ipvlan: remove excessive packet scrubbing

Mahesh Bandewar · davem330 · commit c0d451c86ca2 · 2017-12-15T11:36:53.000-05:00
IPvlan currently scrubs packets at every location where packets may be crossing namespace boundary. Though this is desirable, currently IPvlan does it more than necessary. e.g. packets that are going to take dev_forward_skb() path will get scrubbed so no point in scrubbing them before forwarding. Another side-effect of scrubbing is that pkt-type gets set to PACKET_HOST which overrides what was already been set by the earlier path making erroneous delivery of the packets. Also scrubbing packets just before calling dev_queue_xmit() has detrimental effects since packets lose skb->sk and because of that miss prio updates, incorrect socket back-pressure and would even break TSQ. Fixes: b93dd49 ('ipvlan: Scrub skb before crossing the namespace boundary') Signed-off-by: Mahesh Bandewar <maheshb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ipvlan/ipvlan_core.c b/drivers/net/ipvlan/ipvlan_core.c
@@ -315,13 +315,13 @@ static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff **pskb,
 
 		*pskb = skb;
 	}
-	ipvlan_skb_crossing_ns(skb, dev);
 
 	if (local) {
 		skb->pkt_type = PACKET_HOST;
 		if (dev_forward_skb(ipvlan->dev, skb) == NET_RX_SUCCESS)
 			success = true;
 	} else {
+		skb->dev = dev;
 		ret = RX_HANDLER_ANOTHER;
 		success = true;
 	}
@@ -586,7 +586,7 @@ static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
 		return NET_XMIT_SUCCESS;
 	}
 
-	ipvlan_skb_crossing_ns(skb, ipvlan->phy_dev);
+	skb->dev = ipvlan->phy_dev;
 	return dev_queue_xmit(skb);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -315,13 +315,13 @@ static int ipvlan_rcv_frame(struct ipvl_addr addr, struct sk_buff *pskb,`
`315`	`315`
`316`	`316`	`*pskb = skb;`
`317`	`317`	`}`
`318`		`- ipvlan_skb_crossing_ns(skb, dev);`
`319`	`318`
`320`	`319`	`if (local) {`
`321`	`320`	`skb->pkt_type = PACKET_HOST;`
`322`	`321`	`if (dev_forward_skb(ipvlan->dev, skb) == NET_RX_SUCCESS)`
`323`	`322`	`success = true;`
`324`	`323`	`} else {`
	`324`	`+ skb->dev = dev;`
`325`	`325`	`ret = RX_HANDLER_ANOTHER;`
`326`	`326`	`success = true;`
`327`	`327`	`}`
`@@ -586,7 +586,7 @@ static int ipvlan_xmit_mode_l2(struct sk_buff skb, struct net_device dev)`
`586`	`586`	`return NET_XMIT_SUCCESS;`
`587`	`587`	`}`
`588`	`588`
`589`		`- ipvlan_skb_crossing_ns(skb, ipvlan->phy_dev);`
	`589`	`+ skb->dev = ipvlan->phy_dev;`
`590`	`590`	`return dev_queue_xmit(skb);`
`591`	`591`	`}`
`592`	`592`