team: handle sending port list in the same way option list is sent

Essentially do the same thing with port list as with option list.
Multipart netlink message.
Side effect is that port event message can send port which is not longer
in team->port_list.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/team/team.c

@@ -1965,30 +1965,6 @@ static void team_nl_team_put(struct team *team)
 	dev_put(team->dev);
 }
 
-static int team_nl_send_generic(struct genl_info *info, struct team *team,
-				int (*fill_func)(struct sk_buff *skb,
-						 struct genl_info *info,
-						 int flags, struct team *team))
-{
-	struct sk_buff *skb;
-	int err;
-
-	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
-	if (!skb)
-		return -ENOMEM;
-
-	err = fill_func(skb, info, NLM_F_ACK, team);
-	if (err < 0)
-		goto err_fill;
-
-	err = genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
-	return err;
-
-err_fill:
-	nlmsg_free(skb);
-	return err;
-}
-
 typedef int team_nl_send_func_t(struct sk_buff *skb,
 				struct team *team, u32 portid);
 
@@ -2333,16 +2309,57 @@ static int team_nl_cmd_options_set(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
-static int team_nl_fill_port_list_get(struct sk_buff *skb,
-				      u32 portid, u32 seq, int flags,
-				      struct team *team,
-				      bool fillall)
+static int team_nl_fill_one_port_get(struct sk_buff *skb,
+				     struct team_port *port)
+{
+	struct nlattr *port_item;
+
+	port_item = nla_nest_start(skb, TEAM_ATTR_ITEM_PORT);
+	if (!port_item)
+		goto nest_cancel;
+	if (nla_put_u32(skb, TEAM_ATTR_PORT_IFINDEX, port->dev->ifindex))
+		goto nest_cancel;
+	if (port->changed) {
+		if (nla_put_flag(skb, TEAM_ATTR_PORT_CHANGED))
+			goto nest_cancel;
+		port->changed = false;
+	}
+	if ((port->removed &&
+	     nla_put_flag(skb, TEAM_ATTR_PORT_REMOVED)) ||
+	    (port->state.linkup &&
+	     nla_put_flag(skb, TEAM_ATTR_PORT_LINKUP)) ||
+	    nla_put_u32(skb, TEAM_ATTR_PORT_SPEED, port->state.speed) ||
+	    nla_put_u8(skb, TEAM_ATTR_PORT_DUPLEX, port->state.duplex))
+		goto nest_cancel;
+	nla_nest_end(skb, port_item);
+	return 0;
+
+nest_cancel:
+	nla_nest_cancel(skb, port_item);
+	return -EMSGSIZE;
+}
+
+static int team_nl_send_port_list_get(struct team *team, u32 portid, u32 seq,
+				      int flags, team_nl_send_func_t *send_func,
+				      struct team_port *one_port)
 {
 	struct nlattr *port_list;
+	struct nlmsghdr *nlh;
 	void *hdr;
 	struct team_port *port;
+	int err;
+	struct sk_buff *skb = NULL;
+	bool incomplete;
+	int i;
 
-	hdr = genlmsg_put(skb, portid, seq, &team_nl_family, flags,
+	port = list_first_entry(&team->port_list, struct team_port, list);
+
+start_again:
+	err = __send_and_alloc_skb(&skb, team, portid, send_func);
+	if (err)
+		return err;
+
+	hdr = genlmsg_put(skb, portid, seq, &team_nl_family, flags | NLM_F_MULTI,
 			  TEAM_CMD_PORT_LIST_GET);
 	if (!hdr)
 		return -EMSGSIZE;
@@ -2353,47 +2370,54 @@ static int team_nl_fill_port_list_get(struct sk_buff *skb,
 	if (!port_list)
 		goto nla_put_failure;
 
-	list_for_each_entry(port, &team->port_list, list) {
-		struct nlattr *port_item;
+	i = 0;
+	incomplete = false;
 
-		/* Include only changed ports if fill all mode is not on */
-		if (!fillall && !port->changed)
-			continue;
-		port_item = nla_nest_start(skb, TEAM_ATTR_ITEM_PORT);
-		if (!port_item)
-			goto nla_put_failure;
-		if (nla_put_u32(skb, TEAM_ATTR_PORT_IFINDEX, port->dev->ifindex))
-			goto nla_put_failure;
-		if (port->changed) {
-			if (nla_put_flag(skb, TEAM_ATTR_PORT_CHANGED))
-				goto nla_put_failure;
-			port->changed = false;
+	/* If one port is selected, called wants to send port list containing
+	 * only this port. Otherwise go through all listed ports and send all
+	 */
+	if (one_port) {
+		err = team_nl_fill_one_port_get(skb, one_port);
+		if (err)
+			goto errout;
+	} else {
+		list_for_each_entry(port, &team->port_list, list) {
+			err = team_nl_fill_one_port_get(skb, port);
+			if (err) {
+				if (err == -EMSGSIZE) {
+					if (!i)
+						goto errout;
+					incomplete = true;
+					break;
+				}
+				goto errout;
+			}
+			i++;
 		}
-		if ((port->removed &&
-		     nla_put_flag(skb, TEAM_ATTR_PORT_REMOVED)) ||
-		    (port->state.linkup &&
-		     nla_put_flag(skb, TEAM_ATTR_PORT_LINKUP)) ||
-		    nla_put_u32(skb, TEAM_ATTR_PORT_SPEED, port->state.speed) ||
-		    nla_put_u8(skb, TEAM_ATTR_PORT_DUPLEX, port->state.duplex))
-			goto nla_put_failure;
-		nla_nest_end(skb, port_item);
 	}
 
 	nla_nest_end(skb, port_list);
-	return genlmsg_end(skb, hdr);
+	genlmsg_end(skb, hdr);
+	if (incomplete)
+		goto start_again;
+
+send_done:
+	nlh = nlmsg_put(skb, portid, seq, NLMSG_DONE, 0, flags | NLM_F_MULTI);
+	if (!nlh) {
+		err = __send_and_alloc_skb(&skb, team, portid, send_func);
+		if (err)
+			goto errout;
+		goto send_done;
+	}
+
+	return send_func(skb, team, portid);
 
 nla_put_failure:
+	err = -EMSGSIZE;
+errout:
 	genlmsg_cancel(skb, hdr);
-	return -EMSGSIZE;
-}
-
-static int team_nl_fill_port_list_get_all(struct sk_buff *skb,
-					  struct genl_info *info, int flags,
-					  struct team *team)
-{
-	return team_nl_fill_port_list_get(skb, info->snd_portid,
-					  info->snd_seq, NLM_F_ACK,
-					  team, true);
+	nlmsg_free(skb);
+	return err;
 }
 
 static int team_nl_cmd_port_list_get(struct sk_buff *skb,
@@ -2406,7 +2430,8 @@ static int team_nl_cmd_port_list_get(struct sk_buff *skb,
 	if (!team)
 		return -EINVAL;
 
-	err = team_nl_send_generic(info, team, team_nl_fill_port_list_get_all);
+	err = team_nl_send_port_list_get(team, info->snd_portid, info->snd_seq,
+					 NLM_F_ACK, team_nl_send_unicast, NULL);
 
 	team_nl_team_put(team);
 
@@ -2457,27 +2482,11 @@ static int team_nl_send_event_options_get(struct team *team,
 					sel_opt_inst_list);
 }
 
-static int team_nl_send_event_port_list_get(struct team *team)
+static int team_nl_send_event_port_get(struct team *team,
+				       struct team_port *port)
 {
-	struct sk_buff *skb;
-	int err;
-	struct net *net = dev_net(team->dev);
-
-	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
-	if (!skb)
-		return -ENOMEM;
-
-	err = team_nl_fill_port_list_get(skb, 0, 0, 0, team, false);
-	if (err < 0)
-		goto err_fill;
-
-	err = genlmsg_multicast_netns(net, skb, 0, team_change_event_mcgrp.id,
-				      GFP_KERNEL);
-	return err;
-
-err_fill:
-	nlmsg_free(skb);
-	return err;
+	return team_nl_send_port_list_get(team, 0, 0, 0, team_nl_send_multicast,
+					  port);
 }
 
 static int team_nl_init(void)
@@ -2550,7 +2559,7 @@ static void __team_port_change_send(struct team_port *port, bool linkup)
 	port->state.duplex = 0;
 
 send_event:
-	err = team_nl_send_event_port_list_get(port->team);
+	err = team_nl_send_event_port_get(port->team, port);
 	if (err && err != -ESRCH)
 		netdev_warn(port->team->dev, "Failed to send port change of device %s via netlink (err %d)\n",
 			    port->dev->name, err);