netfilter: xtables: provide invoked family value to extensions

By passing in the family through which extensions were invoked, a bit
of data space can be reclaimed. The "family" member will be added to
the parameter structures and the check functions be adjusted.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 10 insertions, 2 deletions

diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index e3b3b669a143..be41b609c88f 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -183,6 +183,8 @@ struct xt_counters_info
  * @fragoff:    packet is a fragment, this is the data offset
  * @thoff:      position of transport header relative to skb->data
  * @hotdrop:    drop packet if we had inspection problems
+ * @family:     Actual NFPROTO_* through which the function is invoked
+ *              (helpful when match->family == NFPROTO_UNSPEC)
  */
 struct xt_match_param {
         const struct net_device *in, *out;
@@ -191,6 +193,7 @@ struct xt_match_param {
         int fragoff;
         unsigned int thoff;
         bool *hotdrop;
+        u_int8_t family;
 };
 
 /**
@@ -210,12 +213,14 @@ struct xt_mtchk_param {
         const struct xt_match *match;
         void *matchinfo;
         unsigned int hook_mask;
+        u_int8_t family;
 };
 
 /* Match destructor parameters */
 struct xt_mtdtor_param {
         const struct xt_match *match;
         void *matchinfo;
+        u_int8_t family;
 };
 
 /**
@@ -232,6 +237,7 @@ struct xt_target_param {
         unsigned int hooknum;
         const struct xt_target *target;
         const void *targinfo;
+        u_int8_t family;
 };
 
 /**
@@ -249,12 +255,14 @@ struct xt_tgchk_param {
         const struct xt_target *target;
         void *targinfo;
         unsigned int hook_mask;
+        u_int8_t family;
 };
 
 /* Target destructor parameters */
 struct xt_tgdtor_param {
         const struct xt_target *target;
         void *targinfo;
+        u_int8_t family;
 };
 
 struct xt_match
@@ -393,9 +401,9 @@ extern void xt_unregister_match(struct xt_match *target);
 extern int xt_register_matches(struct xt_match *match, unsigned int n);
 extern void xt_unregister_matches(struct xt_match *match, unsigned int n);
 
-extern int xt_check_match(struct xt_mtchk_param *, u_int8_t family,
+extern int xt_check_match(struct xt_mtchk_param *,
                           unsigned int size, u_int8_t proto, bool inv_proto);
-extern int xt_check_target(struct xt_tgchk_param *, u_int8_t family,
+extern int xt_check_target(struct xt_tgchk_param *,
                            unsigned int size, u_int8_t proto, bool inv_proto);
 
 extern struct xt_table *xt_register_table(struct net *net,