diff mbox series

[net-next,10/18] nexthop: Emit a notification when a nexthop group is modified

Message ID 20201104133040.1125369-11-idosch@idosch.org (mailing list archive)
State Not Applicable
Delegated to: Netdev Maintainers
Headers show
Series nexthop: Add support for nexthop objects offload | expand

Commit Message

Ido Schimmel Nov. 4, 2020, 1:30 p.m. UTC 
From: Ido Schimmel <idosch@nvidia.com>

When a single nexthop is replaced, the configuration of all the groups
using the nexthop is effectively modified. In this case, emit a
notification in the nexthop notification chain for each modified group
so that listeners would not need to keep track of which nexthops are
member in which groups.

The notification can only be emitted after the new configuration (i.e.,
'struct nh_info') is pointed at by the old shell (i.e., 'struct
nexthop'). Before that the configuration of the nexthop groups is still
the same as before the replacement.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
---
 net/ipv4/nexthop.c | 32 ++++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index 11bfb1eb7f84..0e8e753956f1 100644
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -1099,7 +1099,9 @@  static int replace_nexthop_single(struct net *net, struct nexthop *old,
 				  struct nexthop *new,
 				  struct netlink_ext_ack *extack)
 {
+	u8 old_protocol, old_nh_flags;
 	struct nh_info *oldi, *newi;
+	struct nh_grp_entry *nhge;
 	int err;
 
 	if (new->is_group) {
@@ -1122,18 +1124,29 @@  static int replace_nexthop_single(struct net *net, struct nexthop *old,
 	newi->nh_parent = old;
 	oldi->nh_parent = new;
 
+	old_protocol = old->protocol;
+	old_nh_flags = old->nh_flags;
+
 	old->protocol = new->protocol;
 	old->nh_flags = new->nh_flags;
 
 	rcu_assign_pointer(old->nh_info, newi);
 	rcu_assign_pointer(new->nh_info, oldi);
 
+	/* Send a replace notification for all the groups using the nexthop. */
+	list_for_each_entry(nhge, &old->grp_list, nh_list) {
+		struct nexthop *nhp = nhge->nh_parent;
+
+		err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, nhp,
+					     extack);
+		if (err)
+			goto err_notify;
+	}
+
 	/* When replacing an IPv4 nexthop with an IPv6 nexthop, potentially
 	 * update IPv4 indication in all the groups using the nexthop.
 	 */
 	if (oldi->family == AF_INET && newi->family == AF_INET6) {
-		struct nh_grp_entry *nhge;
-
 		list_for_each_entry(nhge, &old->grp_list, nh_list) {
 			struct nexthop *nhp = nhge->nh_parent;
 			struct nh_group *nhg;
@@ -1144,6 +1157,21 @@  static int replace_nexthop_single(struct net *net, struct nexthop *old,
 	}
 
 	return 0;
+
+err_notify:
+	rcu_assign_pointer(new->nh_info, newi);
+	rcu_assign_pointer(old->nh_info, oldi);
+	old->nh_flags = old_nh_flags;
+	old->protocol = old_protocol;
+	oldi->nh_parent = old;
+	newi->nh_parent = new;
+	list_for_each_entry_continue_reverse(nhge, &old->grp_list, nh_list) {
+		struct nexthop *nhp = nhge->nh_parent;
+
+		call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, nhp, extack);
+	}
+	call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, old, extack);
+	return err;
 }
 
 static void __nexthop_replace_notify(struct net *net, struct nexthop *nh,