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-rw-r--r--tools/hv/hv_fcopy_daemon.c266
1 files changed, 266 insertions, 0 deletions
diff --git a/tools/hv/hv_fcopy_daemon.c b/tools/hv/hv_fcopy_daemon.c
new file mode 100644
index 000000000..16d629b22
--- /dev/null
+++ b/tools/hv/hv_fcopy_daemon.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * An implementation of host to guest copy functionality for Linux.
+ *
+ * Copyright (C) 2014, Microsoft, Inc.
+ *
+ * Author : K. Y. Srinivasan <kys@microsoft.com>
+ */
+
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <linux/hyperv.h>
+#include <linux/limits.h>
+#include <syslog.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <getopt.h>
+
+static int target_fd;
+static char target_fname[PATH_MAX];
+static unsigned long long filesize;
+
+static int hv_start_fcopy(struct hv_start_fcopy *smsg)
+{
+ int error = HV_E_FAIL;
+ char *q, *p;
+
+ filesize = 0;
+ p = (char *)smsg->path_name;
+ snprintf(target_fname, sizeof(target_fname), "%s/%s",
+ (char *)smsg->path_name, (char *)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)) {
+ error = HV_ERROR_ALREADY_EXISTS;
+ goto done;
+ }
+ }
+
+ target_fd = open(target_fname,
+ O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0744);
+ if (target_fd == -1) {
+ syslog(LOG_INFO, "Open Failed: %s", strerror(errno));
+ goto done;
+ }
+
+ error = 0;
+done:
+ if (error)
+ target_fname[0] = '\0';
+ return error;
+}
+
+static int hv_copy_data(struct hv_do_fcopy *cpmsg)
+{
+ ssize_t bytes_written;
+ int ret = 0;
+
+ bytes_written = pwrite(target_fd, cpmsg->data, cpmsg->size,
+ cpmsg->offset);
+
+ filesize += cpmsg->size;
+ if (bytes_written != cpmsg->size) {
+ switch (errno) {
+ case ENOSPC:
+ ret = HV_ERROR_DISK_FULL;
+ break;
+ default:
+ ret = HV_E_FAIL;
+ break;
+ }
+ syslog(LOG_ERR, "pwrite failed to write %llu bytes: %ld (%s)",
+ filesize, (long)bytes_written, strerror(errno));
+ }
+
+ return ret;
+}
+
+/*
+ * Reset target_fname to "" in the two below functions for hibernation: if
+ * the fcopy operation is aborted by hibernation, the daemon should remove the
+ * partially-copied file; to achieve this, the hv_utils driver always fakes a
+ * CANCEL_FCOPY message upon suspend, and later when the VM resumes back,
+ * the daemon calls hv_copy_cancel() to remove the file; if a file is copied
+ * successfully before suspend, hv_copy_finished() must reset target_fname to
+ * avoid that the file can be incorrectly removed upon resume, since the faked
+ * CANCEL_FCOPY message is spurious in this case.
+ */
+static int hv_copy_finished(void)
+{
+ close(target_fd);
+ target_fname[0] = '\0';
+ return 0;
+}
+static int hv_copy_cancel(void)
+{
+ close(target_fd);
+ if (strlen(target_fname) > 0) {
+ unlink(target_fname);
+ target_fname[0] = '\0';
+ }
+ return 0;
+
+}
+
+void print_usage(char *argv[])
+{
+ fprintf(stderr, "Usage: %s [options]\n"
+ "Options are:\n"
+ " -n, --no-daemon stay in foreground, don't daemonize\n"
+ " -h, --help print this help\n", argv[0]);
+}
+
+int main(int argc, char *argv[])
+{
+ int fcopy_fd = -1;
+ int error;
+ int daemonize = 1, long_index = 0, opt;
+ int version = FCOPY_CURRENT_VERSION;
+ union {
+ struct hv_fcopy_hdr hdr;
+ struct hv_start_fcopy start;
+ struct hv_do_fcopy copy;
+ __u32 kernel_modver;
+ } buffer = { };
+ int in_handshake;
+
+ static struct option long_options[] = {
+ {"help", no_argument, 0, 'h' },
+ {"no-daemon", no_argument, 0, 'n' },
+ {0, 0, 0, 0 }
+ };
+
+ while ((opt = getopt_long(argc, argv, "hn", long_options,
+ &long_index)) != -1) {
+ switch (opt) {
+ case 'n':
+ daemonize = 0;
+ break;
+ case 'h':
+ default:
+ print_usage(argv);
+ exit(EXIT_FAILURE);
+ }
+ }
+
+ if (daemonize && daemon(1, 0)) {
+ syslog(LOG_ERR, "daemon() failed; error: %s", strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+
+ openlog("HV_FCOPY", 0, LOG_USER);
+ syslog(LOG_INFO, "starting; pid is:%d", getpid());
+
+reopen_fcopy_fd:
+ if (fcopy_fd != -1)
+ close(fcopy_fd);
+ /* Remove any possible partially-copied file on error */
+ hv_copy_cancel();
+ in_handshake = 1;
+ 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.
+ */
+ ssize_t len;
+
+ len = pread(fcopy_fd, &buffer, sizeof(buffer), 0);
+ if (len < 0) {
+ syslog(LOG_ERR, "pread failed: %s", strerror(errno));
+ goto reopen_fcopy_fd;
+ }
+
+ if (in_handshake) {
+ if (len != sizeof(buffer.kernel_modver)) {
+ syslog(LOG_ERR, "invalid version negotiation");
+ exit(EXIT_FAILURE);
+ }
+ in_handshake = 0;
+ syslog(LOG_INFO, "kernel module version: %u",
+ buffer.kernel_modver);
+ continue;
+ }
+
+ switch (buffer.hdr.operation) {
+ case START_FILE_COPY:
+ error = hv_start_fcopy(&buffer.start);
+ break;
+ case WRITE_TO_FILE:
+ error = hv_copy_data(&buffer.copy);
+ break;
+ case COMPLETE_FCOPY:
+ error = hv_copy_finished();
+ break;
+ case CANCEL_FCOPY:
+ error = hv_copy_cancel();
+ break;
+
+ default:
+ error = HV_E_FAIL;
+ syslog(LOG_ERR, "Unknown operation: %d",
+ buffer.hdr.operation);
+
+ }
+
+ /*
+ * pwrite() may return an error due to the faked CANCEL_FCOPY
+ * message upon hibernation. Ignore the error by resetting the
+ * dev file, i.e. closing and re-opening it.
+ */
+ if (pwrite(fcopy_fd, &error, sizeof(int), 0) != sizeof(int)) {
+ syslog(LOG_ERR, "pwrite failed: %s", strerror(errno));
+ goto reopen_fcopy_fd;
+ }
+ }
+}