From: Jesse Gross Date: Thu, 8 Sep 2011 22:32:24 +0000 (-0700) Subject: datapath: Calculate flow hash after extracting metadata. X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0fe255dfbf37fa7ddc23c2593c512c092b0f61d7;p=openvswitch datapath: Calculate flow hash after extracting metadata. When we execute a packet from userspace we first extract the header fields from the packet and then add supplied metadata. However, we compute the hash of the packet in between these two steps despite the fact that the metadata can affect the hash. This can lead to two separate hashes for packets of the same flow. Found by code inspection, not an actual real-world problem. Signed-off-by: Jesse Gross Acked-by: Ben Pfaff --- diff --git a/datapath/datapath.c b/datapath/datapath.c index 74990818..b92c198d 100644 --- a/datapath/datapath.c +++ b/datapath/datapath.c @@ -686,7 +686,6 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info) err = flow_extract(packet, -1, &flow->key, &key_len, &is_frag); if (err) goto err_flow_put; - flow->tbl_node.hash = flow_hash(&flow->key, key_len); err = flow_metadata_from_nlattrs(&flow->key.eth.in_port, &flow->key.eth.tun_id, @@ -694,6 +693,8 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info) if (err) goto err_flow_put; + flow->tbl_node.hash = flow_hash(&flow->key, key_len); + acts = flow_actions_alloc(a[OVS_PACKET_ATTR_ACTIONS]); err = PTR_ERR(acts); if (IS_ERR(acts))