blob: 151f2ef429c4cf93708bdb6d1524ccf6f2b1cb55 [file] [log] [blame]
/*
* Copyright (C) 2011 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the
* Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#define pr_fmt(fmt) "llcp: %s: " fmt, __func__
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/nfc.h>
#include <net/nfc/nfc.h>
#include "../nfc.h"
#include "llcp.h"
static u8 llcp_tlv_length[LLCP_TLV_MAX] = {
0,
1, /* VERSION */
2, /* MIUX */
2, /* WKS */
1, /* LTO */
1, /* RW */
0, /* SN */
1, /* OPT */
0, /* SDREQ */
2, /* SDRES */
};
static u8 llcp_tlv8(u8 *tlv, u8 type)
{
if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
return 0;
return tlv[2];
}
static u8 llcp_tlv16(u8 *tlv, u8 type)
{
if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
return 0;
return be16_to_cpu(*((__be16 *)(tlv + 2)));
}
static u8 llcp_tlv_version(u8 *tlv)
{
return llcp_tlv8(tlv, LLCP_TLV_VERSION);
}
static u16 llcp_tlv_miux(u8 *tlv)
{
return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7f;
}
static u16 llcp_tlv_wks(u8 *tlv)
{
return llcp_tlv16(tlv, LLCP_TLV_WKS);
}
static u16 llcp_tlv_lto(u8 *tlv)
{
return llcp_tlv8(tlv, LLCP_TLV_LTO);
}
static u8 llcp_tlv_opt(u8 *tlv)
{
return llcp_tlv8(tlv, LLCP_TLV_OPT);
}
static u8 llcp_tlv_rw(u8 *tlv)
{
return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf;
}
u8 *nfc_llcp_build_tlv(u8 type, u8 *value, u8 value_length, u8 *tlv_length)
{
u8 *tlv, length;
pr_debug("type %d\n", type);
if (type >= LLCP_TLV_MAX)
return NULL;
length = llcp_tlv_length[type];
if (length == 0 && value_length == 0)
return NULL;
else
length = value_length;
*tlv_length = 2 + length;
tlv = kzalloc(2 + length, GFP_KERNEL);
if (tlv == NULL)
return tlv;
tlv[0] = type;
tlv[1] = length;
memcpy(tlv + 2, value, length);
return tlv;
}
int nfc_llcp_parse_tlv(struct nfc_llcp_local *local,
u8 *tlv_array, u16 tlv_array_len)
{
u8 *tlv = tlv_array, type, length, offset = 0;
pr_debug("TLV array length %d\n", tlv_array_len);
if (local == NULL)
return -ENODEV;
while (offset < tlv_array_len) {
type = tlv[0];
length = tlv[1];
pr_debug("type 0x%x length %d\n", type, length);
switch (type) {
case LLCP_TLV_VERSION:
local->remote_version = llcp_tlv_version(tlv);
break;
case LLCP_TLV_MIUX:
local->remote_miu = llcp_tlv_miux(tlv) + 128;
break;
case LLCP_TLV_WKS:
local->remote_wks = llcp_tlv_wks(tlv);
break;
case LLCP_TLV_LTO:
local->remote_lto = llcp_tlv_lto(tlv) * 10;
break;
case LLCP_TLV_OPT:
local->remote_opt = llcp_tlv_opt(tlv);
break;
case LLCP_TLV_RW:
local->remote_rw = llcp_tlv_rw(tlv);
break;
default:
pr_err("Invalid gt tlv value 0x%x\n", type);
break;
}
offset += length + 2;
tlv += length + 2;
}
pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x rw %d\n",
local->remote_version, local->remote_miu,
local->remote_lto, local->remote_opt,
local->remote_wks, local->remote_rw);
return 0;
}
static struct sk_buff *llcp_add_header(struct sk_buff *pdu,
u8 dsap, u8 ssap, u8 ptype)
{
u8 header[2];
pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
header[0] = (u8)((dsap << 2) | (ptype >> 2));
header[1] = (u8)((ptype << 6) | ssap);
pr_debug("header 0x%x 0x%x\n", header[0], header[1]);
memcpy(skb_put(pdu, LLCP_HEADER_SIZE), header, LLCP_HEADER_SIZE);
return pdu;
}
static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv, u8 tlv_length)
{
/* XXX Add an skb length check */
if (tlv == NULL)
return NULL;
memcpy(skb_put(pdu, tlv_length), tlv, tlv_length);
return pdu;
}
static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock,
u8 cmd, u16 size)
{
struct sk_buff *skb;
int err;
if (sock->ssap == 0)
return NULL;
skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
size + LLCP_HEADER_SIZE, &err);
if (skb == NULL) {
pr_err("Could not allocate PDU\n");
return NULL;
}
skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd);
return skb;
}
int nfc_llcp_disconnect(struct nfc_llcp_sock *sock)
{
struct sk_buff *skb;
struct nfc_dev *dev;
struct nfc_llcp_local *local;
u16 size = 0;
pr_debug("Sending DISC\n");
local = sock->local;
if (local == NULL)
return -ENODEV;
dev = sock->dev;
if (dev == NULL)
return -ENODEV;
size += LLCP_HEADER_SIZE;
size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
skb = alloc_skb(size, GFP_ATOMIC);
if (skb == NULL)
return -ENOMEM;
skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
skb = llcp_add_header(skb, sock->ssap, sock->dsap, LLCP_PDU_DISC);
skb_queue_tail(&local->tx_queue, skb);
return 0;
}
int nfc_llcp_send_symm(struct nfc_dev *dev)
{
struct sk_buff *skb;
struct nfc_llcp_local *local;
u16 size = 0;
pr_debug("Sending SYMM\n");
local = nfc_llcp_find_local(dev);
if (local == NULL)
return -ENODEV;
size += LLCP_HEADER_SIZE;
size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
skb = alloc_skb(size, GFP_KERNEL);
if (skb == NULL)
return -ENOMEM;
skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM);
return nfc_data_exchange(dev, local->target_idx, skb,
nfc_llcp_recv, local);
}
int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
{
struct nfc_llcp_local *local;
struct sk_buff *skb;
u8 *service_name_tlv = NULL, service_name_tlv_length;
int err;
u16 size = 0;
pr_debug("Sending CONNECT\n");
local = sock->local;
if (local == NULL)
return -ENODEV;
if (sock->service_name != NULL) {
service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN,
sock->service_name,
sock->service_name_len,
&service_name_tlv_length);
size += service_name_tlv_length;
}
pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len);
skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size);
if (skb == NULL) {
err = -ENOMEM;
goto error_tlv;
}
if (service_name_tlv != NULL)
skb = llcp_add_tlv(skb, service_name_tlv,
service_name_tlv_length);
skb_queue_tail(&local->tx_queue, skb);
return 0;
error_tlv:
pr_err("error %d\n", err);
kfree(service_name_tlv);
return err;
}
int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
{
struct nfc_llcp_local *local;
struct sk_buff *skb;
pr_debug("Sending CC\n");
local = sock->local;
if (local == NULL)
return -ENODEV;
skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, 0);
if (skb == NULL)
return -ENOMEM;
skb_queue_tail(&local->tx_queue, skb);
return 0;
}
int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
{
struct sk_buff *skb;
struct nfc_dev *dev;
u16 size = 1; /* Reason code */
pr_debug("Sending DM reason 0x%x\n", reason);
if (local == NULL)
return -ENODEV;
dev = local->dev;
if (dev == NULL)
return -ENODEV;
size += LLCP_HEADER_SIZE;
size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
skb = alloc_skb(size, GFP_KERNEL);
if (skb == NULL)
return -ENOMEM;
skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
skb = llcp_add_header(skb, ssap, dsap, LLCP_PDU_DM);
memcpy(skb_put(skb, 1), &reason, 1);
skb_queue_head(&local->tx_queue, skb);
return 0;
}
int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock)
{
struct sk_buff *skb;
struct nfc_llcp_local *local;
pr_debug("Send DISC\n");
local = sock->local;
if (local == NULL)
return -ENODEV;
skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0);
if (skb == NULL)
return -ENOMEM;
skb_queue_head(&local->tx_queue, skb);
return 0;
}