[PATCH 13/27] xtables: use match, target and data copy_to_user helpers in compat

[Pablo Neira Ayuso]

From: Willem de Bruijn <will...@google.com>

Convert compat to copying entries, matches and targets one by one,
using the xt_match_to_user and xt_target_to_user helper functions.

Signed-off-by: Willem de Bruijn <will...@google.com>
Signed-off-by: Pablo Neira Ayuso <pa...@netfilter.org>
---
 net/netfilter/x_tables.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index feccf527abdd..016db6be94b9 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -619,17 +619,14 @@ int xt_compat_match_to_user(const struct xt_entry_match 
*m,
        int off = xt_compat_match_offset(match);
        u_int16_t msize = m->u.user.match_size - off;
 
-       if (copy_to_user(cm, m, sizeof(*cm)) ||
-           put_user(msize, &cm->u.user.match_size) ||
-           copy_to_user(cm->u.user.name, m->u.kernel.match->name,
-                        strlen(m->u.kernel.match->name) + 1))
+       if (XT_OBJ_TO_USER(cm, m, match, msize))
                return -EFAULT;
 
        if (match->compat_to_user) {
                if (match->compat_to_user((void __user *)cm->data, m->data))
                        return -EFAULT;
        } else {
-               if (copy_to_user(cm->data, m->data, msize - sizeof(*cm)))
+               if (XT_DATA_TO_USER(cm, m, match, msize - sizeof(*cm)))
                        return -EFAULT;
        }
 
@@ -977,17 +974,14 @@ int xt_compat_target_to_user(const struct xt_entry_target 
*t,
        int off = xt_compat_target_offset(target);
        u_int16_t tsize = t->u.user.target_size - off;
 
-       if (copy_to_user(ct, t, sizeof(*ct)) ||
-           put_user(tsize, &ct->u.user.target_size) ||
-           copy_to_user(ct->u.user.name, t->u.kernel.target->name,
-                        strlen(t->u.kernel.target->name) + 1))
+       if (XT_OBJ_TO_USER(ct, t, target, tsize))
                return -EFAULT;
 
        if (target->compat_to_user) {
                if (target->compat_to_user((void __user *)ct->data, t->data))
                        return -EFAULT;
        } else {
-               if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct)))
+               if (XT_DATA_TO_USER(ct, t, target, tsize - sizeof(*ct)))
                        return -EFAULT;
        }
 
-- 
2.1.4