Merge branch 'rtnetlink-Updates-to-rtnetlink_event'

Vladislav Yasevich says:

====================
rtnetlink: Updates to rtnetlink_event()

First is the patch to add IFLA_EVENT attribute to the netlink message.  It
supports only currently white-listed events.
Like before, this is just an attribute that gets added to the rtnetlink
message only when the messaged was generated as a result of a netdev event.
In my case, this is necessary since I want to trap NETDEV_NOTIFY_PEERS
event (also possibly NETDEV_RESEND_IGMP event) and perform certain actions
in user space.  This is not possible since the messages generated as
a result of netdev events do not usually contain any changed data.  They
are just notifications.  This patch exposes this notification type to
userspace.

Second, I remove duplicate messages that a result of a change to bonding
options.  If netlink is used to configure bonding options, 2 messages
are generated, one as a result NETDEV_CHANGEINFODATA event triggered by
bonding code and one a result of device state changes triggered by
netdev_state_change (called from do_setlink).

V6: Updated names and refactored to make it less tied to netdev events.
    (From David Ahern)
V5: Rebased.  Added iproute2 patch to the series.
V4:
  * Removed the patch the removed NETDEV_CHANGENAME from event whitelist.
    It doesn't trigger duplicate messages since name changes can only be
    done while device is down and netdev_state_change() doesn't report
    changes while device is down.
  * Added a patch to clean-up duplicate messages on bonding option changes.

V3: Rebased.  Cleaned-up duplicate event.

V2: Added missed events (from David Ahern)
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_main.c

@@ -3488,7 +3488,8 @@ static int bond_do_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cmd
 	case BOND_CHANGE_ACTIVE_OLD:
 	case SIOCBONDCHANGEACTIVE:
 		bond_opt_initstr(&newval, slave_dev->name);
-		res = __bond_opt_set(bond, BOND_OPT_ACTIVE_SLAVE, &newval);
+		res = __bond_opt_set_notify(bond, BOND_OPT_ACTIVE_SLAVE,
+					    &newval);
 		break;
 	default:
 		res = -EOPNOTSUPP;

drivers/net/bonding/bond_options.c

@@ -673,7 +673,30 @@ int __bond_opt_set(struct bonding *bond,
 out:
 	if (ret)
 		bond_opt_error_interpret(bond, opt, ret, val);
-	else if (bond->dev->reg_state == NETREG_REGISTERED)
+
+	return ret;
+}
+/**
+ * __bond_opt_set_notify - set a bonding option
+ * @bond: target bond device
+ * @option: option to set
+ * @val: value to set it to
+ *
+ * This function is used to change the bond's option value and trigger
+ * a notification to user sapce. It can be used for both enabling/changing
+ * an option and for disabling it. RTNL lock must be obtained before calling
+ * this function.
+ */
+int __bond_opt_set_notify(struct bonding *bond,
+			  unsigned int option, struct bond_opt_value *val)
+{
+	int ret = -ENOENT;
+
+	ASSERT_RTNL();
+
+	ret = __bond_opt_set(bond, option, val);
+
+	if (!ret && (bond->dev->reg_state == NETREG_REGISTERED))
 		call_netdevice_notifiers(NETDEV_CHANGEINFODATA, bond->dev);
 
 	return ret;
@@ -696,7 +719,7 @@ int bond_opt_tryset_rtnl(struct bonding *bond, unsigned int option, char *buf)
 	if (!rtnl_trylock())
 		return restart_syscall();
 	bond_opt_initstr(&optval, buf);
-	ret = __bond_opt_set(bond, option, &optval);
+	ret = __bond_opt_set_notify(bond, option, &optval);
 	rtnl_unlock();
 
 	return ret;

include/linux/rtnetlink.h

@@ -18,7 +18,8 @@ extern int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst,
 
 void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change, gfp_t flags);
 struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
-				       unsigned change, gfp_t flags);
+				       unsigned change, u32 event,
+				       gfp_t flags);
 void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev,
 		       gfp_t flags);
 

include/net/bond_options.h

@@ -104,6 +104,8 @@ struct bond_option {
 
 int __bond_opt_set(struct bonding *bond, unsigned int option,
 		   struct bond_opt_value *val);
+int __bond_opt_set_notify(struct bonding *bond, unsigned int option,
+			  struct bond_opt_value *val);
 int bond_opt_tryset_rtnl(struct bonding *bond, unsigned int option, char *buf);
 
 const struct bond_opt_value *bond_opt_parse(const struct bond_option *opt,

include/uapi/linux/if_link.h

@@ -157,6 +157,7 @@ enum {
 	IFLA_GSO_MAX_SIZE,
 	IFLA_PAD,
 	IFLA_XDP,
+	IFLA_EVENT,
 	__IFLA_MAX
 };
 
@@ -911,4 +912,14 @@ enum {
 
 #define IFLA_XDP_MAX (__IFLA_XDP_MAX - 1)
 
+enum {
+	IFLA_EVENT_NONE,
+	IFLA_EVENT_REBOOT,		/* internal reset / reboot */
+	IFLA_EVENT_FEATURES,		/* change in offload features */
+	IFLA_EVENT_BONDING_FAILOVER,	/* change in active slave */
+	IFLA_EVENT_NOTIFY_PEERS,	/* re-sent grat. arp/ndisc */
+	IFLA_EVENT_IGMP_RESEND,		/* re-sent IGMP JOIN */
+	IFLA_EVENT_BONDING_OPTIONS,	/* change in bonding options */
+};
+
 #endif /* _UAPI_LINUX_IF_LINK_H */

net/core/dev.c

@@ -7084,7 +7084,7 @@ static void rollback_registered_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,
+			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
 						     GFP_KERNEL);
 
 		/*

net/core/rtnetlink.c

@@ -941,6 +941,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
 	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_SWITCH_ID */
 	       + nla_total_size(IFNAMSIZ) /* IFLA_PHYS_PORT_NAME */
 	       + rtnl_xdp_size() /* IFLA_XDP */
+	       + nla_total_size(4)  /* IFLA_EVENT */
 	       + nla_total_size(1); /* IFLA_PROTO_DOWN */
 
 }
@@ -1282,9 +1283,40 @@ static int rtnl_xdp_fill(struct sk_buff *skb, struct net_device *dev)
 	return err;
 }
 
+static u32 rtnl_get_event(unsigned long event)
+{
+	u32 rtnl_event_type = IFLA_EVENT_NONE;
+
+	switch (event) {
+	case NETDEV_REBOOT:
+		rtnl_event_type = IFLA_EVENT_REBOOT;
+		break;
+	case NETDEV_FEAT_CHANGE:
+		rtnl_event_type = IFLA_EVENT_FEATURES;
+		break;
+	case NETDEV_BONDING_FAILOVER:
+		rtnl_event_type = IFLA_EVENT_BONDING_FAILOVER;
+		break;
+	case NETDEV_NOTIFY_PEERS:
+		rtnl_event_type = IFLA_EVENT_NOTIFY_PEERS;
+		break;
+	case NETDEV_RESEND_IGMP:
+		rtnl_event_type = IFLA_EVENT_IGMP_RESEND;
+		break;
+	case NETDEV_CHANGEINFODATA:
+		rtnl_event_type = IFLA_EVENT_BONDING_OPTIONS;
+		break;
+	default:
+		break;
+	}
+
+	return rtnl_event_type;
+}
+
 static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
 			    int type, u32 pid, u32 seq, u32 change,
-			    unsigned int flags, u32 ext_filter_mask)
+			    unsigned int flags, u32 ext_filter_mask,
+			    u32 event)
 {
 	struct ifinfomsg *ifm;
 	struct nlmsghdr *nlh;
@@ -1333,6 +1365,11 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
 	    nla_put_u8(skb, IFLA_PROTO_DOWN, dev->proto_down))
 		goto nla_put_failure;
 
+	if (event != IFLA_EVENT_NONE) {
+		if (nla_put_u32(skb, IFLA_EVENT, event))
+			goto nla_put_failure;
+	}
+
 	if (rtnl_fill_link_ifmap(skb, dev))
 		goto nla_put_failure;
 
@@ -1467,6 +1504,7 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
 	[IFLA_LINK_NETNSID]	= { .type = NLA_S32 },
 	[IFLA_PROTO_DOWN]	= { .type = NLA_U8 },
 	[IFLA_XDP]		= { .type = NLA_NESTED },
+	[IFLA_EVENT]		= { .type = NLA_U32 },
 };
 
 static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
@@ -1626,7 +1664,7 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 					       NETLINK_CB(cb->skb).portid,
 					       cb->nlh->nlmsg_seq, 0,
 					       flags,
-					       ext_filter_mask);
+					       ext_filter_mask, 0);
 
 			if (err < 0) {
 				if (likely(skb->len))
@@ -2736,7 +2774,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh,
 		return -ENOBUFS;
 
 	err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).portid,
-			       nlh->nlmsg_seq, 0, 0, ext_filter_mask);
+			       nlh->nlmsg_seq, 0, 0, ext_filter_mask, 0);
 	if (err < 0) {
 		/* -EMSGSIZE implies BUG in if_nlmsg_size */
 		WARN_ON(err == -EMSGSIZE);
@@ -2808,7 +2846,8 @@ 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, gfp_t flags)
+				       unsigned int change,
+				       u32 event, gfp_t flags)
 {
 	struct net *net = dev_net(dev);
 	struct sk_buff *skb;
@@ -2819,7 +2858,7 @@ struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
 	if (skb == NULL)
 		goto errout;
 
-	err = rtnl_fill_ifinfo(skb, dev, type, 0, 0, change, 0, 0);
+	err = rtnl_fill_ifinfo(skb, dev, type, 0, 0, change, 0, 0, event);
 	if (err < 0) {
 		/* -EMSGSIZE implies BUG in if_nlmsg_size() */
 		WARN_ON(err == -EMSGSIZE);
@@ -2840,7 +2879,8 @@ void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev, gfp_t flags)
 	rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, flags);
 }
 
-void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change,
+static void rtmsg_ifinfo_event(int type, struct net_device *dev,
+			       unsigned int change, u32 event,
 			       gfp_t flags)
 {
 	struct sk_buff *skb;
@@ -2848,10 +2888,16 @@ void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change,
 	if (dev->reg_state != NETREG_REGISTERED)
 		return;
 
-	skb = rtmsg_ifinfo_build_skb(type, dev, change, flags);
+	skb = rtmsg_ifinfo_build_skb(type, dev, change, event, flags);
 	if (skb)
 		rtmsg_ifinfo_send(skb, dev, flags);
 }
+
+void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change,
+		  gfp_t flags)
+{
+	rtmsg_ifinfo_event(type, dev, change, IFLA_EVENT_NONE, flags);
+}
 EXPORT_SYMBOL(rtmsg_ifinfo);
 
 static int nlmsg_populate_fdb_fill(struct sk_buff *skb,
@@ -4168,7 +4214,8 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi
 	case NETDEV_NOTIFY_PEERS:
 	case NETDEV_RESEND_IGMP:
 	case NETDEV_CHANGEINFODATA:
-		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
+		rtmsg_ifinfo_event(RTM_NEWLINK, dev, 0, rtnl_get_event(event),
+				   GFP_KERNEL);
 		break;
 	default:
 		break;