1 files changed, 74 insertions, 37 deletions

diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index bf3117771822..7e3e669baac4 100644
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -31,14 +31,7 @@
 #include "l2tp_core.h"
 
 
-static struct genl_family l2tp_nl_family = {
-	.id		= GENL_ID_GENERATE,
-	.name		= L2TP_GENL_NAME,
-	.version	= L2TP_GENL_VERSION,
-	.hdrsize	= 0,
-	.maxattr	= L2TP_ATTR_MAX,
-	.netnsok	= true,
-};
+static struct genl_family l2tp_nl_family;
 
 static const struct genl_multicast_group l2tp_multicast_group[] = {
 	{
@@ -55,7 +48,8 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq,
 /* Accessed under genl lock */
 static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
 
-static struct l2tp_session *l2tp_nl_session_find(struct genl_info *info)
+static struct l2tp_session *l2tp_nl_session_get(struct genl_info *info,
+						bool do_ref)
 {
 	u32 tunnel_id;
 	u32 session_id;
@@ -66,14 +60,15 @@ static struct l2tp_session *l2tp_nl_session_find(struct genl_info *info)
 
 	if (info->attrs[L2TP_ATTR_IFNAME]) {
 		ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
-		session = l2tp_session_find_by_ifname(net, ifname);
+		session = l2tp_session_get_by_ifname(net, ifname, do_ref);
 	} else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
 		   (info->attrs[L2TP_ATTR_CONN_ID])) {
 		tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 		session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
 		tunnel = l2tp_tunnel_find(net, tunnel_id);
 		if (tunnel)
-			session = l2tp_session_find(net, tunnel, session_id);
+			session = l2tp_session_get(net, tunnel, session_id,
+						   do_ref);
 	}
 
 	return session;
@@ -227,14 +222,14 @@ static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info
 			cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
 		if (info->attrs[L2TP_ATTR_UDP_DPORT])
 			cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
-		if (info->attrs[L2TP_ATTR_UDP_CSUM])
-			cfg.use_udp_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_CSUM]);
+		cfg.use_udp_checksums = nla_get_flag(
+			info->attrs[L2TP_ATTR_UDP_CSUM]);
 
 #if IS_ENABLED(CONFIG_IPV6)
-		if (info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX])
-			cfg.udp6_zero_tx_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
-		if (info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX])
-			cfg.udp6_zero_rx_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
+		cfg.udp6_zero_tx_checksums = nla_get_flag(
+			info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
+		cfg.udp6_zero_rx_checksums = nla_get_flag(
+			info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
 #endif
 	}
 
@@ -386,9 +381,24 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int fla
 
 	switch (tunnel->encap) {
 	case L2TP_ENCAPTYPE_UDP:
+		switch (sk->sk_family) {
+		case AF_INET:
+			if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
+				goto nla_put_failure;
+			break;
+#if IS_ENABLED(CONFIG_IPV6)
+		case AF_INET6:
+			if (udp_get_no_check6_tx(sk) &&
+			    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
+				goto nla_put_failure;
+			if (udp_get_no_check6_rx(sk) &&
+			    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
+				goto nla_put_failure;
+			break;
+#endif
+		}
 		if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
-		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)) ||
-		    nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
+		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
 			goto nla_put_failure;
 		/* NOBREAK */
 	case L2TP_ENCAPTYPE_IP:
@@ -634,10 +644,12 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf
 			session_id, peer_session_id, &cfg);
 
 	if (ret >= 0) {
-		session = l2tp_session_find(net, tunnel, session_id);
-		if (session)
+		session = l2tp_session_get(net, tunnel, session_id, false);
+		if (session) {
 			ret = l2tp_session_notify(&l2tp_nl_family, info, session,
 						  L2TP_CMD_SESSION_CREATE);
+			l2tp_session_dec_refcount(session);
+		}
 	}
 
 out:
@@ -650,7 +662,7 @@ static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *inf
 	struct l2tp_session *session;
 	u16 pw_type;
 
-	session = l2tp_nl_session_find(info);
+	session = l2tp_nl_session_get(info, true);
 	if (session == NULL) {
 		ret = -ENODEV;
 		goto out;
@@ -664,6 +676,10 @@ static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *inf
 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
 			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
 
+	if (session->deref)
+		session->deref(session);
+	l2tp_session_dec_refcount(session);
+
 out:
 	return ret;
 }
@@ -673,7 +689,7 @@ static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *inf
 	int ret = 0;
 	struct l2tp_session *session;
 
-	session = l2tp_nl_session_find(info);
+	session = l2tp_nl_session_get(info, false);
 	if (session == NULL) {
 		ret = -ENODEV;
 		goto out;
@@ -708,6 +724,8 @@ static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *inf
 	ret = l2tp_session_notify(&l2tp_nl_family, info,
 				  session, L2TP_CMD_SESSION_MODIFY);
 
+	l2tp_session_dec_refcount(session);
+
 out:
 	return ret;
 }
@@ -803,29 +821,34 @@ static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
 	struct sk_buff *msg;
 	int ret;
 
-	session = l2tp_nl_session_find(info);
+	session = l2tp_nl_session_get(info, false);
 	if (session == NULL) {
 		ret = -ENODEV;
-		goto out;
+		goto err;
 	}
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 	if (!msg) {
 		ret = -ENOMEM;
-		goto out;
+		goto err_ref;
 	}
 
 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
 				   0, session, L2TP_CMD_SESSION_GET);
 	if (ret < 0)
-		goto err_out;
+		goto err_ref_msg;
 
-	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
+	ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
 
-err_out:
-	nlmsg_free(msg);
+	l2tp_session_dec_refcount(session);
 
-out:
+	return ret;
+
+err_ref_msg:
+	nlmsg_free(msg);
+err_ref:
+	l2tp_session_dec_refcount(session);
+err:
 	return ret;
 }
 
@@ -844,7 +867,7 @@ static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback
 				goto out;
 		}
 
-		session = l2tp_session_find_nth(tunnel, si);
+		session = l2tp_session_get_nth(tunnel, si, false);
 		if (session == NULL) {
 			ti++;
 			tunnel = NULL;
@@ -854,8 +877,11 @@ static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback
 
 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
-					 session, L2TP_CMD_SESSION_GET) < 0)
+					 session, L2TP_CMD_SESSION_GET) < 0) {
+			l2tp_session_dec_refcount(session);
 			break;
+		}
+		l2tp_session_dec_refcount(session);
 
 		si++;
 	}
@@ -977,6 +1003,19 @@ static const struct genl_ops l2tp_nl_ops[] = {
 	},
 };
 
+static struct genl_family l2tp_nl_family __ro_after_init = {
+	.name		= L2TP_GENL_NAME,
+	.version	= L2TP_GENL_VERSION,
+	.hdrsize	= 0,
+	.maxattr	= L2TP_ATTR_MAX,
+	.netnsok	= true,
+	.module		= THIS_MODULE,
+	.ops		= l2tp_nl_ops,
+	.n_ops		= ARRAY_SIZE(l2tp_nl_ops),
+	.mcgrps		= l2tp_multicast_group,
+	.n_mcgrps	= ARRAY_SIZE(l2tp_multicast_group),
+};
+
 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
 {
 	int ret;
@@ -1010,12 +1049,10 @@ void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
 }
 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
 
-static int l2tp_nl_init(void)
+static int __init l2tp_nl_init(void)
 {
 	pr_info("L2TP netlink interface\n");
-	return genl_register_family_with_ops_groups(&l2tp_nl_family,
-						    l2tp_nl_ops,
-						    l2tp_multicast_group);
+	return genl_register_family(&l2tp_nl_family);
 }
 
 static void l2tp_nl_cleanup(void)