1 files changed, 370 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c
new file mode 100644
index 0000000..592d733
--- /dev/null
+++ b/net/netfilter/nf_conntrack_proto.c
@@ -0,0 +1,370 @@
+/* L3/L4 protocol support for nf_conntrack. */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/netfilter.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/skbuff.h>
+#include <linux/vmalloc.h>
+#include <linux/stddef.h>
+#include <linux/err.h>
+#include <linux/percpu.h>
+#include <linux/moduleparam.h>
+#include <linux/notifier.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/rtnetlink.h>
+
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_l3proto.h>
+#include <net/netfilter/nf_conntrack_l4proto.h>
+#include <net/netfilter/nf_conntrack_core.h>
+
+static struct nf_conntrack_l4proto **nf_ct_protos[PF_MAX] __read_mostly;
+struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX] __read_mostly;
+EXPORT_SYMBOL_GPL(nf_ct_l3protos);
+
+static DEFINE_MUTEX(nf_ct_proto_mutex);
+
+#ifdef CONFIG_SYSCTL
+static int
+nf_ct_register_sysctl(struct ctl_table_header **header, struct ctl_path *path,
+		      struct ctl_table *table, unsigned int *users)
+{
+	if (*header == NULL) {
+		*header = register_sysctl_paths(path, table);
+		if (*header == NULL)
+			return -ENOMEM;
+	}
+	if (users != NULL)
+		(*users)++;
+	return 0;
+}
+
+static void
+nf_ct_unregister_sysctl(struct ctl_table_header **header,
+			struct ctl_table *table, unsigned int *users)
+{
+	if (users != NULL && --*users > 0)
+		return;
+
+	unregister_sysctl_table(*header);
+	*header = NULL;
+}
+#endif
+
+struct nf_conntrack_l4proto *
+__nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
+{
+	if (unlikely(l3proto >= AF_MAX || nf_ct_protos[l3proto] == NULL))
+		return &nf_conntrack_l4proto_generic;
+
+	return rcu_dereference(nf_ct_protos[l3proto][l4proto]);
+}
+EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find);
+
+/* this is guaranteed to always return a valid protocol helper, since
+ * it falls back to generic_protocol */
+struct nf_conntrack_l4proto *
+nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t l4proto)
+{
+	struct nf_conntrack_l4proto *p;
+
+	rcu_read_lock();
+	p = __nf_ct_l4proto_find(l3proto, l4proto);
+	if (!try_module_get(p->me))
+		p = &nf_conntrack_l4proto_generic;
+	rcu_read_unlock();
+
+	return p;
+}
+EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get);
+
+void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p)
+{
+	module_put(p->me);
+}
+EXPORT_SYMBOL_GPL(nf_ct_l4proto_put);
+
+struct nf_conntrack_l3proto *
+nf_ct_l3proto_find_get(u_int16_t l3proto)
+{
+	struct nf_conntrack_l3proto *p;
+
+	rcu_read_lock();
+	p = __nf_ct_l3proto_find(l3proto);
+	if (!try_module_get(p->me))
+		p = &nf_conntrack_l3proto_generic;
+	rcu_read_unlock();
+
+	return p;
+}
+EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get);
+
+void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p)
+{
+	module_put(p->me);
+}
+EXPORT_SYMBOL_GPL(nf_ct_l3proto_put);
+
+int
+nf_ct_l3proto_try_module_get(unsigned short l3proto)
+{
+	int ret;
+	struct nf_conntrack_l3proto *p;
+
+retry:	p = nf_ct_l3proto_find_get(l3proto);
+	if (p == &nf_conntrack_l3proto_generic) {
+		ret = request_module("nf_conntrack-%d", l3proto);
+		if (!ret)
+			goto retry;
+
+		return -EPROTOTYPE;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get);
+
+void nf_ct_l3proto_module_put(unsigned short l3proto)
+{
+	struct nf_conntrack_l3proto *p;
+
+	/* rcu_read_lock not necessary since the caller holds a reference */
+	p = __nf_ct_l3proto_find(l3proto);
+	module_put(p->me);
+}
+EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
+
+static int kill_l3proto(struct nf_conn *i, void *data)
+{
+	return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto;
+}
+
+static int kill_l4proto(struct nf_conn *i, void *data)
+{
+	struct nf_conntrack_l4proto *l4proto;
+	l4proto = (struct nf_conntrack_l4proto *)data;
+	return nf_ct_protonum(i) == l4proto->l4proto &&
+	       nf_ct_l3num(i) == l4proto->l3proto;
+}
+
+static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
+{
+	int err = 0;
+
+#ifdef CONFIG_SYSCTL
+	if (l3proto->ctl_table != NULL) {
+		err = nf_ct_register_sysctl(&l3proto->ctl_table_header,
+					    l3proto->ctl_table_path,
+					    l3proto->ctl_table, NULL);
+	}
+#endif
+	return err;
+}
+
+static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto)
+{
+#ifdef CONFIG_SYSCTL
+	if (l3proto->ctl_table_header != NULL)
+		nf_ct_unregister_sysctl(&l3proto->ctl_table_header,
+					l3proto->ctl_table, NULL);
+#endif
+}
+
+int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
+{
+	int ret = 0;
+
+	if (proto->l3proto >= AF_MAX)
+		return -EBUSY;
+
+	mutex_lock(&nf_ct_proto_mutex);
+	if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
+		ret = -EBUSY;
+		goto out_unlock;
+	}
+
+	ret = nf_ct_l3proto_register_sysctl(proto);
+	if (ret < 0)
+		goto out_unlock;
+
+	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
+
+out_unlock:
+	mutex_unlock(&nf_ct_proto_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register);
+
+void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
+{
+	struct net *net;
+
+	BUG_ON(proto->l3proto >= AF_MAX);
+
+	mutex_lock(&nf_ct_proto_mutex);
+	BUG_ON(nf_ct_l3protos[proto->l3proto] != proto);
+	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
+			   &nf_conntrack_l3proto_generic);
+	nf_ct_l3proto_unregister_sysctl(proto);
+	mutex_unlock(&nf_ct_proto_mutex);
+
+	synchronize_rcu();
+
+	/* Remove all contrack entries for this protocol */
+	rtnl_lock();
+	for_each_net(net)
+		nf_ct_iterate_cleanup(net, kill_l3proto, proto);
+	rtnl_unlock();
+}
+EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);
+
+static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
+{
+	int err = 0;
+
+#ifdef CONFIG_SYSCTL
+	if (l4proto->ctl_table != NULL) {
+		err = nf_ct_register_sysctl(l4proto->ctl_table_header,
+					    nf_net_netfilter_sysctl_path,
+					    l4proto->ctl_table,
+					    l4proto->ctl_table_users);
+		if (err < 0)
+			goto out;
+	}
+#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
+	if (l4proto->ctl_compat_table != NULL) {
+		err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header,
+					    nf_net_ipv4_netfilter_sysctl_path,
+					    l4proto->ctl_compat_table, NULL);
+		if (err == 0)
+			goto out;
+		nf_ct_unregister_sysctl(l4proto->ctl_table_header,
+					l4proto->ctl_table,
+					l4proto->ctl_table_users);
+	}
+#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
+out:
+#endif /* CONFIG_SYSCTL */
+	return err;
+}
+
+static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
+{
+#ifdef CONFIG_SYSCTL
+	if (l4proto->ctl_table_header != NULL &&
+	    *l4proto->ctl_table_header != NULL)
+		nf_ct_unregister_sysctl(l4proto->ctl_table_header,
+					l4proto->ctl_table,
+					l4proto->ctl_table_users);
+#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
+	if (l4proto->ctl_compat_table_header != NULL)
+		nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header,
+					l4proto->ctl_compat_table, NULL);
+#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
+#endif /* CONFIG_SYSCTL */
+}
+
+/* FIXME: Allow NULL functions and sub in pointers to generic for
+   them. --RR */
+int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
+{
+	int ret = 0;
+
+	if (l4proto->l3proto >= PF_MAX)
+		return -EBUSY;
+
+	mutex_lock(&nf_ct_proto_mutex);
+	if (!nf_ct_protos[l4proto->l3proto]) {
+		/* l3proto may be loaded latter. */
+		struct nf_conntrack_l4proto **proto_array;
+		int i;
+
+		proto_array = kmalloc(MAX_NF_CT_PROTO *
+				      sizeof(struct nf_conntrack_l4proto *),
+				      GFP_KERNEL);
+		if (proto_array == NULL) {
+			ret = -ENOMEM;
+			goto out_unlock;
+		}
+
+		for (i = 0; i < MAX_NF_CT_PROTO; i++)
+			proto_array[i] = &nf_conntrack_l4proto_generic;
+		nf_ct_protos[l4proto->l3proto] = proto_array;
+	} else if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] !=
+					&nf_conntrack_l4proto_generic) {
+		ret = -EBUSY;
+		goto out_unlock;
+	}
+
+	ret = nf_ct_l4proto_register_sysctl(l4proto);
+	if (ret < 0)
+		goto out_unlock;
+
+	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
+			   l4proto);
+
+out_unlock:
+	mutex_unlock(&nf_ct_proto_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register);
+
+void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
+{
+	struct net *net;
+
+	BUG_ON(l4proto->l3proto >= PF_MAX);
+
+	mutex_lock(&nf_ct_proto_mutex);
+	BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto);
+	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
+			   &nf_conntrack_l4proto_generic);
+	nf_ct_l4proto_unregister_sysctl(l4proto);
+	mutex_unlock(&nf_ct_proto_mutex);
+
+	synchronize_rcu();
+
+	/* Remove all contrack entries for this protocol */
+	rtnl_lock();
+	for_each_net(net)
+		nf_ct_iterate_cleanup(net, kill_l4proto, l4proto);
+	rtnl_unlock();
+}
+EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);
+
+int nf_conntrack_proto_init(void)
+{
+	unsigned int i;
+	int err;
+
+	err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic);
+	if (err < 0)
+		return err;
+
+	for (i = 0; i < AF_MAX; i++)
+		rcu_assign_pointer(nf_ct_l3protos[i],
+				   &nf_conntrack_l3proto_generic);
+	return 0;
+}
+
+void nf_conntrack_proto_fini(void)
+{
+	unsigned int i;
+
+	nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic);
+
+	/* free l3proto protocol tables */
+	for (i = 0; i < PF_MAX; i++)
+		kfree(nf_ct_protos[i]);
+}