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-rw-r--r--net/nfc/llcp_commands.c815
1 files changed, 815 insertions, 0 deletions
diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c
new file mode 100644
index 000000000..e2680a3be
--- /dev/null
+++ b/net/nfc/llcp_commands.c
@@ -0,0 +1,815 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2011 Intel Corporation. All rights reserved.
+ */
+
+#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 const 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(const u8 *tlv, u8 type)
+{
+ if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
+ return 0;
+
+ return tlv[2];
+}
+
+static u16 llcp_tlv16(const 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(const u8 *tlv)
+{
+ return llcp_tlv8(tlv, LLCP_TLV_VERSION);
+}
+
+static u16 llcp_tlv_miux(const u8 *tlv)
+{
+ return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff;
+}
+
+static u16 llcp_tlv_wks(const u8 *tlv)
+{
+ return llcp_tlv16(tlv, LLCP_TLV_WKS);
+}
+
+static u16 llcp_tlv_lto(const u8 *tlv)
+{
+ return llcp_tlv8(tlv, LLCP_TLV_LTO);
+}
+
+static u8 llcp_tlv_opt(const u8 *tlv)
+{
+ return llcp_tlv8(tlv, LLCP_TLV_OPT);
+}
+
+static u8 llcp_tlv_rw(const u8 *tlv)
+{
+ return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf;
+}
+
+u8 *nfc_llcp_build_tlv(u8 type, const 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, const char *uri,
+ size_t uri_len)
+{
+ struct nfc_llcp_sdp_tlv *sdreq;
+
+ pr_debug("uri: %s, len: %zu\n", uri, uri_len);
+
+ /* sdreq->tlv_len is u8, takes uri_len, + 3 for header, + 1 for NULL */
+ if (WARN_ON_ONCE(uri_len > U8_MAX - 4))
+ return NULL;
+
+ 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,
+ const u8 *tlv_array, u16 tlv_array_len)
+{
+ const u8 *tlv = tlv_array;
+ u8 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,
+ const u8 *tlv_array, u16 tlv_array_len)
+{
+ const u8 *tlv = tlv_array;
+ u8 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]);
+
+ skb_put_data(pdu, header, LLCP_HEADER_SIZE);
+
+ return pdu;
+}
+
+static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, const u8 *tlv,
+ u8 tlv_length)
+{
+ /* XXX Add an skb length check */
+
+ if (tlv == NULL)
+ return NULL;
+
+ skb_put_data(pdu, 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_send_disconnect(struct nfc_llcp_sock *sock)
+{
+ struct sk_buff *skb;
+ struct nfc_dev *dev;
+ struct nfc_llcp_local *local;
+
+ 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;
+ int err;
+
+ 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) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ 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_DIRECTION_TX);
+
+ err = nfc_data_exchange(dev, local->target_idx, skb,
+ nfc_llcp_recv, local);
+out:
+ nfc_llcp_local_put(local);
+ return err;
+}
+
+int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
+{
+ struct nfc_llcp_local *local;
+ struct sk_buff *skb;
+ const u8 *service_name_tlv = NULL;
+ const u8 *miux_tlv = NULL;
+ const u8 *rw_tlv = NULL;
+ u8 service_name_tlv_length = 0;
+ u8 miux_tlv_length, rw_tlv_length, rw;
+ int err;
+ u16 size = 0;
+ __be16 miux;
+
+ 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);
+ if (!service_name_tlv) {
+ err = -ENOMEM;
+ goto error_tlv;
+ }
+ 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);
+ if (!miux_tlv) {
+ err = -ENOMEM;
+ goto error_tlv;
+ }
+ size += miux_tlv_length;
+
+ rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
+ if (!rw_tlv) {
+ err = -ENOMEM;
+ goto error_tlv;
+ }
+ 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;
+ }
+
+ llcp_add_tlv(skb, service_name_tlv, service_name_tlv_length);
+ llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
+ llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
+
+ skb_queue_tail(&local->tx_queue, skb);
+
+ err = 0;
+
+error_tlv:
+ if (err)
+ 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;
+ const u8 *miux_tlv = NULL;
+ const u8 *rw_tlv = NULL;
+ u8 miux_tlv_length, rw_tlv_length, rw;
+ int err;
+ u16 size = 0;
+ __be16 miux;
+
+ 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);
+ if (!miux_tlv) {
+ err = -ENOMEM;
+ goto error_tlv;
+ }
+ size += miux_tlv_length;
+
+ rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
+ if (!rw_tlv) {
+ err = -ENOMEM;
+ goto error_tlv;
+ }
+ size += rw_tlv_length;
+
+ skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);
+ if (skb == NULL) {
+ err = -ENOMEM;
+ goto error_tlv;
+ }
+
+ llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
+ llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
+
+ skb_queue_tail(&local->tx_queue, skb);
+
+ err = 0;
+
+error_tlv:
+ if (err)
+ 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) {
+ skb_put_data(skb, 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);
+
+ skb_put_data(skb, 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);
+
+ skb_put_data(skb, &reason, 1);
+
+ 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 = kmalloc(len, GFP_USER | __GFP_NOWARN);
+ if (msg_data == NULL)
+ return -ENOMEM;
+
+ if (memcpy_from_msg(msg_data, msg, len)) {
+ kfree(msg_data);
+ return -EFAULT;
+ }
+
+ remaining_len = len;
+ msg_ptr = msg_data;
+
+ do {
+ remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
+ LLCP_DEFAULT_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) {
+ kfree(msg_data);
+ return -ENOMEM;
+ }
+
+ skb_put(pdu, LLCP_SEQUENCE_SIZE);
+
+ if (likely(frag_len > 0))
+ skb_put_data(pdu, 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 = kmalloc(len, GFP_USER | __GFP_NOWARN);
+ if (msg_data == NULL)
+ return -ENOMEM;
+
+ if (memcpy_from_msg(msg_data, msg, 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, 0,
+ frag_len + LLCP_HEADER_SIZE, &err);
+ if (pdu == NULL) {
+ pr_err("Could not allocate PDU (error=%d)\n", err);
+ len -= remaining_len;
+ if (len == 0)
+ len = err;
+ break;
+ }
+
+ pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI);
+
+ if (likely(frag_len > 0))
+ skb_put_data(pdu, 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;
+}