[deliverable/linux.git] / net / nfc / llcp / commands.c

/*
 * 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 if (length == 0)
		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_gb_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;
		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\n",
		 local->remote_version, local->remote_miu,
		 local->remote_lto, local->remote_opt,
		 local->remote_wks);

	return 0;
}

int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
				  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 (sock == NULL)
		return -ENOTCONN;

	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_RW:
			sock->rw = llcp_tlv_rw(tlv);
			break;
		case LLCP_TLV_SN:
			break;
		default:
			pr_err("Invalid gt tlv value 0x%x\n", type);
			break;
		}

		offset += length + 2;
		tlv += length + 2;
	}

	pr_debug("sock %p rw %d\n", sock, sock->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->dsap, sock->ssap, 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;
	u8 *miux_tlv = NULL, miux_tlv_length;
	u8 *rw_tlv = NULL, rw_tlv_length, rw;
	__be16 miux;
	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;
	}

	miux = cpu_to_be16(LLCP_MAX_MIUX);
	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
				      &miux_tlv_length);
	size += miux_tlv_length;

	rw = LLCP_MAX_RW;
	rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
	size += rw_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 = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
	skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);

	skb_queue_tail(&local->tx_queue, skb);

	return 0;

error_tlv:
	pr_err("error %d\n", err);

	kfree(service_name_tlv);
	kfree(miux_tlv);
	kfree(rw_tlv);

	return err;
}

int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
{
	struct nfc_llcp_local *local;
	struct sk_buff *skb;
	u8 *miux_tlv = NULL, miux_tlv_length;
	u8 *rw_tlv = NULL, rw_tlv_length, rw;
	__be16 miux;
	int err;
	u16 size = 0;

	pr_debug("Sending CC\n");

	local = sock->local;
	if (local == NULL)
		return -ENODEV;

	miux = cpu_to_be16(LLCP_MAX_MIUX);
	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
				      &miux_tlv_length);
	size += miux_tlv_length;

	rw = LLCP_MAX_RW;
	rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
	size += rw_tlv_length;

	skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);
	if (skb == NULL) {
		err = -ENOMEM;
		goto error_tlv;
	}

	skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
	skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);

	skb_queue_tail(&local->tx_queue, skb);

	return 0;

error_tlv:
	pr_err("error %d\n", err);

	kfree(miux_tlv);
	kfree(rw_tlv);

	return err;
}

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, dsap, ssap, 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;
}

int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,
			  struct msghdr *msg, size_t len)
{
	struct sk_buff *pdu;
	struct sock *sk = &sock->sk;
	struct nfc_llcp_local *local;
	size_t frag_len = 0, remaining_len;
	u8 *msg_data, *msg_ptr;

	pr_debug("Send I frame len %zd\n", len);

	local = sock->local;
	if (local == NULL)
		return -ENODEV;

	msg_data = kzalloc(len, GFP_KERNEL);
	if (msg_data == NULL)
		return -ENOMEM;

	if (memcpy_fromiovec(msg_data, msg->msg_iov, len)) {
		kfree(msg_data);
		return -EFAULT;
	}

	remaining_len = len;
	msg_ptr = msg_data;

	while (remaining_len > 0) {

		frag_len = min_t(size_t, local->remote_miu, remaining_len);

		pr_debug("Fragment %zd bytes remaining %zd",
			 frag_len, remaining_len);

		pdu = llcp_allocate_pdu(sock, LLCP_PDU_I,
					frag_len + LLCP_SEQUENCE_SIZE);
		if (pdu == NULL)
			return -ENOMEM;

		skb_put(pdu, LLCP_SEQUENCE_SIZE);

		memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len);

		skb_queue_tail(&sock->tx_queue, pdu);

		lock_sock(sk);

		nfc_llcp_queue_i_frames(sock);

		release_sock(sk);

		remaining_len -= frag_len;
		msg_ptr += frag_len;
	}

	kfree(msg_data);

	return len;
}

int nfc_llcp_send_rr(struct nfc_llcp_sock *sock)
{
	struct sk_buff *skb;
	struct nfc_llcp_local *local;

	pr_debug("Send rr nr %d\n", sock->recv_n);

	local = sock->local;
	if (local == NULL)
		return -ENODEV;

	skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE);
	if (skb == NULL)
		return -ENOMEM;

	skb_put(skb, LLCP_SEQUENCE_SIZE);

	skb->data[2] = sock->recv_n;

	skb_queue_head(&local->tx_queue, skb);

	return 0;
}
Commit	Line	Data
d646960f SO	1	/*
	2	* Copyright (C) 2011 Intel Corporation. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the
	16	* Free Software Foundation, Inc.,
	17	* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	18	*/
	19
	20	#define pr_fmt(fmt) "llcp: %s: " fmt, __func__
	21
	22	#include <linux/init.h>
	23	#include <linux/kernel.h>
	24	#include <linux/module.h>
	25	#include <linux/nfc.h>
	26
	27	#include <net/nfc/nfc.h>
	28
	29	#include "../nfc.h"
	30	#include "llcp.h"
	31
	32	static u8 llcp_tlv_length[LLCP_TLV_MAX] = {
	33	0,
	34	1, /* VERSION */
	35	2, /* MIUX */
	36	2, /* WKS */
	37	1, /* LTO */
	38	1, /* RW */
	39	0, /* SN */
	40	1, /* OPT */
	41	0, /* SDREQ */
	42	2, /* SDRES */
	43
	44	};
	45
	46	static u8 llcp_tlv8(u8 *tlv, u8 type)
	47	{
	48	if (tlv[0] != type \|\| tlv[1] != llcp_tlv_length[tlv[0]])
	49	return 0;
	50
	51	return tlv[2];
	52	}
	53
	54	static u8 llcp_tlv16(u8 *tlv, u8 type)
	55	{
	56	if (tlv[0] != type \|\| tlv[1] != llcp_tlv_length[tlv[0]])
	57	return 0;
	58
	59	return be16_to_cpu(((__be16 )(tlv + 2)));
	60	}
	61
	62
	63	static u8 llcp_tlv_version(u8 *tlv)
	64	{
65	return llcp_tlv8(tlv, LLCP_TLV_VERSION);
66	}
67
68	static u16 llcp_tlv_miux(u8 *tlv)
69	{
70	return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7f;
71	}
72
73	static u16 llcp_tlv_wks(u8 *tlv)
74	{
75	return llcp_tlv16(tlv, LLCP_TLV_WKS);
76	}
77
78	static u16 llcp_tlv_lto(u8 *tlv)
79	{
80	return llcp_tlv8(tlv, LLCP_TLV_LTO);
81	}
82
83	static u8 llcp_tlv_opt(u8 *tlv)
84	{
85	return llcp_tlv8(tlv, LLCP_TLV_OPT);
86	}
87
88	static u8 llcp_tlv_rw(u8 *tlv)
89	{
90	return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf;
91	}
92
93	u8 nfc_llcp_build_tlv(u8 type, u8 value, u8 value_length, u8 *tlv_length)
94	{
95	u8 *tlv, length;
96
97	pr_debug("type %d\n", type);
98
99	if (type >= LLCP_TLV_MAX)
100	return NULL;
101
102	length = llcp_tlv_length[type];
103	if (length == 0 && value_length == 0)
104	return NULL;
324b0af6	105	else if (length == 0)
d646960f SO	106	length = value_length;
	107
	108	*tlv_length = 2 + length;
	109	tlv = kzalloc(2 + length, GFP_KERNEL);
	110	if (tlv == NULL)
	111	return tlv;
	112
	113	tlv[0] = type;
	114	tlv[1] = length;
	115	memcpy(tlv + 2, value, length);
	116
	117	return tlv;
	118	}
	119
7a06e586 SO	120	int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
7a06e586 SO	121	u8 *tlv_array, u16 tlv_array_len)
d646960f SO	122	{
	123	u8 *tlv = tlv_array, type, length, offset = 0;
	124
	125	pr_debug("TLV array length %d\n", tlv_array_len);
	126
	127	if (local == NULL)
	128	return -ENODEV;
	129
	130	while (offset < tlv_array_len) {
	131	type = tlv[0];
	132	length = tlv[1];
	133
	134	pr_debug("type 0x%x length %d\n", type, length);
	135
	136	switch (type) {
	137	case LLCP_TLV_VERSION:
	138	local->remote_version = llcp_tlv_version(tlv);
	139	break;
	140	case LLCP_TLV_MIUX:
	141	local->remote_miu = llcp_tlv_miux(tlv) + 128;
	142	break;
	143	case LLCP_TLV_WKS:
	144	local->remote_wks = llcp_tlv_wks(tlv);
	145	break;
	146	case LLCP_TLV_LTO:
	147	local->remote_lto = llcp_tlv_lto(tlv) * 10;
	148	break;
	149	case LLCP_TLV_OPT:
	150	local->remote_opt = llcp_tlv_opt(tlv);
	151	break;
7a06e586 SO	152	default:
	153	pr_err("Invalid gt tlv value 0x%x\n", type);
	154	break;
	155	}
	156
	157	offset += length + 2;
	158	tlv += length + 2;
	159	}
	160
	161	pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x\n",
	162	local->remote_version, local->remote_miu,
	163	local->remote_lto, local->remote_opt,
	164	local->remote_wks);
	165
	166	return 0;
	167	}
	168
	169	int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
	170	u8 *tlv_array, u16 tlv_array_len)
	171	{
	172	u8 *tlv = tlv_array, type, length, offset = 0;
	173
	174	pr_debug("TLV array length %d\n", tlv_array_len);
	175
	176	if (sock == NULL)
	177	return -ENOTCONN;
	178
	179	while (offset < tlv_array_len) {
	180	type = tlv[0];
	181	length = tlv[1];
	182
	183	pr_debug("type 0x%x length %d\n", type, length);
	184
	185	switch (type) {
d646960f	186	case LLCP_TLV_RW:
7a06e586	187	sock->rw = llcp_tlv_rw(tlv);
d646960f	188	break;
9dda50f4 SO	189	case LLCP_TLV_SN:
9dda50f4 SO	190	break;
d646960f SO	191	default:
	192	pr_err("Invalid gt tlv value 0x%x\n", type);
	193	break;
	194	}
	195
	196	offset += length + 2;
	197	tlv += length + 2;
	198	}
	199
7a06e586	200	pr_debug("sock %p rw %d\n", sock, sock->rw);
d646960f SO	201
	202	return 0;
	203	}
	204
	205	static struct sk_buff llcp_add_header(struct sk_buff pdu,
427a2eb1	206	u8 dsap, u8 ssap, u8 ptype)
d646960f SO	207	{
	208	u8 header[2];
	209
	210	pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
	211
	212	header[0] = (u8)((dsap << 2) \| (ptype >> 2));
	213	header[1] = (u8)((ptype << 6) \| ssap);
	214
	215	pr_debug("header 0x%x 0x%x\n", header[0], header[1]);
	216
	217	memcpy(skb_put(pdu, LLCP_HEADER_SIZE), header, LLCP_HEADER_SIZE);
	218
	219	return pdu;
	220	}
	221
427a2eb1 SO	222	static struct sk_buff llcp_add_tlv(struct sk_buff pdu, u8 *tlv,
427a2eb1 SO	223	u8 tlv_length)
d646960f SO	224	{
	225	/* XXX Add an skb length check */
	226
	227	if (tlv == NULL)
	228	return NULL;
	229
	230	memcpy(skb_put(pdu, tlv_length), tlv, tlv_length);
	231
	232	return pdu;
	233	}
	234
	235	static struct sk_buff llcp_allocate_pdu(struct nfc_llcp_sock sock,
427a2eb1	236	u8 cmd, u16 size)
d646960f SO	237	{
	238	struct sk_buff *skb;
	239	int err;
	240
	241	if (sock->ssap == 0)
	242	return NULL;
	243
	244	skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
427a2eb1	245	size + LLCP_HEADER_SIZE, &err);
d646960f SO	246	if (skb == NULL) {
	247	pr_err("Could not allocate PDU\n");
	248	return NULL;
	249	}
	250
	251	skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd);
	252
	253	return skb;
	254	}
	255
	256	int nfc_llcp_disconnect(struct nfc_llcp_sock *sock)
	257	{
	258	struct sk_buff *skb;
	259	struct nfc_dev *dev;
	260	struct nfc_llcp_local *local;
	261	u16 size = 0;
	262
	263	pr_debug("Sending DISC\n");
	264
	265	local = sock->local;
	266	if (local == NULL)
	267	return -ENODEV;
	268
	269	dev = sock->dev;
	270	if (dev == NULL)
	271	return -ENODEV;
	272
	273	size += LLCP_HEADER_SIZE;
	274	size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
	275
	276	skb = alloc_skb(size, GFP_ATOMIC);
	277	if (skb == NULL)
	278	return -ENOMEM;
	279
	280	skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
	281
ffc29315	282	skb = llcp_add_header(skb, sock->dsap, sock->ssap, LLCP_PDU_DISC);
d646960f SO	283
	284	skb_queue_tail(&local->tx_queue, skb);
	285
	286	return 0;
	287	}
	288
	289	int nfc_llcp_send_symm(struct nfc_dev *dev)
	290	{
	291	struct sk_buff *skb;
	292	struct nfc_llcp_local *local;
	293	u16 size = 0;
	294
	295	pr_debug("Sending SYMM\n");
	296
	297	local = nfc_llcp_find_local(dev);
	298	if (local == NULL)
	299	return -ENODEV;
	300
	301	size += LLCP_HEADER_SIZE;
	302	size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
	303
	304	skb = alloc_skb(size, GFP_KERNEL);
	305	if (skb == NULL)
	306	return -ENOMEM;
	307
	308	skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
	309
	310	skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM);
	311
	312	return nfc_data_exchange(dev, local->target_idx, skb,
427a2eb1	313	nfc_llcp_recv, local);
d646960f SO	314	}
	315
	316	int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
	317	{
	318	struct nfc_llcp_local *local;
	319	struct sk_buff *skb;
	320	u8 *service_name_tlv = NULL, service_name_tlv_length;
eda21f16 SO	321	u8 *miux_tlv = NULL, miux_tlv_length;
	322	u8 *rw_tlv = NULL, rw_tlv_length, rw;
	323	__be16 miux;
d646960f SO	324	int err;
	325	u16 size = 0;
	326
	327	pr_debug("Sending CONNECT\n");
	328
	329	local = sock->local;
	330	if (local == NULL)
	331	return -ENODEV;
	332
	333	if (sock->service_name != NULL) {
	334	service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN,
427a2eb1 SO	335	sock->service_name,
	336	sock->service_name_len,
	337	&service_name_tlv_length);
d646960f SO	338	size += service_name_tlv_length;
	339	}
	340
eda21f16	341	miux = cpu_to_be16(LLCP_MAX_MIUX);
427a2eb1 SO	342	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
427a2eb1 SO	343	&miux_tlv_length);
eda21f16 SO	344	size += miux_tlv_length;
	345
	346	rw = LLCP_MAX_RW;
	347	rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
	348	size += rw_tlv_length;
	349
d646960f SO	350	pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len);
	351
	352	skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size);
	353	if (skb == NULL) {
	354	err = -ENOMEM;
	355	goto error_tlv;
	356	}
	357
	358	if (service_name_tlv != NULL)
	359	skb = llcp_add_tlv(skb, service_name_tlv,
427a2eb1	360	service_name_tlv_length);
d646960f	361
eda21f16 SO	362	skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
	363	skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
	364
d646960f SO	365	skb_queue_tail(&local->tx_queue, skb);
	366
	367	return 0;
	368
	369	error_tlv:
	370	pr_err("error %d\n", err);
	371
	372	kfree(service_name_tlv);
eda21f16 SO	373	kfree(miux_tlv);
eda21f16 SO	374	kfree(rw_tlv);
d646960f SO	375
	376	return err;
	377	}
	378
	379	int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
	380	{
	381	struct nfc_llcp_local *local;
	382	struct sk_buff *skb;
eda21f16 SO	383	u8 *miux_tlv = NULL, miux_tlv_length;
	384	u8 *rw_tlv = NULL, rw_tlv_length, rw;
	385	__be16 miux;
	386	int err;
	387	u16 size = 0;
d646960f SO	388
	389	pr_debug("Sending CC\n");
	390
	391	local = sock->local;
	392	if (local == NULL)
	393	return -ENODEV;
	394
eda21f16	395	miux = cpu_to_be16(LLCP_MAX_MIUX);
427a2eb1 SO	396	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
427a2eb1 SO	397	&miux_tlv_length);
eda21f16 SO	398	size += miux_tlv_length;
	399
	400	rw = LLCP_MAX_RW;
	401	rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
	402	size += rw_tlv_length;
	403
	404	skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);
	405	if (skb == NULL) {
	406	err = -ENOMEM;
	407	goto error_tlv;
	408	}
	409
	410	skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
	411	skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
d646960f SO	412
	413	skb_queue_tail(&local->tx_queue, skb);
	414
	415	return 0;
eda21f16 SO	416
	417	error_tlv:
	418	pr_err("error %d\n", err);
	419
	420	kfree(miux_tlv);
	421	kfree(rw_tlv);
	422
	423	return err;
d646960f SO	424	}
	425
	426	int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
	427	{
	428	struct sk_buff *skb;
	429	struct nfc_dev *dev;
	430	u16 size = 1; /* Reason code */
	431
	432	pr_debug("Sending DM reason 0x%x\n", reason);
	433
	434	if (local == NULL)
	435	return -ENODEV;
	436
	437	dev = local->dev;
	438	if (dev == NULL)
	439	return -ENODEV;
	440
	441	size += LLCP_HEADER_SIZE;
	442	size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
	443
	444	skb = alloc_skb(size, GFP_KERNEL);
	445	if (skb == NULL)
	446	return -ENOMEM;
	447
	448	skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
	449
ffc29315	450	skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM);
d646960f SO	451
	452	memcpy(skb_put(skb, 1), &reason, 1);
	453
	454	skb_queue_head(&local->tx_queue, skb);
	455
	456	return 0;
	457	}
	458
	459	int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock)
	460	{
	461	struct sk_buff *skb;
	462	struct nfc_llcp_local *local;
	463
	464	pr_debug("Send DISC\n");
	465
	466	local = sock->local;
	467	if (local == NULL)
	468	return -ENODEV;
	469
	470	skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0);
	471	if (skb == NULL)
	472	return -ENOMEM;
	473
	474	skb_queue_head(&local->tx_queue, skb);
	475
	476	return 0;
	477	}
53a0ac2e SO	478
53a0ac2e SO	479	int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,
427a2eb1	480	struct msghdr *msg, size_t len)
53a0ac2e SO	481	{
53a0ac2e SO	482	struct sk_buff *pdu;
e65b0f46 SO	483	struct sock *sk = &sock->sk;
	484	struct nfc_llcp_local *local;
	485	size_t frag_len = 0, remaining_len;
	486	u8 msg_data, msg_ptr;
53a0ac2e	487
e65b0f46	488	pr_debug("Send I frame len %zd\n", len);
53a0ac2e	489
e65b0f46 SO	490	local = sock->local;
	491	if (local == NULL)
	492	return -ENODEV;
53a0ac2e	493
e65b0f46 SO	494	msg_data = kzalloc(len, GFP_KERNEL);
	495	if (msg_data == NULL)
	496	return -ENOMEM;
53a0ac2e	497
e65b0f46	498	if (memcpy_fromiovec(msg_data, msg->msg_iov, len)) {
427a2eb1 SO	499	kfree(msg_data);
427a2eb1 SO	500	return -EFAULT;
53a0ac2e SO	501	}
53a0ac2e SO	502
e65b0f46 SO	503	remaining_len = len;
	504	msg_ptr = msg_data;
	505
	506	while (remaining_len > 0) {
	507
b4838d12	508	frag_len = min_t(size_t, local->remote_miu, remaining_len);
53a0ac2e	509
e65b0f46 SO	510	pr_debug("Fragment %zd bytes remaining %zd",
e65b0f46 SO	511	frag_len, remaining_len);
53a0ac2e	512
e65b0f46 SO	513	pdu = llcp_allocate_pdu(sock, LLCP_PDU_I,
	514	frag_len + LLCP_SEQUENCE_SIZE);
	515	if (pdu == NULL)
	516	return -ENOMEM;
	517
	518	skb_put(pdu, LLCP_SEQUENCE_SIZE);
	519
	520	memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len);
	521
bdbc59b3	522	skb_queue_tail(&sock->tx_queue, pdu);
e65b0f46 SO	523
	524	lock_sock(sk);
	525
	526	nfc_llcp_queue_i_frames(sock);
	527
	528	release_sock(sk);
	529
	530	remaining_len -= frag_len;
b4838d12	531	msg_ptr += frag_len;
e65b0f46	532	}
53a0ac2e	533
e65b0f46	534	kfree(msg_data);
53a0ac2e	535
43472fff	536	return len;
53a0ac2e	537	}
d094afa1 SO	538
	539	int nfc_llcp_send_rr(struct nfc_llcp_sock *sock)
	540	{
	541	struct sk_buff *skb;
	542	struct nfc_llcp_local *local;
	543
	544	pr_debug("Send rr nr %d\n", sock->recv_n);
	545
	546	local = sock->local;
	547	if (local == NULL)
	548	return -ENODEV;
	549
	550	skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE);
	551	if (skb == NULL)
	552	return -ENOMEM;
	553
	554	skb_put(skb, LLCP_SEQUENCE_SIZE);
	555
279cf174	556	skb->data[2] = sock->recv_n;
d094afa1 SO	557
	558	skb_queue_head(&local->tx_queue, skb);
	559
	560	return 0;
	561	}