ipv6: fib: Add FIB notifiers callbacks

We're about to add IPv6 FIB offload support, so implement the necessary
callbacks in IPv6 code, which will later allow us to add routes and
rules notifications.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 63 insertions, 1 deletions

diff --git a/net/ipv6/Makefile b/net/ipv6/Makefile
index 217e9ff0e24b..f8b24c2e0d77 100644
--- a/net/ipv6/Makefile
+++ b/net/ipv6/Makefile
@@ -9,7 +9,7 @@ ipv6-objs :=	af_inet6.o anycast.o ip6_output.o ip6_input.o addrconf.o \
 		route.o ip6_fib.o ipv6_sockglue.o ndisc.o udp.o udplite.o \
 		raw.o icmp.o mcast.o reassembly.o tcp_ipv6.o ping.o \
 		exthdrs.o datagram.o ip6_flowlabel.o inet6_connection_sock.o \
-		udp_offload.o seg6.o
+		udp_offload.o seg6.o fib6_notifier.o
 
 ipv6-offload :=	ip6_offload.o tcpv6_offload.o exthdrs_offload.o
 
diff --git a/net/ipv6/fib6_notifier.c b/net/ipv6/fib6_notifier.c
new file mode 100644
index 000000000000..c2bb1ab5b5eb
--- /dev/null
+++ b/net/ipv6/fib6_notifier.c
@@ -0,0 +1,55 @@
+#include <linux/notifier.h>
+#include <linux/socket.h>
+#include <linux/kernel.h>
+#include <net/net_namespace.h>
+#include <net/fib_notifier.h>
+#include <net/netns/ipv6.h>
+#include <net/ip6_fib.h>
+
+int call_fib6_notifier(struct notifier_block *nb, struct net *net,
+		       enum fib_event_type event_type,
+		       struct fib_notifier_info *info)
+{
+	info->family = AF_INET6;
+	return call_fib_notifier(nb, net, event_type, info);
+}
+
+int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
+			struct fib_notifier_info *info)
+{
+	info->family = AF_INET6;
+	return call_fib_notifiers(net, event_type, info);
+}
+
+static unsigned int fib6_seq_read(struct net *net)
+{
+	return 0;
+}
+
+static int fib6_dump(struct net *net, struct notifier_block *nb)
+{
+	return 0;
+}
+
+static const struct fib_notifier_ops fib6_notifier_ops_template = {
+	.family		= AF_INET6,
+	.fib_seq_read	= fib6_seq_read,
+	.fib_dump	= fib6_dump,
+};
+
+int __net_init fib6_notifier_init(struct net *net)
+{
+	struct fib_notifier_ops *ops;
+
+	ops = fib_notifier_ops_register(&fib6_notifier_ops_template, net);
+	if (IS_ERR(ops))
+		return PTR_ERR(ops);
+	net->ipv6.notifier_ops = ops;
+
+	return 0;
+}
+
+void __net_exit fib6_notifier_exit(struct net *net)
+{
+	fib_notifier_ops_unregister(net->ipv6.notifier_ops);
+}
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index ebb299cf72b7..f93976e3f65c 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -1839,6 +1839,11 @@ static void fib6_gc_timer_cb(unsigned long arg)
 static int __net_init fib6_net_init(struct net *net)
 {
 	size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
+	int err;
+
+	err = fib6_notifier_init(net);
+	if (err)
+		return err;
 
 	spin_lock_init(&net->ipv6.fib6_gc_lock);
 	rwlock_init(&net->ipv6.fib6_walker_lock);
@@ -1891,6 +1896,7 @@ out_fib_table_hash:
 out_rt6_stats:
 	kfree(net->ipv6.rt6_stats);
 out_timer:
+	fib6_notifier_exit(net);
 	return -ENOMEM;
 }
 
@@ -1907,6 +1913,7 @@ static void fib6_net_exit(struct net *net)
 	kfree(net->ipv6.fib6_main_tbl);
 	kfree(net->ipv6.fib_table_hash);
 	kfree(net->ipv6.rt6_stats);
+	fib6_notifier_exit(net);
 }
 
 static struct pernet_operations fib6_net_ops = {