net_sched: make cls_ops->change and cls_ops->delete optional

Some schedulers don't support creating, changing or deleting classes.
Make the respective callbacks optionally and consistently return
-EOPNOTSUPP for unsupported operations, instead of currently either
-EOPNOTSUPP, -ENOSYS or no error.

In case of sch_prio and sch_multiq, the removed operations additionally
checked for an invalid class. This is not necessary since the class
argument can only orginate from ->get() or in case of ->change is 0
for creation of new classes, in which case ->change() incorrectly
returned -ENOENT.

As a side-effect, this patch fixes a possible (root-only) NULL pointer
function call in sch_ingress, which didn't implement a so far mandatory
->delete() operation.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy
2009-09-04 06:41:16 +00:00
committed by David S. Miller
parent 71ebe5e919
commit de6d5cdf88
7 changed files with 6 additions and 85 deletions

View File

@@ -1417,7 +1417,9 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
goto out;
break;
case RTM_DELTCLASS:
err = cops->delete(q, cl);
err = -EOPNOTSUPP;
if (cops->delete)
err = cops->delete(q, cl);
if (err == 0)
tclass_notify(skb, n, q, cl, RTM_DELTCLASS);
goto out;
@@ -1431,7 +1433,9 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
}
new_cl = cl;
err = cops->change(q, clid, pid, tca, &new_cl);
err = -EOPNOTSUPP;
if (cops->change)
err = cops->change(q, clid, pid, tca, &new_cl);
if (err == 0)
tclass_notify(skb, n, q, new_cl, RTM_NEWTCLASS);