Subject: [PATCH net-next v2 6/9] net: use core MTU range checking in virt drivers

From: Jarod Wilson <[email-masked]>
Date: Thu, 20 Oct 2016 13:55:21 -0400

hyperv_net:
- set min/max_mtu, per Haiyang, after rndis_filter_device_add

virtio_net:
- set min/max_mtu
- remove virtnet_change_mtu

vmxnet3:
- set min/max_mtu

xen-netback:
- min_mtu = 0, max_mtu = 65517

xen-netfront:
- min_mtu = 0, max_mtu = 65535

unisys/visor:
- clean up defines a little to not clash with network core or add
  redundat definitions

CC: [email-masked]
CC: [email-masked]
CC: "K. Y. Srinivasan" <[email-masked]>
CC: Haiyang Zhang <[email-masked]>
CC: "Michael S. Tsirkin" <[email-masked]>
CC: Shrikrishna Khare <[email-masked]>
CC: "VMware, Inc." <[email-masked]>
CC: Wei Liu <[email-masked]>
CC: Paul Durrant <[email-masked]>
CC: David Kershner <[email-masked]>
Signed-off-by: Jarod Wilson <[email-masked]>
---
 drivers/net/hyperv/hyperv_net.h                 |  4 ++--
 drivers/net/hyperv/netvsc_drv.c                 | 14 +++++++-------
 drivers/net/virtio_net.c                        | 23 ++++++++++-------------
 drivers/net/vmxnet3/vmxnet3_drv.c               |  7 ++++---
 drivers/net/xen-netback/interface.c             |  5 ++++-
 drivers/net/xen-netfront.c                      |  2 ++
 drivers/staging/unisys/include/iochannel.h      | 10 ++++------
 drivers/staging/unisys/visornic/visornic_main.c |  4 ++--
 8 files changed, 35 insertions(+), 34 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index f4fbcb5..3958ada 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -606,8 +606,8 @@ struct nvsp_message {
 } __packed;

-#define NETVSC_MTU 65536
-#define NETVSC_MTU_MIN 68
+#define NETVSC_MTU 65535
+#define NETVSC_MTU_MIN ETH_MIN_MTU
 
 #define NETVSC_RECEIVE_BUFFER_SIZE		(1024*1024*16)	/* 16MB */
 #define NETVSC_RECEIVE_BUFFER_SIZE_LEGACY	(1024*1024*15)  /* 15MB */
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index f0919bd..3b28cf1 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -872,19 +872,12 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu)
 	struct netvsc_device *nvdev = ndevctx->nvdev;
 	struct hv_device *hdev = ndevctx->device_ctx;
 	struct netvsc_device_info device_info;
-	int limit = ETH_DATA_LEN;
 	u32 num_chn;
 	int ret = 0;
 
 	if (ndevctx->start_remove || !nvdev || nvdev->destroy)
 		return -ENODEV;
 
-	if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
-		limit = NETVSC_MTU - ETH_HLEN;
-
-	if (mtu < NETVSC_MTU_MIN || mtu > limit)
-		return -EINVAL;
-
 	ret = netvsc_close(ndev);
 	if (ret)
 		goto out;
@@ -1402,6 +1395,13 @@ static int netvsc_probe(struct hv_device *dev,
 	netif_set_real_num_tx_queues(net, nvdev->num_chn);
 	netif_set_real_num_rx_queues(net, nvdev->num_chn);
 
+	/* MTU range: 68 - 1500 or 65521 */
+	net->min_mtu = NETVSC_MTU_MIN;
+	if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
+		net->max_mtu = NETVSC_MTU - ETH_HLEN;
+	else
+		net->max_mtu = ETH_DATA_LEN;
+
 	ret = register_netdev(net);
 	if (ret != 0) {
 		pr_err("Unable to register netdev.\n");
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index fad84f3..720809f 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1419,17 +1419,6 @@ static const struct ethtool_ops virtnet_ethtool_ops = {
 	.set_settings = virtnet_set_settings,
 };
 
-#define MIN_MTU 68
-#define MAX_MTU 65535
-
-static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
-{
-	if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
-		return -EINVAL;
-	dev->mtu = new_mtu;
-	return 0;
-}
-
 static const struct net_device_ops virtnet_netdev = {
 	.ndo_open            = virtnet_open,
 	.ndo_stop   	     = virtnet_close,
@@ -1437,7 +1426,6 @@ static const struct net_device_ops virtnet_netdev = {
 	.ndo_validate_addr   = eth_validate_addr,
 	.ndo_set_mac_address = virtnet_set_mac_address,
 	.ndo_set_rx_mode     = virtnet_set_rx_mode,
-	.ndo_change_mtu	     = virtnet_change_mtu,
 	.ndo_get_stats64     = virtnet_stats,
 	.ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
 	.ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
@@ -1748,6 +1736,9 @@ static bool virtnet_validate_features(struct virtio_device *vdev)
 	return true;
 }
 
+#define MIN_MTU ETH_MIN_MTU
+#define MAX_MTU ETH_MAX_MTU
+
 static int virtnet_probe(struct virtio_device *vdev)
 {
 	int i, err;
@@ -1821,6 +1812,10 @@ static int virtnet_probe(struct virtio_device *vdev)
 
 	dev->vlan_features = dev->features;
 
+	/* MTU range: 68 - 65535 */
+	dev->min_mtu = MIN_MTU;
+	dev->max_mtu = MAX_MTU;
+
 	/* Configuration may specify what MAC to use.  Otherwise random. */
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
 		virtio_cread_bytes(vdev,
@@ -1875,8 +1870,10 @@ static int virtnet_probe(struct virtio_device *vdev)
 		mtu = virtio_cread16(vdev,
 				     offsetof(struct virtio_net_config,
 					      mtu));
-		if (virtnet_change_mtu(dev, mtu))
+		if (mtu < dev->min_mtu || mtu > dev->max_mtu)
 			__virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
+		else
+			dev->mtu = mtu;
 	}
 
 	if (vi->any_header_sg)
diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c
index b5554f2..0c36de1 100644
--- a/drivers/net/vmxnet3/vmxnet3_drv.c
+++ b/drivers/net/vmxnet3/vmxnet3_drv.c
@@ -2969,9 +2969,6 @@ vmxnet3_change_mtu(struct net_device *netdev, int new_mtu)
 	struct vmxnet3_adapter *adapter = netdev_priv(netdev);
 	int err = 0;
 
-	if (new_mtu < VMXNET3_MIN_MTU || new_mtu > VMXNET3_MAX_MTU)
-		return -EINVAL;
-
 	netdev->mtu = new_mtu;
 
 	/*
@@ -3428,6 +3425,10 @@ vmxnet3_probe_device(struct pci_dev *pdev,
 	vmxnet3_set_ethtool_ops(netdev);
 	netdev->watchdog_timeo = 5 * HZ;
 
+	/* MTU range: 60 - 9000 */
+	netdev->min_mtu = VMXNET3_MIN_MTU;
+	netdev->max_mtu = VMXNET3_MAX_MTU;
+
 	INIT_WORK(&adapter->work, vmxnet3_reset_work);
 	set_bit(VMXNET3_STATE_BIT_QUIESCED, &adapter->state);
 
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index 74dc2bf..e30ffd2 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -302,7 +302,7 @@ static int xenvif_close(struct net_device *dev)
 static int xenvif_change_mtu(struct net_device *dev, int mtu)
 {
 	struct xenvif *vif = netdev_priv(dev);
-	int max = vif->can_sg ? 65535 - VLAN_ETH_HLEN : ETH_DATA_LEN;
+	int max = vif->can_sg ? ETH_MAX_MTU - VLAN_ETH_HLEN : ETH_DATA_LEN;
 
 	if (mtu > max)
 		return -EINVAL;
@@ -471,6 +471,9 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
 
 	dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
 
+	dev->min_mtu = 0;
+	dev->max_mtu = ETH_MAX_MTU - VLAN_ETH_HLEN;
+
 	/*
 	 * Initialise a dummy MAC address. We choose the numerically
 	 * largest non-broadcast address to prevent the address getting
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index e17879d..7d616b0 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1329,6 +1329,8 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev)
 	netdev->features |= netdev->hw_features;
 
 	netdev->ethtool_ops = &xennet_ethtool_ops;
+	netdev->min_mtu = 0;
+	netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
 	SET_NETDEV_DEV(netdev, &dev->dev);
 
 	np->netdev = netdev;
diff --git a/drivers/staging/unisys/include/iochannel.h b/drivers/staging/unisys/include/iochannel.h
index cba4433..9081b3f 100644
--- a/drivers/staging/unisys/include/iochannel.h
+++ b/drivers/staging/unisys/include/iochannel.h
@@ -113,12 +113,10 @@ enum net_types {
 
 };
 
-#define		ETH_HEADER_SIZE 14	/* size of ethernet header */
-
 #define		ETH_MIN_DATA_SIZE 46	/* minimum eth data size */
-#define		ETH_MIN_PACKET_SIZE (ETH_HEADER_SIZE + ETH_MIN_DATA_SIZE)
+#define		ETH_MIN_PACKET_SIZE (ETH_HLEN + ETH_MIN_DATA_SIZE)
 
-#define		ETH_MAX_MTU 16384	/* maximum data size */
+#define		VISOR_ETH_MAX_MTU 16384	/* maximum data size */
 
 #ifndef MAX_MACADDR_LEN
 #define MAX_MACADDR_LEN 6	/* number of bytes in MAC address */
@@ -288,7 +286,7 @@ struct net_pkt_xmt {
 	int len;	/* full length of data in the packet */
 	int num_frags;	/* number of fragments in frags containing data */
 	struct phys_info frags[MAX_PHYS_INFO];	/* physical page information */
-	char ethhdr[ETH_HEADER_SIZE];	/* the ethernet header  */
+	char ethhdr[ETH_HLEN];	/* the ethernet header  */
 	struct {
 		/* these are needed for csum at uisnic end */
 		u8 valid;	/* 1 = struct is valid - else ignore */
@@ -323,7 +321,7 @@ struct net_pkt_xmtdone {
  */
 #define RCVPOST_BUF_SIZE 4032
 #define MAX_NET_RCV_CHAIN \
-	((ETH_MAX_MTU + ETH_HEADER_SIZE + RCVPOST_BUF_SIZE - 1) \
+	((VISOR_ETH_MAX_MTU + ETH_HLEN + RCVPOST_BUF_SIZE - 1) \
 	/ RCVPOST_BUF_SIZE)
 
 struct net_pkt_rcvpost {
diff --git a/drivers/staging/unisys/visornic/visornic_main.c b/drivers/staging/unisys/visornic/visornic_main.c
index 1367007..f8a584b 100644
--- a/drivers/staging/unisys/visornic/visornic_main.c
+++ b/drivers/staging/unisys/visornic/visornic_main.c
@@ -791,7 +791,7 @@ visornic_xmit(struct sk_buff *skb, struct net_device *netdev)
 	 * pointing to
 	 */
 	firstfraglen = skb->len - skb->data_len;
-	if (firstfraglen < ETH_HEADER_SIZE) {
+	if (firstfraglen < ETH_HLEN) {
 		spin_unlock_irqrestore(&devdata->priv_lock, flags);
 		devdata->busy_cnt++;
 		dev_err(&netdev->dev,
@@ -864,7 +864,7 @@ visornic_xmit(struct sk_buff *skb, struct net_device *netdev)
 	/* copy ethernet header from first frag into ocmdrsp
 	 * - everything else will be pass in frags & DMA'ed
 	 */
-	memcpy(cmdrsp->net.xmt.ethhdr, skb->data, ETH_HEADER_SIZE);
+	memcpy(cmdrsp->net.xmt.ethhdr, skb->data, ETH_HLEN);
 	/* copy frags info - from skb->data we need to only provide access
 	 * beyond eth header
 	 */
-- 
2.10.0