1 files changed, 272 insertions, 0 deletions
diff --git a/drivers/net/vxlan/vxlan_multicast.c b/drivers/net/vxlan/vxlan_multicast.c
new file mode 100644
index 000000000000..a7f2d67dc61b
--- /dev/null
+++ b/drivers/net/vxlan/vxlan_multicast.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *	Vxlan multicast group handling
+ *
+ */
+#include <linux/kernel.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+#include <linux/igmp.h>
+#include <net/vxlan.h>
+
+#include "vxlan_private.h"
+
+/* Update multicast group membership when first VNI on
+ * multicast address is brought up
+ */
+int vxlan_igmp_join(struct vxlan_dev *vxlan, union vxlan_addr *rip,
+		    int rifindex)
+{
+	union vxlan_addr *ip = (rip ? : &vxlan->default_dst.remote_ip);
+	int ifindex = (rifindex ? : vxlan->default_dst.remote_ifindex);
+	int ret = -EINVAL;
+	struct sock *sk;
+
+	if (ip->sa.sa_family == AF_INET) {
+		struct vxlan_sock *sock4 = rtnl_dereference(vxlan->vn4_sock);
+		struct ip_mreqn mreq = {
+			.imr_multiaddr.s_addr	= ip->sin.sin_addr.s_addr,
+			.imr_ifindex		= ifindex,
+		};
+
+		sk = sock4->sock->sk;
+		lock_sock(sk);
+		ret = ip_mc_join_group(sk, &mreq);
+		release_sock(sk);
+#if IS_ENABLED(CONFIG_IPV6)
+	} else {
+		struct vxlan_sock *sock6 = rtnl_dereference(vxlan->vn6_sock);
+
+		sk = sock6->sock->sk;
+		lock_sock(sk);
+		ret = ipv6_stub->ipv6_sock_mc_join(sk, ifindex,
+						   &ip->sin6.sin6_addr);
+		release_sock(sk);
+#endif
+	}
+
+	return ret;
+}
+
+int vxlan_igmp_leave(struct vxlan_dev *vxlan, union vxlan_addr *rip,
+		     int rifindex)
+{
+	union vxlan_addr *ip = (rip ? : &vxlan->default_dst.remote_ip);
+	int ifindex = (rifindex ? : vxlan->default_dst.remote_ifindex);
+	int ret = -EINVAL;
+	struct sock *sk;
+
+	if (ip->sa.sa_family == AF_INET) {
+		struct vxlan_sock *sock4 = rtnl_dereference(vxlan->vn4_sock);
+		struct ip_mreqn mreq = {
+			.imr_multiaddr.s_addr	= ip->sin.sin_addr.s_addr,
+			.imr_ifindex		= ifindex,
+		};
+
+		sk = sock4->sock->sk;
+		lock_sock(sk);
+		ret = ip_mc_leave_group(sk, &mreq);
+		release_sock(sk);
+#if IS_ENABLED(CONFIG_IPV6)
+	} else {
+		struct vxlan_sock *sock6 = rtnl_dereference(vxlan->vn6_sock);
+
+		sk = sock6->sock->sk;
+		lock_sock(sk);
+		ret = ipv6_stub->ipv6_sock_mc_drop(sk, ifindex,
+						   &ip->sin6.sin6_addr);
+		release_sock(sk);
+#endif
+	}
+
+	return ret;
+}
+
+static bool vxlan_group_used_match(union vxlan_addr *ip, int ifindex,
+				   union vxlan_addr *rip, int rifindex)
+{
+	if (!vxlan_addr_multicast(rip))
+		return false;
+
+	if (!vxlan_addr_equal(rip, ip))
+		return false;
+
+	if (rifindex != ifindex)
+		return false;
+
+	return true;
+}
+
+static bool vxlan_group_used_by_vnifilter(struct vxlan_dev *vxlan,
+					  union vxlan_addr *ip, int ifindex)
+{
+	struct vxlan_vni_group *vg = rtnl_dereference(vxlan->vnigrp);
+	struct vxlan_vni_node *v, *tmp;
+
+	if (vxlan_group_used_match(ip, ifindex,
+				   &vxlan->default_dst.remote_ip,
+				   vxlan->default_dst.remote_ifindex))
+		return true;
+
+	list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) {
+		if (!vxlan_addr_multicast(&v->remote_ip))
+			continue;
+
+		if (vxlan_group_used_match(ip, ifindex,
+					   &v->remote_ip,
+					   vxlan->default_dst.remote_ifindex))
+			return true;
+	}
+
+	return false;
+}
+
+/* See if multicast group is already in use by other ID */
+bool vxlan_group_used(struct vxlan_net *vn, struct vxlan_dev *dev,
+		      __be32 vni, union vxlan_addr *rip, int rifindex)
+{
+	union vxlan_addr *ip = (rip ? : &dev->default_dst.remote_ip);
+	int ifindex = (rifindex ? : dev->default_dst.remote_ifindex);
+	struct vxlan_dev *vxlan;
+	struct vxlan_sock *sock4;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct vxlan_sock *sock6;
+#endif
+	unsigned short family = dev->default_dst.remote_ip.sa.sa_family;
+
+	sock4 = rtnl_dereference(dev->vn4_sock);
+
+	/* The vxlan_sock is only used by dev, leaving group has
+	 * no effect on other vxlan devices.
+	 */
+	if (family == AF_INET && sock4 && refcount_read(&sock4->refcnt) == 1)
+		return false;
+
+#if IS_ENABLED(CONFIG_IPV6)
+	sock6 = rtnl_dereference(dev->vn6_sock);
+	if (family == AF_INET6 && sock6 && refcount_read(&sock6->refcnt) == 1)
+		return false;
+#endif
+
+	list_for_each_entry(vxlan, &vn->vxlan_list, next) {
+		if (!netif_running(vxlan->dev) || vxlan == dev)
+			continue;
+
+		if (family == AF_INET &&
+		    rtnl_dereference(vxlan->vn4_sock) != sock4)
+			continue;
+#if IS_ENABLED(CONFIG_IPV6)
+		if (family == AF_INET6 &&
+		    rtnl_dereference(vxlan->vn6_sock) != sock6)
+			continue;
+#endif
+		if (vxlan->cfg.flags & VXLAN_F_VNIFILTER) {
+			if (!vxlan_group_used_by_vnifilter(vxlan, ip, ifindex))
+				continue;
+		} else {
+			if (!vxlan_group_used_match(ip, ifindex,
+						    &vxlan->default_dst.remote_ip,
+						    vxlan->default_dst.remote_ifindex))
+				continue;
+		}
+
+		return true;
+	}
+
+	return false;
+}
+
+static int vxlan_multicast_join_vnigrp(struct vxlan_dev *vxlan)
+{
+	struct vxlan_vni_group *vg = rtnl_dereference(vxlan->vnigrp);
+	struct vxlan_vni_node *v, *tmp, *vgood = NULL;
+	int ret = 0;
+
+	list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) {
+		if (!vxlan_addr_multicast(&v->remote_ip))
+			continue;
+		/* skip if address is same as default address */
+		if (vxlan_addr_equal(&v->remote_ip,
+				     &vxlan->default_dst.remote_ip))
+			continue;
+		ret = vxlan_igmp_join(vxlan, &v->remote_ip, 0);
+		if (ret == -EADDRINUSE)
+			ret = 0;
+		if (ret)
+			goto out;
+		vgood = v;
+	}
+out:
+	if (ret) {
+		list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) {
+			if (!vxlan_addr_multicast(&v->remote_ip))
+				continue;
+			if (vxlan_addr_equal(&v->remote_ip,
+					     &vxlan->default_dst.remote_ip))
+				continue;
+			vxlan_igmp_leave(vxlan, &v->remote_ip, 0);
+			if (v == vgood)
+				break;
+		}
+	}
+
+	return ret;
+}
+
+static int vxlan_multicast_leave_vnigrp(struct vxlan_dev *vxlan)
+{
+	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
+	struct vxlan_vni_group *vg = rtnl_dereference(vxlan->vnigrp);
+	struct vxlan_vni_node *v, *tmp;
+	int last_err = 0, ret;
+
+	list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) {
+		if (vxlan_addr_multicast(&v->remote_ip) &&
+		    !vxlan_group_used(vn, vxlan, v->vni, &v->remote_ip,
+				      0)) {
+			ret = vxlan_igmp_leave(vxlan, &v->remote_ip, 0);
+			if (ret)
+				last_err = ret;
+		}
+	}
+
+	return last_err;
+}
+
+int vxlan_multicast_join(struct vxlan_dev *vxlan)
+{
+	int ret = 0;
+
+	if (vxlan_addr_multicast(&vxlan->default_dst.remote_ip)) {
+		ret = vxlan_igmp_join(vxlan, &vxlan->default_dst.remote_ip,
+				      vxlan->default_dst.remote_ifindex);
+		if (ret == -EADDRINUSE)
+			ret = 0;
+		if (ret)
+			return ret;
+	}
+
+	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER)
+		return vxlan_multicast_join_vnigrp(vxlan);
+
+	return 0;
+}
+
+int vxlan_multicast_leave(struct vxlan_dev *vxlan)
+{
+	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
+	int ret = 0;
+
+	if (vxlan_addr_multicast(&vxlan->default_dst.remote_ip) &&
+	    !vxlan_group_used(vn, vxlan, 0, NULL, 0)) {
+		ret = vxlan_igmp_leave(vxlan, &vxlan->default_dst.remote_ip,
+				       vxlan->default_dst.remote_ifindex);
+		if (ret)
+			return ret;
+	}
+
+	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER)
+		return vxlan_multicast_leave_vnigrp(vxlan);
+
+	return 0;
+}