linux/net/nfc/nci/data.c
Jeff Kirsher 98b32decc8 nfc: Fix FSF address in file headers
Several files refer to an old address for the Free Software Foundation
in the file header comment.  Resolve by replacing the address with
the URL <http://www.gnu.org/licenses/> so that we do not have to keep
updating the header comments anytime the address changes.

CC: linux-wireless@vger.kernel.org
CC: Lauro Ramos Venancio <lauro.venancio@openbossa.org>
CC: Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
CC: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2013-12-11 10:56:21 -05:00

252 lines
6.0 KiB
C

/*
* The NFC Controller Interface is the communication protocol between an
* NFC Controller (NFCC) and a Device Host (DH).
*
* Copyright (C) 2011 Texas Instruments, Inc.
*
* Written by Ilan Elias <ilane@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation
*
* 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, see <http://www.gnu.org/licenses/>.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/wait.h>
#include <linux/bitops.h>
#include <linux/skbuff.h>
#include "../nfc.h"
#include <net/nfc/nci.h>
#include <net/nfc/nci_core.h>
#include <linux/nfc.h>
/* Complete data exchange transaction and forward skb to nfc core */
void nci_data_exchange_complete(struct nci_dev *ndev, struct sk_buff *skb,
int err)
{
data_exchange_cb_t cb = ndev->data_exchange_cb;
void *cb_context = ndev->data_exchange_cb_context;
pr_debug("len %d, err %d\n", skb ? skb->len : 0, err);
/* data exchange is complete, stop the data timer */
del_timer_sync(&ndev->data_timer);
clear_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
if (cb) {
ndev->data_exchange_cb = NULL;
ndev->data_exchange_cb_context = NULL;
/* forward skb to nfc core */
cb(cb_context, skb, err);
} else if (skb) {
pr_err("no rx callback, dropping rx data...\n");
/* no waiting callback, free skb */
kfree_skb(skb);
}
clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
}
/* ----------------- NCI TX Data ----------------- */
static inline void nci_push_data_hdr(struct nci_dev *ndev,
__u8 conn_id,
struct sk_buff *skb,
__u8 pbf)
{
struct nci_data_hdr *hdr;
int plen = skb->len;
hdr = (struct nci_data_hdr *) skb_push(skb, NCI_DATA_HDR_SIZE);
hdr->conn_id = conn_id;
hdr->rfu = 0;
hdr->plen = plen;
nci_mt_set((__u8 *)hdr, NCI_MT_DATA_PKT);
nci_pbf_set((__u8 *)hdr, pbf);
}
static int nci_queue_tx_data_frags(struct nci_dev *ndev,
__u8 conn_id,
struct sk_buff *skb) {
int total_len = skb->len;
unsigned char *data = skb->data;
unsigned long flags;
struct sk_buff_head frags_q;
struct sk_buff *skb_frag;
int frag_len;
int rc = 0;
pr_debug("conn_id 0x%x, total_len %d\n", conn_id, total_len);
__skb_queue_head_init(&frags_q);
while (total_len) {
frag_len =
min_t(int, total_len, ndev->max_data_pkt_payload_size);
skb_frag = nci_skb_alloc(ndev,
(NCI_DATA_HDR_SIZE + frag_len),
GFP_KERNEL);
if (skb_frag == NULL) {
rc = -ENOMEM;
goto free_exit;
}
skb_reserve(skb_frag, NCI_DATA_HDR_SIZE);
/* first, copy the data */
memcpy(skb_put(skb_frag, frag_len), data, frag_len);
/* second, set the header */
nci_push_data_hdr(ndev, conn_id, skb_frag,
((total_len == frag_len) ?
(NCI_PBF_LAST) : (NCI_PBF_CONT)));
__skb_queue_tail(&frags_q, skb_frag);
data += frag_len;
total_len -= frag_len;
pr_debug("frag_len %d, remaining total_len %d\n",
frag_len, total_len);
}
/* queue all fragments atomically */
spin_lock_irqsave(&ndev->tx_q.lock, flags);
while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
__skb_queue_tail(&ndev->tx_q, skb_frag);
spin_unlock_irqrestore(&ndev->tx_q.lock, flags);
/* free the original skb */
kfree_skb(skb);
goto exit;
free_exit:
while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
kfree_skb(skb_frag);
exit:
return rc;
}
/* Send NCI data */
int nci_send_data(struct nci_dev *ndev, __u8 conn_id, struct sk_buff *skb)
{
int rc = 0;
pr_debug("conn_id 0x%x, plen %d\n", conn_id, skb->len);
/* check if the packet need to be fragmented */
if (skb->len <= ndev->max_data_pkt_payload_size) {
/* no need to fragment packet */
nci_push_data_hdr(ndev, conn_id, skb, NCI_PBF_LAST);
skb_queue_tail(&ndev->tx_q, skb);
} else {
/* fragment packet and queue the fragments */
rc = nci_queue_tx_data_frags(ndev, conn_id, skb);
if (rc) {
pr_err("failed to fragment tx data packet\n");
goto free_exit;
}
}
queue_work(ndev->tx_wq, &ndev->tx_work);
goto exit;
free_exit:
kfree_skb(skb);
exit:
return rc;
}
/* ----------------- NCI RX Data ----------------- */
static void nci_add_rx_data_frag(struct nci_dev *ndev,
struct sk_buff *skb,
__u8 pbf)
{
int reassembly_len;
int err = 0;
if (ndev->rx_data_reassembly) {
reassembly_len = ndev->rx_data_reassembly->len;
/* first, make enough room for the already accumulated data */
if (skb_cow_head(skb, reassembly_len)) {
pr_err("error adding room for accumulated rx data\n");
kfree_skb(skb);
skb = NULL;
kfree_skb(ndev->rx_data_reassembly);
ndev->rx_data_reassembly = NULL;
err = -ENOMEM;
goto exit;
}
/* second, combine the two fragments */
memcpy(skb_push(skb, reassembly_len),
ndev->rx_data_reassembly->data,
reassembly_len);
/* third, free old reassembly */
kfree_skb(ndev->rx_data_reassembly);
ndev->rx_data_reassembly = NULL;
}
if (pbf == NCI_PBF_CONT) {
/* need to wait for next fragment, store skb and exit */
ndev->rx_data_reassembly = skb;
return;
}
exit:
nci_data_exchange_complete(ndev, skb, err);
}
/* Rx Data packet */
void nci_rx_data_packet(struct nci_dev *ndev, struct sk_buff *skb)
{
__u8 pbf = nci_pbf(skb->data);
pr_debug("len %d\n", skb->len);
pr_debug("NCI RX: MT=data, PBF=%d, conn_id=%d, plen=%d\n",
nci_pbf(skb->data),
nci_conn_id(skb->data),
nci_plen(skb->data));
/* strip the nci data header */
skb_pull(skb, NCI_DATA_HDR_SIZE);
if (ndev->target_active_prot == NFC_PROTO_MIFARE) {
/* frame I/F => remove the status byte */
pr_debug("NFC_PROTO_MIFARE => remove the status byte\n");
skb_trim(skb, (skb->len - 1));
}
nci_add_rx_data_frag(ndev, skb, pbf);
}