[NETFILTER]: nf_conntrack: use extension infrastructure for helper

Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index c31382d..f1e0fee 100644 (file)
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -294,32 +294,6 @@ static inline struct nf_conn_nat *nfct_nat(const struct nf_conn *ct)
        offset = ALIGN(offset, __alignof__(struct nf_conn_nat));
        return (struct nf_conn_nat *) ((void *)ct + offset);
 }
-
-static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
-{
-       unsigned int offset = sizeof(struct nf_conn);
-
-       if (!(ct->features & NF_CT_F_HELP))
-               return NULL;
-       if (ct->features & NF_CT_F_NAT) {
-               offset = ALIGN(offset, __alignof__(struct nf_conn_nat));
-               offset += sizeof(struct nf_conn_nat);
-       }
-
-       offset = ALIGN(offset, __alignof__(struct nf_conn_help));
-       return (struct nf_conn_help *) ((void *)ct + offset);
-}
-#else /* No NAT */
-static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
-{
-       unsigned int offset = sizeof(struct nf_conn);
-
-       if (!(ct->features & NF_CT_F_HELP))
-               return NULL;
-
-       offset = ALIGN(offset, __alignof__(struct nf_conn_help));
-       return (struct nf_conn_help *) ((void *)ct + offset);
-}
 #endif /* CONFIG_NF_NAT_NEEDED */
 #endif /* __KERNEL__ */
 #endif /* _NF_CONNTRACK_H */

diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h
index 9fb9066..3bf7d05 100644 (file)
--- a/include/net/netfilter/nf_conntrack_core.h
+++ b/include/net/netfilter/nf_conntrack_core.h
@@ -30,6 +30,9 @@ extern void nf_conntrack_cleanup(void);
 extern int nf_conntrack_proto_init(void);
 extern void nf_conntrack_proto_fini(void);
 
+extern int nf_conntrack_helper_init(void);
+extern void nf_conntrack_helper_fini(void);
+
 struct nf_conntrack_l3proto;
 extern struct nf_conntrack_l3proto *nf_ct_find_l3proto(u_int16_t pf);
 /* Like above, but you already have conntrack read lock. */

diff --git a/include/net/netfilter/nf_conntrack_extend.h b/include/net/netfilter/nf_conntrack_extend.h
index 8a988d1..05357dc 100644 (file)
--- a/include/net/netfilter/nf_conntrack_extend.h
+++ b/include/net/netfilter/nf_conntrack_extend.h
@@ -5,9 +5,12 @@
 
 enum nf_ct_ext_id
 {
+       NF_CT_EXT_HELPER,
        NF_CT_EXT_NUM,
 };
 
+#define NF_CT_EXT_HELPER_TYPE struct nf_conn_help
+
 /* Extensions: optional stuff which isn't permanently in struct. */
 struct nf_ct_ext {
        u8 offset[NF_CT_EXT_NUM];

diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h
index 8c72ac9..b43a75b 100644 (file)
--- a/include/net/netfilter/nf_conntrack_helper.h
+++ b/include/net/netfilter/nf_conntrack_helper.h
@@ -10,6 +10,7 @@
 #ifndef _NF_CONNTRACK_HELPER_H
 #define _NF_CONNTRACK_HELPER_H
 #include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_extend.h>
 
 struct module;
 
@@ -52,4 +53,8 @@ extern void nf_ct_helper_put(struct nf_conntrack_helper *helper);
 extern int nf_conntrack_helper_register(struct nf_conntrack_helper *);
 extern void nf_conntrack_helper_unregister(struct nf_conntrack_helper *);
 
+static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
+{
+       return nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
+}
 #endif /*_NF_CONNTRACK_HELPER_H*/

diff --git a/net/ipv4/netfilter/nf_nat_standalone.c b/net/ipv4/netfilter/nf_nat_standalone.c
index 55dac36..0b2f0c3 100644 (file)
--- a/net/ipv4/netfilter/nf_nat_standalone.c
+++ b/net/ipv4/netfilter/nf_nat_standalone.c
@@ -338,14 +338,6 @@ static int __init nf_nat_standalone_init(void)
                return ret;
        }
 
-       size = ALIGN(size, __alignof__(struct nf_conn_help)) +
-              sizeof(struct nf_conn_help);
-       ret = nf_conntrack_register_cache(NF_CT_F_NAT|NF_CT_F_HELP,
-                                         "nf_nat:help", size);
-       if (ret < 0) {
-               printk(KERN_ERR "nf_nat_init: Unable to create slab cache\n");
-               goto cleanup_register_cache;
-       }
 #ifdef CONFIG_XFRM
        BUG_ON(ip_nat_decode_session != NULL);
        ip_nat_decode_session = nat_decode_session;
@@ -370,8 +362,6 @@ static int __init nf_nat_standalone_init(void)
        ip_nat_decode_session = NULL;
        synchronize_net();
 #endif
-       nf_conntrack_unregister_cache(NF_CT_F_NAT|NF_CT_F_HELP);
- cleanup_register_cache:
        nf_conntrack_unregister_cache(NF_CT_F_NAT);
        return ret;
 }

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index b56f954..914506e 100644 (file)
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -566,7 +566,6 @@ __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
                     u_int32_t features)
 {
        struct nf_conn *conntrack = NULL;
-       struct nf_conntrack_helper *helper;
 
        if (unlikely(!nf_conntrack_hash_rnd_initted)) {
                get_random_bytes(&nf_conntrack_hash_rnd, 4);
@@ -593,14 +592,6 @@ __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
        /*  find features needed by this conntrack. */
        features |= l3proto->get_features(orig);
 
-       /* FIXME: protect helper list per RCU */
-       read_lock_bh(&nf_conntrack_lock);
-       helper = __nf_ct_helper_find(repl);
-       /* NAT might want to assign a helper later */
-       if (helper || features & NF_CT_F_NAT)
-               features |= NF_CT_F_HELP;
-       read_unlock_bh(&nf_conntrack_lock);
-
        DEBUGP("nf_conntrack_alloc: features=0x%x\n", features);
 
        read_lock_bh(&nf_ct_cache_lock);
@@ -681,12 +672,6 @@ init_conntrack(const struct nf_conntrack_tuple *tuple,
                return NULL;
        }
 
-       read_lock_bh(&nf_conntrack_lock);
-       exp = __nf_conntrack_expect_find(tuple);
-       if (exp && exp->helper)
-               features = NF_CT_F_HELP;
-       read_unlock_bh(&nf_conntrack_lock);
-
        conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto, features);
        if (conntrack == NULL || IS_ERR(conntrack)) {
                DEBUGP("Can't allocate conntrack.\n");
@@ -701,16 +686,21 @@ init_conntrack(const struct nf_conntrack_tuple *tuple,
 
        write_lock_bh(&nf_conntrack_lock);
        exp = find_expectation(tuple);
-
-       help = nfct_help(conntrack);
        if (exp) {
                DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n",
                        conntrack, exp);
                /* Welcome, Mr. Bond.  We've been expecting you... */
                __set_bit(IPS_EXPECTED_BIT, &conntrack->status);
                conntrack->master = exp->master;
-               if (exp->helper)
-                       rcu_assign_pointer(help->helper, exp->helper);
+               if (exp->helper) {
+                       help = nf_ct_ext_add(conntrack, NF_CT_EXT_HELPER,
+                                            GFP_ATOMIC);
+                       if (help)
+                               rcu_assign_pointer(help->helper, exp->helper);
+                       else
+                               DEBUGP("failed to add helper extension area");
+               }
+
 #ifdef CONFIG_NF_CONNTRACK_MARK
                conntrack->mark = exp->master->mark;
 #endif
@@ -720,10 +710,18 @@ init_conntrack(const struct nf_conntrack_tuple *tuple,
                nf_conntrack_get(&conntrack->master->ct_general);
                NF_CT_STAT_INC(expect_new);
        } else {
-               if (help) {
-                       /* not in hash table yet, so not strictly necessary */
-                       rcu_assign_pointer(help->helper,
-                                          __nf_ct_helper_find(&repl_tuple));
+               struct nf_conntrack_helper *helper;
+
+               helper = __nf_ct_helper_find(&repl_tuple);
+               if (helper) {
+                       help = nf_ct_ext_add(conntrack, NF_CT_EXT_HELPER,
+                                            GFP_ATOMIC);
+                       if (help)
+                               /* not in hash table yet, so not strictly
+                                  necessary */
+                               rcu_assign_pointer(help->helper, helper);
+                       else
+                               DEBUGP("failed to add helper extension area");
                }
                NF_CT_STAT_INC(new);
        }
@@ -892,6 +890,7 @@ 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;
 
        write_lock_bh(&nf_conntrack_lock);
        /* Should be unconfirmed, so not in hash table yet */
@@ -901,14 +900,28 @@ void nf_conntrack_alter_reply(struct nf_conn *ct,
        NF_CT_DUMP_TUPLE(newreply);
 
        ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
-       if (!ct->master && help && help->expecting == 0) {
-               struct nf_conntrack_helper *helper;
-               helper = __nf_ct_helper_find(newreply);
-               if (helper)
-                       memset(&help->help, 0, sizeof(help->help));
-               /* not in hash table yet, so not strictly necessary */
-               rcu_assign_pointer(help->helper, helper);
+       if (ct->master || (help && help->expecting != 0))
+               goto out;
+
+       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_ext_add(ct, NF_CT_EXT_HELPER, GFP_ATOMIC);
+               if (help == NULL) {
+                       DEBUGP("failed to add helper extension area");
+                       goto out;
+               }
+       } else {
+               memset(&help->help, 0, sizeof(help->help));
+       }
+
+       rcu_assign_pointer(help->helper, helper);
+out:
        write_unlock_bh(&nf_conntrack_lock);
 }
 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
@@ -1150,6 +1163,7 @@ void nf_conntrack_cleanup(void)
                            nf_conntrack_htable_size);
 
        nf_conntrack_proto_fini();
+       nf_conntrack_helper_fini();
 }
 
 static struct list_head *alloc_hashtable(int size, int *vmalloced)
@@ -1272,6 +1286,10 @@ int __init nf_conntrack_init(void)
        if (ret < 0)
                goto out_free_expect_slab;
 
+       ret = nf_conntrack_helper_init();
+       if (ret < 0)
+               goto out_fini_proto;
+
        /* For use by REJECT target */
        rcu_assign_pointer(ip_ct_attach, __nf_conntrack_attach);
        rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
@@ -1284,6 +1302,8 @@ int __init nf_conntrack_init(void)
 
        return ret;
 
+out_fini_proto:
+       nf_conntrack_proto_fini();
 out_free_expect_slab:
        kmem_cache_destroy(nf_conntrack_expect_cachep);
 err_free_conntrack_slab:

diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index f868b7f..6d32399 100644 (file)
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -26,6 +26,7 @@
 #include <net/netfilter/nf_conntrack_l4proto.h>
 #include <net/netfilter/nf_conntrack_helper.h>
 #include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_extend.h>
 
 static __read_mostly LIST_HEAD(helpers);
 
@@ -100,18 +101,8 @@ static inline int unhelp(struct nf_conntrack_tuple_hash *i,
 
 int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
 {
-       int size, ret;
-
        BUG_ON(me->timeout == 0);
 
-       size = ALIGN(sizeof(struct nf_conn), __alignof__(struct nf_conn_help)) +
-              sizeof(struct nf_conn_help);
-       ret = nf_conntrack_register_cache(NF_CT_F_HELP, "nf_conntrack:help",
-                                         size);
-       if (ret < 0) {
-               printk(KERN_ERR "nf_conntrack_helper_register: Unable to create slab cache for conntracks\n");
-               return ret;
-       }
        write_lock_bh(&nf_conntrack_lock);
        list_add(&me->list, &helpers);
        write_unlock_bh(&nf_conntrack_lock);
@@ -153,3 +144,19 @@ void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me)
        synchronize_net();
 }
 EXPORT_SYMBOL_GPL(nf_conntrack_helper_unregister);
+
+struct nf_ct_ext_type helper_extend = {
+       .len    = sizeof(struct nf_conn_help),
+       .align  = __alignof__(struct nf_conn_help),
+       .id     = NF_CT_EXT_HELPER,
+};
+
+int nf_conntrack_helper_init()
+{
+       return nf_ct_extend_register(&helper_extend);
+}
+
+void nf_conntrack_helper_fini()
+{
+       nf_ct_extend_unregister(&helper_extend);
+}

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index d0fe3d7..3d56f36 100644 (file)
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -856,23 +856,23 @@ ctnetlink_change_helper(struct nf_conn *ct, struct nfattr *cda[])
                return 0;
        }
 
-       if (!help) {
-               /* FIXME: we need to reallocate and rehash */
-               return -EBUSY;
-       }
-
        helper = __nf_conntrack_helper_find_byname(helpname);
        if (helper == NULL)
                return -EINVAL;
 
-       if (help->helper == helper)
-               return 0;
-
-       if (help->helper)
-               return -EBUSY;
+       if (help) {
+               if (help->helper == helper)
+                       return 0;
+               if (help->helper)
+                       return -EBUSY;
+               /* need to zero data of old helper */
+               memset(&help->help, 0, sizeof(help->help));
+       } else {
+               help = nf_ct_ext_add(ct, NF_CT_EXT_HELPER, GFP_KERNEL);
+               if (help == NULL)
+                       return -ENOMEM;
+       }
 
-       /* need to zero data of old helper */
-       memset(&help->help, 0, sizeof(help->help));
        rcu_assign_pointer(help->helper, helper);
 
        return 0;
@@ -957,7 +957,7 @@ ctnetlink_create_conntrack(struct nfattr *cda[],
        struct nf_conn *ct;
        int err = -EINVAL;
        struct nf_conn_help *help;
-       struct nf_conntrack_helper *helper = NULL;
+       struct nf_conntrack_helper *helper;
 
        ct = nf_conntrack_alloc(otuple, rtuple);
        if (ct == NULL || IS_ERR(ct))
@@ -987,9 +987,14 @@ ctnetlink_create_conntrack(struct nfattr *cda[],
                ct->mark = ntohl(*(__be32 *)NFA_DATA(cda[CTA_MARK-1]));
 #endif
 
-       help = nfct_help(ct);
-       if (help) {
-               helper = nf_ct_helper_find_get(rtuple);
+       helper = nf_ct_helper_find_get(rtuple);
+       if (helper) {
+               help = nf_ct_ext_add(ct, NF_CT_EXT_HELPER, GFP_KERNEL);
+               if (help == NULL) {
+                       nf_ct_helper_put(helper);
+                       err = -ENOMEM;
+                       goto err;
+               }
                /* not in hash table yet so not strictly necessary */
                rcu_assign_pointer(help->helper, helper);
        }