netfilter: add missing IS_ENABLED(CONFIG_NF_CONNTRACK) checks to some header-files.

struct nf_conn contains a "struct nf_conntrack ct_general" member and
struct net contains a "struct netns_ct ct" member which are both only
defined in CONFIG_NF_CONNTRACK is enabled.  These members are used in a
number of inline functions defined in other header-files.  Added
preprocessor checks to make sure the headers will compile if
CONFIG_NF_CONNTRACK is disabled.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netfilter/nf_conntrack.h

@@ -59,6 +59,7 @@ struct nf_conntrack_net {
 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
 
 struct nf_conn {
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
 	/* Usage count in here is 1 for hash table, 1 per skb,
 	 * plus 1 for any connection(s) we are `master' for
 	 *
@@ -68,6 +69,7 @@ struct nf_conn {
 	 * beware nf_ct_get() is different and don't inc refcnt.
 	 */
 	struct nf_conntrack ct_general;
+#endif
 
 	spinlock_t	lock;
 	/* jiffies32 when this ct is considered dead */
@@ -148,6 +150,8 @@ void nf_conntrack_alter_reply(struct nf_conn *ct,
 int nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 			     const struct nf_conn *ignored_conntrack);
 
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+
 #define NFCT_INFOMASK	7UL
 #define NFCT_PTRMASK	~(NFCT_INFOMASK)
 
@@ -167,6 +171,8 @@ static inline void nf_ct_put(struct nf_conn *ct)
 	nf_conntrack_put(&ct->ct_general);
 }
 
+#endif
+
 /* Protocol module loading */
 int nf_ct_l3proto_try_module_get(unsigned short l3proto);
 void nf_ct_l3proto_module_put(unsigned short l3proto);
@@ -318,12 +324,16 @@ void nf_ct_tmpl_free(struct nf_conn *tmpl);
 
 u32 nf_ct_get_id(const struct nf_conn *ct);
 
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+
 static inline void
 nf_ct_set(struct sk_buff *skb, struct nf_conn *ct, enum ip_conntrack_info info)
 {
 	skb->_nfct = (unsigned long)ct | info;
 }
 
+#endif
+
 #define NF_CT_STAT_INC(net, count)	  __this_cpu_inc((net)->ct.stat->count)
 #define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
 #define NF_CT_STAT_ADD_ATOMIC(net, count, v) this_cpu_add((net)->ct.stat->count, (v))

include/net/netfilter/nf_conntrack_acct.h

@@ -29,6 +29,7 @@ struct nf_conn_acct *nf_conn_acct_find(const struct nf_conn *ct)
 static inline
 struct nf_conn_acct *nf_ct_acct_ext_add(struct nf_conn *ct, gfp_t gfp)
 {
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
 	struct net *net = nf_ct_net(ct);
 	struct nf_conn_acct *acct;
 
@@ -41,22 +42,34 @@ struct nf_conn_acct *nf_ct_acct_ext_add(struct nf_conn *ct, gfp_t gfp)
 
 
 	return acct;
+#else
+	return NULL;
+#endif
 };
 
 /* Check if connection tracking accounting is enabled */
 static inline bool nf_ct_acct_enabled(struct net *net)
 {
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
 	return net->ct.sysctl_acct != 0;
+#else
+	return false;
+#endif
 }
 
 /* Enable/disable connection tracking accounting */
 static inline void nf_ct_set_acct(struct net *net, bool enable)
 {
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
 	net->ct.sysctl_acct = enable;
+#endif
 }
 
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
 void nf_conntrack_acct_pernet_init(struct net *net);
 
 int nf_conntrack_acct_init(void);
 void nf_conntrack_acct_fini(void);
+#endif /* IS_ENABLED(CONFIG_NF_CONNTRACK) */
+
 #endif /* _NF_CONNTRACK_ACCT_H */

include/net/netfilter/nf_conntrack_l4proto.h

@@ -176,6 +176,7 @@ void nf_ct_l4proto_log_invalid(const struct sk_buff *skb,
 			       const char *fmt, ...) { }
 #endif /* CONFIG_SYSCTL */
 
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
 static inline struct nf_generic_net *nf_generic_pernet(struct net *net)
 {
        return &net->ct.nf_ct_proto.generic;
@@ -200,6 +201,7 @@ static inline struct nf_icmp_net *nf_icmpv6_pernet(struct net *net)
 {
        return &net->ct.nf_ct_proto.icmpv6;
 }
+#endif
 
 #ifdef CONFIG_NF_CT_PROTO_DCCP
 static inline struct nf_dccp_net *nf_dccp_pernet(struct net *net)

include/net/netfilter/nf_conntrack_timestamp.h

@@ -40,12 +40,18 @@ struct nf_conn_tstamp *nf_ct_tstamp_ext_add(struct nf_conn *ct, gfp_t gfp)
 
 static inline bool nf_ct_tstamp_enabled(struct net *net)
 {
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
 	return net->ct.sysctl_tstamp != 0;
+#else
+	return false;
+#endif
 }
 
 static inline void nf_ct_set_tstamp(struct net *net, bool enable)
 {
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
 	net->ct.sysctl_tstamp = enable;
+#endif
 }
 
 #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP