#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 <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_core.h>
-struct nf_conntrack_l4proto **nf_ct_protos[PF_MAX] __read_mostly;
+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_table *path,
+ struct ctl_table *table, unsigned int *users)
+{
+ if (*header == NULL) {
+ *header = nf_register_sysctl_table(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;
+ nf_unregister_sysctl_table(*header, table);
+ *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 nf_ct_protos[l3proto][l4proto];
+ 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 *p;
- preempt_disable();
+ rcu_read_lock();
p = __nf_ct_l4proto_find(l3proto, l4proto);
if (!try_module_get(p->me))
p = &nf_conntrack_l4proto_generic;
- preempt_enable();
+ 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;
- preempt_disable();
+ rcu_read_lock();
p = __nf_ct_l3proto_find(l3proto);
if (!try_module_get(p->me))
p = &nf_conntrack_l3proto_generic;
- preempt_enable();
+ 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)
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;
- preempt_disable();
+ /* rcu_read_lock not necessary since the caller holds a reference */
p = __nf_ct_l3proto_find(l3proto);
- preempt_enable();
-
module_put(p->me);
}
+EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
static int kill_l3proto(struct nf_conn *i, void *data)
{
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) {
- ret = -EBUSY;
- goto out;
- }
+ if (proto->l3proto >= AF_MAX)
+ return -EBUSY;
- write_lock_bh(&nf_conntrack_lock);
+ mutex_lock(&nf_ct_proto_mutex);
if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
ret = -EBUSY;
goto out_unlock;
}
- nf_ct_l3protos[proto->l3proto] = proto;
+
+ ret = nf_ct_l3proto_register_sysctl(proto);
+ if (ret < 0)
+ goto out_unlock;
+
+ rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
out_unlock:
- write_unlock_bh(&nf_conntrack_lock);
-out:
+ mutex_unlock(&nf_ct_proto_mutex);
return ret;
}
+EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register);
-int nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
+void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
{
- int ret = 0;
+ BUG_ON(proto->l3proto >= AF_MAX);
- if (proto->l3proto >= AF_MAX) {
- ret = -EBUSY;
- goto out;
- }
+ 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);
- write_lock_bh(&nf_conntrack_lock);
- if (nf_ct_l3protos[proto->l3proto] != proto) {
- write_unlock_bh(&nf_conntrack_lock);
- ret = -EBUSY;
- goto out;
- }
-
- nf_ct_l3protos[proto->l3proto] = &nf_conntrack_l3proto_generic;
- write_unlock_bh(&nf_conntrack_lock);
-
- /* Somebody could be still looking at the proto in bh. */
- synchronize_net();
+ synchronize_rcu();
/* Remove all contrack entries for this protocol */
nf_ct_iterate_cleanup(kill_l3proto, proto);
+}
+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:
- return ret;
+#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
{
int ret = 0;
- if (l4proto->l3proto >= PF_MAX) {
- ret = -EBUSY;
- goto out;
- }
+ if (l4proto->l3proto >= PF_MAX)
+ return -EBUSY;
-retry:
- write_lock_bh(&nf_conntrack_lock);
- if (nf_ct_protos[l4proto->l3proto]) {
- if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto]
- != &nf_conntrack_l4proto_generic) {
- ret = -EBUSY;
- goto out_unlock;
- }
- } else {
+ 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;
- write_unlock_bh(&nf_conntrack_lock);
-
- proto_array = (struct nf_conntrack_l4proto **)
- kmalloc(MAX_NF_CT_PROTO *
- sizeof(struct nf_conntrack_l4proto *),
- GFP_KERNEL);
+ proto_array = kmalloc(MAX_NF_CT_PROTO *
+ sizeof(struct nf_conntrack_l4proto *),
+ GFP_KERNEL);
if (proto_array == NULL) {
ret = -ENOMEM;
- goto out;
+ goto out_unlock;
}
+
for (i = 0; i < MAX_NF_CT_PROTO; i++)
proto_array[i] = &nf_conntrack_l4proto_generic;
-
- write_lock_bh(&nf_conntrack_lock);
- if (nf_ct_protos[l4proto->l3proto]) {
- /* bad timing, but no problem */
- write_unlock_bh(&nf_conntrack_lock);
- kfree(proto_array);
- } else {
- nf_ct_protos[l4proto->l3proto] = proto_array;
- write_unlock_bh(&nf_conntrack_lock);
- }
-
- /*
- * Just once because array is never freed until unloading
- * nf_conntrack.ko
- */
- goto retry;
+ 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;
}
- nf_ct_protos[l4proto->l3proto][l4proto->l4proto] = l4proto;
+ 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:
- write_unlock_bh(&nf_conntrack_lock);
-out:
+ mutex_unlock(&nf_ct_proto_mutex);
return ret;
}
+EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register);
-int nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
+void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
{
- int ret = 0;
+ BUG_ON(l4proto->l3proto >= PF_MAX);
- if (l4proto->l3proto >= PF_MAX) {
- ret = -EBUSY;
- goto out;
- }
+ 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);
- write_lock_bh(&nf_conntrack_lock);
- if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto]
- != l4proto) {
- write_unlock_bh(&nf_conntrack_lock);
- ret = -EBUSY;
- goto out;
- }
- nf_ct_protos[l4proto->l3proto][l4proto->l4proto]
- = &nf_conntrack_l4proto_generic;
- write_unlock_bh(&nf_conntrack_lock);
-
- /* Somebody could be still looking at the proto in bh. */
- synchronize_net();
+ synchronize_rcu();
/* Remove all contrack entries for this protocol */
nf_ct_iterate_cleanup(kill_l4proto, l4proto);
+}
+EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);
-out:
- return ret;
+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]);
}