kgss: de-virtualize kgss_gssd_handle

The RPC client is more of a class rather than an instance.  RPCs from
different VNETs are served by the same client.  This makes the kgss layer
fully transparent to VIMAGE and not even required to be aware of it.

It is responsibility of the rpcsec_gss module to have curvnet set on the
calling thread when doing RPC calls via kgssapi.

This change should enable proper operation of an NFS server with gssd(8)
in a VIMAGE jail.

PR:			294501
Reviewed by:		rmacklem
Differential Revision:	https://reviews.freebsd.org/D56562

1 files changed, 5 insertions, 19 deletions

diff --git a/sys/kgssapi/gss_impl.c b/sys/kgssapi/gss_impl.c
index e7e0e5d00118..97b85a034071 100644
--- a/sys/kgssapi/gss_impl.c
+++ b/sys/kgssapi/gss_impl.c
@@ -28,7 +28,6 @@
  */
 
 #include <sys/param.h>
-#include <sys/jail.h>
 #include <sys/kernel.h>
 #include <sys/kobj.h>
 #include <sys/lock.h>
@@ -52,7 +51,7 @@ MALLOC_DEFINE(M_GSSAPI, "GSS-API", "GSS-API");
 struct kgss_mech_list kgss_mechs;
 struct mtx kgss_gssd_lock;
 
-VNET_DEFINE(CLIENT *, kgss_gssd_handle) = NULL;
+CLIENT *kgss_gssd_handle;
 
 static int
 kgss_load(void)
@@ -79,11 +78,9 @@ kgss_load(void)
 	 */
 	clnt_control(cl, CLSET_WAITCHAN, "gssd");
 
-	CURVNET_SET_QUIET(TD_TO_VNET(curthread));
 	mtx_lock(&kgss_gssd_lock);
-	VNET(kgss_gssd_handle) = cl;
+	kgss_gssd_handle = cl;
 	mtx_unlock(&kgss_gssd_lock);
-	CURVNET_RESTORE();
 
 	return (0);
 }
@@ -93,9 +90,7 @@ static void
 kgss_unload(void)
 {
 
-	CURVNET_SET_QUIET(TD_TO_VNET(curthread));
-	clnt_destroy(VNET(kgss_gssd_handle));
-	CURVNET_RESTORE();
+	clnt_destroy(kgss_gssd_handle);
 }
 #endif
 
@@ -207,16 +202,9 @@ kgss_transfer_context(gss_ctx_id_t ctx, void *lctx)
 		return (maj_stat);
 	}
 
-	CURVNET_SET_QUIET(TD_TO_VNET(curthread));
-	if (!VNET(kgss_gssd_handle)) {
-		CURVNET_RESTORE();
-		return (GSS_S_FAILURE);
-	}
-
 	args.ctx = ctx->handle;
 	bzero(&res, sizeof(res));
-	stat = gssd_export_sec_context_1(&args, &res, VNET(kgss_gssd_handle));
-	CURVNET_RESTORE();
+	stat = gssd_export_sec_context_1(&args, &res, kgss_gssd_handle);
 	if (stat != RPC_SUCCESS) {
 		return (GSS_S_FAILURE);
 	}
@@ -250,13 +238,11 @@ kgss_gssd_client(void)
 {
 	CLIENT *cl;
 
-	CURVNET_SET_QUIET(TD_TO_VNET(curthread));
 	mtx_lock(&kgss_gssd_lock);
-	cl = VNET(kgss_gssd_handle);
+	cl = kgss_gssd_handle;
 	if (cl != NULL)
 		CLNT_ACQUIRE(cl);
 	mtx_unlock(&kgss_gssd_lock);
-	CURVNET_RESTORE();
 	return (cl);
 }