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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * The NFC Controller Interface is the communication protocol between an
4 * NFC Controller (NFCC) and a Device Host (DH).
5 *
6 * Copyright (C) 2011 Texas Instruments, Inc.
7 * Copyright (C) 2014 Marvell International Ltd.
8 *
9 * Written by Ilan Elias <ilane@ti.com>
10 */
11
12#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
13
14#include <linux/types.h>
15#include <linux/interrupt.h>
16#include <linux/wait.h>
17#include <linux/bitops.h>
18#include <linux/skbuff.h>
19
20#include "../nfc.h"
21#include <net/nfc/nci.h>
22#include <net/nfc/nci_core.h>
23#include <linux/nfc.h>
24
25/* Complete data exchange transaction and forward skb to nfc core */
26void nci_data_exchange_complete(struct nci_dev *ndev, struct sk_buff *skb,
27 __u8 conn_id, int err)
28{
29 const struct nci_conn_info *conn_info;
30 data_exchange_cb_t cb;
31 void *cb_context;
32
33 conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
34 if (!conn_info) {
35 kfree_skb(skb);
36 goto exit;
37 }
38
39 cb = conn_info->data_exchange_cb;
40 cb_context = conn_info->data_exchange_cb_context;
41
42 pr_debug("len %d, err %d\n", skb ? skb->len : 0, err);
43
44 /* data exchange is complete, stop the data timer */
45 del_timer_sync(&ndev->data_timer);
46 clear_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
47
48 if (cb) {
49 /* forward skb to nfc core */
50 cb(cb_context, skb, err);
51 } else if (skb) {
52 pr_err("no rx callback, dropping rx data...\n");
53
54 /* no waiting callback, free skb */
55 kfree_skb(skb);
56 }
57
58exit:
59 clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
60}
61
62/* ----------------- NCI TX Data ----------------- */
63
64static inline void nci_push_data_hdr(struct nci_dev *ndev,
65 __u8 conn_id,
66 struct sk_buff *skb,
67 __u8 pbf)
68{
69 struct nci_data_hdr *hdr;
70 int plen = skb->len;
71
72 hdr = skb_push(skb, NCI_DATA_HDR_SIZE);
73 hdr->conn_id = conn_id;
74 hdr->rfu = 0;
75 hdr->plen = plen;
76
77 nci_mt_set((__u8 *)hdr, NCI_MT_DATA_PKT);
78 nci_pbf_set((__u8 *)hdr, pbf);
79}
80
81int nci_conn_max_data_pkt_payload_size(struct nci_dev *ndev, __u8 conn_id)
82{
83 const struct nci_conn_info *conn_info;
84
85 conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
86 if (!conn_info)
87 return -EPROTO;
88
89 return conn_info->max_pkt_payload_len;
90}
91EXPORT_SYMBOL(nci_conn_max_data_pkt_payload_size);
92
93static int nci_queue_tx_data_frags(struct nci_dev *ndev,
94 __u8 conn_id,
95 struct sk_buff *skb) {
96 const struct nci_conn_info *conn_info;
97 int total_len = skb->len;
98 const unsigned char *data = skb->data;
99 unsigned long flags;
100 struct sk_buff_head frags_q;
101 struct sk_buff *skb_frag;
102 int frag_len;
103 int rc = 0;
104
105 pr_debug("conn_id 0x%x, total_len %d\n", conn_id, total_len);
106
107 conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
108 if (!conn_info) {
109 rc = -EPROTO;
110 goto exit;
111 }
112
113 __skb_queue_head_init(&frags_q);
114
115 while (total_len) {
116 frag_len =
117 min_t(int, total_len, conn_info->max_pkt_payload_len);
118
119 skb_frag = nci_skb_alloc(ndev,
120 (NCI_DATA_HDR_SIZE + frag_len),
121 GFP_ATOMIC);
122 if (skb_frag == NULL) {
123 rc = -ENOMEM;
124 goto free_exit;
125 }
126 skb_reserve(skb_frag, NCI_DATA_HDR_SIZE);
127
128 /* first, copy the data */
129 skb_put_data(skb_frag, data, frag_len);
130
131 /* second, set the header */
132 nci_push_data_hdr(ndev, conn_id, skb_frag,
133 ((total_len == frag_len) ?
134 (NCI_PBF_LAST) : (NCI_PBF_CONT)));
135
136 __skb_queue_tail(&frags_q, skb_frag);
137
138 data += frag_len;
139 total_len -= frag_len;
140
141 pr_debug("frag_len %d, remaining total_len %d\n",
142 frag_len, total_len);
143 }
144
145 /* queue all fragments atomically */
146 spin_lock_irqsave(&ndev->tx_q.lock, flags);
147
148 while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
149 __skb_queue_tail(&ndev->tx_q, skb_frag);
150
151 spin_unlock_irqrestore(&ndev->tx_q.lock, flags);
152
153 /* free the original skb */
154 kfree_skb(skb);
155
156 goto exit;
157
158free_exit:
159 while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
160 kfree_skb(skb_frag);
161
162exit:
163 return rc;
164}
165
166/* Send NCI data */
167int nci_send_data(struct nci_dev *ndev, __u8 conn_id, struct sk_buff *skb)
168{
169 const struct nci_conn_info *conn_info;
170 int rc = 0;
171
172 pr_debug("conn_id 0x%x, plen %d\n", conn_id, skb->len);
173
174 conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
175 if (!conn_info) {
176 rc = -EPROTO;
177 goto free_exit;
178 }
179
180 /* check if the packet need to be fragmented */
181 if (skb->len <= conn_info->max_pkt_payload_len) {
182 /* no need to fragment packet */
183 nci_push_data_hdr(ndev, conn_id, skb, NCI_PBF_LAST);
184
185 skb_queue_tail(&ndev->tx_q, skb);
186 } else {
187 /* fragment packet and queue the fragments */
188 rc = nci_queue_tx_data_frags(ndev, conn_id, skb);
189 if (rc) {
190 pr_err("failed to fragment tx data packet\n");
191 goto free_exit;
192 }
193 }
194
195 ndev->cur_conn_id = conn_id;
196 queue_work(ndev->tx_wq, &ndev->tx_work);
197
198 goto exit;
199
200free_exit:
201 kfree_skb(skb);
202
203exit:
204 return rc;
205}
206EXPORT_SYMBOL(nci_send_data);
207
208/* ----------------- NCI RX Data ----------------- */
209
210static void nci_add_rx_data_frag(struct nci_dev *ndev,
211 struct sk_buff *skb,
212 __u8 pbf, __u8 conn_id, __u8 status)
213{
214 int reassembly_len;
215 int err = 0;
216
217 if (status) {
218 err = status;
219 goto exit;
220 }
221
222 if (ndev->rx_data_reassembly) {
223 reassembly_len = ndev->rx_data_reassembly->len;
224
225 /* first, make enough room for the already accumulated data */
226 if (skb_cow_head(skb, reassembly_len)) {
227 pr_err("error adding room for accumulated rx data\n");
228
229 kfree_skb(skb);
230 skb = NULL;
231
232 kfree_skb(ndev->rx_data_reassembly);
233 ndev->rx_data_reassembly = NULL;
234
235 err = -ENOMEM;
236 goto exit;
237 }
238
239 /* second, combine the two fragments */
240 memcpy(skb_push(skb, reassembly_len),
241 ndev->rx_data_reassembly->data,
242 reassembly_len);
243
244 /* third, free old reassembly */
245 kfree_skb(ndev->rx_data_reassembly);
246 ndev->rx_data_reassembly = NULL;
247 }
248
249 if (pbf == NCI_PBF_CONT) {
250 /* need to wait for next fragment, store skb and exit */
251 ndev->rx_data_reassembly = skb;
252 return;
253 }
254
255exit:
256 if (ndev->nfc_dev->rf_mode == NFC_RF_TARGET) {
257 /* Data received in Target mode, forward to nfc core */
258 err = nfc_tm_data_received(ndev->nfc_dev, skb);
259 if (err)
260 pr_err("unable to handle received data\n");
261 } else {
262 nci_data_exchange_complete(ndev, skb, conn_id, err);
263 }
264}
265
266/* Rx Data packet */
267void nci_rx_data_packet(struct nci_dev *ndev, struct sk_buff *skb)
268{
269 __u8 pbf = nci_pbf(skb->data);
270 __u8 status = 0;
271 __u8 conn_id = nci_conn_id(skb->data);
272 const struct nci_conn_info *conn_info;
273
274 pr_debug("len %d\n", skb->len);
275
276 pr_debug("NCI RX: MT=data, PBF=%d, conn_id=%d, plen=%d\n",
277 nci_pbf(skb->data),
278 nci_conn_id(skb->data),
279 nci_plen(skb->data));
280
281 conn_info = nci_get_conn_info_by_conn_id(ndev, nci_conn_id(skb->data));
282 if (!conn_info) {
283 kfree_skb(skb);
284 return;
285 }
286
287 /* strip the nci data header */
288 skb_pull(skb, NCI_DATA_HDR_SIZE);
289
290 if (ndev->target_active_prot == NFC_PROTO_MIFARE ||
291 ndev->target_active_prot == NFC_PROTO_JEWEL ||
292 ndev->target_active_prot == NFC_PROTO_FELICA ||
293 ndev->target_active_prot == NFC_PROTO_ISO15693) {
294 /* frame I/F => remove the status byte */
295 pr_debug("frame I/F => remove the status byte\n");
296 status = skb->data[skb->len - 1];
297 skb_trim(skb, (skb->len - 1));
298 }
299
300 nci_add_rx_data_frag(ndev, skb, pbf, conn_id, nci_to_errno(status));
301}
1/*
2 * The NFC Controller Interface is the communication protocol between an
3 * NFC Controller (NFCC) and a Device Host (DH).
4 *
5 * Copyright (C) 2011 Texas Instruments, Inc.
6 * Copyright (C) 2014 Marvell International Ltd.
7 *
8 * Written by Ilan Elias <ilane@ti.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2
12 * as published by the Free Software Foundation
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, see <http://www.gnu.org/licenses/>.
21 *
22 */
23
24#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
25
26#include <linux/types.h>
27#include <linux/interrupt.h>
28#include <linux/wait.h>
29#include <linux/bitops.h>
30#include <linux/skbuff.h>
31
32#include "../nfc.h"
33#include <net/nfc/nci.h>
34#include <net/nfc/nci_core.h>
35#include <linux/nfc.h>
36
37/* Complete data exchange transaction and forward skb to nfc core */
38void nci_data_exchange_complete(struct nci_dev *ndev, struct sk_buff *skb,
39 __u8 conn_id, int err)
40{
41 struct nci_conn_info *conn_info;
42 data_exchange_cb_t cb;
43 void *cb_context;
44
45 conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
46 if (!conn_info) {
47 kfree_skb(skb);
48 goto exit;
49 }
50
51 cb = conn_info->data_exchange_cb;
52 cb_context = conn_info->data_exchange_cb_context;
53
54 pr_debug("len %d, err %d\n", skb ? skb->len : 0, err);
55
56 /* data exchange is complete, stop the data timer */
57 del_timer_sync(&ndev->data_timer);
58 clear_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
59
60 if (cb) {
61 /* forward skb to nfc core */
62 cb(cb_context, skb, err);
63 } else if (skb) {
64 pr_err("no rx callback, dropping rx data...\n");
65
66 /* no waiting callback, free skb */
67 kfree_skb(skb);
68 }
69
70exit:
71 clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
72}
73
74/* ----------------- NCI TX Data ----------------- */
75
76static inline void nci_push_data_hdr(struct nci_dev *ndev,
77 __u8 conn_id,
78 struct sk_buff *skb,
79 __u8 pbf)
80{
81 struct nci_data_hdr *hdr;
82 int plen = skb->len;
83
84 hdr = (struct nci_data_hdr *) skb_push(skb, NCI_DATA_HDR_SIZE);
85 hdr->conn_id = conn_id;
86 hdr->rfu = 0;
87 hdr->plen = plen;
88
89 nci_mt_set((__u8 *)hdr, NCI_MT_DATA_PKT);
90 nci_pbf_set((__u8 *)hdr, pbf);
91}
92
93int nci_conn_max_data_pkt_payload_size(struct nci_dev *ndev, __u8 conn_id)
94{
95 struct nci_conn_info *conn_info;
96
97 conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
98 if (!conn_info)
99 return -EPROTO;
100
101 return conn_info->max_pkt_payload_len;
102}
103EXPORT_SYMBOL(nci_conn_max_data_pkt_payload_size);
104
105static int nci_queue_tx_data_frags(struct nci_dev *ndev,
106 __u8 conn_id,
107 struct sk_buff *skb) {
108 struct nci_conn_info *conn_info;
109 int total_len = skb->len;
110 unsigned char *data = skb->data;
111 unsigned long flags;
112 struct sk_buff_head frags_q;
113 struct sk_buff *skb_frag;
114 int frag_len;
115 int rc = 0;
116
117 pr_debug("conn_id 0x%x, total_len %d\n", conn_id, total_len);
118
119 conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
120 if (!conn_info) {
121 rc = -EPROTO;
122 goto free_exit;
123 }
124
125 __skb_queue_head_init(&frags_q);
126
127 while (total_len) {
128 frag_len =
129 min_t(int, total_len, conn_info->max_pkt_payload_len);
130
131 skb_frag = nci_skb_alloc(ndev,
132 (NCI_DATA_HDR_SIZE + frag_len),
133 GFP_KERNEL);
134 if (skb_frag == NULL) {
135 rc = -ENOMEM;
136 goto free_exit;
137 }
138 skb_reserve(skb_frag, NCI_DATA_HDR_SIZE);
139
140 /* first, copy the data */
141 memcpy(skb_put(skb_frag, frag_len), data, frag_len);
142
143 /* second, set the header */
144 nci_push_data_hdr(ndev, conn_id, skb_frag,
145 ((total_len == frag_len) ?
146 (NCI_PBF_LAST) : (NCI_PBF_CONT)));
147
148 __skb_queue_tail(&frags_q, skb_frag);
149
150 data += frag_len;
151 total_len -= frag_len;
152
153 pr_debug("frag_len %d, remaining total_len %d\n",
154 frag_len, total_len);
155 }
156
157 /* queue all fragments atomically */
158 spin_lock_irqsave(&ndev->tx_q.lock, flags);
159
160 while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
161 __skb_queue_tail(&ndev->tx_q, skb_frag);
162
163 spin_unlock_irqrestore(&ndev->tx_q.lock, flags);
164
165 /* free the original skb */
166 kfree_skb(skb);
167
168 goto exit;
169
170free_exit:
171 while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
172 kfree_skb(skb_frag);
173
174exit:
175 return rc;
176}
177
178/* Send NCI data */
179int nci_send_data(struct nci_dev *ndev, __u8 conn_id, struct sk_buff *skb)
180{
181 struct nci_conn_info *conn_info;
182 int rc = 0;
183
184 pr_debug("conn_id 0x%x, plen %d\n", conn_id, skb->len);
185
186 conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
187 if (!conn_info) {
188 rc = -EPROTO;
189 goto free_exit;
190 }
191
192 /* check if the packet need to be fragmented */
193 if (skb->len <= conn_info->max_pkt_payload_len) {
194 /* no need to fragment packet */
195 nci_push_data_hdr(ndev, conn_id, skb, NCI_PBF_LAST);
196
197 skb_queue_tail(&ndev->tx_q, skb);
198 } else {
199 /* fragment packet and queue the fragments */
200 rc = nci_queue_tx_data_frags(ndev, conn_id, skb);
201 if (rc) {
202 pr_err("failed to fragment tx data packet\n");
203 goto free_exit;
204 }
205 }
206
207 ndev->cur_conn_id = conn_id;
208 queue_work(ndev->tx_wq, &ndev->tx_work);
209
210 goto exit;
211
212free_exit:
213 kfree_skb(skb);
214
215exit:
216 return rc;
217}
218EXPORT_SYMBOL(nci_send_data);
219
220/* ----------------- NCI RX Data ----------------- */
221
222static void nci_add_rx_data_frag(struct nci_dev *ndev,
223 struct sk_buff *skb,
224 __u8 pbf, __u8 conn_id, __u8 status)
225{
226 int reassembly_len;
227 int err = 0;
228
229 if (status) {
230 err = status;
231 goto exit;
232 }
233
234 if (ndev->rx_data_reassembly) {
235 reassembly_len = ndev->rx_data_reassembly->len;
236
237 /* first, make enough room for the already accumulated data */
238 if (skb_cow_head(skb, reassembly_len)) {
239 pr_err("error adding room for accumulated rx data\n");
240
241 kfree_skb(skb);
242 skb = NULL;
243
244 kfree_skb(ndev->rx_data_reassembly);
245 ndev->rx_data_reassembly = NULL;
246
247 err = -ENOMEM;
248 goto exit;
249 }
250
251 /* second, combine the two fragments */
252 memcpy(skb_push(skb, reassembly_len),
253 ndev->rx_data_reassembly->data,
254 reassembly_len);
255
256 /* third, free old reassembly */
257 kfree_skb(ndev->rx_data_reassembly);
258 ndev->rx_data_reassembly = NULL;
259 }
260
261 if (pbf == NCI_PBF_CONT) {
262 /* need to wait for next fragment, store skb and exit */
263 ndev->rx_data_reassembly = skb;
264 return;
265 }
266
267exit:
268 if (ndev->nfc_dev->rf_mode == NFC_RF_TARGET) {
269 /* Data received in Target mode, forward to nfc core */
270 err = nfc_tm_data_received(ndev->nfc_dev, skb);
271 if (err)
272 pr_err("unable to handle received data\n");
273 } else {
274 nci_data_exchange_complete(ndev, skb, conn_id, err);
275 }
276}
277
278/* Rx Data packet */
279void nci_rx_data_packet(struct nci_dev *ndev, struct sk_buff *skb)
280{
281 __u8 pbf = nci_pbf(skb->data);
282 __u8 status = 0;
283 __u8 conn_id = nci_conn_id(skb->data);
284 struct nci_conn_info *conn_info;
285
286 pr_debug("len %d\n", skb->len);
287
288 pr_debug("NCI RX: MT=data, PBF=%d, conn_id=%d, plen=%d\n",
289 nci_pbf(skb->data),
290 nci_conn_id(skb->data),
291 nci_plen(skb->data));
292
293 conn_info = nci_get_conn_info_by_conn_id(ndev, nci_conn_id(skb->data));
294 if (!conn_info)
295 return;
296
297 /* strip the nci data header */
298 skb_pull(skb, NCI_DATA_HDR_SIZE);
299
300 if (ndev->target_active_prot == NFC_PROTO_MIFARE ||
301 ndev->target_active_prot == NFC_PROTO_JEWEL ||
302 ndev->target_active_prot == NFC_PROTO_FELICA ||
303 ndev->target_active_prot == NFC_PROTO_ISO15693) {
304 /* frame I/F => remove the status byte */
305 pr_debug("frame I/F => remove the status byte\n");
306 status = skb->data[skb->len - 1];
307 skb_trim(skb, (skb->len - 1));
308 }
309
310 nci_add_rx_data_frag(ndev, skb, pbf, conn_id, nci_to_errno(status));
311}