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K. Y. Srinivasan013254762014-02-16 11:34:30 -08001/*
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
K. Y. Srinivasan013254762014-02-16 11:34:30 -080022#include <linux/nls.h>
23#include <linux/workqueue.h>
K. Y. Srinivasan013254762014-02-16 11:34:30 -080024#include <linux/hyperv.h>
25#include <linux/sched.h>
K. Y. Srinivasan013254762014-02-16 11:34:30 -080026
27#include "hyperv_vmbus.h"
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -070028#include "hv_utils_transport.h"
K. Y. Srinivasan013254762014-02-16 11:34:30 -080029
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.
K. Y. Srinivasan013254762014-02-16 11:34:30 -080046 */
47
48static struct {
Vitaly Kuznetsov4c93ccc2015-04-11 18:07:49 -070049 int state; /* hvutil_device_state */
K. Y. Srinivasan013254762014-02-16 11:34:30 -080050 int recv_len; /* number of bytes received. */
51 struct hv_fcopy_hdr *fcopy_msg; /* current message */
K. Y. Srinivasan013254762014-02-16 11:34:30 -080052 struct vmbus_channel *recv_channel; /* chn we got the request */
53 u64 recv_req_id; /* request ID. */
K. Y. Srinivasan013254762014-02-16 11:34:30 -080054} fcopy_transaction;
55
K. Y. Srinivasan013254762014-02-16 11:34:30 -080056static void fcopy_respond_to_host(int error);
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -070057static void fcopy_send_data(struct work_struct *dummy);
Vitaly Kuznetsov1d072332015-04-11 18:07:45 -070058static void fcopy_timeout_func(struct work_struct *dummy);
59static DECLARE_DELAYED_WORK(fcopy_timeout_work, fcopy_timeout_func);
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -070060static DECLARE_WORK(fcopy_send_work, fcopy_send_data);
61static const char fcopy_devname[] = "vmbus/hv_fcopy";
K. Y. Srinivasan013254762014-02-16 11:34:30 -080062static u8 *recv_buffer;
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -070063static struct hvutil_transport *hvt;
K. Y. Srinivasan4db47d92016-12-22 16:54:02 -080064static struct completion release_event;
Vitaly Kuznetsova4d1ee52015-04-11 18:07:58 -070065/*
66 * This state maintains the version number registered by the daemon.
67 */
68static int dm_reg_value;
K. Y. Srinivasan013254762014-02-16 11:34:30 -080069
Olaf Hering3cace4a2015-12-14 16:01:33 -080070static void fcopy_poll_wrapper(void *channel)
71{
72 /* Transaction is finished, reset the state here to avoid races. */
73 fcopy_transaction.state = HVUTIL_READY;
74 hv_fcopy_onchannelcallback(channel);
75}
76
Vitaly Kuznetsov1d072332015-04-11 18:07:45 -070077static void fcopy_timeout_func(struct work_struct *dummy)
K. Y. Srinivasan013254762014-02-16 11:34:30 -080078{
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);
Olaf Hering3cace4a2015-12-14 16:01:33 -080084 hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
K. Y. Srinivasan013254762014-02-16 11:34:30 -080085}
86
Vitaly Kuznetsove0fa3e52016-06-09 17:08:57 -070087static 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
K. Y. Srinivasan013254762014-02-16 11:34:30 -080093static int fcopy_handle_handshake(u32 version)
94{
Vitaly Kuznetsova4d1ee52015-04-11 18:07:58 -070095 u32 our_ver = FCOPY_CURRENT_VERSION;
96
K. Y. Srinivasan013254762014-02-16 11:34:30 -080097 switch (version) {
Vitaly Kuznetsova4d1ee52015-04-11 18:07:58 -070098 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 */
Vitaly Kuznetsove0fa3e52016-06-09 17:08:57 -0700104 if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver),
105 fcopy_register_done))
Vitaly Kuznetsova4d1ee52015-04-11 18:07:58 -0700106 return -EFAULT;
107 dm_reg_value = version;
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800108 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 }
Vitaly Kuznetsove0fa3e52016-06-09 17:08:57 -0700118 pr_debug("FCP: userspace daemon ver. %d connected\n", version);
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800119 return 0;
120}
121
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700122static void fcopy_send_data(struct work_struct *dummy)
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800123{
Vitaly Kuznetsov25ef06f2015-08-01 16:08:12 -0700124 struct hv_start_fcopy *smsg_out = NULL;
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800125 int operation = fcopy_transaction.fcopy_msg->operation;
126 struct hv_start_fcopy *smsg_in;
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700127 void *out_src;
128 int rc, out_len;
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800129
130 /*
131 * The strings sent from the host are encoded in
132 * in utf16; convert it to utf8 strings.
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:
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700143 out_len = sizeof(struct hv_start_fcopy);
Vitaly Kuznetsov25ef06f2015-08-01 16:08:12 -0700144 smsg_out = kzalloc(sizeof(*smsg_out), GFP_KERNEL);
145 if (!smsg_out)
146 return;
147
148 smsg_out->hdr.operation = operation;
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800149 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,
Vitaly Kuznetsov25ef06f2015-08-01 16:08:12 -0700153 (__u8 *)&smsg_out->file_name, W_MAX_PATH - 1);
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800154
155 utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
156 UTF16_LITTLE_ENDIAN,
Vitaly Kuznetsov25ef06f2015-08-01 16:08:12 -0700157 (__u8 *)&smsg_out->path_name, W_MAX_PATH - 1);
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800158
Vitaly Kuznetsov25ef06f2015-08-01 16:08:12 -0700159 smsg_out->copy_flags = smsg_in->copy_flags;
160 smsg_out->file_size = smsg_in->file_size;
161 out_src = smsg_out;
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800162 break;
163
164 default:
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700165 out_src = fcopy_transaction.fcopy_msg;
166 out_len = fcopy_transaction.recv_len;
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800167 break;
168 }
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700169
170 fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
Vitaly Kuznetsove0fa3e52016-06-09 17:08:57 -0700171 rc = hvutil_transport_send(hvt, out_src, out_len, NULL);
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700172 if (rc) {
173 pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
174 if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
175 fcopy_respond_to_host(HV_E_FAIL);
176 fcopy_transaction.state = HVUTIL_READY;
177 }
178 }
Vitaly Kuznetsov25ef06f2015-08-01 16:08:12 -0700179 kfree(smsg_out);
180
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800181 return;
182}
183
184/*
185 * Send a response back to the host.
186 */
187
188static void
189fcopy_respond_to_host(int error)
190{
191 struct icmsg_hdr *icmsghdr;
192 u32 buf_len;
193 struct vmbus_channel *channel;
194 u64 req_id;
195
196 /*
197 * Copy the global state for completing the transaction. Note that
198 * only one transaction can be active at a time. This is guaranteed
199 * by the file copy protocol implemented by the host. Furthermore,
200 * the "transaction active" state we maintain ensures that there can
201 * only be one active transaction at a time.
202 */
203
204 buf_len = fcopy_transaction.recv_len;
205 channel = fcopy_transaction.recv_channel;
206 req_id = fcopy_transaction.recv_req_id;
207
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800208 icmsghdr = (struct icmsg_hdr *)
209 &recv_buffer[sizeof(struct vmbuspipe_hdr)];
210
211 if (channel->onchannel_callback == NULL)
212 /*
213 * We have raced with util driver being unloaded;
214 * silently return.
215 */
216 return;
217
218 icmsghdr->status = error;
219 icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
220 vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
221 VM_PKT_DATA_INBAND, 0);
222}
223
224void hv_fcopy_onchannelcallback(void *context)
225{
226 struct vmbus_channel *channel = context;
227 u32 recvlen;
228 u64 requestid;
229 struct hv_fcopy_hdr *fcopy_msg;
230 struct icmsg_hdr *icmsghdr;
231 struct icmsg_negotiate *negop = NULL;
232 int util_fw_version;
233 int fcopy_srv_version;
234
Olaf Hering3cace4a2015-12-14 16:01:33 -0800235 if (fcopy_transaction.state > HVUTIL_READY)
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800236 return;
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800237
238 vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
239 &requestid);
240 if (recvlen <= 0)
241 return;
242
243 icmsghdr = (struct icmsg_hdr *)&recv_buffer[
244 sizeof(struct vmbuspipe_hdr)];
245 if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
246 util_fw_version = UTIL_FW_VERSION;
247 fcopy_srv_version = WIN8_SRV_VERSION;
248 vmbus_prep_negotiate_resp(icmsghdr, negop, recv_buffer,
249 util_fw_version, fcopy_srv_version);
250 } else {
251 fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
252 sizeof(struct vmbuspipe_hdr) +
253 sizeof(struct icmsg_hdr)];
254
255 /*
256 * Stash away this global state for completing the
257 * transaction; note transactions are serialized.
258 */
259
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800260 fcopy_transaction.recv_len = recvlen;
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800261 fcopy_transaction.recv_req_id = requestid;
262 fcopy_transaction.fcopy_msg = fcopy_msg;
263
Vitaly Kuznetsov4c93ccc2015-04-11 18:07:49 -0700264 if (fcopy_transaction.state < HVUTIL_READY) {
265 /* Userspace is not registered yet */
266 fcopy_respond_to_host(HV_E_FAIL);
267 return;
268 }
269 fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
270
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800271 /*
272 * Send the information to the user-level daemon.
273 */
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700274 schedule_work(&fcopy_send_work);
K. Y. Srinivasanc0b200c2015-12-14 16:01:32 -0800275 schedule_delayed_work(&fcopy_timeout_work,
276 HV_UTIL_TIMEOUT * HZ);
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800277 return;
278 }
279 icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
280 vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
281 VM_PKT_DATA_INBAND, 0);
282}
283
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700284/* Callback when data is received from userspace */
285static int fcopy_on_msg(void *msg, int len)
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800286{
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700287 int *val = (int *)msg;
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800288
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700289 if (len != sizeof(int))
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800290 return -EINVAL;
291
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700292 if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
293 return fcopy_handle_handshake(*val);
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800294
Vitaly Kuznetsov4c93ccc2015-04-11 18:07:49 -0700295 if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
296 return -EINVAL;
297
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800298 /*
299 * Complete the transaction by forwarding the result
300 * to the host. But first, cancel the timeout.
301 */
Vitaly Kuznetsov4c93ccc2015-04-11 18:07:49 -0700302 if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
303 fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700304 fcopy_respond_to_host(*val);
Olaf Hering3cace4a2015-12-14 16:01:33 -0800305 hv_poll_channel(fcopy_transaction.recv_channel,
306 fcopy_poll_wrapper);
Vitaly Kuznetsov242f3122015-04-11 18:07:42 -0700307 }
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800308
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800309 return 0;
310}
311
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700312static void fcopy_on_reset(void)
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800313{
314 /*
315 * The daemon has exited; reset the state.
316 */
Vitaly Kuznetsov4c93ccc2015-04-11 18:07:49 -0700317 fcopy_transaction.state = HVUTIL_DEVICE_INIT;
Dexuan Cuid9b16522015-01-14 01:55:10 -0800318
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700319 if (cancel_delayed_work_sync(&fcopy_timeout_work))
Dexuan Cuid9b16522015-01-14 01:55:10 -0800320 fcopy_respond_to_host(HV_E_FAIL);
K. Y. Srinivasan4db47d92016-12-22 16:54:02 -0800321 complete(&release_event);
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800322}
323
324int hv_fcopy_init(struct hv_util_service *srv)
325{
326 recv_buffer = srv->recv_buffer;
K. Y. Srinivasanb9830d12016-02-26 15:13:19 -0800327 fcopy_transaction.recv_channel = srv->channel;
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800328
K. Y. Srinivasan4db47d92016-12-22 16:54:02 -0800329 init_completion(&release_event);
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800330 /*
331 * When this driver loads, the user level daemon that
332 * processes the host requests may not yet be running.
333 * Defer processing channel callbacks until the daemon
334 * has registered.
335 */
Vitaly Kuznetsov4c93ccc2015-04-11 18:07:49 -0700336 fcopy_transaction.state = HVUTIL_DEVICE_INIT;
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800337
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700338 hvt = hvutil_transport_init(fcopy_devname, 0, 0,
339 fcopy_on_msg, fcopy_on_reset);
340 if (!hvt)
341 return -EFAULT;
342
343 return 0;
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800344}
345
346void hv_fcopy_deinit(void)
347{
Vitaly Kuznetsov4c93ccc2015-04-11 18:07:49 -0700348 fcopy_transaction.state = HVUTIL_DEVICE_DYING;
Vitaly Kuznetsov1d072332015-04-11 18:07:45 -0700349 cancel_delayed_work_sync(&fcopy_timeout_work);
Vitaly Kuznetsovc7e490f2015-04-11 18:07:53 -0700350 hvutil_transport_destroy(hvt);
K. Y. Srinivasan4db47d92016-12-22 16:54:02 -0800351 wait_for_completion(&release_event);
K. Y. Srinivasan013254762014-02-16 11:34:30 -0800352}