Commit def12888 authored by Vlad Yasevich's avatar Vlad Yasevich Committed by David S. Miller
Browse files

rtnl: Add support for netdev event to link messages 



When netdev events happen, a rtnetlink_event() handler will send
messages for every event in it's white list.  These messages contain
current information about a particular device, but they do not include
the iformation about which event just happened.  The consumer of
the message has to try to infer this information.  In some cases
(ex: NETDEV_NOTIFY_PEERS), that is not possible.

This patch adds a new extension to RTM_NEWLINK message called IFLA_EVENT
that would have an encoding of the which event triggered this
message.  This would allow the the message consumer to easily determine
if it is interested in a particular event or not.

Signed-off-by: default avatarVladislav Yasevich <vyasevic@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5138e86f

include/linux/rtnetlink.h

+2 −1
Original line number Diff line number Diff line
@@ -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, unsigned long event,

				       gfp_t flags);

void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev,

		       gfp_t flags);

include/uapi/linux/if_link.h

+21 −0
Original line number Diff line number Diff line
@@ -157,6 +157,7 @@ enum { 
	IFLA_GSO_MAX_SIZE,

	IFLA_PAD,

	IFLA_XDP,

	IFLA_EVENT,

	__IFLA_MAX

};
@@ -899,4 +900,24 @@ enum { 


#define IFLA_XDP_MAX (__IFLA_XDP_MAX - 1)



enum {

	IFLA_EVENT_UNSPEC,

	IFLA_EVENT_REBOOT,

	IFLA_EVENT_CHANGE_MTU,

	IFLA_EVENT_CHANGE_ADDR,

	IFLA_EVENT_CHANGE_NAME,

	IFLA_EVENT_FEAT_CHANGE,

	IFLA_EVENT_BONDING_FAILOVER,

	IFLA_EVENT_POST_TYPE_CHANGE,

	IFLA_EVENT_NOTIFY_PEERS,

	IFLA_EVENT_CHANGE_UPPER,

	IFLA_EVENT_RESEND_IGMP,

	IFLA_EVENT_PRE_CHANGE_MTU,

	IFLA_EVENT_CHANGE_INFO_DATA,

	IFLA_EVENT_PRE_CHANGE_UPPER,

	IFLA_EVENT_CHANGE_LOWER_STATE,

	IFLA_EVENT_UDP_TUNNEL_PUSH_INFO,

	IFLA_EVENT_CHANGE_TX_QUEUE_LEN,

};



#endif /* _UAPI_LINUX_IF_LINK_H */

net/core/dev.c

+1 −1
Original line number Diff line number Diff line
@@ -6840,7 +6840,7 @@ 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

+83 −9
Original line number Diff line number Diff line
@@ -944,6 +944,7 @@ 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(dev) /* IFLA_XDP */

	       + nla_total_size(4)  /* IFLA_EVENT */

	       + nla_total_size(1); /* IFLA_PROTO_DOWN */



}
@@ -1276,9 +1277,70 @@ err_cancel: 
	return err;

}



static int rtnl_fill_link_event(struct sk_buff *skb, unsigned long event)

{

	u32 rtnl_event;



	switch (event) {

	case NETDEV_REBOOT:

		rtnl_event = IFLA_EVENT_REBOOT;

		break;

	case NETDEV_CHANGEMTU:

		rtnl_event = IFLA_EVENT_CHANGE_MTU;

		break;

	case NETDEV_CHANGEADDR:

		rtnl_event = IFLA_EVENT_CHANGE_ADDR;

		break;

	case NETDEV_CHANGENAME:

		rtnl_event = IFLA_EVENT_CHANGE_NAME;

		break;

	case NETDEV_FEAT_CHANGE:

		rtnl_event = IFLA_EVENT_FEAT_CHANGE;

		break;

	case NETDEV_BONDING_FAILOVER:

		rtnl_event = IFLA_EVENT_BONDING_FAILOVER;

		break;

	case NETDEV_POST_TYPE_CHANGE:

		rtnl_event = IFLA_EVENT_POST_TYPE_CHANGE;

		break;

	case NETDEV_NOTIFY_PEERS:

		rtnl_event = IFLA_EVENT_NOTIFY_PEERS;

		break;

	case NETDEV_CHANGEUPPER:

		rtnl_event = IFLA_EVENT_CHANGE_UPPER;

		break;

	case NETDEV_RESEND_IGMP:

		rtnl_event = IFLA_EVENT_RESEND_IGMP;

		break;

	case NETDEV_PRECHANGEMTU:

		rtnl_event = IFLA_EVENT_PRE_CHANGE_MTU;

		break;

	case NETDEV_CHANGEINFODATA:

		rtnl_event = IFLA_EVENT_CHANGE_INFO_DATA;

		break;

	case NETDEV_PRECHANGEUPPER:

		rtnl_event = IFLA_EVENT_PRE_CHANGE_UPPER;

		break;

	case NETDEV_CHANGELOWERSTATE:

		rtnl_event = IFLA_EVENT_CHANGE_LOWER_STATE;

		break;

	case NETDEV_UDP_TUNNEL_PUSH_INFO:

		rtnl_event = IFLA_EVENT_UDP_TUNNEL_PUSH_INFO;

		break;

	case NETDEV_CHANGE_TX_QUEUE_LEN:

		rtnl_event = IFLA_EVENT_CHANGE_TX_QUEUE_LEN;

		break;

	default:

		return 0;

	}



	return nla_put_u32(skb, IFLA_EVENT, rtnl_event);

}



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,

			    unsigned long event)

{

	struct ifinfomsg *ifm;

	struct nlmsghdr *nlh;
@@ -1327,6 +1389,9 @@ 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 (rtnl_fill_link_event(skb, event))

		goto nla_put_failure;



	if (rtnl_fill_link_ifmap(skb, dev))

		goto nla_put_failure;
@@ -1461,6 +1526,7 @@ 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] = {
@@ -1619,7 +1685,7 @@ 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 we ran out of room on the first message,

			 * we're in trouble

			 */
@@ -2710,7 +2776,7 @@ 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);
@@ -2782,7 +2848,8 @@ 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,

				       unsigned long event, gfp_t flags)

{

	struct net *net = dev_net(dev);

	struct sk_buff *skb;
@@ -2793,7 +2860,7 @@ 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);
@@ -2814,7 +2881,8 @@ 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, unsigned long event,

			       gfp_t flags)

{

	struct sk_buff *skb;
@@ -2822,10 +2890,16 @@ 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, 0, flags);

}

EXPORT_SYMBOL(rtmsg_ifinfo);



static int nlmsg_populate_fdb_fill(struct sk_buff *skb,
@@ -4132,7 +4206,7 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi 
	case NETDEV_CHANGELOWERSTATE:

	case NETDEV_UDP_TUNNEL_PUSH_INFO:

	case NETDEV_CHANGE_TX_QUEUE_LEN:

		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);

		rtmsg_ifinfo_event(RTM_NEWLINK, dev, 0, event, GFP_KERNEL);

		break;

	default:

		break;

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