2 * An implementation of file copy service.
4 * Copyright (C) 2014, Microsoft, Inc.
6 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
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.
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
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22 #include <linux/nls.h>
23 #include <linux/workqueue.h>
24 #include <linux/hyperv.h>
25 #include <linux/sched.h>
27 #include "hyperv_vmbus.h"
28 #include "hv_utils_transport.h"
30 #define WIN8_SRV_MAJOR 1
31 #define WIN8_SRV_MINOR 1
32 #define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
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.
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
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 void *fcopy_context
; /* for the channel callback */
57 static void fcopy_respond_to_host(int error
);
58 static void fcopy_send_data(struct work_struct
*dummy
);
59 static void fcopy_timeout_func(struct work_struct
*dummy
);
60 static DECLARE_DELAYED_WORK(fcopy_timeout_work
, fcopy_timeout_func
);
61 static DECLARE_WORK(fcopy_send_work
, fcopy_send_data
);
62 static const char fcopy_devname
[] = "vmbus/hv_fcopy";
63 static u8
*recv_buffer
;
64 static struct hvutil_transport
*hvt
;
66 * This state maintains the version number registered by the daemon.
68 static int dm_reg_value
;
70 static void fcopy_timeout_func(struct work_struct
*dummy
)
73 * If the timer fires, the user-mode component has not responded;
74 * process the pending transaction.
76 fcopy_respond_to_host(HV_E_FAIL
);
78 /* Transaction is finished, reset the state. */
79 if (fcopy_transaction
.state
> HVUTIL_READY
)
80 fcopy_transaction
.state
= HVUTIL_READY
;
82 hv_poll_channel(fcopy_transaction
.fcopy_context
,
83 hv_fcopy_onchannelcallback
);
86 static int fcopy_handle_handshake(u32 version
)
88 u32 our_ver
= FCOPY_CURRENT_VERSION
;
92 /* Daemon doesn't expect us to reply */
93 dm_reg_value
= version
;
96 /* Daemon expects us to reply with our own version */
97 if (hvutil_transport_send(hvt
, &our_ver
, sizeof(our_ver
)))
99 dm_reg_value
= version
;
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.
110 pr_debug("FCP: userspace daemon ver. %d registered\n", version
);
111 fcopy_transaction
.state
= HVUTIL_READY
;
112 hv_poll_channel(fcopy_transaction
.fcopy_context
,
113 hv_fcopy_onchannelcallback
);
117 static void fcopy_send_data(struct work_struct
*dummy
)
119 struct hv_start_fcopy smsg_out
;
120 int operation
= fcopy_transaction
.fcopy_msg
->operation
;
121 struct hv_start_fcopy
*smsg_in
;
126 * The strings sent from the host are encoded in
127 * in utf16; convert it to utf8 strings.
128 * The host assures us that the utf16 strings will not exceed
129 * the max lengths specified. We will however, reserve room
130 * for the string terminating character - in the utf16s_utf8s()
131 * function we limit the size of the buffer where the converted
132 * string is placed to W_MAX_PATH -1 to guarantee
133 * that the strings can be properly terminated!
137 case START_FILE_COPY
:
138 out_len
= sizeof(struct hv_start_fcopy
);
139 memset(&smsg_out
, 0, out_len
);
140 smsg_out
.hdr
.operation
= operation
;
141 smsg_in
= (struct hv_start_fcopy
*)fcopy_transaction
.fcopy_msg
;
143 utf16s_to_utf8s((wchar_t *)smsg_in
->file_name
, W_MAX_PATH
,
145 (__u8
*)&smsg_out
.file_name
, W_MAX_PATH
- 1);
147 utf16s_to_utf8s((wchar_t *)smsg_in
->path_name
, W_MAX_PATH
,
149 (__u8
*)&smsg_out
.path_name
, W_MAX_PATH
- 1);
151 smsg_out
.copy_flags
= smsg_in
->copy_flags
;
152 smsg_out
.file_size
= smsg_in
->file_size
;
157 out_src
= fcopy_transaction
.fcopy_msg
;
158 out_len
= fcopy_transaction
.recv_len
;
162 fcopy_transaction
.state
= HVUTIL_USERSPACE_REQ
;
163 rc
= hvutil_transport_send(hvt
, out_src
, out_len
);
165 pr_debug("FCP: failed to communicate to the daemon: %d\n", rc
);
166 if (cancel_delayed_work_sync(&fcopy_timeout_work
)) {
167 fcopy_respond_to_host(HV_E_FAIL
);
168 fcopy_transaction
.state
= HVUTIL_READY
;
175 * Send a response back to the host.
179 fcopy_respond_to_host(int error
)
181 struct icmsg_hdr
*icmsghdr
;
183 struct vmbus_channel
*channel
;
187 * Copy the global state for completing the transaction. Note that
188 * only one transaction can be active at a time. This is guaranteed
189 * by the file copy protocol implemented by the host. Furthermore,
190 * the "transaction active" state we maintain ensures that there can
191 * only be one active transaction at a time.
194 buf_len
= fcopy_transaction
.recv_len
;
195 channel
= fcopy_transaction
.recv_channel
;
196 req_id
= fcopy_transaction
.recv_req_id
;
198 icmsghdr
= (struct icmsg_hdr
*)
199 &recv_buffer
[sizeof(struct vmbuspipe_hdr
)];
201 if (channel
->onchannel_callback
== NULL
)
203 * We have raced with util driver being unloaded;
208 icmsghdr
->status
= error
;
209 icmsghdr
->icflags
= ICMSGHDRFLAG_TRANSACTION
| ICMSGHDRFLAG_RESPONSE
;
210 vmbus_sendpacket(channel
, recv_buffer
, buf_len
, req_id
,
211 VM_PKT_DATA_INBAND
, 0);
214 void hv_fcopy_onchannelcallback(void *context
)
216 struct vmbus_channel
*channel
= context
;
219 struct hv_fcopy_hdr
*fcopy_msg
;
220 struct icmsg_hdr
*icmsghdr
;
221 struct icmsg_negotiate
*negop
= NULL
;
223 int fcopy_srv_version
;
225 if (fcopy_transaction
.state
> HVUTIL_READY
) {
227 * We will defer processing this callback once
228 * the current transaction is complete.
230 fcopy_transaction
.fcopy_context
= context
;
233 fcopy_transaction
.fcopy_context
= NULL
;
235 vmbus_recvpacket(channel
, recv_buffer
, PAGE_SIZE
* 2, &recvlen
,
240 icmsghdr
= (struct icmsg_hdr
*)&recv_buffer
[
241 sizeof(struct vmbuspipe_hdr
)];
242 if (icmsghdr
->icmsgtype
== ICMSGTYPE_NEGOTIATE
) {
243 util_fw_version
= UTIL_FW_VERSION
;
244 fcopy_srv_version
= WIN8_SRV_VERSION
;
245 vmbus_prep_negotiate_resp(icmsghdr
, negop
, recv_buffer
,
246 util_fw_version
, fcopy_srv_version
);
248 fcopy_msg
= (struct hv_fcopy_hdr
*)&recv_buffer
[
249 sizeof(struct vmbuspipe_hdr
) +
250 sizeof(struct icmsg_hdr
)];
253 * Stash away this global state for completing the
254 * transaction; note transactions are serialized.
257 fcopy_transaction
.recv_len
= recvlen
;
258 fcopy_transaction
.recv_channel
= channel
;
259 fcopy_transaction
.recv_req_id
= requestid
;
260 fcopy_transaction
.fcopy_msg
= fcopy_msg
;
262 if (fcopy_transaction
.state
< HVUTIL_READY
) {
263 /* Userspace is not registered yet */
264 fcopy_respond_to_host(HV_E_FAIL
);
267 fcopy_transaction
.state
= HVUTIL_HOSTMSG_RECEIVED
;
270 * Send the information to the user-level daemon.
272 schedule_work(&fcopy_send_work
);
273 schedule_delayed_work(&fcopy_timeout_work
, 5*HZ
);
276 icmsghdr
->icflags
= ICMSGHDRFLAG_TRANSACTION
| ICMSGHDRFLAG_RESPONSE
;
277 vmbus_sendpacket(channel
, recv_buffer
, recvlen
, requestid
,
278 VM_PKT_DATA_INBAND
, 0);
281 /* Callback when data is received from userspace */
282 static int fcopy_on_msg(void *msg
, int len
)
284 int *val
= (int *)msg
;
286 if (len
!= sizeof(int))
289 if (fcopy_transaction
.state
== HVUTIL_DEVICE_INIT
)
290 return fcopy_handle_handshake(*val
);
292 if (fcopy_transaction
.state
!= HVUTIL_USERSPACE_REQ
)
296 * Complete the transaction by forwarding the result
297 * to the host. But first, cancel the timeout.
299 if (cancel_delayed_work_sync(&fcopy_timeout_work
)) {
300 fcopy_transaction
.state
= HVUTIL_USERSPACE_RECV
;
301 fcopy_respond_to_host(*val
);
302 fcopy_transaction
.state
= HVUTIL_READY
;
303 hv_poll_channel(fcopy_transaction
.fcopy_context
,
304 hv_fcopy_onchannelcallback
);
310 static void fcopy_on_reset(void)
313 * The daemon has exited; reset the state.
315 fcopy_transaction
.state
= HVUTIL_DEVICE_INIT
;
317 if (cancel_delayed_work_sync(&fcopy_timeout_work
))
318 fcopy_respond_to_host(HV_E_FAIL
);
321 int hv_fcopy_init(struct hv_util_service
*srv
)
323 recv_buffer
= srv
->recv_buffer
;
326 * When this driver loads, the user level daemon that
327 * processes the host requests may not yet be running.
328 * Defer processing channel callbacks until the daemon
331 fcopy_transaction
.state
= HVUTIL_DEVICE_INIT
;
333 hvt
= hvutil_transport_init(fcopy_devname
, 0, 0,
334 fcopy_on_msg
, fcopy_on_reset
);
341 void hv_fcopy_deinit(void)
343 fcopy_transaction
.state
= HVUTIL_DEVICE_DYING
;
344 cancel_delayed_work_sync(&fcopy_timeout_work
);
345 hvutil_transport_destroy(hvt
);