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authorWilliam Tu <u9012063@gmail.com>2016-06-20 07:26:17 -0700
committerDavid S. Miller <davem@davemloft.net>2016-06-22 16:34:39 -0400
commitb95e5928fcc76d156352570858abdea7b2628efd (patch)
treea1957ca55d8e3a9d49af276d1b347340de0256c7 /net/openvswitch
parent904632a224b2ea39920e526cdc93565aaf1fb43e (diff)
openvswitch: Add packet len info to upcall.
The commit f2a4d086ed4c ("openvswitch: Add packet truncation support.") introduces packet truncation before sending to userspace upcall receiver. This patch passes up the skb->len before truncation so that the upcall receiver knows the original packet size. Potentially this will be used by sFlow, where OVS translates sFlow config header=N to a sample action, truncating packet to N byte in kernel datapath. Thus, only N bytes instead of full-packet size is copied from kernel to userspace, saving the kernel-to-userspace bandwidth. Signed-off-by: William Tu <u9012063@gmail.com> Cc: Pravin Shelar <pshelar@nicira.com> Acked-by: Pravin B Shelar <pshelar@ovn.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/openvswitch')
-rw-r--r--net/openvswitch/datapath.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 673934295333..524c0fd3078e 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -387,7 +387,8 @@ static size_t upcall_msg_size(const struct dp_upcall_info *upcall_info,
{
size_t size = NLMSG_ALIGN(sizeof(struct ovs_header))
+ nla_total_size(hdrlen) /* OVS_PACKET_ATTR_PACKET */
- + nla_total_size(ovs_key_attr_size()); /* OVS_PACKET_ATTR_KEY */
+ + nla_total_size(ovs_key_attr_size()) /* OVS_PACKET_ATTR_KEY */
+ + nla_total_size(sizeof(unsigned int)); /* OVS_PACKET_ATTR_LEN */
/* OVS_PACKET_ATTR_USERDATA */
if (upcall_info->userdata)
@@ -514,6 +515,16 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
pad_packet(dp, user_skb);
}
+ /* Add OVS_PACKET_ATTR_LEN when packet is truncated */
+ if (cutlen > 0) {
+ if (nla_put_u32(user_skb, OVS_PACKET_ATTR_LEN,
+ skb->len)) {
+ err = -ENOBUFS;
+ goto out;
+ }
+ pad_packet(dp, user_skb);
+ }
+
/* Only reserve room for attribute header, packet data is added
* in skb_zerocopy() */
if (!(nla = nla_reserve(user_skb, OVS_PACKET_ATTR_PACKET, 0))) {