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)
34 #define FCOPY_VER_COUNT 1
35 static const int fcopy_versions[] = {
39 #define FW_VER_COUNT 1
40 static const int fw_versions[] = {
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.
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
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. */
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 static struct completion release_event;
76 * This state maintains the version number registered by the daemon.
78 static int dm_reg_value;
80 static void fcopy_poll_wrapper(void *channel)
82 /* Transaction is finished, reset the state here to avoid races. */
83 fcopy_transaction.state = HVUTIL_READY;
84 hv_fcopy_onchannelcallback(channel);
87 static void fcopy_timeout_func(struct work_struct *dummy)
90 * If the timer fires, the user-mode component has not responded;
91 * process the pending transaction.
93 fcopy_respond_to_host(HV_E_FAIL);
94 hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
97 static void fcopy_register_done(void)
99 pr_debug("FCP: userspace daemon registered\n");
100 hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
103 static int fcopy_handle_handshake(u32 version)
105 u32 our_ver = FCOPY_CURRENT_VERSION;
108 case FCOPY_VERSION_0:
109 /* Daemon doesn't expect us to reply */
110 dm_reg_value = version;
112 case FCOPY_VERSION_1:
113 /* Daemon expects us to reply with our own version */
114 if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver),
115 fcopy_register_done))
117 dm_reg_value = version;
121 * For now we will fail the registration.
122 * If and when we have multiple versions to
123 * deal with, we will be backward compatible.
124 * We will add this code when needed.
128 pr_debug("FCP: userspace daemon ver. %d connected\n", version);
132 static void fcopy_send_data(struct work_struct *dummy)
134 struct hv_start_fcopy *smsg_out = NULL;
135 int operation = fcopy_transaction.fcopy_msg->operation;
136 struct hv_start_fcopy *smsg_in;
141 * The strings sent from the host are encoded in
142 * in utf16; convert it to utf8 strings.
143 * The host assures us that the utf16 strings will not exceed
144 * the max lengths specified. We will however, reserve room
145 * for the string terminating character - in the utf16s_utf8s()
146 * function we limit the size of the buffer where the converted
147 * string is placed to W_MAX_PATH -1 to guarantee
148 * that the strings can be properly terminated!
152 case START_FILE_COPY:
153 out_len = sizeof(struct hv_start_fcopy);
154 smsg_out = kzalloc(sizeof(*smsg_out), GFP_KERNEL);
158 smsg_out->hdr.operation = operation;
159 smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
161 utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
163 (__u8 *)&smsg_out->file_name, W_MAX_PATH - 1);
165 utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
167 (__u8 *)&smsg_out->path_name, W_MAX_PATH - 1);
169 smsg_out->copy_flags = smsg_in->copy_flags;
170 smsg_out->file_size = smsg_in->file_size;
175 out_src = fcopy_transaction.fcopy_msg;
176 out_len = fcopy_transaction.recv_len;
180 fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
181 rc = hvutil_transport_send(hvt, out_src, out_len, NULL);
183 pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
184 if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
185 fcopy_respond_to_host(HV_E_FAIL);
186 fcopy_transaction.state = HVUTIL_READY;
195 * Send a response back to the host.
199 fcopy_respond_to_host(int error)
201 struct icmsg_hdr *icmsghdr;
203 struct vmbus_channel *channel;
207 * Copy the global state for completing the transaction. Note that
208 * only one transaction can be active at a time. This is guaranteed
209 * by the file copy protocol implemented by the host. Furthermore,
210 * the "transaction active" state we maintain ensures that there can
211 * only be one active transaction at a time.
214 buf_len = fcopy_transaction.recv_len;
215 channel = fcopy_transaction.recv_channel;
216 req_id = fcopy_transaction.recv_req_id;
218 icmsghdr = (struct icmsg_hdr *)
219 &recv_buffer[sizeof(struct vmbuspipe_hdr)];
221 if (channel->onchannel_callback == NULL)
223 * We have raced with util driver being unloaded;
228 icmsghdr->status = error;
229 icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
230 vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
231 VM_PKT_DATA_INBAND, 0);
234 void hv_fcopy_onchannelcallback(void *context)
236 struct vmbus_channel *channel = context;
239 struct hv_fcopy_hdr *fcopy_msg;
240 struct icmsg_hdr *icmsghdr;
241 int fcopy_srv_version;
243 if (fcopy_transaction.state > HVUTIL_READY)
246 vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
251 icmsghdr = (struct icmsg_hdr *)&recv_buffer[
252 sizeof(struct vmbuspipe_hdr)];
253 if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
254 if (vmbus_prep_negotiate_resp(icmsghdr, recv_buffer,
255 fw_versions, FW_VER_COUNT,
256 fcopy_versions, FCOPY_VER_COUNT,
257 NULL, &fcopy_srv_version)) {
259 pr_info("FCopy IC version %d.%d\n",
260 fcopy_srv_version >> 16,
261 fcopy_srv_version & 0xFFFF);
264 fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
265 sizeof(struct vmbuspipe_hdr) +
266 sizeof(struct icmsg_hdr)];
269 * Stash away this global state for completing the
270 * transaction; note transactions are serialized.
273 fcopy_transaction.recv_len = recvlen;
274 fcopy_transaction.recv_req_id = requestid;
275 fcopy_transaction.fcopy_msg = fcopy_msg;
277 if (fcopy_transaction.state < HVUTIL_READY) {
278 /* Userspace is not registered yet */
279 fcopy_respond_to_host(HV_E_FAIL);
282 fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
285 * Send the information to the user-level daemon.
287 schedule_work(&fcopy_send_work);
288 schedule_delayed_work(&fcopy_timeout_work,
289 HV_UTIL_TIMEOUT * HZ);
292 icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
293 vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
294 VM_PKT_DATA_INBAND, 0);
297 /* Callback when data is received from userspace */
298 static int fcopy_on_msg(void *msg, int len)
300 int *val = (int *)msg;
302 if (len != sizeof(int))
305 if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
306 return fcopy_handle_handshake(*val);
308 if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
312 * Complete the transaction by forwarding the result
313 * to the host. But first, cancel the timeout.
315 if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
316 fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
317 fcopy_respond_to_host(*val);
318 hv_poll_channel(fcopy_transaction.recv_channel,
325 static void fcopy_on_reset(void)
328 * The daemon has exited; reset the state.
330 fcopy_transaction.state = HVUTIL_DEVICE_INIT;
332 if (cancel_delayed_work_sync(&fcopy_timeout_work))
333 fcopy_respond_to_host(HV_E_FAIL);
334 complete(&release_event);
337 int hv_fcopy_init(struct hv_util_service *srv)
339 recv_buffer = srv->recv_buffer;
340 fcopy_transaction.recv_channel = srv->channel;
342 init_completion(&release_event);
344 * When this driver loads, the user level daemon that
345 * processes the host requests may not yet be running.
346 * Defer processing channel callbacks until the daemon
349 fcopy_transaction.state = HVUTIL_DEVICE_INIT;
351 hvt = hvutil_transport_init(fcopy_devname, 0, 0,
352 fcopy_on_msg, fcopy_on_reset);
359 void hv_fcopy_deinit(void)
361 fcopy_transaction.state = HVUTIL_DEVICE_DYING;
362 cancel_delayed_work_sync(&fcopy_timeout_work);
363 hvutil_transport_destroy(hvt);
364 wait_for_completion(&release_event);