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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/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 | |
35 | static const int fcopy_versions[] = { | |
36 | WIN8_SRV_VERSION | |
37 | }; | |
38 | ||
39 | #define FW_VER_COUNT 1 | |
40 | static 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 | ||
58 | static 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 | ||
66 | static void fcopy_respond_to_host(int error); | |
67 | static void fcopy_send_data(struct work_struct *dummy); | |
68 | static void fcopy_timeout_func(struct work_struct *dummy); | |
69 | static DECLARE_DELAYED_WORK(fcopy_timeout_work, fcopy_timeout_func); | |
70 | static DECLARE_WORK(fcopy_send_work, fcopy_send_data); | |
71 | static const char fcopy_devname[] = "vmbus/hv_fcopy"; | |
72 | static u8 *recv_buffer; | |
73 | static struct hvutil_transport *hvt; | |
74 | /* | |
75 | * This state maintains the version number registered by the daemon. | |
76 | */ | |
77 | static int dm_reg_value; | |
78 | ||
79 | static 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 | ||
86 | static 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 | ||
96 | static 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 | ||
102 | static 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 | ||
131 | static 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 | default: | |
174 | out_src = fcopy_transaction.fcopy_msg; | |
175 | out_len = fcopy_transaction.recv_len; | |
176 | break; | |
177 | } | |
178 | ||
179 | fcopy_transaction.state = HVUTIL_USERSPACE_REQ; | |
180 | rc = hvutil_transport_send(hvt, out_src, out_len, NULL); | |
181 | if (rc) { | |
182 | pr_debug("FCP: failed to communicate to the daemon: %d\n", rc); | |
183 | if (cancel_delayed_work_sync(&fcopy_timeout_work)) { | |
184 | fcopy_respond_to_host(HV_E_FAIL); | |
185 | fcopy_transaction.state = HVUTIL_READY; | |
186 | } | |
187 | } | |
188 | kfree(smsg_out); | |
189 | ||
190 | return; | |
191 | } | |
192 | ||
193 | /* | |
194 | * Send a response back to the host. | |
195 | */ | |
196 | ||
197 | static void | |
198 | fcopy_respond_to_host(int error) | |
199 | { | |
200 | struct icmsg_hdr *icmsghdr; | |
201 | u32 buf_len; | |
202 | struct vmbus_channel *channel; | |
203 | u64 req_id; | |
204 | ||
205 | /* | |
206 | * Copy the global state for completing the transaction. Note that | |
207 | * only one transaction can be active at a time. This is guaranteed | |
208 | * by the file copy protocol implemented by the host. Furthermore, | |
209 | * the "transaction active" state we maintain ensures that there can | |
210 | * only be one active transaction at a time. | |
211 | */ | |
212 | ||
213 | buf_len = fcopy_transaction.recv_len; | |
214 | channel = fcopy_transaction.recv_channel; | |
215 | req_id = fcopy_transaction.recv_req_id; | |
216 | ||
217 | icmsghdr = (struct icmsg_hdr *) | |
218 | &recv_buffer[sizeof(struct vmbuspipe_hdr)]; | |
219 | ||
220 | if (channel->onchannel_callback == NULL) | |
221 | /* | |
222 | * We have raced with util driver being unloaded; | |
223 | * silently return. | |
224 | */ | |
225 | return; | |
226 | ||
227 | icmsghdr->status = error; | |
228 | icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE; | |
229 | vmbus_sendpacket(channel, recv_buffer, buf_len, req_id, | |
230 | VM_PKT_DATA_INBAND, 0); | |
231 | } | |
232 | ||
233 | void hv_fcopy_onchannelcallback(void *context) | |
234 | { | |
235 | struct vmbus_channel *channel = context; | |
236 | u32 recvlen; | |
237 | u64 requestid; | |
238 | struct hv_fcopy_hdr *fcopy_msg; | |
239 | struct icmsg_hdr *icmsghdr; | |
240 | int fcopy_srv_version; | |
241 | ||
242 | if (fcopy_transaction.state > HVUTIL_READY) | |
243 | return; | |
244 | ||
245 | vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen, | |
246 | &requestid); | |
247 | if (recvlen <= 0) | |
248 | return; | |
249 | ||
250 | icmsghdr = (struct icmsg_hdr *)&recv_buffer[ | |
251 | sizeof(struct vmbuspipe_hdr)]; | |
252 | if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) { | |
253 | if (vmbus_prep_negotiate_resp(icmsghdr, recv_buffer, | |
254 | fw_versions, FW_VER_COUNT, | |
255 | fcopy_versions, FCOPY_VER_COUNT, | |
256 | NULL, &fcopy_srv_version)) { | |
257 | ||
258 | pr_info("FCopy IC version %d.%d\n", | |
259 | fcopy_srv_version >> 16, | |
260 | fcopy_srv_version & 0xFFFF); | |
261 | } | |
262 | } else { | |
263 | fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[ | |
264 | sizeof(struct vmbuspipe_hdr) + | |
265 | sizeof(struct icmsg_hdr)]; | |
266 | ||
267 | /* | |
268 | * Stash away this global state for completing the | |
269 | * transaction; note transactions are serialized. | |
270 | */ | |
271 | ||
272 | fcopy_transaction.recv_len = recvlen; | |
273 | fcopy_transaction.recv_req_id = requestid; | |
274 | fcopy_transaction.fcopy_msg = fcopy_msg; | |
275 | ||
276 | if (fcopy_transaction.state < HVUTIL_READY) { | |
277 | /* Userspace is not registered yet */ | |
278 | fcopy_respond_to_host(HV_E_FAIL); | |
279 | return; | |
280 | } | |
281 | fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED; | |
282 | ||
283 | /* | |
284 | * Send the information to the user-level daemon. | |
285 | */ | |
286 | schedule_work(&fcopy_send_work); | |
287 | schedule_delayed_work(&fcopy_timeout_work, | |
288 | HV_UTIL_TIMEOUT * HZ); | |
289 | return; | |
290 | } | |
291 | icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE; | |
292 | vmbus_sendpacket(channel, recv_buffer, recvlen, requestid, | |
293 | VM_PKT_DATA_INBAND, 0); | |
294 | } | |
295 | ||
296 | /* Callback when data is received from userspace */ | |
297 | static int fcopy_on_msg(void *msg, int len) | |
298 | { | |
299 | int *val = (int *)msg; | |
300 | ||
301 | if (len != sizeof(int)) | |
302 | return -EINVAL; | |
303 | ||
304 | if (fcopy_transaction.state == HVUTIL_DEVICE_INIT) | |
305 | return fcopy_handle_handshake(*val); | |
306 | ||
307 | if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ) | |
308 | return -EINVAL; | |
309 | ||
310 | /* | |
311 | * Complete the transaction by forwarding the result | |
312 | * to the host. But first, cancel the timeout. | |
313 | */ | |
314 | if (cancel_delayed_work_sync(&fcopy_timeout_work)) { | |
315 | fcopy_transaction.state = HVUTIL_USERSPACE_RECV; | |
316 | fcopy_respond_to_host(*val); | |
317 | hv_poll_channel(fcopy_transaction.recv_channel, | |
318 | fcopy_poll_wrapper); | |
319 | } | |
320 | ||
321 | return 0; | |
322 | } | |
323 | ||
324 | static void fcopy_on_reset(void) | |
325 | { | |
326 | /* | |
327 | * The daemon has exited; reset the state. | |
328 | */ | |
329 | fcopy_transaction.state = HVUTIL_DEVICE_INIT; | |
330 | ||
331 | if (cancel_delayed_work_sync(&fcopy_timeout_work)) | |
332 | fcopy_respond_to_host(HV_E_FAIL); | |
333 | } | |
334 | ||
335 | int hv_fcopy_init(struct hv_util_service *srv) | |
336 | { | |
337 | recv_buffer = srv->recv_buffer; | |
338 | fcopy_transaction.recv_channel = srv->channel; | |
339 | ||
340 | /* | |
341 | * When this driver loads, the user level daemon that | |
342 | * processes the host requests may not yet be running. | |
343 | * Defer processing channel callbacks until the daemon | |
344 | * has registered. | |
345 | */ | |
346 | fcopy_transaction.state = HVUTIL_DEVICE_INIT; | |
347 | ||
348 | hvt = hvutil_transport_init(fcopy_devname, 0, 0, | |
349 | fcopy_on_msg, fcopy_on_reset); | |
350 | if (!hvt) | |
351 | return -EFAULT; | |
352 | ||
353 | return 0; | |
354 | } | |
355 | ||
356 | void hv_fcopy_deinit(void) | |
357 | { | |
358 | fcopy_transaction.state = HVUTIL_DEVICE_DYING; | |
359 | cancel_delayed_work_sync(&fcopy_timeout_work); | |
360 | hvutil_transport_destroy(hvt); | |
361 | } |