Use netlink_has_listeners() and NLM_F_ECHO flag to determine if a
reply is needed or not for OVS_FLOW_CMD_NEW, OVS_FLOW_CMD_SET, or
OVS_FLOW_CMD_DEL. Currently, OVS userspace does not request a reply
for OVS_FLOW_CMD_NEW, but usually does for OVS_FLOW_CMD_DEL, as stats
may have changed.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
int ovs_net_id __read_mostly;
int ovs_net_id __read_mostly;
+/* Check if need to build a reply message.
+ * OVS userspace sets the NLM_F_ECHO flag if it needs the reply. */
+static bool ovs_must_notify(struct genl_info *info,
+ const struct genl_multicast_group *grp)
+{
+ return info->nlhdr->nlmsg_flags & NLM_F_ECHO ||
+ netlink_has_listeners(genl_info_net(info)->genl_sock, grp->id);
+}
+
static void ovs_notify(struct sk_buff *skb, struct genl_info *info,
struct genl_multicast_group *grp)
{
static void ovs_notify(struct sk_buff *skb, struct genl_info *info,
struct genl_multicast_group *grp)
{
/* Must be called with ovs_mutex. */
static struct sk_buff *ovs_flow_cmd_alloc_info(struct sw_flow *flow,
/* Must be called with ovs_mutex. */
static struct sk_buff *ovs_flow_cmd_alloc_info(struct sw_flow *flow,
- struct genl_info *info)
+ struct genl_info *info,
+ bool always)
+ if (!always && !ovs_must_notify(info, &ovs_dp_flow_multicast_group))
+ return NULL;
+
len = ovs_flow_cmd_msg_size(ovsl_dereference(flow->sf_acts));
len = ovs_flow_cmd_msg_size(ovsl_dereference(flow->sf_acts));
- return genlmsg_new_unicast(len, info, GFP_KERNEL);
+ skb = genlmsg_new_unicast(len, info, GFP_KERNEL);
+
+ if (!skb)
+ return ERR_PTR(-ENOMEM);
+
+ return skb;
}
/* Must be called with ovs_mutex. */
static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
struct datapath *dp,
struct genl_info *info,
}
/* Must be called with ovs_mutex. */
static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
struct datapath *dp,
struct genl_info *info,
{
struct sk_buff *skb;
int retval;
{
struct sk_buff *skb;
int retval;
- skb = ovs_flow_cmd_alloc_info(flow, info);
- if (!skb)
- return ERR_PTR(-ENOMEM);
+ skb = ovs_flow_cmd_alloc_info(flow, info, always);
+ if (!skb || IS_ERR(skb))
+ return skb;
retval = ovs_flow_cmd_fill_info(flow, dp, skb, info->snd_portid,
info->snd_seq, 0, cmd);
retval = ovs_flow_cmd_fill_info(flow, dp, skb, info->snd_portid,
info->snd_seq, 0, cmd);
- reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
+ reply = ovs_flow_cmd_build_info(flow, dp, info,
+ OVS_FLOW_CMD_NEW, false);
} else {
/* We found a matching flow. */
/* Bail out if we're not allowed to modify an existing flow.
} else {
/* We found a matching flow. */
/* Bail out if we're not allowed to modify an existing flow.
rcu_assign_pointer(flow->sf_acts, acts);
ovs_nla_free_flow_actions(old_acts);
}
rcu_assign_pointer(flow->sf_acts, acts);
ovs_nla_free_flow_actions(old_acts);
}
- reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
+ reply = ovs_flow_cmd_build_info(flow, dp, info,
+ OVS_FLOW_CMD_NEW, false);
/* Clear stats. */
if (a[OVS_FLOW_ATTR_CLEAR])
/* Clear stats. */
if (a[OVS_FLOW_ATTR_CLEAR])
- if (!IS_ERR(reply))
- ovs_notify(reply, info, &ovs_dp_flow_multicast_group);
- else
- netlink_set_err(sock_net(skb->sk)->genl_sock, 0,
- ovs_dp_flow_multicast_group.id, PTR_ERR(reply));
+ if (reply) {
+ if (!IS_ERR(reply))
+ ovs_notify(reply, info, &ovs_dp_flow_multicast_group);
+ else
+ netlink_set_err(sock_net(skb->sk)->genl_sock, 0,
+ ovs_dp_flow_multicast_group.id,
+ PTR_ERR(reply));
+ }
- reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
+ reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW, true);
if (IS_ERR(reply)) {
err = PTR_ERR(reply);
goto unlock;
if (IS_ERR(reply)) {
err = PTR_ERR(reply);
goto unlock;
- reply = ovs_flow_cmd_alloc_info(flow, info);
- if (!reply) {
- err = -ENOMEM;
+ reply = ovs_flow_cmd_alloc_info(flow, info, false);
+ if (IS_ERR(reply)) {
+ err = PTR_ERR(reply);
goto unlock;
}
ovs_flow_tbl_remove(&dp->table, flow);
goto unlock;
}
ovs_flow_tbl_remove(&dp->table, flow);
- err = ovs_flow_cmd_fill_info(flow, dp, reply, info->snd_portid,
- info->snd_seq, 0, OVS_FLOW_CMD_DEL);
- BUG_ON(err < 0);
+ if (reply) {
+ err = ovs_flow_cmd_fill_info(flow, dp, reply, info->snd_portid,
+ info->snd_seq, 0,
+ OVS_FLOW_CMD_DEL);
+ BUG_ON(err < 0);
+ }
ovs_flow_free(flow, true);
ovs_unlock();
ovs_flow_free(flow, true);
ovs_unlock();
- ovs_notify(reply, info, &ovs_dp_flow_multicast_group);
+ if (reply)
+ ovs_notify(reply, info, &ovs_dp_flow_multicast_group);
return 0;
unlock:
ovs_unlock();
return 0;
unlock:
ovs_unlock();