[MPTCP] [PATCH 10/22] netfilter/ebtables: clean up compat {get, set}sockopt handling

[Christoph Hellwig <hch at lst.de>]

[-- Attachment #1: Type: text/plain, Size: 6724 bytes --]

Merge the native and compat {get,set}sockopt handlers using
in_compat_syscall().  Note that this required moving a fair
amout of code around to be done sanely.

Signed-off-by: Christoph Hellwig <hch(a)lst.de>
---
 net/bridge/netfilter/ebtables.c | 214 +++++++++++++++-----------------
 1 file changed, 98 insertions(+), 116 deletions(-)

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index c83ffe9121639c..fe13108af1f542 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1451,86 +1451,6 @@ static int copy_everything_to_user(struct ebt_table *t, void __user *user,
 	   ebt_entry_to_user, entries, tmp.entries);
 }
 
-static int do_ebt_set_ctl(struct sock *sk,
-	int cmd, void __user *user, unsigned int len)
-{
-	int ret;
-	struct net *net = sock_net(sk);
-
-	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
-		return -EPERM;
-
-	switch (cmd) {
-	case EBT_SO_SET_ENTRIES:
-		ret = do_replace(net, user, len);
-		break;
-	case EBT_SO_SET_COUNTERS:
-		ret = update_counters(net, user, len);
-		break;
-	default:
-		ret = -EINVAL;
-	}
-	return ret;
-}
-
-static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
-{
-	int ret;
-	struct ebt_replace tmp;
-	struct ebt_table *t;
-	struct net *net = sock_net(sk);
-
-	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
-		return -EPERM;
-
-	if (copy_from_user(&tmp, user, sizeof(tmp)))
-		return -EFAULT;
-
-	tmp.name[sizeof(tmp.name) - 1] = '\0';
-
-	t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
-	if (!t)
-		return ret;
-
-	switch (cmd) {
-	case EBT_SO_GET_INFO:
-	case EBT_SO_GET_INIT_INFO:
-		if (*len != sizeof(struct ebt_replace)) {
-			ret = -EINVAL;
-			mutex_unlock(&ebt_mutex);
-			break;
-		}
-		if (cmd == EBT_SO_GET_INFO) {
-			tmp.nentries = t->private->nentries;
-			tmp.entries_size = t->private->entries_size;
-			tmp.valid_hooks = t->valid_hooks;
-		} else {
-			tmp.nentries = t->table->nentries;
-			tmp.entries_size = t->table->entries_size;
-			tmp.valid_hooks = t->table->valid_hooks;
-		}
-		mutex_unlock(&ebt_mutex);
-		if (copy_to_user(user, &tmp, *len) != 0) {
-			ret = -EFAULT;
-			break;
-		}
-		ret = 0;
-		break;
-
-	case EBT_SO_GET_ENTRIES:
-	case EBT_SO_GET_INIT_ENTRIES:
-		ret = copy_everything_to_user(t, user, len, cmd);
-		mutex_unlock(&ebt_mutex);
-		break;
-
-	default:
-		mutex_unlock(&ebt_mutex);
-		ret = -EINVAL;
-	}
-
-	return ret;
-}
-
 #ifdef CONFIG_COMPAT
 /* 32 bit-userspace compatibility definitions. */
 struct compat_ebt_replace {
@@ -2314,28 +2234,6 @@ static int compat_update_counters(struct net *net, void __user *user,
 					hlp.num_counters, user, len);
 }
 
-static int compat_do_ebt_set_ctl(struct sock *sk,
-		int cmd, void __user *user, unsigned int len)
-{
-	int ret;
-	struct net *net = sock_net(sk);
-
-	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
-		return -EPERM;
-
-	switch (cmd) {
-	case EBT_SO_SET_ENTRIES:
-		ret = compat_do_replace(net, user, len);
-		break;
-	case EBT_SO_SET_COUNTERS:
-		ret = compat_update_counters(net, user, len);
-		break;
-	default:
-		ret = -EINVAL;
-	}
-	return ret;
-}
-
 static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
 		void __user *user, int *len)
 {
@@ -2344,14 +2242,6 @@ static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
 	struct ebt_table *t;
 	struct net *net = sock_net(sk);
 
-	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
-		return -EPERM;
-
-	/* try real handler in case userland supplied needed padding */
-	if ((cmd == EBT_SO_GET_INFO ||
-	     cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp))
-			return do_ebt_get_ctl(sk, cmd, user, len);
-
 	if (copy_from_user(&tmp, user, sizeof(tmp)))
 		return -EFAULT;
 
@@ -2413,20 +2303,112 @@ static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
 }
 #endif
 
+static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
+{
+	struct net *net = sock_net(sk);
+	struct ebt_replace tmp;
+	struct ebt_table *t;
+	int ret;
+
+	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+		return -EPERM;
+
+#ifdef CONFIG_COMPAT
+	/* try real handler in case userland supplied needed padding */
+	if (in_compat_syscall() &&
+	    ((cmd != EBT_SO_GET_INFO && cmd != EBT_SO_GET_INIT_INFO) ||
+	     *len != sizeof(tmp)))
+		return compat_do_ebt_get_ctl(sk, cmd, user, len);
+#endif
+
+	if (copy_from_user(&tmp, user, sizeof(tmp)))
+		return -EFAULT;
+
+	tmp.name[sizeof(tmp.name) - 1] = '\0';
+
+	t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
+	if (!t)
+		return ret;
+
+	switch (cmd) {
+	case EBT_SO_GET_INFO:
+	case EBT_SO_GET_INIT_INFO:
+		if (*len != sizeof(struct ebt_replace)) {
+			ret = -EINVAL;
+			mutex_unlock(&ebt_mutex);
+			break;
+		}
+		if (cmd == EBT_SO_GET_INFO) {
+			tmp.nentries = t->private->nentries;
+			tmp.entries_size = t->private->entries_size;
+			tmp.valid_hooks = t->valid_hooks;
+		} else {
+			tmp.nentries = t->table->nentries;
+			tmp.entries_size = t->table->entries_size;
+			tmp.valid_hooks = t->table->valid_hooks;
+		}
+		mutex_unlock(&ebt_mutex);
+		if (copy_to_user(user, &tmp, *len) != 0) {
+			ret = -EFAULT;
+			break;
+		}
+		ret = 0;
+		break;
+
+	case EBT_SO_GET_ENTRIES:
+	case EBT_SO_GET_INIT_ENTRIES:
+		ret = copy_everything_to_user(t, user, len, cmd);
+		mutex_unlock(&ebt_mutex);
+		break;
+
+	default:
+		mutex_unlock(&ebt_mutex);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int do_ebt_set_ctl(struct sock *sk, int cmd, void __user *user,
+		unsigned int len)
+{
+	struct net *net = sock_net(sk);
+	int ret;
+
+	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+		return -EPERM;
+
+	switch (cmd) {
+	case EBT_SO_SET_ENTRIES:
+#ifdef CONFIG_COMPAT
+		if (in_compat_syscall())
+			ret = compat_do_replace(net, user, len);
+		else
+#endif
+			ret = do_replace(net, user, len);
+		break;
+	case EBT_SO_SET_COUNTERS:
+#ifdef CONFIG_COMPAT
+		if (in_compat_syscall())
+			ret = compat_update_counters(net, user, len);
+		else
+#endif
+			ret = update_counters(net, user, len);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	return ret;
+}
+
 static struct nf_sockopt_ops ebt_sockopts = {
 	.pf		= PF_INET,
 	.set_optmin	= EBT_BASE_CTL,
 	.set_optmax	= EBT_SO_SET_MAX + 1,
 	.set		= do_ebt_set_ctl,
-#ifdef CONFIG_COMPAT
-	.compat_set	= compat_do_ebt_set_ctl,
-#endif
 	.get_optmin	= EBT_BASE_CTL,
 	.get_optmax	= EBT_SO_GET_MAX + 1,
 	.get		= do_ebt_get_ctl,
-#ifdef CONFIG_COMPAT
-	.compat_get	= compat_do_ebt_get_ctl,
-#endif
 	.owner		= THIS_MODULE,
 };
 
-- 
2.27.0