xref: /linux/net/nfc/hci/command.c (revision 2da68a77) 
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2012  Intel Corporation. All rights reserved.
4  */
5 
6 #define pr_fmt(fmt) "hci: %s: " fmt, __func__
7 
8 #include <linux/init.h>
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/module.h>
12 
13 #include <net/nfc/hci.h>
14 
15 #include "hci.h"
16 
17 #define MAX_FWI 4949
18 
19 static int nfc_hci_execute_cmd_async(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
20 			       const u8 *param, size_t param_len,
21 			       data_exchange_cb_t cb, void *cb_context)
22 {
23 	pr_debug("exec cmd async through pipe=%d, cmd=%d, plen=%zd\n", pipe,
24 		 cmd, param_len);
25 
26 	/* TODO: Define hci cmd execution delay. Should it be the same
27 	 * for all commands?
28 	 */
29 	return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_COMMAND, cmd,
30 				      param, param_len, cb, cb_context, MAX_FWI);
31 }
32 
33 /*
34  * HCI command execution completion callback.
35  * err will be a standard linux error (may be converted from HCI response)
36  * skb contains the response data and must be disposed, or may be NULL if
37  * an error occurred
38  */
39 static void nfc_hci_execute_cb(void *context, struct sk_buff *skb, int err)
40 {
41 	struct hcp_exec_waiter *hcp_ew = (struct hcp_exec_waiter *)context;
42 
43 	pr_debug("HCI Cmd completed with result=%d\n", err);
44 
45 	hcp_ew->exec_result = err;
46 	if (hcp_ew->exec_result == 0)
47 		hcp_ew->result_skb = skb;
48 	else
49 		kfree_skb(skb);
50 	hcp_ew->exec_complete = true;
51 
52 	wake_up(hcp_ew->wq);
53 }
54 
55 static int nfc_hci_execute_cmd(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
56 			       const u8 *param, size_t param_len,
57 			       struct sk_buff **skb)
58 {
59 	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(ew_wq);
60 	struct hcp_exec_waiter hcp_ew;
61 	hcp_ew.wq = &ew_wq;
62 	hcp_ew.exec_complete = false;
63 	hcp_ew.result_skb = NULL;
64 
65 	pr_debug("exec cmd sync through pipe=%d, cmd=%d, plen=%zd\n", pipe,
66 		 cmd, param_len);
67 
68 	/* TODO: Define hci cmd execution delay. Should it be the same
69 	 * for all commands?
70 	 */
71 	hcp_ew.exec_result = nfc_hci_hcp_message_tx(hdev, pipe,
72 						    NFC_HCI_HCP_COMMAND, cmd,
73 						    param, param_len,
74 						    nfc_hci_execute_cb, &hcp_ew,
75 						    MAX_FWI);
76 	if (hcp_ew.exec_result < 0)
77 		return hcp_ew.exec_result;
78 
79 	wait_event(ew_wq, hcp_ew.exec_complete == true);
80 
81 	if (hcp_ew.exec_result == 0) {
82 		if (skb)
83 			*skb = hcp_ew.result_skb;
84 		else
85 			kfree_skb(hcp_ew.result_skb);
86 	}
87 
88 	return hcp_ew.exec_result;
89 }
90 
91 int nfc_hci_send_event(struct nfc_hci_dev *hdev, u8 gate, u8 event,
92 		       const u8 *param, size_t param_len)
93 {
94 	u8 pipe;
95 
96 	pr_debug("%d to gate %d\n", event, gate);
97 
98 	pipe = hdev->gate2pipe[gate];
99 	if (pipe == NFC_HCI_INVALID_PIPE)
100 		return -EADDRNOTAVAIL;
101 
102 	return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_EVENT, event,
103 				      param, param_len, NULL, NULL, 0);
104 }
105 EXPORT_SYMBOL(nfc_hci_send_event);
106 
107 /*
108  * Execute an hci command sent to gate.
109  * skb will contain response data if success. skb can be NULL if you are not
110  * interested by the response.
111  */
112 int nfc_hci_send_cmd(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
113 		     const u8 *param, size_t param_len, struct sk_buff **skb)
114 {
115 	u8 pipe;
116 
117 	pipe = hdev->gate2pipe[gate];
118 	if (pipe == NFC_HCI_INVALID_PIPE)
119 		return -EADDRNOTAVAIL;
120 
121 	return nfc_hci_execute_cmd(hdev, pipe, cmd, param, param_len, skb);
122 }
123 EXPORT_SYMBOL(nfc_hci_send_cmd);
124 
125 int nfc_hci_send_cmd_async(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
126 			   const u8 *param, size_t param_len,
127 			   data_exchange_cb_t cb, void *cb_context)
128 {
129 	u8 pipe;
130 
131 	pipe = hdev->gate2pipe[gate];
132 	if (pipe == NFC_HCI_INVALID_PIPE)
133 		return -EADDRNOTAVAIL;
134 
135 	return nfc_hci_execute_cmd_async(hdev, pipe, cmd, param, param_len,
136 					 cb, cb_context);
137 }
138 EXPORT_SYMBOL(nfc_hci_send_cmd_async);
139 
140 int nfc_hci_set_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
141 		      const u8 *param, size_t param_len)
142 {
143 	int r;
144 	u8 *tmp;
145 
146 	/* TODO ELa: reg idx must be inserted before param, but we don't want
147 	 * to ask the caller to do it to keep a simpler API.
148 	 * For now, just create a new temporary param buffer. This is far from
149 	 * optimal though, and the plan is to modify APIs to pass idx down to
150 	 * nfc_hci_hcp_message_tx where the frame is actually built, thereby
151 	 * eliminating the need for the temp allocation-copy here.
152 	 */
153 
154 	pr_debug("idx=%d to gate %d\n", idx, gate);
155 
156 	tmp = kmalloc(1 + param_len, GFP_KERNEL);
157 	if (tmp == NULL)
158 		return -ENOMEM;
159 
160 	*tmp = idx;
161 	memcpy(tmp + 1, param, param_len);
162 
163 	r = nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_SET_PARAMETER,
164 			     tmp, param_len + 1, NULL);
165 
166 	kfree(tmp);
167 
168 	return r;
169 }
170 EXPORT_SYMBOL(nfc_hci_set_param);
171 
172 int nfc_hci_get_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
173 		      struct sk_buff **skb)
174 {
175 	pr_debug("gate=%d regidx=%d\n", gate, idx);
176 
177 	return nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_GET_PARAMETER,
178 				&idx, 1, skb);
179 }
180 EXPORT_SYMBOL(nfc_hci_get_param);
181 
182 static int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)
183 {
184 	struct sk_buff *skb;
185 	int r;
186 
187 	pr_debug("pipe=%d\n", pipe);
188 
189 	r = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,
190 				NULL, 0, &skb);
191 	if (r == 0) {
192 		/* dest host other than host controller will send
193 		 * number of pipes already open on this gate before
194 		 * execution. The number can be found in skb->data[0]
195 		 */
196 		kfree_skb(skb);
197 	}
198 
199 	return r;
200 }
201 
202 static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)
203 {
204 	return nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,
205 				   NULL, 0, NULL);
206 }
207 
208 static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,
209 			      u8 dest_gate, int *result)
210 {
211 	struct sk_buff *skb;
212 	struct hci_create_pipe_params params;
213 	struct hci_create_pipe_resp *resp;
214 	u8 pipe;
215 
216 	pr_debug("gate=%d\n", dest_gate);
217 
218 	params.src_gate = NFC_HCI_ADMIN_GATE;
219 	params.dest_host = dest_host;
220 	params.dest_gate = dest_gate;
221 
222 	*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
223 				      NFC_HCI_ADM_CREATE_PIPE,
224 				      (u8 *) &params, sizeof(params), &skb);
225 	if (*result < 0)
226 		return NFC_HCI_INVALID_PIPE;
227 
228 	resp = (struct hci_create_pipe_resp *)skb->data;
229 	pipe = resp->pipe;
230 	kfree_skb(skb);
231 
232 	pr_debug("pipe created=%d\n", pipe);
233 
234 	return pipe;
235 }
236 
237 static int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)
238 {
239 	return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
240 				   NFC_HCI_ADM_DELETE_PIPE, &pipe, 1, NULL);
241 }
242 
243 static int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)
244 {
245 	u8 param[2];
246 	size_t param_len = 2;
247 
248 	/* TODO: Find out what the identity reference data is
249 	 * and fill param with it. HCI spec 6.1.3.5 */
250 
251 	if (test_bit(NFC_HCI_QUIRK_SHORT_CLEAR, &hdev->quirks))
252 		param_len = 0;
253 
254 	return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
255 				   NFC_HCI_ADM_CLEAR_ALL_PIPE, param, param_len,
256 				   NULL);
257 }
258 
259 int nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)
260 {
261 	int r;
262 	u8 pipe = hdev->gate2pipe[gate];
263 
264 	if (pipe == NFC_HCI_INVALID_PIPE)
265 		return -EADDRNOTAVAIL;
266 
267 	r = nfc_hci_close_pipe(hdev, pipe);
268 	if (r < 0)
269 		return r;
270 
271 	if (pipe != NFC_HCI_LINK_MGMT_PIPE && pipe != NFC_HCI_ADMIN_PIPE) {
272 		r = nfc_hci_delete_pipe(hdev, pipe);
273 		if (r < 0)
274 			return r;
275 	}
276 
277 	hdev->gate2pipe[gate] = NFC_HCI_INVALID_PIPE;
278 
279 	return 0;
280 }
281 EXPORT_SYMBOL(nfc_hci_disconnect_gate);
282 
283 int nfc_hci_disconnect_all_gates(struct nfc_hci_dev *hdev)
284 {
285 	int r;
286 
287 	r = nfc_hci_clear_all_pipes(hdev);
288 	if (r < 0)
289 		return r;
290 
291 	nfc_hci_reset_pipes(hdev);
292 
293 	return 0;
294 }
295 EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);
296 
297 int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,
298 			 u8 pipe)
299 {
300 	bool pipe_created = false;
301 	int r;
302 
303 	if (pipe == NFC_HCI_DO_NOT_CREATE_PIPE)
304 		return 0;
305 
306 	if (hdev->gate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)
307 		return -EADDRINUSE;
308 
309 	if (pipe != NFC_HCI_INVALID_PIPE)
310 		goto open_pipe;
311 
312 	switch (dest_gate) {
313 	case NFC_HCI_LINK_MGMT_GATE:
314 		pipe = NFC_HCI_LINK_MGMT_PIPE;
315 		break;
316 	case NFC_HCI_ADMIN_GATE:
317 		pipe = NFC_HCI_ADMIN_PIPE;
318 		break;
319 	default:
320 		pipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, &r);
321 		if (pipe == NFC_HCI_INVALID_PIPE)
322 			return r;
323 		pipe_created = true;
324 		break;
325 	}
326 
327 open_pipe:
328 	r = nfc_hci_open_pipe(hdev, pipe);
329 	if (r < 0) {
330 		if (pipe_created)
331 			if (nfc_hci_delete_pipe(hdev, pipe) < 0) {
332 				/* TODO: Cannot clean by deleting pipe...
333 				 * -> inconsistent state */
334 			}
335 		return r;
336 	}
337 
338 	hdev->pipes[pipe].gate = dest_gate;
339 	hdev->pipes[pipe].dest_host = dest_host;
340 	hdev->gate2pipe[dest_gate] = pipe;
341 
342 	return 0;
343 }
344 EXPORT_SYMBOL(nfc_hci_connect_gate);
345