xref: /openbmc/linux/drivers/nfc/st21nfca/se.c (revision abfbd895)
1 /*
2  * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, see <http://www.gnu.org/licenses/>.
15  */
16 
17 #include <net/nfc/hci.h>
18 
19 #include "st21nfca.h"
20 
21 #define ST21NFCA_EVT_UICC_ACTIVATE		0x10
22 #define ST21NFCA_EVT_UICC_DEACTIVATE		0x13
23 #define ST21NFCA_EVT_SE_HARD_RESET		0x20
24 #define ST21NFCA_EVT_SE_SOFT_RESET		0x11
25 #define ST21NFCA_EVT_SE_END_OF_APDU_TRANSFER	0x21
26 #define ST21NFCA_EVT_SE_ACTIVATE		0x22
27 #define ST21NFCA_EVT_SE_DEACTIVATE		0x23
28 
29 #define ST21NFCA_EVT_TRANSMIT_DATA		0x10
30 #define ST21NFCA_EVT_WTX_REQUEST		0x11
31 
32 #define ST21NFCA_EVT_CONNECTIVITY		0x10
33 #define ST21NFCA_EVT_TRANSACTION		0x12
34 
35 #define ST21NFCA_ESE_HOST_ID			0xc0
36 
37 #define ST21NFCA_SE_TO_HOT_PLUG			1000
38 /* Connectivity pipe only */
39 #define ST21NFCA_SE_COUNT_PIPE_UICC		0x01
40 /* Connectivity + APDU Reader pipe */
41 #define ST21NFCA_SE_COUNT_PIPE_EMBEDDED	0x02
42 
43 #define ST21NFCA_SE_MODE_OFF			0x00
44 #define ST21NFCA_SE_MODE_ON				0x01
45 
46 #define ST21NFCA_PARAM_ATR				0x01
47 #define ST21NFCA_ATR_DEFAULT_BWI		0x04
48 
49 /*
50  * WT = 2^BWI/10[s], convert into msecs and add a secure
51  * room by increasing by 2 this timeout
52  */
53 #define ST21NFCA_BWI_TO_TIMEOUT(x)		((1 << x) * 200)
54 #define ST21NFCA_ATR_GET_Y_FROM_TD(x)	(x >> 4)
55 
56 /* If TA is present bit 0 is set */
57 #define ST21NFCA_ATR_TA_PRESENT(x) (x & 0x01)
58 /* If TB is present bit 1 is set */
59 #define ST21NFCA_ATR_TB_PRESENT(x) (x & 0x02)
60 
61 static u8 st21nfca_se_get_bwi(struct nfc_hci_dev *hdev)
62 {
63 	int i;
64 	u8 td;
65 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
66 
67 	/* Bits 8 to 5 of the first TB for T=1 encode BWI from zero to nine */
68 	for (i = 1; i < ST21NFCA_ESE_MAX_LENGTH; i++) {
69 		td = ST21NFCA_ATR_GET_Y_FROM_TD(info->se_info.atr[i]);
70 		if (ST21NFCA_ATR_TA_PRESENT(td))
71 			i++;
72 		if (ST21NFCA_ATR_TB_PRESENT(td)) {
73 			i++;
74 			return info->se_info.atr[i] >> 4;
75 		}
76 	}
77 	return ST21NFCA_ATR_DEFAULT_BWI;
78 }
79 
80 static void st21nfca_se_get_atr(struct nfc_hci_dev *hdev)
81 {
82 	int r;
83 	struct sk_buff *skb;
84 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
85 
86 	r = nfc_hci_get_param(hdev, ST21NFCA_APDU_READER_GATE,
87 			ST21NFCA_PARAM_ATR, &skb);
88 	if (r < 0)
89 		return;
90 
91 	if (skb->len <= ST21NFCA_ESE_MAX_LENGTH) {
92 		memcpy(info->se_info.atr, skb->data, skb->len);
93 		info->se_info.wt_timeout =
94 			ST21NFCA_BWI_TO_TIMEOUT(st21nfca_se_get_bwi(hdev));
95 	}
96 	kfree_skb(skb);
97 }
98 
99 static int st21nfca_hci_control_se(struct nfc_hci_dev *hdev, u32 se_idx,
100 				u8 state)
101 {
102 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
103 	int r, i;
104 	struct sk_buff *sk_host_list;
105 	u8 se_event, host_id;
106 
107 	switch (se_idx) {
108 	case NFC_HCI_UICC_HOST_ID:
109 		se_event = (state == ST21NFCA_SE_MODE_ON ?
110 					ST21NFCA_EVT_UICC_ACTIVATE :
111 					ST21NFCA_EVT_UICC_DEACTIVATE);
112 
113 		info->se_info.count_pipes = 0;
114 		info->se_info.expected_pipes = ST21NFCA_SE_COUNT_PIPE_UICC;
115 		break;
116 	case ST21NFCA_ESE_HOST_ID:
117 		se_event = (state == ST21NFCA_SE_MODE_ON ?
118 					ST21NFCA_EVT_SE_ACTIVATE :
119 					ST21NFCA_EVT_SE_DEACTIVATE);
120 
121 		info->se_info.count_pipes = 0;
122 		info->se_info.expected_pipes = ST21NFCA_SE_COUNT_PIPE_EMBEDDED;
123 		break;
124 	default:
125 		return -EINVAL;
126 	}
127 
128 	/*
129 	 * Wait for an EVT_HOT_PLUG in order to
130 	 * retrieve a relevant host list.
131 	 */
132 	reinit_completion(&info->se_info.req_completion);
133 	r = nfc_hci_send_event(hdev, ST21NFCA_DEVICE_MGNT_GATE, se_event,
134 			       NULL, 0);
135 	if (r < 0)
136 		return r;
137 
138 	mod_timer(&info->se_info.se_active_timer, jiffies +
139 		msecs_to_jiffies(ST21NFCA_SE_TO_HOT_PLUG));
140 	info->se_info.se_active = true;
141 
142 	/* Ignore return value and check in any case the host_list */
143 	wait_for_completion_interruptible(&info->se_info.req_completion);
144 
145 	r = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,
146 			NFC_HCI_ADMIN_HOST_LIST,
147 			&sk_host_list);
148 	if (r < 0)
149 		return r;
150 
151 	for (i = 0; i < sk_host_list->len &&
152 		sk_host_list->data[i] != se_idx; i++)
153 		;
154 	host_id = sk_host_list->data[i];
155 	kfree_skb(sk_host_list);
156 
157 	if (state == ST21NFCA_SE_MODE_ON && host_id == se_idx)
158 		return se_idx;
159 	else if (state == ST21NFCA_SE_MODE_OFF && host_id != se_idx)
160 		return se_idx;
161 
162 	return -1;
163 }
164 
165 int st21nfca_hci_discover_se(struct nfc_hci_dev *hdev)
166 {
167 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
168 	int se_count = 0;
169 
170 	if (test_bit(ST21NFCA_FACTORY_MODE, &hdev->quirks))
171 		return 0;
172 
173 	if (info->se_status->is_uicc_present) {
174 		nfc_add_se(hdev->ndev, NFC_HCI_UICC_HOST_ID, NFC_SE_UICC);
175 		se_count++;
176 	}
177 
178 	if (info->se_status->is_ese_present) {
179 		nfc_add_se(hdev->ndev, ST21NFCA_ESE_HOST_ID, NFC_SE_EMBEDDED);
180 		se_count++;
181 	}
182 
183 	return !se_count;
184 }
185 EXPORT_SYMBOL(st21nfca_hci_discover_se);
186 
187 int st21nfca_hci_enable_se(struct nfc_hci_dev *hdev, u32 se_idx)
188 {
189 	int r;
190 
191 	/*
192 	 * According to upper layer, se_idx == NFC_SE_UICC when
193 	 * info->se_status->is_uicc_enable is true should never happen.
194 	 * Same for eSE.
195 	 */
196 	r = st21nfca_hci_control_se(hdev, se_idx, ST21NFCA_SE_MODE_ON);
197 	if (r == ST21NFCA_ESE_HOST_ID) {
198 		st21nfca_se_get_atr(hdev);
199 		r = nfc_hci_send_event(hdev, ST21NFCA_APDU_READER_GATE,
200 				ST21NFCA_EVT_SE_SOFT_RESET, NULL, 0);
201 		if (r < 0)
202 			return r;
203 	} else if (r < 0) {
204 		/*
205 		 * The activation tentative failed, the secure element
206 		 * is not connected. Remove from the list.
207 		 */
208 		nfc_remove_se(hdev->ndev, se_idx);
209 		return r;
210 	}
211 
212 	return 0;
213 }
214 EXPORT_SYMBOL(st21nfca_hci_enable_se);
215 
216 int st21nfca_hci_disable_se(struct nfc_hci_dev *hdev, u32 se_idx)
217 {
218 	int r;
219 
220 	/*
221 	 * According to upper layer, se_idx == NFC_SE_UICC when
222 	 * info->se_status->is_uicc_enable is true should never happen
223 	 * Same for eSE.
224 	 */
225 	r = st21nfca_hci_control_se(hdev, se_idx, ST21NFCA_SE_MODE_OFF);
226 	if (r < 0)
227 		return r;
228 
229 	return 0;
230 }
231 EXPORT_SYMBOL(st21nfca_hci_disable_se);
232 
233 int st21nfca_hci_se_io(struct nfc_hci_dev *hdev, u32 se_idx,
234 			u8 *apdu, size_t apdu_length,
235 			se_io_cb_t cb, void *cb_context)
236 {
237 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
238 
239 	pr_debug("se_io %x\n", se_idx);
240 
241 	switch (se_idx) {
242 	case ST21NFCA_ESE_HOST_ID:
243 		info->se_info.cb = cb;
244 		info->se_info.cb_context = cb_context;
245 		mod_timer(&info->se_info.bwi_timer, jiffies +
246 			  msecs_to_jiffies(info->se_info.wt_timeout));
247 		info->se_info.bwi_active = true;
248 		return nfc_hci_send_event(hdev, ST21NFCA_APDU_READER_GATE,
249 					ST21NFCA_EVT_TRANSMIT_DATA,
250 					apdu, apdu_length);
251 	default:
252 		return -ENODEV;
253 	}
254 }
255 EXPORT_SYMBOL(st21nfca_hci_se_io);
256 
257 static void st21nfca_se_wt_timeout(unsigned long data)
258 {
259 	/*
260 	 * No answer from the secure element
261 	 * within the defined timeout.
262 	 * Let's send a reset request as recovery procedure.
263 	 * According to the situation, we first try to send a software reset
264 	 * to the secure element. If the next command is still not
265 	 * answering in time, we send to the CLF a secure element hardware
266 	 * reset request.
267 	 */
268 	/* hardware reset managed through VCC_UICC_OUT power supply */
269 	u8 param = 0x01;
270 	struct st21nfca_hci_info *info = (struct st21nfca_hci_info *) data;
271 
272 	pr_debug("\n");
273 
274 	info->se_info.bwi_active = false;
275 
276 	if (!info->se_info.xch_error) {
277 		info->se_info.xch_error = true;
278 		nfc_hci_send_event(info->hdev, ST21NFCA_APDU_READER_GATE,
279 				ST21NFCA_EVT_SE_SOFT_RESET, NULL, 0);
280 	} else {
281 		info->se_info.xch_error = false;
282 		nfc_hci_send_event(info->hdev, ST21NFCA_DEVICE_MGNT_GATE,
283 				ST21NFCA_EVT_SE_HARD_RESET, &param, 1);
284 	}
285 	info->se_info.cb(info->se_info.cb_context, NULL, 0, -ETIME);
286 }
287 
288 static void st21nfca_se_activation_timeout(unsigned long data)
289 {
290 	struct st21nfca_hci_info *info = (struct st21nfca_hci_info *) data;
291 
292 	pr_debug("\n");
293 
294 	info->se_info.se_active = false;
295 
296 	complete(&info->se_info.req_completion);
297 }
298 
299 /*
300  * Returns:
301  * <= 0: driver handled the event, skb consumed
302  *    1: driver does not handle the event, please do standard processing
303  */
304 int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
305 				u8 event, struct sk_buff *skb)
306 {
307 	int r = 0;
308 	struct device *dev = &hdev->ndev->dev;
309 	struct nfc_evt_transaction *transaction;
310 
311 	pr_debug("connectivity gate event: %x\n", event);
312 
313 	switch (event) {
314 	case ST21NFCA_EVT_CONNECTIVITY:
315 		break;
316 	case ST21NFCA_EVT_TRANSACTION:
317 		/*
318 		 * According to specification etsi 102 622
319 		 * 11.2.2.4 EVT_TRANSACTION Table 52
320 		 * Description	Tag	Length
321 		 * AID		81	5 to 16
322 		 * PARAMETERS	82	0 to 255
323 		 */
324 		if (skb->len < NFC_MIN_AID_LENGTH + 2 &&
325 		    skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG)
326 			return -EPROTO;
327 
328 		transaction = (struct nfc_evt_transaction *)devm_kzalloc(dev,
329 						   skb->len - 2, GFP_KERNEL);
330 
331 		transaction->aid_len = skb->data[1];
332 		memcpy(transaction->aid, &skb->data[2],
333 		       transaction->aid_len);
334 
335 		/* Check next byte is PARAMETERS tag (82) */
336 		if (skb->data[transaction->aid_len + 2] !=
337 		    NFC_EVT_TRANSACTION_PARAMS_TAG)
338 			return -EPROTO;
339 
340 		transaction->params_len = skb->data[transaction->aid_len + 3];
341 		memcpy(transaction->params, skb->data +
342 		       transaction->aid_len + 4, transaction->params_len);
343 
344 		r = nfc_se_transaction(hdev->ndev, host, transaction);
345 		break;
346 	default:
347 		nfc_err(&hdev->ndev->dev, "Unexpected event on connectivity gate\n");
348 		return 1;
349 	}
350 	kfree_skb(skb);
351 	return r;
352 }
353 EXPORT_SYMBOL(st21nfca_connectivity_event_received);
354 
355 int st21nfca_apdu_reader_event_received(struct nfc_hci_dev *hdev,
356 					u8 event, struct sk_buff *skb)
357 {
358 	int r = 0;
359 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
360 
361 	pr_debug("apdu reader gate event: %x\n", event);
362 
363 	switch (event) {
364 	case ST21NFCA_EVT_TRANSMIT_DATA:
365 		del_timer_sync(&info->se_info.bwi_timer);
366 		info->se_info.bwi_active = false;
367 		r = nfc_hci_send_event(hdev, ST21NFCA_DEVICE_MGNT_GATE,
368 				ST21NFCA_EVT_SE_END_OF_APDU_TRANSFER, NULL, 0);
369 		if (r < 0)
370 			goto exit;
371 
372 		info->se_info.cb(info->se_info.cb_context,
373 			skb->data, skb->len, 0);
374 		break;
375 	case ST21NFCA_EVT_WTX_REQUEST:
376 		mod_timer(&info->se_info.bwi_timer, jiffies +
377 				msecs_to_jiffies(info->se_info.wt_timeout));
378 		break;
379 	default:
380 		nfc_err(&hdev->ndev->dev, "Unexpected event on apdu reader gate\n");
381 		return 1;
382 	}
383 
384 exit:
385 	kfree_skb(skb);
386 	return r;
387 }
388 EXPORT_SYMBOL(st21nfca_apdu_reader_event_received);
389 
390 void st21nfca_se_init(struct nfc_hci_dev *hdev)
391 {
392 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
393 
394 	init_completion(&info->se_info.req_completion);
395 	/* initialize timers */
396 	init_timer(&info->se_info.bwi_timer);
397 	info->se_info.bwi_timer.data = (unsigned long)info;
398 	info->se_info.bwi_timer.function = st21nfca_se_wt_timeout;
399 	info->se_info.bwi_active = false;
400 
401 	init_timer(&info->se_info.se_active_timer);
402 	info->se_info.se_active_timer.data = (unsigned long)info;
403 	info->se_info.se_active_timer.function = st21nfca_se_activation_timeout;
404 	info->se_info.se_active = false;
405 
406 	info->se_info.count_pipes = 0;
407 	info->se_info.expected_pipes = 0;
408 
409 	info->se_info.xch_error = false;
410 
411 	info->se_info.wt_timeout =
412 			ST21NFCA_BWI_TO_TIMEOUT(ST21NFCA_ATR_DEFAULT_BWI);
413 }
414 EXPORT_SYMBOL(st21nfca_se_init);
415 
416 void st21nfca_se_deinit(struct nfc_hci_dev *hdev)
417 {
418 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
419 
420 	if (info->se_info.bwi_active)
421 		del_timer_sync(&info->se_info.bwi_timer);
422 	if (info->se_info.se_active)
423 		del_timer_sync(&info->se_info.se_active_timer);
424 
425 	info->se_info.bwi_active = false;
426 	info->se_info.se_active = false;
427 }
428 EXPORT_SYMBOL(st21nfca_se_deinit);
429