xref: /openbmc/linux/drivers/nfc/st21nfca/se.c (revision 82e6fdd6)
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_SE_TO_HOT_PLUG			1000
36 /* Connectivity pipe only */
37 #define ST21NFCA_SE_COUNT_PIPE_UICC		0x01
38 /* Connectivity + APDU Reader pipe */
39 #define ST21NFCA_SE_COUNT_PIPE_EMBEDDED	0x02
40 
41 #define ST21NFCA_SE_MODE_OFF			0x00
42 #define ST21NFCA_SE_MODE_ON				0x01
43 
44 #define ST21NFCA_PARAM_ATR				0x01
45 #define ST21NFCA_ATR_DEFAULT_BWI		0x04
46 
47 /*
48  * WT = 2^BWI/10[s], convert into msecs and add a secure
49  * room by increasing by 2 this timeout
50  */
51 #define ST21NFCA_BWI_TO_TIMEOUT(x)		((1 << x) * 200)
52 #define ST21NFCA_ATR_GET_Y_FROM_TD(x)	(x >> 4)
53 
54 /* If TA is present bit 0 is set */
55 #define ST21NFCA_ATR_TA_PRESENT(x) (x & 0x01)
56 /* If TB is present bit 1 is set */
57 #define ST21NFCA_ATR_TB_PRESENT(x) (x & 0x02)
58 
59 static u8 st21nfca_se_get_bwi(struct nfc_hci_dev *hdev)
60 {
61 	int i;
62 	u8 td;
63 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
64 
65 	/* Bits 8 to 5 of the first TB for T=1 encode BWI from zero to nine */
66 	for (i = 1; i < ST21NFCA_ESE_MAX_LENGTH; i++) {
67 		td = ST21NFCA_ATR_GET_Y_FROM_TD(info->se_info.atr[i]);
68 		if (ST21NFCA_ATR_TA_PRESENT(td))
69 			i++;
70 		if (ST21NFCA_ATR_TB_PRESENT(td)) {
71 			i++;
72 			return info->se_info.atr[i] >> 4;
73 		}
74 	}
75 	return ST21NFCA_ATR_DEFAULT_BWI;
76 }
77 
78 static void st21nfca_se_get_atr(struct nfc_hci_dev *hdev)
79 {
80 	int r;
81 	struct sk_buff *skb;
82 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
83 
84 	r = nfc_hci_get_param(hdev, ST21NFCA_APDU_READER_GATE,
85 			ST21NFCA_PARAM_ATR, &skb);
86 	if (r < 0)
87 		return;
88 
89 	if (skb->len <= ST21NFCA_ESE_MAX_LENGTH) {
90 		memcpy(info->se_info.atr, skb->data, skb->len);
91 		info->se_info.wt_timeout =
92 			ST21NFCA_BWI_TO_TIMEOUT(st21nfca_se_get_bwi(hdev));
93 	}
94 	kfree_skb(skb);
95 }
96 
97 static int st21nfca_hci_control_se(struct nfc_hci_dev *hdev, u32 se_idx,
98 				u8 state)
99 {
100 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
101 	int r, i;
102 	struct sk_buff *sk_host_list;
103 	u8 se_event, host_id;
104 
105 	switch (se_idx) {
106 	case NFC_HCI_UICC_HOST_ID:
107 		se_event = (state == ST21NFCA_SE_MODE_ON ?
108 					ST21NFCA_EVT_UICC_ACTIVATE :
109 					ST21NFCA_EVT_UICC_DEACTIVATE);
110 
111 		info->se_info.count_pipes = 0;
112 		info->se_info.expected_pipes = ST21NFCA_SE_COUNT_PIPE_UICC;
113 		break;
114 	case ST21NFCA_ESE_HOST_ID:
115 		se_event = (state == ST21NFCA_SE_MODE_ON ?
116 					ST21NFCA_EVT_SE_ACTIVATE :
117 					ST21NFCA_EVT_SE_DEACTIVATE);
118 
119 		info->se_info.count_pipes = 0;
120 		info->se_info.expected_pipes = ST21NFCA_SE_COUNT_PIPE_EMBEDDED;
121 		break;
122 	default:
123 		return -EINVAL;
124 	}
125 
126 	/*
127 	 * Wait for an EVT_HOT_PLUG in order to
128 	 * retrieve a relevant host list.
129 	 */
130 	reinit_completion(&info->se_info.req_completion);
131 	r = nfc_hci_send_event(hdev, ST21NFCA_DEVICE_MGNT_GATE, se_event,
132 			       NULL, 0);
133 	if (r < 0)
134 		return r;
135 
136 	mod_timer(&info->se_info.se_active_timer, jiffies +
137 		msecs_to_jiffies(ST21NFCA_SE_TO_HOT_PLUG));
138 	info->se_info.se_active = true;
139 
140 	/* Ignore return value and check in any case the host_list */
141 	wait_for_completion_interruptible(&info->se_info.req_completion);
142 
143 	r = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,
144 			NFC_HCI_ADMIN_HOST_LIST,
145 			&sk_host_list);
146 	if (r < 0)
147 		return r;
148 
149 	for (i = 0; i < sk_host_list->len &&
150 		sk_host_list->data[i] != se_idx; i++)
151 		;
152 	host_id = sk_host_list->data[i];
153 	kfree_skb(sk_host_list);
154 
155 	if (state == ST21NFCA_SE_MODE_ON && host_id == se_idx)
156 		return se_idx;
157 	else if (state == ST21NFCA_SE_MODE_OFF && host_id != se_idx)
158 		return se_idx;
159 
160 	return -1;
161 }
162 
163 int st21nfca_hci_discover_se(struct nfc_hci_dev *hdev)
164 {
165 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
166 	int se_count = 0;
167 
168 	if (test_bit(ST21NFCA_FACTORY_MODE, &hdev->quirks))
169 		return 0;
170 
171 	if (info->se_status->is_uicc_present) {
172 		nfc_add_se(hdev->ndev, NFC_HCI_UICC_HOST_ID, NFC_SE_UICC);
173 		se_count++;
174 	}
175 
176 	if (info->se_status->is_ese_present) {
177 		nfc_add_se(hdev->ndev, ST21NFCA_ESE_HOST_ID, NFC_SE_EMBEDDED);
178 		se_count++;
179 	}
180 
181 	return !se_count;
182 }
183 EXPORT_SYMBOL(st21nfca_hci_discover_se);
184 
185 int st21nfca_hci_enable_se(struct nfc_hci_dev *hdev, u32 se_idx)
186 {
187 	int r;
188 
189 	/*
190 	 * According to upper layer, se_idx == NFC_SE_UICC when
191 	 * info->se_status->is_uicc_enable is true should never happen.
192 	 * Same for eSE.
193 	 */
194 	r = st21nfca_hci_control_se(hdev, se_idx, ST21NFCA_SE_MODE_ON);
195 	if (r == ST21NFCA_ESE_HOST_ID) {
196 		st21nfca_se_get_atr(hdev);
197 		r = nfc_hci_send_event(hdev, ST21NFCA_APDU_READER_GATE,
198 				ST21NFCA_EVT_SE_SOFT_RESET, NULL, 0);
199 		if (r < 0)
200 			return r;
201 	} else if (r < 0) {
202 		/*
203 		 * The activation tentative failed, the secure element
204 		 * is not connected. Remove from the list.
205 		 */
206 		nfc_remove_se(hdev->ndev, se_idx);
207 		return r;
208 	}
209 
210 	return 0;
211 }
212 EXPORT_SYMBOL(st21nfca_hci_enable_se);
213 
214 int st21nfca_hci_disable_se(struct nfc_hci_dev *hdev, u32 se_idx)
215 {
216 	int r;
217 
218 	/*
219 	 * According to upper layer, se_idx == NFC_SE_UICC when
220 	 * info->se_status->is_uicc_enable is true should never happen
221 	 * Same for eSE.
222 	 */
223 	r = st21nfca_hci_control_se(hdev, se_idx, ST21NFCA_SE_MODE_OFF);
224 	if (r < 0)
225 		return r;
226 
227 	return 0;
228 }
229 EXPORT_SYMBOL(st21nfca_hci_disable_se);
230 
231 int st21nfca_hci_se_io(struct nfc_hci_dev *hdev, u32 se_idx,
232 			u8 *apdu, size_t apdu_length,
233 			se_io_cb_t cb, void *cb_context)
234 {
235 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
236 
237 	pr_debug("se_io %x\n", se_idx);
238 
239 	switch (se_idx) {
240 	case ST21NFCA_ESE_HOST_ID:
241 		info->se_info.cb = cb;
242 		info->se_info.cb_context = cb_context;
243 		mod_timer(&info->se_info.bwi_timer, jiffies +
244 			  msecs_to_jiffies(info->se_info.wt_timeout));
245 		info->se_info.bwi_active = true;
246 		return nfc_hci_send_event(hdev, ST21NFCA_APDU_READER_GATE,
247 					ST21NFCA_EVT_TRANSMIT_DATA,
248 					apdu, apdu_length);
249 	default:
250 		return -ENODEV;
251 	}
252 }
253 EXPORT_SYMBOL(st21nfca_hci_se_io);
254 
255 static void st21nfca_se_wt_timeout(struct timer_list *t)
256 {
257 	/*
258 	 * No answer from the secure element
259 	 * within the defined timeout.
260 	 * Let's send a reset request as recovery procedure.
261 	 * According to the situation, we first try to send a software reset
262 	 * to the secure element. If the next command is still not
263 	 * answering in time, we send to the CLF a secure element hardware
264 	 * reset request.
265 	 */
266 	/* hardware reset managed through VCC_UICC_OUT power supply */
267 	u8 param = 0x01;
268 	struct st21nfca_hci_info *info = from_timer(info, t,
269 						    se_info.bwi_timer);
270 
271 	pr_debug("\n");
272 
273 	info->se_info.bwi_active = false;
274 
275 	if (!info->se_info.xch_error) {
276 		info->se_info.xch_error = true;
277 		nfc_hci_send_event(info->hdev, ST21NFCA_APDU_READER_GATE,
278 				ST21NFCA_EVT_SE_SOFT_RESET, NULL, 0);
279 	} else {
280 		info->se_info.xch_error = false;
281 		nfc_hci_send_event(info->hdev, ST21NFCA_DEVICE_MGNT_GATE,
282 				ST21NFCA_EVT_SE_HARD_RESET, &param, 1);
283 	}
284 	info->se_info.cb(info->se_info.cb_context, NULL, 0, -ETIME);
285 }
286 
287 static void st21nfca_se_activation_timeout(struct timer_list *t)
288 {
289 	struct st21nfca_hci_info *info = from_timer(info, t,
290 						    se_info.se_active_timer);
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 		r = nfc_se_connectivity(hdev->ndev, host);
316 	break;
317 	case ST21NFCA_EVT_TRANSACTION:
318 		/*
319 		 * According to specification etsi 102 622
320 		 * 11.2.2.4 EVT_TRANSACTION Table 52
321 		 * Description	Tag	Length
322 		 * AID		81	5 to 16
323 		 * PARAMETERS	82	0 to 255
324 		 */
325 		if (skb->len < NFC_MIN_AID_LENGTH + 2 &&
326 		    skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG)
327 			return -EPROTO;
328 
329 		transaction = (struct nfc_evt_transaction *)devm_kzalloc(dev,
330 						   skb->len - 2, GFP_KERNEL);
331 
332 		transaction->aid_len = skb->data[1];
333 		memcpy(transaction->aid, &skb->data[2],
334 		       transaction->aid_len);
335 
336 		/* Check next byte is PARAMETERS tag (82) */
337 		if (skb->data[transaction->aid_len + 2] !=
338 		    NFC_EVT_TRANSACTION_PARAMS_TAG)
339 			return -EPROTO;
340 
341 		transaction->params_len = skb->data[transaction->aid_len + 3];
342 		memcpy(transaction->params, skb->data +
343 		       transaction->aid_len + 4, transaction->params_len);
344 
345 		r = nfc_se_transaction(hdev->ndev, host, transaction);
346 	break;
347 	default:
348 		nfc_err(&hdev->ndev->dev, "Unexpected event on connectivity gate\n");
349 		return 1;
350 	}
351 	kfree_skb(skb);
352 	return r;
353 }
354 EXPORT_SYMBOL(st21nfca_connectivity_event_received);
355 
356 int st21nfca_apdu_reader_event_received(struct nfc_hci_dev *hdev,
357 					u8 event, struct sk_buff *skb)
358 {
359 	int r = 0;
360 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
361 
362 	pr_debug("apdu reader gate event: %x\n", event);
363 
364 	switch (event) {
365 	case ST21NFCA_EVT_TRANSMIT_DATA:
366 		del_timer_sync(&info->se_info.bwi_timer);
367 		info->se_info.bwi_active = false;
368 		r = nfc_hci_send_event(hdev, ST21NFCA_DEVICE_MGNT_GATE,
369 				ST21NFCA_EVT_SE_END_OF_APDU_TRANSFER, NULL, 0);
370 		if (r < 0)
371 			goto exit;
372 
373 		info->se_info.cb(info->se_info.cb_context,
374 			skb->data, skb->len, 0);
375 		break;
376 	case ST21NFCA_EVT_WTX_REQUEST:
377 		mod_timer(&info->se_info.bwi_timer, jiffies +
378 				msecs_to_jiffies(info->se_info.wt_timeout));
379 		break;
380 	default:
381 		nfc_err(&hdev->ndev->dev, "Unexpected event on apdu reader gate\n");
382 		return 1;
383 	}
384 
385 exit:
386 	kfree_skb(skb);
387 	return r;
388 }
389 EXPORT_SYMBOL(st21nfca_apdu_reader_event_received);
390 
391 void st21nfca_se_init(struct nfc_hci_dev *hdev)
392 {
393 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
394 
395 	init_completion(&info->se_info.req_completion);
396 	/* initialize timers */
397 	timer_setup(&info->se_info.bwi_timer, st21nfca_se_wt_timeout, 0);
398 	info->se_info.bwi_active = false;
399 
400 	timer_setup(&info->se_info.se_active_timer,
401 		    st21nfca_se_activation_timeout, 0);
402 	info->se_info.se_active = false;
403 
404 	info->se_info.count_pipes = 0;
405 	info->se_info.expected_pipes = 0;
406 
407 	info->se_info.xch_error = false;
408 
409 	info->se_info.wt_timeout =
410 			ST21NFCA_BWI_TO_TIMEOUT(ST21NFCA_ATR_DEFAULT_BWI);
411 }
412 EXPORT_SYMBOL(st21nfca_se_init);
413 
414 void st21nfca_se_deinit(struct nfc_hci_dev *hdev)
415 {
416 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
417 
418 	if (info->se_info.bwi_active)
419 		del_timer_sync(&info->se_info.bwi_timer);
420 	if (info->se_info.se_active)
421 		del_timer_sync(&info->se_info.se_active_timer);
422 
423 	info->se_info.bwi_active = false;
424 	info->se_info.se_active = false;
425 }
426 EXPORT_SYMBOL(st21nfca_se_deinit);
427