Horatiu Vultur
2020-May-20  13:09 UTC
[Bridge] [PATCH 1/3] bridge: mrp: Add br_mrp_unique_ifindex function
It is not allow to have the same net bridge port part of multiple MRP
rings. Therefore add a check if the port is used already in a different
MRP. In that case return failure.
Fixes: 9a9f26e8f7ea ("bridge: mrp: Connect MRP API with the switchdev
API")
Signed-off-by: Horatiu Vultur <horatiu.vultur at microchip.com>
---
 net/bridge/br_mrp.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
diff --git a/net/bridge/br_mrp.c b/net/bridge/br_mrp.c
index d7bc09de4c139..a5a3fa59c078a 100644
--- a/net/bridge/br_mrp.c
+++ b/net/bridge/br_mrp.c
@@ -37,6 +37,32 @@ static struct br_mrp *br_mrp_find_id(struct net_bridge *br,
u32 ring_id)
 	return res;
 }
 
+static bool br_mrp_unique_ifindex(struct net_bridge *br, u32 ifindex)
+{
+	struct br_mrp *mrp;
+	bool res = true;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(mrp, &br->mrp_list, list,
+				lockdep_rtnl_is_held()) {
+		struct net_bridge_port *p;
+
+		p = rcu_dereference(mrp->p_port);
+		if (p && p->dev->ifindex == ifindex) {
+			res = false;
+			break;
+		}
+
+		p = rcu_dereference(mrp->s_port);
+		if (p && p->dev->ifindex == ifindex) {
+			res = false;
+			break;
+		}
+	}
+	rcu_read_unlock();
+	return res;
+}
+
 static struct br_mrp *br_mrp_find_port(struct net_bridge *br,
 				       struct net_bridge_port *p)
 {
@@ -255,6 +281,11 @@ int br_mrp_add(struct net_bridge *br, struct
br_mrp_instance *instance)
 	    !br_mrp_get_port(br, instance->s_ifindex))
 		return -EINVAL;
 
+	/* It is not possible to have the same port part of multiple rings */
+	if (!br_mrp_unique_ifindex(br, instance->p_ifindex) ||
+	    !br_mrp_unique_ifindex(br, instance->s_ifindex))
+		return -EINVAL;
+
 	mrp = kzalloc(sizeof(*mrp), GFP_KERNEL);
 	if (!mrp)
 		return -ENOMEM;
-- 
2.26.2
Nikolay Aleksandrov
2020-May-21  08:16 UTC
[Bridge] [PATCH 1/3] bridge: mrp: Add br_mrp_unique_ifindex function
On 20/05/2020 16:09, Horatiu Vultur wrote:> It is not allow to have the same net bridge port part of multiple MRP > rings. Therefore add a check if the port is used already in a different > MRP. In that case return failure. > > Fixes: 9a9f26e8f7ea ("bridge: mrp: Connect MRP API with the switchdev API") > Signed-off-by: Horatiu Vultur <horatiu.vultur at microchip.com> > --- > net/bridge/br_mrp.c | 31 +++++++++++++++++++++++++++++++ > 1 file changed, 31 insertions(+) > > diff --git a/net/bridge/br_mrp.c b/net/bridge/br_mrp.c > index d7bc09de4c139..a5a3fa59c078a 100644 > --- a/net/bridge/br_mrp.c > +++ b/net/bridge/br_mrp.c > @@ -37,6 +37,32 @@ static struct br_mrp *br_mrp_find_id(struct net_bridge *br, u32 ring_id) > return res; > } > > +static bool br_mrp_unique_ifindex(struct net_bridge *br, u32 ifindex) > +{ > + struct br_mrp *mrp; > + bool res = true; > + > + rcu_read_lock();Why do you need the rcu_read_lock() here when lockdep_rtnl_is_held() is used? You should be able to just do rtnl_dereference() below as this is used only under rtnl.> + list_for_each_entry_rcu(mrp, &br->mrp_list, list, > + lockdep_rtnl_is_held()) { > + struct net_bridge_port *p; > + > + p = rcu_dereference(mrp->p_port); > + if (p && p->dev->ifindex == ifindex) { > + res = false; > + break; > + } > + > + p = rcu_dereference(mrp->s_port); > + if (p && p->dev->ifindex == ifindex) { > + res = false; > + break; > + } > + } > + rcu_read_unlock(); > + return res; > +} > + > static struct br_mrp *br_mrp_find_port(struct net_bridge *br, > struct net_bridge_port *p) > { > @@ -255,6 +281,11 @@ int br_mrp_add(struct net_bridge *br, struct br_mrp_instance *instance) > !br_mrp_get_port(br, instance->s_ifindex)) > return -EINVAL; > > + /* It is not possible to have the same port part of multiple rings */ > + if (!br_mrp_unique_ifindex(br, instance->p_ifindex) || > + !br_mrp_unique_ifindex(br, instance->s_ifindex)) > + return -EINVAL; > + > mrp = kzalloc(sizeof(*mrp), GFP_KERNEL); > if (!mrp) > return -ENOMEM; >