Query on usage of Netlink

[Kumar SANGHVI <kumar.sanghvi@stericsson.com>]

Hi All,

We have a requirement where-in we want to communicate the status of
modem (whether modem is online or offline) from linux driver to
user-space components. So that user-space components stop sending data
to linux driver for communicating with modem, in case modem goes
offline.

We have decided to use the netlink mechanism to achieve this. We intend
to send an integer value, defined in enum, to user-space indicating the
current modem status.

For this, we want to know what Netlink message type should we use?
Should we use some existing Netlink type? Will there be any risk of
getting other messages (the ones not sent by our driver) if using
existing Netlink message type? For e.g. if we use the existing type
NETLINK_ROUTE then, user-space may un-necessary receive netlink notification
for route changes.

Or should we define a custom Netlink type in include/linux/netlink.h?

Thank you for suggestions.

Best regards,
Kumar.