openvswitch: Pad OVS_PACKET_ATTR_PACKET if linear copy was performed

While the zerocopy method is correctly omitted if user space
does not support unaligned Netlink messages. The attribute is
still not padded correctly as skb_zerocopy() will not ensure
padding and the attribute size is no longer pre calculated
though nla_reserve() which ensured padding previously.

This patch applies appropriate padding if a linear data copy
was performed in skb_zerocopy().

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index df4692826ead9ef8b5761f58ef7218bf4b3f5119..d1a73a6102f8767048a6643d5a4bac75335a40e7 100644 (file)
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -466,6 +466,14 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
 
        skb_zerocopy(user_skb, skb, skb->len, hlen);
 
+       /* Pad OVS_PACKET_ATTR_PACKET if linear copy was performed */
+       if (!(dp->user_features & OVS_DP_F_UNALIGNED)) {
+               size_t plen = NLA_ALIGN(user_skb->len) - user_skb->len;
+
+               if (plen > 0)
+                       memset(skb_put(user_skb, plen), 0, plen);
+       }
+
        ((struct nlmsghdr *) user_skb->data)->nlmsg_len = user_skb->len;
 
        err = genlmsg_unicast(ovs_dp_get_net(dp), user_skb, upcall_info->portid);