[3.8.y.z extended stable] Patch "net: core: introduce netif_skb_dev_features" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    net: core: introduce netif_skb_dev_features

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.21.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From ff10e6e453189a05b16f1322a89b9752239166ac Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw at strlen.de>
Date: Sat, 22 Feb 2014 10:30:18 +0100
Subject: net: core: introduce netif_skb_dev_features

commit d206940319c41df4299db75ed56142177bb2e5f6 upstream.

Will be used by upcoming ipv4 forward path change that needs to
determine feature mask using skb->dst->dev instead of skb->dev.

Signed-off-by: Florian Westphal <fw at strlen.de>
Signed-off-by: David S. Miller <davem at davemloft.net>
[ kamal: backport to 3.8 (context) ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 include/linux/netdevice.h |  7 ++++++-
 net/core/dev.c            | 27 ++++++++++++++++-----------
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 0cabad8..48b1504 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2679,7 +2679,12 @@ void netdev_change_features(struct net_device *dev);
 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
 					struct net_device *dev);

-netdev_features_t netif_skb_features(struct sk_buff *skb);
+netdev_features_t netif_skb_dev_features(struct sk_buff *skb,
+					 const struct net_device *dev);
+static inline netdev_features_t netif_skb_features(struct sk_buff *skb)
+{
+	return netif_skb_dev_features(skb, skb->dev);
+}

 static inline bool net_gso_ok(netdev_features_t features, int gso_type)
 {
diff --git a/net/core/dev.c b/net/core/dev.c
index 4fe7689..59a5ce7 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2153,7 +2153,7 @@ EXPORT_SYMBOL(netdev_rx_csum_fault);
  * 2. No high memory really exists on this machine.
  */

-static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
+static int illegal_highdma(const struct net_device *dev, struct sk_buff *skb)
 {
 #ifdef CONFIG_HIGHMEM
 	int i;
@@ -2244,45 +2244,50 @@ static bool can_checksum_protocol(netdev_features_t features, __be16 protocol)
 }

 static netdev_features_t harmonize_features(struct sk_buff *skb,
-	__be16 protocol, netdev_features_t features)
+					    __be16 protocol,
+					    const struct net_device *dev,
+					    netdev_features_t features)
 {
 	if (skb->ip_summed != CHECKSUM_NONE &&
 	    !can_checksum_protocol(features, protocol)) {
 		features &= ~NETIF_F_ALL_CSUM;
 		features &= ~NETIF_F_SG;
-	} else if (illegal_highdma(skb->dev, skb)) {
+	} else if (illegal_highdma(dev, skb)) {
 		features &= ~NETIF_F_SG;
 	}

 	return features;
 }

-netdev_features_t netif_skb_features(struct sk_buff *skb)
+netdev_features_t netif_skb_dev_features(struct sk_buff *skb,
+					 const struct net_device *dev)
 {
 	__be16 protocol = skb->protocol;
-	netdev_features_t features = skb->dev->features;
+	netdev_features_t features = dev->features;

-	if (skb_shinfo(skb)->gso_segs > skb->dev->gso_max_segs)
+	if (skb_shinfo(skb)->gso_segs > dev->gso_max_segs)
 		features &= ~NETIF_F_GSO_MASK;

 	if (protocol == htons(ETH_P_8021Q)) {
 		struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
 		protocol = veh->h_vlan_encapsulated_proto;
 	} else if (!vlan_tx_tag_present(skb)) {
-		return harmonize_features(skb, protocol, features);
+		return harmonize_features(skb, protocol, dev, features);
 	}

-	features &= (skb->dev->vlan_features | NETIF_F_HW_VLAN_TX);
+	features &= (dev->vlan_features | NETIF_F_HW_VLAN_TX);

 	if (protocol != htons(ETH_P_8021Q)) {
-		return harmonize_features(skb, protocol, features);
+		return harmonize_features(skb, protocol, dev, features);
 	} else {
 		features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
 				NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_TX;
-		return harmonize_features(skb, protocol, features);
+		return harmonize_features(skb, protocol, dev, features);
 	}
+
+	return harmonize_features(skb, protocol, dev, features);
 }
-EXPORT_SYMBOL(netif_skb_features);
+EXPORT_SYMBOL(netif_skb_dev_features);

 /*
  * Returns true if either:
--
1.8.3.2