smb2_tcon: add "smb3 share cap:{CONTINUOUS AVAILABILITY,SCALE OUT,CLUSTER,ASYMMETRIC...

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Günther Deschner <gd@samba.org>
Autobuild-User(master): Stefan Metzmacher <metze@samba.org>
Autobuild-Date(master): Fri Jan 26 18:04:10 UTC 2024 on atb-devel-224

diff --git a/source3/smbd/smb2_tcon.c b/source3/smbd/smb2_tcon.c
index 5bd01c77e053fb62c569ae23edbcb9e7b154963f..fca35e36ce5cc8cc6664d8d9a7ad2009fe8f45b0 100644 (file)
--- a/source3/smbd/smb2_tcon.c
+++ b/source3/smbd/smb2_tcon.c
@@ -421,6 +421,78 @@ static NTSTATUS smbd_smb2_tree_connect(struct smbd_smb2_request *req,
                *out_share_flags |= SMB2_SHAREFLAG_ENCRYPT_DATA;
        }
 
+       /*
+        * For disk shares we can change the client
+        * behavior on a cluster...
+        */
+       if (*out_share_type == SMB2_SHARE_TYPE_DISK) {
+               bool persistent = false; /* persistent handles not implemented yet */
+               bool cluster = lp_clustering();
+               bool asymmetric = false; /* shares are symmetric by default */
+               bool announce;
+
+               /*
+                * In a ctdb cluster shares are continuously available,
+                * but windows clients mix this with the global persistent
+                * handles support.
+                *
+                * Persistent handles are requested if
+                * SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY is present
+                * even without SMB2_CAP_PERSISTENT_HANDLES.
+                *
+                * And SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY is
+                * required for SMB2_SHARE_CAP_CLUSTER to have
+                * an effect.
+                *
+                * So we better don't announce this by default
+                * until we support persistent handles.
+                */
+               announce = lp_parm_bool(SNUM(tcon->compat),
+                                       "smb3 share cap",
+                                       "CONTINUOUS AVAILABILITY",
+                                       persistent);
+               if (announce) {
+                       *out_capabilities |= SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY;
+               }
+
+               /*
+                * ctdb clusters are always scale out...
+                */
+               announce = lp_parm_bool(SNUM(tcon->compat),
+                                       "smb3 share cap",
+                                       "SCALE OUT",
+                                       cluster);
+               if (announce) {
+                       *out_capabilities |= SMB2_SHARE_CAP_SCALEOUT;
+               }
+
+               /*
+                * We support the witness service when ctdb is active
+                */
+               announce = lp_parm_bool(SNUM(tcon->compat),
+                                       "smb3 share cap",
+                                       "CLUSTER",
+                                       cluster);
+               if (announce) {
+                       *out_capabilities |= SMB2_SHARE_CAP_CLUSTER;
+               }
+
+               /*
+                * Shares in a ctdb cluster are symmetric by design.
+                *
+                * But it might be useful to let the client use
+                * an isolated transport and witness registration for the
+                * specific share.
+                */
+               announce = lp_parm_bool(SNUM(tcon->compat),
+                                       "smb3 share cap",
+                                       "ASYMMETRIC",
+                                       asymmetric);
+               if (announce) {
+                       *out_capabilities |= SMB2_SHARE_CAP_ASYMMETRIC;
+               }
+       }
+
        *out_maximal_access = tcon->compat->share_access;
 
        *out_tree_id = tcon->global->tcon_wire_id;