Not only it was improperly use to queue backlogged RX skbuffs, but it was
also not processed at all.
If the socket receive queue is full we simply drop the incoming packets.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

NFC_CMD_LLC_GET_PARAMS: request LTO, RW, and MIUX parameters for a device

NFC_CMD_LLC_SET_PARAMS: set one or more of LTO, RW, and MIUX parameters for
a device. LTO must be set before the link is up otherwise -EINPROGRESS is
returned. RW and MIUX can be set at anytime and will be passed in subsequent
CONNECT and CC messages. If one of the passed parameters is wrong none is
set and -EINVAL is returned.
Signed-off-by: NThierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

UI frames still need to follow the MIU rule, and they need to use the
client passed dsap as the listening socket dsap is stuck on SDP.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

UI (Unnumbered Information) frames are used for sending data over
connection less links.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

SNL (Service Name Lookup) frames are used to respond to SNL requests.
This is needed for SDP implementation.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

This adds support for socket of type SOCK_RAW to LLCP.
sk_buff are copied and sent to raw sockets with a 2 bytes extra header:
The first byte header contains the nfc adapter index.
The second one contains flags:
- 0x01 - Direction (0=RX, 1=TX)
- 0x02-0x80 - Reserved
A raw socket has to be explicitly bound to a nfc adapter. This is achieved
by specifying the adapter index to be bound to in the dev_idx field of the
sockaddr_nfc_llcp struct passed to bind().
Signed-off-by: NThierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

NFC is using a number of custom ordered workqueues w/ WQ_MEM_RECLAIM.
WQ_MEM_RECLAIM is unnecessary unless NFC is gonna be used as transport
for storage device, and all use cases match one work item to one
ordered workqueue - IOW, there's no actual ordering going on at all
and using system_nrt_wq gives the same behavior.

There's nothing to be gained by using custom workqueues.  Use
system_nrt_wq instead and drop all the custom ones.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

With the LLCP 16 local SAPs we can potentially quickly run out of source
SAPs for non well known services.
With the so called late binding we will reserve an SAP only when we actually
get a client connection for a local service. The SAP will be released once
the last client is gone, leaving it available to other services.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The LLCP SAP should only be freed when the socket owning it is released.
As long as the socket is alive, the SAP should be reserved in order to
e.g. send the right wks array when bringing the MAC up.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The MIU extension value can be received during the PAX or during the
connection establishment process. It's definitely a connection related value
rather than a link one.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

RW can only be fetched from a CONNECT or a CC frame thus making it an
end points specific value, not a link one.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Simplify the LLCP sockets structure by putting all the connected ones
into a single linked list.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

LLCP sockets point to their local LLCP service, so they need to take a
reference on it.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We use the maximum values for the LLCP Maximum Information Unit and Receive
Window Size.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In order to acknowledge an I frame, we have to either queue pending local
I frames or queue a receiver ready frame.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This one will be called from the I frame command sending.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch is an initial implementation for the NFC Logical Link Control
protocol. It's also known as NFC peer to peer mode.
This is a basic implementation as it lacks SDP (services Discovery
Protocol), frames aggregation support, and frame rejecion parsing.
Follow up patches will implement those missing features.
This code has been tested against a Nexus S phone implementing LLCP 1.0.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>