xtables: extend matches and targets with .usersize
In matches and targets that define a kernel-only tail to their
xt_match and xt_target data structs, add a field .usersize that
specifies up to where data is to be shared with userspace.
Performed a search for comment "Used internally by the kernel" to find
relevant matches and targets. Manually inspected the structs to derive
a valid offsetof.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/xt_cgroup.c b/net/netfilter/xt_cgroup.c
index a086a91..1db1ce5 100644
--- a/net/netfilter/xt_cgroup.c
+++ b/net/netfilter/xt_cgroup.c
@@ -122,6 +122,7 @@ static struct xt_match cgroup_mt_reg[] __read_mostly = {
.checkentry = cgroup_mt_check_v1,
.match = cgroup_mt_v1,
.matchsize = sizeof(struct xt_cgroup_info_v1),
+ .usersize = offsetof(struct xt_cgroup_info_v1, priv),
.destroy = cgroup_mt_destroy_v1,
.me = THIS_MODULE,
.hooks = (1 << NF_INET_LOCAL_OUT) |
