openvswitch: Add packet truncation support.
The patch adds a new OVS action, OVS_ACTION_ATTR_TRUNC, in order to
truncate packets. A 'max_len' is added for setting up the maximum
packet size, and a 'cutlen' field is to record the number of bytes
to trim the packet when the packet is outputting to a port, or when
the packet is sent to userspace.
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>
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 856bd8d..6739342 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -137,10 +137,12 @@
static struct vport *new_vport(const struct vport_parms *);
static int queue_gso_packets(struct datapath *dp, struct sk_buff *,
const struct sw_flow_key *,
- const struct dp_upcall_info *);
+ const struct dp_upcall_info *,
+ uint32_t cutlen);
static int queue_userspace_packet(struct datapath *dp, struct sk_buff *,
const struct sw_flow_key *,
- const struct dp_upcall_info *);
+ const struct dp_upcall_info *,
+ uint32_t cutlen);
/* Must be called with rcu_read_lock. */
static struct datapath *get_dp_rcu(struct net *net, int dp_ifindex)
@@ -275,7 +277,7 @@
upcall.cmd = OVS_PACKET_CMD_MISS;
upcall.portid = ovs_vport_find_upcall_portid(p, skb);
upcall.mru = OVS_CB(skb)->mru;
- error = ovs_dp_upcall(dp, skb, key, &upcall);
+ error = ovs_dp_upcall(dp, skb, key, &upcall, 0);
if (unlikely(error))
kfree_skb(skb);
else
@@ -300,7 +302,8 @@
int ovs_dp_upcall(struct datapath *dp, struct sk_buff *skb,
const struct sw_flow_key *key,
- const struct dp_upcall_info *upcall_info)
+ const struct dp_upcall_info *upcall_info,
+ uint32_t cutlen)
{
struct dp_stats_percpu *stats;
int err;
@@ -311,9 +314,9 @@
}
if (!skb_is_gso(skb))
- err = queue_userspace_packet(dp, skb, key, upcall_info);
+ err = queue_userspace_packet(dp, skb, key, upcall_info, cutlen);
else
- err = queue_gso_packets(dp, skb, key, upcall_info);
+ err = queue_gso_packets(dp, skb, key, upcall_info, cutlen);
if (err)
goto err;
@@ -331,7 +334,8 @@
static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb,
const struct sw_flow_key *key,
- const struct dp_upcall_info *upcall_info)
+ const struct dp_upcall_info *upcall_info,
+ uint32_t cutlen)
{
unsigned short gso_type = skb_shinfo(skb)->gso_type;
struct sw_flow_key later_key;
@@ -360,7 +364,7 @@
if (gso_type & SKB_GSO_UDP && skb != segs)
key = &later_key;
- err = queue_userspace_packet(dp, skb, key, upcall_info);
+ err = queue_userspace_packet(dp, skb, key, upcall_info, cutlen);
if (err)
break;
@@ -416,7 +420,8 @@
static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
const struct sw_flow_key *key,
- const struct dp_upcall_info *upcall_info)
+ const struct dp_upcall_info *upcall_info,
+ uint32_t cutlen)
{
struct ovs_header *upcall;
struct sk_buff *nskb = NULL;
@@ -461,7 +466,7 @@
else
hlen = skb->len;
- len = upcall_msg_size(upcall_info, hlen);
+ len = upcall_msg_size(upcall_info, hlen - cutlen);
user_skb = genlmsg_new(len, GFP_ATOMIC);
if (!user_skb) {
err = -ENOMEM;
@@ -515,9 +520,9 @@
err = -ENOBUFS;
goto out;
}
- nla->nla_len = nla_attr_size(skb->len);
+ nla->nla_len = nla_attr_size(skb->len - cutlen);
- err = skb_zerocopy(user_skb, skb, skb->len, hlen);
+ err = skb_zerocopy(user_skb, skb, skb->len - cutlen, hlen);
if (err)
goto out;