rtnetlink: pass netlink message header and portid to rtnl_configure_link()

This patch pass netlink message header and portid to rtnl_configure_link()
All the functions in this call chain need to add the parameters so we can
use them in the last call rtnl_notify(), and notify the userspace about
the new link info if NLM_F_ECHO flag is set.

- rtnl_configure_link()
  - __dev_notify_flags()
    - rtmsg_ifinfo()
      - rtmsg_ifinfo_event()
        - rtmsg_ifinfo_build_skb()
        - rtmsg_ifinfo_send()
	  - rtnl_notify()

Also move __dev_notify_flags() declaration to net/core/dev.h, as Jakub
suggested.
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/can/vxcan.c

@@ -236,7 +236,7 @@ static int vxcan_newlink(struct net *net, struct net_device *dev,
 
 	netif_carrier_off(peer);
 
-	err = rtnl_configure_link(peer, ifmp);
+	err = rtnl_configure_link(peer, ifmp, 0, NULL);
 	if (err < 0)
 		goto unregister_network_device;
 

drivers/net/geneve.c

@@ -1907,7 +1907,7 @@ struct net_device *geneve_dev_create_fb(struct net *net, const char *name,
 	if (err)
 		goto err;
 
-	err = rtnl_configure_link(dev, NULL);
+	err = rtnl_configure_link(dev, NULL, 0, NULL);
 	if (err < 0)
 		goto err;
 

drivers/net/veth.c

@@ -1773,7 +1773,7 @@ static int veth_newlink(struct net *src_net, struct net_device *dev,
 	veth_disable_gro(peer);
 	netif_carrier_off(peer);
 
-	err = rtnl_configure_link(peer, ifmp);
+	err = rtnl_configure_link(peer, ifmp, 0, NULL);
 	if (err < 0)
 		goto err_configure_peer;
 

drivers/net/vxlan/vxlan_core.c

@@ -3794,7 +3794,7 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev,
 			goto errout;
 	}
 
-	err = rtnl_configure_link(dev, NULL);
+	err = rtnl_configure_link(dev, NULL, 0, NULL);
 	if (err < 0)
 		goto unlink;
 
@@ -4416,7 +4416,7 @@ struct net_device *vxlan_dev_create(struct net *net, const char *name,
 		return ERR_PTR(err);
 	}
 
-	err = rtnl_configure_link(dev, NULL);
+	err = rtnl_configure_link(dev, NULL, 0, NULL);
 	if (err < 0) {
 		LIST_HEAD(list_kill);
 

drivers/net/wwan/wwan_core.c

@@ -1058,7 +1058,7 @@ static void wwan_create_default_link(struct wwan_device *wwandev,
 		goto unlock;
 	}
 
-	rtnl_configure_link(dev, NULL); /* Link initialized, notify new link */
+	rtnl_configure_link(dev, NULL, 0, NULL); /* Link initialized, notify new link */
 
 unlock:
 	rtnl_unlock();

include/linux/netdevice.h

@@ -3855,8 +3855,6 @@ int __dev_change_flags(struct net_device *dev, unsigned int flags,
 		       struct netlink_ext_ack *extack);
 int dev_change_flags(struct net_device *dev, unsigned int flags,
 		     struct netlink_ext_ack *extack);
-void __dev_notify_flags(struct net_device *, unsigned int old_flags,
-			unsigned int gchanges);
 int dev_set_alias(struct net_device *, const char *, size_t);
 int dev_get_alias(const struct net_device *, char *, size_t);
 int __dev_change_net_namespace(struct net_device *dev, struct net *net,

include/linux/rtnetlink.h

@@ -12,21 +12,22 @@
 extern int rtnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, u32 group, int echo);
 extern int rtnl_unicast(struct sk_buff *skb, struct net *net, u32 pid);
 extern void rtnl_notify(struct sk_buff *skb, struct net *net, u32 pid,
-			u32 group, struct nlmsghdr *nlh, gfp_t flags);
+			u32 group, const struct nlmsghdr *nlh, gfp_t flags);
 extern void rtnl_set_sk_err(struct net *net, u32 group, int error);
 extern int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics);
 extern int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst,
 			      u32 id, long expires, u32 error);
 
-void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change, gfp_t flags);
+void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change, gfp_t flags,
+		  u32 portid, const struct nlmsghdr *nlh);
 void rtmsg_ifinfo_newnet(int type, struct net_device *dev, unsigned int change,
 			 gfp_t flags, int *new_nsid, int new_ifindex);
 struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
 				       unsigned change, u32 event,
 				       gfp_t flags, int *new_nsid,
-				       int new_ifindex);
+				       int new_ifindex, u32 portid, u32 seq);
 void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev,
-		       gfp_t flags);
+		       gfp_t flags, u32 portid, const struct nlmsghdr *nlh);
 
 
 /* RTNL is used as a global lock for all changes to network configuration  */

include/net/netlink.h

@@ -899,6 +899,17 @@ static inline int nlmsg_report(const struct nlmsghdr *nlh)
 	return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0;
 }
 
+/**
+ * nlmsg_seq - return the seq number of netlink message
+ * @nlh: netlink message header
+ *
+ * Returns 0 if netlink message is NULL
+ */
+static inline u32 nlmsg_seq(const struct nlmsghdr *nlh)
+{
+	return nlh ? nlh->nlmsg_seq : 0;
+}
+
 /**
  * nlmsg_for_each_attr - iterate over a stream of attributes
  * @pos: loop counter, set to current attribute

include/net/rtnetlink.h

@@ -187,7 +187,8 @@ struct net_device *rtnl_create_link(struct net *net, const char *ifname,
 				    struct nlattr *tb[],
 				    struct netlink_ext_ack *extack);
 int rtnl_delete_link(struct net_device *dev);
-int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm);
+int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm,
+			u32 portid, const struct nlmsghdr *nlh);
 
 int rtnl_nla_parse_ifla(struct nlattr **tb, const struct nlattr *head, int len,
 			struct netlink_ext_ack *exterr);

net/core/dev.c

@@ -1333,7 +1333,7 @@ void netdev_state_change(struct net_device *dev)
 
 		call_netdevice_notifiers_info(NETDEV_CHANGE,
 					      &change_info.info);
-		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
+		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL, 0, NULL);
 	}
 }
 EXPORT_SYMBOL(netdev_state_change);
@@ -1469,7 +1469,7 @@ int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
 	if (ret < 0)
 		return ret;
 
-	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
+	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
 	call_netdevice_notifiers(NETDEV_UP, dev);
 
 	return ret;
@@ -1541,7 +1541,7 @@ void dev_close_many(struct list_head *head, bool unlink)
 	__dev_close_many(head);
 
 	list_for_each_entry_safe(dev, tmp, head, close_list) {
-		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
+		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
 		call_netdevice_notifiers(NETDEV_DOWN, dev);
 		if (unlink)
 			list_del_init(&dev->close_list);
@@ -8351,7 +8351,7 @@ static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
 		dev_change_rx_flags(dev, IFF_PROMISC);
 	}
 	if (notify)
-		__dev_notify_flags(dev, old_flags, IFF_PROMISC);
+		__dev_notify_flags(dev, old_flags, IFF_PROMISC, 0, NULL);
 	return 0;
 }
 
@@ -8406,7 +8406,7 @@ static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
 		dev_set_rx_mode(dev);
 		if (notify)
 			__dev_notify_flags(dev, old_flags,
-					   dev->gflags ^ old_gflags);
+					   dev->gflags ^ old_gflags, 0, NULL);
 	}
 	return 0;
 }
@@ -8569,12 +8569,13 @@ int __dev_change_flags(struct net_device *dev, unsigned int flags,
 }
 
 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
-			unsigned int gchanges)
+			unsigned int gchanges, u32 portid,
+			const struct nlmsghdr *nlh)
 {
 	unsigned int changes = dev->flags ^ old_flags;
 
 	if (gchanges)
-		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC);
+		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC, portid, nlh);
 
 	if (changes & IFF_UP) {
 		if (dev->flags & IFF_UP)
@@ -8616,7 +8617,7 @@ int dev_change_flags(struct net_device *dev, unsigned int flags,
 		return ret;
 
 	changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
-	__dev_notify_flags(dev, old_flags, changes);
+	__dev_notify_flags(dev, old_flags, changes, 0, NULL);
 	return ret;
 }
 EXPORT_SYMBOL(dev_change_flags);
@@ -10101,7 +10102,7 @@ int register_netdevice(struct net_device *dev)
 	 */
 	if (!dev->rtnl_link_ops ||
 	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
-		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
+		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
 
 out:
 	return ret;
@@ -10849,7 +10850,7 @@ void unregister_netdevice_many(struct list_head *head)
 		if (!dev->rtnl_link_ops ||
 		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
 			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
-						     GFP_KERNEL, NULL, 0);
+						     GFP_KERNEL, NULL, 0, 0, 0);
 
 		/*
 		 *	Flush the unicast and multicast chains
@@ -10864,7 +10865,7 @@ void unregister_netdevice_many(struct list_head *head)
 			dev->netdev_ops->ndo_uninit(dev);
 
 		if (skb)
-			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL);
+			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL, 0, NULL);
 
 		/* Notifier chain MUST detach us all upper devices. */
 		WARN_ON(netdev_has_any_upper_dev(dev));
@@ -11042,7 +11043,7 @@ int __dev_change_net_namespace(struct net_device *dev, struct net *net,
 	 *	Prevent userspace races by waiting until the network
 	 *	device is fully setup before sending notifications.
 	 */
-	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
+	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
 
 	synchronize_net();
 	err = 0;

net/core/dev.h

@@ -88,6 +88,10 @@ int dev_change_carrier(struct net_device *dev, bool new_carrier);
 
 void __dev_set_rx_mode(struct net_device *dev);
 
+void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
+			unsigned int gchanges, u32 portid,
+			const struct nlmsghdr *nlh);
+
 static inline void netif_set_gso_max_size(struct net_device *dev,
 					  unsigned int size)
 {

net/core/rtnetlink.c

@@ -760,7 +760,7 @@ int rtnl_unicast(struct sk_buff *skb, struct net *net, u32 pid)
 EXPORT_SYMBOL(rtnl_unicast);
 
 void rtnl_notify(struct sk_buff *skb, struct net *net, u32 pid, u32 group,
-		 struct nlmsghdr *nlh, gfp_t flags)
+		 const struct nlmsghdr *nlh, gfp_t flags)
 {
 	struct sock *rtnl = net->rtnl;
 
@@ -3180,7 +3180,8 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
 	return err;
 }
 
-int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm)
+int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm,
+			u32 portid, const struct nlmsghdr *nlh)
 {
 	unsigned int old_flags;
 	int err;
@@ -3194,10 +3195,10 @@ int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm)
 	}
 
 	if (dev->rtnl_link_state == RTNL_LINK_INITIALIZED) {
-		__dev_notify_flags(dev, old_flags, (old_flags ^ dev->flags));
+		__dev_notify_flags(dev, old_flags, (old_flags ^ dev->flags), portid, nlh);
 	} else {
 		dev->rtnl_link_state = RTNL_LINK_INITIALIZED;
-		__dev_notify_flags(dev, old_flags, ~0U);
+		__dev_notify_flags(dev, old_flags, ~0U, portid, nlh);
 	}
 	return 0;
 }
@@ -3369,7 +3370,7 @@ static int rtnl_newlink_create(struct sk_buff *skb, struct ifinfomsg *ifm,
 		goto out;
 	}
 
-	err = rtnl_configure_link(dev, ifm);
+	err = rtnl_configure_link(dev, ifm, 0, NULL);
 	if (err < 0)
 		goto out_unregister;
 	if (link_net) {
@@ -3896,7 +3897,7 @@ static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
 struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
 				       unsigned int change,
 				       u32 event, gfp_t flags, int *new_nsid,
-				       int new_ifindex)
+				       int new_ifindex, u32 portid, u32 seq)
 {
 	struct net *net = dev_net(dev);
 	struct sk_buff *skb;
@@ -3907,7 +3908,7 @@ struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
 		goto errout;
 
 	err = rtnl_fill_ifinfo(skb, dev, dev_net(dev),
-			       type, 0, 0, change, 0, 0, event,
+			       type, portid, seq, change, 0, 0, event,
 			       new_nsid, new_ifindex, -1, flags);
 	if (err < 0) {
 		/* -EMSGSIZE implies BUG in if_nlmsg_size() */
@@ -3922,16 +3923,18 @@ struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
 	return NULL;
 }
 
-void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev, gfp_t flags)
+void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev, gfp_t flags,
+		       u32 portid, const struct nlmsghdr *nlh)
 {
 	struct net *net = dev_net(dev);
 
-	rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, flags);
+	rtnl_notify(skb, net, portid, RTNLGRP_LINK, nlh, flags);
 }
 
 static void rtmsg_ifinfo_event(int type, struct net_device *dev,
 			       unsigned int change, u32 event,
-			       gfp_t flags, int *new_nsid, int new_ifindex)
+			       gfp_t flags, int *new_nsid, int new_ifindex,
+			       u32 portid, const struct nlmsghdr *nlh)
 {
 	struct sk_buff *skb;
 
@@ -3939,23 +3942,23 @@ static void rtmsg_ifinfo_event(int type, struct net_device *dev,
 		return;
 
 	skb = rtmsg_ifinfo_build_skb(type, dev, change, event, flags, new_nsid,
-				     new_ifindex);
+				     new_ifindex, portid, nlmsg_seq(nlh));
 	if (skb)
-		rtmsg_ifinfo_send(skb, dev, flags);
+		rtmsg_ifinfo_send(skb, dev, flags, portid, nlh);
 }
 
 void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change,
-		  gfp_t flags)
+		  gfp_t flags, u32 portid, const struct nlmsghdr *nlh)
 {
 	rtmsg_ifinfo_event(type, dev, change, rtnl_get_event(0), flags,
-			   NULL, 0);
+			   NULL, 0, portid, nlh);
 }
 
 void rtmsg_ifinfo_newnet(int type, struct net_device *dev, unsigned int change,
 			 gfp_t flags, int *new_nsid, int new_ifindex)
 {
 	rtmsg_ifinfo_event(type, dev, change, rtnl_get_event(0), flags,
-			   new_nsid, new_ifindex);
+			   new_nsid, new_ifindex, 0, NULL);
 }
 
 static int nlmsg_populate_fdb_fill(struct sk_buff *skb,
@@ -6140,7 +6143,7 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi
 	case NETDEV_CHANGELOWERSTATE:
 	case NETDEV_CHANGE_TX_QUEUE_LEN:
 		rtmsg_ifinfo_event(RTM_NEWLINK, dev, 0, rtnl_get_event(event),
-				   GFP_KERNEL, NULL, 0);
+				   GFP_KERNEL, NULL, 0, 0, NULL);
 		break;
 	default:
 		break;

net/ipv4/ip_gre.c

@@ -1665,7 +1665,7 @@ struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 	if (err)
 		goto out;
 
-	err = rtnl_configure_link(dev, NULL);
+	err = rtnl_configure_link(dev, NULL, 0, NULL);
 	if (err < 0)
 		goto out;