netfilter: nf_conntrack: generalize nf_ct_l4proto_net

This patch generalizes nf_ct_l4proto_net by splitting it into chunks and
moving the corresponding protocol part to where it really belongs to.

To clarify, note that we follow two different approaches to support per-net
depending if it's built-in or run-time loadable protocol tracker.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Gao feng <gaofeng@cn.fujitsu.com>

7 files changed, 41 insertions, 16 deletions

diff --git a/include/net/netfilter/nf_conntrack_l4proto.h b/include/net/netfilter/nf_conntrack_l4proto.h
index 08bb571b7abd..c3be4aef6bf7 100644
--- a/include/net/netfilter/nf_conntrack_l4proto.h
+++ b/include/net/netfilter/nf_conntrack_l4proto.h
@@ -99,6 +99,9 @@ struct nf_conntrack_l4proto {
         /* Init l4proto pernet data */
         int (*init_net)(struct net *net, u_int16_t proto);
 
+        /* Return the per-net protocol part. */
+        struct nf_proto_net *(*get_net_proto)(struct net *net);
+
         /* Protocol name */
         const char *name;
 
diff --git a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
index 9c2095c5571f..5241d997ab75 100644
--- a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
+++ b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
@@ -388,6 +388,11 @@ static int icmp_init_net(struct net *net, u_int16_t proto)
         return ret;
 }
 
+static struct nf_proto_net *icmp_get_net_proto(struct net *net)
+{
+        return &net->ct.nf_ct_proto.icmp.pn;
+}
+
 struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp __read_mostly =
 {
         .l3proto                = PF_INET,
@@ -418,4 +423,5 @@ struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp __read_mostly =
         },
 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
         .init_net               = icmp_init_net,
+        .get_net_proto          = icmp_get_net_proto,
 };
diff --git a/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c b/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c
index 9fc5cf5f3e8b..2d54b2061d68 100644
--- a/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c
@@ -358,6 +358,11 @@ static int icmpv6_init_net(struct net *net, u_int16_t proto)
         return icmpv6_kmemdup_sysctl_table(pn, in);
 }
 
+static struct nf_proto_net *icmpv6_get_net_proto(struct net *net)
+{
+        return &net->ct.nf_ct_proto.icmpv6.pn;
+}
+
 struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 __read_mostly =
 {
         .l3proto                = PF_INET6,
@@ -386,4 +391,5 @@ struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 __read_mostly =
         },
 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
         .init_net               = icmpv6_init_net,
+        .get_net_proto          = icmpv6_get_net_proto,
 };
diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c
index 21b850c4b3ab..0dc63854390f 100644
--- a/net/netfilter/nf_conntrack_proto.c
+++ b/net/netfilter/nf_conntrack_proto.c
@@ -303,22 +303,12 @@ EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);
 static struct nf_proto_net *nf_ct_l4proto_net(struct net *net,
                                               struct nf_conntrack_l4proto *l4proto)
 {
-        switch (l4proto->l4proto) {
-        case IPPROTO_TCP:
-                return (struct nf_proto_net *)&net->ct.nf_ct_proto.tcp;
-        case IPPROTO_UDP:
-                return (struct nf_proto_net *)&net->ct.nf_ct_proto.udp;
-        case IPPROTO_ICMP:
-                return (struct nf_proto_net *)&net->ct.nf_ct_proto.icmp;
-        case IPPROTO_ICMPV6:
-                return (struct nf_proto_net *)&net->ct.nf_ct_proto.icmpv6;
-        case 255: /* l4proto_generic */
-                return (struct nf_proto_net *)&net->ct.nf_ct_proto.generic;
-        default:
-                if (l4proto->net_id)
-                        return net_generic(net, *l4proto->net_id);
-                else
-                        return NULL;
+        if (l4proto->get_net_proto) {
+                /* statically built-in protocols use static per-net */
+                return l4proto->get_net_proto(net);
+        } else if (l4proto->net_id) {
+                /* ... and loadable protocols use dynamic per-net */
+                return net_generic(net, *l4proto->net_id);
         }
         return NULL;
 }
diff --git a/net/netfilter/nf_conntrack_proto_generic.c b/net/netfilter/nf_conntrack_proto_generic.c
index 7c11c5444194..d25f29377648 100644
--- a/net/netfilter/nf_conntrack_proto_generic.c
+++ b/net/netfilter/nf_conntrack_proto_generic.c
@@ -186,6 +186,11 @@ static int generic_init_net(struct net *net, u_int16_t proto)
         return ret;
 }
 
+static struct nf_proto_net *generic_get_net_proto(struct net *net)
+{
+        return &net->ct.nf_ct_proto.generic.pn;
+}
+
 struct nf_conntrack_l4proto nf_conntrack_l4proto_generic __read_mostly =
 {
         .l3proto                = PF_UNSPEC,
@@ -207,4 +212,5 @@ struct nf_conntrack_l4proto nf_conntrack_l4proto_generic __read_mostly =
         },
 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
         .init_net               = generic_init_net,
+        .get_net_proto          = generic_get_net_proto,
 };
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index 44f0da830156..07e56ea2e9bf 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -1623,6 +1623,11 @@ static int tcp_init_net(struct net *net, u_int16_t proto)
         return ret;
 }
 
+static struct nf_proto_net *tcp_get_net_proto(struct net *net)
+{
+        return &net->ct.nf_ct_proto.tcp.pn;
+}
+
 struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp4 __read_mostly =
 {
         .l3proto                = PF_INET,
@@ -1656,6 +1661,7 @@ struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp4 __read_mostly =
         },
 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
         .init_net               = tcp_init_net,
+        .get_net_proto          = tcp_get_net_proto,
 };
 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp4);
 
@@ -1692,5 +1698,6 @@ struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp6 __read_mostly =
         },
 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
         .init_net               = tcp_init_net,
+        .get_net_proto          = tcp_get_net_proto,
 };
 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp6);
diff --git a/net/netfilter/nf_conntrack_proto_udp.c b/net/netfilter/nf_conntrack_proto_udp.c
index e7e0434c3056..59623cc56e8d 100644
--- a/net/netfilter/nf_conntrack_proto_udp.c
+++ b/net/netfilter/nf_conntrack_proto_udp.c
@@ -297,6 +297,11 @@ static int udp_init_net(struct net *net, u_int16_t proto)
         return ret;
 }
 
+static struct nf_proto_net *udp_get_net_proto(struct net *net)
+{
+        return &net->ct.nf_ct_proto.udp.pn;
+}
+
 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 __read_mostly =
 {
         .l3proto                = PF_INET,
@@ -325,6 +330,7 @@ struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 __read_mostly =
         },
 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
         .init_net               = udp_init_net,
+        .get_net_proto          = udp_get_net_proto,
 };
 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4);
 
@@ -356,5 +362,6 @@ struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 __read_mostly =
         },
 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
         .init_net               = udp_init_net,
+        .get_net_proto          = udp_get_net_proto,
 };
 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6);