wimax connection manager / daemon has to know what is current
state of the device. Previously it was only possible to get
notification whet state has changed.

Note:

 By mistake, the new generic netlink's number for
 WIMAX_GNL_OP_STATE_GET was declared inserting into the existing list
 of API calls, not appending; thus, it'd break existing API.

 Fixed by Inaky Perez-Gonzalez <inaky@linux.intel.com> by moving to
 the tail, where we add to the interface, not modify the interface.

 Thanks to Stephen Hemminger <shemminger@vyatta.com> for catching this.
Signed-off-by: NPaulius Zaleckas <paulius.zaleckas@teltonika.lt>

When a new wimax_dev is created, it's state has to be __WIMAX_ST_NULL
until wimax_dev_add() is succesfully called. This allows calls into
the stack that happen before said time to be rejected.

Until now, the state was being set (by mistake) to UNINITIALIZED,
which was allowing calls such as wimax_report_rfkill_hw() to go
through even when a call to wimax_dev_add() had failed; that was
causing an oops when touching uninitialized data.

This situation is normal when the device starts reporting state before
the whole initialization has been completed. It just has to be dealt
with.
Signed-off-by: NInaky Perez-Gonzalez <inaky@linux.intel.com>

Currently, netlink_broadcast() reports errors to the caller if no
messages at all were delivered:

1) If, at least, one message has been delivered correctly, returns 0.
2) Otherwise, if no messages at all were delivered due to skb_clone()
   failure, return -ENOBUFS.
3) Otherwise, if there are no listeners, return -ESRCH.

With this patch, the caller knows if the delivery of any of the
messages to the listeners have failed:

1) If it fails to deliver any message (for whatever reason), return
   -ENOBUFS.
2) Otherwise, if all messages were delivered OK, returns 0.
3) Otherwise, if no listeners, return -ESRCH.

In the current ctnetlink code and in Netfilter in general, we can add
reliable logging and connection tracking event delivery by dropping the
packets whose events were not successfully delivered over Netlink. Of
course, this option would be settable via /proc as this approach reduces
performance (in terms of filtered connections per seconds by a stateful
firewall) but providing reliable logging and event delivery (for
conntrackd) in return.

This patch also changes some clients of netlink_broadcast() that
may report ENOBUFS errors via printk. This error handling is not
of any help. Instead, the userspace daemons that are listening to
those netlink messages should resync themselves with the kernel-side
if they hit ENOBUFS.

BTW, netlink_broadcast() clients include those that call
cn_netlink_send(), nlmsg_multicast() and genlmsg_multicast() since they
internally call netlink_broadcast() and return its error value.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As reported by Toralf Förster and Randy Dunlap.

- http://linuxwimax.org/pipermail/wimax/2009-January/000460.html

- http://lkml.org/lkml/2009/1/29/279

The definitions needed for the wimax stack and i2400m driver debug
infrastructure was, by mistake, compiled depending on CONFIG_DEBUG_FS
(by them being placed in the debugfs.c files); thus the build broke in
2.6.29-rc3 when debugging was enabled (CONFIG_WIMAX_DEBUG) and
DEBUG_FS was disabled.

These definitions are always needed if debug is enabled at compile
time (independently of DEBUG_FS being or not enabled), so moving them
to a file that is always compiled fixes the issue.
Signed-off-by: NInaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implements the basic life cycles of a 'struct wimax_dev', some common
generic netlink functionality for marshalling calls to user space,
and the device state machine.

For looking up net devices based on their generic netlink family IDs,
use a low overhead method that optimizes for the case where most
systems have a single WiMAX device, or at most, a very low number of
WiMAX adaptors.
Signed-off-by: NInaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>