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git.proxmox.com Git - mirror_ubuntu-hirsute-kernel.git/blob - drivers/hv/hv_fcopy.c
1 // SPDX-License-Identifier: GPL-2.0-only
3 * An implementation of file copy service.
5 * Copyright (C) 2014, Microsoft, Inc.
7 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/nls.h>
13 #include <linux/workqueue.h>
14 #include <linux/hyperv.h>
15 #include <linux/sched.h>
17 #include "hyperv_vmbus.h"
18 #include "hv_utils_transport.h"
20 #define WIN8_SRV_MAJOR 1
21 #define WIN8_SRV_MINOR 1
22 #define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
24 #define FCOPY_VER_COUNT 1
25 static const int fcopy_versions
[] = {
29 #define FW_VER_COUNT 1
30 static const int fw_versions
[] = {
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. */
56 static void fcopy_respond_to_host(int error
);
57 static void fcopy_send_data(struct work_struct
*dummy
);
58 static void fcopy_timeout_func(struct work_struct
*dummy
);
59 static DECLARE_DELAYED_WORK(fcopy_timeout_work
, fcopy_timeout_func
);
60 static DECLARE_WORK(fcopy_send_work
, fcopy_send_data
);
61 static const char fcopy_devname
[] = "vmbus/hv_fcopy";
62 static u8
*recv_buffer
;
63 static struct hvutil_transport
*hvt
;
65 * This state maintains the version number registered by the daemon.
67 static int dm_reg_value
;
69 static void fcopy_poll_wrapper(void *channel
)
71 /* Transaction is finished, reset the state here to avoid races. */
72 fcopy_transaction
.state
= HVUTIL_READY
;
73 hv_fcopy_onchannelcallback(channel
);
76 static void fcopy_timeout_func(struct work_struct
*dummy
)
79 * If the timer fires, the user-mode component has not responded;
80 * process the pending transaction.
82 fcopy_respond_to_host(HV_E_FAIL
);
83 hv_poll_channel(fcopy_transaction
.recv_channel
, fcopy_poll_wrapper
);
86 static void fcopy_register_done(void)
88 pr_debug("FCP: userspace daemon registered\n");
89 hv_poll_channel(fcopy_transaction
.recv_channel
, fcopy_poll_wrapper
);
92 static int fcopy_handle_handshake(u32 version
)
94 u32 our_ver
= FCOPY_CURRENT_VERSION
;
98 /* Daemon doesn't expect us to reply */
99 dm_reg_value
= version
;
101 case FCOPY_VERSION_1
:
102 /* Daemon expects us to reply with our own version */
103 if (hvutil_transport_send(hvt
, &our_ver
, sizeof(our_ver
),
104 fcopy_register_done
))
106 dm_reg_value
= version
;
110 * For now we will fail the registration.
111 * If and when we have multiple versions to
112 * deal with, we will be backward compatible.
113 * We will add this code when needed.
117 pr_debug("FCP: userspace daemon ver. %d connected\n", version
);
121 static void fcopy_send_data(struct work_struct
*dummy
)
123 struct hv_start_fcopy
*smsg_out
= NULL
;
124 int operation
= fcopy_transaction
.fcopy_msg
->operation
;
125 struct hv_start_fcopy
*smsg_in
;
130 * The strings sent from the host are encoded in
131 * in utf16; convert it to utf8 strings.
132 * The host assures us that the utf16 strings will not exceed
133 * the max lengths specified. We will however, reserve room
134 * for the string terminating character - in the utf16s_utf8s()
135 * function we limit the size of the buffer where the converted
136 * string is placed to W_MAX_PATH -1 to guarantee
137 * that the strings can be properly terminated!
141 case START_FILE_COPY
:
142 out_len
= sizeof(struct hv_start_fcopy
);
143 smsg_out
= kzalloc(sizeof(*smsg_out
), GFP_KERNEL
);
147 smsg_out
->hdr
.operation
= operation
;
148 smsg_in
= (struct hv_start_fcopy
*)fcopy_transaction
.fcopy_msg
;
150 utf16s_to_utf8s((wchar_t *)smsg_in
->file_name
, W_MAX_PATH
,
152 (__u8
*)&smsg_out
->file_name
, W_MAX_PATH
- 1);
154 utf16s_to_utf8s((wchar_t *)smsg_in
->path_name
, W_MAX_PATH
,
156 (__u8
*)&smsg_out
->path_name
, W_MAX_PATH
- 1);
158 smsg_out
->copy_flags
= smsg_in
->copy_flags
;
159 smsg_out
->file_size
= smsg_in
->file_size
;
164 out_src
= fcopy_transaction
.fcopy_msg
;
165 out_len
= sizeof(struct hv_do_fcopy
);
168 out_src
= fcopy_transaction
.fcopy_msg
;
169 out_len
= fcopy_transaction
.recv_len
;
173 fcopy_transaction
.state
= HVUTIL_USERSPACE_REQ
;
174 rc
= hvutil_transport_send(hvt
, out_src
, out_len
, NULL
);
176 pr_debug("FCP: failed to communicate to the daemon: %d\n", rc
);
177 if (cancel_delayed_work_sync(&fcopy_timeout_work
)) {
178 fcopy_respond_to_host(HV_E_FAIL
);
179 fcopy_transaction
.state
= HVUTIL_READY
;
186 * Send a response back to the host.
190 fcopy_respond_to_host(int error
)
192 struct icmsg_hdr
*icmsghdr
;
194 struct vmbus_channel
*channel
;
198 * Copy the global state for completing the transaction. Note that
199 * only one transaction can be active at a time. This is guaranteed
200 * by the file copy protocol implemented by the host. Furthermore,
201 * the "transaction active" state we maintain ensures that there can
202 * only be one active transaction at a time.
205 buf_len
= fcopy_transaction
.recv_len
;
206 channel
= fcopy_transaction
.recv_channel
;
207 req_id
= fcopy_transaction
.recv_req_id
;
209 icmsghdr
= (struct icmsg_hdr
*)
210 &recv_buffer
[sizeof(struct vmbuspipe_hdr
)];
212 if (channel
->onchannel_callback
== NULL
)
214 * We have raced with util driver being unloaded;
219 icmsghdr
->status
= error
;
220 icmsghdr
->icflags
= ICMSGHDRFLAG_TRANSACTION
| ICMSGHDRFLAG_RESPONSE
;
221 vmbus_sendpacket(channel
, recv_buffer
, buf_len
, req_id
,
222 VM_PKT_DATA_INBAND
, 0);
225 void hv_fcopy_onchannelcallback(void *context
)
227 struct vmbus_channel
*channel
= context
;
230 struct hv_fcopy_hdr
*fcopy_msg
;
231 struct icmsg_hdr
*icmsghdr
;
232 int fcopy_srv_version
;
234 if (fcopy_transaction
.state
> HVUTIL_READY
)
237 vmbus_recvpacket(channel
, recv_buffer
, PAGE_SIZE
* 2, &recvlen
,
242 icmsghdr
= (struct icmsg_hdr
*)&recv_buffer
[
243 sizeof(struct vmbuspipe_hdr
)];
244 if (icmsghdr
->icmsgtype
== ICMSGTYPE_NEGOTIATE
) {
245 if (vmbus_prep_negotiate_resp(icmsghdr
, recv_buffer
,
246 fw_versions
, FW_VER_COUNT
,
247 fcopy_versions
, FCOPY_VER_COUNT
,
248 NULL
, &fcopy_srv_version
)) {
250 pr_info("FCopy IC version %d.%d\n",
251 fcopy_srv_version
>> 16,
252 fcopy_srv_version
& 0xFFFF);
255 fcopy_msg
= (struct hv_fcopy_hdr
*)&recv_buffer
[
256 sizeof(struct vmbuspipe_hdr
) +
257 sizeof(struct icmsg_hdr
)];
260 * Stash away this global state for completing the
261 * transaction; note transactions are serialized.
264 fcopy_transaction
.recv_len
= recvlen
;
265 fcopy_transaction
.recv_req_id
= requestid
;
266 fcopy_transaction
.fcopy_msg
= fcopy_msg
;
268 if (fcopy_transaction
.state
< HVUTIL_READY
) {
269 /* Userspace is not registered yet */
270 fcopy_respond_to_host(HV_E_FAIL
);
273 fcopy_transaction
.state
= HVUTIL_HOSTMSG_RECEIVED
;
276 * Send the information to the user-level daemon.
278 schedule_work(&fcopy_send_work
);
279 schedule_delayed_work(&fcopy_timeout_work
,
280 HV_UTIL_TIMEOUT
* HZ
);
283 icmsghdr
->icflags
= ICMSGHDRFLAG_TRANSACTION
| ICMSGHDRFLAG_RESPONSE
;
284 vmbus_sendpacket(channel
, recv_buffer
, recvlen
, requestid
,
285 VM_PKT_DATA_INBAND
, 0);
288 /* Callback when data is received from userspace */
289 static int fcopy_on_msg(void *msg
, int len
)
291 int *val
= (int *)msg
;
293 if (len
!= sizeof(int))
296 if (fcopy_transaction
.state
== HVUTIL_DEVICE_INIT
)
297 return fcopy_handle_handshake(*val
);
299 if (fcopy_transaction
.state
!= HVUTIL_USERSPACE_REQ
)
303 * Complete the transaction by forwarding the result
304 * to the host. But first, cancel the timeout.
306 if (cancel_delayed_work_sync(&fcopy_timeout_work
)) {
307 fcopy_transaction
.state
= HVUTIL_USERSPACE_RECV
;
308 fcopy_respond_to_host(*val
);
309 hv_poll_channel(fcopy_transaction
.recv_channel
,
316 static void fcopy_on_reset(void)
319 * The daemon has exited; reset the state.
321 fcopy_transaction
.state
= HVUTIL_DEVICE_INIT
;
323 if (cancel_delayed_work_sync(&fcopy_timeout_work
))
324 fcopy_respond_to_host(HV_E_FAIL
);
327 int hv_fcopy_init(struct hv_util_service
*srv
)
329 recv_buffer
= srv
->recv_buffer
;
330 fcopy_transaction
.recv_channel
= srv
->channel
;
333 * When this driver loads, the user level daemon that
334 * processes the host requests may not yet be running.
335 * Defer processing channel callbacks until the daemon
338 fcopy_transaction
.state
= HVUTIL_DEVICE_INIT
;
340 hvt
= hvutil_transport_init(fcopy_devname
, 0, 0,
341 fcopy_on_msg
, fcopy_on_reset
);
348 void hv_fcopy_deinit(void)
350 fcopy_transaction
.state
= HVUTIL_DEVICE_DYING
;
351 cancel_delayed_work_sync(&fcopy_timeout_work
);
352 hvutil_transport_destroy(hvt
);