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v5.4
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * An implementation of file copy service.
  4 *
  5 * Copyright (C) 2014, Microsoft, Inc.
  6 *
  7 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
 
 
 
 
 
 
 
 
 
 
 
  8 */
  9
 10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 11
 12#include <linux/nls.h>
 13#include <linux/workqueue.h>
 14#include <linux/hyperv.h>
 15#include <linux/sched.h>
 16
 17#include "hyperv_vmbus.h"
 18#include "hv_utils_transport.h"
 19
 20#define WIN8_SRV_MAJOR		1
 21#define WIN8_SRV_MINOR		1
 22#define WIN8_SRV_VERSION	(WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
 23
 24#define FCOPY_VER_COUNT 1
 25static const int fcopy_versions[] = {
 26	WIN8_SRV_VERSION
 27};
 28
 29#define FW_VER_COUNT 1
 30static const int fw_versions[] = {
 31	UTIL_FW_VERSION
 32};
 33
 34/*
 35 * Global state maintained for transaction that is being processed.
 36 * For a class of integration services, including the "file copy service",
 37 * the specified protocol is a "request/response" protocol which means that
 38 * there can only be single outstanding transaction from the host at any
 39 * given point in time. We use this to simplify memory management in this
 40 * driver - we cache and process only one message at a time.
 41 *
 42 * While the request/response protocol is guaranteed by the host, we further
 43 * ensure this by serializing packet processing in this driver - we do not
 44 * read additional packets from the VMBUs until the current packet is fully
 45 * handled.
 46 */
 47
 48static struct {
 49	int state;   /* hvutil_device_state */
 50	int recv_len; /* number of bytes received. */
 51	struct hv_fcopy_hdr  *fcopy_msg; /* current message */
 52	struct vmbus_channel *recv_channel; /* chn we got the request */
 53	u64 recv_req_id; /* request ID. */
 54} fcopy_transaction;
 55
 56static void fcopy_respond_to_host(int error);
 57static void fcopy_send_data(struct work_struct *dummy);
 58static void fcopy_timeout_func(struct work_struct *dummy);
 59static DECLARE_DELAYED_WORK(fcopy_timeout_work, fcopy_timeout_func);
 60static DECLARE_WORK(fcopy_send_work, fcopy_send_data);
 61static const char fcopy_devname[] = "vmbus/hv_fcopy";
 62static u8 *recv_buffer;
 63static struct hvutil_transport *hvt;
 64/*
 65 * This state maintains the version number registered by the daemon.
 66 */
 67static int dm_reg_value;
 68
 69static void fcopy_poll_wrapper(void *channel)
 70{
 71	/* Transaction is finished, reset the state here to avoid races. */
 72	fcopy_transaction.state = HVUTIL_READY;
 73	hv_fcopy_onchannelcallback(channel);
 74}
 75
 76static void fcopy_timeout_func(struct work_struct *dummy)
 77{
 78	/*
 79	 * If the timer fires, the user-mode component has not responded;
 80	 * process the pending transaction.
 81	 */
 82	fcopy_respond_to_host(HV_E_FAIL);
 83	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
 84}
 85
 86static void fcopy_register_done(void)
 87{
 88	pr_debug("FCP: userspace daemon registered\n");
 89	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
 90}
 91
 92static int fcopy_handle_handshake(u32 version)
 93{
 94	u32 our_ver = FCOPY_CURRENT_VERSION;
 95
 96	switch (version) {
 97	case FCOPY_VERSION_0:
 98		/* Daemon doesn't expect us to reply */
 99		dm_reg_value = version;
100		break;
101	case FCOPY_VERSION_1:
102		/* Daemon expects us to reply with our own version */
103		if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver),
104		    fcopy_register_done))
105			return -EFAULT;
106		dm_reg_value = version;
107		break;
108	default:
109		/*
110		 * For now we will fail the registration.
111		 * If and when we have multiple versions to
112		 * deal with, we will be backward compatible.
113		 * We will add this code when needed.
114		 */
115		return -EINVAL;
116	}
117	pr_debug("FCP: userspace daemon ver. %d connected\n", version);
118	return 0;
119}
120
121static void fcopy_send_data(struct work_struct *dummy)
122{
123	struct hv_start_fcopy *smsg_out = NULL;
124	int operation = fcopy_transaction.fcopy_msg->operation;
125	struct hv_start_fcopy *smsg_in;
126	void *out_src;
127	int rc, out_len;
128
129	/*
130	 * The  strings sent from the host are encoded in
131	 * in utf16; convert it to utf8 strings.
132	 * The host assures us that the utf16 strings will not exceed
133	 * the max lengths specified. We will however, reserve room
134	 * for the string terminating character - in the utf16s_utf8s()
135	 * function we limit the size of the buffer where the converted
136	 * string is placed to W_MAX_PATH -1 to guarantee
137	 * that the strings can be properly terminated!
138	 */
139
140	switch (operation) {
141	case START_FILE_COPY:
142		out_len = sizeof(struct hv_start_fcopy);
143		smsg_out = kzalloc(sizeof(*smsg_out), GFP_KERNEL);
144		if (!smsg_out)
145			return;
146
147		smsg_out->hdr.operation = operation;
148		smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
149
150		utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
151				UTF16_LITTLE_ENDIAN,
152				(__u8 *)&smsg_out->file_name, W_MAX_PATH - 1);
153
154		utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
155				UTF16_LITTLE_ENDIAN,
156				(__u8 *)&smsg_out->path_name, W_MAX_PATH - 1);
157
158		smsg_out->copy_flags = smsg_in->copy_flags;
159		smsg_out->file_size = smsg_in->file_size;
160		out_src = smsg_out;
161		break;
162
163	case WRITE_TO_FILE:
164		out_src = fcopy_transaction.fcopy_msg;
165		out_len = sizeof(struct hv_do_fcopy);
166		break;
167	default:
168		out_src = fcopy_transaction.fcopy_msg;
169		out_len = fcopy_transaction.recv_len;
170		break;
171	}
172
173	fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
174	rc = hvutil_transport_send(hvt, out_src, out_len, NULL);
175	if (rc) {
176		pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
177		if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
178			fcopy_respond_to_host(HV_E_FAIL);
179			fcopy_transaction.state = HVUTIL_READY;
180		}
181	}
182	kfree(smsg_out);
183}
184
185/*
186 * Send a response back to the host.
187 */
188
189static void
190fcopy_respond_to_host(int error)
191{
192	struct icmsg_hdr *icmsghdr;
193	u32 buf_len;
194	struct vmbus_channel *channel;
195	u64 req_id;
196
197	/*
198	 * Copy the global state for completing the transaction. Note that
199	 * only one transaction can be active at a time. This is guaranteed
200	 * by the file copy protocol implemented by the host. Furthermore,
201	 * the "transaction active" state we maintain ensures that there can
202	 * only be one active transaction at a time.
203	 */
204
205	buf_len = fcopy_transaction.recv_len;
206	channel = fcopy_transaction.recv_channel;
207	req_id = fcopy_transaction.recv_req_id;
208
209	icmsghdr = (struct icmsg_hdr *)
210			&recv_buffer[sizeof(struct vmbuspipe_hdr)];
211
212	if (channel->onchannel_callback == NULL)
213		/*
214		 * We have raced with util driver being unloaded;
215		 * silently return.
216		 */
217		return;
218
219	icmsghdr->status = error;
220	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
221	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
222				VM_PKT_DATA_INBAND, 0);
223}
224
225void hv_fcopy_onchannelcallback(void *context)
226{
227	struct vmbus_channel *channel = context;
228	u32 recvlen;
229	u64 requestid;
230	struct hv_fcopy_hdr *fcopy_msg;
231	struct icmsg_hdr *icmsghdr;
232	int fcopy_srv_version;
233
234	if (fcopy_transaction.state > HVUTIL_READY)
235		return;
236
237	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
238			 &requestid);
239	if (recvlen <= 0)
240		return;
241
242	icmsghdr = (struct icmsg_hdr *)&recv_buffer[
243			sizeof(struct vmbuspipe_hdr)];
244	if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
245		if (vmbus_prep_negotiate_resp(icmsghdr, recv_buffer,
246				fw_versions, FW_VER_COUNT,
247				fcopy_versions, FCOPY_VER_COUNT,
248				NULL, &fcopy_srv_version)) {
249
250			pr_info("FCopy IC version %d.%d\n",
251				fcopy_srv_version >> 16,
252				fcopy_srv_version & 0xFFFF);
253		}
254	} else {
255		fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
256				sizeof(struct vmbuspipe_hdr) +
257				sizeof(struct icmsg_hdr)];
258
259		/*
260		 * Stash away this global state for completing the
261		 * transaction; note transactions are serialized.
262		 */
263
264		fcopy_transaction.recv_len = recvlen;
265		fcopy_transaction.recv_req_id = requestid;
266		fcopy_transaction.fcopy_msg = fcopy_msg;
267
268		if (fcopy_transaction.state < HVUTIL_READY) {
269			/* Userspace is not registered yet */
270			fcopy_respond_to_host(HV_E_FAIL);
271			return;
272		}
273		fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
274
275		/*
276		 * Send the information to the user-level daemon.
277		 */
278		schedule_work(&fcopy_send_work);
279		schedule_delayed_work(&fcopy_timeout_work,
280				      HV_UTIL_TIMEOUT * HZ);
281		return;
282	}
283	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
284	vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
285			VM_PKT_DATA_INBAND, 0);
286}
287
288/* Callback when data is received from userspace */
289static int fcopy_on_msg(void *msg, int len)
290{
291	int *val = (int *)msg;
292
293	if (len != sizeof(int))
294		return -EINVAL;
295
296	if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
297		return fcopy_handle_handshake(*val);
298
299	if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
300		return -EINVAL;
301
302	/*
303	 * Complete the transaction by forwarding the result
304	 * to the host. But first, cancel the timeout.
305	 */
306	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
307		fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
308		fcopy_respond_to_host(*val);
309		hv_poll_channel(fcopy_transaction.recv_channel,
310				fcopy_poll_wrapper);
311	}
312
313	return 0;
314}
315
316static void fcopy_on_reset(void)
317{
318	/*
319	 * The daemon has exited; reset the state.
320	 */
321	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
322
323	if (cancel_delayed_work_sync(&fcopy_timeout_work))
324		fcopy_respond_to_host(HV_E_FAIL);
325}
326
327int hv_fcopy_init(struct hv_util_service *srv)
328{
329	recv_buffer = srv->recv_buffer;
330	fcopy_transaction.recv_channel = srv->channel;
331
332	/*
333	 * When this driver loads, the user level daemon that
334	 * processes the host requests may not yet be running.
335	 * Defer processing channel callbacks until the daemon
336	 * has registered.
337	 */
338	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
339
340	hvt = hvutil_transport_init(fcopy_devname, 0, 0,
341				    fcopy_on_msg, fcopy_on_reset);
342	if (!hvt)
343		return -EFAULT;
344
345	return 0;
346}
347
348void hv_fcopy_deinit(void)
349{
350	fcopy_transaction.state = HVUTIL_DEVICE_DYING;
351	cancel_delayed_work_sync(&fcopy_timeout_work);
352	hvutil_transport_destroy(hvt);
353}
v4.17
 
  1/*
  2 * An implementation of file copy service.
  3 *
  4 * Copyright (C) 2014, Microsoft, Inc.
  5 *
  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 */
 19
 20#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 21
 22#include <linux/nls.h>
 23#include <linux/workqueue.h>
 24#include <linux/hyperv.h>
 25#include <linux/sched.h>
 26
 27#include "hyperv_vmbus.h"
 28#include "hv_utils_transport.h"
 29
 30#define WIN8_SRV_MAJOR		1
 31#define WIN8_SRV_MINOR		1
 32#define WIN8_SRV_VERSION	(WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
 33
 34#define FCOPY_VER_COUNT 1
 35static const int fcopy_versions[] = {
 36	WIN8_SRV_VERSION
 37};
 38
 39#define FW_VER_COUNT 1
 40static const int fw_versions[] = {
 41	UTIL_FW_VERSION
 42};
 43
 44/*
 45 * Global state maintained for transaction that is being processed.
 46 * For a class of integration services, including the "file copy service",
 47 * the specified protocol is a "request/response" protocol which means that
 48 * there can only be single outstanding transaction from the host at any
 49 * given point in time. We use this to simplify memory management in this
 50 * driver - we cache and process only one message at a time.
 51 *
 52 * While the request/response protocol is guaranteed by the host, we further
 53 * ensure this by serializing packet processing in this driver - we do not
 54 * read additional packets from the VMBUs until the current packet is fully
 55 * handled.
 56 */
 57
 58static struct {
 59	int state;   /* hvutil_device_state */
 60	int recv_len; /* number of bytes received. */
 61	struct hv_fcopy_hdr  *fcopy_msg; /* current message */
 62	struct vmbus_channel *recv_channel; /* chn we got the request */
 63	u64 recv_req_id; /* request ID. */
 64} fcopy_transaction;
 65
 66static void fcopy_respond_to_host(int error);
 67static void fcopy_send_data(struct work_struct *dummy);
 68static void fcopy_timeout_func(struct work_struct *dummy);
 69static DECLARE_DELAYED_WORK(fcopy_timeout_work, fcopy_timeout_func);
 70static DECLARE_WORK(fcopy_send_work, fcopy_send_data);
 71static const char fcopy_devname[] = "vmbus/hv_fcopy";
 72static u8 *recv_buffer;
 73static struct hvutil_transport *hvt;
 74/*
 75 * This state maintains the version number registered by the daemon.
 76 */
 77static int dm_reg_value;
 78
 79static void fcopy_poll_wrapper(void *channel)
 80{
 81	/* Transaction is finished, reset the state here to avoid races. */
 82	fcopy_transaction.state = HVUTIL_READY;
 83	hv_fcopy_onchannelcallback(channel);
 84}
 85
 86static void fcopy_timeout_func(struct work_struct *dummy)
 87{
 88	/*
 89	 * If the timer fires, the user-mode component has not responded;
 90	 * process the pending transaction.
 91	 */
 92	fcopy_respond_to_host(HV_E_FAIL);
 93	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
 94}
 95
 96static void fcopy_register_done(void)
 97{
 98	pr_debug("FCP: userspace daemon registered\n");
 99	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
100}
101
102static int fcopy_handle_handshake(u32 version)
103{
104	u32 our_ver = FCOPY_CURRENT_VERSION;
105
106	switch (version) {
107	case FCOPY_VERSION_0:
108		/* Daemon doesn't expect us to reply */
109		dm_reg_value = version;
110		break;
111	case FCOPY_VERSION_1:
112		/* Daemon expects us to reply with our own version */
113		if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver),
114		    fcopy_register_done))
115			return -EFAULT;
116		dm_reg_value = version;
117		break;
118	default:
119		/*
120		 * For now we will fail the registration.
121		 * If and when we have multiple versions to
122		 * deal with, we will be backward compatible.
123		 * We will add this code when needed.
124		 */
125		return -EINVAL;
126	}
127	pr_debug("FCP: userspace daemon ver. %d connected\n", version);
128	return 0;
129}
130
131static void fcopy_send_data(struct work_struct *dummy)
132{
133	struct hv_start_fcopy *smsg_out = NULL;
134	int operation = fcopy_transaction.fcopy_msg->operation;
135	struct hv_start_fcopy *smsg_in;
136	void *out_src;
137	int rc, out_len;
138
139	/*
140	 * The  strings sent from the host are encoded in
141	 * in utf16; convert it to utf8 strings.
142	 * The host assures us that the utf16 strings will not exceed
143	 * the max lengths specified. We will however, reserve room
144	 * for the string terminating character - in the utf16s_utf8s()
145	 * function we limit the size of the buffer where the converted
146	 * string is placed to W_MAX_PATH -1 to guarantee
147	 * that the strings can be properly terminated!
148	 */
149
150	switch (operation) {
151	case START_FILE_COPY:
152		out_len = sizeof(struct hv_start_fcopy);
153		smsg_out = kzalloc(sizeof(*smsg_out), GFP_KERNEL);
154		if (!smsg_out)
155			return;
156
157		smsg_out->hdr.operation = operation;
158		smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
159
160		utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
161				UTF16_LITTLE_ENDIAN,
162				(__u8 *)&smsg_out->file_name, W_MAX_PATH - 1);
163
164		utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
165				UTF16_LITTLE_ENDIAN,
166				(__u8 *)&smsg_out->path_name, W_MAX_PATH - 1);
167
168		smsg_out->copy_flags = smsg_in->copy_flags;
169		smsg_out->file_size = smsg_in->file_size;
170		out_src = smsg_out;
171		break;
172
173	case WRITE_TO_FILE:
174		out_src = fcopy_transaction.fcopy_msg;
175		out_len = sizeof(struct hv_do_fcopy);
176		break;
177	default:
178		out_src = fcopy_transaction.fcopy_msg;
179		out_len = fcopy_transaction.recv_len;
180		break;
181	}
182
183	fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
184	rc = hvutil_transport_send(hvt, out_src, out_len, NULL);
185	if (rc) {
186		pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
187		if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
188			fcopy_respond_to_host(HV_E_FAIL);
189			fcopy_transaction.state = HVUTIL_READY;
190		}
191	}
192	kfree(smsg_out);
193}
194
195/*
196 * Send a response back to the host.
197 */
198
199static void
200fcopy_respond_to_host(int error)
201{
202	struct icmsg_hdr *icmsghdr;
203	u32 buf_len;
204	struct vmbus_channel *channel;
205	u64 req_id;
206
207	/*
208	 * Copy the global state for completing the transaction. Note that
209	 * only one transaction can be active at a time. This is guaranteed
210	 * by the file copy protocol implemented by the host. Furthermore,
211	 * the "transaction active" state we maintain ensures that there can
212	 * only be one active transaction at a time.
213	 */
214
215	buf_len = fcopy_transaction.recv_len;
216	channel = fcopy_transaction.recv_channel;
217	req_id = fcopy_transaction.recv_req_id;
218
219	icmsghdr = (struct icmsg_hdr *)
220			&recv_buffer[sizeof(struct vmbuspipe_hdr)];
221
222	if (channel->onchannel_callback == NULL)
223		/*
224		 * We have raced with util driver being unloaded;
225		 * silently return.
226		 */
227		return;
228
229	icmsghdr->status = error;
230	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
231	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
232				VM_PKT_DATA_INBAND, 0);
233}
234
235void hv_fcopy_onchannelcallback(void *context)
236{
237	struct vmbus_channel *channel = context;
238	u32 recvlen;
239	u64 requestid;
240	struct hv_fcopy_hdr *fcopy_msg;
241	struct icmsg_hdr *icmsghdr;
242	int fcopy_srv_version;
243
244	if (fcopy_transaction.state > HVUTIL_READY)
245		return;
246
247	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
248			 &requestid);
249	if (recvlen <= 0)
250		return;
251
252	icmsghdr = (struct icmsg_hdr *)&recv_buffer[
253			sizeof(struct vmbuspipe_hdr)];
254	if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
255		if (vmbus_prep_negotiate_resp(icmsghdr, recv_buffer,
256				fw_versions, FW_VER_COUNT,
257				fcopy_versions, FCOPY_VER_COUNT,
258				NULL, &fcopy_srv_version)) {
259
260			pr_info("FCopy IC version %d.%d\n",
261				fcopy_srv_version >> 16,
262				fcopy_srv_version & 0xFFFF);
263		}
264	} else {
265		fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
266				sizeof(struct vmbuspipe_hdr) +
267				sizeof(struct icmsg_hdr)];
268
269		/*
270		 * Stash away this global state for completing the
271		 * transaction; note transactions are serialized.
272		 */
273
274		fcopy_transaction.recv_len = recvlen;
275		fcopy_transaction.recv_req_id = requestid;
276		fcopy_transaction.fcopy_msg = fcopy_msg;
277
278		if (fcopy_transaction.state < HVUTIL_READY) {
279			/* Userspace is not registered yet */
280			fcopy_respond_to_host(HV_E_FAIL);
281			return;
282		}
283		fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
284
285		/*
286		 * Send the information to the user-level daemon.
287		 */
288		schedule_work(&fcopy_send_work);
289		schedule_delayed_work(&fcopy_timeout_work,
290				      HV_UTIL_TIMEOUT * HZ);
291		return;
292	}
293	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
294	vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
295			VM_PKT_DATA_INBAND, 0);
296}
297
298/* Callback when data is received from userspace */
299static int fcopy_on_msg(void *msg, int len)
300{
301	int *val = (int *)msg;
302
303	if (len != sizeof(int))
304		return -EINVAL;
305
306	if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
307		return fcopy_handle_handshake(*val);
308
309	if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
310		return -EINVAL;
311
312	/*
313	 * Complete the transaction by forwarding the result
314	 * to the host. But first, cancel the timeout.
315	 */
316	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
317		fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
318		fcopy_respond_to_host(*val);
319		hv_poll_channel(fcopy_transaction.recv_channel,
320				fcopy_poll_wrapper);
321	}
322
323	return 0;
324}
325
326static void fcopy_on_reset(void)
327{
328	/*
329	 * The daemon has exited; reset the state.
330	 */
331	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
332
333	if (cancel_delayed_work_sync(&fcopy_timeout_work))
334		fcopy_respond_to_host(HV_E_FAIL);
335}
336
337int hv_fcopy_init(struct hv_util_service *srv)
338{
339	recv_buffer = srv->recv_buffer;
340	fcopy_transaction.recv_channel = srv->channel;
341
342	/*
343	 * When this driver loads, the user level daemon that
344	 * processes the host requests may not yet be running.
345	 * Defer processing channel callbacks until the daemon
346	 * has registered.
347	 */
348	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
349
350	hvt = hvutil_transport_init(fcopy_devname, 0, 0,
351				    fcopy_on_msg, fcopy_on_reset);
352	if (!hvt)
353		return -EFAULT;
354
355	return 0;
356}
357
358void hv_fcopy_deinit(void)
359{
360	fcopy_transaction.state = HVUTIL_DEVICE_DYING;
361	cancel_delayed_work_sync(&fcopy_timeout_work);
362	hvutil_transport_destroy(hvt);
363}