xref: /linux/net/nfc/hci/command.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
1 /*
2  * Copyright (C) 2012  Intel Corporation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the
16  * Free Software Foundation, Inc.,
17  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18  */
19 
20 #define pr_fmt(fmt) "hci: %s: " fmt, __func__
21 
22 #include <linux/init.h>
23 #include <linux/kernel.h>
24 #include <linux/sched.h>
25 #include <linux/module.h>
26 
27 #include <net/nfc/hci.h>
28 
29 #include "hci.h"
30 
31 static int nfc_hci_result_to_errno(u8 result)
32 {
33 	switch (result) {
34 	case NFC_HCI_ANY_OK:
35 		return 0;
36 	case NFC_HCI_ANY_E_TIMEOUT:
37 		return -ETIMEDOUT;
38 	default:
39 		return -1;
40 	}
41 }
42 
43 static void nfc_hci_execute_cb(struct nfc_hci_dev *hdev, u8 result,
44 			       struct sk_buff *skb, void *cb_data)
45 {
46 	struct hcp_exec_waiter *hcp_ew = (struct hcp_exec_waiter *)cb_data;
47 
48 	pr_debug("HCI Cmd completed with HCI result=%d\n", result);
49 
50 	hcp_ew->exec_result = nfc_hci_result_to_errno(result);
51 	if (hcp_ew->exec_result == 0)
52 		hcp_ew->result_skb = skb;
53 	else
54 		kfree_skb(skb);
55 	hcp_ew->exec_complete = true;
56 
57 	wake_up(hcp_ew->wq);
58 }
59 
60 static int nfc_hci_execute_cmd(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
61 			       const u8 *param, size_t param_len,
62 			       struct sk_buff **skb)
63 {
64 	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(ew_wq);
65 	struct hcp_exec_waiter hcp_ew;
66 	hcp_ew.wq = &ew_wq;
67 	hcp_ew.exec_complete = false;
68 	hcp_ew.result_skb = NULL;
69 
70 	pr_debug("through pipe=%d, cmd=%d, plen=%zd\n", pipe, cmd, param_len);
71 
72 	/* TODO: Define hci cmd execution delay. Should it be the same
73 	 * for all commands?
74 	 */
75 	hcp_ew.exec_result = nfc_hci_hcp_message_tx(hdev, pipe,
76 						    NFC_HCI_HCP_COMMAND, cmd,
77 						    param, param_len,
78 						    nfc_hci_execute_cb, &hcp_ew,
79 						    3000);
80 	if (hcp_ew.exec_result < 0)
81 		return hcp_ew.exec_result;
82 
83 	wait_event(ew_wq, hcp_ew.exec_complete == true);
84 
85 	if (hcp_ew.exec_result == 0) {
86 		if (skb)
87 			*skb = hcp_ew.result_skb;
88 		else
89 			kfree_skb(hcp_ew.result_skb);
90 	}
91 
92 	return hcp_ew.exec_result;
93 }
94 
95 int nfc_hci_send_event(struct nfc_hci_dev *hdev, u8 gate, u8 event,
96 		       const u8 *param, size_t param_len)
97 {
98 	u8 pipe;
99 
100 	pr_debug("%d to gate %d\n", event, gate);
101 
102 	pipe = hdev->gate2pipe[gate];
103 	if (pipe == NFC_HCI_INVALID_PIPE)
104 		return -EADDRNOTAVAIL;
105 
106 	return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_EVENT, event,
107 				      param, param_len, NULL, NULL, 0);
108 }
109 EXPORT_SYMBOL(nfc_hci_send_event);
110 
111 int nfc_hci_send_response(struct nfc_hci_dev *hdev, u8 gate, u8 response,
112 			  const u8 *param, size_t param_len)
113 {
114 	u8 pipe;
115 
116 	pr_debug("\n");
117 
118 	pipe = hdev->gate2pipe[gate];
119 	if (pipe == NFC_HCI_INVALID_PIPE)
120 		return -EADDRNOTAVAIL;
121 
122 	return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_RESPONSE,
123 				      response, param, param_len, NULL, NULL,
124 				      0);
125 }
126 EXPORT_SYMBOL(nfc_hci_send_response);
127 
128 /*
129  * Execute an hci command sent to gate.
130  * skb will contain response data if success. skb can be NULL if you are not
131  * interested by the response.
132  */
133 int nfc_hci_send_cmd(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
134 		     const u8 *param, size_t param_len, struct sk_buff **skb)
135 {
136 	u8 pipe;
137 
138 	pr_debug("\n");
139 
140 	pipe = hdev->gate2pipe[gate];
141 	if (pipe == NFC_HCI_INVALID_PIPE)
142 		return -EADDRNOTAVAIL;
143 
144 	return nfc_hci_execute_cmd(hdev, pipe, cmd, param, param_len, skb);
145 }
146 EXPORT_SYMBOL(nfc_hci_send_cmd);
147 
148 int nfc_hci_set_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
149 		      const u8 *param, size_t param_len)
150 {
151 	int r;
152 	u8 *tmp;
153 
154 	/* TODO ELa: reg idx must be inserted before param, but we don't want
155 	 * to ask the caller to do it to keep a simpler API.
156 	 * For now, just create a new temporary param buffer. This is far from
157 	 * optimal though, and the plan is to modify APIs to pass idx down to
158 	 * nfc_hci_hcp_message_tx where the frame is actually built, thereby
159 	 * eliminating the need for the temp allocation-copy here.
160 	 */
161 
162 	pr_debug("idx=%d to gate %d\n", idx, gate);
163 
164 	tmp = kmalloc(1 + param_len, GFP_KERNEL);
165 	if (tmp == NULL)
166 		return -ENOMEM;
167 
168 	*tmp = idx;
169 	memcpy(tmp + 1, param, param_len);
170 
171 	r = nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_SET_PARAMETER,
172 			     tmp, param_len + 1, NULL);
173 
174 	kfree(tmp);
175 
176 	return r;
177 }
178 EXPORT_SYMBOL(nfc_hci_set_param);
179 
180 int nfc_hci_get_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
181 		      struct sk_buff **skb)
182 {
183 	pr_debug("gate=%d regidx=%d\n", gate, idx);
184 
185 	return nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_GET_PARAMETER,
186 				&idx, 1, skb);
187 }
188 EXPORT_SYMBOL(nfc_hci_get_param);
189 
190 static int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)
191 {
192 	struct sk_buff *skb;
193 	int r;
194 
195 	pr_debug("pipe=%d\n", pipe);
196 
197 	r = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,
198 				NULL, 0, &skb);
199 	if (r == 0) {
200 		/* dest host other than host controller will send
201 		 * number of pipes already open on this gate before
202 		 * execution. The number can be found in skb->data[0]
203 		 */
204 		kfree_skb(skb);
205 	}
206 
207 	return r;
208 }
209 
210 static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)
211 {
212 	pr_debug("\n");
213 
214 	return nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,
215 				   NULL, 0, NULL);
216 }
217 
218 static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,
219 			      u8 dest_gate, int *result)
220 {
221 	struct sk_buff *skb;
222 	struct hci_create_pipe_params params;
223 	struct hci_create_pipe_resp *resp;
224 	u8 pipe;
225 
226 	pr_debug("gate=%d\n", dest_gate);
227 
228 	params.src_gate = NFC_HCI_ADMIN_GATE;
229 	params.dest_host = dest_host;
230 	params.dest_gate = dest_gate;
231 
232 	*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
233 				      NFC_HCI_ADM_CREATE_PIPE,
234 				      (u8 *) &params, sizeof(params), &skb);
235 	if (*result == 0) {
236 		resp = (struct hci_create_pipe_resp *)skb->data;
237 		pipe = resp->pipe;
238 		kfree_skb(skb);
239 
240 		pr_debug("pipe created=%d\n", pipe);
241 
242 		return pipe;
243 	} else
244 		return NFC_HCI_INVALID_PIPE;
245 }
246 
247 static int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)
248 {
249 	pr_debug("\n");
250 
251 	return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
252 				   NFC_HCI_ADM_DELETE_PIPE, &pipe, 1, NULL);
253 }
254 
255 static int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)
256 {
257 	int r;
258 
259 	u8 param[2];
260 
261 	/* TODO: Find out what the identity reference data is
262 	 * and fill param with it. HCI spec 6.1.3.5 */
263 
264 	pr_debug("\n");
265 
266 	r = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
267 				NFC_HCI_ADM_CLEAR_ALL_PIPE, param, 2, NULL);
268 
269 	return 0;
270 }
271 
272 int nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)
273 {
274 	int r;
275 	u8 pipe = hdev->gate2pipe[gate];
276 
277 	pr_debug("\n");
278 
279 	if (pipe == NFC_HCI_INVALID_PIPE)
280 		return -EADDRNOTAVAIL;
281 
282 	r = nfc_hci_close_pipe(hdev, pipe);
283 	if (r < 0)
284 		return r;
285 
286 	if (pipe != NFC_HCI_LINK_MGMT_PIPE && pipe != NFC_HCI_ADMIN_PIPE) {
287 		r = nfc_hci_delete_pipe(hdev, pipe);
288 		if (r < 0)
289 			return r;
290 	}
291 
292 	hdev->gate2pipe[gate] = NFC_HCI_INVALID_PIPE;
293 
294 	return 0;
295 }
296 EXPORT_SYMBOL(nfc_hci_disconnect_gate);
297 
298 int nfc_hci_disconnect_all_gates(struct nfc_hci_dev *hdev)
299 {
300 	int r;
301 
302 	pr_debug("\n");
303 
304 	r = nfc_hci_clear_all_pipes(hdev);
305 	if (r < 0)
306 		return r;
307 
308 	memset(hdev->gate2pipe, NFC_HCI_INVALID_PIPE, sizeof(hdev->gate2pipe));
309 
310 	return 0;
311 }
312 EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);
313 
314 int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate)
315 {
316 	u8 pipe = NFC_HCI_INVALID_PIPE;
317 	bool pipe_created = false;
318 	int r;
319 
320 	pr_debug("\n");
321 
322 	if (hdev->gate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)
323 		return -EADDRINUSE;
324 
325 	switch (dest_gate) {
326 	case NFC_HCI_LINK_MGMT_GATE:
327 		pipe = NFC_HCI_LINK_MGMT_PIPE;
328 		break;
329 	case NFC_HCI_ADMIN_GATE:
330 		pipe = NFC_HCI_ADMIN_PIPE;
331 		break;
332 	default:
333 		pipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, &r);
334 		if (pipe == NFC_HCI_INVALID_PIPE)
335 			return r;
336 		pipe_created = true;
337 		break;
338 	}
339 
340 	r = nfc_hci_open_pipe(hdev, pipe);
341 	if (r < 0) {
342 		if (pipe_created)
343 			if (nfc_hci_delete_pipe(hdev, pipe) < 0) {
344 				/* TODO: Cannot clean by deleting pipe...
345 				 * -> inconsistent state */
346 			}
347 		return r;
348 	}
349 
350 	hdev->gate2pipe[dest_gate] = pipe;
351 
352 	return 0;
353 }
354 EXPORT_SYMBOL(nfc_hci_connect_gate);
355