sunrpc: parse and return errors reported by gssd
The kernel currently ignores any error code sent by gssd and always
considers it to be -EACCES. In order to better handle the situation of
an expired KRB5 TGT, the kernel needs to be able to parse and deal with
the errors that gssd sends. Aside from -EACCES the only error we care
about is -EKEYEXPIRED, which we're using to indicate that the upper
layers should retry the call a little later.
To maintain backward compatibility with older gssd's, any error other
than -EKEYEXPIRED is interpreted as -EACCES.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index f7a7f83..0cfccc2a 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -206,8 +206,14 @@
ctx->gc_win = window_size;
/* gssd signals an error by passing ctx->gc_win = 0: */
if (ctx->gc_win == 0) {
- /* in which case, p points to an error code which we ignore */
- p = ERR_PTR(-EACCES);
+ /*
+ * in which case, p points to an error code. Anything other
+ * than -EKEYEXPIRED gets converted to -EACCES.
+ */
+ p = simple_get_bytes(p, end, &ret, sizeof(ret));
+ if (!IS_ERR(p))
+ p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
+ ERR_PTR(-EACCES);
goto err;
}
/* copy the opaque wire context */
@@ -646,6 +652,7 @@
err = PTR_ERR(p);
switch (err) {
case -EACCES:
+ case -EKEYEXPIRED:
gss_msg->msg.errno = err;
err = mlen;
break;
