[ovs-dev,2/8] datapath: Fix pop_vlan action for double tagged frames

Message ID 1518650290-31536-3-git-send-email-gvrose8192@gmail.com
State Accepted
Headers show
Series
  • Linux upstream kernel backports and updates
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Commit Message

Gregory Rose Feb. 14, 2018, 11:18 p.m.
From: Eric Garver <e@erig.me>

Upstream commit:
    commit c48e74736fccf25fb32bb015426359e1c2016e3b
    Author: Eric Garver <e@erig.me>
    Date:   Wed Dec 20 15:09:22 2017 -0500

    openvswitch: Fix pop_vlan action for double tagged frames

    skb_vlan_pop() expects skb->protocol to be a valid TPID for double
    tagged frames. So set skb->protocol to the TPID and let skb_vlan_pop()
    shift the true ethertype into position for us.

    Fixes: 5108bbaddc37 ("openvswitch: add processing of L3 packets")
    Signed-off-by: Eric Garver <e@erig.me>
    Reviewed-by: Jiri Benc <jbenc@redhat.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>

Cc: Eric Garver <e@erig.me>
Fixes: a27c454ee0 ("datapath: add processing of L3 packets")
Signed-off-by: Greg Rose <gvrose8192@gmail.com>
---
 datapath/flow.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

Patch

diff --git a/datapath/flow.c b/datapath/flow.c
index e345ec9..fadc074 100644
--- a/datapath/flow.c
+++ b/datapath/flow.c
@@ -584,6 +584,7 @@  static int key_extract(struct sk_buff *skb, struct sw_flow_key *key)
 			return -EINVAL;
 
 		skb_reset_network_header(skb);
+		key->eth.type = skb->protocol;
 	} else {
 		eth = eth_hdr(skb);
 		ether_addr_copy(key->eth.src, eth->h_source);
@@ -597,16 +598,24 @@  static int key_extract(struct sk_buff *skb, struct sw_flow_key *key)
 		if (unlikely(parse_vlan(skb, key)))
 			return -ENOMEM;
 
-		skb->protocol = parse_ethertype(skb);
-		if (unlikely(skb->protocol == htons(0)))
+		key->eth.type = parse_ethertype(skb);
+		if (unlikely(key->eth.type == htons(0)))
 			return -ENOMEM;
 
+		/* Multiple tagged packets need to retain TPID to satisfy
+		 * skb_vlan_pop(), which will later shift the ethertype into
+		 * skb->protocol.
+		 */
+		if (key->eth.cvlan.tci & htons(VLAN_TAG_PRESENT))
+			skb->protocol = key->eth.cvlan.tpid;
+		else
+			skb->protocol = key->eth.type;
+
 		skb_reset_network_header(skb);
 		__skb_push(skb, skb->data - skb_mac_header(skb));
 	}
 
 	skb_reset_mac_len(skb);
-	key->eth.type = skb->protocol;
 
 	/* Network layer. */
 	if (key->eth.type == htons(ETH_P_IP)) {