Drivers: hv: Implement the file copy service

Implement the file copy service for Linux guests on Hyper-V. This permits the
host to copy a file (over VMBUS) into the guest. This facility is part of
"guest integration services" supported on the Windows platform.
Here is a link that provides additional details on this functionality:

http://technet.microsoft.com/en-us/library/dn464282.aspx

In V1 version of the patch I have addressed comments from
Olaf Hering <olaf@aepfle.de> and Dan Carpenter <dan.carpenter@oracle.com>

In V2 version of this patch I did some minor cleanup (making some globals
static). In V4 version of the patch I have addressed all of Olaf's
most recent set of comments/concerns.

In V5 version of the patch I had addressed Greg's most recent comments.
I would like to thank Greg for suggesting that I use misc device; it has
significantly simplified the code.

In V6 version of the patch I have cleaned up error message based on Olaf's
comments. I have also rebased the patch based on the current tip.

In this version of the patch, I have addressed the latest comments from Greg.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
K. Y. Srinivasan 2014-02-16 11:34:30 -08:00 committed by Greg Kroah-Hartman
parent e0270addae
commit 01325476d6
7 changed files with 682 additions and 2 deletions

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@ -5,4 +5,4 @@ obj-$(CONFIG_HYPERV_BALLOON) += hv_balloon.o
hv_vmbus-y := vmbus_drv.o \
hv.o connection.o channel.o \
channel_mgmt.o ring_buffer.o
hv_utils-y := hv_util.o hv_kvp.o hv_snapshot.o
hv_utils-y := hv_util.o hv_kvp.o hv_snapshot.o hv_fcopy.o

414
drivers/hv/hv_fcopy.c Normal file
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@ -0,0 +1,414 @@
/*
* An implementation of file copy service.
*
* Copyright (C) 2014, Microsoft, Inc.
*
* Author : K. Y. Srinivasan <ksrinivasan@novell.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/semaphore.h>
#include <linux/fs.h>
#include <linux/nls.h>
#include <linux/workqueue.h>
#include <linux/cdev.h>
#include <linux/hyperv.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
#include "hyperv_vmbus.h"
#define WIN8_SRV_MAJOR 1
#define WIN8_SRV_MINOR 1
#define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
/*
* Global state maintained for transaction that is being processed.
* For a class of integration services, including the "file copy service",
* the specified protocol is a "request/response" protocol which means that
* there can only be single outstanding transaction from the host at any
* given point in time. We use this to simplify memory management in this
* driver - we cache and process only one message at a time.
*
* While the request/response protocol is guaranteed by the host, we further
* ensure this by serializing packet processing in this driver - we do not
* read additional packets from the VMBUs until the current packet is fully
* handled.
*
* The transaction "active" state is set when we receive a request from the
* host and we cleanup this state when the transaction is completed - when we
* respond to the host with our response. When the transaction active state is
* set, we defer handling incoming packets.
*/
static struct {
bool active; /* transaction status - active or not */
int recv_len; /* number of bytes received. */
struct hv_fcopy_hdr *fcopy_msg; /* current message */
struct hv_start_fcopy message; /* sent to daemon */
struct vmbus_channel *recv_channel; /* chn we got the request */
u64 recv_req_id; /* request ID. */
void *fcopy_context; /* for the channel callback */
struct semaphore read_sema;
} fcopy_transaction;
static bool opened; /* currently device opened */
/*
* Before we can accept copy messages from the host, we need
* to handshake with the user level daemon. This state tracks
* if we are in the handshake phase.
*/
static bool in_hand_shake = true;
static void fcopy_send_data(void);
static void fcopy_respond_to_host(int error);
static void fcopy_work_func(struct work_struct *dummy);
static DECLARE_DELAYED_WORK(fcopy_work, fcopy_work_func);
static u8 *recv_buffer;
static void fcopy_work_func(struct work_struct *dummy)
{
/*
* If the timer fires, the user-mode component has not responded;
* process the pending transaction.
*/
fcopy_respond_to_host(HV_E_FAIL);
}
static int fcopy_handle_handshake(u32 version)
{
switch (version) {
case FCOPY_CURRENT_VERSION:
break;
default:
/*
* For now we will fail the registration.
* If and when we have multiple versions to
* deal with, we will be backward compatible.
* We will add this code when needed.
*/
return -EINVAL;
}
pr_info("FCP: user-mode registering done. Daemon version: %d\n",
version);
fcopy_transaction.active = false;
if (fcopy_transaction.fcopy_context)
hv_fcopy_onchannelcallback(fcopy_transaction.fcopy_context);
in_hand_shake = false;
return 0;
}
static void fcopy_send_data(void)
{
struct hv_start_fcopy *smsg_out = &fcopy_transaction.message;
int operation = fcopy_transaction.fcopy_msg->operation;
struct hv_start_fcopy *smsg_in;
/*
* The strings sent from the host are encoded in
* in utf16; convert it to utf8 strings.
* The host assures us that the utf16 strings will not exceed
* the max lengths specified. We will however, reserve room
* for the string terminating character - in the utf16s_utf8s()
* function we limit the size of the buffer where the converted
* string is placed to W_MAX_PATH -1 to guarantee
* that the strings can be properly terminated!
*/
switch (operation) {
case START_FILE_COPY:
memset(smsg_out, 0, sizeof(struct hv_start_fcopy));
smsg_out->hdr.operation = operation;
smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
UTF16_LITTLE_ENDIAN,
(__u8 *)smsg_out->file_name, W_MAX_PATH - 1);
utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
UTF16_LITTLE_ENDIAN,
(__u8 *)smsg_out->path_name, W_MAX_PATH - 1);
smsg_out->copy_flags = smsg_in->copy_flags;
smsg_out->file_size = smsg_in->file_size;
break;
default:
break;
}
up(&fcopy_transaction.read_sema);
return;
}
/*
* Send a response back to the host.
*/
static void
fcopy_respond_to_host(int error)
{
struct icmsg_hdr *icmsghdr;
u32 buf_len;
struct vmbus_channel *channel;
u64 req_id;
/*
* Copy the global state for completing the transaction. Note that
* only one transaction can be active at a time. This is guaranteed
* by the file copy protocol implemented by the host. Furthermore,
* the "transaction active" state we maintain ensures that there can
* only be one active transaction at a time.
*/
buf_len = fcopy_transaction.recv_len;
channel = fcopy_transaction.recv_channel;
req_id = fcopy_transaction.recv_req_id;
fcopy_transaction.active = false;
icmsghdr = (struct icmsg_hdr *)
&recv_buffer[sizeof(struct vmbuspipe_hdr)];
if (channel->onchannel_callback == NULL)
/*
* We have raced with util driver being unloaded;
* silently return.
*/
return;
icmsghdr->status = error;
icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
VM_PKT_DATA_INBAND, 0);
}
void hv_fcopy_onchannelcallback(void *context)
{
struct vmbus_channel *channel = context;
u32 recvlen;
u64 requestid;
struct hv_fcopy_hdr *fcopy_msg;
struct icmsg_hdr *icmsghdr;
struct icmsg_negotiate *negop = NULL;
int util_fw_version;
int fcopy_srv_version;
if (fcopy_transaction.active) {
/*
* We will defer processing this callback once
* the current transaction is complete.
*/
fcopy_transaction.fcopy_context = context;
return;
}
vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
&requestid);
if (recvlen <= 0)
return;
icmsghdr = (struct icmsg_hdr *)&recv_buffer[
sizeof(struct vmbuspipe_hdr)];
if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
util_fw_version = UTIL_FW_VERSION;
fcopy_srv_version = WIN8_SRV_VERSION;
vmbus_prep_negotiate_resp(icmsghdr, negop, recv_buffer,
util_fw_version, fcopy_srv_version);
} else {
fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
sizeof(struct vmbuspipe_hdr) +
sizeof(struct icmsg_hdr)];
/*
* Stash away this global state for completing the
* transaction; note transactions are serialized.
*/
fcopy_transaction.active = true;
fcopy_transaction.recv_len = recvlen;
fcopy_transaction.recv_channel = channel;
fcopy_transaction.recv_req_id = requestid;
fcopy_transaction.fcopy_msg = fcopy_msg;
/*
* Send the information to the user-level daemon.
*/
fcopy_send_data();
schedule_delayed_work(&fcopy_work, 5*HZ);
return;
}
icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
VM_PKT_DATA_INBAND, 0);
}
/*
* Create a char device that can support read/write for passing
* the payload.
*/
static ssize_t fcopy_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
void *src;
size_t copy_size;
int operation;
/*
* Wait until there is something to be read.
*/
if (down_interruptible(&fcopy_transaction.read_sema))
return -EINTR;
/*
* The channel may be rescinded and in this case, we will wakeup the
* the thread blocked on the semaphore and we will use the opened
* state to correctly handle this case.
*/
if (!opened)
return -ENODEV;
operation = fcopy_transaction.fcopy_msg->operation;
if (operation == START_FILE_COPY) {
src = &fcopy_transaction.message;
copy_size = sizeof(struct hv_start_fcopy);
if (count < copy_size)
return 0;
} else {
src = fcopy_transaction.fcopy_msg;
copy_size = sizeof(struct hv_do_fcopy);
if (count < copy_size)
return 0;
}
if (copy_to_user(buf, src, copy_size))
return -EFAULT;
return copy_size;
}
static ssize_t fcopy_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
int response = 0;
if (count != sizeof(int))
return -EINVAL;
if (copy_from_user(&response, buf, sizeof(int)))
return -EFAULT;
if (in_hand_shake) {
if (fcopy_handle_handshake(response))
return -EINVAL;
return sizeof(int);
}
/*
* Complete the transaction by forwarding the result
* to the host. But first, cancel the timeout.
*/
if (cancel_delayed_work_sync(&fcopy_work))
fcopy_respond_to_host(response);
return sizeof(int);
}
int fcopy_open(struct inode *inode, struct file *f)
{
/*
* The user level daemon that will open this device is
* really an extension of this driver. We can have only
* active open at a time.
*/
if (opened)
return -EBUSY;
/*
* The daemon is alive; setup the state.
*/
opened = true;
return 0;
}
int fcopy_release(struct inode *inode, struct file *f)
{
/*
* The daemon has exited; reset the state.
*/
in_hand_shake = true;
opened = false;
return 0;
}
static const struct file_operations fcopy_fops = {
.read = fcopy_read,
.write = fcopy_write,
.release = fcopy_release,
.open = fcopy_open,
};
static struct miscdevice fcopy_misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = "vmbus/hv_fcopy",
.fops = &fcopy_fops,
};
static int fcopy_dev_init(void)
{
return misc_register(&fcopy_misc);
}
static void fcopy_dev_deinit(void)
{
/*
* The device is going away - perhaps because the
* host has rescinded the channel. Setup state so that
* user level daemon can gracefully exit if it is blocked
* on the read semaphore.
*/
opened = false;
/*
* Signal the semaphore as the device is
* going away.
*/
up(&fcopy_transaction.read_sema);
misc_deregister(&fcopy_misc);
}
int hv_fcopy_init(struct hv_util_service *srv)
{
recv_buffer = srv->recv_buffer;
/*
* When this driver loads, the user level daemon that
* processes the host requests may not yet be running.
* Defer processing channel callbacks until the daemon
* has registered.
*/
fcopy_transaction.active = true;
sema_init(&fcopy_transaction.read_sema, 0);
return fcopy_dev_init();
}
void hv_fcopy_deinit(void)
{
cancel_delayed_work_sync(&fcopy_work);
fcopy_dev_deinit();
}

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@ -28,6 +28,7 @@
#include <linux/reboot.h>
#include <linux/hyperv.h>
#include "hyperv_vmbus.h"
#define SD_MAJOR 3
#define SD_MINOR 0
@ -82,6 +83,12 @@ static struct hv_util_service util_vss = {
.util_deinit = hv_vss_deinit,
};
static struct hv_util_service util_fcopy = {
.util_cb = hv_fcopy_onchannelcallback,
.util_init = hv_fcopy_init,
.util_deinit = hv_fcopy_deinit,
};
static void perform_shutdown(struct work_struct *dummy)
{
orderly_poweroff(true);
@ -401,6 +408,10 @@ static const struct hv_vmbus_device_id id_table[] = {
{ HV_VSS_GUID,
.driver_data = (unsigned long)&util_vss
},
/* File copy GUID */
{ HV_FCOPY_GUID,
.driver_data = (unsigned long)&util_fcopy
},
{ },
};

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@ -669,5 +669,9 @@ int vmbus_set_event(struct vmbus_channel *channel);
void vmbus_on_event(unsigned long data);
int hv_fcopy_init(struct hv_util_service *);
void hv_fcopy_deinit(void);
void hv_fcopy_onchannelcallback(void *);
#endif /* _HYPERV_VMBUS_H */

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@ -30,7 +30,6 @@
#include <linux/types.h>
#include <linux/scatterlist.h>
#include <linux/list.h>
#include <linux/uuid.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/completion.h>
@ -1049,6 +1048,17 @@ void vmbus_driver_unregister(struct hv_driver *hv_driver);
0xB7, 0x6B, 0x6F, 0xD0, 0xBE, 0x52, 0x8C, 0xDA \
}
/*
* Guest File Copy Service
* {34D14BE3-DEE4-41c8-9AE7-6B174977C192}
*/
#define HV_FCOPY_GUID \
.guid = { \
0xE3, 0x4B, 0xD1, 0x34, 0xE4, 0xDE, 0xC8, 0x41, \
0x9A, 0xE7, 0x6B, 0x17, 0x49, 0x77, 0xC1, 0x92 \
}
/*
* Common header for Hyper-V ICs
*/

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@ -25,6 +25,8 @@
#ifndef _UAPI_HYPERV_H
#define _UAPI_HYPERV_H
#include <linux/uuid.h>
/*
* Framework version for util services.
*/
@ -93,6 +95,50 @@ struct hv_vss_msg {
};
} __attribute__((packed));
/*
* Implementation of a host to guest copy facility.
*/
#define FCOPY_VERSION_0 0
#define FCOPY_CURRENT_VERSION FCOPY_VERSION_0
#define W_MAX_PATH 260
enum hv_fcopy_op {
START_FILE_COPY = 0,
WRITE_TO_FILE,
COMPLETE_FCOPY,
CANCEL_FCOPY,
};
struct hv_fcopy_hdr {
__u32 operation;
uuid_le service_id0; /* currently unused */
uuid_le service_id1; /* currently unused */
} __attribute__((packed));
#define OVER_WRITE 0x1
#define CREATE_PATH 0x2
struct hv_start_fcopy {
struct hv_fcopy_hdr hdr;
__u16 file_name[W_MAX_PATH];
__u16 path_name[W_MAX_PATH];
__u32 copy_flags;
__u64 file_size;
} __attribute__((packed));
/*
* The file is chunked into fragments.
*/
#define DATA_FRAGMENT (6 * 1024)
struct hv_do_fcopy {
struct hv_fcopy_hdr hdr;
__u64 offset;
__u32 size;
__u8 data[DATA_FRAGMENT];
};
/*
* An implementation of HyperV key value pair (KVP) functionality for Linux.
*

195
tools/hv/hv_fcopy_daemon.c Normal file
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@ -0,0 +1,195 @@
/*
* An implementation of host to guest copy functionality for Linux.
*
* Copyright (C) 2014, Microsoft, Inc.
*
* Author : K. Y. Srinivasan <kys@microsoft.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/poll.h>
#include <linux/types.h>
#include <linux/kdev_t.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <linux/hyperv.h>
#include <syslog.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
static int target_fd;
static char target_fname[W_MAX_PATH];
static int hv_start_fcopy(struct hv_start_fcopy *smsg)
{
int error = HV_E_FAIL;
char *q, *p;
/*
* If possile append a path seperator to the path.
*/
if (strlen((char *)smsg->path_name) < (W_MAX_PATH - 2))
strcat((char *)smsg->path_name, "/");
p = (char *)smsg->path_name;
snprintf(target_fname, sizeof(target_fname), "%s/%s",
(char *)smsg->path_name, smsg->file_name);
syslog(LOG_INFO, "Target file name: %s", target_fname);
/*
* Check to see if the path is already in place; if not,
* create if required.
*/
while ((q = strchr(p, '/')) != NULL) {
if (q == p) {
p++;
continue;
}
*q = '\0';
if (access((char *)smsg->path_name, F_OK)) {
if (smsg->copy_flags & CREATE_PATH) {
if (mkdir((char *)smsg->path_name, 0755)) {
syslog(LOG_ERR, "Failed to create %s",
(char *)smsg->path_name);
goto done;
}
} else {
syslog(LOG_ERR, "Invalid path: %s",
(char *)smsg->path_name);
goto done;
}
}
p = q + 1;
*q = '/';
}
if (!access(target_fname, F_OK)) {
syslog(LOG_INFO, "File: %s exists", target_fname);
if (!smsg->copy_flags & OVER_WRITE)
goto done;
}
target_fd = open(target_fname, O_RDWR | O_CREAT | O_CLOEXEC, 0744);
if (target_fd == -1) {
syslog(LOG_INFO, "Open Failed: %s", strerror(errno));
goto done;
}
error = 0;
done:
return error;
}
static int hv_copy_data(struct hv_do_fcopy *cpmsg)
{
ssize_t bytes_written;
bytes_written = pwrite(target_fd, cpmsg->data, cpmsg->size,
cpmsg->offset);
if (bytes_written != cpmsg->size)
return HV_E_FAIL;
return 0;
}
static int hv_copy_finished(void)
{
close(target_fd);
return 0;
}
static int hv_copy_cancel(void)
{
close(target_fd);
unlink(target_fname);
return 0;
}
int main(void)
{
int fd, fcopy_fd, len;
int error;
int version = FCOPY_CURRENT_VERSION;
char *buffer[4096 * 2];
struct hv_fcopy_hdr *in_msg;
if (daemon(1, 0)) {
syslog(LOG_ERR, "daemon() failed; error: %s", strerror(errno));
exit(EXIT_FAILURE);
}
openlog("HV_FCOPY", 0, LOG_USER);
syslog(LOG_INFO, "HV_FCOPY starting; pid is:%d", getpid());
fcopy_fd = open("/dev/vmbus/hv_fcopy", O_RDWR);
if (fcopy_fd < 0) {
syslog(LOG_ERR, "open /dev/vmbus/hv_fcopy failed; error: %d %s",
errno, strerror(errno));
exit(EXIT_FAILURE);
}
/*
* Register with the kernel.
*/
if ((write(fcopy_fd, &version, sizeof(int))) != sizeof(int)) {
syslog(LOG_ERR, "Registration failed: %s", strerror(errno));
exit(EXIT_FAILURE);
}
while (1) {
/*
* In this loop we process fcopy messages after the
* handshake is complete.
*/
len = pread(fcopy_fd, buffer, (4096 * 2), 0);
if (len < 0) {
syslog(LOG_ERR, "pread failed: %s", strerror(errno));
exit(EXIT_FAILURE);
}
in_msg = (struct hv_fcopy_hdr *)buffer;
switch (in_msg->operation) {
case START_FILE_COPY:
error = hv_start_fcopy((struct hv_start_fcopy *)in_msg);
break;
case WRITE_TO_FILE:
error = hv_copy_data((struct hv_do_fcopy *)in_msg);
break;
case COMPLETE_FCOPY:
error = hv_copy_finished();
break;
case CANCEL_FCOPY:
error = hv_copy_cancel();
break;
default:
syslog(LOG_ERR, "Unknown operation: %d",
in_msg->operation);
}
if (pwrite(fcopy_fd, &error, sizeof(int), 0) != sizeof(int)) {
syslog(LOG_ERR, "pwrite failed: %s", strerror(errno));
exit(EXIT_FAILURE);
}
}
}