SERVER-38275 ban explain with UUID

5 files changed, 70 insertions, 2 deletions

diff --git a/jstests/core/explain_uuid.js b/jstests/core/explain_uuid.js
new file mode 100644
index 00000000000..a7de30a1ef2
--- /dev/null
+++ b/jstests/core/explain_uuid.js
@@ -0,0 +1,56 @@
+/**
+ * Test that running explain() providing a collection UUID rather than collection name will fail
+ * cleanly.
+ */
+(function() {
+    "use strict";
+
+    // Use our own database so that we're guaranteed the only collection is this one.
+    const explainDB = db.getSiblingDB("explain_uuid_db");
+
+    assert.commandWorked(explainDB.dropDatabase());
+
+    const coll = explainDB.explain_uuid;
+    assert.writeOK(coll.insert({a: 1}));
+
+    const collInfos = explainDB.getCollectionInfos({name: coll.getName()});
+    assert.eq(collInfos.length, 1, collInfos);
+    const uuid = collInfos[0].info.uuid;
+
+    // Run a find explain looking up by UUID.
+    assert.commandFailedWithCode(explainDB.runCommand({explain: {find: uuid}}),
+                                 ErrorCodes.InvalidNamespace);
+
+    // Do similar for other commands.
+    assert.commandFailedWithCode(explainDB.runCommand({explain: {aggregate: uuid, cursor: {}}}),
+                                 ErrorCodes.TypeMismatch);
+
+    assert.commandFailedWithCode(explainDB.runCommand({explain: {count: uuid}}),
+                                 ErrorCodes.InvalidNamespace);
+
+    assert.commandFailedWithCode(explainDB.runCommand({explain: {distinct: uuid, key: "x"}}),
+                                 ErrorCodes.InvalidNamespace);
+
+    // When auth is enabled, running findAndModify with an invalid namespace will produce a special
+    // error during the auth check, rather than the generic 'InvalidNamespace' error.
+    const expectedCode = TestData.auth ? 17137 : ErrorCodes.InvalidNamespace;
+    assert.commandFailedWithCode(
+        explainDB.runCommand({explain: {findAndModify: uuid, query: {a: 1}, remove: true}}),
+        expectedCode);
+
+    assert.commandFailedWithCode(
+        explainDB.runCommand({explain: {delete: uuid, deletes: [{q: {}, limit: 1}]}}),
+        ErrorCodes.BadValue);
+
+    assert.commandFailedWithCode(explainDB.runCommand({
+        explain: {
+            update: uuid,
+            updates: [{
+                q: {a: 1},
+                u: {$set: {b: 1}},
+            }]
+        }
+    }),
+                                 ErrorCodes.BadValue);
+
+})();
diff --git a/src/mongo/db/commands.cpp b/src/mongo/db/commands.cpp
index 4ff86edc586..f7aa71e9184 100644
--- a/src/mongo/db/commands.cpp
+++ b/src/mongo/db/commands.cpp
@@ -126,6 +126,12 @@ NamespaceString Command::parseNsCollectionRequired(const string& dbname, const B
     // Accepts both BSON String and Symbol for collection name per SERVER-16260
     // TODO(kangas) remove Symbol support in MongoDB 3.0 after Ruby driver audit
     BSONElement first = cmdObj.firstElement();
+    const bool isUUID = (first.canonicalType() == canonicalizeBSONType(mongo::BinData) &&
+                         first.binDataType() == BinDataType::newUUID);
+    uassert(ErrorCodes::InvalidNamespace,
+            str::stream() << "Collection name must be provided. UUID is not valid in this "
+                          << "context",
+            !isUUID);
     uassert(ErrorCodes::InvalidNamespace,
             str::stream() << "collection name has invalid type " << typeName(first.type()),
             first.canonicalType() == canonicalizeBSONType(mongo::String));
diff --git a/src/mongo/db/commands/count_cmd.cpp b/src/mongo/db/commands/count_cmd.cpp
index f8af43deaf4..2a306facb7a 100644
--- a/src/mongo/db/commands/count_cmd.cpp
+++ b/src/mongo/db/commands/count_cmd.cpp
@@ -118,7 +118,7 @@ public:
                            BSONObjBuilder* out) const {
         const bool isExplain = true;
         Lock::DBLock dbLock(opCtx, dbname, MODE_IS);
-        auto nss = parseNsOrUUID(opCtx, dbname, cmdObj);
+        auto nss = parseNsCollectionRequired(dbname, cmdObj);
         auto request = CountRequest::parseFromBSON(nss, cmdObj, isExplain);
         if (!request.isOK()) {
             return request.getStatus();
diff --git a/src/mongo/db/commands/find_cmd.cpp b/src/mongo/db/commands/find_cmd.cpp
index c50f5a93e80..c913dde609e 100644
--- a/src/mongo/db/commands/find_cmd.cpp
+++ b/src/mongo/db/commands/find_cmd.cpp
@@ -133,7 +133,7 @@ public:
                    const BSONObj& cmdObj,
                    ExplainOptions::Verbosity verbosity,
                    BSONObjBuilder* out) const override {
-        const NamespaceString nss(parseNs(dbname, cmdObj));
+        const NamespaceString nss(parseNsCollectionRequired(dbname, cmdObj));
         if (!nss.isValid()) {
             return {ErrorCodes::InvalidNamespace,
                     str::stream() << "Invalid collection name: " << nss.ns()};
diff --git a/src/mongo/idl/idl_parser.cpp b/src/mongo/idl/idl_parser.cpp
index 9d4c139c9dc..fbcd93b5e4f 100644
--- a/src/mongo/idl/idl_parser.cpp
+++ b/src/mongo/idl/idl_parser.cpp
@@ -227,6 +227,12 @@ void IDLParserErrorContext::throwBadEnumValue(StringData enumValue) const {
 
 NamespaceString IDLParserErrorContext::parseNSCollectionRequired(StringData dbName,
                                                                  const BSONElement& element) {
+    const bool isUUID = (element.canonicalType() == canonicalizeBSONType(mongo::BinData) &&
+                         element.binDataType() == BinDataType::newUUID);
+    uassert(ErrorCodes::BadValue,
+            str::stream() << "Collection name must be provided. UUID is not valid in this "
+                          << "context",
+            !isUUID);
     uassert(ErrorCodes::BadValue,
             str::stream() << "collection name has invalid type " << typeName(element.type()),
             element.canonicalType() == canonicalizeBSONType(mongo::String));