From: Liping Zhang <zlpnob...@gmail.com>
First, we should make the global nfnl_cthelper_list become per-net,
so different netns's user cthelpers will be linked to the different
global lists.
Second, when we do the netns cleanup work, we may invoke the
nfnl_cthelper_net_exit and nf_conntrack_helper_put in different orders,
so we should free the cthelper only when the refcnt is decreased to 0,
this is similar to nfnetlink_cttimeout.
Signed-off-by: Liping Zhang <zlpnob...@gmail.com>
---
include/net/netfilter/nf_conntrack_helper.h | 10 +++++
include/net/netns/conntrack.h | 3 ++
net/netfilter/nf_conntrack_helper.c | 2 +-
net/netfilter/nfnetlink_cthelper.c | 68 ++++++++++++++++++++---------
4 files changed, 61 insertions(+), 22 deletions(-)
diff --git a/include/net/netfilter/nf_conntrack_helper.h
b/include/net/netfilter/nf_conntrack_helper.h
index 7ac67c4..a63451f 100644
--- a/include/net/netfilter/nf_conntrack_helper.h
+++ b/include/net/netfilter/nf_conntrack_helper.h
@@ -82,6 +82,16 @@ static inline struct net *nf_ct_helper_net(struct
nf_conntrack_helper *helper)
return read_pnet(&helper->net);
}
+static inline void nf_ct_helper_put(struct nf_conntrack_helper *helper)
+{
+ if (refcount_dec_and_test(&helper->refcnt)) {
+ if (helper->flags & NF_CT_HELPER_F_USERSPACE) {
+ kfree(helper->expect_policy);
+ kfree(helper);
+ }
+ }
+}
+
struct nf_conntrack_helper *__nf_conntrack_helper_find(struct net *net,
const char *name,
u16 l3num, u8 protonum);
diff --git a/include/net/netns/conntrack.h b/include/net/netns/conntrack.h
index 244b794..8b1d2f9 100644
--- a/include/net/netns/conntrack.h
+++ b/include/net/netns/conntrack.h
@@ -111,6 +111,9 @@ struct netns_ct {
int sysctl_tstamp;
int sysctl_checksum;
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK_HELPER)
+ struct list_head nfnl_cthelper_list;
+#endif
unsigned int nf_ct_helper_count;
struct ct_pcpu __percpu *pcpu_lists;
diff --git a/net/netfilter/nf_conntrack_helper.c
b/net/netfilter/nf_conntrack_helper.c
index 3f3eeb9..248310d 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -201,8 +201,8 @@ EXPORT_SYMBOL_GPL(nf_conntrack_helper_try_module_get);
void nf_conntrack_helper_put(struct nf_conntrack_helper *helper)
{
- refcount_dec(&helper->refcnt);
module_put(helper->me);
+ nf_ct_helper_put(helper);
}
EXPORT_SYMBOL_GPL(nf_conntrack_helper_put);
diff --git a/net/netfilter/nfnetlink_cthelper.c
b/net/netfilter/nfnetlink_cthelper.c
index 90603b1..5c4a45a 100644
--- a/net/netfilter/nfnetlink_cthelper.c
+++ b/net/netfilter/nfnetlink_cthelper.c
@@ -33,12 +33,10 @@ MODULE_AUTHOR("Pablo Neira Ayuso <pa...@netfilter.org>");
MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers");
struct nfnl_cthelper {
- struct list_head list;
struct nf_conntrack_helper helper;
+ struct list_head list;
};
-static LIST_HEAD(nfnl_cthelper_list);
-
static int
nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff,
struct nf_conn *ct, enum ip_conntrack_info ctinfo)
@@ -214,7 +212,8 @@ nfnl_cthelper_parse_expect_policy(struct
nf_conntrack_helper *helper,
static int
nfnl_cthelper_create(const struct nlattr * const tb[],
- struct nf_conntrack_tuple *tuple)
+ struct nf_conntrack_tuple *tuple,
+ struct net *net)
{
struct nf_conntrack_helper *helper;
struct nfnl_cthelper *nfcth;
@@ -265,11 +264,11 @@ nfnl_cthelper_create(const struct nlattr * const tb[],
}
}
- ret = nf_conntrack_helper_register(&init_net, helper);
+ ret = nf_conntrack_helper_register(net, helper);
if (ret < 0)
goto err2;
- list_add_tail(&nfcth->list, &nfnl_cthelper_list);
+ list_add_tail(&nfcth->list, &net->ct.nfnl_cthelper_list);
return 0;
err2:
kfree(helper->expect_policy);
@@ -415,7 +414,7 @@ static int nfnl_cthelper_new(struct net *net, struct sock
*nfnl,
if (ret < 0)
return ret;
- list_for_each_entry(nlcth, &nfnl_cthelper_list, list) {
+ list_for_each_entry(nlcth, &net->ct.nfnl_cthelper_list, list) {
cur = &nlcth->helper;
if (strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN))
@@ -433,7 +432,7 @@ static int nfnl_cthelper_new(struct net *net, struct sock
*nfnl,
}
if (helper == NULL)
- ret = nfnl_cthelper_create(tb, &tuple);
+ ret = nfnl_cthelper_create(tb, &tuple, net);
else
ret = nfnl_cthelper_update(tb, helper);
@@ -561,6 +560,7 @@ static int
nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
{
struct nf_conntrack_helper *cur, *last;
+ struct net *net = sock_net(skb->sk);
rcu_read_lock();
last = (struct nf_conntrack_helper *)cb->args[1];
@@ -568,6 +568,8 @@ nfnl_cthelper_dump_table(struct sk_buff *skb, struct
netlink_callback *cb)
restart:
hlist_for_each_entry_rcu(cur,
&nf_ct_helper_hash[cb->args[0]], hnode) {
+ if (!net_eq(net, nf_ct_helper_net(cur)))
+ continue;
/* skip non-userspace conntrack helpers. */
if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
@@ -627,7 +629,7 @@ static int nfnl_cthelper_get(struct net *net, struct sock
*nfnl,
tuple_set = true;
}
- list_for_each_entry(nlcth, &nfnl_cthelper_list, list) {
+ list_for_each_entry(nlcth, &net->ct.nfnl_cthelper_list, list) {
cur = &nlcth->helper;
if (helper_name &&
strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN))
@@ -687,7 +689,7 @@ static int nfnl_cthelper_del(struct net *net, struct sock
*nfnl,
}
ret = -ENOENT;
- list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) {
+ list_for_each_entry_safe(nlcth, n, &net->ct.nfnl_cthelper_list, list) {
cur = &nlcth->helper;
j++;
@@ -743,34 +745,58 @@ static const struct nfnetlink_subsystem
nfnl_cthelper_subsys = {
MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER);
+static int __net_init nfnl_cthelper_net_init(struct net *net)
+{
+ INIT_LIST_HEAD(&net->ct.nfnl_cthelper_list);
+ return 0;
+}
+
+static void __net_exit nfnl_cthelper_net_exit(struct net *net)
+{
+ struct nf_conntrack_helper *cur;
+ struct nfnl_cthelper *nlcth, *n;
+
+ list_for_each_entry_safe(nlcth, n, &net->ct.nfnl_cthelper_list, list) {
+ cur = &nlcth->helper;
+
+ nf_conntrack_helper_unregister(net, cur);
+ list_del(&nlcth->list);
+
+ nf_ct_helper_put(cur);
+ }
+}
+
+static struct pernet_operations nfnl_cthelper_net_ops = {
+ .init = nfnl_cthelper_net_init,
+ .exit = nfnl_cthelper_net_exit,
+};
+
static int __init nfnl_cthelper_init(void)
{
int ret;
+ BUILD_BUG_ON(offsetof(struct nfnl_cthelper, helper) != 0);
+
+ ret = register_pernet_subsys(&nfnl_cthelper_net_ops);
+ if (ret < 0)
+ return ret;
+
ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys);
if (ret < 0) {
pr_err("nfnl_cthelper: cannot register with nfnetlink.\n");
goto err_out;
}
return 0;
+
err_out:
+ unregister_pernet_subsys(&nfnl_cthelper_net_ops);
return ret;
}
static void __exit nfnl_cthelper_exit(void)
{
- struct nf_conntrack_helper *cur;
- struct nfnl_cthelper *nlcth, *n;
-
nfnetlink_subsys_unregister(&nfnl_cthelper_subsys);
-
- list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) {
- cur = &nlcth->helper;
-
- nf_conntrack_helper_unregister(&init_net, cur);
- kfree(cur->expect_policy);
- kfree(nlcth);
- }
+ unregister_pernet_subsys(&nfnl_cthelper_net_ops);
}
module_init(nfnl_cthelper_init);
--
2.5.5
--
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