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. */
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;
64 static struct completion release_event;
66 * This state maintains the version number registered by the daemon.
68 static int dm_reg_value;
70 static void fcopy_poll_wrapper(void *channel)
72 /* Transaction is finished, reset the state here to avoid races. */
73 fcopy_transaction.state = HVUTIL_READY;
74 hv_fcopy_onchannelcallback(channel);
77 static void fcopy_timeout_func(struct work_struct *dummy)
80 * If the timer fires, the user-mode component has not responded;
81 * process the pending transaction.
83 fcopy_respond_to_host(HV_E_FAIL);
84 hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
87 static int fcopy_handle_handshake(u32 version)
89 u32 our_ver = FCOPY_CURRENT_VERSION;
93 /* Daemon doesn't expect us to reply */
94 dm_reg_value = version;
97 /* Daemon expects us to reply with our own version */
98 if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver)))
100 dm_reg_value = version;
104 * For now we will fail the registration.
105 * If and when we have multiple versions to
106 * deal with, we will be backward compatible.
107 * We will add this code when needed.
111 pr_debug("FCP: userspace daemon ver. %d registered\n", version);
112 hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
116 static void fcopy_send_data(struct work_struct *dummy)
118 struct hv_start_fcopy *smsg_out = NULL;
119 int operation = fcopy_transaction.fcopy_msg->operation;
120 struct hv_start_fcopy *smsg_in;
125 * The strings sent from the host are encoded in
126 * in utf16; convert it to utf8 strings.
127 * The host assures us that the utf16 strings will not exceed
128 * the max lengths specified. We will however, reserve room
129 * for the string terminating character - in the utf16s_utf8s()
130 * function we limit the size of the buffer where the converted
131 * string is placed to W_MAX_PATH -1 to guarantee
132 * that the strings can be properly terminated!
136 case START_FILE_COPY:
137 out_len = sizeof(struct hv_start_fcopy);
138 smsg_out = kzalloc(sizeof(*smsg_out), GFP_KERNEL);
142 smsg_out->hdr.operation = operation;
143 smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
145 utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
147 (__u8 *)&smsg_out->file_name, W_MAX_PATH - 1);
149 utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
151 (__u8 *)&smsg_out->path_name, W_MAX_PATH - 1);
153 smsg_out->copy_flags = smsg_in->copy_flags;
154 smsg_out->file_size = smsg_in->file_size;
159 out_src = fcopy_transaction.fcopy_msg;
160 out_len = fcopy_transaction.recv_len;
164 fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
165 rc = hvutil_transport_send(hvt, out_src, out_len);
167 pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
168 if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
169 fcopy_respond_to_host(HV_E_FAIL);
170 fcopy_transaction.state = HVUTIL_READY;
179 * Send a response back to the host.
183 fcopy_respond_to_host(int error)
185 struct icmsg_hdr *icmsghdr;
187 struct vmbus_channel *channel;
191 * Copy the global state for completing the transaction. Note that
192 * only one transaction can be active at a time. This is guaranteed
193 * by the file copy protocol implemented by the host. Furthermore,
194 * the "transaction active" state we maintain ensures that there can
195 * only be one active transaction at a time.
198 buf_len = fcopy_transaction.recv_len;
199 channel = fcopy_transaction.recv_channel;
200 req_id = fcopy_transaction.recv_req_id;
202 icmsghdr = (struct icmsg_hdr *)
203 &recv_buffer[sizeof(struct vmbuspipe_hdr)];
205 if (channel->onchannel_callback == NULL)
207 * We have raced with util driver being unloaded;
212 icmsghdr->status = error;
213 icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
214 vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
215 VM_PKT_DATA_INBAND, 0);
218 void hv_fcopy_onchannelcallback(void *context)
220 struct vmbus_channel *channel = context;
223 struct hv_fcopy_hdr *fcopy_msg;
224 struct icmsg_hdr *icmsghdr;
225 struct icmsg_negotiate *negop = NULL;
227 int fcopy_srv_version;
229 if (fcopy_transaction.state > HVUTIL_READY)
232 vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
237 icmsghdr = (struct icmsg_hdr *)&recv_buffer[
238 sizeof(struct vmbuspipe_hdr)];
239 if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
240 util_fw_version = UTIL_FW_VERSION;
241 fcopy_srv_version = WIN8_SRV_VERSION;
242 vmbus_prep_negotiate_resp(icmsghdr, negop, recv_buffer,
243 util_fw_version, fcopy_srv_version);
245 fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
246 sizeof(struct vmbuspipe_hdr) +
247 sizeof(struct icmsg_hdr)];
250 * Stash away this global state for completing the
251 * transaction; note transactions are serialized.
254 fcopy_transaction.recv_len = recvlen;
255 fcopy_transaction.recv_channel = channel;
256 fcopy_transaction.recv_req_id = requestid;
257 fcopy_transaction.fcopy_msg = fcopy_msg;
259 if (fcopy_transaction.state < HVUTIL_READY) {
260 /* Userspace is not registered yet */
261 fcopy_respond_to_host(HV_E_FAIL);
264 fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
267 * Send the information to the user-level daemon.
269 schedule_work(&fcopy_send_work);
270 schedule_delayed_work(&fcopy_timeout_work,
271 HV_UTIL_TIMEOUT * HZ);
274 icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
275 vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
276 VM_PKT_DATA_INBAND, 0);
279 /* Callback when data is received from userspace */
280 static int fcopy_on_msg(void *msg, int len)
282 int *val = (int *)msg;
284 if (len != sizeof(int))
287 if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
288 return fcopy_handle_handshake(*val);
290 if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
294 * Complete the transaction by forwarding the result
295 * to the host. But first, cancel the timeout.
297 if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
298 fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
299 fcopy_respond_to_host(*val);
300 hv_poll_channel(fcopy_transaction.recv_channel,
307 static void fcopy_on_reset(void)
310 * The daemon has exited; reset the state.
312 fcopy_transaction.state = HVUTIL_DEVICE_INIT;
314 if (cancel_delayed_work_sync(&fcopy_timeout_work))
315 fcopy_respond_to_host(HV_E_FAIL);
316 complete(&release_event);
319 int hv_fcopy_init(struct hv_util_service *srv)
321 recv_buffer = srv->recv_buffer;
323 init_completion(&release_event);
325 * When this driver loads, the user level daemon that
326 * processes the host requests may not yet be running.
327 * Defer processing channel callbacks until the daemon
330 fcopy_transaction.state = HVUTIL_DEVICE_INIT;
332 hvt = hvutil_transport_init(fcopy_devname, 0, 0,
333 fcopy_on_msg, fcopy_on_reset);
340 void hv_fcopy_deinit(void)
342 fcopy_transaction.state = HVUTIL_DEVICE_DYING;
343 cancel_delayed_work_sync(&fcopy_timeout_work);
344 hvutil_transport_destroy(hvt);
345 wait_for_completion(&release_event);