@@ -1101,6 +1101,142 @@ static void tcf_block_flush_all_chains(struct tcf_block *block, bool rtnl_held)
}
}
+/* Lookup Qdisc and increments its reference counter.
+ * Set parent, if necessary.
+ */
+
+static int __tcf_qdisc_find(struct net *net, struct Qdisc **q,
+ u32 *parent, int ifindex, bool rtnl_held,
+ struct netlink_ext_ack *extack)
+{
+ const struct Qdisc_class_ops *cops;
+ struct net_device *dev;
+ int err = 0;
+
+ if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
+ return 0;
+
+ rcu_read_lock();
+
+ /* Find link */
+ dev = dev_get_by_index_rcu(net, ifindex);
+ if (!dev) {
+ rcu_read_unlock();
+ return -ENODEV;
+ }
+
+ /* Find qdisc */
+ if (!*parent) {
+ *q = dev->qdisc;
+ *parent = (*q)->handle;
+ } else {
+ *q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
+ if (!*q) {
+ NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
+ err = -EINVAL;
+ goto errout_rcu;
+ }
+ }
+
+ *q = qdisc_refcount_inc_nz(*q);
+ if (!*q) {
+ NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
+ err = -EINVAL;
+ goto errout_rcu;
+ }
+
+ /* Is it classful? */
+ cops = (*q)->ops->cl_ops;
+ if (!cops) {
+ NL_SET_ERR_MSG(extack, "Qdisc not classful");
+ err = -EINVAL;
+ goto errout_qdisc;
+ }
+
+ if (!cops->tcf_block) {
+ NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
+ err = -EOPNOTSUPP;
+ goto errout_qdisc;
+ }
+
+errout_rcu:
+ /* At this point we know that qdisc is not noop_qdisc,
+ * which means that qdisc holds a reference to net_device
+ * and we hold a reference to qdisc, so it is safe to release
+ * rcu read lock.
+ */
+ rcu_read_unlock();
+ return err;
+
+errout_qdisc:
+ rcu_read_unlock();
+
+ if (rtnl_held)
+ qdisc_put(*q);
+ else
+ qdisc_put_unlocked(*q);
+ *q = NULL;
+
+ return err;
+}
+
+static int __tcf_qdisc_cl_find(struct Qdisc *q, u32 parent, unsigned long *cl,
+ int ifindex, struct netlink_ext_ack *extack)
+{
+ if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
+ return 0;
+
+ /* Do we search for filter, attached to class? */
+ if (TC_H_MIN(parent)) {
+ const struct Qdisc_class_ops *cops = q->ops->cl_ops;
+
+ *cl = cops->find(q, parent);
+ if (*cl == 0) {
+ NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
+ return -ENOENT;
+ }
+ }
+
+ return 0;
+}
+
+static struct tcf_block *__tcf_block_find(struct net *net, struct Qdisc *q,
+ unsigned long cl, int ifindex,
+ u32 block_index,
+ struct netlink_ext_ack *extack)
+{
+ struct tcf_block *block;
+
+ if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
+ block = tcf_block_refcnt_get(net, block_index);
+ if (!block) {
+ NL_SET_ERR_MSG(extack, "Block of given index was not found");
+ return ERR_PTR(-EINVAL);
+ }
+ } else {
+ const struct Qdisc_class_ops *cops = q->ops->cl_ops;
+
+ block = cops->tcf_block(q, cl, extack);
+ if (!block)
+ return ERR_PTR(-EINVAL);
+
+ if (tcf_block_shared(block)) {
+ NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
+ return ERR_PTR(-EOPNOTSUPP);
+ }
+
+ /* Always take reference to block in order to support execution
+ * of rules update path of cls API without rtnl lock. Caller
+ * must release block when it is finished using it. 'if' block
+ * of this conditional obtain reference to block by calling
+ * tcf_block_refcnt_get().
+ */
+ refcount_inc(&block->refcnt);
+ }
+
+ return block;
+}
+
static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
struct tcf_block_ext_info *ei, bool rtnl_held)
{
@@ -1146,106 +1282,27 @@ static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
struct tcf_block *block;
int err = 0;
- if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
- block = tcf_block_refcnt_get(net, block_index);
- if (!block) {
- NL_SET_ERR_MSG(extack, "Block of given index was not found");
- return ERR_PTR(-EINVAL);
- }
- } else {
- const struct Qdisc_class_ops *cops;
- struct net_device *dev;
-
- rcu_read_lock();
-
- /* Find link */
- dev = dev_get_by_index_rcu(net, ifindex);
- if (!dev) {
- rcu_read_unlock();
- return ERR_PTR(-ENODEV);
- }
-
- /* Find qdisc */
- if (!*parent) {
- *q = dev->qdisc;
- *parent = (*q)->handle;
- } else {
- *q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
- if (!*q) {
- NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
- err = -EINVAL;
- goto errout_rcu;
- }
- }
-
- *q = qdisc_refcount_inc_nz(*q);
- if (!*q) {
- NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
- err = -EINVAL;
- goto errout_rcu;
- }
-
- /* Is it classful? */
- cops = (*q)->ops->cl_ops;
- if (!cops) {
- NL_SET_ERR_MSG(extack, "Qdisc not classful");
- err = -EINVAL;
- goto errout_rcu;
- }
-
- if (!cops->tcf_block) {
- NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
- err = -EOPNOTSUPP;
- goto errout_rcu;
- }
-
- /* At this point we know that qdisc is not noop_qdisc,
- * which means that qdisc holds a reference to net_device
- * and we hold a reference to qdisc, so it is safe to release
- * rcu read lock.
- */
- rcu_read_unlock();
+ ASSERT_RTNL();
- /* Do we search for filter, attached to class? */
- if (TC_H_MIN(*parent)) {
- *cl = cops->find(*q, *parent);
- if (*cl == 0) {
- NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
- err = -ENOENT;
- goto errout_qdisc;
- }
- }
+ err = __tcf_qdisc_find(net, q, parent, ifindex, true, extack);
+ if (err)
+ goto errout;
- /* And the last stroke */
- block = cops->tcf_block(*q, *cl, extack);
- if (!block) {
- err = -EINVAL;
- goto errout_qdisc;
- }
- if (tcf_block_shared(block)) {
- NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
- err = -EOPNOTSUPP;
- goto errout_qdisc;
- }
+ err = __tcf_qdisc_cl_find(*q, *parent, cl, ifindex, extack);
+ if (err)
+ goto errout_qdisc;
- /* Always take reference to block in order to support execution
- * of rules update path of cls API without rtnl lock. Caller
- * must release block when it is finished using it. 'if' block
- * of this conditional obtain reference to block by calling
- * tcf_block_refcnt_get().
- */
- refcount_inc(&block->refcnt);
- }
+ block = __tcf_block_find(net, *q, *cl, ifindex, block_index, extack);
+ if (IS_ERR(block))
+ goto errout_qdisc;
return block;
-errout_rcu:
- rcu_read_unlock();
errout_qdisc:
- if (*q) {
+ if (*q)
qdisc_put(*q);
- *q = NULL;
- }
+errout:
+ *q = NULL;
return ERR_PTR(err);
}