openvswitch: Split ovs_flow_cmd_new_or_set().

Following patch will be easier to reason about with separate
ovs_flow_cmd_new() and ovs_flow_cmd_set() functions.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>

net/openvswitch/datapath.c

@@ -792,16 +792,16 @@ static struct sk_buff *ovs_flow_cmd_build_info(const struct sw_flow *flow,
 	return skb;
 }
 
-static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
+static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nlattr **a = info->attrs;
 	struct ovs_header *ovs_header = info->userhdr;
 	struct sw_flow_key key, masked_key;
-	struct sw_flow *flow = NULL;
+	struct sw_flow *flow;
 	struct sw_flow_mask mask;
 	struct sk_buff *reply;
 	struct datapath *dp;
-	struct sw_flow_actions *acts = NULL;
+	struct sw_flow_actions *acts;
 	struct sw_flow_match match;
 	int error;
 
@@ -817,23 +817,21 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
 		goto error;
 
 	/* Validate actions. */
-	if (a[OVS_FLOW_ATTR_ACTIONS]) {
-		acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS]));
-		error = PTR_ERR(acts);
-		if (IS_ERR(acts))
-			goto error;
+	error = -EINVAL;
+	if (!a[OVS_FLOW_ATTR_ACTIONS])
+		goto error;
 
-		ovs_flow_mask_key(&masked_key, &key, &mask);
-		error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS],
-					     &masked_key, 0, &acts);
-		if (error) {
-			OVS_NLERR("Flow actions may not be safe on all matching packets.\n");
-			goto err_kfree;
-		}
-	} else if (info->genlhdr->cmd == OVS_FLOW_CMD_NEW) {
-		/* OVS_FLOW_CMD_NEW must have actions. */
-		error = -EINVAL;
+	acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS]));
+	error = PTR_ERR(acts);
+	if (IS_ERR(acts))
 		goto error;
+
+	ovs_flow_mask_key(&masked_key, &key, &mask);
+	error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS],
+				     &masked_key, 0, &acts);
+	if (error) {
+		OVS_NLERR("Flow actions may not be safe on all matching packets.\n");
+		goto err_kfree;
 	}
 
 	ovs_lock();
@@ -845,11 +843,6 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
 	/* Check if this is a duplicate flow */
 	flow = ovs_flow_tbl_lookup(&dp->table, &key);
 	if (!flow) {
-		/* Bail out if we're not allowed to create a new flow. */
-		error = -ENOENT;
-		if (info->genlhdr->cmd == OVS_FLOW_CMD_SET)
-			goto err_unlock_ovs;
-
 		/* Allocate flow. */
 		flow = ovs_flow_alloc();
 		if (IS_ERR(flow)) {
@@ -867,11 +860,9 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
 			acts = NULL;
 			goto err_flow_free;
 		}
-
-		reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex,
-						info, OVS_FLOW_CMD_NEW, false);
 	} else {
-		/* We found a matching flow. */
+		struct sw_flow_actions *old_acts;
+
 		/* Bail out if we're not allowed to modify an existing flow.
 		 * We accept NLM_F_CREATE in place of the intended NLM_F_EXCL
 		 * because Generic Netlink treats the latter as a dump
@@ -879,30 +870,113 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
 		 * gets fixed.
 		 */
 		error = -EEXIST;
-		if (info->genlhdr->cmd == OVS_FLOW_CMD_NEW &&
-		    info->nlhdr->nlmsg_flags & (NLM_F_CREATE | NLM_F_EXCL))
+		if (info->nlhdr->nlmsg_flags & (NLM_F_CREATE | NLM_F_EXCL))
 			goto err_unlock_ovs;
 
 		/* The unmasked key has to be the same for flow updates. */
 		if (!ovs_flow_cmp_unmasked_key(flow, &match))
 			goto err_unlock_ovs;
 
-		/* Update actions, if present. */
-		if (acts) {
-			struct sw_flow_actions *old_acts;
+		/* Update actions. */
+		old_acts = ovsl_dereference(flow->sf_acts);
+		rcu_assign_pointer(flow->sf_acts, acts);
+		ovs_nla_free_flow_actions(old_acts);
+	}
+
+	reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex,
+					info, OVS_FLOW_CMD_NEW, false);
+	ovs_unlock();
+
+	if (reply) {
+		if (!IS_ERR(reply))
+			ovs_notify(&dp_flow_genl_family, reply, info);
+		else
+			netlink_set_err(sock_net(skb->sk)->genl_sock, 0, 0,
+					PTR_ERR(reply));
+	}
+	return 0;
+
+err_flow_free:
+	ovs_flow_free(flow, false);
+err_unlock_ovs:
+	ovs_unlock();
+err_kfree:
+	kfree(acts);
+error:
+	return error;
+}
 
-			old_acts = ovsl_dereference(flow->sf_acts);
-			rcu_assign_pointer(flow->sf_acts, acts);
-			ovs_nla_free_flow_actions(old_acts);
+static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr **a = info->attrs;
+	struct ovs_header *ovs_header = info->userhdr;
+	struct sw_flow_key key, masked_key;
+	struct sw_flow *flow;
+	struct sw_flow_mask mask;
+	struct sk_buff *reply = NULL;
+	struct datapath *dp;
+	struct sw_flow_actions *acts = NULL;
+	struct sw_flow_match match;
+	int error;
+
+	/* Extract key. */
+	error = -EINVAL;
+	if (!a[OVS_FLOW_ATTR_KEY])
+		goto error;
+
+	ovs_match_init(&match, &key, &mask);
+	error = ovs_nla_get_match(&match,
+				  a[OVS_FLOW_ATTR_KEY], a[OVS_FLOW_ATTR_MASK]);
+	if (error)
+		goto error;
+
+	/* Validate actions. */
+	if (a[OVS_FLOW_ATTR_ACTIONS]) {
+		acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS]));
+		error = PTR_ERR(acts);
+		if (IS_ERR(acts))
+			goto error;
+
+		ovs_flow_mask_key(&masked_key, &key, &mask);
+		error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS],
+					     &masked_key, 0, &acts);
+		if (error) {
+			OVS_NLERR("Flow actions may not be safe on all matching packets.\n");
+			goto err_kfree;
 		}
+	}
 
-		reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex,
-						info, OVS_FLOW_CMD_NEW, false);
+	ovs_lock();
+	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
+	error = -ENODEV;
+	if (!dp)
+		goto err_unlock_ovs;
+
+	/* Check that the flow exists. */
+	flow = ovs_flow_tbl_lookup(&dp->table, &key);
+	error = -ENOENT;
+	if (!flow)
+		goto err_unlock_ovs;
+
+	/* The unmasked key has to be the same for flow updates. */
+	error = -EEXIST;
+	if (!ovs_flow_cmp_unmasked_key(flow, &match))
+		goto err_unlock_ovs;
 
-		/* Clear stats. */
-		if (a[OVS_FLOW_ATTR_CLEAR])
-			ovs_flow_stats_clear(flow);
+	/* Update actions, if present. */
+	if (acts) {
+		struct sw_flow_actions *old_acts;
+
+		old_acts = ovsl_dereference(flow->sf_acts);
+		rcu_assign_pointer(flow->sf_acts, acts);
+		ovs_nla_free_flow_actions(old_acts);
 	}
+
+	reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex,
+					info, OVS_FLOW_CMD_NEW, false);
+	/* Clear stats. */
+	if (a[OVS_FLOW_ATTR_CLEAR])
+		ovs_flow_stats_clear(flow);
 	ovs_unlock();
 
 	if (reply) {
@@ -915,8 +989,6 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
 
 	return 0;
 
-err_flow_free:
-	ovs_flow_free(flow, false);
 err_unlock_ovs:
 	ovs_unlock();
 err_kfree:
@@ -1078,7 +1150,7 @@ static const struct genl_ops dp_flow_genl_ops[] = {
 	{ .cmd = OVS_FLOW_CMD_NEW,
 	  .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
 	  .policy = flow_policy,
-	  .doit = ovs_flow_cmd_new_or_set
+	  .doit = ovs_flow_cmd_new
 	},
 	{ .cmd = OVS_FLOW_CMD_DEL,
 	  .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
@@ -1094,7 +1166,7 @@ static const struct genl_ops dp_flow_genl_ops[] = {
 	{ .cmd = OVS_FLOW_CMD_SET,
 	  .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
 	  .policy = flow_policy,
-	  .doit = ovs_flow_cmd_new_or_set,
+	  .doit = ovs_flow_cmd_set,
 	},
 };