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Diffstat (limited to 'net/sched/sch_api.c')
-rw-r--r--net/sched/sch_api.c99
1 files changed, 74 insertions, 25 deletions
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 6f36df85d23d..d07146a2d0bb 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -298,7 +298,7 @@ struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
if (!handle)
return NULL;
- q = qdisc_match_from_root(dev->qdisc, handle);
+ q = qdisc_match_from_root(rtnl_dereference(dev->qdisc), handle);
if (q)
goto out;
@@ -317,7 +317,7 @@ struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle)
if (!handle)
return NULL;
- q = qdisc_match_from_root(dev->qdisc, handle);
+ q = qdisc_match_from_root(rcu_dereference(dev->qdisc), handle);
if (q)
goto out;
@@ -1071,11 +1071,12 @@ static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
skip:
if (!ingress) {
- notify_and_destroy(net, skb, n, classid,
- dev->qdisc, new);
+ old = rtnl_dereference(dev->qdisc);
if (new && !new->ops->attach)
qdisc_refcount_inc(new);
- dev->qdisc = new ? : &noop_qdisc;
+ rcu_assign_pointer(dev->qdisc, new ? : &noop_qdisc);
+
+ notify_and_destroy(net, skb, n, classid, old, new);
if (new && new->ops->attach)
new->ops->attach(new);
@@ -1104,6 +1105,11 @@ skip:
return -ENOENT;
}
+ if (new && new->ops == &noqueue_qdisc_ops) {
+ NL_SET_ERR_MSG(extack, "Cannot assign noqueue to a class");
+ return -EINVAL;
+ }
+
err = cops->graft(parent, cl, new, &old, extack);
if (err)
return err;
@@ -1208,7 +1214,12 @@ static struct Qdisc *qdisc_create(struct net_device *dev,
sch->parent = parent;
if (handle == TC_H_INGRESS) {
- sch->flags |= TCQ_F_INGRESS;
+ if (!(sch->flags & TCQ_F_INGRESS)) {
+ NL_SET_ERR_MSG(extack,
+ "Specified parent ID is reserved for ingress and clsact Qdiscs");
+ err = -EINVAL;
+ goto err_out3;
+ }
handle = TC_H_MAKE(TC_H_INGRESS, 0);
} else {
if (handle == 0) {
@@ -1450,7 +1461,7 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
q = dev_ingress_queue(dev)->qdisc_sleeping;
}
} else {
- q = dev->qdisc;
+ q = rtnl_dereference(dev->qdisc);
}
if (!q) {
NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device");
@@ -1492,10 +1503,28 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
return 0;
}
+static bool req_create_or_replace(struct nlmsghdr *n)
+{
+ return (n->nlmsg_flags & NLM_F_CREATE &&
+ n->nlmsg_flags & NLM_F_REPLACE);
+}
+
+static bool req_create_exclusive(struct nlmsghdr *n)
+{
+ return (n->nlmsg_flags & NLM_F_CREATE &&
+ n->nlmsg_flags & NLM_F_EXCL);
+}
+
+static bool req_change(struct nlmsghdr *n)
+{
+ return (!(n->nlmsg_flags & NLM_F_CREATE) &&
+ !(n->nlmsg_flags & NLM_F_REPLACE) &&
+ !(n->nlmsg_flags & NLM_F_EXCL));
+}
+
/*
* Create/change qdisc.
*/
-
static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
struct netlink_ext_ack *extack)
{
@@ -1539,7 +1568,7 @@ replay:
q = dev_ingress_queue(dev)->qdisc_sleeping;
}
} else {
- q = dev->qdisc;
+ q = rtnl_dereference(dev->qdisc);
}
/* It may be default qdisc, ignore it */
@@ -1568,11 +1597,20 @@ replay:
NL_SET_ERR_MSG(extack, "Invalid qdisc name");
return -EINVAL;
}
+ if (q->flags & TCQ_F_INGRESS) {
+ NL_SET_ERR_MSG(extack,
+ "Cannot regraft ingress or clsact Qdiscs");
+ return -EINVAL;
+ }
if (q == p ||
(p && check_loop(q, p, 0))) {
NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected");
return -ELOOP;
}
+ if (clid == TC_H_INGRESS) {
+ NL_SET_ERR_MSG(extack, "Ingress cannot graft directly");
+ return -EINVAL;
+ }
qdisc_refcount_inc(q);
goto graft;
} else {
@@ -1583,27 +1621,35 @@ replay:
*
* We know, that some child q is already
* attached to this parent and have choice:
- * either to change it or to create/graft new one.
+ * 1) change it or 2) create/graft new one.
+ * If the requested qdisc kind is different
+ * than the existing one, then we choose graft.
+ * If they are the same then this is "change"
+ * operation - just let it fallthrough..
*
* 1. We are allowed to create/graft only
- * if CREATE and REPLACE flags are set.
+ * if the request is explicitly stating
+ * "please create if it doesn't exist".
*
- * 2. If EXCL is set, requestor wanted to say,
- * that qdisc tcm_handle is not expected
+ * 2. If the request is to exclusive create
+ * then the qdisc tcm_handle is not expected
* to exist, so that we choose create/graft too.
*
* 3. The last case is when no flags are set.
+ * This will happen when for example tc
+ * utility issues a "change" command.
* Alas, it is sort of hole in API, we
* cannot decide what to do unambiguously.
- * For now we select create/graft, if
- * user gave KIND, which does not match existing.
+ * For now we select create/graft.
*/
- if ((n->nlmsg_flags & NLM_F_CREATE) &&
- (n->nlmsg_flags & NLM_F_REPLACE) &&
- ((n->nlmsg_flags & NLM_F_EXCL) ||
- (tca[TCA_KIND] &&
- nla_strcmp(tca[TCA_KIND], q->ops->id))))
- goto create_n_graft;
+ if (tca[TCA_KIND] &&
+ nla_strcmp(tca[TCA_KIND], q->ops->id)) {
+ if (req_create_or_replace(n) ||
+ req_create_exclusive(n))
+ goto create_n_graft;
+ else if (req_change(n))
+ goto create_n_graft2;
+ }
}
}
} else {
@@ -1637,6 +1683,7 @@ create_n_graft:
NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag");
return -ENOENT;
}
+create_n_graft2:
if (clid == TC_H_INGRESS) {
if (dev_ingress_queue(dev)) {
q = qdisc_create(dev, dev_ingress_queue(dev), p,
@@ -1761,7 +1808,8 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
s_q_idx = 0;
q_idx = 0;
- if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx,
+ if (tc_dump_qdisc_root(rtnl_dereference(dev->qdisc),
+ skb, cb, &q_idx, s_q_idx,
true, tca[TCA_DUMP_INVISIBLE]) < 0)
goto done;
@@ -2037,7 +2085,7 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
} else if (qid1) {
qid = qid1;
} else if (qid == 0)
- qid = dev->qdisc->handle;
+ qid = rtnl_dereference(dev->qdisc)->handle;
/* Now qid is genuine qdisc handle consistent
* both with parent and child.
@@ -2048,7 +2096,7 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
portid = TC_H_MAKE(qid, portid);
} else {
if (qid == 0)
- qid = dev->qdisc->handle;
+ qid = rtnl_dereference(dev->qdisc)->handle;
}
/* OK. Locate qdisc */
@@ -2209,7 +2257,8 @@ static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
s_t = cb->args[0];
t = 0;
- if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t, true) < 0)
+ if (tc_dump_tclass_root(rtnl_dereference(dev->qdisc),
+ skb, tcm, cb, &t, s_t, true) < 0)
goto done;
dev_queue = dev_ingress_queue(dev);