xref: /freebsd/sys/dev/hyperv/utilities/hv_kvp.c (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
1 /*-
2  * Copyright (c) 2014 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 #include <net/if_arp.h>
62 
63 #include <dev/hyperv/include/hyperv.h>
64 #include <dev/hyperv/netvsc/hv_net_vsc.h>
65 
66 #include "unicode.h"
67 #include "hv_kvp.h"
68 
69 /* hv_kvp defines */
70 #define BUFFERSIZE	sizeof(struct hv_kvp_msg)
71 #define KVP_SUCCESS	0
72 #define KVP_ERROR	1
73 #define kvp_hdr		hdr.kvp_hdr
74 
75 /* hv_kvp debug control */
76 static int hv_kvp_log = 0;
77 SYSCTL_INT(_dev, OID_AUTO, hv_kvp_log, CTLFLAG_RW, &hv_kvp_log, 0,
78 	"hv_kvp log");
79 
80 #define	hv_kvp_log_error(...)	do {				\
81 	if (hv_kvp_log > 0)				\
82 		log(LOG_ERR, "hv_kvp: " __VA_ARGS__);	\
83 } while (0)
84 
85 #define	hv_kvp_log_info(...) do {				\
86 	if (hv_kvp_log > 1)				\
87 		log(LOG_INFO, "hv_kvp: " __VA_ARGS__);		\
88 } while (0)
89 
90 /* character device prototypes */
91 static d_open_t		hv_kvp_dev_open;
92 static d_close_t	hv_kvp_dev_close;
93 static d_read_t		hv_kvp_dev_daemon_read;
94 static d_write_t	hv_kvp_dev_daemon_write;
95 static d_poll_t		hv_kvp_dev_daemon_poll;
96 
97 /* hv_kvp prototypes */
98 static int	hv_kvp_req_in_progress(void);
99 static void	hv_kvp_transaction_init(uint32_t, hv_vmbus_channel *, uint64_t, uint8_t *);
100 static void	hv_kvp_send_msg_to_daemon(void);
101 static void	hv_kvp_process_request(void *context);
102 
103 /* hv_kvp character device structure */
104 static struct cdevsw hv_kvp_cdevsw =
105 {
106 	.d_version	= D_VERSION,
107 	.d_open		= hv_kvp_dev_open,
108 	.d_close	= hv_kvp_dev_close,
109 	.d_read		= hv_kvp_dev_daemon_read,
110 	.d_write	= hv_kvp_dev_daemon_write,
111 	.d_poll		= hv_kvp_dev_daemon_poll,
112 	.d_name		= "hv_kvp_dev",
113 };
114 static struct cdev *hv_kvp_dev;
115 static struct hv_kvp_msg *hv_kvp_dev_buf;
116 struct proc *daemon_task;
117 
118 static struct selinfo hv_kvp_selinfo;
119 
120 /*
121  * Global state to track and synchronize multiple
122  * KVP transaction requests from the host.
123  */
124 static struct {
125 
126 	/* Pre-allocated work item for queue */
127 	hv_work_item		work_item;
128 
129 	/* Unless specified the pending mutex should be
130 	 * used to alter the values of the following paramters:
131 	 * 1. req_in_progress
132 	 * 2. req_timed_out
133 	 * 3. pending_reqs.
134 	 */
135 	struct mtx		pending_mutex;
136 
137 	/* To track if transaction is active or not */
138 	boolean_t		req_in_progress;
139 	/* Tracks if daemon did not reply back in time */
140 	boolean_t		req_timed_out;
141 	/* Tracks if daemon is serving a request currently */
142 	boolean_t		daemon_busy;
143 	/* Count of KVP requests from Hyper-V. */
144 	uint64_t		pending_reqs;
145 
146 
147 	/* Length of host message */
148 	uint32_t		host_msg_len;
149 
150 	/* Pointer to channel */
151 	hv_vmbus_channel	*channelp;
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 } kvp_globals;
174 
175 /* global vars */
176 MALLOC_DECLARE(M_HV_KVP_DEV_BUF);
177 MALLOC_DEFINE(M_HV_KVP_DEV_BUF, "hv_kvp_dev buffer", "buffer for hv_kvp_dev module");
178 
179 /*
180  * hv_kvp low level functions
181  */
182 
183 /*
184  * Check if kvp transaction is in progres
185  */
186 static int
187 hv_kvp_req_in_progress(void)
188 {
189 
190 	return (kvp_globals.req_in_progress);
191 }
192 
193 
194 /*
195  * This routine is called whenever a message is received from the host
196  */
197 static void
198 hv_kvp_transaction_init(uint32_t rcv_len, hv_vmbus_channel *rcv_channel,
199 			uint64_t request_id, uint8_t *rcv_buf)
200 {
201 
202 	/* Store all the relevant message details in the global structure */
203 	/* Do not need to use mutex for req_in_progress here */
204 	kvp_globals.req_in_progress = true;
205 	kvp_globals.host_msg_len = rcv_len;
206 	kvp_globals.channelp = rcv_channel;
207 	kvp_globals.host_msg_id = request_id;
208 	kvp_globals.rcv_buf = rcv_buf;
209 	kvp_globals.host_kvp_msg = (struct hv_kvp_msg *)&rcv_buf[
210 		sizeof(struct hv_vmbus_pipe_hdr) +
211 		sizeof(struct hv_vmbus_icmsg_hdr)];
212 }
213 
214 
215 /*
216  * hv_kvp - version neogtiation function
217  */
218 static void
219 hv_kvp_negotiate_version(struct hv_vmbus_icmsg_hdr *icmsghdrp,
220 			 struct hv_vmbus_icmsg_negotiate *negop,
221 			 uint8_t *buf)
222 {
223 	int icframe_vercnt;
224 	int icmsg_vercnt;
225 
226 	icmsghdrp->icmsgsize = 0x10;
227 
228 	negop = (struct hv_vmbus_icmsg_negotiate *)&buf[
229 		sizeof(struct hv_vmbus_pipe_hdr) +
230 		sizeof(struct hv_vmbus_icmsg_hdr)];
231 	icframe_vercnt = negop->icframe_vercnt;
232 	icmsg_vercnt = negop->icmsg_vercnt;
233 
234 	/*
235 	 * Select the framework version number we will support
236 	 */
237 	if ((icframe_vercnt >= 2) && (negop->icversion_data[1].major == 3)) {
238 		icframe_vercnt = 3;
239 		if (icmsg_vercnt > 2)
240 			icmsg_vercnt = 4;
241 		else
242 			icmsg_vercnt = 3;
243 	} else {
244 		icframe_vercnt = 1;
245 		icmsg_vercnt = 1;
246 	}
247 
248 	negop->icframe_vercnt = 1;
249 	negop->icmsg_vercnt = 1;
250 	negop->icversion_data[0].major = icframe_vercnt;
251 	negop->icversion_data[0].minor = 0;
252 	negop->icversion_data[1].major = icmsg_vercnt;
253 	negop->icversion_data[1].minor = 0;
254 }
255 
256 
257 /*
258  * Convert ip related info in umsg from utf8 to utf16 and store in hmsg
259  */
260 static int
261 hv_kvp_convert_utf8_ipinfo_to_utf16(struct hv_kvp_msg *umsg,
262 				    struct hv_kvp_ip_msg *host_ip_msg)
263 {
264 	int err_ip, err_subnet, err_gway, err_dns, err_adap;
265 	int UNUSED_FLAG = 1;
266 
267 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.ip_addr,
268 	    MAX_IP_ADDR_SIZE,
269 	    (char *)umsg->body.kvp_ip_val.ip_addr,
270 	    strlen((char *)umsg->body.kvp_ip_val.ip_addr),
271 	    UNUSED_FLAG,
272 	    &err_ip);
273 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.sub_net,
274 	    MAX_IP_ADDR_SIZE,
275 	    (char *)umsg->body.kvp_ip_val.sub_net,
276 	    strlen((char *)umsg->body.kvp_ip_val.sub_net),
277 	    UNUSED_FLAG,
278 	    &err_subnet);
279 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.gate_way,
280 	    MAX_GATEWAY_SIZE,
281 	    (char *)umsg->body.kvp_ip_val.gate_way,
282 	    strlen((char *)umsg->body.kvp_ip_val.gate_way),
283 	    UNUSED_FLAG,
284 	    &err_gway);
285 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.dns_addr,
286 	    MAX_IP_ADDR_SIZE,
287 	    (char *)umsg->body.kvp_ip_val.dns_addr,
288 	    strlen((char *)umsg->body.kvp_ip_val.dns_addr),
289 	    UNUSED_FLAG,
290 	    &err_dns);
291 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.adapter_id,
292 	    MAX_IP_ADDR_SIZE,
293 	    (char *)umsg->body.kvp_ip_val.adapter_id,
294 	    strlen((char *)umsg->body.kvp_ip_val.adapter_id),
295 	    UNUSED_FLAG,
296 	    &err_adap);
297 
298 	host_ip_msg->kvp_ip_val.dhcp_enabled = umsg->body.kvp_ip_val.dhcp_enabled;
299 	host_ip_msg->kvp_ip_val.addr_family = umsg->body.kvp_ip_val.addr_family;
300 
301 	return (err_ip | err_subnet | err_gway | err_dns | err_adap);
302 }
303 
304 
305 /*
306  * Convert ip related info in hmsg from utf16 to utf8 and store in umsg
307  */
308 static int
309 hv_kvp_convert_utf16_ipinfo_to_utf8(struct hv_kvp_ip_msg *host_ip_msg,
310 				    struct hv_kvp_msg *umsg)
311 {
312 	int err_ip, err_subnet, err_gway, err_dns, err_adap;
313 	int UNUSED_FLAG = 1;
314 	int guid_index;
315 	struct hv_device *hv_dev;       /* GUID Data Structure */
316 	hn_softc_t *sc;                 /* hn softc structure  */
317 	char if_name[4];
318 	unsigned char guid_instance[40];
319 	char *guid_data = NULL;
320 	char buf[39];
321 
322 	struct guid_extract {
323 		char	a1[2];
324 		char	a2[2];
325 		char	a3[2];
326 		char	a4[2];
327 		char	b1[2];
328 		char	b2[2];
329 		char	c1[2];
330 		char	c2[2];
331 		char	d[4];
332 		char	e[12];
333 	};
334 
335 	struct guid_extract *id;
336 	device_t *devs;
337 	int devcnt;
338 
339 	/* IP Address */
340 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.ip_addr,
341 	    MAX_IP_ADDR_SIZE,
342 	    (uint16_t *)host_ip_msg->kvp_ip_val.ip_addr,
343 	    MAX_IP_ADDR_SIZE,
344 	    UNUSED_FLAG,
345 	    &err_ip);
346 
347 	/* Adapter ID : GUID */
348 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.adapter_id,
349 	    MAX_ADAPTER_ID_SIZE,
350 	    (uint16_t *)host_ip_msg->kvp_ip_val.adapter_id,
351 	    MAX_ADAPTER_ID_SIZE,
352 	    UNUSED_FLAG,
353 	    &err_adap);
354 
355 	if (devclass_get_devices(devclass_find("hn"), &devs, &devcnt) == 0) {
356 		for (devcnt = devcnt - 1; devcnt >= 0; devcnt--) {
357 			sc = device_get_softc(devs[devcnt]);
358 
359 			/* Trying to find GUID of Network Device */
360 			hv_dev = sc->hn_dev_obj;
361 
362 			for (guid_index = 0; guid_index < 16; guid_index++) {
363 				sprintf(&guid_instance[guid_index * 2], "%02x",
364 				    hv_dev->device_id.data[guid_index]);
365 			}
366 
367 			guid_data = (char *)guid_instance;
368 			id = (struct guid_extract *)guid_data;
369 			snprintf(buf, sizeof(buf), "{%.2s%.2s%.2s%.2s-%.2s%.2s-%.2s%.2s-%.4s-%s}",
370 			    id->a4, id->a3, id->a2, id->a1,
371 			    id->b2, id->b1, id->c2, id->c1, id->d, id->e);
372 			guid_data = NULL;
373 			sprintf(if_name, "%s%d", "hn", device_get_unit(devs[devcnt]));
374 
375 			if (strncmp(buf, (char *)umsg->body.kvp_ip_val.adapter_id, 39) == 0) {
376 				strcpy((char *)umsg->body.kvp_ip_val.adapter_id, if_name);
377 				break;
378 			}
379 		}
380 		free(devs, M_TEMP);
381 	}
382 
383 	/* Address Family , DHCP , SUBNET, Gateway, DNS */
384 	umsg->kvp_hdr.operation = host_ip_msg->operation;
385 	umsg->body.kvp_ip_val.addr_family = host_ip_msg->kvp_ip_val.addr_family;
386 	umsg->body.kvp_ip_val.dhcp_enabled = host_ip_msg->kvp_ip_val.dhcp_enabled;
387 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.sub_net, MAX_IP_ADDR_SIZE,
388 	    (uint16_t *)host_ip_msg->kvp_ip_val.sub_net,
389 	    MAX_IP_ADDR_SIZE,
390 	    UNUSED_FLAG,
391 	    &err_subnet);
392 
393 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.gate_way, MAX_GATEWAY_SIZE,
394 	    (uint16_t *)host_ip_msg->kvp_ip_val.gate_way,
395 	    MAX_GATEWAY_SIZE,
396 	    UNUSED_FLAG,
397 	    &err_gway);
398 
399 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.dns_addr, MAX_IP_ADDR_SIZE,
400 	    (uint16_t *)host_ip_msg->kvp_ip_val.dns_addr,
401 	    MAX_IP_ADDR_SIZE,
402 	    UNUSED_FLAG,
403 	    &err_dns);
404 
405 	return (err_ip | err_subnet | err_gway | err_dns | err_adap);
406 }
407 
408 
409 /*
410  * Prepare a user kvp msg based on host kvp msg (utf16 to utf8)
411  * Ensure utf16_utf8 takes care of the additional string terminating char!!
412  */
413 static void
414 hv_kvp_convert_hostmsg_to_usermsg(void)
415 {
416 	int utf_err = 0;
417 	uint32_t value_type;
418 	struct hv_kvp_ip_msg *host_ip_msg = (struct hv_kvp_ip_msg *)
419 		kvp_globals.host_kvp_msg;
420 
421 	struct hv_kvp_msg *hmsg = kvp_globals.host_kvp_msg;
422 	struct hv_kvp_msg *umsg = &kvp_globals.daemon_kvp_msg;
423 
424 	memset(umsg, 0, sizeof(struct hv_kvp_msg));
425 
426 	umsg->kvp_hdr.operation = hmsg->kvp_hdr.operation;
427 	umsg->kvp_hdr.pool = hmsg->kvp_hdr.pool;
428 
429 	switch (umsg->kvp_hdr.operation) {
430 	case HV_KVP_OP_SET_IP_INFO:
431 		hv_kvp_convert_utf16_ipinfo_to_utf8(host_ip_msg, umsg);
432 		break;
433 
434 	case HV_KVP_OP_GET_IP_INFO:
435 		utf16_to_utf8((char *)umsg->body.kvp_ip_val.adapter_id,
436 		    MAX_ADAPTER_ID_SIZE,
437 		    (uint16_t *)host_ip_msg->kvp_ip_val.adapter_id,
438 		    MAX_ADAPTER_ID_SIZE, 1, &utf_err);
439 
440 		umsg->body.kvp_ip_val.addr_family =
441 		    host_ip_msg->kvp_ip_val.addr_family;
442 		break;
443 
444 	case HV_KVP_OP_SET:
445 		value_type = hmsg->body.kvp_set.data.value_type;
446 
447 		switch (value_type) {
448 		case HV_REG_SZ:
449 			umsg->body.kvp_set.data.value_size =
450 			    utf16_to_utf8(
451 				(char *)umsg->body.kvp_set.data.msg_value.value,
452 				HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1,
453 				(uint16_t *)hmsg->body.kvp_set.data.msg_value.value,
454 				hmsg->body.kvp_set.data.value_size,
455 				1, &utf_err);
456 			/* utf8 encoding */
457 			umsg->body.kvp_set.data.value_size =
458 			    umsg->body.kvp_set.data.value_size / 2;
459 			break;
460 
461 		case HV_REG_U32:
462 			umsg->body.kvp_set.data.value_size =
463 			    sprintf(umsg->body.kvp_set.data.msg_value.value, "%d",
464 				hmsg->body.kvp_set.data.msg_value.value_u32) + 1;
465 			break;
466 
467 		case HV_REG_U64:
468 			umsg->body.kvp_set.data.value_size =
469 			    sprintf(umsg->body.kvp_set.data.msg_value.value, "%llu",
470 				(unsigned long long)
471 				hmsg->body.kvp_set.data.msg_value.value_u64) + 1;
472 			break;
473 		}
474 
475 		umsg->body.kvp_set.data.key_size =
476 		    utf16_to_utf8(
477 			umsg->body.kvp_set.data.key,
478 			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1,
479 			(uint16_t *)hmsg->body.kvp_set.data.key,
480 			hmsg->body.kvp_set.data.key_size,
481 			1, &utf_err);
482 
483 		/* utf8 encoding */
484 		umsg->body.kvp_set.data.key_size =
485 		    umsg->body.kvp_set.data.key_size / 2;
486 		break;
487 
488 	case HV_KVP_OP_GET:
489 		umsg->body.kvp_get.data.key_size =
490 		    utf16_to_utf8(umsg->body.kvp_get.data.key,
491 			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1,
492 			(uint16_t *)hmsg->body.kvp_get.data.key,
493 			hmsg->body.kvp_get.data.key_size,
494 			1, &utf_err);
495 		/* utf8 encoding */
496 		umsg->body.kvp_get.data.key_size =
497 		    umsg->body.kvp_get.data.key_size / 2;
498 		break;
499 
500 	case HV_KVP_OP_DELETE:
501 		umsg->body.kvp_delete.key_size =
502 		    utf16_to_utf8(umsg->body.kvp_delete.key,
503 			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1,
504 			(uint16_t *)hmsg->body.kvp_delete.key,
505 			hmsg->body.kvp_delete.key_size,
506 			1, &utf_err);
507 		/* utf8 encoding */
508 		umsg->body.kvp_delete.key_size =
509 		    umsg->body.kvp_delete.key_size / 2;
510 		break;
511 
512 	case HV_KVP_OP_ENUMERATE:
513 		umsg->body.kvp_enum_data.index =
514 		    hmsg->body.kvp_enum_data.index;
515 		break;
516 
517 	default:
518 		hv_kvp_log_info("%s: daemon_kvp_msg: Invalid operation : %d\n",
519 		    __func__, umsg->kvp_hdr.operation);
520 	}
521 }
522 
523 
524 /*
525  * Prepare a host kvp msg based on user kvp msg (utf8 to utf16)
526  */
527 static int
528 hv_kvp_convert_usermsg_to_hostmsg(void)
529 {
530 	int hkey_len = 0, hvalue_len = 0, utf_err = 0;
531 	struct hv_kvp_exchg_msg_value *host_exchg_data;
532 	char *key_name, *value;
533 
534 	struct hv_kvp_msg *umsg = &kvp_globals.daemon_kvp_msg;
535 	struct hv_kvp_msg *hmsg = kvp_globals.host_kvp_msg;
536 	struct hv_kvp_ip_msg *host_ip_msg = (struct hv_kvp_ip_msg *)hmsg;
537 
538 	switch (hmsg->kvp_hdr.operation) {
539 	case HV_KVP_OP_GET_IP_INFO:
540 		return (hv_kvp_convert_utf8_ipinfo_to_utf16(umsg, host_ip_msg));
541 
542 	case HV_KVP_OP_SET_IP_INFO:
543 	case HV_KVP_OP_SET:
544 	case HV_KVP_OP_DELETE:
545 		return (KVP_SUCCESS);
546 
547 	case HV_KVP_OP_ENUMERATE:
548 		host_exchg_data = &hmsg->body.kvp_enum_data.data;
549 		key_name = umsg->body.kvp_enum_data.data.key;
550 		hkey_len = utf8_to_utf16((uint16_t *)host_exchg_data->key,
551 				((HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2),
552 				key_name, strlen(key_name),
553 				1, &utf_err);
554 		/* utf16 encoding */
555 		host_exchg_data->key_size = 2 * (hkey_len + 1);
556 		value = umsg->body.kvp_enum_data.data.msg_value.value;
557 		hvalue_len = utf8_to_utf16(
558 				(uint16_t *)host_exchg_data->msg_value.value,
559 				((HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2),
560 				value, strlen(value),
561 				1, &utf_err);
562 		host_exchg_data->value_size = 2 * (hvalue_len + 1);
563 		host_exchg_data->value_type = HV_REG_SZ;
564 
565 		if ((hkey_len < 0) || (hvalue_len < 0))
566 			return (HV_KVP_E_FAIL);
567 
568 		return (KVP_SUCCESS);
569 
570 	case HV_KVP_OP_GET:
571 		host_exchg_data = &hmsg->body.kvp_get.data;
572 		value = umsg->body.kvp_get.data.msg_value.value;
573 		hvalue_len = utf8_to_utf16(
574 				(uint16_t *)host_exchg_data->msg_value.value,
575 				((HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2),
576 				value, strlen(value),
577 				1, &utf_err);
578 		/* Convert value size to uft16 */
579 		host_exchg_data->value_size = 2 * (hvalue_len + 1);
580 		/* Use values by string */
581 		host_exchg_data->value_type = HV_REG_SZ;
582 
583 		if ((hkey_len < 0) || (hvalue_len < 0))
584 			return (HV_KVP_E_FAIL);
585 
586 		return (KVP_SUCCESS);
587 
588 	default:
589 		return (HV_KVP_E_FAIL);
590 	}
591 }
592 
593 
594 /*
595  * Send the response back to the host.
596  */
597 static void
598 hv_kvp_respond_host(int error)
599 {
600 	struct hv_vmbus_icmsg_hdr *hv_icmsg_hdrp;
601 
602 	hv_icmsg_hdrp = (struct hv_vmbus_icmsg_hdr *)
603 	    &kvp_globals.rcv_buf[sizeof(struct hv_vmbus_pipe_hdr)];
604 
605 	if (error)
606 		error = HV_KVP_E_FAIL;
607 
608 	hv_icmsg_hdrp->status = error;
609 	hv_icmsg_hdrp->icflags = HV_ICMSGHDRFLAG_TRANSACTION | HV_ICMSGHDRFLAG_RESPONSE;
610 
611 	error = hv_vmbus_channel_send_packet(kvp_globals.channelp,
612 			kvp_globals.rcv_buf,
613 			kvp_globals.host_msg_len, kvp_globals.host_msg_id,
614 			HV_VMBUS_PACKET_TYPE_DATA_IN_BAND, 0);
615 
616 	if (error)
617 		hv_kvp_log_info("%s: hv_kvp_respond_host: sendpacket error:%d\n",
618 			__func__, error);
619 }
620 
621 
622 /*
623  * This is the main kvp kernel process that interacts with both user daemon
624  * and the host
625  */
626 static void
627 hv_kvp_send_msg_to_daemon(void)
628 {
629 	/* Prepare kvp_msg to be sent to user */
630 	hv_kvp_convert_hostmsg_to_usermsg();
631 
632 	/* Send the msg to user via function deamon_read - setting sema */
633 	sema_post(&kvp_globals.dev_sema);
634 
635 	/* We should wake up the daemon, in case it's doing poll() */
636 	selwakeup(&hv_kvp_selinfo);
637 }
638 
639 
640 /*
641  * Function to read the kvp request buffer from host
642  * and interact with daemon
643  */
644 static void
645 hv_kvp_process_request(void *context)
646 {
647 	uint8_t *kvp_buf;
648 	hv_vmbus_channel *channel = context;
649 	uint32_t recvlen = 0;
650 	uint64_t requestid;
651 	struct hv_vmbus_icmsg_hdr *icmsghdrp;
652 	int ret = 0;
653 	uint64_t pending_cnt = 1;
654 
655 	hv_kvp_log_info("%s: entering hv_kvp_process_request\n", __func__);
656 	kvp_buf = receive_buffer[HV_KVP];
657 	ret = hv_vmbus_channel_recv_packet(channel, kvp_buf, 2 * PAGE_SIZE,
658 		&recvlen, &requestid);
659 
660 	/*
661 	 * We start counting only after the daemon registers
662 	 * and therefore there could be requests pending in
663 	 * the VMBus that are not reflected in pending_cnt.
664 	 * Therefore we continue reading as long as either of
665 	 * the below conditions is true.
666 	 */
667 
668 	while ((pending_cnt>0) || ((ret == 0) && (recvlen > 0))) {
669 
670 		if ((ret == 0) && (recvlen>0)) {
671 
672 			icmsghdrp = (struct hv_vmbus_icmsg_hdr *)
673 					&kvp_buf[sizeof(struct hv_vmbus_pipe_hdr)];
674 
675 			hv_kvp_transaction_init(recvlen, channel, requestid, kvp_buf);
676 			if (icmsghdrp->icmsgtype == HV_ICMSGTYPE_NEGOTIATE) {
677 				hv_kvp_negotiate_version(icmsghdrp, NULL, kvp_buf);
678 				hv_kvp_respond_host(ret);
679 
680 				/*
681 				 * It is ok to not acquire the mutex before setting
682 				 * req_in_progress here because negotiation is the
683 				 * first thing that happens and hence there is no
684 				 * chance of a race condition.
685 				 */
686 
687 				kvp_globals.req_in_progress = false;
688 				hv_kvp_log_info("%s :version negotiated\n", __func__);
689 
690 			} else {
691 				if (!kvp_globals.daemon_busy) {
692 
693 					hv_kvp_log_info("%s: issuing qury to daemon\n", __func__);
694 					mtx_lock(&kvp_globals.pending_mutex);
695 					kvp_globals.req_timed_out = false;
696 					kvp_globals.daemon_busy = true;
697 					mtx_unlock(&kvp_globals.pending_mutex);
698 
699 					hv_kvp_send_msg_to_daemon();
700 					hv_kvp_log_info("%s: waiting for daemon\n", __func__);
701 				}
702 
703 				/* Wait 5 seconds for daemon to respond back */
704 				tsleep(&kvp_globals, 0, "kvpworkitem", 5 * hz);
705 				hv_kvp_log_info("%s: came out of wait\n", __func__);
706 			}
707 		}
708 
709 		mtx_lock(&kvp_globals.pending_mutex);
710 
711 		/* Notice that once req_timed_out is set to true
712 		 * it will remain true until the next request is
713 		 * sent to the daemon. The response from daemon
714 		 * is forwarded to host only when this flag is
715 		 * false.
716 		 */
717 		kvp_globals.req_timed_out = true;
718 
719 		/*
720 		 * Cancel request if so need be.
721 		 */
722 		if (hv_kvp_req_in_progress()) {
723 			hv_kvp_log_info("%s: request was still active after wait so failing\n", __func__);
724 			hv_kvp_respond_host(HV_KVP_E_FAIL);
725 			kvp_globals.req_in_progress = false;
726 		}
727 
728 		/*
729 		* Decrement pending request count and
730 		*/
731 		if (kvp_globals.pending_reqs>0) {
732 			kvp_globals.pending_reqs = kvp_globals.pending_reqs - 1;
733 		}
734 		pending_cnt = kvp_globals.pending_reqs;
735 
736 		mtx_unlock(&kvp_globals.pending_mutex);
737 
738 		/*
739 		 * Try reading next buffer
740 		 */
741 		recvlen = 0;
742 		ret = hv_vmbus_channel_recv_packet(channel, kvp_buf, 2 * PAGE_SIZE,
743 			&recvlen, &requestid);
744 		hv_kvp_log_info("%s: read: context %p, pending_cnt %llu ret =%d, recvlen=%d\n",
745 			__func__, context, (unsigned long long)pending_cnt, ret, recvlen);
746 	}
747 }
748 
749 
750 /*
751  * Callback routine that gets called whenever there is a message from host
752  */
753 void
754 hv_kvp_callback(void *context)
755 {
756 	uint64_t pending_cnt = 0;
757 
758 	if (kvp_globals.register_done == false) {
759 
760 		kvp_globals.channelp = context;
761 	} else {
762 
763 		mtx_lock(&kvp_globals.pending_mutex);
764 		kvp_globals.pending_reqs = kvp_globals.pending_reqs + 1;
765 		pending_cnt = kvp_globals.pending_reqs;
766 		mtx_unlock(&kvp_globals.pending_mutex);
767 		if (pending_cnt == 1) {
768 			hv_kvp_log_info("%s: Queuing work item\n", __func__);
769 			hv_queue_work_item(
770 					service_table[HV_KVP].work_queue,
771 					hv_kvp_process_request,
772 					context
773 					);
774 		}
775 	}
776 }
777 
778 
779 /*
780  * This function is called by the hv_kvp_init -
781  * creates character device hv_kvp_dev
782  * allocates memory to hv_kvp_dev_buf
783  *
784  */
785 static int
786 hv_kvp_dev_init(void)
787 {
788 	int error = 0;
789 
790 	/* initialize semaphore */
791 	sema_init(&kvp_globals.dev_sema, 0, "hv_kvp device semaphore");
792 	/* create character device */
793 	error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
794 			&hv_kvp_dev,
795 			&hv_kvp_cdevsw,
796 			0,
797 			UID_ROOT,
798 			GID_WHEEL,
799 			0640,
800 			"hv_kvp_dev");
801 
802 	if (error != 0)
803 		return (error);
804 
805 	/*
806 	 * Malloc with M_WAITOK flag will never fail.
807 	 */
808 	hv_kvp_dev_buf = malloc(sizeof(*hv_kvp_dev_buf), M_HV_KVP_DEV_BUF, M_WAITOK |
809 				M_ZERO);
810 
811 	return (0);
812 }
813 
814 
815 /*
816  * This function is called by the hv_kvp_deinit -
817  * destroy character device
818  */
819 static void
820 hv_kvp_dev_destroy(void)
821 {
822 
823 	if (daemon_task != NULL) {
824 		PROC_LOCK(daemon_task);
825 		kern_psignal(daemon_task, SIGKILL);
826 		PROC_UNLOCK(daemon_task);
827 	}
828 
829 	destroy_dev(hv_kvp_dev);
830 	free(hv_kvp_dev_buf, M_HV_KVP_DEV_BUF);
831 	return;
832 }
833 
834 
835 static int
836 hv_kvp_dev_open(struct cdev *dev, int oflags, int devtype,
837 				struct thread *td)
838 {
839 
840 	hv_kvp_log_info("%s: Opened device \"hv_kvp_device\" successfully.\n", __func__);
841 	if (kvp_globals.dev_accessed)
842 		return (-EBUSY);
843 
844 	daemon_task = curproc;
845 	kvp_globals.dev_accessed = true;
846 	kvp_globals.daemon_busy = false;
847 	return (0);
848 }
849 
850 
851 static int
852 hv_kvp_dev_close(struct cdev *dev __unused, int fflag __unused, int devtype __unused,
853 				 struct thread *td __unused)
854 {
855 
856 	hv_kvp_log_info("%s: Closing device \"hv_kvp_device\".\n", __func__);
857 	kvp_globals.dev_accessed = false;
858 	kvp_globals.register_done = false;
859 	return (0);
860 }
861 
862 
863 /*
864  * hv_kvp_daemon read invokes this function
865  * acts as a send to daemon
866  */
867 static int
868 hv_kvp_dev_daemon_read(struct cdev *dev __unused, struct uio *uio, int ioflag __unused)
869 {
870 	size_t amt;
871 	int error = 0;
872 
873 	/* Check hv_kvp daemon registration status*/
874 	if (!kvp_globals.register_done)
875 		return (KVP_ERROR);
876 
877 	sema_wait(&kvp_globals.dev_sema);
878 
879 	memcpy(hv_kvp_dev_buf, &kvp_globals.daemon_kvp_msg, sizeof(struct hv_kvp_msg));
880 
881 	amt = MIN(uio->uio_resid, uio->uio_offset >= BUFFERSIZE + 1 ? 0 :
882 		BUFFERSIZE + 1 - uio->uio_offset);
883 
884 	if ((error = uiomove(hv_kvp_dev_buf, amt, uio)) != 0)
885 		hv_kvp_log_info("%s: hv_kvp uiomove read failed!\n", __func__);
886 
887 	return (error);
888 }
889 
890 
891 /*
892  * hv_kvp_daemon write invokes this function
893  * acts as a recieve from daemon
894  */
895 static int
896 hv_kvp_dev_daemon_write(struct cdev *dev __unused, struct uio *uio, int ioflag __unused)
897 {
898 	size_t amt;
899 	int error = 0;
900 
901 	uio->uio_offset = 0;
902 
903 	amt = MIN(uio->uio_resid, BUFFERSIZE);
904 	error = uiomove(hv_kvp_dev_buf, amt, uio);
905 
906 	if (error != 0)
907 		return (error);
908 
909 	memcpy(&kvp_globals.daemon_kvp_msg, hv_kvp_dev_buf, sizeof(struct hv_kvp_msg));
910 
911 	if (kvp_globals.register_done == false) {
912 		if (kvp_globals.daemon_kvp_msg.kvp_hdr.operation == HV_KVP_OP_REGISTER) {
913 
914 			kvp_globals.register_done = true;
915 			if (kvp_globals.channelp) {
916 
917 				hv_kvp_callback(kvp_globals.channelp);
918 			}
919 		}
920 		else {
921 			hv_kvp_log_info("%s, KVP Registration Failed\n", __func__);
922 			return (KVP_ERROR);
923 		}
924 	} else {
925 
926 		mtx_lock(&kvp_globals.pending_mutex);
927 
928 		if(!kvp_globals.req_timed_out) {
929 
930 			hv_kvp_convert_usermsg_to_hostmsg();
931 			hv_kvp_respond_host(KVP_SUCCESS);
932 			wakeup(&kvp_globals);
933 			kvp_globals.req_in_progress = false;
934 		}
935 
936 		kvp_globals.daemon_busy = false;
937 		mtx_unlock(&kvp_globals.pending_mutex);
938 	}
939 
940 	return (error);
941 }
942 
943 
944 /*
945  * hv_kvp_daemon poll invokes this function to check if data is available
946  * for daemon to read.
947  */
948 static int
949 hv_kvp_dev_daemon_poll(struct cdev *dev __unused, int events, struct thread *td)
950 {
951 	int revents = 0;
952 
953 	mtx_lock(&kvp_globals.pending_mutex);
954 	/*
955 	 * We check global flag daemon_busy for the data availiability for
956 	 * userland to read. Deamon_busy is set to true before driver has data
957 	 * for daemon to read. It is set to false after daemon sends
958 	 * then response back to driver.
959 	 */
960 	if (kvp_globals.daemon_busy == true)
961 		revents = POLLIN;
962 	else
963 		selrecord(td, &hv_kvp_selinfo);
964 
965 	mtx_unlock(&kvp_globals.pending_mutex);
966 
967 	return (revents);
968 }
969 
970 
971 /*
972  * hv_kvp initialization function
973  * called from hv_util service.
974  *
975  */
976 int
977 hv_kvp_init(hv_vmbus_service *srv)
978 {
979 	int error = 0;
980 	hv_work_queue *work_queue = NULL;
981 
982 	memset(&kvp_globals, 0, sizeof(kvp_globals));
983 
984 	work_queue = hv_work_queue_create("KVP Service");
985 	if (work_queue == NULL) {
986 		hv_kvp_log_info("%s: Work queue alloc failed\n", __func__);
987 		error = ENOMEM;
988 		hv_kvp_log_error("%s: ENOMEM\n", __func__);
989 		goto Finish;
990 	}
991 	srv->work_queue = work_queue;
992 
993 	error = hv_kvp_dev_init();
994 	mtx_init(&kvp_globals.pending_mutex, "hv-kvp pending mutex",
995 		       	NULL, MTX_DEF);
996 	kvp_globals.pending_reqs = 0;
997 
998 
999 Finish:
1000 	return (error);
1001 }
1002 
1003 
1004 void
1005 hv_kvp_deinit(void)
1006 {
1007 	hv_kvp_dev_destroy();
1008 	mtx_destroy(&kvp_globals.pending_mutex);
1009 
1010 	return;
1011 }
1012