[NETFILTER]: xt_limit: add compat conversion functions

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 49 insertions, 0 deletions

diff --git a/net/netfilter/xt_limit.c b/net/netfilter/xt_limit.c
index 8bfcbdfa8783..fda7b7dec27d 100644
--- a/net/netfilter/xt_limit.c
+++ b/net/netfilter/xt_limit.c
@@ -135,6 +135,50 @@ ipt_limit_checkentry(const char *tablename,
         return 1;
 }
 
+#ifdef CONFIG_COMPAT
+struct compat_xt_rateinfo {
+        u_int32_t avg;
+        u_int32_t burst;
+
+        compat_ulong_t prev;
+        u_int32_t credit;
+        u_int32_t credit_cap, cost;
+
+        u_int32_t master;
+};
+
+/* To keep the full "prev" timestamp, the upper 32 bits are stored in the
+ * master pointer, which does not need to be preserved. */
+static void compat_from_user(void *dst, void *src)
+{
+        struct compat_xt_rateinfo *cm = src;
+        struct xt_rateinfo m = {
+                .avg            = cm->avg,
+                .burst          = cm->burst,
+                .prev           = cm->prev | (unsigned long)cm->master << 32,
+                .credit         = cm->credit,
+                .credit_cap     = cm->credit_cap,
+                .cost           = cm->cost,
+        };
+        memcpy(dst, &m, sizeof(m));
+}
+
+static int compat_to_user(void __user *dst, void *src)
+{
+        struct xt_rateinfo *m = src;
+        struct compat_xt_rateinfo cm = {
+                .avg            = m->avg,
+                .burst          = m->burst,
+                .prev           = m->prev,
+                .credit         = m->credit,
+                .credit_cap     = m->credit_cap,
+                .cost           = m->cost,
+                .master         = m->prev >> 32,
+        };
+        return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0;
+}
+#endif /* CONFIG_COMPAT */
+
 static struct xt_match xt_limit_match[] = {
         {
                 .name           = "limit",
@@ -142,6 +186,11 @@ static struct xt_match xt_limit_match[] = {
                 .checkentry     = ipt_limit_checkentry,
                 .match          = ipt_limit_match,
                 .matchsize      = sizeof(struct xt_rateinfo),
+#ifdef CONFIG_COMPAT
+                .compatsize     = sizeof(struct compat_xt_rateinfo),
+                .compat_from_user = compat_from_user,
+                .compat_to_user = compat_to_user,
+#endif
                 .me             = THIS_MODULE,
         },
         {