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Commit 8a83a00b authored by Arnd Bergmann's avatar Arnd Bergmann Committed by David S. Miller
Browse files

net: maintain namespace isolation between vlan and real device 



In the vlan and macvlan drivers, the start_xmit function forwards
data to the dev_queue_xmit function for another device, which may
potentially belong to a different namespace.

To make sure that classification stays within a single namespace,
this resets the potentially critical fields.

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6884b348

drivers/net/macvlan.c

+1 −1
Original line number Diff line number Diff line
@@ -269,7 +269,7 @@ static int macvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev) 
	}



xmit_world:

	skb->dev = vlan->lowerdev;

	skb_set_dev(skb, vlan->lowerdev);

	return dev_queue_xmit(skb);

}

include/linux/netdevice.h

+9 −0
Original line number Diff line number Diff line
@@ -1004,6 +1004,15 @@ static inline bool netdev_uses_dsa_tags(struct net_device *dev) 
	return 0;

}



#ifndef CONFIG_NET_NS

static inline void skb_set_dev(struct sk_buff *skb, struct net_device *dev)

{

	skb->dev = dev;

}

#else /* CONFIG_NET_NS */

void skb_set_dev(struct sk_buff *skb, struct net_device *dev);

#endif



static inline bool netdev_uses_trailer_tags(struct net_device *dev)

{

#ifdef CONFIG_NET_DSA_TAG_TRAILER

net/8021q/vlan_dev.c

+1 −1
Original line number Diff line number Diff line
@@ -322,7 +322,7 @@ static netdev_tx_t vlan_dev_hard_start_xmit(struct sk_buff *skb, 
	}





	skb->dev = vlan_dev_info(dev)->real_dev;

	skb_set_dev(skb, vlan_dev_info(dev)->real_dev);

	len = skb->len;

	ret = dev_queue_xmit(skb);

net/core/dev.c

+31 −4
Original line number Diff line number Diff line
@@ -1448,13 +1448,10 @@ int dev_forward_skb(struct net_device *dev, struct sk_buff *skb) 
	if (skb->len > (dev->mtu + dev->hard_header_len))

		return NET_RX_DROP;



	skb_dst_drop(skb);

	skb_set_dev(skb, dev);

	skb->tstamp.tv64 = 0;

	skb->pkt_type = PACKET_HOST;

	skb->protocol = eth_type_trans(skb, dev);

	skb->mark = 0;

	secpath_reset(skb);

	nf_reset(skb);

	return netif_rx(skb);

}

EXPORT_SYMBOL_GPL(dev_forward_skb);
@@ -1614,6 +1611,36 @@ static bool dev_can_checksum(struct net_device *dev, struct sk_buff *skb) 
	return false;

}



/**

 * skb_dev_set -- assign a new device to a buffer

 * @skb: buffer for the new device

 * @dev: network device

 *

 * If an skb is owned by a device already, we have to reset

 * all data private to the namespace a device belongs to

 * before assigning it a new device.

 */

#ifdef CONFIG_NET_NS

void skb_set_dev(struct sk_buff *skb, struct net_device *dev)

{

	skb_dst_drop(skb);

	if (skb->dev && !net_eq(dev_net(skb->dev), dev_net(dev))) {

		secpath_reset(skb);

		nf_reset(skb);

		skb_init_secmark(skb);

		skb->mark = 0;

		skb->priority = 0;

		skb->nf_trace = 0;

		skb->ipvs_property = 0;

#ifdef CONFIG_NET_SCHED

		skb->tc_index = 0;

#endif

	}

	skb->dev = dev;

}

EXPORT_SYMBOL(skb_set_dev);

#endif /* CONFIG_NET_NS */



/*

 * Invalidate hardware checksum when packet is to be mangled, and

 * complete checksum manually on outgoing path.