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>
This commit is contained in:
Jeff Layton 2010-01-07 09:42:02 -05:00 committed by Trond Myklebust
parent ac73fddfc5
commit dc5ddce956
1 changed files with 9 additions and 2 deletions

View File

@ -206,8 +206,14 @@ gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct
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 @@ gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
err = PTR_ERR(p);
switch (err) {
case -EACCES:
case -EKEYEXPIRED:
gss_msg->msg.errno = err;
err = mlen;
break;