openvswitch: Pad OVS_PACKET_ATTR_PACKET if linear copy was performed
authorThomas Graf <tgraf@suug.ch>
Tue, 14 Jan 2014 16:27:49 +0000 (16:27 +0000)
committerJesse Gross <jesse@nicira.com>
Wed, 5 Feb 2014 06:21:11 +0000 (22:21 -0800)
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>
net/openvswitch/datapath.c

index df4692826ead9ef8b5761f58ef7218bf4b3f5119..d1a73a6102f8767048a6643d5a4bac75335a40e7 100644 (file)
@@ -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);