On Thu, Sep 06, 2018 at 06:34:00AM -0400, Jamal Hadi Salim wrote:
> On 2018-09-06 6:28 a.m., Jamal Hadi Salim wrote:
> > On 2018-09-05 3:04 p.m., Al Viro wrote:
> > > From: Al Viro <[email protected]>
> > >
> > > ... and disallow deleting or linking to such
> > >
> > > Signed-off-by: Al Viro <[email protected]>
> >
> > Same comment as other one in regards to subject
> >
> > Since the flag space is coming from htnode which is
> > exposed via uapi it makes sense to keep this one here
> > because it is for private use; but a comment in
> > include/uapi/linux/pkt_cls.h that this flag or
> > maybe a set of bits is reserved for internal use.
> > Otherwise:
> >
> > Acked-by: Jamal Hadi Salim <[email protected]>
>
>
> Sorry, additional comment:
> It makes sense to reject user space attempt to
> set TCA_CLS_FLAGS_U32_ROOT
Point, and that one is IMO enough to give up on using ->flags for
that. How about simply
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 3f985f29ef30..d14048e38b5c 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -84,6 +84,7 @@ struct tc_u_hnode {
int refcnt;
unsigned int divisor;
struct idr handle_idr;
+ bool is_root;
struct rcu_head rcu;
u32 flags;
/* The 'ht' field MUST be the last field in structure to allow for
@@ -377,6 +378,7 @@ static int u32_init(struct tcf_proto *tp)
root_ht->refcnt++;
root_ht->handle = tp_c ? gen_new_htid(tp_c, root_ht) : 0x80000000;
root_ht->prio = tp->prio;
+ root_ht->is_root = true;
idr_init(&root_ht->handle_idr);
if (tp_c == NULL) {
@@ -693,7 +695,7 @@ static int u32_delete(struct tcf_proto *tp, void *arg, bool
*last,
goto out;
}
- if (root_ht == ht) {
+ if (ht->is_root) {
NL_SET_ERR_MSG_MOD(extack, "Not allowed to delete root node");
return -EINVAL;
}
@@ -795,6 +797,10 @@ static int u32_set_parms(struct net *net, struct tcf_proto
*tp,
NL_SET_ERR_MSG_MOD(extack, "Link hash table not
found");
return -EINVAL;
}
+ if (ht_down->is_root) {
+ NL_SET_ERR_MSG_MOD(extack, "Not linking to root
node");
+ return -EINVAL;
+ }
ht_down->refcnt++;
}
