[PATCH net-next] ethtool: ioctl: improve error checking for set_wol

From: Justin Chen <justin.chen@broadcom.com>
To: netdev@vger.kernel.org
Cc: simon.horman@corigine.com, Justin Chen <justin.chen@broadcom.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Daniil Tatianin <d-tatianin@yandex-team.ru>,
	Marco Bonelli <marco@mebeim.net>, Gal Pressman <gal@nvidia.com>,
	Jiri Pirko <jiri@resnulli.us>,
	Sean Anderson <sean.anderson@seco.com>,
	Vincent Mailhol <mailhol.vincent@wanadoo.fr>,
	Kuniyuki Iwashima <kuniyu@amazon.com>,
	linux-kernel@vger.kernel.org (open list)
Subject: [PATCH net-next] ethtool: ioctl: improve error checking for set_wol
Date: Mon,  5 Jun 2023 11:46:16 -0700	[thread overview]
Message-ID: <1685990778-34039-1-git-send-email-justin.chen@broadcom.com> (raw)

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The netlink version of set_wol checks for not supported wolopts and avoids
setting wol when the correct wolopt is already set. If we do the same with
the ioctl version then we can remove these checks from the driver layer.

Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Justin Chen <justin.chen@broadcom.com>
---
 net/ethtool/ioctl.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 6bb778e10461..80f456f83db0 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1436,15 +1436,25 @@ static int ethtool_get_wol(struct net_device *dev, char __user *useraddr)
 
 static int ethtool_set_wol(struct net_device *dev, char __user *useraddr)
 {
-	struct ethtool_wolinfo wol;
+	struct ethtool_wolinfo wol, cur_wol;
 	int ret;
 
-	if (!dev->ethtool_ops->set_wol)
+	if (!dev->ethtool_ops->get_wol || !dev->ethtool_ops->set_wol)
 		return -EOPNOTSUPP;
 
+	memset(&cur_wol, 0, sizeof(struct ethtool_wolinfo));
+	cur_wol.cmd = ETHTOOL_GWOL;
+	dev->ethtool_ops->get_wol(dev, &cur_wol);
+
 	if (copy_from_user(&wol, useraddr, sizeof(wol)))
 		return -EFAULT;
 
+	if (wol.wolopts & ~cur_wol.supported)
+		return -EOPNOTSUPP;
+
+	if (wol.wolopts == cur_wol.wolopts)
+		return 0;
+
 	ret = dev->ethtool_ops->set_wol(dev, &wol);
 	if (ret)
 		return ret;
-- 
2.7.4


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