xref: /freebsd/sys/dev/hyperv/utilities/hv_kvp.c (revision 1c4f5adba92947a5faa1836449a621502a1678b8)
1 /*-
2  * Copyright (c) 2014,2016 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/signal.h>
58 #include <sys/syslog.h>
59 #include <sys/systm.h>
60 #include <sys/mutex.h>
61 
62 #include <net/if.h>
63 #include <net/if_arp.h>
64 #include <net/if_var.h>
65 
66 #include <dev/hyperv/include/hyperv.h>
67 #include <dev/hyperv/netvsc/hv_net_vsc.h>
68 
69 #include "hv_util.h"
70 #include "unicode.h"
71 #include "hv_kvp.h"
72 #include "vmbus_if.h"
73 
74 /* hv_kvp defines */
75 #define BUFFERSIZE	sizeof(struct hv_kvp_msg)
76 #define KVP_SUCCESS	0
77 #define KVP_ERROR	1
78 #define kvp_hdr		hdr.kvp_hdr
79 
80 /* hv_kvp debug control */
81 static int hv_kvp_log = 0;
82 
83 #define	hv_kvp_log_error(...)	do {				\
84 	if (hv_kvp_log > 0)				\
85 		log(LOG_ERR, "hv_kvp: " __VA_ARGS__);	\
86 } while (0)
87 
88 #define	hv_kvp_log_info(...) do {				\
89 	if (hv_kvp_log > 1)				\
90 		log(LOG_INFO, "hv_kvp: " __VA_ARGS__);		\
91 } while (0)
92 
93 static const struct hyperv_guid service_guid = { .hv_guid =
94 	{0xe7, 0xf4, 0xa0, 0xa9, 0x45, 0x5a, 0x96, 0x4d,
95 	0xb8, 0x27, 0x8a, 0x84, 0x1e, 0x8c, 0x3,  0xe6} };
96 
97 /* character device prototypes */
98 static d_open_t		hv_kvp_dev_open;
99 static d_close_t	hv_kvp_dev_close;
100 static d_read_t		hv_kvp_dev_daemon_read;
101 static d_write_t	hv_kvp_dev_daemon_write;
102 static d_poll_t		hv_kvp_dev_daemon_poll;
103 
104 /* hv_kvp character device structure */
105 static struct cdevsw hv_kvp_cdevsw =
106 {
107 	.d_version	= D_VERSION,
108 	.d_open		= hv_kvp_dev_open,
109 	.d_close	= hv_kvp_dev_close,
110 	.d_read		= hv_kvp_dev_daemon_read,
111 	.d_write	= hv_kvp_dev_daemon_write,
112 	.d_poll		= hv_kvp_dev_daemon_poll,
113 	.d_name		= "hv_kvp_dev",
114 };
115 
116 
117 /*
118  * Global state to track and synchronize multiple
119  * KVP transaction requests from the host.
120  */
121 typedef struct hv_kvp_sc {
122 	struct hv_util_sc	util_sc;
123 
124 	/* Unless specified the pending mutex should be
125 	 * used to alter the values of the following parameters:
126 	 * 1. req_in_progress
127 	 * 2. req_timed_out
128 	 */
129 	struct mtx		pending_mutex;
130 
131 	struct task		task;
132 
133 	/* To track if transaction is active or not */
134 	boolean_t		req_in_progress;
135 	/* Tracks if daemon did not reply back in time */
136 	boolean_t		req_timed_out;
137 	/* Tracks if daemon is serving a request currently */
138 	boolean_t		daemon_busy;
139 
140 	/* Length of host message */
141 	uint32_t		host_msg_len;
142 
143 	/* Host message id */
144 	uint64_t		host_msg_id;
145 
146 	/* Current kvp message from the host */
147 	struct hv_kvp_msg	*host_kvp_msg;
148 
149 	 /* Current kvp message for daemon */
150 	struct hv_kvp_msg	daemon_kvp_msg;
151 
152 	/* Rcv buffer for communicating with the host*/
153 	uint8_t			*rcv_buf;
154 
155 	/* Device semaphore to control communication */
156 	struct sema		dev_sema;
157 
158 	/* Indicates if daemon registered with driver */
159 	boolean_t		register_done;
160 
161 	/* Character device status */
162 	boolean_t		dev_accessed;
163 
164 	struct cdev *hv_kvp_dev;
165 
166 	struct proc *daemon_task;
167 
168 	struct selinfo hv_kvp_selinfo;
169 } hv_kvp_sc;
170 
171 /* hv_kvp prototypes */
172 static int	hv_kvp_req_in_progress(hv_kvp_sc *sc);
173 static void	hv_kvp_transaction_init(hv_kvp_sc *sc, uint32_t, uint64_t, uint8_t *);
174 static void	hv_kvp_send_msg_to_daemon(hv_kvp_sc *sc);
175 static void	hv_kvp_process_request(void *context, int pending);
176 
177 /*
178  * hv_kvp low level functions
179  */
180 
181 /*
182  * Check if kvp transaction is in progres
183  */
184 static int
185 hv_kvp_req_in_progress(hv_kvp_sc *sc)
186 {
187 
188 	return (sc->req_in_progress);
189 }
190 
191 
192 /*
193  * This routine is called whenever a message is received from the host
194  */
195 static void
196 hv_kvp_transaction_init(hv_kvp_sc *sc, uint32_t rcv_len,
197 			uint64_t request_id, uint8_t *rcv_buf)
198 {
199 
200 	/* Store all the relevant message details in the global structure */
201 	/* Do not need to use mutex for req_in_progress here */
202 	sc->req_in_progress = true;
203 	sc->host_msg_len = rcv_len;
204 	sc->host_msg_id = request_id;
205 	sc->rcv_buf = rcv_buf;
206 	sc->host_kvp_msg = (struct hv_kvp_msg *)&rcv_buf[
207 		sizeof(struct hv_vmbus_pipe_hdr) +
208 		sizeof(struct hv_vmbus_icmsg_hdr)];
209 }
210 
211 
212 /*
213  * hv_kvp - version neogtiation function
214  */
215 static void
216 hv_kvp_negotiate_version(struct hv_vmbus_icmsg_hdr *icmsghdrp,
217 			 struct hv_vmbus_icmsg_negotiate *negop,
218 			 uint8_t *buf)
219 {
220 	int icframe_vercnt;
221 	int icmsg_vercnt;
222 
223 	icmsghdrp->icmsgsize = 0x10;
224 
225 	negop = (struct hv_vmbus_icmsg_negotiate *)&buf[
226 		sizeof(struct hv_vmbus_pipe_hdr) +
227 		sizeof(struct hv_vmbus_icmsg_hdr)];
228 	icframe_vercnt = negop->icframe_vercnt;
229 	icmsg_vercnt = negop->icmsg_vercnt;
230 
231 	/*
232 	 * Select the framework version number we will support
233 	 */
234 	if ((icframe_vercnt >= 2) && (negop->icversion_data[1].major == 3)) {
235 		icframe_vercnt = 3;
236 		if (icmsg_vercnt > 2)
237 			icmsg_vercnt = 4;
238 		else
239 			icmsg_vercnt = 3;
240 	} else {
241 		icframe_vercnt = 1;
242 		icmsg_vercnt = 1;
243 	}
244 
245 	negop->icframe_vercnt = 1;
246 	negop->icmsg_vercnt = 1;
247 	negop->icversion_data[0].major = icframe_vercnt;
248 	negop->icversion_data[0].minor = 0;
249 	negop->icversion_data[1].major = icmsg_vercnt;
250 	negop->icversion_data[1].minor = 0;
251 }
252 
253 
254 /*
255  * Convert ip related info in umsg from utf8 to utf16 and store in hmsg
256  */
257 static int
258 hv_kvp_convert_utf8_ipinfo_to_utf16(struct hv_kvp_msg *umsg,
259 				    struct hv_kvp_ip_msg *host_ip_msg)
260 {
261 	int err_ip, err_subnet, err_gway, err_dns, err_adap;
262 	int UNUSED_FLAG = 1;
263 
264 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.ip_addr,
265 	    MAX_IP_ADDR_SIZE,
266 	    (char *)umsg->body.kvp_ip_val.ip_addr,
267 	    strlen((char *)umsg->body.kvp_ip_val.ip_addr),
268 	    UNUSED_FLAG,
269 	    &err_ip);
270 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.sub_net,
271 	    MAX_IP_ADDR_SIZE,
272 	    (char *)umsg->body.kvp_ip_val.sub_net,
273 	    strlen((char *)umsg->body.kvp_ip_val.sub_net),
274 	    UNUSED_FLAG,
275 	    &err_subnet);
276 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.gate_way,
277 	    MAX_GATEWAY_SIZE,
278 	    (char *)umsg->body.kvp_ip_val.gate_way,
279 	    strlen((char *)umsg->body.kvp_ip_val.gate_way),
280 	    UNUSED_FLAG,
281 	    &err_gway);
282 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.dns_addr,
283 	    MAX_IP_ADDR_SIZE,
284 	    (char *)umsg->body.kvp_ip_val.dns_addr,
285 	    strlen((char *)umsg->body.kvp_ip_val.dns_addr),
286 	    UNUSED_FLAG,
287 	    &err_dns);
288 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.adapter_id,
289 	    MAX_IP_ADDR_SIZE,
290 	    (char *)umsg->body.kvp_ip_val.adapter_id,
291 	    strlen((char *)umsg->body.kvp_ip_val.adapter_id),
292 	    UNUSED_FLAG,
293 	    &err_adap);
294 
295 	host_ip_msg->kvp_ip_val.dhcp_enabled = umsg->body.kvp_ip_val.dhcp_enabled;
296 	host_ip_msg->kvp_ip_val.addr_family = umsg->body.kvp_ip_val.addr_family;
297 
298 	return (err_ip | err_subnet | err_gway | err_dns | err_adap);
299 }
300 
301 
302 /*
303  * Convert ip related info in hmsg from utf16 to utf8 and store in umsg
304  */
305 static int
306 hv_kvp_convert_utf16_ipinfo_to_utf8(struct hv_kvp_ip_msg *host_ip_msg,
307 				    struct hv_kvp_msg *umsg)
308 {
309 	int err_ip, err_subnet, err_gway, err_dns, err_adap;
310 	int UNUSED_FLAG = 1;
311 	device_t *devs;
312 	int devcnt;
313 
314 	/* IP Address */
315 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.ip_addr,
316 	    MAX_IP_ADDR_SIZE,
317 	    (uint16_t *)host_ip_msg->kvp_ip_val.ip_addr,
318 	    MAX_IP_ADDR_SIZE,
319 	    UNUSED_FLAG,
320 	    &err_ip);
321 
322 	/* Adapter ID : GUID */
323 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.adapter_id,
324 	    MAX_ADAPTER_ID_SIZE,
325 	    (uint16_t *)host_ip_msg->kvp_ip_val.adapter_id,
326 	    MAX_ADAPTER_ID_SIZE,
327 	    UNUSED_FLAG,
328 	    &err_adap);
329 
330 	if (devclass_get_devices(devclass_find("hn"), &devs, &devcnt) == 0) {
331 		for (devcnt = devcnt - 1; devcnt >= 0; devcnt--) {
332 			/* XXX access other driver's softc?  are you kidding? */
333 			device_t dev = devs[devcnt];
334 			struct hn_softc *sc = device_get_softc(dev);
335 			struct hv_vmbus_channel *chan;
336 			char buf[HYPERV_GUID_STRLEN];
337 
338 			/*
339 			 * Trying to find GUID of Network Device
340 			 * TODO: need vmbus interface.
341 			 */
342 			chan = vmbus_get_channel(dev);
343 			hyperv_guid2str(&chan->ch_guid_inst, buf, sizeof(buf));
344 
345 			if (strncmp(buf, (char *)umsg->body.kvp_ip_val.adapter_id,
346 			    HYPERV_GUID_STRLEN - 1) == 0) {
347 				strlcpy((char *)umsg->body.kvp_ip_val.adapter_id,
348 				    sc->hn_ifp->if_xname, MAX_ADAPTER_ID_SIZE);
349 				break;
350 			}
351 		}
352 		free(devs, M_TEMP);
353 	}
354 
355 	/* Address Family , DHCP , SUBNET, Gateway, DNS */
356 	umsg->kvp_hdr.operation = host_ip_msg->operation;
357 	umsg->body.kvp_ip_val.addr_family = host_ip_msg->kvp_ip_val.addr_family;
358 	umsg->body.kvp_ip_val.dhcp_enabled = host_ip_msg->kvp_ip_val.dhcp_enabled;
359 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.sub_net, MAX_IP_ADDR_SIZE,
360 	    (uint16_t *)host_ip_msg->kvp_ip_val.sub_net,
361 	    MAX_IP_ADDR_SIZE,
362 	    UNUSED_FLAG,
363 	    &err_subnet);
364 
365 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.gate_way, MAX_GATEWAY_SIZE,
366 	    (uint16_t *)host_ip_msg->kvp_ip_val.gate_way,
367 	    MAX_GATEWAY_SIZE,
368 	    UNUSED_FLAG,
369 	    &err_gway);
370 
371 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.dns_addr, MAX_IP_ADDR_SIZE,
372 	    (uint16_t *)host_ip_msg->kvp_ip_val.dns_addr,
373 	    MAX_IP_ADDR_SIZE,
374 	    UNUSED_FLAG,
375 	    &err_dns);
376 
377 	return (err_ip | err_subnet | err_gway | err_dns | err_adap);
378 }
379 
380 
381 /*
382  * Prepare a user kvp msg based on host kvp msg (utf16 to utf8)
383  * Ensure utf16_utf8 takes care of the additional string terminating char!!
384  */
385 static void
386 hv_kvp_convert_hostmsg_to_usermsg(struct hv_kvp_msg *hmsg, struct hv_kvp_msg *umsg)
387 {
388 	int utf_err = 0;
389 	uint32_t value_type;
390 	struct hv_kvp_ip_msg *host_ip_msg;
391 
392 	host_ip_msg = (struct hv_kvp_ip_msg*)hmsg;
393 	memset(umsg, 0, sizeof(struct hv_kvp_msg));
394 
395 	umsg->kvp_hdr.operation = hmsg->kvp_hdr.operation;
396 	umsg->kvp_hdr.pool = hmsg->kvp_hdr.pool;
397 
398 	switch (umsg->kvp_hdr.operation) {
399 	case HV_KVP_OP_SET_IP_INFO:
400 		hv_kvp_convert_utf16_ipinfo_to_utf8(host_ip_msg, umsg);
401 		break;
402 
403 	case HV_KVP_OP_GET_IP_INFO:
404 		utf16_to_utf8((char *)umsg->body.kvp_ip_val.adapter_id,
405 		    MAX_ADAPTER_ID_SIZE,
406 		    (uint16_t *)host_ip_msg->kvp_ip_val.adapter_id,
407 		    MAX_ADAPTER_ID_SIZE, 1, &utf_err);
408 
409 		umsg->body.kvp_ip_val.addr_family =
410 		    host_ip_msg->kvp_ip_val.addr_family;
411 		break;
412 
413 	case HV_KVP_OP_SET:
414 		value_type = hmsg->body.kvp_set.data.value_type;
415 
416 		switch (value_type) {
417 		case HV_REG_SZ:
418 			umsg->body.kvp_set.data.value_size =
419 			    utf16_to_utf8(
420 				(char *)umsg->body.kvp_set.data.msg_value.value,
421 				HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1,
422 				(uint16_t *)hmsg->body.kvp_set.data.msg_value.value,
423 				hmsg->body.kvp_set.data.value_size,
424 				1, &utf_err);
425 			/* utf8 encoding */
426 			umsg->body.kvp_set.data.value_size =
427 			    umsg->body.kvp_set.data.value_size / 2;
428 			break;
429 
430 		case HV_REG_U32:
431 			umsg->body.kvp_set.data.value_size =
432 			    sprintf(umsg->body.kvp_set.data.msg_value.value, "%d",
433 				hmsg->body.kvp_set.data.msg_value.value_u32) + 1;
434 			break;
435 
436 		case HV_REG_U64:
437 			umsg->body.kvp_set.data.value_size =
438 			    sprintf(umsg->body.kvp_set.data.msg_value.value, "%llu",
439 				(unsigned long long)
440 				hmsg->body.kvp_set.data.msg_value.value_u64) + 1;
441 			break;
442 		}
443 
444 		umsg->body.kvp_set.data.key_size =
445 		    utf16_to_utf8(
446 			umsg->body.kvp_set.data.key,
447 			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1,
448 			(uint16_t *)hmsg->body.kvp_set.data.key,
449 			hmsg->body.kvp_set.data.key_size,
450 			1, &utf_err);
451 
452 		/* utf8 encoding */
453 		umsg->body.kvp_set.data.key_size =
454 		    umsg->body.kvp_set.data.key_size / 2;
455 		break;
456 
457 	case HV_KVP_OP_GET:
458 		umsg->body.kvp_get.data.key_size =
459 		    utf16_to_utf8(umsg->body.kvp_get.data.key,
460 			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1,
461 			(uint16_t *)hmsg->body.kvp_get.data.key,
462 			hmsg->body.kvp_get.data.key_size,
463 			1, &utf_err);
464 		/* utf8 encoding */
465 		umsg->body.kvp_get.data.key_size =
466 		    umsg->body.kvp_get.data.key_size / 2;
467 		break;
468 
469 	case HV_KVP_OP_DELETE:
470 		umsg->body.kvp_delete.key_size =
471 		    utf16_to_utf8(umsg->body.kvp_delete.key,
472 			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1,
473 			(uint16_t *)hmsg->body.kvp_delete.key,
474 			hmsg->body.kvp_delete.key_size,
475 			1, &utf_err);
476 		/* utf8 encoding */
477 		umsg->body.kvp_delete.key_size =
478 		    umsg->body.kvp_delete.key_size / 2;
479 		break;
480 
481 	case HV_KVP_OP_ENUMERATE:
482 		umsg->body.kvp_enum_data.index =
483 		    hmsg->body.kvp_enum_data.index;
484 		break;
485 
486 	default:
487 		hv_kvp_log_info("%s: daemon_kvp_msg: Invalid operation : %d\n",
488 		    __func__, umsg->kvp_hdr.operation);
489 	}
490 }
491 
492 
493 /*
494  * Prepare a host kvp msg based on user kvp msg (utf8 to utf16)
495  */
496 static int
497 hv_kvp_convert_usermsg_to_hostmsg(struct hv_kvp_msg *umsg, struct hv_kvp_msg *hmsg)
498 {
499 	int hkey_len = 0, hvalue_len = 0, utf_err = 0;
500 	struct hv_kvp_exchg_msg_value *host_exchg_data;
501 	char *key_name, *value;
502 
503 	struct hv_kvp_ip_msg *host_ip_msg = (struct hv_kvp_ip_msg *)hmsg;
504 
505 	switch (hmsg->kvp_hdr.operation) {
506 	case HV_KVP_OP_GET_IP_INFO:
507 		return (hv_kvp_convert_utf8_ipinfo_to_utf16(umsg, host_ip_msg));
508 
509 	case HV_KVP_OP_SET_IP_INFO:
510 	case HV_KVP_OP_SET:
511 	case HV_KVP_OP_DELETE:
512 		return (KVP_SUCCESS);
513 
514 	case HV_KVP_OP_ENUMERATE:
515 		host_exchg_data = &hmsg->body.kvp_enum_data.data;
516 		key_name = umsg->body.kvp_enum_data.data.key;
517 		hkey_len = utf8_to_utf16((uint16_t *)host_exchg_data->key,
518 				((HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2),
519 				key_name, strlen(key_name),
520 				1, &utf_err);
521 		/* utf16 encoding */
522 		host_exchg_data->key_size = 2 * (hkey_len + 1);
523 		value = umsg->body.kvp_enum_data.data.msg_value.value;
524 		hvalue_len = utf8_to_utf16(
525 				(uint16_t *)host_exchg_data->msg_value.value,
526 				((HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2),
527 				value, strlen(value),
528 				1, &utf_err);
529 		host_exchg_data->value_size = 2 * (hvalue_len + 1);
530 		host_exchg_data->value_type = HV_REG_SZ;
531 
532 		if ((hkey_len < 0) || (hvalue_len < 0))
533 			return (HV_KVP_E_FAIL);
534 
535 		return (KVP_SUCCESS);
536 
537 	case HV_KVP_OP_GET:
538 		host_exchg_data = &hmsg->body.kvp_get.data;
539 		value = umsg->body.kvp_get.data.msg_value.value;
540 		hvalue_len = utf8_to_utf16(
541 				(uint16_t *)host_exchg_data->msg_value.value,
542 				((HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2),
543 				value, strlen(value),
544 				1, &utf_err);
545 		/* Convert value size to uft16 */
546 		host_exchg_data->value_size = 2 * (hvalue_len + 1);
547 		/* Use values by string */
548 		host_exchg_data->value_type = HV_REG_SZ;
549 
550 		if ((hkey_len < 0) || (hvalue_len < 0))
551 			return (HV_KVP_E_FAIL);
552 
553 		return (KVP_SUCCESS);
554 
555 	default:
556 		return (HV_KVP_E_FAIL);
557 	}
558 }
559 
560 
561 /*
562  * Send the response back to the host.
563  */
564 static void
565 hv_kvp_respond_host(hv_kvp_sc *sc, int error)
566 {
567 	struct hv_vmbus_icmsg_hdr *hv_icmsg_hdrp;
568 
569 	hv_icmsg_hdrp = (struct hv_vmbus_icmsg_hdr *)
570 	    &sc->rcv_buf[sizeof(struct hv_vmbus_pipe_hdr)];
571 
572 	if (error)
573 		error = HV_KVP_E_FAIL;
574 
575 	hv_icmsg_hdrp->status = error;
576 	hv_icmsg_hdrp->icflags = HV_ICMSGHDRFLAG_TRANSACTION | HV_ICMSGHDRFLAG_RESPONSE;
577 
578 	error = hv_vmbus_channel_send_packet(sc->util_sc.channel,
579 			sc->rcv_buf,
580 			sc->host_msg_len, sc->host_msg_id,
581 			HV_VMBUS_PACKET_TYPE_DATA_IN_BAND, 0);
582 
583 	if (error)
584 		hv_kvp_log_info("%s: hv_kvp_respond_host: sendpacket error:%d\n",
585 			__func__, error);
586 }
587 
588 
589 /*
590  * This is the main kvp kernel process that interacts with both user daemon
591  * and the host
592  */
593 static void
594 hv_kvp_send_msg_to_daemon(hv_kvp_sc *sc)
595 {
596 	struct hv_kvp_msg *hmsg = sc->host_kvp_msg;
597 	struct hv_kvp_msg *umsg = &sc->daemon_kvp_msg;
598 
599 	/* Prepare kvp_msg to be sent to user */
600 	hv_kvp_convert_hostmsg_to_usermsg(hmsg, umsg);
601 
602 	/* Send the msg to user via function deamon_read - setting sema */
603 	sema_post(&sc->dev_sema);
604 
605 	/* We should wake up the daemon, in case it's doing poll() */
606 	selwakeup(&sc->hv_kvp_selinfo);
607 }
608 
609 
610 /*
611  * Function to read the kvp request buffer from host
612  * and interact with daemon
613  */
614 static void
615 hv_kvp_process_request(void *context, int pending)
616 {
617 	uint8_t *kvp_buf;
618 	hv_vmbus_channel *channel;
619 	uint32_t recvlen = 0;
620 	uint64_t requestid;
621 	struct hv_vmbus_icmsg_hdr *icmsghdrp;
622 	int ret = 0;
623 	hv_kvp_sc		*sc;
624 
625 	hv_kvp_log_info("%s: entering hv_kvp_process_request\n", __func__);
626 
627 	sc = (hv_kvp_sc*)context;
628 	kvp_buf = sc->util_sc.receive_buffer;
629 	channel = sc->util_sc.channel;
630 
631 	ret = hv_vmbus_channel_recv_packet(channel, kvp_buf, 2 * PAGE_SIZE,
632 		&recvlen, &requestid);
633 
634 	while ((ret == 0) && (recvlen > 0)) {
635 
636 		icmsghdrp = (struct hv_vmbus_icmsg_hdr *)
637 			&kvp_buf[sizeof(struct hv_vmbus_pipe_hdr)];
638 
639 		hv_kvp_transaction_init(sc, recvlen, requestid, kvp_buf);
640 		if (icmsghdrp->icmsgtype == HV_ICMSGTYPE_NEGOTIATE) {
641 			hv_kvp_negotiate_version(icmsghdrp, NULL, kvp_buf);
642 			hv_kvp_respond_host(sc, ret);
643 
644 			/*
645 			 * It is ok to not acquire the mutex before setting
646 			 * req_in_progress here because negotiation is the
647 			 * first thing that happens and hence there is no
648 			 * chance of a race condition.
649 			 */
650 
651 			sc->req_in_progress = false;
652 			hv_kvp_log_info("%s :version negotiated\n", __func__);
653 
654 		} else {
655 			if (!sc->daemon_busy) {
656 
657 				hv_kvp_log_info("%s: issuing qury to daemon\n", __func__);
658 				mtx_lock(&sc->pending_mutex);
659 				sc->req_timed_out = false;
660 				sc->daemon_busy = true;
661 				mtx_unlock(&sc->pending_mutex);
662 
663 				hv_kvp_send_msg_to_daemon(sc);
664 				hv_kvp_log_info("%s: waiting for daemon\n", __func__);
665 			}
666 
667 			/* Wait 5 seconds for daemon to respond back */
668 			tsleep(sc, 0, "kvpworkitem", 5 * hz);
669 			hv_kvp_log_info("%s: came out of wait\n", __func__);
670 		}
671 
672 		mtx_lock(&sc->pending_mutex);
673 
674 		/* Notice that once req_timed_out is set to true
675 		 * it will remain true until the next request is
676 		 * sent to the daemon. The response from daemon
677 		 * is forwarded to host only when this flag is
678 		 * false.
679 		 */
680 		sc->req_timed_out = true;
681 
682 		/*
683 		 * Cancel request if so need be.
684 		 */
685 		if (hv_kvp_req_in_progress(sc)) {
686 			hv_kvp_log_info("%s: request was still active after wait so failing\n", __func__);
687 			hv_kvp_respond_host(sc, HV_KVP_E_FAIL);
688 			sc->req_in_progress = false;
689 		}
690 
691 		mtx_unlock(&sc->pending_mutex);
692 
693 		/*
694 		 * Try reading next buffer
695 		 */
696 		recvlen = 0;
697 		ret = hv_vmbus_channel_recv_packet(channel, kvp_buf, 2 * PAGE_SIZE,
698 			&recvlen, &requestid);
699 		hv_kvp_log_info("%s: read: context %p, ret =%d, recvlen=%d\n",
700 			__func__, context, ret, recvlen);
701 	}
702 }
703 
704 
705 /*
706  * Callback routine that gets called whenever there is a message from host
707  */
708 static void
709 hv_kvp_callback(void *context)
710 {
711 	hv_kvp_sc *sc = (hv_kvp_sc*)context;
712 	/*
713 	 The first request from host will not be handled until daemon is registered.
714 	 when callback is triggered without a registered daemon, callback just return.
715 	 When a new daemon gets regsitered, this callbcak is trigged from _write op.
716 	*/
717 	if (sc->register_done) {
718 		hv_kvp_log_info("%s: Queuing work item\n", __func__);
719 		taskqueue_enqueue(taskqueue_thread, &sc->task);
720 	}
721 }
722 
723 static int
724 hv_kvp_dev_open(struct cdev *dev, int oflags, int devtype,
725 				struct thread *td)
726 {
727 	hv_kvp_sc *sc = (hv_kvp_sc*)dev->si_drv1;
728 
729 	hv_kvp_log_info("%s: Opened device \"hv_kvp_device\" successfully.\n", __func__);
730 	if (sc->dev_accessed)
731 		return (-EBUSY);
732 
733 	sc->daemon_task = curproc;
734 	sc->dev_accessed = true;
735 	sc->daemon_busy = false;
736 	return (0);
737 }
738 
739 
740 static int
741 hv_kvp_dev_close(struct cdev *dev __unused, int fflag __unused, int devtype __unused,
742 				 struct thread *td __unused)
743 {
744 	hv_kvp_sc *sc = (hv_kvp_sc*)dev->si_drv1;
745 
746 	hv_kvp_log_info("%s: Closing device \"hv_kvp_device\".\n", __func__);
747 	sc->dev_accessed = false;
748 	sc->register_done = false;
749 	return (0);
750 }
751 
752 
753 /*
754  * hv_kvp_daemon read invokes this function
755  * acts as a send to daemon
756  */
757 static int
758 hv_kvp_dev_daemon_read(struct cdev *dev, struct uio *uio, int ioflag __unused)
759 {
760 	size_t amt;
761 	int error = 0;
762 	struct hv_kvp_msg *hv_kvp_dev_buf;
763 	hv_kvp_sc *sc = (hv_kvp_sc*)dev->si_drv1;
764 
765 	/* Check hv_kvp daemon registration status*/
766 	if (!sc->register_done)
767 		return (KVP_ERROR);
768 
769 	sema_wait(&sc->dev_sema);
770 
771 	hv_kvp_dev_buf = malloc(sizeof(*hv_kvp_dev_buf), M_TEMP, M_WAITOK);
772 	memcpy(hv_kvp_dev_buf, &sc->daemon_kvp_msg, sizeof(struct hv_kvp_msg));
773 
774 	amt = MIN(uio->uio_resid, uio->uio_offset >= BUFFERSIZE + 1 ? 0 :
775 		BUFFERSIZE + 1 - uio->uio_offset);
776 
777 	if ((error = uiomove(hv_kvp_dev_buf, amt, uio)) != 0)
778 		hv_kvp_log_info("%s: hv_kvp uiomove read failed!\n", __func__);
779 
780 	free(hv_kvp_dev_buf, M_TEMP);
781 	return (error);
782 }
783 
784 
785 /*
786  * hv_kvp_daemon write invokes this function
787  * acts as a receive from daemon
788  */
789 static int
790 hv_kvp_dev_daemon_write(struct cdev *dev, struct uio *uio, int ioflag __unused)
791 {
792 	size_t amt;
793 	int error = 0;
794 	struct hv_kvp_msg *hv_kvp_dev_buf;
795 	hv_kvp_sc *sc = (hv_kvp_sc*)dev->si_drv1;
796 
797 	uio->uio_offset = 0;
798 	hv_kvp_dev_buf = malloc(sizeof(*hv_kvp_dev_buf), M_TEMP, M_WAITOK);
799 
800 	amt = MIN(uio->uio_resid, BUFFERSIZE);
801 	error = uiomove(hv_kvp_dev_buf, amt, uio);
802 
803 	if (error != 0) {
804 		free(hv_kvp_dev_buf, M_TEMP);
805 		return (error);
806 	}
807 	memcpy(&sc->daemon_kvp_msg, hv_kvp_dev_buf, sizeof(struct hv_kvp_msg));
808 
809 	free(hv_kvp_dev_buf, M_TEMP);
810 	if (sc->register_done == false) {
811 		if (sc->daemon_kvp_msg.kvp_hdr.operation == HV_KVP_OP_REGISTER) {
812 			sc->register_done = true;
813 			hv_kvp_callback(dev->si_drv1);
814 		}
815 		else {
816 			hv_kvp_log_info("%s, KVP Registration Failed\n", __func__);
817 			return (KVP_ERROR);
818 		}
819 	} else {
820 
821 		mtx_lock(&sc->pending_mutex);
822 
823 		if(!sc->req_timed_out) {
824 			struct hv_kvp_msg *hmsg = sc->host_kvp_msg;
825 			struct hv_kvp_msg *umsg = &sc->daemon_kvp_msg;
826 
827 			hv_kvp_convert_usermsg_to_hostmsg(umsg, hmsg);
828 			hv_kvp_respond_host(sc, KVP_SUCCESS);
829 			wakeup(sc);
830 			sc->req_in_progress = false;
831 		}
832 
833 		sc->daemon_busy = false;
834 		mtx_unlock(&sc->pending_mutex);
835 	}
836 
837 	return (error);
838 }
839 
840 
841 /*
842  * hv_kvp_daemon poll invokes this function to check if data is available
843  * for daemon to read.
844  */
845 static int
846 hv_kvp_dev_daemon_poll(struct cdev *dev, int events, struct thread *td)
847 {
848 	int revents = 0;
849 	hv_kvp_sc *sc = (hv_kvp_sc*)dev->si_drv1;
850 
851 	mtx_lock(&sc->pending_mutex);
852 	/*
853 	 * We check global flag daemon_busy for the data availiability for
854 	 * userland to read. Deamon_busy is set to true before driver has data
855 	 * for daemon to read. It is set to false after daemon sends
856 	 * then response back to driver.
857 	 */
858 	if (sc->daemon_busy == true)
859 		revents = POLLIN;
860 	else
861 		selrecord(td, &sc->hv_kvp_selinfo);
862 
863 	mtx_unlock(&sc->pending_mutex);
864 
865 	return (revents);
866 }
867 
868 static int
869 hv_kvp_probe(device_t dev)
870 {
871 	if (resource_disabled("hvkvp", 0))
872 		return ENXIO;
873 
874 	if (VMBUS_PROBE_GUID(device_get_parent(dev), dev, &service_guid) == 0) {
875 		device_set_desc(dev, "Hyper-V KVP Service");
876 		return BUS_PROBE_DEFAULT;
877 	}
878 	return ENXIO;
879 }
880 
881 static int
882 hv_kvp_attach(device_t dev)
883 {
884 	int error;
885 	struct sysctl_oid_list *child;
886 	struct sysctl_ctx_list *ctx;
887 
888 	hv_kvp_sc *sc = (hv_kvp_sc*)device_get_softc(dev);
889 
890 	sc->util_sc.callback = hv_kvp_callback;
891 	sema_init(&sc->dev_sema, 0, "hv_kvp device semaphore");
892 	mtx_init(&sc->pending_mutex, "hv-kvp pending mutex",
893 		NULL, MTX_DEF);
894 
895 	ctx = device_get_sysctl_ctx(dev);
896 	child = SYSCTL_CHILDREN(device_get_sysctl_tree(dev));
897 
898 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "hv_kvp_log",
899 	    CTLFLAG_RW, &hv_kvp_log, 0, "Hyperv KVP service log level");
900 
901 	TASK_INIT(&sc->task, 0, hv_kvp_process_request, sc);
902 
903 	/* create character device */
904 	error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
905 			&sc->hv_kvp_dev,
906 			&hv_kvp_cdevsw,
907 			0,
908 			UID_ROOT,
909 			GID_WHEEL,
910 			0640,
911 			"hv_kvp_dev");
912 
913 	if (error != 0)
914 		return (error);
915 	sc->hv_kvp_dev->si_drv1 = sc;
916 
917 	return hv_util_attach(dev);
918 }
919 
920 static int
921 hv_kvp_detach(device_t dev)
922 {
923 	hv_kvp_sc *sc = (hv_kvp_sc*)device_get_softc(dev);
924 
925 	if (sc->daemon_task != NULL) {
926 		PROC_LOCK(sc->daemon_task);
927 		kern_psignal(sc->daemon_task, SIGKILL);
928 		PROC_UNLOCK(sc->daemon_task);
929 	}
930 
931 	destroy_dev(sc->hv_kvp_dev);
932 	return hv_util_detach(dev);
933 }
934 
935 static device_method_t kvp_methods[] = {
936 	/* Device interface */
937 	DEVMETHOD(device_probe, hv_kvp_probe),
938 	DEVMETHOD(device_attach, hv_kvp_attach),
939 	DEVMETHOD(device_detach, hv_kvp_detach),
940 	{ 0, 0 }
941 };
942 
943 static driver_t kvp_driver = { "hvkvp", kvp_methods, sizeof(hv_kvp_sc)};
944 
945 static devclass_t kvp_devclass;
946 
947 DRIVER_MODULE(hv_kvp, vmbus, kvp_driver, kvp_devclass, NULL, NULL);
948 MODULE_VERSION(hv_kvp, 1);
949 MODULE_DEPEND(hv_kvp, vmbus, 1, 1, 1);
950