[PATCH net-next 1/2] openvswitch: remove nonreachable code in vlan parsing
flat view
STALE3665d
From: Jiri Benc <hidden>
Date: 2016-10-04 12:30:17
Subsystem:
networking [general], openvswitch, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Aaron Conole, Eelco Chaudron, Ilya Maximets, Linus Torvalds
Revision v1 of 2 in this series.
Revisions (2)
- v1 current
- v1
It can never happen that there's a vlan tag in the packet but not in
skb->vlan_tci. This is ensured in __netif_receive_skb_core and honored by
skb_vlan_push and skb_vlan_pop. The code dealing with such case is a dead
code.
Moreover, the likely() statement around skb_vlan_tag_present is bogus. This
code is called whenever flow key is being extracted from the packet. The
packet may be as likely vlan tagged as not.
Fixes: 018c1dda5ff1 ("openvswitch: 802.1AD Flow handling, actions, vlan parsing, netlink attributes")
Signed-off-by: Jiri Benc <redacted>
---
net/openvswitch/flow.c | 28 ++++++++--------------------
1 file changed, 8 insertions(+), 20 deletions(-)
diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index c8c82e109c68..d88c0a55b783 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c@@ -308,9 +308,7 @@ static bool icmp6hdr_ok(struct sk_buff *skb) /** * Parse vlan tag from vlan header. - * Returns ERROR on memory error. - * Returns 0 if it encounters a non-vlan or incomplete packet. - * Returns 1 after successfully parsing vlan tag. + * Returns ERROR on memory error, 0 otherwise. */ static int parse_vlan_tag(struct sk_buff *skb, struct vlan_head *key_vh) {
@@ -331,34 +329,24 @@ static int parse_vlan_tag(struct sk_buff *skb, struct vlan_head *key_vh) key_vh->tpid = vh->tpid; __skb_pull(skb, sizeof(struct vlan_head)); - return 1; + return 0; } static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key) { - int res; - key->eth.vlan.tci = 0; key->eth.vlan.tpid = 0; key->eth.cvlan.tci = 0; key->eth.cvlan.tpid = 0; - if (likely(skb_vlan_tag_present(skb))) { - key->eth.vlan.tci = htons(skb->vlan_tci); - key->eth.vlan.tpid = skb->vlan_proto; - } else { - /* Parse outer vlan tag in the non-accelerated case. */ - res = parse_vlan_tag(skb, &key->eth.vlan); - if (res <= 0) - return res; - } + if (!skb_vlan_tag_present(skb)) + return 0; - /* Parse inner vlan tag. */ - res = parse_vlan_tag(skb, &key->eth.cvlan); - if (res <= 0) - return res; + key->eth.vlan.tci = htons(skb->vlan_tci); + key->eth.vlan.tpid = skb->vlan_proto; - return 0; + /* Parse inner vlan tag. */ + return parse_vlan_tag(skb, &key->eth.cvlan); } static __be16 parse_ethertype(struct sk_buff *skb)
--
1.8.3.1