SERVER-22577 disallow creation of databases containing $ on mmapv1

1 files changed, 19 insertions, 6 deletions

diff --git a/src/mongo/db/namespace_string.h b/src/mongo/db/namespace_string.h
index 5a891df19c0..65d23736dee 100644
--- a/src/mongo/db/namespace_string.h
+++ b/src/mongo/db/namespace_string.h
@@ -96,6 +96,16 @@ public:
         MaxNsCollectionLen = MaxNsLen - 7 /*strlen(".$extra")*/,
     };
 
+    /**
+     * DollarInDbNameBehavior::allow is deprecated.
+     * Please use DollarInDbNameBehavior::disallow and check explicitly for any DB names that must
+     * contain a $.
+     */
+    enum class DollarInDbNameBehavior {
+        Disallow,
+        Allow,  // Deprecated
+    };
+
     StringData db() const;
     StringData coll() const;
 
@@ -165,7 +175,7 @@ public:
      * valid.
      */
     bool isValid() const {
-        return validDBName(db()) && !coll().empty();
+        return validDBName(db(), DollarInDbNameBehavior::Allow) && !coll().empty();
     }
 
     bool operator==(const std::string& nsIn) const {
@@ -220,12 +230,12 @@ public:
     /**
      * Returns true for DBs with special meaning to mongodb.
      */
-    static bool internalDb(StringData ns) {
-        if (ns == "admin")
+    static bool internalDb(StringData db) {
+        if (db == "admin")
             return true;
-        if (ns == "local")
+        if (db == "local")
             return true;
-        if (ns == "config")
+        if (db == "config")
             return true;
         return false;
     }
@@ -242,9 +252,12 @@ public:
      *      foo"bar
      *
      * @param db - a possible database name
+     * @param DollarInDbNameBehavior - please do not change the default value. DB names that must
+     *                                 contain a $ should be checked explicitly.
      * @return if db is an allowed database name
      */
-    static bool validDBName(StringData dbin);
+    static bool validDBName(StringData db,
+                            DollarInDbNameBehavior behavior = DollarInDbNameBehavior::Disallow);
 
     /**
      * Takes a fully qualified namespace (ie dbname.collectionName), and returns true if