NFC: Move LLCP code to the NFC top level diirectory

And stop making it optional. LLCP is a fundamental part of the NFC
specifications and making it optional does not make much sense.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 817 insertions, 0 deletions

diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c
new file mode 100644
index 000000000000..c1b23eef83ca
--- /dev/null
+++ b/net/nfc/llcp_commands.c
@@ -0,0 +1,817 @@
+/*
+ * 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 *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_MIUX:
+                        sock->remote_miu = llcp_tlv_miux(tlv) + 128;
+                        break;
+                case LLCP_TLV_RW:
+                        sock->remote_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 miu %d\n", sock,
+                 sock->remote_rw, sock->remote_miu);
+
+        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;
+
+        pr_debug("Sending DISC\n");
+
+        local = sock->local;
+        if (local == NULL)
+                return -ENODEV;
+
+        dev = sock->dev;
+        if (dev == NULL)
+                return -ENODEV;
+
+        skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0);
+        if (skb == NULL)
+                return -ENOMEM;
+
+        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);
+
+        __net_timestamp(skb);
+
+        nfc_llcp_send_to_raw_sock(local, skb, NFC_LLCP_DIRECTION_TX);
+
+        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;
+        int err;
+        u16 size = 0, miux;
+
+        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;
+        }
+
+        /* If the socket parameters are not set, use the local ones */
+        miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
+                local->miux : sock->miux;
+        rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
+
+        miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
+                                      &miux_tlv_length);
+        size += miux_tlv_length;
+
+        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;
+        int err;
+        u16 size = 0, miux;
+
+        pr_debug("Sending CC\n");
+
+        local = sock->local;
+        if (local == NULL)
+                return -ENODEV;
+
+        /* If the socket parameters are not set, use the local ones */
+        miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
+                local->miux : sock->miux;
+        rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
+
+        miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
+                                      &miux_tlv_length);
+        size += miux_tlv_length;
+
+        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;
+}
+
+static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local,
+                                             size_t tlv_length)
+{
+        struct sk_buff *skb;
+        struct nfc_dev *dev;
+        u16 size = 0;
+
+        if (local == NULL)
+                return ERR_PTR(-ENODEV);
+
+        dev = local->dev;
+        if (dev == NULL)
+                return ERR_PTR(-ENODEV);
+
+        size += LLCP_HEADER_SIZE;
+        size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
+        size += tlv_length;
+
+        skb = alloc_skb(size, GFP_KERNEL);
+        if (skb == NULL)
+                return ERR_PTR(-ENOMEM);
+
+        skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
+
+        skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL);
+
+        return skb;
+}
+
+int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local,
+                            struct hlist_head *tlv_list, size_t tlvs_len)
+{
+        struct nfc_llcp_sdp_tlv *sdp;
+        struct hlist_node *n;
+        struct sk_buff *skb;
+
+        skb = nfc_llcp_allocate_snl(local, tlvs_len);
+        if (IS_ERR(skb))
+                return PTR_ERR(skb);
+
+        hlist_for_each_entry_safe(sdp, n, tlv_list, node) {
+                memcpy(skb_put(skb, sdp->tlv_len), sdp->tlv, sdp->tlv_len);
+
+                hlist_del(&sdp->node);
+
+                nfc_llcp_free_sdp_tlv(sdp);
+        }
+
+        skb_queue_tail(&local->tx_queue, skb);
+
+        return 0;
+}
+
+int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local,
+                            struct hlist_head *tlv_list, size_t tlvs_len)
+{
+        struct nfc_llcp_sdp_tlv *sdreq;
+        struct hlist_node *n;
+        struct sk_buff *skb;
+
+        skb = nfc_llcp_allocate_snl(local, tlvs_len);
+        if (IS_ERR(skb))
+                return PTR_ERR(skb);
+
+        mutex_lock(&local->sdreq_lock);
+
+        if (hlist_empty(&local->pending_sdreqs))
+                mod_timer(&local->sdreq_timer,
+                          jiffies + msecs_to_jiffies(3 * local->remote_lto));
+
+        hlist_for_each_entry_safe(sdreq, n, tlv_list, node) {
+                pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri);
+
+                memcpy(skb_put(skb, sdreq->tlv_len), sdreq->tlv,
+                       sdreq->tlv_len);
+
+                hlist_del(&sdreq->node);
+
+                hlist_add_head(&sdreq->node, &local->pending_sdreqs);
+        }
+
+        mutex_unlock(&local->sdreq_lock);
+
+        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, 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;
+        u16 remote_miu;
+
+        pr_debug("Send I frame len %zd\n", len);
+
+        local = sock->local;
+        if (local == NULL)
+                return -ENODEV;
+
+        /* Remote is ready but has not acknowledged our frames */
+        if((sock->remote_ready &&
+            skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw &&
+            skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
+                pr_err("Pending queue is full %d frames\n",
+                       skb_queue_len(&sock->tx_pending_queue));
+                return -ENOBUFS;
+        }
+
+        /* Remote is not ready and we've been queueing enough frames */
+        if ((!sock->remote_ready &&
+             skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
+                pr_err("Tx queue is full %d frames\n",
+                       skb_queue_len(&sock->tx_queue));
+                return -ENOBUFS;
+        }
+
+        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;
+
+        do {
+                remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
+                                local->remote_miu : sock->remote_miu;
+
+                frag_len = min_t(size_t, 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);
+
+                if (likely(frag_len > 0))
+                        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;
+        } while (remaining_len > 0);
+
+        kfree(msg_data);
+
+        return len;
+}
+
+int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
+                           struct msghdr *msg, size_t len)
+{
+        struct sk_buff *pdu;
+        struct nfc_llcp_local *local;
+        size_t frag_len = 0, remaining_len;
+        u8 *msg_ptr, *msg_data;
+        u16 remote_miu;
+        int err;
+
+        pr_debug("Send UI 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;
+
+        do {
+                remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
+                                local->remote_miu : sock->remote_miu;
+
+                frag_len = min_t(size_t, remote_miu, remaining_len);
+
+                pr_debug("Fragment %zd bytes remaining %zd",
+                         frag_len, remaining_len);
+
+                pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
+                                         frag_len + LLCP_HEADER_SIZE, &err);
+                if (pdu == NULL) {
+                        pr_err("Could not allocate PDU\n");
+                        continue;
+                }
+
+                pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI);
+
+                if (likely(frag_len > 0))
+                        memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len);
+
+                /* No need to check for the peer RW for UI frames */
+                skb_queue_tail(&local->tx_queue, pdu);
+
+                remaining_len -= frag_len;
+                msg_ptr += frag_len;
+        } while (remaining_len > 0);
+
+        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;
+}