diff options
Diffstat (limited to '')
| -rw-r--r-- | net/sched/cls_api.c | 241 |
1 files changed, 149 insertions, 92 deletions
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index e8ed461e94af..5f9373ee47ce 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -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); } |