xref: /openbmc/linux/net/nfc/nci/hci.c (revision 349f631d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  The NFC Controller Interface is the communication protocol between an
4  *  NFC Controller (NFCC) and a Device Host (DH).
5  *  This is the HCI over NCI implementation, as specified in the 10.2
6  *  section of the NCI 1.1 specification.
7  *
8  *  Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
9  */
10 
11 #include <linux/skbuff.h>
12 
13 #include "../nfc.h"
14 #include <net/nfc/nci.h>
15 #include <net/nfc/nci_core.h>
16 #include <linux/nfc.h>
17 
18 struct nci_data {
19 	u8 conn_id;
20 	u8 pipe;
21 	u8 cmd;
22 	const u8 *data;
23 	u32 data_len;
24 } __packed;
25 
26 struct nci_hci_create_pipe_params {
27 	u8 src_gate;
28 	u8 dest_host;
29 	u8 dest_gate;
30 } __packed;
31 
32 struct nci_hci_create_pipe_resp {
33 	u8 src_host;
34 	u8 src_gate;
35 	u8 dest_host;
36 	u8 dest_gate;
37 	u8 pipe;
38 } __packed;
39 
40 struct nci_hci_delete_pipe_noti {
41 	u8 pipe;
42 } __packed;
43 
44 struct nci_hci_all_pipe_cleared_noti {
45 	u8 host;
46 } __packed;
47 
48 struct nci_hcp_message {
49 	u8 header;      /* type -cmd,evt,rsp- + instruction */
50 	u8 data[];
51 } __packed;
52 
53 struct nci_hcp_packet {
54 	u8 header;      /* cbit+pipe */
55 	struct nci_hcp_message message;
56 } __packed;
57 
58 #define NCI_HCI_ANY_SET_PARAMETER  0x01
59 #define NCI_HCI_ANY_GET_PARAMETER  0x02
60 #define NCI_HCI_ANY_CLOSE_PIPE     0x04
61 #define NCI_HCI_ADM_CLEAR_ALL_PIPE 0x14
62 
63 #define NCI_HFP_NO_CHAINING        0x80
64 
65 #define NCI_NFCEE_ID_HCI                0x80
66 
67 #define NCI_EVT_HOT_PLUG           0x03
68 
69 #define NCI_HCI_ADMIN_PARAM_SESSION_IDENTITY       0x01
70 #define NCI_HCI_ADM_CREATE_PIPE			0x10
71 #define NCI_HCI_ADM_DELETE_PIPE			0x11
72 
73 /* HCP headers */
74 #define NCI_HCI_HCP_PACKET_HEADER_LEN      1
75 #define NCI_HCI_HCP_MESSAGE_HEADER_LEN     1
76 #define NCI_HCI_HCP_HEADER_LEN             2
77 
78 /* HCP types */
79 #define NCI_HCI_HCP_COMMAND        0x00
80 #define NCI_HCI_HCP_EVENT          0x01
81 #define NCI_HCI_HCP_RESPONSE       0x02
82 
83 #define NCI_HCI_ADM_NOTIFY_PIPE_CREATED     0x12
84 #define NCI_HCI_ADM_NOTIFY_PIPE_DELETED     0x13
85 #define NCI_HCI_ADM_NOTIFY_ALL_PIPE_CLEARED 0x15
86 
87 #define NCI_HCI_FRAGMENT           0x7f
88 #define NCI_HCP_HEADER(type, instr) ((((type) & 0x03) << 6) |\
89 				      ((instr) & 0x3f))
90 
91 #define NCI_HCP_MSG_GET_TYPE(header) ((header & 0xc0) >> 6)
92 #define NCI_HCP_MSG_GET_CMD(header)  (header & 0x3f)
93 #define NCI_HCP_MSG_GET_PIPE(header) (header & 0x7f)
94 
95 static int nci_hci_result_to_errno(u8 result)
96 {
97 	switch (result) {
98 	case NCI_HCI_ANY_OK:
99 		return 0;
100 	case NCI_HCI_ANY_E_REG_PAR_UNKNOWN:
101 		return -EOPNOTSUPP;
102 	case NCI_HCI_ANY_E_TIMEOUT:
103 		return -ETIME;
104 	default:
105 		return -1;
106 	}
107 }
108 
109 /* HCI core */
110 static void nci_hci_reset_pipes(struct nci_hci_dev *hdev)
111 {
112 	int i;
113 
114 	for (i = 0; i < NCI_HCI_MAX_PIPES; i++) {
115 		hdev->pipes[i].gate = NCI_HCI_INVALID_GATE;
116 		hdev->pipes[i].host = NCI_HCI_INVALID_HOST;
117 	}
118 	memset(hdev->gate2pipe, NCI_HCI_INVALID_PIPE, sizeof(hdev->gate2pipe));
119 }
120 
121 static void nci_hci_reset_pipes_per_host(struct nci_dev *ndev, u8 host)
122 {
123 	int i;
124 
125 	for (i = 0; i < NCI_HCI_MAX_PIPES; i++) {
126 		if (ndev->hci_dev->pipes[i].host == host) {
127 			ndev->hci_dev->pipes[i].gate = NCI_HCI_INVALID_GATE;
128 			ndev->hci_dev->pipes[i].host = NCI_HCI_INVALID_HOST;
129 		}
130 	}
131 }
132 
133 /* Fragment HCI data over NCI packet.
134  * NFC Forum NCI 10.2.2 Data Exchange:
135  * The payload of the Data Packets sent on the Logical Connection SHALL be
136  * valid HCP packets, as defined within [ETSI_102622]. Each Data Packet SHALL
137  * contain a single HCP packet. NCI Segmentation and Reassembly SHALL NOT be
138  * applied to Data Messages in either direction. The HCI fragmentation mechanism
139  * is used if required.
140  */
141 static int nci_hci_send_data(struct nci_dev *ndev, u8 pipe,
142 			     const u8 data_type, const u8 *data,
143 			     size_t data_len)
144 {
145 	const struct nci_conn_info *conn_info;
146 	struct sk_buff *skb;
147 	int len, i, r;
148 	u8 cb = pipe;
149 
150 	conn_info = ndev->hci_dev->conn_info;
151 	if (!conn_info)
152 		return -EPROTO;
153 
154 	i = 0;
155 	skb = nci_skb_alloc(ndev, conn_info->max_pkt_payload_len +
156 			    NCI_DATA_HDR_SIZE, GFP_KERNEL);
157 	if (!skb)
158 		return -ENOMEM;
159 
160 	skb_reserve(skb, NCI_DATA_HDR_SIZE + 2);
161 	*(u8 *)skb_push(skb, 1) = data_type;
162 
163 	do {
164 		/* If last packet add NCI_HFP_NO_CHAINING */
165 		if (i + conn_info->max_pkt_payload_len -
166 		    (skb->len + 1) >= data_len) {
167 			cb |= NCI_HFP_NO_CHAINING;
168 			len = data_len - i;
169 		} else {
170 			len = conn_info->max_pkt_payload_len - skb->len - 1;
171 		}
172 
173 		*(u8 *)skb_push(skb, 1) = cb;
174 
175 		if (len > 0)
176 			skb_put_data(skb, data + i, len);
177 
178 		r = nci_send_data(ndev, conn_info->conn_id, skb);
179 		if (r < 0)
180 			return r;
181 
182 		i += len;
183 
184 		if (i < data_len) {
185 			skb = nci_skb_alloc(ndev,
186 					    conn_info->max_pkt_payload_len +
187 					    NCI_DATA_HDR_SIZE, GFP_KERNEL);
188 			if (!skb)
189 				return -ENOMEM;
190 
191 			skb_reserve(skb, NCI_DATA_HDR_SIZE + 1);
192 		}
193 	} while (i < data_len);
194 
195 	return i;
196 }
197 
198 static void nci_hci_send_data_req(struct nci_dev *ndev, const void *opt)
199 {
200 	const struct nci_data *data = opt;
201 
202 	nci_hci_send_data(ndev, data->pipe, data->cmd,
203 			  data->data, data->data_len);
204 }
205 
206 int nci_hci_send_event(struct nci_dev *ndev, u8 gate, u8 event,
207 		       const u8 *param, size_t param_len)
208 {
209 	u8 pipe = ndev->hci_dev->gate2pipe[gate];
210 
211 	if (pipe == NCI_HCI_INVALID_PIPE)
212 		return -EADDRNOTAVAIL;
213 
214 	return nci_hci_send_data(ndev, pipe,
215 			NCI_HCP_HEADER(NCI_HCI_HCP_EVENT, event),
216 			param, param_len);
217 }
218 EXPORT_SYMBOL(nci_hci_send_event);
219 
220 int nci_hci_send_cmd(struct nci_dev *ndev, u8 gate, u8 cmd,
221 		     const u8 *param, size_t param_len,
222 		     struct sk_buff **skb)
223 {
224 	const struct nci_hcp_message *message;
225 	const struct nci_conn_info *conn_info;
226 	struct nci_data data;
227 	int r;
228 	u8 pipe = ndev->hci_dev->gate2pipe[gate];
229 
230 	if (pipe == NCI_HCI_INVALID_PIPE)
231 		return -EADDRNOTAVAIL;
232 
233 	conn_info = ndev->hci_dev->conn_info;
234 	if (!conn_info)
235 		return -EPROTO;
236 
237 	data.conn_id = conn_info->conn_id;
238 	data.pipe = pipe;
239 	data.cmd = NCI_HCP_HEADER(NCI_HCI_HCP_COMMAND, cmd);
240 	data.data = param;
241 	data.data_len = param_len;
242 
243 	r = nci_request(ndev, nci_hci_send_data_req, &data,
244 			msecs_to_jiffies(NCI_DATA_TIMEOUT));
245 	if (r == NCI_STATUS_OK) {
246 		message = (struct nci_hcp_message *)conn_info->rx_skb->data;
247 		r = nci_hci_result_to_errno(
248 			NCI_HCP_MSG_GET_CMD(message->header));
249 		skb_pull(conn_info->rx_skb, NCI_HCI_HCP_MESSAGE_HEADER_LEN);
250 
251 		if (!r && skb)
252 			*skb = conn_info->rx_skb;
253 	}
254 
255 	return r;
256 }
257 EXPORT_SYMBOL(nci_hci_send_cmd);
258 
259 int nci_hci_clear_all_pipes(struct nci_dev *ndev)
260 {
261 	int r;
262 
263 	r = nci_hci_send_cmd(ndev, NCI_HCI_ADMIN_GATE,
264 			     NCI_HCI_ADM_CLEAR_ALL_PIPE, NULL, 0, NULL);
265 	if (r < 0)
266 		return r;
267 
268 	nci_hci_reset_pipes(ndev->hci_dev);
269 	return r;
270 }
271 EXPORT_SYMBOL(nci_hci_clear_all_pipes);
272 
273 static void nci_hci_event_received(struct nci_dev *ndev, u8 pipe,
274 				   u8 event, struct sk_buff *skb)
275 {
276 	if (ndev->ops->hci_event_received)
277 		ndev->ops->hci_event_received(ndev, pipe, event, skb);
278 }
279 
280 static void nci_hci_cmd_received(struct nci_dev *ndev, u8 pipe,
281 				 u8 cmd, struct sk_buff *skb)
282 {
283 	u8 gate = ndev->hci_dev->pipes[pipe].gate;
284 	u8 status = NCI_HCI_ANY_OK | ~NCI_HCI_FRAGMENT;
285 	u8 dest_gate, new_pipe;
286 	struct nci_hci_create_pipe_resp *create_info;
287 	struct nci_hci_delete_pipe_noti *delete_info;
288 	struct nci_hci_all_pipe_cleared_noti *cleared_info;
289 
290 	pr_debug("from gate %x pipe %x cmd %x\n", gate, pipe, cmd);
291 
292 	switch (cmd) {
293 	case NCI_HCI_ADM_NOTIFY_PIPE_CREATED:
294 		if (skb->len != 5) {
295 			status = NCI_HCI_ANY_E_NOK;
296 			goto exit;
297 		}
298 		create_info = (struct nci_hci_create_pipe_resp *)skb->data;
299 		dest_gate = create_info->dest_gate;
300 		new_pipe = create_info->pipe;
301 		if (new_pipe >= NCI_HCI_MAX_PIPES) {
302 			status = NCI_HCI_ANY_E_NOK;
303 			goto exit;
304 		}
305 
306 		/* Save the new created pipe and bind with local gate,
307 		 * the description for skb->data[3] is destination gate id
308 		 * but since we received this cmd from host controller, we
309 		 * are the destination and it is our local gate
310 		 */
311 		ndev->hci_dev->gate2pipe[dest_gate] = new_pipe;
312 		ndev->hci_dev->pipes[new_pipe].gate = dest_gate;
313 		ndev->hci_dev->pipes[new_pipe].host =
314 						create_info->src_host;
315 		break;
316 	case NCI_HCI_ANY_OPEN_PIPE:
317 		/* If the pipe is not created report an error */
318 		if (gate == NCI_HCI_INVALID_GATE) {
319 			status = NCI_HCI_ANY_E_NOK;
320 			goto exit;
321 		}
322 		break;
323 	case NCI_HCI_ADM_NOTIFY_PIPE_DELETED:
324 		if (skb->len != 1) {
325 			status = NCI_HCI_ANY_E_NOK;
326 			goto exit;
327 		}
328 		delete_info = (struct nci_hci_delete_pipe_noti *)skb->data;
329 		if (delete_info->pipe >= NCI_HCI_MAX_PIPES) {
330 			status = NCI_HCI_ANY_E_NOK;
331 			goto exit;
332 		}
333 
334 		ndev->hci_dev->pipes[delete_info->pipe].gate =
335 						NCI_HCI_INVALID_GATE;
336 		ndev->hci_dev->pipes[delete_info->pipe].host =
337 						NCI_HCI_INVALID_HOST;
338 		break;
339 	case NCI_HCI_ADM_NOTIFY_ALL_PIPE_CLEARED:
340 		if (skb->len != 1) {
341 			status = NCI_HCI_ANY_E_NOK;
342 			goto exit;
343 		}
344 
345 		cleared_info =
346 			(struct nci_hci_all_pipe_cleared_noti *)skb->data;
347 		nci_hci_reset_pipes_per_host(ndev, cleared_info->host);
348 		break;
349 	default:
350 		pr_debug("Discarded unknown cmd %x to gate %x\n", cmd, gate);
351 		break;
352 	}
353 
354 	if (ndev->ops->hci_cmd_received)
355 		ndev->ops->hci_cmd_received(ndev, pipe, cmd, skb);
356 
357 exit:
358 	nci_hci_send_data(ndev, pipe, status, NULL, 0);
359 
360 	kfree_skb(skb);
361 }
362 
363 static void nci_hci_resp_received(struct nci_dev *ndev, u8 pipe,
364 				  struct sk_buff *skb)
365 {
366 	struct nci_conn_info *conn_info;
367 
368 	conn_info = ndev->hci_dev->conn_info;
369 	if (!conn_info)
370 		goto exit;
371 
372 	conn_info->rx_skb = skb;
373 
374 exit:
375 	nci_req_complete(ndev, NCI_STATUS_OK);
376 }
377 
378 /* Receive hcp message for pipe, with type and cmd.
379  * skb contains optional message data only.
380  */
381 static void nci_hci_hcp_message_rx(struct nci_dev *ndev, u8 pipe,
382 				   u8 type, u8 instruction, struct sk_buff *skb)
383 {
384 	switch (type) {
385 	case NCI_HCI_HCP_RESPONSE:
386 		nci_hci_resp_received(ndev, pipe, skb);
387 		break;
388 	case NCI_HCI_HCP_COMMAND:
389 		nci_hci_cmd_received(ndev, pipe, instruction, skb);
390 		break;
391 	case NCI_HCI_HCP_EVENT:
392 		nci_hci_event_received(ndev, pipe, instruction, skb);
393 		break;
394 	default:
395 		pr_err("UNKNOWN MSG Type %d, instruction=%d\n",
396 		       type, instruction);
397 		kfree_skb(skb);
398 		break;
399 	}
400 
401 	nci_req_complete(ndev, NCI_STATUS_OK);
402 }
403 
404 static void nci_hci_msg_rx_work(struct work_struct *work)
405 {
406 	struct nci_hci_dev *hdev =
407 		container_of(work, struct nci_hci_dev, msg_rx_work);
408 	struct sk_buff *skb;
409 	const struct nci_hcp_message *message;
410 	u8 pipe, type, instruction;
411 
412 	while ((skb = skb_dequeue(&hdev->msg_rx_queue)) != NULL) {
413 		pipe = NCI_HCP_MSG_GET_PIPE(skb->data[0]);
414 		skb_pull(skb, NCI_HCI_HCP_PACKET_HEADER_LEN);
415 		message = (struct nci_hcp_message *)skb->data;
416 		type = NCI_HCP_MSG_GET_TYPE(message->header);
417 		instruction = NCI_HCP_MSG_GET_CMD(message->header);
418 		skb_pull(skb, NCI_HCI_HCP_MESSAGE_HEADER_LEN);
419 
420 		nci_hci_hcp_message_rx(hdev->ndev, pipe,
421 				       type, instruction, skb);
422 	}
423 }
424 
425 void nci_hci_data_received_cb(void *context,
426 			      struct sk_buff *skb, int err)
427 {
428 	struct nci_dev *ndev = (struct nci_dev *)context;
429 	struct nci_hcp_packet *packet;
430 	u8 pipe, type;
431 	struct sk_buff *hcp_skb;
432 	struct sk_buff *frag_skb;
433 	int msg_len;
434 
435 	pr_debug("\n");
436 
437 	if (err) {
438 		nci_req_complete(ndev, err);
439 		return;
440 	}
441 
442 	packet = (struct nci_hcp_packet *)skb->data;
443 	if ((packet->header & ~NCI_HCI_FRAGMENT) == 0) {
444 		skb_queue_tail(&ndev->hci_dev->rx_hcp_frags, skb);
445 		return;
446 	}
447 
448 	/* it's the last fragment. Does it need re-aggregation? */
449 	if (skb_queue_len(&ndev->hci_dev->rx_hcp_frags)) {
450 		pipe = NCI_HCP_MSG_GET_PIPE(packet->header);
451 		skb_queue_tail(&ndev->hci_dev->rx_hcp_frags, skb);
452 
453 		msg_len = 0;
454 		skb_queue_walk(&ndev->hci_dev->rx_hcp_frags, frag_skb) {
455 			msg_len += (frag_skb->len -
456 				    NCI_HCI_HCP_PACKET_HEADER_LEN);
457 		}
458 
459 		hcp_skb = nfc_alloc_recv_skb(NCI_HCI_HCP_PACKET_HEADER_LEN +
460 					     msg_len, GFP_KERNEL);
461 		if (!hcp_skb) {
462 			nci_req_complete(ndev, -ENOMEM);
463 			return;
464 		}
465 
466 		skb_put_u8(hcp_skb, pipe);
467 
468 		skb_queue_walk(&ndev->hci_dev->rx_hcp_frags, frag_skb) {
469 			msg_len = frag_skb->len - NCI_HCI_HCP_PACKET_HEADER_LEN;
470 			skb_put_data(hcp_skb,
471 				     frag_skb->data + NCI_HCI_HCP_PACKET_HEADER_LEN,
472 				     msg_len);
473 		}
474 
475 		skb_queue_purge(&ndev->hci_dev->rx_hcp_frags);
476 	} else {
477 		packet->header &= NCI_HCI_FRAGMENT;
478 		hcp_skb = skb;
479 	}
480 
481 	/* if this is a response, dispatch immediately to
482 	 * unblock waiting cmd context. Otherwise, enqueue to dispatch
483 	 * in separate context where handler can also execute command.
484 	 */
485 	packet = (struct nci_hcp_packet *)hcp_skb->data;
486 	type = NCI_HCP_MSG_GET_TYPE(packet->message.header);
487 	if (type == NCI_HCI_HCP_RESPONSE) {
488 		pipe = NCI_HCP_MSG_GET_PIPE(packet->header);
489 		skb_pull(hcp_skb, NCI_HCI_HCP_PACKET_HEADER_LEN);
490 		nci_hci_hcp_message_rx(ndev, pipe, type,
491 				       NCI_STATUS_OK, hcp_skb);
492 	} else {
493 		skb_queue_tail(&ndev->hci_dev->msg_rx_queue, hcp_skb);
494 		schedule_work(&ndev->hci_dev->msg_rx_work);
495 	}
496 }
497 
498 int nci_hci_open_pipe(struct nci_dev *ndev, u8 pipe)
499 {
500 	struct nci_data data;
501 	const struct nci_conn_info *conn_info;
502 
503 	conn_info = ndev->hci_dev->conn_info;
504 	if (!conn_info)
505 		return -EPROTO;
506 
507 	data.conn_id = conn_info->conn_id;
508 	data.pipe = pipe;
509 	data.cmd = NCI_HCP_HEADER(NCI_HCI_HCP_COMMAND,
510 				       NCI_HCI_ANY_OPEN_PIPE);
511 	data.data = NULL;
512 	data.data_len = 0;
513 
514 	return nci_request(ndev, nci_hci_send_data_req, &data,
515 			   msecs_to_jiffies(NCI_DATA_TIMEOUT));
516 }
517 EXPORT_SYMBOL(nci_hci_open_pipe);
518 
519 static u8 nci_hci_create_pipe(struct nci_dev *ndev, u8 dest_host,
520 			      u8 dest_gate, int *result)
521 {
522 	u8 pipe;
523 	struct sk_buff *skb;
524 	struct nci_hci_create_pipe_params params;
525 	const struct nci_hci_create_pipe_resp *resp;
526 
527 	pr_debug("gate=%d\n", dest_gate);
528 
529 	params.src_gate = NCI_HCI_ADMIN_GATE;
530 	params.dest_host = dest_host;
531 	params.dest_gate = dest_gate;
532 
533 	*result = nci_hci_send_cmd(ndev, NCI_HCI_ADMIN_GATE,
534 				   NCI_HCI_ADM_CREATE_PIPE,
535 				   (u8 *)&params, sizeof(params), &skb);
536 	if (*result < 0)
537 		return NCI_HCI_INVALID_PIPE;
538 
539 	resp = (struct nci_hci_create_pipe_resp *)skb->data;
540 	pipe = resp->pipe;
541 	kfree_skb(skb);
542 
543 	pr_debug("pipe created=%d\n", pipe);
544 
545 	return pipe;
546 }
547 
548 static int nci_hci_delete_pipe(struct nci_dev *ndev, u8 pipe)
549 {
550 	pr_debug("\n");
551 
552 	return nci_hci_send_cmd(ndev, NCI_HCI_ADMIN_GATE,
553 				NCI_HCI_ADM_DELETE_PIPE, &pipe, 1, NULL);
554 }
555 
556 int nci_hci_set_param(struct nci_dev *ndev, u8 gate, u8 idx,
557 		      const u8 *param, size_t param_len)
558 {
559 	const struct nci_hcp_message *message;
560 	const struct nci_conn_info *conn_info;
561 	struct nci_data data;
562 	int r;
563 	u8 *tmp;
564 	u8 pipe = ndev->hci_dev->gate2pipe[gate];
565 
566 	pr_debug("idx=%d to gate %d\n", idx, gate);
567 
568 	if (pipe == NCI_HCI_INVALID_PIPE)
569 		return -EADDRNOTAVAIL;
570 
571 	conn_info = ndev->hci_dev->conn_info;
572 	if (!conn_info)
573 		return -EPROTO;
574 
575 	tmp = kmalloc(1 + param_len, GFP_KERNEL);
576 	if (!tmp)
577 		return -ENOMEM;
578 
579 	*tmp = idx;
580 	memcpy(tmp + 1, param, param_len);
581 
582 	data.conn_id = conn_info->conn_id;
583 	data.pipe = pipe;
584 	data.cmd = NCI_HCP_HEADER(NCI_HCI_HCP_COMMAND,
585 				       NCI_HCI_ANY_SET_PARAMETER);
586 	data.data = tmp;
587 	data.data_len = param_len + 1;
588 
589 	r = nci_request(ndev, nci_hci_send_data_req, &data,
590 			msecs_to_jiffies(NCI_DATA_TIMEOUT));
591 	if (r == NCI_STATUS_OK) {
592 		message = (struct nci_hcp_message *)conn_info->rx_skb->data;
593 		r = nci_hci_result_to_errno(
594 			NCI_HCP_MSG_GET_CMD(message->header));
595 		skb_pull(conn_info->rx_skb, NCI_HCI_HCP_MESSAGE_HEADER_LEN);
596 	}
597 
598 	kfree(tmp);
599 	return r;
600 }
601 EXPORT_SYMBOL(nci_hci_set_param);
602 
603 int nci_hci_get_param(struct nci_dev *ndev, u8 gate, u8 idx,
604 		      struct sk_buff **skb)
605 {
606 	const struct nci_hcp_message *message;
607 	const struct nci_conn_info *conn_info;
608 	struct nci_data data;
609 	int r;
610 	u8 pipe = ndev->hci_dev->gate2pipe[gate];
611 
612 	pr_debug("idx=%d to gate %d\n", idx, gate);
613 
614 	if (pipe == NCI_HCI_INVALID_PIPE)
615 		return -EADDRNOTAVAIL;
616 
617 	conn_info = ndev->hci_dev->conn_info;
618 	if (!conn_info)
619 		return -EPROTO;
620 
621 	data.conn_id = conn_info->conn_id;
622 	data.pipe = pipe;
623 	data.cmd = NCI_HCP_HEADER(NCI_HCI_HCP_COMMAND,
624 				  NCI_HCI_ANY_GET_PARAMETER);
625 	data.data = &idx;
626 	data.data_len = 1;
627 
628 	r = nci_request(ndev, nci_hci_send_data_req, &data,
629 			msecs_to_jiffies(NCI_DATA_TIMEOUT));
630 
631 	if (r == NCI_STATUS_OK) {
632 		message = (struct nci_hcp_message *)conn_info->rx_skb->data;
633 		r = nci_hci_result_to_errno(
634 			NCI_HCP_MSG_GET_CMD(message->header));
635 		skb_pull(conn_info->rx_skb, NCI_HCI_HCP_MESSAGE_HEADER_LEN);
636 
637 		if (!r && skb)
638 			*skb = conn_info->rx_skb;
639 	}
640 
641 	return r;
642 }
643 EXPORT_SYMBOL(nci_hci_get_param);
644 
645 int nci_hci_connect_gate(struct nci_dev *ndev,
646 			 u8 dest_host, u8 dest_gate, u8 pipe)
647 {
648 	bool pipe_created = false;
649 	int r;
650 
651 	if (pipe == NCI_HCI_DO_NOT_OPEN_PIPE)
652 		return 0;
653 
654 	if (ndev->hci_dev->gate2pipe[dest_gate] != NCI_HCI_INVALID_PIPE)
655 		return -EADDRINUSE;
656 
657 	if (pipe != NCI_HCI_INVALID_PIPE)
658 		goto open_pipe;
659 
660 	switch (dest_gate) {
661 	case NCI_HCI_LINK_MGMT_GATE:
662 		pipe = NCI_HCI_LINK_MGMT_PIPE;
663 	break;
664 	case NCI_HCI_ADMIN_GATE:
665 		pipe = NCI_HCI_ADMIN_PIPE;
666 	break;
667 	default:
668 		pipe = nci_hci_create_pipe(ndev, dest_host, dest_gate, &r);
669 		if (pipe == NCI_HCI_INVALID_PIPE)
670 			return r;
671 		pipe_created = true;
672 		break;
673 	}
674 
675 open_pipe:
676 	r = nci_hci_open_pipe(ndev, pipe);
677 	if (r < 0) {
678 		if (pipe_created) {
679 			if (nci_hci_delete_pipe(ndev, pipe) < 0) {
680 				/* TODO: Cannot clean by deleting pipe...
681 				 * -> inconsistent state
682 				 */
683 			}
684 		}
685 		return r;
686 	}
687 
688 	ndev->hci_dev->pipes[pipe].gate = dest_gate;
689 	ndev->hci_dev->pipes[pipe].host = dest_host;
690 	ndev->hci_dev->gate2pipe[dest_gate] = pipe;
691 
692 	return 0;
693 }
694 EXPORT_SYMBOL(nci_hci_connect_gate);
695 
696 static int nci_hci_dev_connect_gates(struct nci_dev *ndev,
697 				     u8 gate_count,
698 				     const struct nci_hci_gate *gates)
699 {
700 	int r;
701 
702 	while (gate_count--) {
703 		r = nci_hci_connect_gate(ndev, gates->dest_host,
704 					 gates->gate, gates->pipe);
705 		if (r < 0)
706 			return r;
707 		gates++;
708 	}
709 
710 	return 0;
711 }
712 
713 int nci_hci_dev_session_init(struct nci_dev *ndev)
714 {
715 	struct nci_conn_info *conn_info;
716 	struct sk_buff *skb;
717 	int r;
718 
719 	ndev->hci_dev->count_pipes = 0;
720 	ndev->hci_dev->expected_pipes = 0;
721 
722 	conn_info = ndev->hci_dev->conn_info;
723 	if (!conn_info)
724 		return -EPROTO;
725 
726 	conn_info->data_exchange_cb = nci_hci_data_received_cb;
727 	conn_info->data_exchange_cb_context = ndev;
728 
729 	nci_hci_reset_pipes(ndev->hci_dev);
730 
731 	if (ndev->hci_dev->init_data.gates[0].gate != NCI_HCI_ADMIN_GATE)
732 		return -EPROTO;
733 
734 	r = nci_hci_connect_gate(ndev,
735 				 ndev->hci_dev->init_data.gates[0].dest_host,
736 				 ndev->hci_dev->init_data.gates[0].gate,
737 				 ndev->hci_dev->init_data.gates[0].pipe);
738 	if (r < 0)
739 		return r;
740 
741 	r = nci_hci_get_param(ndev, NCI_HCI_ADMIN_GATE,
742 			      NCI_HCI_ADMIN_PARAM_SESSION_IDENTITY, &skb);
743 	if (r < 0)
744 		return r;
745 
746 	if (skb->len &&
747 	    skb->len == strlen(ndev->hci_dev->init_data.session_id) &&
748 	    !memcmp(ndev->hci_dev->init_data.session_id, skb->data, skb->len) &&
749 	    ndev->ops->hci_load_session) {
750 		/* Restore gate<->pipe table from some proprietary location. */
751 		r = ndev->ops->hci_load_session(ndev);
752 	} else {
753 		r = nci_hci_clear_all_pipes(ndev);
754 		if (r < 0)
755 			goto exit;
756 
757 		r = nci_hci_dev_connect_gates(ndev,
758 					      ndev->hci_dev->init_data.gate_count,
759 					      ndev->hci_dev->init_data.gates);
760 		if (r < 0)
761 			goto exit;
762 
763 		r = nci_hci_set_param(ndev, NCI_HCI_ADMIN_GATE,
764 				      NCI_HCI_ADMIN_PARAM_SESSION_IDENTITY,
765 				      ndev->hci_dev->init_data.session_id,
766 				      strlen(ndev->hci_dev->init_data.session_id));
767 	}
768 
769 exit:
770 	kfree_skb(skb);
771 
772 	return r;
773 }
774 EXPORT_SYMBOL(nci_hci_dev_session_init);
775 
776 struct nci_hci_dev *nci_hci_allocate(struct nci_dev *ndev)
777 {
778 	struct nci_hci_dev *hdev;
779 
780 	hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
781 	if (!hdev)
782 		return NULL;
783 
784 	skb_queue_head_init(&hdev->rx_hcp_frags);
785 	INIT_WORK(&hdev->msg_rx_work, nci_hci_msg_rx_work);
786 	skb_queue_head_init(&hdev->msg_rx_queue);
787 	hdev->ndev = ndev;
788 
789 	return hdev;
790 }
791 
792 void nci_hci_deallocate(struct nci_dev *ndev)
793 {
794 	kfree(ndev->hci_dev);
795 }
796