[PATCH] netdev: generate kobject uevent on network events.

[PATCH] netdev: generate kobject uevent on network events.

[Stephen Hemminger]

It is easier for some applications to deal with text based interfaces
like uevent, rather than using netlink to listen for events.

Note, this does not deal with network namespaces but that is a generic
problem that already exists with kobjects (see rename events).

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>

---
 net/core/Makefile |    1 
 net/core/uevent.c |   61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

--- a/net/core/Makefile	2008-11-24 08:40:10.000000000 -0800
+++ b/net/core/Makefile	2008-11-24 08:51:01.000000000 -0800
@@ -17,3 +17,4 @@ obj-$(CONFIG_NET_PKTGEN) += pktgen.o
 obj-$(CONFIG_NETPOLL) += netpoll.o
 obj-$(CONFIG_NET_DMA) += user_dma.o
 obj-$(CONFIG_FIB_RULES) += fib_rules.o
+obj-$(CONFIG_HOTPLUG) += uevent.o
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ b/net/core/uevent.c	2008-11-24 09:06:50.000000000 -0800
@@ -0,0 +1,60 @@
+/*
+ * Linux network device event notification
+ *
+ * Author:
+ *	Stephen Hemminger <shemminger@vyatta.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/kobject.h>
+#include <linux/notifier.h>
+
+/*
+ * Generate uevent in response to nework device changes.
+ * NB: KOBJ_MOVE is already genereated by kobject_rename
+ */
+static int netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+	struct net_device *netdev = ptr;
+
+	switch (event) {
+	case NETDEV_UNREGISTER:
+		kobject_uevent(&netdev->dev.kobj, KOBJ_REMOVE);
+		break;
+	case NETDEV_REGISTER:
+		kobject_uevent(&netdev->dev.kobj, KOBJ_ADD);
+		break;
+	case NETDEV_UP:
+		kobject_uevent(&netdev->dev.kobj, KOBJ_ONLINE);
+		break;
+	case NETDEV_DOWN:
+		kobject_uevent(&netdev->dev.kobj, KOBJ_OFFLINE);
+		break;
+	case NETDEV_CHANGE:
+		if (netif_running(netdev)) {
+			char str[64] = "DEVSTATE=UP";
+			char *envp[2] = { str, NULL };
+
+			if (netif_oper_up(netdev))
+				strcat(str, ",RUNNING");
+			if (netif_carrier_ok(netdev))
+				strcat(str, ",LOWER_UP");
+			if (netif_dormant(netdev))
+				strcat(str, ",DORMANT");
+			kobject_uevent_env(&netdev->dev.kobj, KOBJ_CHANGE, envp);
+		}
+		break;
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block netdev_uevent_notifier = {
+	.notifier_call	= netdev_event,
+};
+
+static int __init netdev_uevent_init(void)
+{
+	return register_netdevice_notifier(&netdev_uevent_notifier);
+}
+device_initcall(netdev_uevent_init);

Re: [PATCH] netdev: generate kobject uevent on network events.

[Kay Sievers]

On Mon, Nov 24, 2008 at 20:45, Stephen Hemminger <shemminger@vyatta.com> wrote:
> It is easier for some applications to deal with text based interfaces
> like uevent, rather than using netlink to listen for events.
>
> Note, this does not deal with network namespaces but that is a generic
> problem that already exists with kobjects (see rename events).
>
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
>
> ---
>  net/core/Makefile |    1
>  net/core/uevent.c |   61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 62 insertions(+)
>
> --- a/net/core/Makefile 2008-11-24 08:40:10.000000000 -0800
> +++ b/net/core/Makefile 2008-11-24 08:51:01.000000000 -0800
> @@ -17,3 +17,4 @@ obj-$(CONFIG_NET_PKTGEN) += pktgen.o
>  obj-$(CONFIG_NETPOLL) += netpoll.o
>  obj-$(CONFIG_NET_DMA) += user_dma.o
>  obj-$(CONFIG_FIB_RULES) += fib_rules.o
> +obj-$(CONFIG_HOTPLUG) += uevent.o
> --- /dev/null   1970-01-01 00:00:00.000000000 +0000
> +++ b/net/core/uevent.c 2008-11-24 09:06:50.000000000 -0800
> @@ -0,0 +1,60 @@
> +/*
> + * Linux network device event notification
> + *
> + * Author:
> + *     Stephen Hemminger <shemminger@vyatta.com>
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/netdevice.h>
> +#include <linux/kobject.h>
> +#include <linux/notifier.h>
> +
> +/*
> + * Generate uevent in response to nework device changes.
> + * NB: KOBJ_MOVE is already genereated by kobject_rename
> + */
> +static int netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
> +{
> +       struct net_device *netdev = ptr;
> +
> +       switch (event) {
> +       case NETDEV_UNREGISTER:
> +               kobject_uevent(&netdev->dev.kobj, KOBJ_REMOVE);
> +               break;
> +       case NETDEV_REGISTER:
> +               kobject_uevent(&netdev->dev.kobj, KOBJ_ADD);
> +               break;

Did you do anything else to prevent the duplicated add/remove events?
The core does send these already. I replied with a "udevadm monitor"
output to your earlier mail. Don't you see the duplicates on your box?

Thanks,
Kay

Re: [PATCH] netdev: generate kobject uevent on network events.

[Ben Hutchings]

On Mon, 2008-11-24 at 11:45 -0800, Stephen Hemminger wrote:
[...]
> +	case NETDEV_CHANGE:
> +		if (netif_running(netdev)) {
> +			char str[64] = "DEVSTATE=UP";
> +			char *envp[2] = { str, NULL };
> +
> +			if (netif_oper_up(netdev))
> +				strcat(str, ",RUNNING");
> +			if (netif_carrier_ok(netdev))
> +				strcat(str, ",LOWER_UP");
> +			if (netif_dormant(netdev))
> +				strcat(str, ",DORMANT");
> +			kobject_uevent_env(&netdev->dev.kobj, KOBJ_CHANGE, envp);
> +		}
> +		break;

Unless I'm much mistaken, NETDEV_CHANGE should only be generated when
netif_running() is true, so the test is redundant.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

Re: [PATCH] netdev: generate kobject uevent on network events.

[Stephen Hemminger]

On Mon, 24 Nov 2008 20:55:02 +0100
"Kay Sievers" <kay.sievers@vrfy.org> wrote:

> On Mon, Nov 24, 2008 at 20:45, Stephen Hemminger <shemminger@vyatta.com> wrote:
> > It is easier for some applications to deal with text based interfaces
> > like uevent, rather than using netlink to listen for events.
> >
> > Note, this does not deal with network namespaces but that is a generic
> > problem that already exists with kobjects (see rename events).
> >
> > Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
> >
> > ---
> >  net/core/Makefile |    1
> >  net/core/uevent.c |   61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 62 insertions(+)
> >
> > --- a/net/core/Makefile 2008-11-24 08:40:10.000000000 -0800
> > +++ b/net/core/Makefile 2008-11-24 08:51:01.000000000 -0800
> > @@ -17,3 +17,4 @@ obj-$(CONFIG_NET_PKTGEN) += pktgen.o
> >  obj-$(CONFIG_NETPOLL) += netpoll.o
> >  obj-$(CONFIG_NET_DMA) += user_dma.o
> >  obj-$(CONFIG_FIB_RULES) += fib_rules.o
> > +obj-$(CONFIG_HOTPLUG) += uevent.o
> > --- /dev/null   1970-01-01 00:00:00.000000000 +0000
> > +++ b/net/core/uevent.c 2008-11-24 09:06:50.000000000 -0800
> > @@ -0,0 +1,60 @@
> > +/*
> > + * Linux network device event notification
> > + *
> > + * Author:
> > + *     Stephen Hemminger <shemminger@vyatta.com>
> > + */
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/netdevice.h>
> > +#include <linux/kobject.h>
> > +#include <linux/notifier.h>
> > +
> > +/*
> > + * Generate uevent in response to nework device changes.
> > + * NB: KOBJ_MOVE is already genereated by kobject_rename
> > + */
> > +static int netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
> > +{
> > +       struct net_device *netdev = ptr;
> > +
> > +       switch (event) {
> > +       case NETDEV_UNREGISTER:
> > +               kobject_uevent(&netdev->dev.kobj, KOBJ_REMOVE);
> > +               break;
> > +       case NETDEV_REGISTER:
> > +               kobject_uevent(&netdev->dev.kobj, KOBJ_ADD);
> > +               break;
> 
> Did you do anything else to prevent the duplicated add/remove events?
> The core does send these already. I replied with a "udevadm monitor"
> output to your earlier mail. Don't you see the duplicates on your box?
> 
> Thanks,
> Kay

okay, then i'll just take it out of here.

[PATCH] netdev: generate kobject uevent on network state transitions

[Stephen Hemminger]

It is easier for some applications to deal with text based interfaces
like uevent, rather than using netlink to listen for events.

Note, this does not deal with network namespaces but that is a generic
problem that already exists with kobjects (see rename events).

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>

---
 net/core/Makefile |    1 
 net/core/uevent.c |   61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

--- a/net/core/Makefile	2008-11-24 12:07:18.000000000 -0800
+++ b/net/core/Makefile	2008-11-24 12:07:22.000000000 -0800
@@ -17,3 +17,4 @@ obj-$(CONFIG_NET_PKTGEN) += pktgen.o
 obj-$(CONFIG_NETPOLL) += netpoll.o
 obj-$(CONFIG_NET_DMA) += user_dma.o
 obj-$(CONFIG_FIB_RULES) += fib_rules.o
+obj-$(CONFIG_HOTPLUG) += uevent.o
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ b/net/core/uevent.c	2008-11-24 12:11:46.000000000 -0800
@@ -0,0 +1,55 @@
+/*
+ * Linux network device event notification
+ *
+ * Author:
+ *	Stephen Hemminger <shemminger@vyatta.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/kobject.h>
+#include <linux/notifier.h>
+
+/*
+ * Generate uevent in response to network device state changes.
+ * Other events are already handled by device subsystem.
+ */
+static int netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+	struct net_device *netdev = ptr;
+
+	switch (event) {
+	case NETDEV_UP:
+		kobject_uevent(&netdev->dev.kobj, KOBJ_ONLINE);
+		break;
+
+	case NETDEV_DOWN:
+		kobject_uevent(&netdev->dev.kobj, KOBJ_OFFLINE);
+		break;
+
+	case NETDEV_CHANGE: {
+		char str[64] = "DEVSTATE=UP";
+		char *envp[2] = { str, NULL };
+
+		if (netif_oper_up(netdev))
+			strcat(str, ",RUNNING");
+		if (netif_carrier_ok(netdev))
+			strcat(str, ",LOWER_UP");
+		if (netif_dormant(netdev))
+			strcat(str, ",DORMANT");
+		kobject_uevent_env(&netdev->dev.kobj, KOBJ_CHANGE, envp);
+		break;
+		}
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block netdev_uevent_notifier = {
+	.notifier_call	= netdev_event,
+};
+
+static int __init netdev_uevent_init(void)
+{
+	return register_netdevice_notifier(&netdev_uevent_notifier);
+}
+device_initcall(netdev_uevent_init);

Re: [PATCH] netdev: generate kobject uevent on network state transitions

[Kay Sievers]

On Tue, Nov 25, 2008 at 00:03, Stephen Hemminger <shemminger@vyatta.com> wrote:
> It is easier for some applications to deal with text based interfaces
> like uevent, rather than using netlink to listen for events.
>
> Note, this does not deal with network namespaces but that is a generic
> problem that already exists with kobjects (see rename events).
>
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>

Works fine here.

Thanks,
Kay

Re: [PATCH] netdev: generate kobject uevent on network state transitions

[Marcel Holtmann]

Hi Stephen,

> It is easier for some applications to deal with text based interfaces
> like uevent, rather than using netlink to listen for events.
>
> Note, this does not deal with network namespaces but that is a generic
> problem that already exists with kobjects (see rename events).
>
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
>
> ---
> net/core/Makefile |    1
> net/core/uevent.c |   61 ++++++++++++++++++++++++++++++++++++++++++++ 
> ++++++++++
> 2 files changed, 62 insertions(+)
>
> --- a/net/core/Makefile	2008-11-24 12:07:18.000000000 -0800
> +++ b/net/core/Makefile	2008-11-24 12:07:22.000000000 -0800
> @@ -17,3 +17,4 @@ obj-$(CONFIG_NET_PKTGEN) += pktgen.o
> obj-$(CONFIG_NETPOLL) += netpoll.o
> obj-$(CONFIG_NET_DMA) += user_dma.o
> obj-$(CONFIG_FIB_RULES) += fib_rules.o
> +obj-$(CONFIG_HOTPLUG) += uevent.o
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ b/net/core/uevent.c	2008-11-24 12:11:46.000000000 -0800
> @@ -0,0 +1,55 @@
> +/*
> + * Linux network device event notification
> + *
> + * Author:
> + *	Stephen Hemminger <shemminger@vyatta.com>
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/netdevice.h>
> +#include <linux/kobject.h>
> +#include <linux/notifier.h>
> +
> +/*
> + * Generate uevent in response to network device state changes.
> + * Other events are already handled by device subsystem.
> + */
> +static int netdev_event(struct notifier_block *this, unsigned long  
> event, void *ptr)
> +{
> +	struct net_device *netdev = ptr;
> +
> +	switch (event) {
> +	case NETDEV_UP:
> +		kobject_uevent(&netdev->dev.kobj, KOBJ_ONLINE);
> +		break;
> +
> +	case NETDEV_DOWN:
> +		kobject_uevent(&netdev->dev.kobj, KOBJ_OFFLINE);
> +		break;
> +
> +	case NETDEV_CHANGE: {
> +		char str[64] = "DEVSTATE=UP";
> +		char *envp[2] = { str, NULL };
> +
> +		if (netif_oper_up(netdev))
> +			strcat(str, ",RUNNING");
> +		if (netif_carrier_ok(netdev))
> +			strcat(str, ",LOWER_UP");
> +		if (netif_dormant(netdev))
> +			strcat(str, ",DORMANT");
> +		kobject_uevent_env(&netdev->dev.kobj, KOBJ_CHANGE, envp);
> +		break;

do we wanna copy just what ifconfig shows or do we might be a more  
intelligent and have separate variables like RUNNING=1 etc.?

Regards

Marcel

Re: [PATCH] netdev: generate kobject uevent on network state transitions

[Stephen Hemminger]

On Tue, 25 Nov 2008 04:51:53 +0100
Marcel Holtmann <marcel@holtmann.org> wrote:

> Hi Stephen,
> 
> > It is easier for some applications to deal with text based interfaces
> > like uevent, rather than using netlink to listen for events.
> >
> > Note, this does not deal with network namespaces but that is a generic
> > problem that already exists with kobjects (see rename events).
> >
> > Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
> >
> > ---
> > net/core/Makefile |    1
> > net/core/uevent.c |   61 ++++++++++++++++++++++++++++++++++++++++++++ 
> > ++++++++++
> > 2 files changed, 62 insertions(+)
> >
> > --- a/net/core/Makefile	2008-11-24 12:07:18.000000000 -0800
> > +++ b/net/core/Makefile	2008-11-24 12:07:22.000000000 -0800
> > @@ -17,3 +17,4 @@ obj-$(CONFIG_NET_PKTGEN) += pktgen.o
> > obj-$(CONFIG_NETPOLL) += netpoll.o
> > obj-$(CONFIG_NET_DMA) += user_dma.o
> > obj-$(CONFIG_FIB_RULES) += fib_rules.o
> > +obj-$(CONFIG_HOTPLUG) += uevent.o
> > --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> > +++ b/net/core/uevent.c	2008-11-24 12:11:46.000000000 -0800
> > @@ -0,0 +1,55 @@
> > +/*
> > + * Linux network device event notification
> > + *
> > + * Author:
> > + *	Stephen Hemminger <shemminger@vyatta.com>
> > + */
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/netdevice.h>
> > +#include <linux/kobject.h>
> > +#include <linux/notifier.h>
> > +
> > +/*
> > + * Generate uevent in response to network device state changes.
> > + * Other events are already handled by device subsystem.
> > + */
> > +static int netdev_event(struct notifier_block *this, unsigned long  
> > event, void *ptr)
> > +{
> > +	struct net_device *netdev = ptr;
> > +
> > +	switch (event) {
> > +	case NETDEV_UP:
> > +		kobject_uevent(&netdev->dev.kobj, KOBJ_ONLINE);
> > +		break;
> > +
> > +	case NETDEV_DOWN:
> > +		kobject_uevent(&netdev->dev.kobj, KOBJ_OFFLINE);
> > +		break;
> > +
> > +	case NETDEV_CHANGE: {
> > +		char str[64] = "DEVSTATE=UP";
> > +		char *envp[2] = { str, NULL };
> > +
> > +		if (netif_oper_up(netdev))
> > +			strcat(str, ",RUNNING");
> > +		if (netif_carrier_ok(netdev))
> > +			strcat(str, ",LOWER_UP");
> > +		if (netif_dormant(netdev))
> > +			strcat(str, ",DORMANT");
> > +		kobject_uevent_env(&netdev->dev.kobj, KOBJ_CHANGE, envp);
> > +		break;
> 
> do we wanna copy just what ifconfig shows or do we might be a more  
> intelligent and have separate variables like RUNNING=1 etc.?
> 
> Regards
> 
> Marcel

Was arbitrary choice to just use same flags as existing ifconfig.
What ever feels best I guess...

Re: [PATCH] netdev: generate kobject uevent on network events.

[David Miller]

From: Stephen Hemminger <shemminger@vyatta.com>
Date: Mon, 24 Nov 2008 12:06:45 -0800

> On Mon, 24 Nov 2008 20:55:02 +0100
> "Kay Sievers" <kay.sievers@vrfy.org> wrote:
> 
> > Did you do anything else to prevent the duplicated add/remove events?
> > The core does send these already. I replied with a "udevadm monitor"
> > output to your earlier mail. Don't you see the duplicates on your box?
> > 
> > Thanks,
> > Kay
> 
> okay, then i'll just take it out of here.

I'll wait for the updated patch then.

Re: [PATCH] netdev: generate kobject uevent on network state transitions

[David Miller]

From: Stephen Hemminger <shemminger@vyatta.com>
Date: Mon, 24 Nov 2008 20:14:40 -0800

> On Tue, 25 Nov 2008 04:51:53 +0100
> Marcel Holtmann <marcel@holtmann.org> wrote:
> 
> > > It is easier for some applications to deal with text based interfaces
> > > like uevent, rather than using netlink to listen for events.
> > >
> > > Note, this does not deal with network namespaces but that is a generic
> > > problem that already exists with kobjects (see rename events).
> > >
> > > Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
 ...
> > do we wanna copy just what ifconfig shows or do we might be a more  
> > intelligent and have separate variables like RUNNING=1 etc.?
> 
> Was arbitrary choice to just use same flags as existing ifconfig.
> What ever feels best I guess...

So what do folks want me to do here?  Should I put Stephen's
latest patch in, or do we want to make some kind of flags change?

Re: [PATCH] netdev: generate kobject uevent on network state transitions

[Marcel Holtmann]

Hi Dave,

>>>> It is easier for some applications to deal with text based  
>>>> interfaces
>>>> like uevent, rather than using netlink to listen for events.
>>>>
>>>> Note, this does not deal with network namespaces but that is a  
>>>> generic
>>>> problem that already exists with kobjects (see rename events).
>>>>
>>>> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
> ...
>>> do we wanna copy just what ifconfig shows or do we might be a more
>>> intelligent and have separate variables like RUNNING=1 etc.?
>>
>> Was arbitrary choice to just use same flags as existing ifconfig.
>> What ever feels best I guess...
>
> So what do folks want me to do here?  Should I put Stephen's
> latest patch in, or do we want to make some kind of flags change?

I am thinking of using per value variables. My personal choice.

Kay, any pointers or opinions from you?

Regards

Marcel

Re: [PATCH] netdev: generate kobject uevent on network state transitions

[Kay Sievers]

On Wed, Nov 26, 2008 at 06:24, Marcel Holtmann <marcel@holtmann.org> wrote:
>>>>> It is easier for some applications to deal with text based interfaces
>>>>> like uevent, rather than using netlink to listen for events.
>>>>>
>>>>> Note, this does not deal with network namespaces but that is a generic
>>>>> problem that already exists with kobjects (see rename events).
>>>>>
>>>>> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
>> ...
>>>> do we wanna copy just what ifconfig shows or do we might be a more
>>>> intelligent and have separate variables like RUNNING=1 etc.?
>>>
>>> Was arbitrary choice to just use same flags as existing ifconfig.
>>> What ever feels best I guess...
>>
>> So what do folks want me to do here?  Should I put Stephen's
>> latest patch in, or do we want to make some kind of flags change?
>
> I am thinking of using per value variables. My personal choice.
>
> Kay, any pointers or opinions from you?

As long as we can match values with fnmatch(), it should all work fine.

Bitmasks are fine if represented as binary strings, otherwise, like
for hex strings, the fnmatch() looks really weird.

As long as no string value in the list is contained in another value,
like matching for RUNNING, IS_RUNNING, RUNNING2 would be, it's fine to
stuff them all in one string just separated by comma. If they can ever
overlap, we would need to add the comma also to the beginning and end
of the string, to be able to put it into the match string like
"*,RUNNING,*", to avoid wrong matches by partial string matches.

I leave it up to you, I'm fighting with really weird things in some
other subsystems, so all of the possible options here for the net
events look pretty to me, and should work fine, compared to some stuff
I'm used to. :)

Thanks,
Kay