path: root/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 u16 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) & 0x7ff;
}

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;
}

struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdres_tlv(u8 tid, u8 sap)
{
	struct nfc_llcp_sdp_tlv *sdres;
	u8 value[2];

	sdres = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
	if (sdres == NULL)
		return NULL;

	value[0] = tid;
	value[1] = sap;

	sdres->tlv = nfc_llcp_build_tlv(LLCP_TLV_SDRES, value, 2,
					&sdres->tlv_len);
	if (sdres->tlv == NULL) {
		kfree(sdres);
		return NULL;
	}

	sdres->tid = tid;
	sdres->sap = sap;

	INIT_HLIST_NODE(&sdres->node);

	return sdres;
}

struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdreq_tlv(u8 tid, char *uri,
						  size_t uri_len)
{
	struct nfc_llcp_sdp_tlv *sdreq;

	pr_debug("uri: %s, len: %zu\n", uri, uri_len);

	sdreq = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
	if (sdreq == NULL)
		return NULL;

	sdreq->tlv_len = uri_len + 3;

	if (uri[uri_len - 1] == 0)
		sdreq->tlv_len--;

	sdreq->tlv = kzalloc(sdreq->tlv_len + 1, GFP_KERNEL);
	if (sdreq->tlv == NULL) {
		kfree(sdreq);
		return NULL;
	}

	sdreq->tlv[0] = LLCP_TLV_SDREQ;
	sdreq->tlv[1] = sdreq->tlv_len - 2;
	sdreq->tlv[2] = tid;

	sdreq->tid = tid;
	sdreq->uri = sdreq->tlv + 3;
	memcpy(sdreq->uri, uri, uri_len);

	sdreq->time = jiffies;

	INIT_HLIST_NODE(&sdreq->node);

	return sdreq;
}

void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp)
{
	kfree(sdp->tlv);
	kfree(sdp);
}

void nfc_llcp_free_sdp_tlv_list(struct hlist_head *head)
{
	struct nfc_llcp_sdp_tlv *sdp;
	struct hlist_node *n;

	hlist_for_each_entry_safe(sdp, n, head, node) {
		hlist_del(&sdp->node);

		nfc_llcp_free_sdp_tlv(sdp);
	}
}

int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
			  u8 <