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>
diff --git a/tools/hv/hv_fcopy_daemon.c b/tools/hv/hv_fcopy_daemon.c
new file mode 100644
index 0000000..4ecc4fd
--- /dev/null
+++ b/tools/hv/hv_fcopy_daemon.c
@@ -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);
+ }
+ }
+}