From a567dd6252263c8147b7269df5d03d9e31463e11 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 16 Aug 2013 15:25:00 -0400 Subject: macvtap: simplify usage of tap_features In macvtap, tap_features specific the features of that the user has specified via ioctl(). If we treat macvtap as a macvlan+tap then we could all the tap a pseudo-device and give it other features like SG and GSO. Then we can stop using the features of lower device (macvlan) when forwarding the traffic the tap. This solves the issue of possible checksum offload mismatch between tap feature and macvlan features. Signed-off-by: Vlad Yasevich Signed-off-by: David S. Miller --- drivers/net/macvtap.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'drivers/net/macvtap.c') diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index b51db2abfe44..448f8a505cd9 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -68,6 +68,8 @@ static const struct proto_ops macvtap_socket_ops; #define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \ NETIF_F_TSO6 | NETIF_F_UFO) #define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO) +#define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG) + /* * RCU usage: * The macvtap_queue and the macvlan_dev are loosely coupled, the @@ -278,7 +280,8 @@ static int macvtap_forward(struct net_device *dev, struct sk_buff *skb) { struct macvlan_dev *vlan = netdev_priv(dev); struct macvtap_queue *q = macvtap_get_queue(dev, skb); - netdev_features_t features; + netdev_features_t features = TAP_FEATURES; + if (!q) goto drop; @@ -289,7 +292,7 @@ static int macvtap_forward(struct net_device *dev, struct sk_buff *skb) /* Apply the forward feature mask so that we perform segmentation * according to users wishes. */ - features = netif_skb_features(skb) & vlan->tap_features; + features |= vlan->tap_features; if (netif_needs_gso(skb, features)) { struct sk_buff *segs = __skb_gso_segment(skb, features, false); @@ -1064,8 +1067,7 @@ static int set_offload(struct macvtap_queue *q, unsigned long arg) /* tap_features are the same as features on tun/tap and * reflect user expectations. */ - vlan->tap_features = vlan->dev->features & - (feature_mask | ~TUN_OFFLOADS); + vlan->tap_features = feature_mask; vlan->set_features = features; netdev_update_features(vlan->dev); -- cgit v1.2.1 From e558b0188bb7e35ffc4d35253c6b9ea491f3b996 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 16 Aug 2013 15:25:01 -0400 Subject: macvtap: Correctly set tap features when IFF_VNET_HDR is disabled. When the user turns off IFF_VNET_HDR flag, attempts to change offload features via TUNSETOFFLOAD do not work. This could cause GSO packets to be delivered to the user when the user is not prepared to handle them. To solve, allow processing of TUNSETOFFLOAD when IFF_VNET_HDR is disabled. Signed-off-by: Vlad Yasevich Signed-off-by: David S. Miller --- drivers/net/macvtap.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'drivers/net/macvtap.c') diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index 448f8a505cd9..4acfbce63a7d 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -1163,10 +1163,6 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd, TUN_F_TSO_ECN | TUN_F_UFO)) return -EINVAL; - /* TODO: only accept frames with the features that - got enabled for forwarded frames */ - if (!(q->flags & IFF_VNET_HDR)) - return -EINVAL; rtnl_lock(); ret = set_offload(q, arg); rtnl_unlock(); -- cgit v1.2.1 From e5733321d5a94cc9a202ea85c4aabe09571217e6 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 16 Aug 2013 15:25:02 -0400 Subject: macvtap: Ignore tap features when VNET_HDR is off When the user turns off VNET_HDR support on the macvtap device, there is no way to provide any offload information to the user. So, it's safer to ignore offload setting then depend on the user setting them correctly. Signed-off-by: Vlad Yasevich Signed-off-by: David S. Miller --- drivers/net/macvtap.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/net/macvtap.c') diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index 4acfbce63a7d..ea53abb20988 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -290,9 +290,11 @@ static int macvtap_forward(struct net_device *dev, struct sk_buff *skb) skb->dev = dev; /* Apply the forward feature mask so that we perform segmentation - * according to users wishes. + * according to users wishes. This only works if VNET_HDR is + * enabled. */ - features |= vlan->tap_features; + if (q->flags & IFF_VNET_HDR) + features |= vlan->tap_features; if (netif_needs_gso(skb, features)) { struct sk_buff *segs = __skb_gso_segment(skb, features, false); -- cgit v1.2.1