core: Make support for "stateless stateids" configurable.

core/src/main/java/org/dcache/nfs/v4/NFSv4StateHandler.java

@@ -109,6 +109,8 @@ public class NFSv4StateHandler {
      */
     private final Clock _clock;
 
+    private boolean supportStateless = true;
+
     public NFSv4StateHandler() {
         this(Duration.ofSeconds(NFSv4Defaults.NFS4_LEASE_TIME), 0, new EphemeralClientRecoveryStore());
     }
@@ -500,4 +502,40 @@ public Duration getLeaseTime() {
         return _leaseTime;
     }
 
+    /**
+     * Checks if stateless stateids are supported.
+     * 
+     * @return true if supported.
+     */
+    public boolean isSupportStateless() {
+        return supportStateless;
+    }
+
+    /**
+     * Enables/disables support for stateless stateids.
+     * 
+     * @param supportStateless flag.
+     */
+    public void setSupportStateless(boolean supportStateless) {
+        this.supportStateless = supportStateless;
+    }
+
+    /**
+     * Checks if the given stateid is stateless. If so but stateless stateids are not supported, a
+     * {@link BadStateidException} is thrown.
+     * 
+     * @param stateid The stateid.
+     * @return {@code true} if stateless.
+     * @throws BadStateidException if stateless but not supported.
+     * @see #setSupportStateless(boolean)
+     */
+    public boolean checkStatelessAndSupported(stateid4 stateid) throws BadStateidException {
+        if (Stateids.isStateLess(stateid)) {
+            if (supportStateless) {
+                return true;
+            }
+            throw new BadStateidException();
+        }
+        return false;
+    }
 }

core/src/main/java/org/dcache/nfs/v4/OperationREAD.java

@@ -49,7 +49,9 @@ public void process(CompoundContext context, nfs_resop4 result) throws IOExcepti
 
         stateid4 stateid = Stateids.getCurrentStateidIfNeeded(context, _args.opread.stateid);
         var inode = context.currentInode();
-        if (Stateids.isStateLess(stateid)) {
+
+        NFSv4StateHandler stateHandler = context.getStateHandler();
+        if (stateHandler.checkStatelessAndSupported(stateid)) {
             // Anonymous access as per RFC 7530
             // https://datatracker.ietf.org/doc/html/rfc7530#section-9.1.4.3
             // we only check file access rights.
@@ -64,13 +66,13 @@ public void process(CompoundContext context, nfs_resop4 result) throws IOExcepti
                  *
                  * With introduction of sessions in v4.1 update of the lease time done through SEQUENCE operations.
                  */
-                context.getStateHandler().updateClientLeaseTime(stateid);
-                client = context.getStateHandler().getClientIdByStateId(stateid);
+                stateHandler.updateClientLeaseTime(stateid);
+                client = stateHandler.getClientIdByStateId(stateid);
             } else {
                 client = context.getSession().getClient();
             }
 
-            int shareAccess = context.getStateHandler().getFileTracker().getShareAccess(client, inode, stateid);
+            int shareAccess = stateHandler.getFileTracker().getShareAccess(client, inode, stateid);
             if ((shareAccess & nfs4_prot.OPEN4_SHARE_ACCESS_READ) == 0) {
                 throw new OpenModeException("Invalid open mode");
             }

core/src/main/java/org/dcache/nfs/v4/OperationWRITE.java

@@ -68,7 +68,8 @@ public void process(CompoundContext context, nfs_resop4 result) throws ChimeraNF
         }
 
         var inode = context.currentInode();
-        if (Stateids.isStateLess(stateid)) {
+        NFSv4StateHandler stateHandler = context.getStateHandler();
+        if (stateHandler.checkStatelessAndSupported(stateid)) {
             // Anonymous access as per RFC 7530
             // https://datatracker.ietf.org/doc/html/rfc7530#section-9.1.4.3
             // we only check file access rights.
@@ -85,13 +86,13 @@ public void process(CompoundContext context, nfs_resop4 result) throws ChimeraNF
                  *
                  * With introduction of sessions in v4.1 update of the lease time done through SEQUENCE operations.
                  */
-                context.getStateHandler().updateClientLeaseTime(stateid);
-                client = context.getStateHandler().getClientIdByStateId(stateid);
+                stateHandler.updateClientLeaseTime(stateid);
+                client = stateHandler.getClientIdByStateId(stateid);
             } else {
                 client = context.getSession().getClient();
             }
 
-            int shareAccess = context.getStateHandler().getFileTracker().getShareAccess(client, inode, stateid);
+            int shareAccess = stateHandler.getFileTracker().getShareAccess(client, inode, stateid);
             if ((shareAccess & nfs4_prot.OPEN4_SHARE_ACCESS_WRITE) == 0) {
                 throw new OpenModeException("Invalid open mode");
             }