netfilter: nfnetlink_osf: extract nfnetlink_subsystem code from xt_osf.c
authorFernando Fernandez Mancera <ffmancera@riseup.net>
Tue, 24 Jul 2018 23:32:45 +0000 (01:32 +0200)
committerPablo Neira Ayuso <pablo@netfilter.org>
Mon, 30 Jul 2018 12:07:11 +0000 (14:07 +0200)
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>
include/uapi/linux/netfilter/nf_osf.h
include/uapi/linux/netfilter/xt_osf.h
net/netfilter/nfnetlink_osf.c
net/netfilter/xt_osf.c

index 3738116..cc2487f 100644 (file)
@@ -70,6 +70,8 @@ struct nf_osf_nlmsg {
        struct tcphdr                   tcp;
 };
 
+extern struct list_head nf_osf_fingers[2];
+
 /* Defines for IANA option kinds */
 enum iana_options {
        OSFOPT_EOL = 0,         /* End of options */
@@ -94,4 +96,13 @@ enum nf_osf_attr_type {
        OSF_ATTR_MAX,
 };
 
+/*
+ * Add/remove fingerprint from the kernel.
+ */
+enum nf_osf_msg_types {
+       OSF_MSG_ADD,
+       OSF_MSG_REMOVE,
+       OSF_MSG_MAX,
+};
+
 #endif /* _NF_OSF_H */
index b189007..a90e90c 100644 (file)
 #define xt_osf_nlmsg           nf_osf_nlmsg
 
 #define xt_osf_attr_type       nf_osf_attr_type
-/*
- * Add/remove fingerprint from the kernel.
- */
-enum xt_osf_msg_types {
-       OSF_MSG_ADD,
-       OSF_MSG_REMOVE,
-       OSF_MSG_MAX,
-};
+#define xt_osf_msg_types       nf_osf_msg_types
 
 #endif                         /* _XT_OSF_H */
index f4c75e9..ba0fa11 100644 (file)
 #include <net/netfilter/nf_log.h>
 #include <linux/netfilter/nf_osf.h>
 
+/*
+ * Indexed by dont-fragment bit.
+ * It is the only constant value in the fingerprint.
+ */
+struct list_head nf_osf_fingers[2];
+EXPORT_SYMBOL_GPL(nf_osf_fingers);
+
 static inline int nf_osf_ttl(const struct sk_buff *skb,
                             int ttl_check, unsigned char f_ttl)
 {
@@ -279,4 +286,151 @@ const char *nf_osf_find(const struct sk_buff *skb,
 }
 EXPORT_SYMBOL_GPL(nf_osf_find);
 
+static const struct nla_policy nfnl_osf_policy[OSF_ATTR_MAX + 1] = {
+       [OSF_ATTR_FINGER]       = { .len = sizeof(struct nf_osf_user_finger) },
+};
+
+static int nfnl_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 nf_osf_user_finger *f;
+       struct nf_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 nf_osf_finger), GFP_KERNEL);
+       if (!kf)
+               return -ENOMEM;
+
+       memcpy(&kf->finger, f, sizeof(struct nf_osf_user_finger));
+
+       list_for_each_entry(sf, &nf_osf_fingers[!!f->df], finger_entry) {
+               if (memcmp(&sf->finger, f, sizeof(struct nf_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, &nf_osf_fingers[!!f->df]);
+
+       return err;
+}
+
+static int nfnl_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 nf_osf_user_finger *f;
+       struct nf_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, &nf_osf_fingers[!!f->df], finger_entry) {
+               if (memcmp(&sf->finger, f, sizeof(struct nf_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 nfnl_osf_callbacks[OSF_MSG_MAX] = {
+       [OSF_MSG_ADD]   = {
+               .call           = nfnl_osf_add_callback,
+               .attr_count     = OSF_ATTR_MAX,
+               .policy         = nfnl_osf_policy,
+       },
+       [OSF_MSG_REMOVE]        = {
+               .call           = nfnl_osf_remove_callback,
+               .attr_count     = OSF_ATTR_MAX,
+               .policy         = nfnl_osf_policy,
+       },
+};
+
+static const struct nfnetlink_subsystem nfnl_osf_subsys = {
+       .name                   = "osf",
+       .subsys_id              = NFNL_SUBSYS_OSF,
+       .cb_count               = OSF_MSG_MAX,
+       .cb                     = nfnl_osf_callbacks,
+};
+
+static int __init nfnl_osf_init(void)
+{
+       int err = -EINVAL;
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(nf_osf_fingers); ++i)
+               INIT_LIST_HEAD(&nf_osf_fingers[i]);
+
+       err = nfnetlink_subsys_register(&nfnl_osf_subsys);
+       if (err < 0) {
+               pr_err("Failed to register OSF nsfnetlink helper (%d)\n", err);
+               goto err_out_exit;
+       }
+       return 0;
+
+err_out_exit:
+       return err;
+}
+
+static void __exit nfnl_osf_fini(void)
+{
+       struct nf_osf_finger *f;
+       int i;
+
+       nfnetlink_subsys_unregister(&nfnl_osf_subsys);
+
+       rcu_read_lock();
+       for (i = 0; i < ARRAY_SIZE(nf_osf_fingers); ++i) {
+               list_for_each_entry_rcu(f, &nf_osf_fingers[i], finger_entry) {
+                       list_del_rcu(&f->finger_entry);
+                       kfree_rcu(f, rcu_head);
+               }
+       }
+       rcu_read_unlock();
+
+       rcu_barrier();
+}
+
+module_init(nfnl_osf_init);
+module_exit(nfnl_osf_fini);
+
 MODULE_LICENSE("GPL");
index 9cfef73..bf7bba8 100644 (file)
 #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);