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01325476 S |
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 | ||
01325476 S |
22 | #include <linux/nls.h> |
23 | #include <linux/workqueue.h> | |
01325476 S |
24 | #include <linux/hyperv.h> |
25 | #include <linux/sched.h> | |
01325476 S |
26 | |
27 | #include "hyperv_vmbus.h" | |
c7e490fc | 28 | #include "hv_utils_transport.h" |
01325476 S |
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 | /* | |
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. | |
01325476 S |
46 | */ |
47 | ||
48 | static struct { | |
4c93cccc | 49 | int state; /* hvutil_device_state */ |
01325476 S |
50 | int recv_len; /* number of bytes received. */ |
51 | struct hv_fcopy_hdr *fcopy_msg; /* current message */ | |
01325476 S |
52 | struct vmbus_channel *recv_channel; /* chn we got the request */ |
53 | u64 recv_req_id; /* request ID. */ | |
54 | void *fcopy_context; /* for the channel callback */ | |
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 | |
1d072339 | 70 | static void fcopy_timeout_func(struct work_struct *dummy) |
01325476 S |
71 | { |
72 | /* | |
73 | * If the timer fires, the user-mode component has not responded; | |
74 | * process the pending transaction. | |
75 | */ | |
76 | fcopy_respond_to_host(HV_E_FAIL); | |
d9b16529 | 77 | |
4c93cccc VK |
78 | /* Transaction is finished, reset the state. */ |
79 | if (fcopy_transaction.state > HVUTIL_READY) | |
80 | fcopy_transaction.state = HVUTIL_READY; | |
81 | ||
242f3122 VK |
82 | hv_poll_channel(fcopy_transaction.fcopy_context, |
83 | hv_fcopy_onchannelcallback); | |
01325476 S |
84 | } |
85 | ||
86 | static int fcopy_handle_handshake(u32 version) | |
87 | { | |
a4d1ee5b VK |
88 | u32 our_ver = FCOPY_CURRENT_VERSION; |
89 | ||
01325476 | 90 | switch (version) { |
a4d1ee5b VK |
91 | case FCOPY_VERSION_0: |
92 | /* Daemon doesn't expect us to reply */ | |
93 | dm_reg_value = version; | |
94 | break; | |
95 | case FCOPY_VERSION_1: | |
96 | /* Daemon expects us to reply with our own version */ | |
97 | if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver))) | |
98 | return -EFAULT; | |
99 | dm_reg_value = version; | |
01325476 S |
100 | break; |
101 | default: | |
102 | /* | |
103 | * For now we will fail the registration. | |
104 | * If and when we have multiple versions to | |
105 | * deal with, we will be backward compatible. | |
106 | * We will add this code when needed. | |
107 | */ | |
108 | return -EINVAL; | |
109 | } | |
110 | pr_info("FCP: user-mode registering done. Daemon version: %d\n", | |
111 | version); | |
4c93cccc | 112 | fcopy_transaction.state = HVUTIL_READY; |
242f3122 VK |
113 | hv_poll_channel(fcopy_transaction.fcopy_context, |
114 | hv_fcopy_onchannelcallback); | |
01325476 S |
115 | return 0; |
116 | } | |
117 | ||
c7e490fc | 118 | static void fcopy_send_data(struct work_struct *dummy) |
01325476 | 119 | { |
c7e490fc | 120 | struct hv_start_fcopy smsg_out; |
01325476 S |
121 | int operation = fcopy_transaction.fcopy_msg->operation; |
122 | struct hv_start_fcopy *smsg_in; | |
c7e490fc VK |
123 | void *out_src; |
124 | int rc, out_len; | |
01325476 S |
125 | |
126 | /* | |
127 | * The strings sent from the host are encoded in | |
128 | * in utf16; convert it to utf8 strings. | |
129 | * The host assures us that the utf16 strings will not exceed | |
130 | * the max lengths specified. We will however, reserve room | |
131 | * for the string terminating character - in the utf16s_utf8s() | |
132 | * function we limit the size of the buffer where the converted | |
133 | * string is placed to W_MAX_PATH -1 to guarantee | |
134 | * that the strings can be properly terminated! | |
135 | */ | |
136 | ||
137 | switch (operation) { | |
138 | case START_FILE_COPY: | |
c7e490fc VK |
139 | out_len = sizeof(struct hv_start_fcopy); |
140 | memset(&smsg_out, 0, out_len); | |
141 | smsg_out.hdr.operation = operation; | |
01325476 S |
142 | smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg; |
143 | ||
144 | utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH, | |
145 | UTF16_LITTLE_ENDIAN, | |
c7e490fc | 146 | (__u8 *)&smsg_out.file_name, W_MAX_PATH - 1); |
01325476 S |
147 | |
148 | utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH, | |
149 | UTF16_LITTLE_ENDIAN, | |
c7e490fc | 150 | (__u8 *)&smsg_out.path_name, W_MAX_PATH - 1); |
01325476 | 151 | |
c7e490fc VK |
152 | smsg_out.copy_flags = smsg_in->copy_flags; |
153 | smsg_out.file_size = smsg_in->file_size; | |
154 | out_src = &smsg_out; | |
01325476 S |
155 | break; |
156 | ||
157 | default: | |
c7e490fc VK |
158 | out_src = fcopy_transaction.fcopy_msg; |
159 | out_len = fcopy_transaction.recv_len; | |
01325476 S |
160 | break; |
161 | } | |
c7e490fc VK |
162 | |
163 | fcopy_transaction.state = HVUTIL_USERSPACE_REQ; | |
164 | rc = hvutil_transport_send(hvt, out_src, out_len); | |
165 | if (rc) { | |
166 | pr_debug("FCP: failed to communicate to the daemon: %d\n", rc); | |
167 | if (cancel_delayed_work_sync(&fcopy_timeout_work)) { | |
168 | fcopy_respond_to_host(HV_E_FAIL); | |
169 | fcopy_transaction.state = HVUTIL_READY; | |
170 | } | |
171 | } | |
01325476 S |
172 | return; |
173 | } | |
174 | ||
175 | /* | |
176 | * Send a response back to the host. | |
177 | */ | |
178 | ||
179 | static void | |
180 | fcopy_respond_to_host(int error) | |
181 | { | |
182 | struct icmsg_hdr *icmsghdr; | |
183 | u32 buf_len; | |
184 | struct vmbus_channel *channel; | |
185 | u64 req_id; | |
186 | ||
187 | /* | |
188 | * Copy the global state for completing the transaction. Note that | |
189 | * only one transaction can be active at a time. This is guaranteed | |
190 | * by the file copy protocol implemented by the host. Furthermore, | |
191 | * the "transaction active" state we maintain ensures that there can | |
192 | * only be one active transaction at a time. | |
193 | */ | |
194 | ||
195 | buf_len = fcopy_transaction.recv_len; | |
196 | channel = fcopy_transaction.recv_channel; | |
197 | req_id = fcopy_transaction.recv_req_id; | |
198 | ||
01325476 S |
199 | icmsghdr = (struct icmsg_hdr *) |
200 | &recv_buffer[sizeof(struct vmbuspipe_hdr)]; | |
201 | ||
202 | if (channel->onchannel_callback == NULL) | |
203 | /* | |
204 | * We have raced with util driver being unloaded; | |
205 | * silently return. | |
206 | */ | |
207 | return; | |
208 | ||
209 | icmsghdr->status = error; | |
210 | icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE; | |
211 | vmbus_sendpacket(channel, recv_buffer, buf_len, req_id, | |
212 | VM_PKT_DATA_INBAND, 0); | |
213 | } | |
214 | ||
215 | void hv_fcopy_onchannelcallback(void *context) | |
216 | { | |
217 | struct vmbus_channel *channel = context; | |
218 | u32 recvlen; | |
219 | u64 requestid; | |
220 | struct hv_fcopy_hdr *fcopy_msg; | |
221 | struct icmsg_hdr *icmsghdr; | |
222 | struct icmsg_negotiate *negop = NULL; | |
223 | int util_fw_version; | |
224 | int fcopy_srv_version; | |
225 | ||
4c93cccc | 226 | if (fcopy_transaction.state > HVUTIL_READY) { |
01325476 S |
227 | /* |
228 | * We will defer processing this callback once | |
229 | * the current transaction is complete. | |
230 | */ | |
231 | fcopy_transaction.fcopy_context = context; | |
232 | return; | |
233 | } | |
242f3122 | 234 | fcopy_transaction.fcopy_context = NULL; |
01325476 S |
235 | |
236 | vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen, | |
237 | &requestid); | |
238 | if (recvlen <= 0) | |
239 | return; | |
240 | ||
241 | icmsghdr = (struct icmsg_hdr *)&recv_buffer[ | |
242 | sizeof(struct vmbuspipe_hdr)]; | |
243 | if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) { | |
244 | util_fw_version = UTIL_FW_VERSION; | |
245 | fcopy_srv_version = WIN8_SRV_VERSION; | |
246 | vmbus_prep_negotiate_resp(icmsghdr, negop, recv_buffer, | |
247 | util_fw_version, fcopy_srv_version); | |
248 | } else { | |
249 | fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[ | |
250 | sizeof(struct vmbuspipe_hdr) + | |
251 | sizeof(struct icmsg_hdr)]; | |
252 | ||
253 | /* | |
254 | * Stash away this global state for completing the | |
255 | * transaction; note transactions are serialized. | |
256 | */ | |
257 | ||
01325476 S |
258 | fcopy_transaction.recv_len = recvlen; |
259 | fcopy_transaction.recv_channel = channel; | |
260 | fcopy_transaction.recv_req_id = requestid; | |
261 | fcopy_transaction.fcopy_msg = fcopy_msg; | |
262 | ||
4c93cccc VK |
263 | if (fcopy_transaction.state < HVUTIL_READY) { |
264 | /* Userspace is not registered yet */ | |
265 | fcopy_respond_to_host(HV_E_FAIL); | |
266 | return; | |
267 | } | |
268 | fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED; | |
269 | ||
01325476 S |
270 | /* |
271 | * Send the information to the user-level daemon. | |
272 | */ | |
c7e490fc | 273 | schedule_work(&fcopy_send_work); |
1d072339 | 274 | schedule_delayed_work(&fcopy_timeout_work, 5*HZ); |
01325476 S |
275 | return; |
276 | } | |
277 | icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE; | |
278 | vmbus_sendpacket(channel, recv_buffer, recvlen, requestid, | |
279 | VM_PKT_DATA_INBAND, 0); | |
280 | } | |
281 | ||
c7e490fc VK |
282 | /* Callback when data is received from userspace */ |
283 | static int fcopy_on_msg(void *msg, int len) | |
01325476 | 284 | { |
c7e490fc | 285 | int *val = (int *)msg; |
01325476 | 286 | |
c7e490fc | 287 | if (len != sizeof(int)) |
01325476 S |
288 | return -EINVAL; |
289 | ||
c7e490fc VK |
290 | if (fcopy_transaction.state == HVUTIL_DEVICE_INIT) |
291 | return fcopy_handle_handshake(*val); | |
01325476 | 292 | |
4c93cccc VK |
293 | if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ) |
294 | return -EINVAL; | |
295 | ||
01325476 S |
296 | /* |
297 | * Complete the transaction by forwarding the result | |
298 | * to the host. But first, cancel the timeout. | |
299 | */ | |
4c93cccc VK |
300 | if (cancel_delayed_work_sync(&fcopy_timeout_work)) { |
301 | fcopy_transaction.state = HVUTIL_USERSPACE_RECV; | |
c7e490fc | 302 | fcopy_respond_to_host(*val); |
4c93cccc | 303 | fcopy_transaction.state = HVUTIL_READY; |
242f3122 VK |
304 | hv_poll_channel(fcopy_transaction.fcopy_context, |
305 | hv_fcopy_onchannelcallback); | |
306 | } | |
01325476 | 307 | |
01325476 S |
308 | return 0; |
309 | } | |
310 | ||
c7e490fc | 311 | static void fcopy_on_reset(void) |
01325476 S |
312 | { |
313 | /* | |
314 | * The daemon has exited; reset the state. | |
315 | */ | |
4c93cccc | 316 | fcopy_transaction.state = HVUTIL_DEVICE_INIT; |
d9b16529 | 317 | |
c7e490fc | 318 | if (cancel_delayed_work_sync(&fcopy_timeout_work)) |
d9b16529 | 319 | fcopy_respond_to_host(HV_E_FAIL); |
01325476 S |
320 | } |
321 | ||
322 | int hv_fcopy_init(struct hv_util_service *srv) | |
323 | { | |
324 | recv_buffer = srv->recv_buffer; | |
325 | ||
326 | /* | |
327 | * When this driver loads, the user level daemon that | |
328 | * processes the host requests may not yet be running. | |
329 | * Defer processing channel callbacks until the daemon | |
330 | * has registered. | |
331 | */ | |
4c93cccc | 332 | fcopy_transaction.state = HVUTIL_DEVICE_INIT; |
01325476 | 333 | |
c7e490fc VK |
334 | hvt = hvutil_transport_init(fcopy_devname, 0, 0, |
335 | fcopy_on_msg, fcopy_on_reset); | |
336 | if (!hvt) | |
337 | return -EFAULT; | |
338 | ||
339 | return 0; | |
01325476 S |
340 | } |
341 | ||
342 | void hv_fcopy_deinit(void) | |
343 | { | |
4c93cccc | 344 | fcopy_transaction.state = HVUTIL_DEVICE_DYING; |
1d072339 | 345 | cancel_delayed_work_sync(&fcopy_timeout_work); |
c7e490fc | 346 | hvutil_transport_destroy(hvt); |
01325476 | 347 | } |