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1 /*
2  * An implementation of key value pair (KVP) functionality for Linux.
3  *
4  *
5  * Copyright (C) 2010, Novell, Inc.
6  * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License version 2 as published
10  * by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
15  * NON INFRINGEMENT.  See the GNU General Public License for more
16  * details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21  *
22  */
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24 
25 #include <linux/net.h>
26 #include <linux/nls.h>
27 #include <linux/connector.h>
28 #include <linux/workqueue.h>
29 #include <linux/hyperv.h>
30 
31 #include "hyperv_vmbus.h"
32 #include "hv_utils_transport.h"
33 
34 /*
35  * Pre win8 version numbers used in ws2008 and ws 2008 r2 (win7)
36  */
37 #define WS2008_SRV_MAJOR	1
38 #define WS2008_SRV_MINOR	0
39 #define WS2008_SRV_VERSION     (WS2008_SRV_MAJOR << 16 | WS2008_SRV_MINOR)
40 
41 #define WIN7_SRV_MAJOR   3
42 #define WIN7_SRV_MINOR   0
43 #define WIN7_SRV_VERSION     (WIN7_SRV_MAJOR << 16 | WIN7_SRV_MINOR)
44 
45 #define WIN8_SRV_MAJOR   4
46 #define WIN8_SRV_MINOR   0
47 #define WIN8_SRV_VERSION     (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
48 
49 /*
50  * Global state maintained for transaction that is being processed. For a class
51  * of integration services, including the "KVP service", the specified protocol
52  * is a "request/response" protocol which means that there can only be single
53  * outstanding transaction from the host at any given point in time. We use
54  * this to simplify memory management in this driver - we cache and process
55  * only one message at a time.
56  *
57  * While the request/response protocol is guaranteed by the host, we further
58  * ensure this by serializing packet processing in this driver - we do not
59  * read additional packets from the VMBUs until the current packet is fully
60  * handled.
61  */
62 
63 static struct {
64 	int state;   /* hvutil_device_state */
65 	int recv_len; /* number of bytes received. */
66 	struct hv_kvp_msg  *kvp_msg; /* current message */
67 	struct vmbus_channel *recv_channel; /* chn we got the request */
68 	u64 recv_req_id; /* request ID. */
69 } kvp_transaction;
70 
71 /*
72  * This state maintains the version number registered by the daemon.
73  */
74 static int dm_reg_value;
75 
76 static void kvp_send_key(struct work_struct *dummy);
77 
78 
79 static void kvp_respond_to_host(struct hv_kvp_msg *msg, int error);
80 static void kvp_timeout_func(struct work_struct *dummy);
81 static void kvp_host_handshake_func(struct work_struct *dummy);
82 static void kvp_register(int);
83 
84 static DECLARE_DELAYED_WORK(kvp_timeout_work, kvp_timeout_func);
85 static DECLARE_DELAYED_WORK(kvp_host_handshake_work, kvp_host_handshake_func);
86 static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);
87 
88 static const char kvp_devname[] = "vmbus/hv_kvp";
89 static u8 *recv_buffer;
90 static struct hvutil_transport *hvt;
91 static struct completion release_event;
92 /*
93  * Register the kernel component with the user-level daemon.
94  * As part of this registration, pass the LIC version number.
95  * This number has no meaning, it satisfies the registration protocol.
96  */
97 #define HV_DRV_VERSION           "3.1"
98 
kvp_poll_wrapper(void * channel)99 static void kvp_poll_wrapper(void *channel)
100 {
101 	/* Transaction is finished, reset the state here to avoid races. */
102 	kvp_transaction.state = HVUTIL_READY;
103 	hv_kvp_onchannelcallback(channel);
104 }
105 
106 static void
kvp_register(int reg_value)107 kvp_register(int reg_value)
108 {
109 
110 	struct hv_kvp_msg *kvp_msg;
111 	char *version;
112 
113 	kvp_msg = kzalloc(sizeof(*kvp_msg), GFP_KERNEL);
114 
115 	if (kvp_msg) {
116 		version = kvp_msg->body.kvp_register.version;
117 		kvp_msg->kvp_hdr.operation = reg_value;
118 		strcpy(version, HV_DRV_VERSION);
119 
120 		hvutil_transport_send(hvt, kvp_msg, sizeof(*kvp_msg));
121 		kfree(kvp_msg);
122 	}
123 }
124 
kvp_timeout_func(struct work_struct * dummy)125 static void kvp_timeout_func(struct work_struct *dummy)
126 {
127 	/*
128 	 * If the timer fires, the user-mode component has not responded;
129 	 * process the pending transaction.
130 	 */
131 	kvp_respond_to_host(NULL, HV_E_FAIL);
132 
133 	hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
134 }
135 
kvp_host_handshake_func(struct work_struct * dummy)136 static void kvp_host_handshake_func(struct work_struct *dummy)
137 {
138 	hv_poll_channel(kvp_transaction.recv_channel, hv_kvp_onchannelcallback);
139 }
140 
kvp_handle_handshake(struct hv_kvp_msg * msg)141 static int kvp_handle_handshake(struct hv_kvp_msg *msg)
142 {
143 	switch (msg->kvp_hdr.operation) {
144 	case KVP_OP_REGISTER:
145 		dm_reg_value = KVP_OP_REGISTER;
146 		pr_info("KVP: IP injection functionality not available\n");
147 		pr_info("KVP: Upgrade the KVP daemon\n");
148 		break;
149 	case KVP_OP_REGISTER1:
150 		dm_reg_value = KVP_OP_REGISTER1;
151 		break;
152 	default:
153 		pr_info("KVP: incompatible daemon\n");
154 		pr_info("KVP: KVP version: %d, Daemon version: %d\n",
155 			KVP_OP_REGISTER1, msg->kvp_hdr.operation);
156 		return -EINVAL;
157 	}
158 
159 	/*
160 	 * We have a compatible daemon; complete the handshake.
161 	 */
162 	pr_debug("KVP: userspace daemon ver. %d registered\n",
163 		 KVP_OP_REGISTER);
164 	kvp_register(dm_reg_value);
165 
166 	/*
167 	 * If we're still negotiating with the host cancel the timeout
168 	 * work to not poll the channel twice.
169 	 */
170 	cancel_delayed_work_sync(&kvp_host_handshake_work);
171 	hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
172 
173 	return 0;
174 }
175 
176 
177 /*
178  * Callback when data is received from user mode.
179  */
180 
kvp_on_msg(void * msg,int len)181 static int kvp_on_msg(void *msg, int len)
182 {
183 	struct hv_kvp_msg *message = (struct hv_kvp_msg *)msg;
184 	struct hv_kvp_msg_enumerate *data;
185 	int	error = 0;
186 
187 	if (len < sizeof(*message))
188 		return -EINVAL;
189 
190 	/*
191 	 * If we are negotiating the version information
192 	 * with the daemon; handle that first.
193 	 */
194 
195 	if (kvp_transaction.state < HVUTIL_READY) {
196 		return kvp_handle_handshake(message);
197 	}
198 
199 	/* We didn't send anything to userspace so the reply is spurious */
200 	if (kvp_transaction.state < HVUTIL_USERSPACE_REQ)
201 		return -EINVAL;
202 
203 	kvp_transaction.state = HVUTIL_USERSPACE_RECV;
204 
205 	/*
206 	 * Based on the version of the daemon, we propagate errors from the
207 	 * daemon differently.
208 	 */
209 
210 	data = &message->body.kvp_enum_data;
211 
212 	switch (dm_reg_value) {
213 	case KVP_OP_REGISTER:
214 		/*
215 		 * Null string is used to pass back error condition.
216 		 */
217 		if (data->data.key[0] == 0)
218 			error = HV_S_CONT;
219 		break;
220 
221 	case KVP_OP_REGISTER1:
222 		/*
223 		 * We use the message header information from
224 		 * the user level daemon to transmit errors.
225 		 */
226 		error = message->error;
227 		break;
228 	}
229 
230 	/*
231 	 * Complete the transaction by forwarding the key value
232 	 * to the host. But first, cancel the timeout.
233 	 */
234 	if (cancel_delayed_work_sync(&kvp_timeout_work)) {
235 		kvp_respond_to_host(message, error);
236 		hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
237 	}
238 
239 	return 0;
240 }
241 
242 
process_ob_ipinfo(void * in_msg,void * out_msg,int op)243 static int process_ob_ipinfo(void *in_msg, void *out_msg, int op)
244 {
245 	struct hv_kvp_msg *in = in_msg;
246 	struct hv_kvp_ip_msg *out = out_msg;
247 	int len;
248 
249 	switch (op) {
250 	case KVP_OP_GET_IP_INFO:
251 		/*
252 		 * Transform all parameters into utf16 encoding.
253 		 */
254 		len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.ip_addr,
255 				strlen((char *)in->body.kvp_ip_val.ip_addr),
256 				UTF16_HOST_ENDIAN,
257 				(wchar_t *)out->kvp_ip_val.ip_addr,
258 				MAX_IP_ADDR_SIZE);
259 		if (len < 0)
260 			return len;
261 
262 		len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.sub_net,
263 				strlen((char *)in->body.kvp_ip_val.sub_net),
264 				UTF16_HOST_ENDIAN,
265 				(wchar_t *)out->kvp_ip_val.sub_net,
266 				MAX_IP_ADDR_SIZE);
267 		if (len < 0)
268 			return len;
269 
270 		len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.gate_way,
271 				strlen((char *)in->body.kvp_ip_val.gate_way),
272 				UTF16_HOST_ENDIAN,
273 				(wchar_t *)out->kvp_ip_val.gate_way,
274 				MAX_GATEWAY_SIZE);
275 		if (len < 0)
276 			return len;
277 
278 		len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.dns_addr,
279 				strlen((char *)in->body.kvp_ip_val.dns_addr),
280 				UTF16_HOST_ENDIAN,
281 				(wchar_t *)out->kvp_ip_val.dns_addr,
282 				MAX_IP_ADDR_SIZE);
283 		if (len < 0)
284 			return len;
285 
286 		len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.adapter_id,
287 				strlen((char *)in->body.kvp_ip_val.adapter_id),
288 				UTF16_HOST_ENDIAN,
289 				(wchar_t *)out->kvp_ip_val.adapter_id,
290 				MAX_IP_ADDR_SIZE);
291 		if (len < 0)
292 			return len;
293 
294 		out->kvp_ip_val.dhcp_enabled =
295 			in->body.kvp_ip_val.dhcp_enabled;
296 		out->kvp_ip_val.addr_family =
297 			in->body.kvp_ip_val.addr_family;
298 	}
299 
300 	return 0;
301 }
302 
process_ib_ipinfo(void * in_msg,void * out_msg,int op)303 static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
304 {
305 	struct hv_kvp_ip_msg *in = in_msg;
306 	struct hv_kvp_msg *out = out_msg;
307 
308 	switch (op) {
309 	case KVP_OP_SET_IP_INFO:
310 		/*
311 		 * Transform all parameters into utf8 encoding.
312 		 */
313 		utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.ip_addr,
314 				MAX_IP_ADDR_SIZE,
315 				UTF16_LITTLE_ENDIAN,
316 				(__u8 *)out->body.kvp_ip_val.ip_addr,
317 				MAX_IP_ADDR_SIZE);
318 
319 		utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.sub_net,
320 				MAX_IP_ADDR_SIZE,
321 				UTF16_LITTLE_ENDIAN,
322 				(__u8 *)out->body.kvp_ip_val.sub_net,
323 				MAX_IP_ADDR_SIZE);
324 
325 		utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.gate_way,
326 				MAX_GATEWAY_SIZE,
327 				UTF16_LITTLE_ENDIAN,
328 				(__u8 *)out->body.kvp_ip_val.gate_way,
329 				MAX_GATEWAY_SIZE);
330 
331 		utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.dns_addr,
332 				MAX_IP_ADDR_SIZE,
333 				UTF16_LITTLE_ENDIAN,
334 				(__u8 *)out->body.kvp_ip_val.dns_addr,
335 				MAX_IP_ADDR_SIZE);
336 
337 		out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled;
338 
339 	default:
340 		utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
341 				MAX_ADAPTER_ID_SIZE,
342 				UTF16_LITTLE_ENDIAN,
343 				(__u8 *)out->body.kvp_ip_val.adapter_id,
344 				MAX_ADAPTER_ID_SIZE);
345 
346 		out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
347 	}
348 }
349 
350 
351 
352 
353 static void
kvp_send_key(struct work_struct * dummy)354 kvp_send_key(struct work_struct *dummy)
355 {
356 	struct hv_kvp_msg *message;
357 	struct hv_kvp_msg *in_msg;
358 	__u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
359 	__u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
360 	__u32 val32;
361 	__u64 val64;
362 	int rc;
363 
364 	/* The transaction state is wrong. */
365 	if (kvp_transaction.state != HVUTIL_HOSTMSG_RECEIVED)
366 		return;
367 
368 	message = kzalloc(sizeof(*message), GFP_KERNEL);
369 	if (!message)
370 		return;
371 
372 	message->kvp_hdr.operation = operation;
373 	message->kvp_hdr.pool = pool;
374 	in_msg = kvp_transaction.kvp_msg;
375 
376 	/*
377 	 * The key/value strings sent from the host are encoded in
378 	 * in utf16; convert it to utf8 strings.
379 	 * The host assures us that the utf16 strings will not exceed
380 	 * the max lengths specified. We will however, reserve room
381 	 * for the string terminating character - in the utf16s_utf8s()
382 	 * function we limit the size of the buffer where the converted
383 	 * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to gaurantee
384 	 * that the strings can be properly terminated!
385 	 */
386 
387 	switch (message->kvp_hdr.operation) {
388 	case KVP_OP_SET_IP_INFO:
389 		process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
390 		break;
391 	case KVP_OP_GET_IP_INFO:
392 		process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
393 		break;
394 	case KVP_OP_SET:
395 		switch (in_msg->body.kvp_set.data.value_type) {
396 		case REG_SZ:
397 			/*
398 			 * The value is a string - utf16 encoding.
399 			 */
400 			message->body.kvp_set.data.value_size =
401 				utf16s_to_utf8s(
402 				(wchar_t *)in_msg->body.kvp_set.data.value,
403 				in_msg->body.kvp_set.data.value_size,
404 				UTF16_LITTLE_ENDIAN,
405 				message->body.kvp_set.data.value,
406 				HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
407 				break;
408 
409 		case REG_U32:
410 			/*
411 			 * The value is a 32 bit scalar.
412 			 * We save this as a utf8 string.
413 			 */
414 			val32 = in_msg->body.kvp_set.data.value_u32;
415 			message->body.kvp_set.data.value_size =
416 				sprintf(message->body.kvp_set.data.value,
417 					"%d", val32) + 1;
418 			break;
419 
420 		case REG_U64:
421 			/*
422 			 * The value is a 64 bit scalar.
423 			 * We save this as a utf8 string.
424 			 */
425 			val64 = in_msg->body.kvp_set.data.value_u64;
426 			message->body.kvp_set.data.value_size =
427 				sprintf(message->body.kvp_set.data.value,
428 					"%llu", val64) + 1;
429 			break;
430 
431 		}
432 	case KVP_OP_GET:
433 		message->body.kvp_set.data.key_size =
434 			utf16s_to_utf8s(
435 			(wchar_t *)in_msg->body.kvp_set.data.key,
436 			in_msg->body.kvp_set.data.key_size,
437 			UTF16_LITTLE_ENDIAN,
438 			message->body.kvp_set.data.key,
439 			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
440 			break;
441 
442 	case KVP_OP_DELETE:
443 		message->body.kvp_delete.key_size =
444 			utf16s_to_utf8s(
445 			(wchar_t *)in_msg->body.kvp_delete.key,
446 			in_msg->body.kvp_delete.key_size,
447 			UTF16_LITTLE_ENDIAN,
448 			message->body.kvp_delete.key,
449 			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
450 			break;
451 
452 	case KVP_OP_ENUMERATE:
453 		message->body.kvp_enum_data.index =
454 			in_msg->body.kvp_enum_data.index;
455 			break;
456 	}
457 
458 	kvp_transaction.state = HVUTIL_USERSPACE_REQ;
459 	rc = hvutil_transport_send(hvt, message, sizeof(*message));
460 	if (rc) {
461 		pr_debug("KVP: failed to communicate to the daemon: %d\n", rc);
462 		if (cancel_delayed_work_sync(&kvp_timeout_work)) {
463 			kvp_respond_to_host(message, HV_E_FAIL);
464 			kvp_transaction.state = HVUTIL_READY;
465 		}
466 	}
467 
468 	kfree(message);
469 
470 	return;
471 }
472 
473 /*
474  * Send a response back to the host.
475  */
476 
477 static void
kvp_respond_to_host(struct hv_kvp_msg * msg_to_host,int error)478 kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
479 {
480 	struct hv_kvp_msg  *kvp_msg;
481 	struct hv_kvp_exchg_msg_value  *kvp_data;
482 	char	*key_name;
483 	char	*value;
484 	struct icmsg_hdr *icmsghdrp;
485 	int	keylen = 0;
486 	int	valuelen = 0;
487 	u32	buf_len;
488 	struct vmbus_channel *channel;
489 	u64	req_id;
490 	int ret;
491 
492 	/*
493 	 * Copy the global state for completing the transaction. Note that
494 	 * only one transaction can be active at a time.
495 	 */
496 
497 	buf_len = kvp_transaction.recv_len;
498 	channel = kvp_transaction.recv_channel;
499 	req_id = kvp_transaction.recv_req_id;
500 
501 	icmsghdrp = (struct icmsg_hdr *)
502 			&recv_buffer[sizeof(struct vmbuspipe_hdr)];
503 
504 	if (channel->onchannel_callback == NULL)
505 		/*
506 		 * We have raced with util driver being unloaded;
507 		 * silently return.
508 		 */
509 		return;
510 
511 	icmsghdrp->status = error;
512 
513 	/*
514 	 * If the error parameter is set, terminate the host's enumeration
515 	 * on this pool.
516 	 */
517 	if (error) {
518 		/*
519 		 * Something failed or we have timedout;
520 		 * terminate the current host-side iteration.
521 		 */
522 		goto response_done;
523 	}
524 
525 	kvp_msg = (struct hv_kvp_msg *)
526 			&recv_buffer[sizeof(struct vmbuspipe_hdr) +
527 			sizeof(struct icmsg_hdr)];
528 
529 	switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
530 	case KVP_OP_GET_IP_INFO:
531 		ret = process_ob_ipinfo(msg_to_host,
532 				 (struct hv_kvp_ip_msg *)kvp_msg,
533 				 KVP_OP_GET_IP_INFO);
534 		if (ret < 0)
535 			icmsghdrp->status = HV_E_FAIL;
536 
537 		goto response_done;
538 	case KVP_OP_SET_IP_INFO:
539 		goto response_done;
540 	case KVP_OP_GET:
541 		kvp_data = &kvp_msg->body.kvp_get.data;
542 		goto copy_value;
543 
544 	case KVP_OP_SET:
545 	case KVP_OP_DELETE:
546 		goto response_done;
547 
548 	default:
549 		break;
550 	}
551 
552 	kvp_data = &kvp_msg->body.kvp_enum_data.data;
553 	key_name = msg_to_host->body.kvp_enum_data.data.key;
554 
555 	/*
556 	 * The windows host expects the key/value pair to be encoded
557 	 * in utf16. Ensure that the key/value size reported to the host
558 	 * will be less than or equal to the MAX size (including the
559 	 * terminating character).
560 	 */
561 	keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
562 				(wchar_t *) kvp_data->key,
563 				(HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
564 	kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
565 
566 copy_value:
567 	value = msg_to_host->body.kvp_enum_data.data.value;
568 	valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
569 				(wchar_t *) kvp_data->value,
570 				(HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
571 	kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
572 
573 	/*
574 	 * If the utf8s to utf16s conversion failed; notify host
575 	 * of the error.
576 	 */
577 	if ((keylen < 0) || (valuelen < 0))
578 		icmsghdrp->status = HV_E_FAIL;
579 
580 	kvp_data->value_type = REG_SZ; /* all our values are strings */
581 
582 response_done:
583 	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
584 
585 	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
586 				VM_PKT_DATA_INBAND, 0);
587 }
588 
589 /*
590  * This callback is invoked when we get a KVP message from the host.
591  * The host ensures that only one KVP transaction can be active at a time.
592  * KVP implementation in Linux needs to forward the key to a user-mde
593  * component to retrive the corresponding value. Consequently, we cannot
594  * respond to the host in the conext of this callback. Since the host
595  * guarantees that at most only one transaction can be active at a time,
596  * we stash away the transaction state in a set of global variables.
597  */
598 
hv_kvp_onchannelcallback(void * context)599 void hv_kvp_onchannelcallback(void *context)
600 {
601 	struct vmbus_channel *channel = context;
602 	u32 recvlen;
603 	u64 requestid;
604 
605 	struct hv_kvp_msg *kvp_msg;
606 
607 	struct icmsg_hdr *icmsghdrp;
608 	struct icmsg_negotiate *negop = NULL;
609 	int util_fw_version;
610 	int kvp_srv_version;
611 	static enum {NEGO_NOT_STARTED,
612 		     NEGO_IN_PROGRESS,
613 		     NEGO_FINISHED} host_negotiatied = NEGO_NOT_STARTED;
614 
615 	if (kvp_transaction.state < HVUTIL_READY) {
616 		/*
617 		 * If userspace daemon is not connected and host is asking
618 		 * us to negotiate we need to delay to not lose messages.
619 		 * This is important for Failover IP setting.
620 		 */
621 		if (host_negotiatied == NEGO_NOT_STARTED) {
622 			host_negotiatied = NEGO_IN_PROGRESS;
623 			schedule_delayed_work(&kvp_host_handshake_work,
624 				      HV_UTIL_NEGO_TIMEOUT * HZ);
625 		}
626 		return;
627 	}
628 	if (kvp_transaction.state > HVUTIL_READY)
629 		return;
630 recheck:
631 	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen,
632 			 &requestid);
633 
634 	if (recvlen > 0) {
635 		icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
636 			sizeof(struct vmbuspipe_hdr)];
637 
638 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
639 			/*
640 			 * Based on the host, select appropriate
641 			 * framework and service versions we will
642 			 * negotiate.
643 			 */
644 			switch (vmbus_proto_version) {
645 			case (VERSION_WS2008):
646 				util_fw_version = UTIL_WS2K8_FW_VERSION;
647 				kvp_srv_version = WS2008_SRV_VERSION;
648 				break;
649 			case (VERSION_WIN7):
650 				util_fw_version = UTIL_FW_VERSION;
651 				kvp_srv_version = WIN7_SRV_VERSION;
652 				break;
653 			default:
654 				util_fw_version = UTIL_FW_VERSION;
655 				kvp_srv_version = WIN8_SRV_VERSION;
656 			}
657 			vmbus_prep_negotiate_resp(icmsghdrp, negop,
658 				 recv_buffer, util_fw_version,
659 				 kvp_srv_version);
660 
661 		} else {
662 			kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
663 				sizeof(struct vmbuspipe_hdr) +
664 				sizeof(struct icmsg_hdr)];
665 
666 			/*
667 			 * Stash away this global state for completing the
668 			 * transaction; note transactions are serialized.
669 			 */
670 
671 			kvp_transaction.recv_len = recvlen;
672 			kvp_transaction.recv_req_id = requestid;
673 			kvp_transaction.kvp_msg = kvp_msg;
674 
675 			if (kvp_transaction.state < HVUTIL_READY) {
676 				/* Userspace is not registered yet */
677 				kvp_respond_to_host(NULL, HV_E_FAIL);
678 				return;
679 			}
680 			kvp_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
681 
682 			/*
683 			 * Get the information from the
684 			 * user-mode component.
685 			 * component. This transaction will be
686 			 * completed when we get the value from
687 			 * the user-mode component.
688 			 * Set a timeout to deal with
689 			 * user-mode not responding.
690 			 */
691 			schedule_work(&kvp_sendkey_work);
692 			schedule_delayed_work(&kvp_timeout_work,
693 					      HV_UTIL_TIMEOUT * HZ);
694 
695 			return;
696 
697 		}
698 
699 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
700 			| ICMSGHDRFLAG_RESPONSE;
701 
702 		vmbus_sendpacket(channel, recv_buffer,
703 				       recvlen, requestid,
704 				       VM_PKT_DATA_INBAND, 0);
705 
706 		host_negotiatied = NEGO_FINISHED;
707 
708 		goto recheck;
709 	}
710 
711 }
712 
kvp_on_reset(void)713 static void kvp_on_reset(void)
714 {
715 	if (cancel_delayed_work_sync(&kvp_timeout_work))
716 		kvp_respond_to_host(NULL, HV_E_FAIL);
717 	kvp_transaction.state = HVUTIL_DEVICE_INIT;
718 	complete(&release_event);
719 }
720 
721 int
hv_kvp_init(struct hv_util_service * srv)722 hv_kvp_init(struct hv_util_service *srv)
723 {
724 	recv_buffer = srv->recv_buffer;
725 	kvp_transaction.recv_channel = srv->channel;
726 
727 	init_completion(&release_event);
728 	/*
729 	 * When this driver loads, the user level daemon that
730 	 * processes the host requests may not yet be running.
731 	 * Defer processing channel callbacks until the daemon
732 	 * has registered.
733 	 */
734 	kvp_transaction.state = HVUTIL_DEVICE_INIT;
735 
736 	hvt = hvutil_transport_init(kvp_devname, CN_KVP_IDX, CN_KVP_VAL,
737 				    kvp_on_msg, kvp_on_reset);
738 	if (!hvt)
739 		return -EFAULT;
740 
741 	return 0;
742 }
743 
hv_kvp_deinit(void)744 void hv_kvp_deinit(void)
745 {
746 	kvp_transaction.state = HVUTIL_DEVICE_DYING;
747 	cancel_delayed_work_sync(&kvp_host_handshake_work);
748 	cancel_delayed_work_sync(&kvp_timeout_work);
749 	cancel_work_sync(&kvp_sendkey_work);
750 	hvutil_transport_destroy(hvt);
751 	wait_for_completion(&release_event);
752 }
753