netfilter: nfnetlink_osf: extract nfnetlink_subsystem code from xt_osf.c
Move nfnetlink osf subsystem from xt_osf.c to standalone module so we can
reuse it from the new nft_ost extension.
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/xt_osf.c b/net/netfilter/xt_osf.c
index 9cfef73..bf7bba8 100644
--- a/net/netfilter/xt_osf.c
+++ b/net/netfilter/xt_osf.c
@@ -37,118 +37,6 @@
#include <net/netfilter/nf_log.h>
#include <linux/netfilter/xt_osf.h>
-/*
- * Indexed by dont-fragment bit.
- * It is the only constant value in the fingerprint.
- */
-static struct list_head xt_osf_fingers[2];
-
-static const struct nla_policy xt_osf_policy[OSF_ATTR_MAX + 1] = {
- [OSF_ATTR_FINGER] = { .len = sizeof(struct xt_osf_user_finger) },
-};
-
-static int xt_osf_add_callback(struct net *net, struct sock *ctnl,
- struct sk_buff *skb, const struct nlmsghdr *nlh,
- const struct nlattr * const osf_attrs[],
- struct netlink_ext_ack *extack)
-{
- struct xt_osf_user_finger *f;
- struct xt_osf_finger *kf = NULL, *sf;
- int err = 0;
-
- if (!capable(CAP_NET_ADMIN))
- return -EPERM;
-
- if (!osf_attrs[OSF_ATTR_FINGER])
- return -EINVAL;
-
- if (!(nlh->nlmsg_flags & NLM_F_CREATE))
- return -EINVAL;
-
- f = nla_data(osf_attrs[OSF_ATTR_FINGER]);
-
- kf = kmalloc(sizeof(struct xt_osf_finger), GFP_KERNEL);
- if (!kf)
- return -ENOMEM;
-
- memcpy(&kf->finger, f, sizeof(struct xt_osf_user_finger));
-
- list_for_each_entry(sf, &xt_osf_fingers[!!f->df], finger_entry) {
- if (memcmp(&sf->finger, f, sizeof(struct xt_osf_user_finger)))
- continue;
-
- kfree(kf);
- kf = NULL;
-
- if (nlh->nlmsg_flags & NLM_F_EXCL)
- err = -EEXIST;
- break;
- }
-
- /*
- * We are protected by nfnl mutex.
- */
- if (kf)
- list_add_tail_rcu(&kf->finger_entry, &xt_osf_fingers[!!f->df]);
-
- return err;
-}
-
-static int xt_osf_remove_callback(struct net *net, struct sock *ctnl,
- struct sk_buff *skb,
- const struct nlmsghdr *nlh,
- const struct nlattr * const osf_attrs[],
- struct netlink_ext_ack *extack)
-{
- struct xt_osf_user_finger *f;
- struct xt_osf_finger *sf;
- int err = -ENOENT;
-
- if (!capable(CAP_NET_ADMIN))
- return -EPERM;
-
- if (!osf_attrs[OSF_ATTR_FINGER])
- return -EINVAL;
-
- f = nla_data(osf_attrs[OSF_ATTR_FINGER]);
-
- list_for_each_entry(sf, &xt_osf_fingers[!!f->df], finger_entry) {
- if (memcmp(&sf->finger, f, sizeof(struct xt_osf_user_finger)))
- continue;
-
- /*
- * We are protected by nfnl mutex.
- */
- list_del_rcu(&sf->finger_entry);
- kfree_rcu(sf, rcu_head);
-
- err = 0;
- break;
- }
-
- return err;
-}
-
-static const struct nfnl_callback xt_osf_nfnetlink_callbacks[OSF_MSG_MAX] = {
- [OSF_MSG_ADD] = {
- .call = xt_osf_add_callback,
- .attr_count = OSF_ATTR_MAX,
- .policy = xt_osf_policy,
- },
- [OSF_MSG_REMOVE] = {
- .call = xt_osf_remove_callback,
- .attr_count = OSF_ATTR_MAX,
- .policy = xt_osf_policy,
- },
-};
-
-static const struct nfnetlink_subsystem xt_osf_nfnetlink = {
- .name = "osf",
- .subsys_id = NFNL_SUBSYS_OSF,
- .cb_count = OSF_MSG_MAX,
- .cb = xt_osf_nfnetlink_callbacks,
-};
-
static bool
xt_osf_match_packet(const struct sk_buff *skb, struct xt_action_param *p)
{
@@ -159,7 +47,7 @@ xt_osf_match_packet(const struct sk_buff *skb, struct xt_action_param *p)
return false;
return nf_osf_match(skb, xt_family(p), xt_hooknum(p), xt_in(p),
- xt_out(p), info, net, xt_osf_fingers);
+ xt_out(p), info, net, nf_osf_fingers);
}
static struct xt_match xt_osf_match = {
@@ -177,52 +65,21 @@ static struct xt_match xt_osf_match = {
static int __init xt_osf_init(void)
{
- int err = -EINVAL;
- int i;
-
- for (i=0; i<ARRAY_SIZE(xt_osf_fingers); ++i)
- INIT_LIST_HEAD(&xt_osf_fingers[i]);
-
- err = nfnetlink_subsys_register(&xt_osf_nfnetlink);
- if (err < 0) {
- pr_err("Failed to register OSF nsfnetlink helper (%d)\n", err);
- goto err_out_exit;
- }
+ int err;
err = xt_register_match(&xt_osf_match);
if (err) {
pr_err("Failed to register OS fingerprint "
"matching module (%d)\n", err);
- goto err_out_remove;
+ return err;
}
return 0;
-
-err_out_remove:
- nfnetlink_subsys_unregister(&xt_osf_nfnetlink);
-err_out_exit:
- return err;
}
static void __exit xt_osf_fini(void)
{
- struct xt_osf_finger *f;
- int i;
-
- nfnetlink_subsys_unregister(&xt_osf_nfnetlink);
xt_unregister_match(&xt_osf_match);
-
- rcu_read_lock();
- for (i=0; i<ARRAY_SIZE(xt_osf_fingers); ++i) {
-
- list_for_each_entry_rcu(f, &xt_osf_fingers[i], finger_entry) {
- list_del_rcu(&f->finger_entry);
- kfree_rcu(f, rcu_head);
- }
- }
- rcu_read_unlock();
-
- rcu_barrier();
}
module_init(xt_osf_init);
