NFC: Initial LLCP support

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

10 files changed, 2335 insertions, 3 deletions

diff --git a/include/linux/nfc.h b/include/linux/nfc.h
index 34d8303111f..89fee4ab190 100644
--- a/include/linux/nfc.h
+++ b/include/linux/nfc.h
@@ -139,9 +139,22 @@ struct sockaddr_nfc {
 	__u32 nfc_protocol;
 };
 
+#define NFC_LLCP_MAX_SERVICE_NAME 63
+struct sockaddr_nfc_llcp {
+	sa_family_t sa_family;
+	__u32 dev_idx;
+	__u32 target_idx;
+	__u32 nfc_protocol;
+	__u8 dsap; /* Destination SAP, if known */
+	__u8 ssap; /* Source SAP to be bound to */
+	char service_name[NFC_LLCP_MAX_SERVICE_NAME]; /* Service name URI */;
+	size_t service_name_len;
+};
+
 /* NFC socket protocols */
 #define NFC_SOCKPROTO_RAW	0
-#define NFC_SOCKPROTO_MAX	1
+#define NFC_SOCKPROTO_LLCP	1
+#define NFC_SOCKPROTO_MAX	2
 
 #define NFC_HEADER_SIZE 1
 
diff --git a/net/nfc/Kconfig b/net/nfc/Kconfig
index 58cddadf8e8..44c865b86d6 100644
--- a/net/nfc/Kconfig
+++ b/net/nfc/Kconfig
@@ -14,5 +14,6 @@ menuconfig NFC
 	  be called nfc.
 
 source "net/nfc/nci/Kconfig"
+source "net/nfc/llcp/Kconfig"
 
 source "drivers/nfc/Kconfig"
diff --git a/net/nfc/Makefile b/net/nfc/Makefile
index fbb550f2377..7b4a6dcfa56 100644
--- a/net/nfc/Makefile
+++ b/net/nfc/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_NFC) += nfc.o
 obj-$(CONFIG_NFC_NCI) += nci/
 
 nfc-objs := core.o netlink.o af_nfc.o rawsock.o
+nfc-$(CONFIG_NFC_LLCP)	+= llcp/llcp.o llcp/commands.o llcp/sock.o
diff --git a/net/nfc/core.c b/net/nfc/core.c
index 3a45f21b3b9..3ddf6e698df 100644
--- a/net/nfc/core.c
+++ b/net/nfc/core.c
@@ -240,6 +240,7 @@ int nfc_dep_link_down(struct nfc_dev *dev)
 	rc = dev->ops->dep_link_down(dev);
 	if (!rc) {
 		dev->dep_link_up = false;
+		nfc_llcp_mac_is_down(dev);
 		nfc_genl_dep_link_down_event(dev);
 	}
 
@@ -254,6 +255,8 @@ int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx,
 	dev->dep_link_up = true;
 	dev->dep_rf_mode = rf_mode;
 
+	nfc_llcp_mac_is_up(dev, target_idx, comm_mode, rf_mode);
+
 	return nfc_genl_dep_link_up_event(dev, target_idx, comm_mode, rf_mode);
 }
 EXPORT_SYMBOL(nfc_dep_link_is_up);
@@ -360,13 +363,13 @@ int nfc_set_remote_general_bytes(struct nfc_dev *dev, u8 *gb, u8 gb_len)
 	if (gb_len > NFC_MAX_GT_LEN)
 		return -EINVAL;
 
-	return 0;
+	return nfc_llcp_set_remote_gb(dev, gb, gb_len);
 }
 EXPORT_SYMBOL(nfc_set_remote_general_bytes);
 
 u8 *nfc_get_local_general_bytes(struct nfc_dev *dev, u8 *gt_len)
 {
-	return NULL;
+	return nfc_llcp_general_bytes(dev, gt_len);
 }
 EXPORT_SYMBOL(nfc_get_local_general_bytes);
 
@@ -560,6 +563,10 @@ int nfc_register_device(struct nfc_dev *dev)
 	if (rc < 0)
 		return rc;
 
+	rc = nfc_llcp_register_device(dev);
+	if (rc)
+		pr_err("Could not register llcp device\n");
+
 	rc = nfc_genl_device_added(dev);
 	if (rc)
 		pr_debug("The userspace won't be notified that the device %s was added\n",
@@ -591,6 +598,8 @@ void nfc_unregister_device(struct nfc_dev *dev)
 
 	mutex_unlock(&nfc_devlist_mutex);
 
+	nfc_llcp_unregister_device(dev);
+
 	rc = nfc_genl_device_removed(dev);
 	if (rc)
 		pr_debug("The userspace won't be notified that the device %s was removed\n",
@@ -620,6 +629,10 @@ static int __init nfc_init(void)
 	if (rc)
 		goto err_rawsock;
 
+	rc = nfc_llcp_init();
+	if (rc)
+		goto err_llcp_sock;
+
 	rc = af_nfc_init();
 	if (rc)
 		goto err_af_nfc;
@@ -627,6 +640,8 @@ static int __init nfc_init(void)
 	return 0;
 
 err_af_nfc:
+	nfc_llcp_exit();
+err_llcp_sock:
 	rawsock_exit();
 err_rawsock:
 	nfc_genl_exit();
@@ -638,6 +653,7 @@ err_genl:
 static void __exit nfc_exit(void)
 {
 	af_nfc_exit();
+	nfc_llcp_exit();
 	rawsock_exit();
 	nfc_genl_exit();
 	class_unregister(&nfc_class);
diff --git a/net/nfc/llcp/Kconfig b/net/nfc/llcp/Kconfig
new file mode 100644
index 00000000000..fbf5e815090
--- /dev/null
+++ b/net/nfc/llcp/Kconfig
@@ -0,0 +1,7 @@
+config NFC_LLCP
+       depends on NFC && EXPERIMENTAL
+       bool "NFC LLCP support (EXPERIMENTAL)"
+       default n
+       help
+	 Say Y here if you want to build support for a kernel NFC LLCP
+	 implementation.
\ No newline at end of file
diff --git a/net/nfc/llcp/commands.c b/net/nfc/llcp/commands.c
new file mode 100644
index 00000000000..151f2ef429c
--- /dev/null
+++ b/net/nfc/llcp/commands.c
@@ -0,0 +1,399 @@
+/*
+ * 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;
+}
diff --git a/net/nfc/llcp/llcp.c b/net/nfc/llcp/llcp.c
new file mode 100644
index 00000000000..67756b23eac
--- /dev/null
+++ b/net/nfc/llcp/llcp.c
@@ -0,0 +1,973 @@
+/*
+ * 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/list.h>
+#include <linux/nfc.h>
+
+#include "../nfc.h"
+#include "llcp.h"
+
+static u8 llcp_magic[3] = {0x46, 0x66, 0x6d};
+
+static struct list_head llcp_devices;
+
+static void nfc_llcp_socket_release(struct nfc_llcp_local *local)
+{
+	struct nfc_llcp_sock *parent, *s, *n;
+	struct sock *sk, *parent_sk;
+	int i;
+
+
+	mutex_lock(&local->socket_lock);
+
+	for (i = 0; i < LLCP_MAX_SAP; i++) {
+		parent = local->sockets[i];
+		if (parent == NULL)
+			continue;
+
+		/* Release all child sockets */
+		list_for_each_entry_safe(s, n, &parent->list, list) {
+			list_del(&s->list);
+			sk = &s->sk;
+
+			lock_sock(sk);
+
+			if (sk->sk_state == LLCP_CONNECTED)
+				nfc_put_device(s->dev);
+
+			sk->sk_state = LLCP_CLOSED;
+			sock_set_flag(sk, SOCK_DEAD);
+
+			release_sock(sk);
+		}
+
+		parent_sk = &parent->sk;
+
+		lock_sock(parent_sk);
+
+		if (parent_sk->sk_state == LLCP_LISTEN) {
+			struct nfc_llcp_sock *lsk, *n;
+			struct sock *accept_sk;
+
+			list_for_each_entry_safe(lsk, n, &parent->accept_queue,
+								accept_queue) {
+				accept_sk = &lsk->sk;
+				lock_sock(accept_sk);
+
+				nfc_llcp_accept_unlink(accept_sk);
+
+				accept_sk->sk_state = LLCP_CLOSED;
+				sock_set_flag(accept_sk, SOCK_DEAD);
+
+				release_sock(accept_sk);
+
+				sock_orphan(accept_sk);
+			}
+		}
+
+		if (parent_sk->sk_state == LLCP_CONNECTED)
+			nfc_put_device(parent->dev);
+
+		parent_sk->sk_state = LLCP_CLOSED;
+		sock_set_flag(parent_sk, SOCK_DEAD);
+
+		release_sock(parent_sk);
+	}
+
+	mutex_unlock(&local->socket_lock);
+}
+
+static void nfc_llcp_timeout_work(struct work_struct *work)
+{
+	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
+							timeout_work);
+
+	nfc_dep_link_down(local->dev);
+}
+
+static void nfc_llcp_symm_timer(unsigned long data)
+{
+	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
+
+	pr_err("SYMM timeout\n");
+
+	queue_work(local->timeout_wq, &local->timeout_work);
+}
+
+struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
+{
+	struct nfc_llcp_local *local, *n;
+
+	list_for_each_entry_safe(local, n, &llcp_devices, list)
+		if (local->dev == dev)
+			return local;
+
+	pr_debug("No device found\n");
+
+	return NULL;
+}
+
+static char *wks[] = {
+	NULL,
+	NULL, /* SDP */
+	"urn:nfc:sn:ip",
+	"urn:nfc:sn:obex",
+	"urn:nfc:sn:snep",
+};
+
+static int nfc_llcp_wks_sap(char *service_name, size_t service_name_len)
+{
+	int sap, num_wks;
+
+	pr_debug("%s\n", service_name);
+
+	if (service_name == NULL)
+		return -EINVAL;
+
+	num_wks = ARRAY_SIZE(wks);
+
+	for (sap = 0 ; sap < num_wks; sap++) {
+		if (wks[sap] == NULL)
+			continue;
+
+		if (strncmp(wks[sap], service_name, service_name_len) == 0)
+			return sap;
+	}
+
+	return -EINVAL;
+}
+
+u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
+				struct nfc_llcp_sock *sock)
+{
+	mutex_lock(&local->sdp_lock);
+
+	if (sock->service_name != NULL && sock->service_name_len > 0) {
+		int ssap = nfc_llcp_wks_sap(sock->service_name,
+						sock->service_name_len);
+
+		if (ssap > 0) {
+			pr_debug("WKS %d\n", ssap);
+
+			/* This is a WKS, let's check if it's free */
+			if (local->local_wks & BIT(ssap)) {
+				mutex_unlock(&local->sdp_lock);
+
+				return LLCP_SAP_MAX;
+			}
+
+			set_bit(BIT(ssap), &local->local_wks);
+			mutex_unlock(&local->sdp_lock);
+
+			return ssap;
+		}
+
+		/*
+		 * This is not a well known service,
+		 * we should try to find a local SDP free spot
+		 */
+		ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
+		if (ssap == LLCP_SDP_NUM_SAP) {
+			mutex_unlock(&local->sdp_lock);
+
+			return LLCP_SAP_MAX;
+		}
+
+		pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
+
+		set_bit(BIT(ssap), &local->local_sdp);
+		mutex_unlock(&local->sdp_lock);
+
+		return LLCP_WKS_NUM_SAP + ssap;
+
+	} else if (sock->ssap != 0) {
+		if (sock->ssap < LLCP_WKS_NUM_SAP) {
+			if (!(local->local_wks & BIT(sock->ssap))) {
+				set_bit(BIT(sock->ssap), &local->local_wks);
+				mutex_unlock(&local->sdp_lock);
+
+				return sock->ssap;
+			}
+
+		} else if (sock->ssap < LLCP_SDP_NUM_SAP) {
+			if (!(local->local_sdp &
+				BIT(sock->ssap - LLCP_WKS_NUM_SAP))) {
+				set_bit(BIT(sock->ssap - LLCP_WKS_NUM_SAP),
+							&local->local_sdp);
+				mutex_unlock(&local->sdp_lock);
+
+				return sock->ssap;
+			}
+		}
+	}
+
+	mutex_unlock(&local->sdp_lock);
+
+	return LLCP_SAP_MAX;
+}
+
+u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
+{
+	u8 local_ssap;
+
+	mutex_lock(&local->sdp_lock);
+
+	local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
+	if (local_ssap == LLCP_LOCAL_NUM_SAP) {
+		mutex_unlock(&local->sdp_lock);
+		return LLCP_SAP_MAX;
+	}
+
+	set_bit(BIT(local_ssap), &local->local_sap);
+
+	mutex_unlock(&local->sdp_lock);
+
+	return local_ssap + LLCP_LOCAL_SAP_OFFSET;
+}
+
+void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
+{
+	u8 local_ssap;
+	unsigned long *sdp;
+
+	if (ssap < LLCP_WKS_NUM_SAP) {
+		local_ssap = ssap;
+		sdp = &local->local_wks;
+	} else if (ssap < LLCP_LOCAL_NUM_SAP) {
+		local_ssap = ssap - LLCP_WKS_NUM_SAP;
+		sdp = &local->local_sdp;
+	} else if (ssap < LLCP_MAX_SAP) {
+		local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
+		sdp = &local->local_sap;
+	} else {
+		return;
+	}
+
+	mutex_lock(&local->sdp_lock);
+
+	clear_bit(1 << local_ssap, sdp);
+
+	mutex_unlock(&local->sdp_lock);
+}
+
+u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, u8 *general_bytes_len)
+{
+	struct nfc_llcp_local *local;
+
+	local = nfc_llcp_find_local(dev);
+	if (local == NULL) {
+		*general_bytes_len = 0;
+		return NULL;
+	}
+
+	*general_bytes_len = local->gb_len;
+
+	return local->gb;
+}
+
+static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
+{
+	u8 *gb_cur, *version_tlv, version, version_length;
+	u8 *lto_tlv, lto, lto_length;
+	u8 *wks_tlv, wks_length;
+	u8 gb_len = 0;
+
+	version = LLCP_VERSION_11;
+	version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
+							1, &version_length);
+	gb_len += version_length;
+
+	/* 1500 ms */
+	lto = 150;
+	lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &lto, 1, &lto_length);
+	gb_len += lto_length;
+
+	pr_debug("Local wks 0x%lx\n", local->local_wks);
+	wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&local->local_wks, 2,
+								&wks_length);
+	gb_len += wks_length;
+
+	gb_len += ARRAY_SIZE(llcp_magic);
+
+	if (gb_len > NFC_MAX_GT_LEN) {
+		kfree(version_tlv);
+		return -EINVAL;
+	}
+
+	gb_cur = local->gb;
+
+	memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
+	gb_cur += ARRAY_SIZE(llcp_magic);
+
+	memcpy(gb_cur, version_tlv, version_length);
+	gb_cur += version_length;
+
+	memcpy(gb_cur, lto_tlv, lto_length);
+	gb_cur += lto_length;
+
+	memcpy(gb_cur, wks_tlv, wks_length);
+	gb_cur += wks_length;
+
+	kfree(version_tlv);
+	kfree(lto_tlv);
+
+	local->gb_len = gb_len;
+
+	return 0;
+}
+
+int nfc_llcp_set_remote_gb(struct nfc_dev *dev, u8 *gb, u8 gb_len)
+{
+	struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
+
+	if (local == NULL) {
+		pr_err("No LLCP device\n");
+		return -ENODEV;
+	}
+
+	memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
+	memcpy(local->remote_gb, gb, gb_len);
+	local->remote_gb_len = gb_len;
+
+	if (local->remote_gb == NULL ||
+			local->remote_gb_len == 0)
+		return -ENODEV;
+
+	if (memcmp(local->remote_gb, llcp_magic, 3)) {
+		pr_err("MAC does not support LLCP\n");
+		return -EINVAL;
+	}
+
+	return nfc_llcp_parse_tlv(local,
+			&local->remote_gb[3], local->remote_gb_len - 3);
+}
+
+static void nfc_llcp_tx_work(struct work_struct *work)
+{
+	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
+							tx_work);
+	struct sk_buff *skb;
+
+	skb = skb_dequeue(&local->tx_queue);
+	if (skb != NULL) {
+		pr_debug("Sending pending skb\n");
+		nfc_data_exchange(local->dev, local->target_idx,
+					skb, nfc_llcp_recv, local);
+	} else {
+		nfc_llcp_send_symm(local->dev);
+	}
+
+	mod_timer(&local->link_timer,
+			jiffies + msecs_to_jiffies(local->remote_lto));
+}
+
+static u8 nfc_llcp_dsap(struct sk_buff *pdu)
+{
+	return (pdu->data[0] & 0xfc) >> 2;
+}
+
+static u8 nfc_llcp_ptype(struct sk_buff *pdu)
+{
+	return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
+}
+
+static u8 nfc_llcp_ssap(struct sk_buff *pdu)
+{
+	return pdu->data[1] & 0x3f;
+}
+
+static u8 nfc_llcp_ns(struct sk_buff *pdu)
+{
+	return pdu->data[2] >> 4;
+}
+
+static u8 nfc_llcp_nr(struct sk_buff *pdu)
+{
+	return pdu->data[2] & 0xf;
+}
+
+static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
+{
+	pdu->data[2] = (sock->send_n << 4) | ((sock->recv_n - 1) % 16);
+	sock->send_n = (sock->send_n + 1) % 16;
+	sock->recv_ack_n = (sock->recv_n - 1) % 16;
+}
+
+static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
+						u8 ssap, u8 dsap)
+{
+	struct nfc_llcp_sock *sock, *llcp_sock, *n;
+
+	if (ssap == 0 && dsap == 0)
+		return NULL;
+
+	mutex_lock(&local->socket_lock);
+	sock = local->sockets[ssap];
+	if (sock == NULL) {
+		mutex_unlock(&local->socket_lock);
+		return NULL;
+	}
+
+	pr_debug("root dsap %d (%d)\n", sock->dsap, dsap);
+
+	if (sock->dsap == dsap) {
+		sock_hold(&sock->sk);
+		mutex_unlock(&local->socket_lock);
+		return sock;
+	}
+
+	list_for_each_entry_safe(llcp_sock, n, &sock->list, list) {
+		pr_debug("llcp_sock %p sk %p dsap %d\n", llcp_sock,
+				&llcp_sock->sk, llcp_sock->dsap);
+		if (llcp_sock->dsap == dsap) {
+			sock_hold(&llcp_sock->sk);
+			mutex_unlock(&local->socket_lock);
+			return llcp_sock;
+		}
+	}
+
+	pr_err("Could not find socket for %d %d\n", ssap, dsap);
+
+	mutex_unlock(&local->socket_lock);
+
+	return NULL;
+}
+
+static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
+{
+	sock_put(&sock->sk);
+}
+
+static u8 *nfc_llcp_connect_sn(struct sk_buff *skb, size_t *sn_len)
+{
+	u8 *tlv = &skb->data[2], type, length;
+	size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
+
+	while (offset < tlv_array_len) {
+		type = tlv[0];
+		length = tlv[1];
+
+		pr_debug("type 0x%x length %d\n", type, length);
+
+		if (type == LLCP_TLV_SN) {
+			*sn_len = length;
+			return &tlv[2];
+		}
+
+		offset += length + 2;
+		tlv += length + 2;
+	}
+
+	return NULL;
+}
+
+static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
+				struct sk_buff *skb)
+{
+	struct sock *new_sk, *parent;
+	struct nfc_llcp_sock *sock, *new_sock;
+	u8 dsap, ssap, bound_sap, reason;
+
+	dsap = nfc_llcp_dsap(skb);
+	ssap = nfc_llcp_ssap(skb);
+
+	pr_debug("%d %d\n", dsap, ssap);
+
+	nfc_llcp_parse_tlv(local, &skb->data[LLCP_HEADER_SIZE],
+				skb->len - LLCP_HEADER_SIZE);
+
+	if (dsap != LLCP_SAP_SDP) {
+		bound_sap = dsap;
+
+		mutex_lock(&local->socket_lock);
+		sock = local->sockets[dsap];
+		if (sock == NULL) {
+			mutex_unlock(&local->socket_lock);
+			reason = LLCP_DM_NOBOUND;
+			goto fail;
+		}
+
+		sock_hold(&sock->sk);
+		mutex_unlock(&local->socket_lock);
+
+		lock_sock(&sock->sk);
+
+		if (sock->dsap == LLCP_SAP_SDP &&
+				sock->sk.sk_state == LLCP_LISTEN)
+			goto enqueue;
+	} else {
+		u8 *sn;
+		size_t sn_len;
+
+		sn = nfc_llcp_connect_sn(skb, &sn_len);
+		if (sn == NULL) {
+			reason = LLCP_DM_NOBOUND;
+			goto fail;
+		}
+
+		pr_debug("Service name length %zu\n", sn_len);
+
+		mutex_lock(&local->socket_lock);
+		for (bound_sap = 0; bound_sap < LLCP_LOCAL_SAP_OFFSET;
+								bound_sap++) {
+			sock = local->sockets[bound_sap];
+			if (sock == NULL)
+				continue;
+
+			if (sock->service_name == NULL ||
+				sock->service_name_len == 0)
+					continue;
+
+			if (sock->service_name_len != sn_len)
+				continue;
+
+			if (sock->dsap == LLCP_SAP_SDP &&
+					sock->sk.sk_state == LLCP_LISTEN &&
+					!memcmp(sn, sock->service_name, sn_len)) {
+				pr_debug("Found service name at SAP %d\n",
+								bound_sap);
+				sock_hold(&sock->sk);
+				mutex_unlock(&local->socket_lock);
+
+				lock_sock(&sock->sk);
+
+				goto enqueue;
+			}
+		}
+
+	}
+
+	mutex_unlock(&local->socket_lock);
+
+	reason = LLCP_DM_NOBOUND;
+	goto fail;
+
+enqueue:
+	parent = &sock->sk;
+
+	if (sk_acceptq_is_full(parent)) {
+		reason = LLCP_DM_REJ;
+		release_sock(&sock->sk);
+		sock_put(&sock->sk);
+		goto fail;
+	}
+
+	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type,
+				     GFP_ATOMIC);
+	if (new_sk == NULL) {
+		reason = LLCP_DM_REJ;
+		release_sock(&sock->sk);
+		sock_put(&sock->sk);
+		goto fail;
+	}
+
+	new_sock = nfc_llcp_sock(new_sk);
+	new_sock->dev = local->dev;
+	new_sock->local = local;
+	new_sock->nfc_protocol = sock->nfc_protocol;
+	new_sock->ssap = bound_sap;
+	new_sock->dsap = ssap;
+	new_sock->parent = parent;
+
+	pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
+
+	list_add_tail(&new_sock->list, &sock->list);
+
+	nfc_llcp_accept_enqueue(&sock->sk, new_sk);
+
+	nfc_get_device(local->dev->idx);
+
+	new_sk->sk_state = LLCP_CONNECTED;
+
+	/* Wake the listening processes */
+	parent->sk_data_ready(parent, 0);
+
+	/* Send CC */
+	nfc_llcp_send_cc(new_sock);
+
+	release_sock(&sock->sk);
+	sock_put(&sock->sk);
+
+	return;
+
+fail:
+	/* Send DM */
+	nfc_llcp_send_dm(local, dsap, ssap, reason);
+
+	return;
+
+}
+
+static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
+				struct sk_buff *skb)
+{
+	struct nfc_llcp_sock *llcp_sock;
+	struct sock *sk;
+	u8 dsap, ssap, ptype, ns, nr;
+
+	ptype = nfc_llcp_ptype(skb);
+	dsap = nfc_llcp_dsap(skb);
+	ssap = nfc_llcp_ssap(skb);
+	ns = nfc_llcp_ns(skb);
+	nr = nfc_llcp_nr(skb);
+
+	pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
+
+	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
+	if (llcp_sock == NULL) {
+		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
+		return;
+	}
+
+	sk = &llcp_sock->sk;
+	lock_sock(sk);</