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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/semaphore.h>
23#include <linux/fs.h>
24#include <linux/nls.h>
25#include <linux/workqueue.h>
26#include <linux/cdev.h>
27#include <linux/hyperv.h>
28#include <linux/sched.h>
29#include <linux/uaccess.h>
30#include <linux/miscdevice.h>
31
32#include "hyperv_vmbus.h"
33
34#define WIN8_SRV_MAJOR 1
35#define WIN8_SRV_MINOR 1
36#define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
37
38/*
39 * Global state maintained for transaction that is being processed.
40 * For a class of integration services, including the "file copy service",
41 * the specified protocol is a "request/response" protocol which means that
42 * there can only be single outstanding transaction from the host at any
43 * given point in time. We use this to simplify memory management in this
44 * driver - we cache and process only one message at a time.
45 *
46 * While the request/response protocol is guaranteed by the host, we further
47 * ensure this by serializing packet processing in this driver - we do not
48 * read additional packets from the VMBUs until the current packet is fully
49 * handled.
50 *
51 * The transaction "active" state is set when we receive a request from the
52 * host and we cleanup this state when the transaction is completed - when we
53 * respond to the host with our response. When the transaction active state is
54 * set, we defer handling incoming packets.
55 */
56
57static struct {
58 bool active; /* transaction status - active or not */
59 int recv_len; /* number of bytes received. */
60 struct hv_fcopy_hdr *fcopy_msg; /* current message */
61 struct hv_start_fcopy message; /* sent to daemon */
62 struct vmbus_channel *recv_channel; /* chn we got the request */
63 u64 recv_req_id; /* request ID. */
64 void *fcopy_context; /* for the channel callback */
65 struct semaphore read_sema;
66} fcopy_transaction;
67
68static bool opened; /* currently device opened */
69
70/*
71 * Before we can accept copy messages from the host, we need
72 * to handshake with the user level daemon. This state tracks
73 * if we are in the handshake phase.
74 */
75static bool in_hand_shake = true;
76static void fcopy_send_data(void);
77static void fcopy_respond_to_host(int error);
78static void fcopy_work_func(struct work_struct *dummy);
79static DECLARE_DELAYED_WORK(fcopy_work, fcopy_work_func);
80static u8 *recv_buffer;
81
82static void fcopy_work_func(struct work_struct *dummy)
83{
84 /*
85 * If the timer fires, the user-mode component has not responded;
86 * process the pending transaction.
87 */
88 fcopy_respond_to_host(HV_E_FAIL);
89}
90
91static int fcopy_handle_handshake(u32 version)
92{
93 switch (version) {
94 case FCOPY_CURRENT_VERSION:
95 break;
96 default:
97 /*
98 * For now we will fail the registration.
99 * If and when we have multiple versions to
100 * deal with, we will be backward compatible.
101 * We will add this code when needed.
102 */
103 return -EINVAL;
104 }
105 pr_info("FCP: user-mode registering done. Daemon version: %d\n",
106 version);
107 fcopy_transaction.active = false;
108 if (fcopy_transaction.fcopy_context)
109 hv_fcopy_onchannelcallback(fcopy_transaction.fcopy_context);
110 in_hand_shake = false;
111 return 0;
112}
113
114static void fcopy_send_data(void)
115{
116 struct hv_start_fcopy *smsg_out = &fcopy_transaction.message;
117 int operation = fcopy_transaction.fcopy_msg->operation;
118 struct hv_start_fcopy *smsg_in;
119
120 /*
121 * The strings sent from the host are encoded in
122 * in utf16; convert it to utf8 strings.
123 * The host assures us that the utf16 strings will not exceed
124 * the max lengths specified. We will however, reserve room
125 * for the string terminating character - in the utf16s_utf8s()
126 * function we limit the size of the buffer where the converted
127 * string is placed to W_MAX_PATH -1 to guarantee
128 * that the strings can be properly terminated!
129 */
130
131 switch (operation) {
132 case START_FILE_COPY:
133 memset(smsg_out, 0, sizeof(struct hv_start_fcopy));
134 smsg_out->hdr.operation = operation;
135 smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
136
137 utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
138 UTF16_LITTLE_ENDIAN,
139 (__u8 *)smsg_out->file_name, W_MAX_PATH - 1);
140
141 utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
142 UTF16_LITTLE_ENDIAN,
143 (__u8 *)smsg_out->path_name, W_MAX_PATH - 1);
144
145 smsg_out->copy_flags = smsg_in->copy_flags;
146 smsg_out->file_size = smsg_in->file_size;
147 break;
148
149 default:
150 break;
151 }
152 up(&fcopy_transaction.read_sema);
153 return;
154}
155
156/*
157 * Send a response back to the host.
158 */
159
160static void
161fcopy_respond_to_host(int error)
162{
163 struct icmsg_hdr *icmsghdr;
164 u32 buf_len;
165 struct vmbus_channel *channel;
166 u64 req_id;
167
168 /*
169 * Copy the global state for completing the transaction. Note that
170 * only one transaction can be active at a time. This is guaranteed
171 * by the file copy protocol implemented by the host. Furthermore,
172 * the "transaction active" state we maintain ensures that there can
173 * only be one active transaction at a time.
174 */
175
176 buf_len = fcopy_transaction.recv_len;
177 channel = fcopy_transaction.recv_channel;
178 req_id = fcopy_transaction.recv_req_id;
179
180 fcopy_transaction.active = false;
181
182 icmsghdr = (struct icmsg_hdr *)
183 &recv_buffer[sizeof(struct vmbuspipe_hdr)];
184
185 if (channel->onchannel_callback == NULL)
186 /*
187 * We have raced with util driver being unloaded;
188 * silently return.
189 */
190 return;
191
192 icmsghdr->status = error;
193 icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
194 vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
195 VM_PKT_DATA_INBAND, 0);
196}
197
198void hv_fcopy_onchannelcallback(void *context)
199{
200 struct vmbus_channel *channel = context;
201 u32 recvlen;
202 u64 requestid;
203 struct hv_fcopy_hdr *fcopy_msg;
204 struct icmsg_hdr *icmsghdr;
205 struct icmsg_negotiate *negop = NULL;
206 int util_fw_version;
207 int fcopy_srv_version;
208
209 if (fcopy_transaction.active) {
210 /*
211 * We will defer processing this callback once
212 * the current transaction is complete.
213 */
214 fcopy_transaction.fcopy_context = context;
215 return;
216 }
217
218 vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
219 &requestid);
220 if (recvlen <= 0)
221 return;
222
223 icmsghdr = (struct icmsg_hdr *)&recv_buffer[
224 sizeof(struct vmbuspipe_hdr)];
225 if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
226 util_fw_version = UTIL_FW_VERSION;
227 fcopy_srv_version = WIN8_SRV_VERSION;
228 vmbus_prep_negotiate_resp(icmsghdr, negop, recv_buffer,
229 util_fw_version, fcopy_srv_version);
230 } else {
231 fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
232 sizeof(struct vmbuspipe_hdr) +
233 sizeof(struct icmsg_hdr)];
234
235 /*
236 * Stash away this global state for completing the
237 * transaction; note transactions are serialized.
238 */
239
240 fcopy_transaction.active = true;
241 fcopy_transaction.recv_len = recvlen;
242 fcopy_transaction.recv_channel = channel;
243 fcopy_transaction.recv_req_id = requestid;
244 fcopy_transaction.fcopy_msg = fcopy_msg;
245
246 /*
247 * Send the information to the user-level daemon.
248 */
249 fcopy_send_data();
250 schedule_delayed_work(&fcopy_work, 5*HZ);
251 return;
252 }
253 icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
254 vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
255 VM_PKT_DATA_INBAND, 0);
256}
257
258/*
259 * Create a char device that can support read/write for passing
260 * the payload.
261 */
262
263static ssize_t fcopy_read(struct file *file, char __user *buf,
264 size_t count, loff_t *ppos)
265{
266 void *src;
267 size_t copy_size;
268 int operation;
269
270 /*
271 * Wait until there is something to be read.
272 */
273 if (down_interruptible(&fcopy_transaction.read_sema))
274 return -EINTR;
275
276 /*
277 * The channel may be rescinded and in this case, we will wakeup the
278 * the thread blocked on the semaphore and we will use the opened
279 * state to correctly handle this case.
280 */
281 if (!opened)
282 return -ENODEV;
283
284 operation = fcopy_transaction.fcopy_msg->operation;
285
286 if (operation == START_FILE_COPY) {
287 src = &fcopy_transaction.message;
288 copy_size = sizeof(struct hv_start_fcopy);
289 if (count < copy_size)
290 return 0;
291 } else {
292 src = fcopy_transaction.fcopy_msg;
293 copy_size = sizeof(struct hv_do_fcopy);
294 if (count < copy_size)
295 return 0;
296 }
297 if (copy_to_user(buf, src, copy_size))
298 return -EFAULT;
299
300 return copy_size;
301}
302
303static ssize_t fcopy_write(struct file *file, const char __user *buf,
304 size_t count, loff_t *ppos)
305{
306 int response = 0;
307
308 if (count != sizeof(int))
309 return -EINVAL;
310
311 if (copy_from_user(&response, buf, sizeof(int)))
312 return -EFAULT;
313
314 if (in_hand_shake) {
315 if (fcopy_handle_handshake(response))
316 return -EINVAL;
317 return sizeof(int);
318 }
319
320 /*
321 * Complete the transaction by forwarding the result
322 * to the host. But first, cancel the timeout.
323 */
324 if (cancel_delayed_work_sync(&fcopy_work))
325 fcopy_respond_to_host(response);
326
327 return sizeof(int);
328}
329
330static int fcopy_open(struct inode *inode, struct file *f)
331{
332 /*
333 * The user level daemon that will open this device is
334 * really an extension of this driver. We can have only
335 * active open at a time.
336 */
337 if (opened)
338 return -EBUSY;
339
340 /*
341 * The daemon is alive; setup the state.
342 */
343 opened = true;
344 return 0;
345}
346
347static int fcopy_release(struct inode *inode, struct file *f)
348{
349 /*
350 * The daemon has exited; reset the state.
351 */
352 in_hand_shake = true;
353 opened = false;
354 return 0;
355}
356
357
358static const struct file_operations fcopy_fops = {
359 .read = fcopy_read,
360 .write = fcopy_write,
361 .release = fcopy_release,
362 .open = fcopy_open,
363};
364
365static struct miscdevice fcopy_misc = {
366 .minor = MISC_DYNAMIC_MINOR,
367 .name = "vmbus/hv_fcopy",
368 .fops = &fcopy_fops,
369};
370
371static int fcopy_dev_init(void)
372{
373 return misc_register(&fcopy_misc);
374}
375
376static void fcopy_dev_deinit(void)
377{
378
379 /*
380 * The device is going away - perhaps because the
381 * host has rescinded the channel. Setup state so that
382 * user level daemon can gracefully exit if it is blocked
383 * on the read semaphore.
384 */
385 opened = false;
386 /*
387 * Signal the semaphore as the device is
388 * going away.
389 */
390 up(&fcopy_transaction.read_sema);
391 misc_deregister(&fcopy_misc);
392}
393
394int hv_fcopy_init(struct hv_util_service *srv)
395{
396 recv_buffer = srv->recv_buffer;
397
398 /*
399 * When this driver loads, the user level daemon that
400 * processes the host requests may not yet be running.
401 * Defer processing channel callbacks until the daemon
402 * has registered.
403 */
404 fcopy_transaction.active = true;
405 sema_init(&fcopy_transaction.read_sema, 0);
406
407 return fcopy_dev_init();
408}
409
410void hv_fcopy_deinit(void)
411{
412 cancel_delayed_work_sync(&fcopy_work);
413 fcopy_dev_deinit();
414}
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#include <asm/hyperv-tlfs.h>
17
18#include "hyperv_vmbus.h"
19#include "hv_utils_transport.h"
20
21#define WIN8_SRV_MAJOR 1
22#define WIN8_SRV_MINOR 1
23#define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
24
25#define FCOPY_VER_COUNT 1
26static const int fcopy_versions[] = {
27 WIN8_SRV_VERSION
28};
29
30#define FW_VER_COUNT 1
31static const int fw_versions[] = {
32 UTIL_FW_VERSION
33};
34
35/*
36 * Global state maintained for transaction that is being processed.
37 * For a class of integration services, including the "file copy service",
38 * the specified protocol is a "request/response" protocol which means that
39 * there can only be single outstanding transaction from the host at any
40 * given point in time. We use this to simplify memory management in this
41 * driver - we cache and process only one message at a time.
42 *
43 * While the request/response protocol is guaranteed by the host, we further
44 * ensure this by serializing packet processing in this driver - we do not
45 * read additional packets from the VMBUs until the current packet is fully
46 * handled.
47 */
48
49static struct {
50 int state; /* hvutil_device_state */
51 int recv_len; /* number of bytes received. */
52 struct hv_fcopy_hdr *fcopy_msg; /* current message */
53 struct vmbus_channel *recv_channel; /* chn we got the request */
54 u64 recv_req_id; /* request ID. */
55} fcopy_transaction;
56
57static void fcopy_respond_to_host(int error);
58static void fcopy_send_data(struct work_struct *dummy);
59static void fcopy_timeout_func(struct work_struct *dummy);
60static DECLARE_DELAYED_WORK(fcopy_timeout_work, fcopy_timeout_func);
61static DECLARE_WORK(fcopy_send_work, fcopy_send_data);
62static const char fcopy_devname[] = "vmbus/hv_fcopy";
63static u8 *recv_buffer;
64static struct hvutil_transport *hvt;
65/*
66 * This state maintains the version number registered by the daemon.
67 */
68static int dm_reg_value;
69
70static void fcopy_poll_wrapper(void *channel)
71{
72 /* Transaction is finished, reset the state here to avoid races. */
73 fcopy_transaction.state = HVUTIL_READY;
74 tasklet_schedule(&((struct vmbus_channel *)channel)->callback_event);
75}
76
77static void fcopy_timeout_func(struct work_struct *dummy)
78{
79 /*
80 * If the timer fires, the user-mode component has not responded;
81 * process the pending transaction.
82 */
83 fcopy_respond_to_host(HV_E_FAIL);
84 hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
85}
86
87static void fcopy_register_done(void)
88{
89 pr_debug("FCP: userspace daemon registered\n");
90 hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
91}
92
93static int fcopy_handle_handshake(u32 version)
94{
95 u32 our_ver = FCOPY_CURRENT_VERSION;
96
97 switch (version) {
98 case FCOPY_VERSION_0:
99 /* Daemon doesn't expect us to reply */
100 dm_reg_value = version;
101 break;
102 case FCOPY_VERSION_1:
103 /* Daemon expects us to reply with our own version */
104 if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver),
105 fcopy_register_done))
106 return -EFAULT;
107 dm_reg_value = version;
108 break;
109 default:
110 /*
111 * For now we will fail the registration.
112 * If and when we have multiple versions to
113 * deal with, we will be backward compatible.
114 * We will add this code when needed.
115 */
116 return -EINVAL;
117 }
118 pr_debug("FCP: userspace daemon ver. %d connected\n", version);
119 return 0;
120}
121
122static void fcopy_send_data(struct work_struct *dummy)
123{
124 struct hv_start_fcopy *smsg_out = NULL;
125 int operation = fcopy_transaction.fcopy_msg->operation;
126 struct hv_start_fcopy *smsg_in;
127 void *out_src;
128 int rc, out_len;
129
130 /*
131 * The strings sent from the host are encoded in
132 * utf16; convert it to utf8 strings.
133 * The host assures us that the utf16 strings will not exceed
134 * the max lengths specified. We will however, reserve room
135 * for the string terminating character - in the utf16s_utf8s()
136 * function we limit the size of the buffer where the converted
137 * string is placed to W_MAX_PATH -1 to guarantee
138 * that the strings can be properly terminated!
139 */
140
141 switch (operation) {
142 case START_FILE_COPY:
143 out_len = sizeof(struct hv_start_fcopy);
144 smsg_out = kzalloc(sizeof(*smsg_out), GFP_KERNEL);
145 if (!smsg_out)
146 return;
147
148 smsg_out->hdr.operation = operation;
149 smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
150
151 utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
152 UTF16_LITTLE_ENDIAN,
153 (__u8 *)&smsg_out->file_name, W_MAX_PATH - 1);
154
155 utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
156 UTF16_LITTLE_ENDIAN,
157 (__u8 *)&smsg_out->path_name, W_MAX_PATH - 1);
158
159 smsg_out->copy_flags = smsg_in->copy_flags;
160 smsg_out->file_size = smsg_in->file_size;
161 out_src = smsg_out;
162 break;
163
164 case WRITE_TO_FILE:
165 out_src = fcopy_transaction.fcopy_msg;
166 out_len = sizeof(struct hv_do_fcopy);
167 break;
168 default:
169 out_src = fcopy_transaction.fcopy_msg;
170 out_len = fcopy_transaction.recv_len;
171 break;
172 }
173
174 fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
175 rc = hvutil_transport_send(hvt, out_src, out_len, NULL);
176 if (rc) {
177 pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
178 if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
179 fcopy_respond_to_host(HV_E_FAIL);
180 fcopy_transaction.state = HVUTIL_READY;
181 }
182 }
183 kfree(smsg_out);
184}
185
186/*
187 * Send a response back to the host.
188 */
189
190static void
191fcopy_respond_to_host(int error)
192{
193 struct icmsg_hdr *icmsghdr;
194 u32 buf_len;
195 struct vmbus_channel *channel;
196 u64 req_id;
197
198 /*
199 * Copy the global state for completing the transaction. Note that
200 * only one transaction can be active at a time. This is guaranteed
201 * by the file copy protocol implemented by the host. Furthermore,
202 * the "transaction active" state we maintain ensures that there can
203 * only be one active transaction at a time.
204 */
205
206 buf_len = fcopy_transaction.recv_len;
207 channel = fcopy_transaction.recv_channel;
208 req_id = fcopy_transaction.recv_req_id;
209
210 icmsghdr = (struct icmsg_hdr *)
211 &recv_buffer[sizeof(struct vmbuspipe_hdr)];
212
213 if (channel->onchannel_callback == NULL)
214 /*
215 * We have raced with util driver being unloaded;
216 * silently return.
217 */
218 return;
219
220 icmsghdr->status = error;
221 icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
222 vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
223 VM_PKT_DATA_INBAND, 0);
224}
225
226void hv_fcopy_onchannelcallback(void *context)
227{
228 struct vmbus_channel *channel = context;
229 u32 recvlen;
230 u64 requestid;
231 struct hv_fcopy_hdr *fcopy_msg;
232 struct icmsg_hdr *icmsghdr;
233 int fcopy_srv_version;
234
235 if (fcopy_transaction.state > HVUTIL_READY)
236 return;
237
238 if (vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 2, &recvlen, &requestid)) {
239 pr_err_ratelimited("Fcopy request received. Could not read into recv buf\n");
240 return;
241 }
242
243 if (!recvlen)
244 return;
245
246 /* Ensure recvlen is big enough to read header data */
247 if (recvlen < ICMSG_HDR) {
248 pr_err_ratelimited("Fcopy request received. Packet length too small: %d\n",
249 recvlen);
250 return;
251 }
252
253 icmsghdr = (struct icmsg_hdr *)&recv_buffer[
254 sizeof(struct vmbuspipe_hdr)];
255
256 if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
257 if (vmbus_prep_negotiate_resp(icmsghdr,
258 recv_buffer, recvlen,
259 fw_versions, FW_VER_COUNT,
260 fcopy_versions, FCOPY_VER_COUNT,
261 NULL, &fcopy_srv_version)) {
262
263 pr_info("FCopy IC version %d.%d\n",
264 fcopy_srv_version >> 16,
265 fcopy_srv_version & 0xFFFF);
266 }
267 } else if (icmsghdr->icmsgtype == ICMSGTYPE_FCOPY) {
268 /* Ensure recvlen is big enough to contain hv_fcopy_hdr */
269 if (recvlen < ICMSG_HDR + sizeof(struct hv_fcopy_hdr)) {
270 pr_err_ratelimited("Invalid Fcopy hdr. Packet length too small: %u\n",
271 recvlen);
272 return;
273 }
274 fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[ICMSG_HDR];
275
276 /*
277 * Stash away this global state for completing the
278 * transaction; note transactions are serialized.
279 */
280
281 fcopy_transaction.recv_len = recvlen;
282 fcopy_transaction.recv_req_id = requestid;
283 fcopy_transaction.fcopy_msg = fcopy_msg;
284
285 if (fcopy_transaction.state < HVUTIL_READY) {
286 /* Userspace is not registered yet */
287 fcopy_respond_to_host(HV_E_FAIL);
288 return;
289 }
290 fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
291
292 /*
293 * Send the information to the user-level daemon.
294 */
295 schedule_work(&fcopy_send_work);
296 schedule_delayed_work(&fcopy_timeout_work,
297 HV_UTIL_TIMEOUT * HZ);
298 return;
299 } else {
300 pr_err_ratelimited("Fcopy request received. Invalid msg type: %d\n",
301 icmsghdr->icmsgtype);
302 return;
303 }
304 icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
305 vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
306 VM_PKT_DATA_INBAND, 0);
307}
308
309/* Callback when data is received from userspace */
310static int fcopy_on_msg(void *msg, int len)
311{
312 int *val = (int *)msg;
313
314 if (len != sizeof(int))
315 return -EINVAL;
316
317 if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
318 return fcopy_handle_handshake(*val);
319
320 if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
321 return -EINVAL;
322
323 /*
324 * Complete the transaction by forwarding the result
325 * to the host. But first, cancel the timeout.
326 */
327 if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
328 fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
329 fcopy_respond_to_host(*val);
330 hv_poll_channel(fcopy_transaction.recv_channel,
331 fcopy_poll_wrapper);
332 }
333
334 return 0;
335}
336
337static void fcopy_on_reset(void)
338{
339 /*
340 * The daemon has exited; reset the state.
341 */
342 fcopy_transaction.state = HVUTIL_DEVICE_INIT;
343
344 if (cancel_delayed_work_sync(&fcopy_timeout_work))
345 fcopy_respond_to_host(HV_E_FAIL);
346}
347
348int hv_fcopy_init(struct hv_util_service *srv)
349{
350 recv_buffer = srv->recv_buffer;
351 fcopy_transaction.recv_channel = srv->channel;
352 fcopy_transaction.recv_channel->max_pkt_size = HV_HYP_PAGE_SIZE * 2;
353
354 /*
355 * When this driver loads, the user level daemon that
356 * processes the host requests may not yet be running.
357 * Defer processing channel callbacks until the daemon
358 * has registered.
359 */
360 fcopy_transaction.state = HVUTIL_DEVICE_INIT;
361
362 hvt = hvutil_transport_init(fcopy_devname, 0, 0,
363 fcopy_on_msg, fcopy_on_reset);
364 if (!hvt)
365 return -EFAULT;
366
367 return 0;
368}
369
370static void hv_fcopy_cancel_work(void)
371{
372 cancel_delayed_work_sync(&fcopy_timeout_work);
373 cancel_work_sync(&fcopy_send_work);
374}
375
376int hv_fcopy_pre_suspend(void)
377{
378 struct vmbus_channel *channel = fcopy_transaction.recv_channel;
379 struct hv_fcopy_hdr *fcopy_msg;
380
381 /*
382 * Fake a CANCEL_FCOPY message for the user space daemon in case the
383 * daemon is in the middle of copying some file. It doesn't matter if
384 * there is already a message pending to be delivered to the user
385 * space since we force fcopy_transaction.state to be HVUTIL_READY, so
386 * the user space daemon's write() will fail with EINVAL (see
387 * fcopy_on_msg()), and the daemon will reset the device by closing
388 * and re-opening it.
389 */
390 fcopy_msg = kzalloc(sizeof(*fcopy_msg), GFP_KERNEL);
391 if (!fcopy_msg)
392 return -ENOMEM;
393
394 tasklet_disable(&channel->callback_event);
395
396 fcopy_msg->operation = CANCEL_FCOPY;
397
398 hv_fcopy_cancel_work();
399
400 /* We don't care about the return value. */
401 hvutil_transport_send(hvt, fcopy_msg, sizeof(*fcopy_msg), NULL);
402
403 kfree(fcopy_msg);
404
405 fcopy_transaction.state = HVUTIL_READY;
406
407 /* tasklet_enable() will be called in hv_fcopy_pre_resume(). */
408 return 0;
409}
410
411int hv_fcopy_pre_resume(void)
412{
413 struct vmbus_channel *channel = fcopy_transaction.recv_channel;
414
415 tasklet_enable(&channel->callback_event);
416
417 return 0;
418}
419
420void hv_fcopy_deinit(void)
421{
422 fcopy_transaction.state = HVUTIL_DEVICE_DYING;
423
424 hv_fcopy_cancel_work();
425
426 hvutil_transport_destroy(hvt);
427}