Commit fb5d1e9e authored by Jarno Rajahalme's avatar Jarno Rajahalme Committed by Pravin B Shelar
Browse files

openvswitch: Build flow cmd netlink reply only if needed. 



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: default avatarJarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: default avatarPravin B Shelar <pshelar@nicira.com>
parent bb6f9a70

net/openvswitch/datapath.c

+48 −22
Original line number Diff line number Diff line
@@ -62,6 +62,15 @@ 


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, 0);

}



static void ovs_notify(struct genl_family *family,

		       struct sk_buff *skb, struct genl_info *info)

{
@@ -746,27 +755,36 @@ error: 


/* 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)

{

	struct sk_buff *skb;

	size_t len;



	if (!always && !ovs_must_notify(info, &ovs_dp_flow_multicast_group))

		return NULL;



	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,

					       u8 cmd)

					       u8 cmd, bool always)

{

	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);
@@ -850,7 +868,8 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info) 
			goto err_flow_free;

		}



		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.
@@ -876,7 +895,8 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info) 
			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])
@@ -884,11 +904,14 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info) 
	}

	ovs_unlock();



	if (reply) {

		if (!IS_ERR(reply))

			ovs_notify(&dp_flow_genl_family, reply, info);

		else

			genl_set_err(&dp_flow_genl_family, sock_net(skb->sk), 0,

				     0, PTR_ERR(reply));

	}



	return 0;



err_flow_free:
@@ -935,7 +958,7 @@ static int ovs_flow_cmd_get(struct sk_buff *skb, struct genl_info *info) 
		goto unlock;

	}



	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;
@@ -982,21 +1005,24 @@ static int ovs_flow_cmd_del(struct sk_buff *skb, struct genl_info *info) 
		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);



	if (reply) {

		err = ovs_flow_cmd_fill_info(flow, dp, reply, info->snd_portid,

				     info->snd_seq, 0, OVS_FLOW_CMD_DEL);

					     info->snd_seq, 0,

					     OVS_FLOW_CMD_DEL);

		BUG_ON(err < 0);



	}

	ovs_flow_free(flow, true);

	ovs_unlock();



	if (reply)

		ovs_notify(&dp_flow_genl_family, reply, info);

	return 0;

unlock:

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