/gerrit/server/project/RefValidationHelper.java

@@ -0,0 +1,56 @@
+// Copyright (C) 2014 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.project;
+
+import com.google.gerrit.extensions.restapi.ResourceConflictException;
+import com.google.gerrit.reviewdb.client.Project;
+import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.git.validators.RefOperationValidators;
+import com.google.gerrit.server.validators.ValidationException;
+import com.google.inject.Inject;
+import com.google.inject.assistedinject.Assisted;
+
+import org.eclipse.jgit.lib.RefUpdate;
+import org.eclipse.jgit.transport.ReceiveCommand.Type;
+
+public class RefValidationHelper {
+  public interface Factory {
+    RefValidationHelper create(Type operationType);
+  }
+
+  private final RefOperationValidators.Factory refValidatorsFactory;
+  private final Type operationType;
+
+  @Inject
+  RefValidationHelper(RefOperationValidators.Factory refValidatorsFactory,
+      @Assisted Type operationType) {
+    this.refValidatorsFactory = refValidatorsFactory;
+    this.operationType = operationType;
+  }
+
+  public void validateRefOperation(String projectName, IdentifiedUser user,
+      RefUpdate update) throws ResourceConflictException {
+    RefOperationValidators refValidators =
+        refValidatorsFactory.create(
+            new Project(new Project.NameKey(projectName)),
+            user,
+            RefOperationValidators.getCommand(update, operationType));
+    try {
+      refValidators.validateForRefOperation();
+    } catch (ValidationException e) {
+      throw new ResourceConflictException(e.getMessage());
+    }
+  }
+}