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-rw-r--r--include/net/netfilter/nf_conntrack_helper.h5
-rw-r--r--net/netfilter/nf_conntrack_core.c28
-rw-r--r--net/netfilter/nf_conntrack_helper.c32
-rw-r--r--net/netfilter/nf_conntrack_netlink.c70
4 files changed, 95 insertions, 40 deletions
diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h
index f8060ab5a083..66d65a7caa39 100644
--- a/include/net/netfilter/nf_conntrack_helper.h
+++ b/include/net/netfilter/nf_conntrack_helper.h
@@ -39,9 +39,6 @@ struct nf_conntrack_helper
};
extern struct nf_conntrack_helper *
-__nf_ct_helper_find(const struct nf_conntrack_tuple *tuple);
-
-extern struct nf_conntrack_helper *
__nf_conntrack_helper_find_byname(const char *name);
extern int nf_conntrack_helper_register(struct nf_conntrack_helper *);
@@ -49,6 +46,8 @@ extern void nf_conntrack_helper_unregister(struct nf_conntrack_helper *);
extern struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp);
+extern int __nf_ct_try_assign_helper(struct nf_conn *ct, gfp_t flags);
+
static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
{
return nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 622d7c671cb7..1e649fb9e0df 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -588,14 +588,7 @@ init_conntrack(struct net *net,
nf_conntrack_get(&ct->master->ct_general);
NF_CT_STAT_INC(net, expect_new);
} else {
- struct nf_conntrack_helper *helper;
-
- helper = __nf_ct_helper_find(&repl_tuple);
- if (helper) {
- help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
- if (help)
- rcu_assign_pointer(help->helper, helper);
- }
+ __nf_ct_try_assign_helper(ct, GFP_ATOMIC);
NF_CT_STAT_INC(net, new);
}
@@ -772,7 +765,6 @@ void nf_conntrack_alter_reply(struct nf_conn *ct,
const struct nf_conntrack_tuple *newreply)
{
struct nf_conn_help *help = nfct_help(ct);
- struct nf_conntrack_helper *helper;
/* Should be unconfirmed, so not in hash table yet */
NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
@@ -785,23 +777,7 @@ void nf_conntrack_alter_reply(struct nf_conn *ct,
return;
rcu_read_lock();
- helper = __nf_ct_helper_find(newreply);
- if (helper == NULL) {
- if (help)
- rcu_assign_pointer(help->helper, NULL);
- goto out;
- }
-
- if (help == NULL) {
- help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
- if (help == NULL)
- goto out;
- } else {
- memset(&help->help, 0, sizeof(help->help));
- }
-
- rcu_assign_pointer(help->helper, helper);
-out:
+ __nf_ct_try_assign_helper(ct, GFP_ATOMIC);
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index 9c06b9f86ad4..9e4b74b95ce8 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -44,7 +44,7 @@ static unsigned int helper_hash(const struct nf_conntrack_tuple *tuple)
(__force __u16)tuple->src.u.all) % nf_ct_helper_hsize;
}
-struct nf_conntrack_helper *
+static struct nf_conntrack_helper *
__nf_ct_helper_find(const struct nf_conntrack_tuple *tuple)
{
struct nf_conntrack_helper *helper;
@@ -62,7 +62,6 @@ __nf_ct_helper_find(const struct nf_conntrack_tuple *tuple)
}
return NULL;
}
-EXPORT_SYMBOL_GPL(__nf_ct_helper_find);
struct nf_conntrack_helper *
__nf_conntrack_helper_find_byname(const char *name)
@@ -94,6 +93,35 @@ struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp)
}
EXPORT_SYMBOL_GPL(nf_ct_helper_ext_add);
+int __nf_ct_try_assign_helper(struct nf_conn *ct, gfp_t flags)
+{
+ int ret = 0;
+ struct nf_conntrack_helper *helper;
+ struct nf_conn_help *help = nfct_help(ct);
+
+ helper = __nf_ct_helper_find(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+ if (helper == NULL) {
+ if (help)
+ rcu_assign_pointer(help->helper, NULL);
+ goto out;
+ }
+
+ if (help == NULL) {
+ help = nf_ct_helper_ext_add(ct, flags);
+ if (help == NULL) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ } else {
+ memset(&help->help, 0, sizeof(help->help));
+ }
+
+ rcu_assign_pointer(help->helper, helper);
+out:
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__nf_ct_try_assign_helper);
+
static inline int unhelp(struct nf_conntrack_tuple_hash *i,
const struct nf_conntrack_helper *me)
{
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 49a04fa0becc..4f6486cfd337 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -917,8 +917,22 @@ ctnetlink_change_helper(struct nf_conn *ct, struct nlattr *cda[])
}
helper = __nf_conntrack_helper_find_byname(helpname);
- if (helper == NULL)
+ if (helper == NULL) {
+#ifdef CONFIG_MODULES
+ spin_unlock_bh(&nf_conntrack_lock);
+
+ if (request_module("nfct-helper-%s", helpname) < 0) {
+ spin_lock_bh(&nf_conntrack_lock);
+ return -EOPNOTSUPP;
+ }
+
+ spin_lock_bh(&nf_conntrack_lock);
+ helper = __nf_conntrack_helper_find_byname(helpname);
+ if (helper)
+ return -EAGAIN;
+#endif
return -EOPNOTSUPP;
+ }
if (help) {
if (help->helper == helper)
@@ -1082,7 +1096,6 @@ ctnetlink_create_conntrack(struct nlattr *cda[],
{
struct nf_conn *ct;
int err = -EINVAL;
- struct nf_conn_help *help;
struct nf_conntrack_helper *helper;
ct = nf_conntrack_alloc(&init_net, otuple, rtuple, GFP_KERNEL);
@@ -1097,16 +1110,55 @@ ctnetlink_create_conntrack(struct nlattr *cda[],
ct->status |= IPS_CONFIRMED;
rcu_read_lock();
- helper = __nf_ct_helper_find(rtuple);
- if (helper) {
- help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
- if (help == NULL) {
+ if (cda[CTA_HELP]) {
+ char *helpname;
+
+ err = ctnetlink_parse_help(cda[CTA_HELP], &helpname);
+ if (err < 0) {
+ rcu_read_unlock();
+ goto err;
+ }
+
+ helper = __nf_conntrack_helper_find_byname(helpname);
+ if (helper == NULL) {
+ rcu_read_unlock();
+#ifdef CONFIG_MODULES
+ if (request_module("nfct-helper-%s", helpname) < 0) {
+ err = -EOPNOTSUPP;
+ goto err;
+ }
+
+ rcu_read_lock();
+ helper = __nf_conntrack_helper_find_byname(helpname);
+ if (helper) {
+ rcu_read_unlock();
+ err = -EAGAIN;
+ goto err;
+ }
+ rcu_read_unlock();
+#endif
+ err = -EOPNOTSUPP;
+ goto err;
+ } else {
+ struct nf_conn_help *help;
+
+ help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
+ if (help == NULL) {
+ rcu_read_unlock();
+ err = -ENOMEM;
+ goto err;
+ }
+
+ /* not in hash table yet so not strictly necessary */
+ rcu_assign_pointer(help->helper, helper);
+ }
+ } else {
+ /* try an implicit helper assignation */
+ err = __nf_ct_try_assign_helper(ct, GFP_ATOMIC);
+ if (err < 0) {
rcu_read_unlock();
- err = -ENOMEM;
goto err;
}
- /* not in hash table yet so not strictly necessary */
- rcu_assign_pointer(help->helper, helper);
}
if (cda[CTA_STATUS]) {
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.