netfilter: nf_ct_helper: implement variable length helper private data

This patch uses the new variable length conntrack extensions.

Instead of using union nf_conntrack_help that contain all the
helper private data information, we allocate variable length
area to store the private helper data.

This patch includes the modification of all existing helpers.
It also includes a couple of include header to avoid compilation
warnings.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

3 files changed, 19 insertions, 33 deletions

diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h
index 0ce91d56a5f..0dfc8b7210a 100644
--- a/include/linux/netfilter/nf_conntrack_sip.h
+++ b/include/linux/netfilter/nf_conntrack_sip.h
@@ -2,6 +2,8 @@
 #define __NF_CONNTRACK_SIP_H__
 #ifdef __KERNEL__
 
+#include <net/netfilter/nf_conntrack_expect.h>
+
 #define SIP_PORT	5060
 #define SIP_TIMEOUT	3600
 
diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index cce7f6a798b..f1494feba79 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -39,36 +39,6 @@ union nf_conntrack_expect_proto {
 	/* insert expect proto private data here */
 };
 
-/* Add protocol helper include file here */
-#include <linux/netfilter/nf_conntrack_ftp.h>
-#include <linux/netfilter/nf_conntrack_pptp.h>
-#include <linux/netfilter/nf_conntrack_h323.h>
-#include <linux/netfilter/nf_conntrack_sane.h>
-#include <linux/netfilter/nf_conntrack_sip.h>
-
-/* per conntrack: application helper private data */
-union nf_conntrack_help {
-	/* insert conntrack helper private data (master) here */
-#if defined(CONFIG_NF_CONNTRACK_FTP) || defined(CONFIG_NF_CONNTRACK_FTP_MODULE)
-	struct nf_ct_ftp_master ct_ftp_info;
-#endif
-#if defined(CONFIG_NF_CONNTRACK_PPTP) || \
-    defined(CONFIG_NF_CONNTRACK_PPTP_MODULE)
-	struct nf_ct_pptp_master ct_pptp_info;
-#endif
-#if defined(CONFIG_NF_CONNTRACK_H323) || \
-    defined(CONFIG_NF_CONNTRACK_H323_MODULE)
-	struct nf_ct_h323_master ct_h323_info;
-#endif
-#if defined(CONFIG_NF_CONNTRACK_SANE) || \
-    defined(CONFIG_NF_CONNTRACK_SANE_MODULE)
-	struct nf_ct_sane_master ct_sane_info;
-#endif
-#if defined(CONFIG_NF_CONNTRACK_SIP) || defined(CONFIG_NF_CONNTRACK_SIP_MODULE)
-	struct nf_ct_sip_master ct_sip_info;
-#endif
-};
-
 #include <linux/types.h>
 #include <linux/skbuff.h>
 #include <linux/timer.h>
@@ -89,12 +59,13 @@ struct nf_conn_help {
 	/* Helper. if any */
 	struct nf_conntrack_helper __rcu *helper;
 
-	union nf_conntrack_help help;
-
 	struct hlist_head expectations;
 
 	/* Current number of expected connections */
 	u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
+
+	/* private helper information. */
+	char data[];
 };
 
 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h
index 5f5a4d9d4df..061352f71a8 100644
--- a/include/net/netfilter/nf_conntrack_helper.h
+++ b/include/net/netfilter/nf_conntrack_helper.h
@@ -11,6 +11,7 @@
 #define _NF_CONNTRACK_HELPER_H
 #include <net/netfilter/nf_conntrack.h>
 #include <net/netfilter/nf_conntrack_extend.h>
+#include <net/netfilter/nf_conntrack_expect.h>
 
 struct module;
 
@@ -23,6 +24,9 @@ struct nf_conntrack_helper {
 	struct module *me;		/* pointer to self */
 	const struct nf_conntrack_expect_policy *expect_policy;
 
+	/* length of internal data, ie. sizeof(struct nf_ct_*_master) */
+	size_t data_len;
+
 	/* Tuple of things we will help (compared against server response) */
 	struct nf_conntrack_tuple tuple;
 
@@ -48,7 +52,7 @@ nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum);
 extern int nf_conntrack_helper_register(struct nf_conntrack_helper *);
 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 struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, struct nf_conntrack_helper *helper, gfp_t gfp);
 
 extern int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
 				     gfp_t flags);
@@ -60,6 +64,15 @@ static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
 	return nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
 }
 
+static inline void *nfct_help_data(const struct nf_conn *ct)
+{
+	struct nf_conn_help *help;
+
+	help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
+
+	return (void *)help->data;
+}
+
 extern int nf_conntrack_helper_init(struct net *net);
 extern void nf_conntrack_helper_fini(struct net *net);