netfilter: x_tables: introduce and use xt_copy_counters_from_user

[karo-tx-linux.git] / net / ipv4 / netfilter / arp_tables.c

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 5158846b55ef00fdcec02b78c764c71f9ec1e6c9..6e3e0e8b1ce3254a96220a82f40dc2a36703cc6f 100644 (file)
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1130,55 +1130,17 @@ static int do_add_counters(struct net *net, const void __user *user,
        unsigned int i;
        struct xt_counters_info tmp;
        struct xt_counters *paddc;
-       unsigned int num_counters;
-       const char *name;
-       int size;
-       void *ptmp;
        struct xt_table *t;
        const struct xt_table_info *private;
        int ret = 0;
        struct arpt_entry *iter;
        unsigned int addend;
-#ifdef CONFIG_COMPAT
-       struct compat_xt_counters_info compat_tmp;
-
-       if (compat) {
-               ptmp = &compat_tmp;
-               size = sizeof(struct compat_xt_counters_info);
-       } else
-#endif
-       {
-               ptmp = &tmp;
-               size = sizeof(struct xt_counters_info);
-       }
 
-       if (copy_from_user(ptmp, user, size) != 0)
-               return -EFAULT;
-
-#ifdef CONFIG_COMPAT
-       if (compat) {
-               num_counters = compat_tmp.num_counters;
-               name = compat_tmp.name;
-       } else
-#endif
-       {
-               num_counters = tmp.num_counters;
-               name = tmp.name;
-       }
-
-       if (len != size + num_counters * sizeof(struct xt_counters))
-               return -EINVAL;
-
-       paddc = vmalloc(len - size);
-       if (!paddc)
-               return -ENOMEM;
-
-       if (copy_from_user(paddc, user + size, len - size) != 0) {
-               ret = -EFAULT;
-               goto free;
-       }
+       paddc = xt_copy_counters_from_user(user, len, &tmp, compat);
+       if (IS_ERR(paddc))
+               return PTR_ERR(paddc);
 
-       t = xt_find_table_lock(net, NFPROTO_ARP, name);
+       t = xt_find_table_lock(net, NFPROTO_ARP, tmp.name);
        if (IS_ERR_OR_NULL(t)) {
                ret = t ? PTR_ERR(t) : -ENOENT;
                goto free;
@@ -1186,7 +1148,7 @@ static int do_add_counters(struct net *net, const void __user *user,
 
        local_bh_disable();
        private = t->private;
-       if (private->number != num_counters) {
+       if (private->number != tmp.num_counters) {
                ret = -EINVAL;
                goto unlock_up_free;
        }