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, 23 insertions, 53 deletions

diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index 713c09a74b90..7130ed5dc1fa 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -336,47 +336,34 @@ MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET));
 MODULE_ALIAS("ip_conntrack");
 MODULE_LICENSE("GPL");
 
+static struct nf_conntrack_l4proto *builtin_l4proto4[] = {
+	&nf_conntrack_l4proto_tcp4,
+	&nf_conntrack_l4proto_udp4,
+	&nf_conntrack_l4proto_icmp,
+};
+
 static int ipv4_net_init(struct net *net)
 {
 	int ret = 0;
 
-	ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_tcp4);
-	if (ret < 0) {
-		pr_err("nf_conntrack_tcp4: pernet registration failed\n");
-		goto out_tcp;
-	}
-	ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_udp4);
-	if (ret < 0) {
-		pr_err("nf_conntrack_udp4: pernet registration failed\n");
-		goto out_udp;
-	}
-	ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_icmp);
-	if (ret < 0) {
-		pr_err("nf_conntrack_icmp4: pernet registration failed\n");
-		goto out_icmp;
-	}
+	ret = nf_ct_l4proto_pernet_register(net, builtin_l4proto4,
+					    ARRAY_SIZE(builtin_l4proto4));
+	if (ret < 0)
+		return ret;
 	ret = nf_ct_l3proto_pernet_register(net, &nf_conntrack_l3proto_ipv4);
 	if (ret < 0) {
 		pr_err("nf_conntrack_ipv4: pernet registration failed\n");
-		goto out_ipv4;
+		nf_ct_l4proto_pernet_unregister(net, builtin_l4proto4,
+						ARRAY_SIZE(builtin_l4proto4));
 	}
-	return 0;
-out_ipv4:
-	nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_icmp);
-out_icmp:
-	nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_udp4);
-out_udp:
-	nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_tcp4);
-out_tcp:
 	return ret;
 }
 
 static void ipv4_net_exit(struct net *net)
 {
 	nf_ct_l3proto_pernet_unregister(net, &nf_conntrack_l3proto_ipv4);
-	nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_icmp);
-	nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_udp4);
-	nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_tcp4);
+	nf_ct_l4proto_pernet_unregister(net, builtin_l4proto4,
+					ARRAY_SIZE(builtin_l4proto4));
 }
 
 static struct pernet_operations ipv4_net_ops = {
@@ -410,37 +397,21 @@ static int __init nf_conntrack_l3proto_ipv4_init(void)
 		goto cleanup_pernet;
 	}
 
-	ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_tcp4);
-	if (ret < 0) {
-		pr_err("nf_conntrack_ipv4: can't register tcp4 proto.\n");
+	ret = nf_ct_l4proto_register(builtin_l4proto4,
+				     ARRAY_SIZE(builtin_l4proto4));
+	if (ret < 0)
 		goto cleanup_hooks;
-	}
-
-	ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_udp4);
-	if (ret < 0) {
-		pr_err("nf_conntrack_ipv4: can't register udp4 proto.\n");
-		goto cleanup_tcp4;
-	}
-
-	ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_icmp);
-	if (ret < 0) {
-		pr_err("nf_conntrack_ipv4: can't register icmpv4 proto.\n");
-		goto cleanup_udp4;
-	}
 
 	ret = nf_ct_l3proto_register(&nf_conntrack_l3proto_ipv4);
 	if (ret < 0) {
 		pr_err("nf_conntrack_ipv4: can't register ipv4 proto.\n");
-		goto cleanup_icmpv4;
+		goto cleanup_l4proto;
 	}
 
 	return ret;
- cleanup_icmpv4:
-	nf_ct_l4proto_unregister(&nf_conntrack_l4proto_icmp);
- cleanup_udp4:
-	nf_ct_l4proto_unregister(&nf_conntrack_l4proto_udp4);
- cleanup_tcp4:
-	nf_ct_l4proto_unregister(&nf_conntrack_l4proto_tcp4);
+cleanup_l4proto:
+	nf_ct_l4proto_unregister(builtin_l4proto4,
+				 ARRAY_SIZE(builtin_l4proto4));
  cleanup_hooks:
 	nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
  cleanup_pernet:
@@ -454,9 +425,8 @@ static void __exit nf_conntrack_l3proto_ipv4_fini(void)
 {
 	synchronize_net();
 	nf_ct_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
-	nf_ct_l4proto_unregister(&nf_conntrack_l4proto_icmp);
-	nf_ct_l4proto_unregister(&nf_conntrack_l4proto_udp4);
-	nf_ct_l4proto_unregister(&nf_conntrack_l4proto_tcp4);
+	nf_ct_l4proto_unregister(builtin_l4proto4,
+				 ARRAY_SIZE(builtin_l4proto4));
 	nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
 	unregister_pernet_subsys(&ipv4_net_ops);
 	nf_unregister_sockopt(&so_getorigdst);