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.  So, it is impossible
to tell what just happend for these events.

This patch adds a new extension to RTM_NEWLINK message called IFLA_EVENT
that would have an encoding of event that triggered this
message.  This would allow the the message consumer to easily determine
if it needs to perform certain actions.

Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Vlad Yasevich
2017-05-27 10:14:34 -04:00
committed by David S. Miller
parent 34aa83c2fc
commit 3d3ea5af5c
4 changed files with 70 additions and 11 deletions

View File

@@ -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 @@ err_cancel:
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);
@@ -2840,18 +2879,25 @@ 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,
gfp_t flags)
static void rtmsg_ifinfo_event(int type, struct net_device *dev,
unsigned int change, u32 event,
gfp_t flags)
{
struct sk_buff *skb;
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;