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-rw-r--r--include/linux/netfilter/nf_conntrack_common.h1
-rw-r--r--include/net/netfilter/nf_conntrack_expect.h1
-rw-r--r--net/netfilter/nf_conntrack_expect.c62
-rw-r--r--net/netfilter/nf_conntrack_netlink.c46
4 files changed, 79 insertions, 31 deletions
diff --git a/include/linux/netfilter/nf_conntrack_common.h b/include/linux/netfilter/nf_conntrack_common.h
index fdc50cae861f..23a1a08578a8 100644
--- a/include/linux/netfilter/nf_conntrack_common.h
+++ b/include/linux/netfilter/nf_conntrack_common.h
@@ -103,6 +103,7 @@ enum ip_conntrack_expect_events {
/* expectation flags */
#define NF_CT_EXPECT_PERMANENT 0x1
#define NF_CT_EXPECT_INACTIVE 0x2
+#define NF_CT_EXPECT_USERSPACE 0x4
#ifdef __KERNEL__
struct ip_conntrack_stat {
diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h
index 96bb42af5fae..416b83844485 100644
--- a/include/net/netfilter/nf_conntrack_expect.h
+++ b/include/net/netfilter/nf_conntrack_expect.h
@@ -85,6 +85,7 @@ nf_ct_find_expectation(struct net *net, u16 zone,
void nf_ct_unlink_expect(struct nf_conntrack_expect *exp);
void nf_ct_remove_expectations(struct nf_conn *ct);
void nf_ct_unexpect_related(struct nf_conntrack_expect *exp);
+void nf_ct_remove_userspace_expectations(void);
/* Allocate space for an expectation: this is mandatory before calling
nf_ct_expect_related. You will have to call put afterwards. */
diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index acb29ccaa41f..b30a1f2aac00 100644
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -38,20 +38,23 @@ static int nf_ct_expect_hash_rnd_initted __read_mostly;
static struct kmem_cache *nf_ct_expect_cachep __read_mostly;
+static HLIST_HEAD(nf_ct_userspace_expect_list);
+
/* nf_conntrack_expect helper functions */
void nf_ct_unlink_expect(struct nf_conntrack_expect *exp)
{
struct nf_conn_help *master_help = nfct_help(exp->master);
struct net *net = nf_ct_exp_net(exp);
- NF_CT_ASSERT(master_help);
NF_CT_ASSERT(!timer_pending(&exp->timeout));
hlist_del_rcu(&exp->hnode);
net->ct.expect_count--;
hlist_del(&exp->lnode);
- master_help->expecting[exp->class]--;
+ if (!(exp->flags & NF_CT_EXPECT_USERSPACE))
+ master_help->expecting[exp->class]--;
+
nf_ct_expect_put(exp);
NF_CT_STAT_INC(net, expect_delete);
@@ -320,16 +323,21 @@ static void nf_ct_expect_insert(struct nf_conntrack_expect *exp)
atomic_inc(&exp->use);
- hlist_add_head(&exp->lnode, &master_help->expectations);
- master_help->expecting[exp->class]++;
+ if (master_help) {
+ hlist_add_head(&exp->lnode, &master_help->expectations);
+ master_help->expecting[exp->class]++;
+ } else if (exp->flags & NF_CT_EXPECT_USERSPACE)
+ hlist_add_head(&exp->lnode, &nf_ct_userspace_expect_list);
hlist_add_head_rcu(&exp->hnode, &net->ct.expect_hash[h]);
net->ct.expect_count++;
setup_timer(&exp->timeout, nf_ct_expectation_timed_out,
(unsigned long)exp);
- p = &master_help->helper->expect_policy[exp->class];
- exp->timeout.expires = jiffies + p->timeout * HZ;
+ if (master_help) {
+ p = &master_help->helper->expect_policy[exp->class];
+ exp->timeout.expires = jiffies + p->timeout * HZ;
+ }
add_timer(&exp->timeout);
atomic_inc(&exp->use);
@@ -380,7 +388,9 @@ static inline int __nf_ct_expect_check(struct nf_conntrack_expect *expect)
unsigned int h;
int ret = 1;
- if (!master_help->helper) {
+ /* Don't allow expectations created from kernel-space with no helper */
+ if (!(expect->flags & NF_CT_EXPECT_USERSPACE) &&
+ (!master_help || (master_help && !master_help->helper))) {
ret = -ESHUTDOWN;
goto out;
}
@@ -398,13 +408,16 @@ static inline int __nf_ct_expect_check(struct nf_conntrack_expect *expect)
}
}
/* Will be over limit? */
- p = &master_help->helper->expect_policy[expect->class];
- if (p->max_expected &&
- master_help->expecting[expect->class] >= p->max_expected) {
- evict_oldest_expect(master, expect);
- if (master_help->expecting[expect->class] >= p->max_expected) {
- ret = -EMFILE;
- goto out;
+ if (master_help) {
+ p = &master_help->helper->expect_policy[expect->class];
+ if (p->max_expected &&
+ master_help->expecting[expect->class] >= p->max_expected) {
+ evict_oldest_expect(master, expect);
+ if (master_help->expecting[expect->class]
+ >= p->max_expected) {
+ ret = -EMFILE;
+ goto out;
+ }
}
}
@@ -439,6 +452,21 @@ out:
}
EXPORT_SYMBOL_GPL(nf_ct_expect_related_report);
+void nf_ct_remove_userspace_expectations(void)
+{
+ struct nf_conntrack_expect *exp;
+ struct hlist_node *n, *next;
+
+ hlist_for_each_entry_safe(exp, n, next,
+ &nf_ct_userspace_expect_list, lnode) {
+ if (del_timer(&exp->timeout)) {
+ nf_ct_unlink_expect(exp);
+ nf_ct_expect_put(exp);
+ }
+ }
+}
+EXPORT_SYMBOL_GPL(nf_ct_remove_userspace_expectations);
+
#ifdef CONFIG_PROC_FS
struct ct_expect_iter_state {
struct seq_net_private p;
@@ -529,8 +557,12 @@ static int exp_seq_show(struct seq_file *s, void *v)
seq_printf(s, "PERMANENT");
delim = ",";
}
- if (expect->flags & NF_CT_EXPECT_INACTIVE)
+ if (expect->flags & NF_CT_EXPECT_INACTIVE) {
seq_printf(s, "%sINACTIVE", delim);
+ delim = ",";
+ }
+ if (expect->flags & NF_CT_EXPECT_USERSPACE)
+ seq_printf(s, "%sUSERSPACE", delim);
helper = rcu_dereference(nfct_help(expect->master)->helper);
if (helper) {
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 0804e0ef6500..b4077be5f663 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1560,8 +1560,8 @@ ctnetlink_exp_dump_expect(struct sk_buff *skb,
const struct nf_conntrack_expect *exp)
{
struct nf_conn *master = exp->master;
- struct nf_conntrack_helper *helper;
long timeout = (exp->timeout.expires - jiffies) / HZ;
+ struct nf_conn_help *help;
if (timeout < 0)
timeout = 0;
@@ -1578,9 +1578,14 @@ ctnetlink_exp_dump_expect(struct sk_buff *skb,
NLA_PUT_BE32(skb, CTA_EXPECT_TIMEOUT, htonl(timeout));
NLA_PUT_BE32(skb, CTA_EXPECT_ID, htonl((unsigned long)exp));
NLA_PUT_BE32(skb, CTA_EXPECT_FLAGS, htonl(exp->flags));
- helper = rcu_dereference(nfct_help(master)->helper);
- if (helper)
- NLA_PUT_STRING(skb, CTA_EXPECT_HELP_NAME, helper->name);
+ help = nfct_help(master);
+ if (help) {
+ struct nf_conntrack_helper *helper;
+
+ helper = rcu_dereference(help->helper);
+ if (helper)
+ NLA_PUT_STRING(skb, CTA_EXPECT_HELP_NAME, helper->name);
+ }
return 0;
@@ -1921,24 +1926,32 @@ ctnetlink_create_expect(struct net *net, u16 zone,
if (!h)
return -ENOENT;
ct = nf_ct_tuplehash_to_ctrack(h);
- help = nfct_help(ct);
-
- if (!help || !help->helper) {
- /* such conntrack hasn't got any helper, abort */
- err = -EOPNOTSUPP;
- goto out;
- }
-
exp = nf_ct_expect_alloc(ct);
if (!exp) {
err = -ENOMEM;
goto out;
}
+ help = nfct_help(ct);
+ if (!help) {
+ if (!cda[CTA_EXPECT_TIMEOUT]) {
+ err = -EINVAL;
+ goto out;
+ }
+ exp->timeout.expires =
+ jiffies + ntohl(nla_get_be32(cda[CTA_EXPECT_TIMEOUT])) * HZ;
- if (cda[CTA_EXPECT_FLAGS])
- exp->flags = ntohl(nla_get_be32(cda[CTA_EXPECT_FLAGS]));
- else
- exp->flags = 0;
+ exp->flags = NF_CT_EXPECT_USERSPACE;
+ if (cda[CTA_EXPECT_FLAGS]) {
+ exp->flags |=
+ ntohl(nla_get_be32(cda[CTA_EXPECT_FLAGS]));
+ }
+ } else {
+ if (cda[CTA_EXPECT_FLAGS]) {
+ exp->flags = ntohl(nla_get_be32(cda[CTA_EXPECT_FLAGS]));
+ exp->flags &= ~NF_CT_EXPECT_USERSPACE;
+ } else
+ exp->flags = 0;
+ }
exp->class = 0;
exp->expectfn = NULL;
@@ -2109,6 +2122,7 @@ static void __exit ctnetlink_exit(void)
{
pr_info("ctnetlink: unregistering from nfnetlink.\n");
+ nf_ct_remove_userspace_expectations();
#ifdef CONFIG_NF_CONNTRACK_EVENTS
nf_ct_expect_unregister_notifier(&ctnl_notifier_exp);
nf_conntrack_unregister_notifier(&ctnl_notifier);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.