netfilter: conntrack: simplify init/uninit of L4 protocol trackers

modify registration and deregistration of layer-4 protocol trackers to
facilitate inclusion of new elements into the current list of builtin
protocols. Both builtin (TCP, UDP, ICMP) and non-builtin (DCCP, GRE, SCTP,
UDPlite) layer-4 protocol trackers usually register/deregister themselves
using consecutive calls to nf_ct_l4proto_{,pernet}_{,un}register(...).
This sequence is interrupted and rolled back in case of error; in order to
simplify addition of builtin protocols, the input of the above functions
has been modified to allow registering/unregistering multiple protocols.

Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 24 insertions, 54 deletions

diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
index 963ee3848675..500be28ff563 100644
--- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
@@ -336,47 +336,35 @@ static struct nf_sockopt_ops so_getorigdst6 = {
 	.owner		= THIS_MODULE,
 };
 
+static struct nf_conntrack_l4proto *builtin_l4proto6[] = {
+	&nf_conntrack_l4proto_tcp6,
+	&nf_conntrack_l4proto_udp6,
+	&nf_conntrack_l4proto_icmpv6,
+};
+
 static int ipv6_net_init(struct net *net)
 {
 	int ret = 0;
 
-	ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_tcp6);
-	if (ret < 0) {
-		pr_err("nf_conntrack_tcp6: pernet registration failed\n");
-		goto out;
-	}
-	ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_udp6);
-	if (ret < 0) {
-		pr_err("nf_conntrack_udp6: pernet registration failed\n");
-		goto cleanup_tcp6;
-	}
-	ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_icmpv6);
-	if (ret < 0) {
-		pr_err("nf_conntrack_icmp6: pernet registration failed\n");
-		goto cleanup_udp6;
-	}
+	ret = nf_ct_l4proto_pernet_register(net, builtin_l4proto6,
+					    ARRAY_SIZE(builtin_l4proto6));
+	if (ret < 0)
+		return ret;
+
 	ret = nf_ct_l3proto_pernet_register(net, &nf_conntrack_l3proto_ipv6);
 	if (ret < 0) {
 		pr_err("nf_conntrack_ipv6: pernet registration failed.\n");
-		goto cleanup_icmpv6;
+		nf_ct_l4proto_pernet_unregister(net, builtin_l4proto6,
+						ARRAY_SIZE(builtin_l4proto6));
 	}
-	return 0;
- cleanup_icmpv6:
-	nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_icmpv6);
- cleanup_udp6:
-	nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_udp6);
- cleanup_tcp6:
-	nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_tcp6);
- out:
 	return ret;
 }
 
 static void ipv6_net_exit(struct net *net)
 {
 	nf_ct_l3proto_pernet_unregister(net, &nf_conntrack_l3proto_ipv6);
-	nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_icmpv6);
-	nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_udp6);
-	nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_tcp6);
+	nf_ct_l4proto_pernet_unregister(net, builtin_l4proto6,
+					ARRAY_SIZE(builtin_l4proto6));
 }
 
 static struct pernet_operations ipv6_net_ops = {
@@ -409,37 +397,20 @@ static int __init nf_conntrack_l3proto_ipv6_init(void)
 		goto cleanup_pernet;
 	}
 
-	ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_tcp6);
-	if (ret < 0) {
-		pr_err("nf_conntrack_ipv6: can't register tcp6 proto.\n");
+	ret = nf_ct_l4proto_register(builtin_l4proto6,
+				     ARRAY_SIZE(builtin_l4proto6));
+	if (ret < 0)
 		goto cleanup_hooks;
-	}
-
-	ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_udp6);
-	if (ret < 0) {
-		pr_err("nf_conntrack_ipv6: can't register udp6 proto.\n");
-		goto cleanup_tcp6;
-	}
-
-	ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_icmpv6);
-	if (ret < 0) {
-		pr_err("nf_conntrack_ipv6: can't register icmpv6 proto.\n");
-		goto cleanup_udp6;
-	}
 
 	ret = nf_ct_l3proto_register(&nf_conntrack_l3proto_ipv6);
 	if (ret < 0) {
 		pr_err("nf_conntrack_ipv6: can't register ipv6 proto.\n");
-		goto cleanup_icmpv6;
+		goto cleanup_l4proto;
 	}
 	return ret;
-
- cleanup_icmpv6:
-	nf_ct_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
- cleanup_udp6:
-	nf_ct_l4proto_unregister(&nf_conntrack_l4proto_udp6);
- cleanup_tcp6:
-	nf_ct_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
+cleanup_l4proto:
+	nf_ct_l4proto_unregister(builtin_l4proto6,
+				 ARRAY_SIZE(builtin_l4proto6));
  cleanup_hooks:
 	nf_unregister_hooks(ipv6_conntrack_ops, ARRAY_SIZE(ipv6_conntrack_ops));
  cleanup_pernet:
@@ -453,9 +424,8 @@ static void __exit nf_conntrack_l3proto_ipv6_fini(void)
 {
 	synchronize_net();
 	nf_ct_l3proto_unregister(&nf_conntrack_l3proto_ipv6);
-	nf_ct_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
-	nf_ct_l4proto_unregister(&nf_conntrack_l4proto_udp6);
-	nf_ct_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
+	nf_ct_l4proto_unregister(builtin_l4proto6,
+				 ARRAY_SIZE(builtin_l4proto6));
 	nf_unregister_hooks(ipv6_conntrack_ops, ARRAY_SIZE(ipv6_conntrack_ops));
 	unregister_pernet_subsys(&ipv6_net_ops);
 	nf_unregister_sockopt(&so_getorigdst6);