xref: /kernel/linux/linux-6.6/drivers/nfc/st21nfca/se.c (revision 62306a36)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
4 */
5
6#include <net/nfc/hci.h>
7
8#include "st21nfca.h"
9
10#define ST21NFCA_EVT_UICC_ACTIVATE		0x10
11#define ST21NFCA_EVT_UICC_DEACTIVATE		0x13
12#define ST21NFCA_EVT_SE_HARD_RESET		0x20
13#define ST21NFCA_EVT_SE_SOFT_RESET		0x11
14#define ST21NFCA_EVT_SE_END_OF_APDU_TRANSFER	0x21
15#define ST21NFCA_EVT_SE_ACTIVATE		0x22
16#define ST21NFCA_EVT_SE_DEACTIVATE		0x23
17
18#define ST21NFCA_EVT_TRANSMIT_DATA		0x10
19#define ST21NFCA_EVT_WTX_REQUEST		0x11
20
21#define ST21NFCA_EVT_CONNECTIVITY		0x10
22#define ST21NFCA_EVT_TRANSACTION		0x12
23
24#define ST21NFCA_SE_TO_HOT_PLUG			1000
25/* Connectivity pipe only */
26#define ST21NFCA_SE_COUNT_PIPE_UICC		0x01
27/* Connectivity + APDU Reader pipe */
28#define ST21NFCA_SE_COUNT_PIPE_EMBEDDED	0x02
29
30#define ST21NFCA_SE_MODE_OFF			0x00
31#define ST21NFCA_SE_MODE_ON				0x01
32
33#define ST21NFCA_PARAM_ATR				0x01
34#define ST21NFCA_ATR_DEFAULT_BWI		0x04
35
36/*
37 * WT = 2^BWI/10[s], convert into msecs and add a secure
38 * room by increasing by 2 this timeout
39 */
40#define ST21NFCA_BWI_TO_TIMEOUT(x)		((1 << x) * 200)
41#define ST21NFCA_ATR_GET_Y_FROM_TD(x)	(x >> 4)
42
43/* If TA is present bit 0 is set */
44#define ST21NFCA_ATR_TA_PRESENT(x) (x & 0x01)
45/* If TB is present bit 1 is set */
46#define ST21NFCA_ATR_TB_PRESENT(x) (x & 0x02)
47
48static u8 st21nfca_se_get_bwi(struct nfc_hci_dev *hdev)
49{
50	int i;
51	u8 td;
52	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
53
54	/* Bits 8 to 5 of the first TB for T=1 encode BWI from zero to nine */
55	for (i = 1; i < ST21NFCA_ESE_MAX_LENGTH; i++) {
56		td = ST21NFCA_ATR_GET_Y_FROM_TD(info->se_info.atr[i]);
57		if (ST21NFCA_ATR_TA_PRESENT(td))
58			i++;
59		if (ST21NFCA_ATR_TB_PRESENT(td)) {
60			i++;
61			return info->se_info.atr[i] >> 4;
62		}
63	}
64	return ST21NFCA_ATR_DEFAULT_BWI;
65}
66
67static void st21nfca_se_get_atr(struct nfc_hci_dev *hdev)
68{
69	int r;
70	struct sk_buff *skb;
71	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
72
73	r = nfc_hci_get_param(hdev, ST21NFCA_APDU_READER_GATE,
74			ST21NFCA_PARAM_ATR, &skb);
75	if (r < 0)
76		return;
77
78	if (skb->len <= ST21NFCA_ESE_MAX_LENGTH) {
79		memcpy(info->se_info.atr, skb->data, skb->len);
80		info->se_info.wt_timeout =
81			ST21NFCA_BWI_TO_TIMEOUT(st21nfca_se_get_bwi(hdev));
82	}
83	kfree_skb(skb);
84}
85
86static int st21nfca_hci_control_se(struct nfc_hci_dev *hdev, u32 se_idx,
87				u8 state)
88{
89	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
90	int r, i;
91	struct sk_buff *sk_host_list;
92	u8 se_event, host_id;
93
94	switch (se_idx) {
95	case NFC_HCI_UICC_HOST_ID:
96		se_event = (state == ST21NFCA_SE_MODE_ON ?
97					ST21NFCA_EVT_UICC_ACTIVATE :
98					ST21NFCA_EVT_UICC_DEACTIVATE);
99
100		info->se_info.count_pipes = 0;
101		info->se_info.expected_pipes = ST21NFCA_SE_COUNT_PIPE_UICC;
102		break;
103	case ST21NFCA_ESE_HOST_ID:
104		se_event = (state == ST21NFCA_SE_MODE_ON ?
105					ST21NFCA_EVT_SE_ACTIVATE :
106					ST21NFCA_EVT_SE_DEACTIVATE);
107
108		info->se_info.count_pipes = 0;
109		info->se_info.expected_pipes = ST21NFCA_SE_COUNT_PIPE_EMBEDDED;
110		break;
111	default:
112		return -EINVAL;
113	}
114
115	/*
116	 * Wait for an EVT_HOT_PLUG in order to
117	 * retrieve a relevant host list.
118	 */
119	reinit_completion(&info->se_info.req_completion);
120	r = nfc_hci_send_event(hdev, ST21NFCA_DEVICE_MGNT_GATE, se_event,
121			       NULL, 0);
122	if (r < 0)
123		return r;
124
125	mod_timer(&info->se_info.se_active_timer, jiffies +
126		msecs_to_jiffies(ST21NFCA_SE_TO_HOT_PLUG));
127	info->se_info.se_active = true;
128
129	/* Ignore return value and check in any case the host_list */
130	wait_for_completion_interruptible(&info->se_info.req_completion);
131
132	r = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,
133			NFC_HCI_ADMIN_HOST_LIST,
134			&sk_host_list);
135	if (r < 0)
136		return r;
137
138	for (i = 0; i < sk_host_list->len &&
139		sk_host_list->data[i] != se_idx; i++)
140		;
141	host_id = sk_host_list->data[i];
142	kfree_skb(sk_host_list);
143
144	if (state == ST21NFCA_SE_MODE_ON && host_id == se_idx)
145		return se_idx;
146	else if (state == ST21NFCA_SE_MODE_OFF && host_id != se_idx)
147		return se_idx;
148
149	return -1;
150}
151
152int st21nfca_hci_discover_se(struct nfc_hci_dev *hdev)
153{
154	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
155	int se_count = 0;
156
157	if (test_bit(ST21NFCA_FACTORY_MODE, &hdev->quirks))
158		return 0;
159
160	if (info->se_status->is_uicc_present) {
161		nfc_add_se(hdev->ndev, NFC_HCI_UICC_HOST_ID, NFC_SE_UICC);
162		se_count++;
163	}
164
165	if (info->se_status->is_ese_present) {
166		nfc_add_se(hdev->ndev, ST21NFCA_ESE_HOST_ID, NFC_SE_EMBEDDED);
167		se_count++;
168	}
169
170	return !se_count;
171}
172EXPORT_SYMBOL(st21nfca_hci_discover_se);
173
174int st21nfca_hci_enable_se(struct nfc_hci_dev *hdev, u32 se_idx)
175{
176	int r;
177
178	/*
179	 * According to upper layer, se_idx == NFC_SE_UICC when
180	 * info->se_status->is_uicc_enable is true should never happen.
181	 * Same for eSE.
182	 */
183	r = st21nfca_hci_control_se(hdev, se_idx, ST21NFCA_SE_MODE_ON);
184	if (r == ST21NFCA_ESE_HOST_ID) {
185		st21nfca_se_get_atr(hdev);
186		r = nfc_hci_send_event(hdev, ST21NFCA_APDU_READER_GATE,
187				ST21NFCA_EVT_SE_SOFT_RESET, NULL, 0);
188		if (r < 0)
189			return r;
190	} else if (r < 0) {
191		/*
192		 * The activation tentative failed, the secure element
193		 * is not connected. Remove from the list.
194		 */
195		nfc_remove_se(hdev->ndev, se_idx);
196		return r;
197	}
198
199	return 0;
200}
201EXPORT_SYMBOL(st21nfca_hci_enable_se);
202
203int st21nfca_hci_disable_se(struct nfc_hci_dev *hdev, u32 se_idx)
204{
205	int r;
206
207	/*
208	 * According to upper layer, se_idx == NFC_SE_UICC when
209	 * info->se_status->is_uicc_enable is true should never happen
210	 * Same for eSE.
211	 */
212	r = st21nfca_hci_control_se(hdev, se_idx, ST21NFCA_SE_MODE_OFF);
213	if (r < 0)
214		return r;
215
216	return 0;
217}
218EXPORT_SYMBOL(st21nfca_hci_disable_se);
219
220int st21nfca_hci_se_io(struct nfc_hci_dev *hdev, u32 se_idx,
221			u8 *apdu, size_t apdu_length,
222			se_io_cb_t cb, void *cb_context)
223{
224	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
225
226	pr_debug("se_io %x\n", se_idx);
227
228	switch (se_idx) {
229	case ST21NFCA_ESE_HOST_ID:
230		info->se_info.cb = cb;
231		info->se_info.cb_context = cb_context;
232		mod_timer(&info->se_info.bwi_timer, jiffies +
233			  msecs_to_jiffies(info->se_info.wt_timeout));
234		info->se_info.bwi_active = true;
235		return nfc_hci_send_event(hdev, ST21NFCA_APDU_READER_GATE,
236					ST21NFCA_EVT_TRANSMIT_DATA,
237					apdu, apdu_length);
238	default:
239		/* Need to free cb_context here as at the moment we can't
240		 * clearly indicate to the caller if the callback function
241		 * would be called (and free it) or not. In both cases a
242		 * negative value may be returned to the caller.
243		 */
244		kfree(cb_context);
245		return -ENODEV;
246	}
247}
248EXPORT_SYMBOL(st21nfca_hci_se_io);
249
250static void st21nfca_se_wt_work(struct work_struct *work)
251{
252	/*
253	 * No answer from the secure element
254	 * within the defined timeout.
255	 * Let's send a reset request as recovery procedure.
256	 * According to the situation, we first try to send a software reset
257	 * to the secure element. If the next command is still not
258	 * answering in time, we send to the CLF a secure element hardware
259	 * reset request.
260	 */
261	/* hardware reset managed through VCC_UICC_OUT power supply */
262	u8 param = 0x01;
263	struct st21nfca_hci_info *info = container_of(work,
264						struct st21nfca_hci_info,
265						se_info.timeout_work);
266
267	info->se_info.bwi_active = false;
268
269	if (!info->se_info.xch_error) {
270		info->se_info.xch_error = true;
271		nfc_hci_send_event(info->hdev, ST21NFCA_APDU_READER_GATE,
272				ST21NFCA_EVT_SE_SOFT_RESET, NULL, 0);
273	} else {
274		info->se_info.xch_error = false;
275		nfc_hci_send_event(info->hdev, ST21NFCA_DEVICE_MGNT_GATE,
276				ST21NFCA_EVT_SE_HARD_RESET, &param, 1);
277	}
278	info->se_info.cb(info->se_info.cb_context, NULL, 0, -ETIME);
279}
280
281static void st21nfca_se_wt_timeout(struct timer_list *t)
282{
283	struct st21nfca_hci_info *info = from_timer(info, t, se_info.bwi_timer);
284
285	schedule_work(&info->se_info.timeout_work);
286}
287
288static void st21nfca_se_activation_timeout(struct timer_list *t)
289{
290	struct st21nfca_hci_info *info = from_timer(info, t,
291						    se_info.se_active_timer);
292
293	info->se_info.se_active = false;
294
295	complete(&info->se_info.req_completion);
296}
297
298/*
299 * Returns:
300 * <= 0: driver handled the event, skb consumed
301 *    1: driver does not handle the event, please do standard processing
302 */
303int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
304				u8 event, struct sk_buff *skb)
305{
306	int r = 0;
307	struct device *dev = &hdev->ndev->dev;
308	struct nfc_evt_transaction *transaction;
309	u32 aid_len;
310	u8 params_len;
311
312	pr_debug("connectivity gate event: %x\n", event);
313
314	switch (event) {
315	case ST21NFCA_EVT_CONNECTIVITY:
316		r = nfc_se_connectivity(hdev->ndev, host);
317	break;
318	case ST21NFCA_EVT_TRANSACTION:
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		 * The key differences are aid storage length is variably sized
326		 * in the packet, but fixed in nfc_evt_transaction, and that the aid_len
327		 * is u8 in the packet, but u32 in the structure, and the tags in
328		 * the packet are not included in nfc_evt_transaction.
329		 *
330		 * size in bytes: 1          1       5-16 1             1           0-255
331		 * offset:        0          1       2    aid_len + 2   aid_len + 3 aid_len + 4
332		 * member name:   aid_tag(M) aid_len aid  params_tag(M) params_len  params
333		 * example:       0x81       5-16    X    0x82 0-255    X
334		 */
335		if (skb->len < 2 || skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG)
336			return -EPROTO;
337
338		aid_len = skb->data[1];
339
340		if (skb->len < aid_len + 4 || aid_len > sizeof(transaction->aid))
341			return -EPROTO;
342
343		params_len = skb->data[aid_len + 3];
344
345		/* Verify PARAMETERS tag is (82), and final check that there is enough
346		 * space in the packet to read everything.
347		 */
348		if ((skb->data[aid_len + 2] != NFC_EVT_TRANSACTION_PARAMS_TAG) ||
349		    (skb->len < aid_len + 4 + params_len))
350			return -EPROTO;
351
352		transaction = devm_kzalloc(dev, sizeof(*transaction) + params_len, GFP_KERNEL);
353		if (!transaction)
354			return -ENOMEM;
355
356		transaction->aid_len = aid_len;
357		transaction->params_len = params_len;
358
359		memcpy(transaction->aid, &skb->data[2], aid_len);
360		memcpy(transaction->params, &skb->data[aid_len + 4], params_len);
361
362		r = nfc_se_transaction(hdev->ndev, host, transaction);
363	break;
364	default:
365		nfc_err(&hdev->ndev->dev, "Unexpected event on connectivity gate\n");
366		return 1;
367	}
368	kfree_skb(skb);
369	return r;
370}
371EXPORT_SYMBOL(st21nfca_connectivity_event_received);
372
373int st21nfca_apdu_reader_event_received(struct nfc_hci_dev *hdev,
374					u8 event, struct sk_buff *skb)
375{
376	int r = 0;
377	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
378
379	pr_debug("apdu reader gate event: %x\n", event);
380
381	switch (event) {
382	case ST21NFCA_EVT_TRANSMIT_DATA:
383		del_timer_sync(&info->se_info.bwi_timer);
384		cancel_work_sync(&info->se_info.timeout_work);
385		info->se_info.bwi_active = false;
386		r = nfc_hci_send_event(hdev, ST21NFCA_DEVICE_MGNT_GATE,
387				ST21NFCA_EVT_SE_END_OF_APDU_TRANSFER, NULL, 0);
388		if (r < 0)
389			goto exit;
390
391		info->se_info.cb(info->se_info.cb_context,
392			skb->data, skb->len, 0);
393		break;
394	case ST21NFCA_EVT_WTX_REQUEST:
395		mod_timer(&info->se_info.bwi_timer, jiffies +
396				msecs_to_jiffies(info->se_info.wt_timeout));
397		break;
398	default:
399		nfc_err(&hdev->ndev->dev, "Unexpected event on apdu reader gate\n");
400		return 1;
401	}
402
403exit:
404	kfree_skb(skb);
405	return r;
406}
407EXPORT_SYMBOL(st21nfca_apdu_reader_event_received);
408
409void st21nfca_se_init(struct nfc_hci_dev *hdev)
410{
411	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
412
413	init_completion(&info->se_info.req_completion);
414	INIT_WORK(&info->se_info.timeout_work, st21nfca_se_wt_work);
415	/* initialize timers */
416	timer_setup(&info->se_info.bwi_timer, st21nfca_se_wt_timeout, 0);
417	info->se_info.bwi_active = false;
418
419	timer_setup(&info->se_info.se_active_timer,
420		    st21nfca_se_activation_timeout, 0);
421	info->se_info.se_active = false;
422
423	info->se_info.count_pipes = 0;
424	info->se_info.expected_pipes = 0;
425
426	info->se_info.xch_error = false;
427
428	info->se_info.wt_timeout =
429			ST21NFCA_BWI_TO_TIMEOUT(ST21NFCA_ATR_DEFAULT_BWI);
430}
431EXPORT_SYMBOL(st21nfca_se_init);
432
433void st21nfca_se_deinit(struct nfc_hci_dev *hdev)
434{
435	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
436
437	if (info->se_info.bwi_active)
438		del_timer_sync(&info->se_info.bwi_timer);
439	if (info->se_info.se_active)
440		del_timer_sync(&info->se_info.se_active_timer);
441
442	cancel_work_sync(&info->se_info.timeout_work);
443	info->se_info.bwi_active = false;
444	info->se_info.se_active = false;
445}
446EXPORT_SYMBOL(st21nfca_se_deinit);
447