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43aa3132 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
01325476 S |
2 | /* |
3 | * An implementation of file copy service. | |
4 | * | |
5 | * Copyright (C) 2014, Microsoft, Inc. | |
6 | * | |
7 | * Author : K. Y. Srinivasan <ksrinivasan@novell.com> | |
01325476 S |
8 | */ |
9 | ||
10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
11 | ||
01325476 S |
12 | #include <linux/nls.h> |
13 | #include <linux/workqueue.h> | |
01325476 S |
14 | #include <linux/hyperv.h> |
15 | #include <linux/sched.h> | |
b14d749a | 16 | #include <asm/hyperv-tlfs.h> |
01325476 S |
17 | |
18 | #include "hyperv_vmbus.h" | |
c7e490fc | 19 | #include "hv_utils_transport.h" |
01325476 S |
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 | ||
a1656454 AN |
25 | #define FCOPY_VER_COUNT 1 |
26 | static const int fcopy_versions[] = { | |
27 | WIN8_SRV_VERSION | |
28 | }; | |
29 | ||
30 | #define FW_VER_COUNT 1 | |
31 | static const int fw_versions[] = { | |
32 | UTIL_FW_VERSION | |
33 | }; | |
34 | ||
01325476 S |
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. | |
01325476 S |
47 | */ |
48 | ||
49 | static struct { | |
4c93cccc | 50 | int state; /* hvutil_device_state */ |
01325476 S |
51 | int recv_len; /* number of bytes received. */ |
52 | struct hv_fcopy_hdr *fcopy_msg; /* current message */ | |
01325476 S |
53 | struct vmbus_channel *recv_channel; /* chn we got the request */ |
54 | u64 recv_req_id; /* request ID. */ | |
01325476 S |
55 | } fcopy_transaction; |
56 | ||
01325476 | 57 | static void fcopy_respond_to_host(int error); |
c7e490fc | 58 | static void fcopy_send_data(struct work_struct *dummy); |
1d072339 VK |
59 | static void fcopy_timeout_func(struct work_struct *dummy); |
60 | static DECLARE_DELAYED_WORK(fcopy_timeout_work, fcopy_timeout_func); | |
c7e490fc VK |
61 | static DECLARE_WORK(fcopy_send_work, fcopy_send_data); |
62 | static const char fcopy_devname[] = "vmbus/hv_fcopy"; | |
01325476 | 63 | static u8 *recv_buffer; |
c7e490fc | 64 | static struct hvutil_transport *hvt; |
a4d1ee5b VK |
65 | /* |
66 | * This state maintains the version number registered by the daemon. | |
67 | */ | |
68 | static int dm_reg_value; | |
01325476 | 69 | |
3cace4a6 OH |
70 | static void fcopy_poll_wrapper(void *channel) |
71 | { | |
72 | /* Transaction is finished, reset the state here to avoid races. */ | |
73 | fcopy_transaction.state = HVUTIL_READY; | |
238d2ed8 | 74 | tasklet_schedule(&((struct vmbus_channel *)channel)->callback_event); |
3cace4a6 OH |
75 | } |
76 | ||
1d072339 | 77 | static void fcopy_timeout_func(struct work_struct *dummy) |
01325476 S |
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); | |
3cace4a6 | 84 | hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper); |
01325476 S |
85 | } |
86 | ||
e0fa3e5e VK |
87 | static 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 | ||
01325476 S |
93 | static int fcopy_handle_handshake(u32 version) |
94 | { | |
a4d1ee5b VK |
95 | u32 our_ver = FCOPY_CURRENT_VERSION; |
96 | ||
01325476 | 97 | switch (version) { |
a4d1ee5b VK |
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 */ | |
e0fa3e5e VK |
104 | if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver), |
105 | fcopy_register_done)) | |
a4d1ee5b VK |
106 | return -EFAULT; |
107 | dm_reg_value = version; | |
01325476 S |
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 | } | |
e0fa3e5e | 118 | pr_debug("FCP: userspace daemon ver. %d connected\n", version); |
01325476 S |
119 | return 0; |
120 | } | |
121 | ||
c7e490fc | 122 | static void fcopy_send_data(struct work_struct *dummy) |
01325476 | 123 | { |
25ef06fe | 124 | struct hv_start_fcopy *smsg_out = NULL; |
01325476 S |
125 | int operation = fcopy_transaction.fcopy_msg->operation; |
126 | struct hv_start_fcopy *smsg_in; | |
c7e490fc VK |
127 | void *out_src; |
128 | int rc, out_len; | |
01325476 S |
129 | |
130 | /* | |
131 | * The strings sent from the host are encoded in | |
676576d1 | 132 | * utf16; convert it to utf8 strings. |
01325476 S |
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: | |
c7e490fc | 143 | out_len = sizeof(struct hv_start_fcopy); |
25ef06fe VK |
144 | smsg_out = kzalloc(sizeof(*smsg_out), GFP_KERNEL); |
145 | if (!smsg_out) | |
146 | return; | |
147 | ||
148 | smsg_out->hdr.operation = operation; | |
01325476 S |
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, | |
25ef06fe | 153 | (__u8 *)&smsg_out->file_name, W_MAX_PATH - 1); |
01325476 S |
154 | |
155 | utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH, | |
156 | UTF16_LITTLE_ENDIAN, | |
25ef06fe | 157 | (__u8 *)&smsg_out->path_name, W_MAX_PATH - 1); |
01325476 | 158 | |
25ef06fe VK |
159 | smsg_out->copy_flags = smsg_in->copy_flags; |
160 | smsg_out->file_size = smsg_in->file_size; | |
161 | out_src = smsg_out; | |
01325476 S |
162 | break; |
163 | ||
549e658a OH |
164 | case WRITE_TO_FILE: |
165 | out_src = fcopy_transaction.fcopy_msg; | |
166 | out_len = sizeof(struct hv_do_fcopy); | |
167 | break; | |
01325476 | 168 | default: |
c7e490fc VK |
169 | out_src = fcopy_transaction.fcopy_msg; |
170 | out_len = fcopy_transaction.recv_len; | |
01325476 S |
171 | break; |
172 | } | |
c7e490fc VK |
173 | |
174 | fcopy_transaction.state = HVUTIL_USERSPACE_REQ; | |
e0fa3e5e | 175 | rc = hvutil_transport_send(hvt, out_src, out_len, NULL); |
c7e490fc VK |
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 | } | |
25ef06fe | 183 | kfree(smsg_out); |
01325476 S |
184 | } |
185 | ||
186 | /* | |
187 | * Send a response back to the host. | |
188 | */ | |
189 | ||
190 | static void | |
191 | fcopy_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 | ||
01325476 S |
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 | ||
226 | void 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; | |
01325476 S |
233 | int fcopy_srv_version; |
234 | ||
3cace4a6 | 235 | if (fcopy_transaction.state > HVUTIL_READY) |
01325476 | 236 | return; |
01325476 | 237 | |
06caa778 AB |
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"); | |
01325476 | 240 | return; |
06caa778 AB |
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 | } | |
01325476 S |
252 | |
253 | icmsghdr = (struct icmsg_hdr *)&recv_buffer[ | |
254 | sizeof(struct vmbuspipe_hdr)]; | |
06caa778 | 255 | |
01325476 | 256 | if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) { |
06caa778 AB |
257 | if (vmbus_prep_negotiate_resp(icmsghdr, |
258 | recv_buffer, recvlen, | |
a1656454 AN |
259 | fw_versions, FW_VER_COUNT, |
260 | fcopy_versions, FCOPY_VER_COUNT, | |
1274a690 AN |
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 | } | |
06caa778 AB |
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]; | |
01325476 S |
275 | |
276 | /* | |
277 | * Stash away this global state for completing the | |
278 | * transaction; note transactions are serialized. | |
279 | */ | |
280 | ||
01325476 | 281 | fcopy_transaction.recv_len = recvlen; |
01325476 S |
282 | fcopy_transaction.recv_req_id = requestid; |
283 | fcopy_transaction.fcopy_msg = fcopy_msg; | |
284 | ||
4c93cccc VK |
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 | ||
01325476 S |
292 | /* |
293 | * Send the information to the user-level daemon. | |
294 | */ | |
c7e490fc | 295 | schedule_work(&fcopy_send_work); |
c0b200cf S |
296 | schedule_delayed_work(&fcopy_timeout_work, |
297 | HV_UTIL_TIMEOUT * HZ); | |
01325476 | 298 | return; |
06caa778 AB |
299 | } else { |
300 | pr_err_ratelimited("Fcopy request received. Invalid msg type: %d\n", | |
301 | icmsghdr->icmsgtype); | |
302 | return; | |
01325476 S |
303 | } |
304 | icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE; | |
305 | vmbus_sendpacket(channel, recv_buffer, recvlen, requestid, | |
306 | VM_PKT_DATA_INBAND, 0); | |
307 | } | |
308 | ||
c7e490fc VK |
309 | /* Callback when data is received from userspace */ |
310 | static int fcopy_on_msg(void *msg, int len) | |
01325476 | 311 | { |
c7e490fc | 312 | int *val = (int *)msg; |
01325476 | 313 | |
c7e490fc | 314 | if (len != sizeof(int)) |
01325476 S |
315 | return -EINVAL; |
316 | ||
c7e490fc VK |
317 | if (fcopy_transaction.state == HVUTIL_DEVICE_INIT) |
318 | return fcopy_handle_handshake(*val); | |
01325476 | 319 | |
4c93cccc VK |
320 | if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ) |
321 | return -EINVAL; | |
322 | ||
01325476 S |
323 | /* |
324 | * Complete the transaction by forwarding the result | |
325 | * to the host. But first, cancel the timeout. | |
326 | */ | |
4c93cccc VK |
327 | if (cancel_delayed_work_sync(&fcopy_timeout_work)) { |
328 | fcopy_transaction.state = HVUTIL_USERSPACE_RECV; | |
c7e490fc | 329 | fcopy_respond_to_host(*val); |
3cace4a6 OH |
330 | hv_poll_channel(fcopy_transaction.recv_channel, |
331 | fcopy_poll_wrapper); | |
242f3122 | 332 | } |
01325476 | 333 | |
01325476 S |
334 | return 0; |
335 | } | |
336 | ||
c7e490fc | 337 | static void fcopy_on_reset(void) |
01325476 S |
338 | { |
339 | /* | |
340 | * The daemon has exited; reset the state. | |
341 | */ | |
4c93cccc | 342 | fcopy_transaction.state = HVUTIL_DEVICE_INIT; |
d9b16529 | 343 | |
c7e490fc | 344 | if (cancel_delayed_work_sync(&fcopy_timeout_work)) |
d9b16529 | 345 | fcopy_respond_to_host(HV_E_FAIL); |
01325476 S |
346 | } |
347 | ||
348 | int hv_fcopy_init(struct hv_util_service *srv) | |
349 | { | |
350 | recv_buffer = srv->recv_buffer; | |
b9830d12 | 351 | fcopy_transaction.recv_channel = srv->channel; |
adae1e93 | 352 | fcopy_transaction.recv_channel->max_pkt_size = HV_HYP_PAGE_SIZE * 2; |
01325476 S |
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 | */ | |
4c93cccc | 360 | fcopy_transaction.state = HVUTIL_DEVICE_INIT; |
01325476 | 361 | |
c7e490fc VK |
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; | |
01325476 S |
368 | } |
369 | ||
54e19d34 DC |
370 | static void hv_fcopy_cancel_work(void) |
371 | { | |
372 | cancel_delayed_work_sync(&fcopy_timeout_work); | |
373 | cancel_work_sync(&fcopy_send_work); | |
374 | } | |
375 | ||
376 | int 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 | ||
411 | int 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 | ||
01325476 S |
420 | void hv_fcopy_deinit(void) |
421 | { | |
4c93cccc | 422 | fcopy_transaction.state = HVUTIL_DEVICE_DYING; |
54e19d34 DC |
423 | |
424 | hv_fcopy_cancel_work(); | |
425 | ||
c7e490fc | 426 | hvutil_transport_destroy(hvt); |
01325476 | 427 | } |