xref: /freebsd/sys/dev/hyperv/utilities/hv_kvp.c (revision 911f0260390e18cf85f3dbf2c719b593efdc1e3c)
1 /*-
2  * Copyright (c) 2014,2016-2017 Microsoft Corp.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 /*
28  *	Author:	Sainath Varanasi.
29  *	Date:	4/2012
30  *	Email:	bsdic@microsoft.com
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/param.h>
37 #include <sys/kernel.h>
38 #include <sys/conf.h>
39 #include <sys/uio.h>
40 #include <sys/bus.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/module.h>
44 #include <sys/reboot.h>
45 #include <sys/lock.h>
46 #include <sys/taskqueue.h>
47 #include <sys/selinfo.h>
48 #include <sys/sysctl.h>
49 #include <sys/poll.h>
50 #include <sys/proc.h>
51 #include <sys/kthread.h>
52 #include <sys/syscallsubr.h>
53 #include <sys/sysproto.h>
54 #include <sys/un.h>
55 #include <sys/endian.h>
56 #include <sys/_null.h>
57 #include <sys/sema.h>
58 #include <sys/signal.h>
59 #include <sys/syslog.h>
60 #include <sys/systm.h>
61 #include <sys/mutex.h>
62 
63 #include <dev/hyperv/include/hyperv.h>
64 #include <dev/hyperv/include/vmbus.h>
65 #include <dev/hyperv/utilities/hv_utilreg.h>
66 #include <dev/hyperv/utilities/vmbus_icreg.h>
67 #include <dev/hyperv/utilities/vmbus_icvar.h>
68 
69 #include "unicode.h"
70 #include "hv_kvp.h"
71 #include "vmbus_if.h"
72 
73 /* hv_kvp defines */
74 #define BUFFERSIZE	sizeof(struct hv_kvp_msg)
75 #define kvp_hdr		hdr.kvp_hdr
76 
77 #define KVP_FWVER_MAJOR		3
78 #define KVP_FWVER		VMBUS_IC_VERSION(KVP_FWVER_MAJOR, 0)
79 
80 #define KVP_MSGVER_MAJOR	4
81 #define KVP_MSGVER		VMBUS_IC_VERSION(KVP_MSGVER_MAJOR, 0)
82 
83 /* hv_kvp debug control */
84 static int hv_kvp_log = 0;
85 
86 #define	hv_kvp_log_error(...)	do {				\
87 	if (hv_kvp_log > 0)				\
88 		log(LOG_ERR, "hv_kvp: " __VA_ARGS__);	\
89 } while (0)
90 
91 #define	hv_kvp_log_info(...) do {				\
92 	if (hv_kvp_log > 1)				\
93 		log(LOG_INFO, "hv_kvp: " __VA_ARGS__);		\
94 } while (0)
95 
96 static const struct vmbus_ic_desc vmbus_kvp_descs[] = {
97 	{
98 		.ic_guid = { .hv_guid = {
99 		    0xe7, 0xf4, 0xa0, 0xa9, 0x45, 0x5a, 0x96, 0x4d,
100 		    0xb8, 0x27, 0x8a, 0x84, 0x1e, 0x8c, 0x3,  0xe6 } },
101 		.ic_desc = "Hyper-V KVP"
102 	},
103 	VMBUS_IC_DESC_END
104 };
105 
106 /* character device prototypes */
107 static d_open_t		hv_kvp_dev_open;
108 static d_close_t	hv_kvp_dev_close;
109 static d_read_t		hv_kvp_dev_daemon_read;
110 static d_write_t	hv_kvp_dev_daemon_write;
111 static d_poll_t		hv_kvp_dev_daemon_poll;
112 
113 /* hv_kvp character device structure */
114 static struct cdevsw hv_kvp_cdevsw =
115 {
116 	.d_version	= D_VERSION,
117 	.d_open		= hv_kvp_dev_open,
118 	.d_close	= hv_kvp_dev_close,
119 	.d_read		= hv_kvp_dev_daemon_read,
120 	.d_write	= hv_kvp_dev_daemon_write,
121 	.d_poll		= hv_kvp_dev_daemon_poll,
122 	.d_name		= "hv_kvp_dev",
123 };
124 
125 
126 /*
127  * Global state to track and synchronize multiple
128  * KVP transaction requests from the host.
129  */
130 typedef struct hv_kvp_sc {
131 	struct vmbus_ic_softc	util_sc;
132 	device_t		dev;
133 
134 	/* Unless specified the pending mutex should be
135 	 * used to alter the values of the following parameters:
136 	 * 1. req_in_progress
137 	 * 2. req_timed_out
138 	 */
139 	struct mtx		pending_mutex;
140 
141 	struct task		task;
142 
143 	/* To track if transaction is active or not */
144 	boolean_t		req_in_progress;
145 	/* Tracks if daemon did not reply back in time */
146 	boolean_t		req_timed_out;
147 	/* Tracks if daemon is serving a request currently */
148 	boolean_t		daemon_busy;
149 
150 	/* Length of host message */
151 	uint32_t		host_msg_len;
152 
153 	/* Host message id */
154 	uint64_t		host_msg_id;
155 
156 	/* Current kvp message from the host */
157 	struct hv_kvp_msg	*host_kvp_msg;
158 
159 	 /* Current kvp message for daemon */
160 	struct hv_kvp_msg	daemon_kvp_msg;
161 
162 	/* Rcv buffer for communicating with the host*/
163 	uint8_t			*rcv_buf;
164 
165 	/* Device semaphore to control communication */
166 	struct sema		dev_sema;
167 
168 	/* Indicates if daemon registered with driver */
169 	boolean_t		register_done;
170 
171 	/* Character device status */
172 	boolean_t		dev_accessed;
173 
174 	struct cdev *hv_kvp_dev;
175 
176 	struct proc *daemon_task;
177 
178 	struct selinfo hv_kvp_selinfo;
179 } hv_kvp_sc;
180 
181 /* hv_kvp prototypes */
182 static int	hv_kvp_req_in_progress(hv_kvp_sc *sc);
183 static void	hv_kvp_transaction_init(hv_kvp_sc *sc, uint32_t, uint64_t, uint8_t *);
184 static void	hv_kvp_send_msg_to_daemon(hv_kvp_sc *sc);
185 static void	hv_kvp_process_request(void *context, int pending);
186 
187 /*
188  * hv_kvp low level functions
189  */
190 
191 /*
192  * Check if kvp transaction is in progres
193  */
194 static int
195 hv_kvp_req_in_progress(hv_kvp_sc *sc)
196 {
197 
198 	return (sc->req_in_progress);
199 }
200 
201 
202 /*
203  * This routine is called whenever a message is received from the host
204  */
205 static void
206 hv_kvp_transaction_init(hv_kvp_sc *sc, uint32_t rcv_len,
207 			uint64_t request_id, uint8_t *rcv_buf)
208 {
209 
210 	/* Store all the relevant message details in the global structure */
211 	/* Do not need to use mutex for req_in_progress here */
212 	sc->req_in_progress = true;
213 	sc->host_msg_len = rcv_len;
214 	sc->host_msg_id = request_id;
215 	sc->rcv_buf = rcv_buf;
216 	sc->host_kvp_msg = (struct hv_kvp_msg *)&rcv_buf[
217 	    sizeof(struct hv_vmbus_pipe_hdr) +
218 	    sizeof(struct hv_vmbus_icmsg_hdr)];
219 }
220 
221 /*
222  * Convert ip related info in umsg from utf8 to utf16 and store in hmsg
223  */
224 static int
225 hv_kvp_convert_utf8_ipinfo_to_utf16(struct hv_kvp_msg *umsg,
226 				    struct hv_kvp_ip_msg *host_ip_msg)
227 {
228 	int err_ip, err_subnet, err_gway, err_dns, err_adap;
229 	int UNUSED_FLAG = 1;
230 
231 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.ip_addr,
232 	    MAX_IP_ADDR_SIZE,
233 	    (char *)umsg->body.kvp_ip_val.ip_addr,
234 	    strlen((char *)umsg->body.kvp_ip_val.ip_addr),
235 	    UNUSED_FLAG,
236 	    &err_ip);
237 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.sub_net,
238 	    MAX_IP_ADDR_SIZE,
239 	    (char *)umsg->body.kvp_ip_val.sub_net,
240 	    strlen((char *)umsg->body.kvp_ip_val.sub_net),
241 	    UNUSED_FLAG,
242 	    &err_subnet);
243 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.gate_way,
244 	    MAX_GATEWAY_SIZE,
245 	    (char *)umsg->body.kvp_ip_val.gate_way,
246 	    strlen((char *)umsg->body.kvp_ip_val.gate_way),
247 	    UNUSED_FLAG,
248 	    &err_gway);
249 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.dns_addr,
250 	    MAX_IP_ADDR_SIZE,
251 	    (char *)umsg->body.kvp_ip_val.dns_addr,
252 	    strlen((char *)umsg->body.kvp_ip_val.dns_addr),
253 	    UNUSED_FLAG,
254 	    &err_dns);
255 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.adapter_id,
256 	    MAX_ADAPTER_ID_SIZE,
257 	    (char *)umsg->body.kvp_ip_val.adapter_id,
258 	    strlen((char *)umsg->body.kvp_ip_val.adapter_id),
259 	    UNUSED_FLAG,
260 	    &err_adap);
261 
262 	host_ip_msg->kvp_ip_val.dhcp_enabled = umsg->body.kvp_ip_val.dhcp_enabled;
263 	host_ip_msg->kvp_ip_val.addr_family = umsg->body.kvp_ip_val.addr_family;
264 
265 	return (err_ip | err_subnet | err_gway | err_dns | err_adap);
266 }
267 
268 
269 /*
270  * Convert ip related info in hmsg from utf16 to utf8 and store in umsg
271  */
272 static int
273 hv_kvp_convert_utf16_ipinfo_to_utf8(struct hv_kvp_ip_msg *host_ip_msg,
274 				    struct hv_kvp_msg *umsg)
275 {
276 	int err_ip, err_subnet, err_gway, err_dns, err_adap;
277 	int UNUSED_FLAG = 1;
278 	device_t *devs;
279 	int devcnt;
280 
281 	/* IP Address */
282 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.ip_addr,
283 	    MAX_IP_ADDR_SIZE,
284 	    (uint16_t *)host_ip_msg->kvp_ip_val.ip_addr,
285 	    MAX_IP_ADDR_SIZE,
286 	    UNUSED_FLAG,
287 	    &err_ip);
288 
289 	/* Adapter ID : GUID */
290 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.adapter_id,
291 	    MAX_ADAPTER_ID_SIZE,
292 	    (uint16_t *)host_ip_msg->kvp_ip_val.adapter_id,
293 	    MAX_ADAPTER_ID_SIZE,
294 	    UNUSED_FLAG,
295 	    &err_adap);
296 
297 	if (devclass_get_devices(devclass_find("hn"), &devs, &devcnt) == 0) {
298 		for (devcnt = devcnt - 1; devcnt >= 0; devcnt--) {
299 			device_t dev = devs[devcnt];
300 			struct vmbus_channel *chan;
301 			char buf[HYPERV_GUID_STRLEN];
302 			int n;
303 
304 			chan = vmbus_get_channel(dev);
305 			n = hyperv_guid2str(vmbus_chan_guid_inst(chan), buf,
306 			    sizeof(buf));
307 
308 			/*
309 			 * The string in the 'kvp_ip_val.adapter_id' has
310 			 * braces around the GUID; skip the leading brace
311 			 * in 'kvp_ip_val.adapter_id'.
312 			 */
313 			if (strncmp(buf,
314 			    ((char *)&umsg->body.kvp_ip_val.adapter_id) + 1,
315 			    n) == 0) {
316 				strlcpy((char *)umsg->body.kvp_ip_val.adapter_id,
317 				    device_get_nameunit(dev), MAX_ADAPTER_ID_SIZE);
318 				break;
319 			}
320 		}
321 		free(devs, M_TEMP);
322 	}
323 
324 	/* Address Family , DHCP , SUBNET, Gateway, DNS */
325 	umsg->kvp_hdr.operation = host_ip_msg->operation;
326 	umsg->body.kvp_ip_val.addr_family = host_ip_msg->kvp_ip_val.addr_family;
327 	umsg->body.kvp_ip_val.dhcp_enabled = host_ip_msg->kvp_ip_val.dhcp_enabled;
328 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.sub_net, MAX_IP_ADDR_SIZE,
329 	    (uint16_t *)host_ip_msg->kvp_ip_val.sub_net,
330 	    MAX_IP_ADDR_SIZE,
331 	    UNUSED_FLAG,
332 	    &err_subnet);
333 
334 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.gate_way, MAX_GATEWAY_SIZE,
335 	    (uint16_t *)host_ip_msg->kvp_ip_val.gate_way,
336 	    MAX_GATEWAY_SIZE,
337 	    UNUSED_FLAG,
338 	    &err_gway);
339 
340 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.dns_addr, MAX_IP_ADDR_SIZE,
341 	    (uint16_t *)host_ip_msg->kvp_ip_val.dns_addr,
342 	    MAX_IP_ADDR_SIZE,
343 	    UNUSED_FLAG,
344 	    &err_dns);
345 
346 	return (err_ip | err_subnet | err_gway | err_dns | err_adap);
347 }
348 
349 
350 /*
351  * Prepare a user kvp msg based on host kvp msg (utf16 to utf8)
352  * Ensure utf16_utf8 takes care of the additional string terminating char!!
353  */
354 static void
355 hv_kvp_convert_hostmsg_to_usermsg(struct hv_kvp_msg *hmsg, struct hv_kvp_msg *umsg)
356 {
357 	int utf_err = 0;
358 	uint32_t value_type;
359 	struct hv_kvp_ip_msg *host_ip_msg;
360 
361 	host_ip_msg = (struct hv_kvp_ip_msg*)hmsg;
362 	memset(umsg, 0, sizeof(struct hv_kvp_msg));
363 
364 	umsg->kvp_hdr.operation = hmsg->kvp_hdr.operation;
365 	umsg->kvp_hdr.pool = hmsg->kvp_hdr.pool;
366 
367 	switch (umsg->kvp_hdr.operation) {
368 	case HV_KVP_OP_SET_IP_INFO:
369 		hv_kvp_convert_utf16_ipinfo_to_utf8(host_ip_msg, umsg);
370 		break;
371 
372 	case HV_KVP_OP_GET_IP_INFO:
373 		utf16_to_utf8((char *)umsg->body.kvp_ip_val.adapter_id,
374 		    MAX_ADAPTER_ID_SIZE,
375 		    (uint16_t *)host_ip_msg->kvp_ip_val.adapter_id,
376 		    MAX_ADAPTER_ID_SIZE, 1, &utf_err);
377 
378 		umsg->body.kvp_ip_val.addr_family =
379 		    host_ip_msg->kvp_ip_val.addr_family;
380 		break;
381 
382 	case HV_KVP_OP_SET:
383 		value_type = hmsg->body.kvp_set.data.value_type;
384 
385 		switch (value_type) {
386 		case HV_REG_SZ:
387 			umsg->body.kvp_set.data.value_size =
388 			    utf16_to_utf8(
389 				(char *)umsg->body.kvp_set.data.msg_value.value,
390 				HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1,
391 				(uint16_t *)hmsg->body.kvp_set.data.msg_value.value,
392 				hmsg->body.kvp_set.data.value_size,
393 				1, &utf_err);
394 			/* utf8 encoding */
395 			umsg->body.kvp_set.data.value_size =
396 			    umsg->body.kvp_set.data.value_size / 2;
397 			break;
398 
399 		case HV_REG_U32:
400 			umsg->body.kvp_set.data.value_size =
401 			    sprintf(umsg->body.kvp_set.data.msg_value.value, "%d",
402 				hmsg->body.kvp_set.data.msg_value.value_u32) + 1;
403 			break;
404 
405 		case HV_REG_U64:
406 			umsg->body.kvp_set.data.value_size =
407 			    sprintf(umsg->body.kvp_set.data.msg_value.value, "%llu",
408 				(unsigned long long)
409 				hmsg->body.kvp_set.data.msg_value.value_u64) + 1;
410 			break;
411 		}
412 
413 		umsg->body.kvp_set.data.key_size =
414 		    utf16_to_utf8(
415 			umsg->body.kvp_set.data.key,
416 			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1,
417 			(uint16_t *)hmsg->body.kvp_set.data.key,
418 			hmsg->body.kvp_set.data.key_size,
419 			1, &utf_err);
420 
421 		/* utf8 encoding */
422 		umsg->body.kvp_set.data.key_size =
423 		    umsg->body.kvp_set.data.key_size / 2;
424 		break;
425 
426 	case HV_KVP_OP_GET:
427 		umsg->body.kvp_get.data.key_size =
428 		    utf16_to_utf8(umsg->body.kvp_get.data.key,
429 			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1,
430 			(uint16_t *)hmsg->body.kvp_get.data.key,
431 			hmsg->body.kvp_get.data.key_size,
432 			1, &utf_err);
433 		/* utf8 encoding */
434 		umsg->body.kvp_get.data.key_size =
435 		    umsg->body.kvp_get.data.key_size / 2;
436 		break;
437 
438 	case HV_KVP_OP_DELETE:
439 		umsg->body.kvp_delete.key_size =
440 		    utf16_to_utf8(umsg->body.kvp_delete.key,
441 			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1,
442 			(uint16_t *)hmsg->body.kvp_delete.key,
443 			hmsg->body.kvp_delete.key_size,
444 			1, &utf_err);
445 		/* utf8 encoding */
446 		umsg->body.kvp_delete.key_size =
447 		    umsg->body.kvp_delete.key_size / 2;
448 		break;
449 
450 	case HV_KVP_OP_ENUMERATE:
451 		umsg->body.kvp_enum_data.index =
452 		    hmsg->body.kvp_enum_data.index;
453 		break;
454 
455 	default:
456 		hv_kvp_log_info("%s: daemon_kvp_msg: Invalid operation : %d\n",
457 		    __func__, umsg->kvp_hdr.operation);
458 	}
459 }
460 
461 
462 /*
463  * Prepare a host kvp msg based on user kvp msg (utf8 to utf16)
464  */
465 static int
466 hv_kvp_convert_usermsg_to_hostmsg(struct hv_kvp_msg *umsg, struct hv_kvp_msg *hmsg)
467 {
468 	int hkey_len = 0, hvalue_len = 0, utf_err = 0;
469 	struct hv_kvp_exchg_msg_value *host_exchg_data;
470 	char *key_name, *value;
471 
472 	struct hv_kvp_ip_msg *host_ip_msg = (struct hv_kvp_ip_msg *)hmsg;
473 
474 	switch (hmsg->kvp_hdr.operation) {
475 	case HV_KVP_OP_GET_IP_INFO:
476 		return (hv_kvp_convert_utf8_ipinfo_to_utf16(umsg, host_ip_msg));
477 
478 	case HV_KVP_OP_SET_IP_INFO:
479 	case HV_KVP_OP_SET:
480 	case HV_KVP_OP_DELETE:
481 		return (0);
482 
483 	case HV_KVP_OP_ENUMERATE:
484 		host_exchg_data = &hmsg->body.kvp_enum_data.data;
485 		key_name = umsg->body.kvp_enum_data.data.key;
486 		hkey_len = utf8_to_utf16((uint16_t *)host_exchg_data->key,
487 				((HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2),
488 				key_name, strlen(key_name),
489 				1, &utf_err);
490 		/* utf16 encoding */
491 		host_exchg_data->key_size = 2 * (hkey_len + 1);
492 		value = umsg->body.kvp_enum_data.data.msg_value.value;
493 		hvalue_len = utf8_to_utf16(
494 				(uint16_t *)host_exchg_data->msg_value.value,
495 				((HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2),
496 				value, strlen(value),
497 				1, &utf_err);
498 		host_exchg_data->value_size = 2 * (hvalue_len + 1);
499 		host_exchg_data->value_type = HV_REG_SZ;
500 
501 		if ((hkey_len < 0) || (hvalue_len < 0))
502 			return (EINVAL);
503 
504 		return (0);
505 
506 	case HV_KVP_OP_GET:
507 		host_exchg_data = &hmsg->body.kvp_get.data;
508 		value = umsg->body.kvp_get.data.msg_value.value;
509 		hvalue_len = utf8_to_utf16(
510 				(uint16_t *)host_exchg_data->msg_value.value,
511 				((HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2),
512 				value, strlen(value),
513 				1, &utf_err);
514 		/* Convert value size to uft16 */
515 		host_exchg_data->value_size = 2 * (hvalue_len + 1);
516 		/* Use values by string */
517 		host_exchg_data->value_type = HV_REG_SZ;
518 
519 		if (hvalue_len < 0)
520 			return (EINVAL);
521 
522 		return (0);
523 
524 	default:
525 		return (EINVAL);
526 	}
527 }
528 
529 
530 /*
531  * Send the response back to the host.
532  */
533 static void
534 hv_kvp_respond_host(hv_kvp_sc *sc, uint32_t error)
535 {
536 	struct hv_vmbus_icmsg_hdr *hv_icmsg_hdrp;
537 
538 	hv_icmsg_hdrp = (struct hv_vmbus_icmsg_hdr *)
539 	    &sc->rcv_buf[sizeof(struct hv_vmbus_pipe_hdr)];
540 
541 	hv_icmsg_hdrp->status = error;
542 	hv_icmsg_hdrp->icflags = HV_ICMSGHDRFLAG_TRANSACTION |
543 	    HV_ICMSGHDRFLAG_RESPONSE;
544 
545 	error = vmbus_chan_send(vmbus_get_channel(sc->dev),
546 	    VMBUS_CHANPKT_TYPE_INBAND, 0, sc->rcv_buf, sc->host_msg_len,
547 	    sc->host_msg_id);
548 	if (error)
549 		hv_kvp_log_info("%s: hv_kvp_respond_host: sendpacket error:%d\n",
550 			__func__, error);
551 }
552 
553 
554 /*
555  * This is the main kvp kernel process that interacts with both user daemon
556  * and the host
557  */
558 static void
559 hv_kvp_send_msg_to_daemon(hv_kvp_sc *sc)
560 {
561 	struct hv_kvp_msg *hmsg = sc->host_kvp_msg;
562 	struct hv_kvp_msg *umsg = &sc->daemon_kvp_msg;
563 
564 	/* Prepare kvp_msg to be sent to user */
565 	hv_kvp_convert_hostmsg_to_usermsg(hmsg, umsg);
566 
567 	/* Send the msg to user via function deamon_read - setting sema */
568 	sema_post(&sc->dev_sema);
569 
570 	/* We should wake up the daemon, in case it's doing poll() */
571 	selwakeup(&sc->hv_kvp_selinfo);
572 }
573 
574 
575 /*
576  * Function to read the kvp request buffer from host
577  * and interact with daemon
578  */
579 static void
580 hv_kvp_process_request(void *context, int pending)
581 {
582 	uint8_t *kvp_buf;
583 	struct vmbus_channel *channel;
584 	uint32_t recvlen = 0;
585 	uint64_t requestid;
586 	struct hv_vmbus_icmsg_hdr *icmsghdrp;
587 	int ret = 0, error;
588 	hv_kvp_sc *sc;
589 
590 	hv_kvp_log_info("%s: entering hv_kvp_process_request\n", __func__);
591 
592 	sc = (hv_kvp_sc*)context;
593 	kvp_buf = sc->util_sc.ic_buf;
594 	channel = vmbus_get_channel(sc->dev);
595 
596 	recvlen = sc->util_sc.ic_buflen;
597 	ret = vmbus_chan_recv(channel, kvp_buf, &recvlen, &requestid);
598 	KASSERT(ret != ENOBUFS, ("hvkvp recvbuf is not large enough"));
599 	/* XXX check recvlen to make sure that it contains enough data */
600 
601 	while ((ret == 0) && (recvlen > 0)) {
602 		icmsghdrp = (struct hv_vmbus_icmsg_hdr *)
603 		    &kvp_buf[sizeof(struct hv_vmbus_pipe_hdr)];
604 
605 		hv_kvp_transaction_init(sc, recvlen, requestid, kvp_buf);
606 		if (icmsghdrp->icmsgtype == HV_ICMSGTYPE_NEGOTIATE) {
607 			error = vmbus_ic_negomsg(&sc->util_sc,
608 			    kvp_buf, &recvlen, KVP_FWVER, KVP_MSGVER);
609 			/* XXX handle vmbus_ic_negomsg failure. */
610 			if (!error)
611 				hv_kvp_respond_host(sc, HV_S_OK);
612 			else
613 				hv_kvp_respond_host(sc, HV_E_FAIL);
614 			/*
615 			 * It is ok to not acquire the mutex before setting
616 			 * req_in_progress here because negotiation is the
617 			 * first thing that happens and hence there is no
618 			 * chance of a race condition.
619 			 */
620 
621 			sc->req_in_progress = false;
622 			hv_kvp_log_info("%s :version negotiated\n", __func__);
623 
624 		} else {
625 			if (!sc->daemon_busy) {
626 
627 				hv_kvp_log_info("%s: issuing qury to daemon\n", __func__);
628 				mtx_lock(&sc->pending_mutex);
629 				sc->req_timed_out = false;
630 				sc->daemon_busy = true;
631 				mtx_unlock(&sc->pending_mutex);
632 
633 				hv_kvp_send_msg_to_daemon(sc);
634 				hv_kvp_log_info("%s: waiting for daemon\n", __func__);
635 			}
636 
637 			/* Wait 5 seconds for daemon to respond back */
638 			tsleep(sc, 0, "kvpworkitem", 5 * hz);
639 			hv_kvp_log_info("%s: came out of wait\n", __func__);
640 		}
641 
642 		mtx_lock(&sc->pending_mutex);
643 
644 		/* Notice that once req_timed_out is set to true
645 		 * it will remain true until the next request is
646 		 * sent to the daemon. The response from daemon
647 		 * is forwarded to host only when this flag is
648 		 * false.
649 		 */
650 		sc->req_timed_out = true;
651 
652 		/*
653 		 * Cancel request if so need be.
654 		 */
655 		if (hv_kvp_req_in_progress(sc)) {
656 			hv_kvp_log_info("%s: request was still active after wait so failing\n", __func__);
657 			hv_kvp_respond_host(sc, HV_E_FAIL);
658 			sc->req_in_progress = false;
659 		}
660 
661 		mtx_unlock(&sc->pending_mutex);
662 
663 		/*
664 		 * Try reading next buffer
665 		 */
666 		recvlen = sc->util_sc.ic_buflen;
667 		ret = vmbus_chan_recv(channel, kvp_buf, &recvlen, &requestid);
668 		KASSERT(ret != ENOBUFS, ("hvkvp recvbuf is not large enough"));
669 		/* XXX check recvlen to make sure that it contains enough data */
670 
671 		hv_kvp_log_info("%s: read: context %p, ret =%d, recvlen=%d\n",
672 			__func__, context, ret, recvlen);
673 	}
674 }
675 
676 
677 /*
678  * Callback routine that gets called whenever there is a message from host
679  */
680 static void
681 hv_kvp_callback(struct vmbus_channel *chan __unused, void *context)
682 {
683 	hv_kvp_sc *sc = (hv_kvp_sc*)context;
684 	/*
685 	 The first request from host will not be handled until daemon is registered.
686 	 when callback is triggered without a registered daemon, callback just return.
687 	 When a new daemon gets regsitered, this callbcak is trigged from _write op.
688 	*/
689 	if (sc->register_done) {
690 		hv_kvp_log_info("%s: Queuing work item\n", __func__);
691 		taskqueue_enqueue(taskqueue_thread, &sc->task);
692 	}
693 }
694 
695 static int
696 hv_kvp_dev_open(struct cdev *dev, int oflags, int devtype,
697 				struct thread *td)
698 {
699 	hv_kvp_sc *sc = (hv_kvp_sc*)dev->si_drv1;
700 
701 	hv_kvp_log_info("%s: Opened device \"hv_kvp_device\" successfully.\n", __func__);
702 	if (sc->dev_accessed)
703 		return (-EBUSY);
704 
705 	sc->daemon_task = curproc;
706 	sc->dev_accessed = true;
707 	sc->daemon_busy = false;
708 	return (0);
709 }
710 
711 
712 static int
713 hv_kvp_dev_close(struct cdev *dev __unused, int fflag __unused, int devtype __unused,
714 				 struct thread *td __unused)
715 {
716 	hv_kvp_sc *sc = (hv_kvp_sc*)dev->si_drv1;
717 
718 	hv_kvp_log_info("%s: Closing device \"hv_kvp_device\".\n", __func__);
719 	sc->dev_accessed = false;
720 	sc->register_done = false;
721 	return (0);
722 }
723 
724 
725 /*
726  * hv_kvp_daemon read invokes this function
727  * acts as a send to daemon
728  */
729 static int
730 hv_kvp_dev_daemon_read(struct cdev *dev, struct uio *uio, int ioflag __unused)
731 {
732 	size_t amt;
733 	int error = 0;
734 	struct hv_kvp_msg *hv_kvp_dev_buf;
735 	hv_kvp_sc *sc = (hv_kvp_sc*)dev->si_drv1;
736 
737 	/* Read is not allowed util registering is done. */
738 	if (!sc->register_done)
739 		return (EPERM);
740 
741 	sema_wait(&sc->dev_sema);
742 
743 	hv_kvp_dev_buf = malloc(sizeof(*hv_kvp_dev_buf), M_TEMP, M_WAITOK);
744 	memcpy(hv_kvp_dev_buf, &sc->daemon_kvp_msg, sizeof(struct hv_kvp_msg));
745 
746 	amt = MIN(uio->uio_resid, uio->uio_offset >= BUFFERSIZE + 1 ? 0 :
747 		BUFFERSIZE + 1 - uio->uio_offset);
748 
749 	if ((error = uiomove(hv_kvp_dev_buf, amt, uio)) != 0)
750 		hv_kvp_log_info("%s: hv_kvp uiomove read failed!\n", __func__);
751 
752 	free(hv_kvp_dev_buf, M_TEMP);
753 	return (error);
754 }
755 
756 
757 /*
758  * hv_kvp_daemon write invokes this function
759  * acts as a receive from daemon
760  */
761 static int
762 hv_kvp_dev_daemon_write(struct cdev *dev, struct uio *uio, int ioflag __unused)
763 {
764 	size_t amt;
765 	int error = 0;
766 	struct hv_kvp_msg *hv_kvp_dev_buf;
767 	hv_kvp_sc *sc = (hv_kvp_sc*)dev->si_drv1;
768 
769 	uio->uio_offset = 0;
770 	hv_kvp_dev_buf = malloc(sizeof(*hv_kvp_dev_buf), M_TEMP, M_WAITOK);
771 
772 	amt = MIN(uio->uio_resid, BUFFERSIZE);
773 	error = uiomove(hv_kvp_dev_buf, amt, uio);
774 
775 	if (error != 0) {
776 		free(hv_kvp_dev_buf, M_TEMP);
777 		return (error);
778 	}
779 	memcpy(&sc->daemon_kvp_msg, hv_kvp_dev_buf, sizeof(struct hv_kvp_msg));
780 
781 	free(hv_kvp_dev_buf, M_TEMP);
782 	if (sc->register_done == false) {
783 		if (sc->daemon_kvp_msg.kvp_hdr.operation == HV_KVP_OP_REGISTER) {
784 			sc->register_done = true;
785 			hv_kvp_callback(vmbus_get_channel(sc->dev), dev->si_drv1);
786 		}
787 		else {
788 			hv_kvp_log_info("%s, KVP Registration Failed\n", __func__);
789 			return (EINVAL);
790 		}
791 	} else {
792 
793 		mtx_lock(&sc->pending_mutex);
794 
795 		if(!sc->req_timed_out) {
796 			struct hv_kvp_msg *hmsg = sc->host_kvp_msg;
797 			struct hv_kvp_msg *umsg = &sc->daemon_kvp_msg;
798 
799 			error = hv_kvp_convert_usermsg_to_hostmsg(umsg, hmsg);
800 			hv_kvp_respond_host(sc, umsg->hdr.error);
801 			wakeup(sc);
802 			sc->req_in_progress = false;
803 			if (umsg->hdr.error != HV_S_OK)
804 				hv_kvp_log_info("%s, Error 0x%x from daemon\n",
805 				    __func__, umsg->hdr.error);
806 			if (error)
807 				hv_kvp_log_info("%s, Error from convert\n", __func__);
808 		}
809 
810 		sc->daemon_busy = false;
811 		mtx_unlock(&sc->pending_mutex);
812 	}
813 
814 	return (error);
815 }
816 
817 
818 /*
819  * hv_kvp_daemon poll invokes this function to check if data is available
820  * for daemon to read.
821  */
822 static int
823 hv_kvp_dev_daemon_poll(struct cdev *dev, int events, struct thread *td)
824 {
825 	int revents = 0;
826 	hv_kvp_sc *sc = (hv_kvp_sc*)dev->si_drv1;
827 
828 	mtx_lock(&sc->pending_mutex);
829 	/*
830 	 * We check global flag daemon_busy for the data availiability for
831 	 * userland to read. Deamon_busy is set to true before driver has data
832 	 * for daemon to read. It is set to false after daemon sends
833 	 * then response back to driver.
834 	 */
835 	if (sc->daemon_busy == true)
836 		revents = POLLIN;
837 	else
838 		selrecord(td, &sc->hv_kvp_selinfo);
839 
840 	mtx_unlock(&sc->pending_mutex);
841 
842 	return (revents);
843 }
844 
845 static int
846 hv_kvp_probe(device_t dev)
847 {
848 
849 	return (vmbus_ic_probe(dev, vmbus_kvp_descs));
850 }
851 
852 static int
853 hv_kvp_attach(device_t dev)
854 {
855 	int error;
856 	struct sysctl_oid_list *child;
857 	struct sysctl_ctx_list *ctx;
858 
859 	hv_kvp_sc *sc = (hv_kvp_sc*)device_get_softc(dev);
860 
861 	sc->dev = dev;
862 	sema_init(&sc->dev_sema, 0, "hv_kvp device semaphore");
863 	mtx_init(&sc->pending_mutex, "hv-kvp pending mutex",
864 		NULL, MTX_DEF);
865 
866 	ctx = device_get_sysctl_ctx(dev);
867 	child = SYSCTL_CHILDREN(device_get_sysctl_tree(dev));
868 
869 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "hv_kvp_log",
870 	    CTLFLAG_RWTUN, &hv_kvp_log, 0, "Hyperv KVP service log level");
871 
872 	TASK_INIT(&sc->task, 0, hv_kvp_process_request, sc);
873 
874 	/* create character device */
875 	error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
876 			&sc->hv_kvp_dev,
877 			&hv_kvp_cdevsw,
878 			0,
879 			UID_ROOT,
880 			GID_WHEEL,
881 			0640,
882 			"hv_kvp_dev");
883 
884 	if (error != 0)
885 		return (error);
886 	sc->hv_kvp_dev->si_drv1 = sc;
887 
888 	return (vmbus_ic_attach(dev, hv_kvp_callback));
889 }
890 
891 static int
892 hv_kvp_detach(device_t dev)
893 {
894 	hv_kvp_sc *sc = (hv_kvp_sc*)device_get_softc(dev);
895 
896 	if (sc->daemon_task != NULL) {
897 		PROC_LOCK(sc->daemon_task);
898 		kern_psignal(sc->daemon_task, SIGKILL);
899 		PROC_UNLOCK(sc->daemon_task);
900 	}
901 
902 	destroy_dev(sc->hv_kvp_dev);
903 	return (vmbus_ic_detach(dev));
904 }
905 
906 static device_method_t kvp_methods[] = {
907 	/* Device interface */
908 	DEVMETHOD(device_probe, hv_kvp_probe),
909 	DEVMETHOD(device_attach, hv_kvp_attach),
910 	DEVMETHOD(device_detach, hv_kvp_detach),
911 	{ 0, 0 }
912 };
913 
914 static driver_t kvp_driver = { "hvkvp", kvp_methods, sizeof(hv_kvp_sc)};
915 
916 DRIVER_MODULE(hv_kvp, vmbus, kvp_driver, NULL, NULL);
917 MODULE_VERSION(hv_kvp, 1);
918 MODULE_DEPEND(hv_kvp, vmbus, 1, 1, 1);
919