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-rw-r--r--src/shared/reboot-util.c196
1 files changed, 196 insertions, 0 deletions
diff --git a/src/shared/reboot-util.c b/src/shared/reboot-util.c
new file mode 100644
index 0000000..62ff697
--- /dev/null
+++ b/src/shared/reboot-util.c
@@ -0,0 +1,196 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <stdint.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#if HAVE_XENCTRL
+#define __XEN_INTERFACE_VERSION__ 0x00040900
+#include <xen/xen.h>
+#include <xen/kexec.h>
+#include <xen/sys/privcmd.h>
+#endif
+
+#include "alloc-util.h"
+#include "errno-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "log.h"
+#include "proc-cmdline.h"
+#include "raw-reboot.h"
+#include "reboot-util.h"
+#include "string-util.h"
+#include "umask-util.h"
+#include "virt.h"
+
+int update_reboot_parameter_and_warn(const char *parameter, bool keep) {
+ int r;
+
+ if (isempty(parameter)) {
+ if (keep)
+ return 0;
+
+ if (unlink("/run/systemd/reboot-param") < 0) {
+ if (errno == ENOENT)
+ return 0;
+
+ return log_warning_errno(errno, "Failed to unlink reboot parameter file: %m");
+ }
+
+ return 0;
+ }
+
+ WITH_UMASK(0022) {
+ r = write_string_file("/run/systemd/reboot-param", parameter,
+ WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_ATOMIC);
+ if (r < 0)
+ return log_warning_errno(r, "Failed to write reboot parameter file: %m");
+ }
+
+ return 0;
+}
+
+int read_reboot_parameter(char **parameter) {
+ int r;
+
+ assert(parameter);
+
+ r = read_one_line_file("/run/systemd/reboot-param", parameter);
+ if (r < 0 && r != -ENOENT)
+ return log_debug_errno(r, "Failed to read /run/systemd/reboot-param: %m");
+
+ return 0;
+}
+
+int reboot_with_parameter(RebootFlags flags) {
+ int r;
+
+ /* Reboots the system with a parameter that is read from /run/systemd/reboot-param. Returns 0 if
+ * REBOOT_DRY_RUN was set and the actual reboot operation was hence skipped. If REBOOT_FALLBACK is
+ * set and the reboot with parameter doesn't work out a fallback to classic reboot() is attempted. If
+ * REBOOT_FALLBACK is not set, 0 is returned instead, which should be considered indication for the
+ * caller to fall back to reboot() on its own, or somehow else deal with this. If REBOOT_LOG is
+ * specified will log about what it is going to do, as well as all errors. */
+
+ if (detect_container() == 0) {
+ _cleanup_free_ char *parameter = NULL;
+
+ r = read_one_line_file("/run/systemd/reboot-param", &parameter);
+ if (r < 0 && r != -ENOENT)
+ log_full_errno(flags & REBOOT_LOG ? LOG_WARNING : LOG_DEBUG, r,
+ "Failed to read reboot parameter file, ignoring: %m");
+
+ if (!isempty(parameter)) {
+ log_full(flags & REBOOT_LOG ? LOG_INFO : LOG_DEBUG,
+ "Rebooting with argument '%s'.", parameter);
+
+ if (flags & REBOOT_DRY_RUN)
+ return 0;
+
+ (void) raw_reboot(LINUX_REBOOT_CMD_RESTART2, parameter);
+
+ log_full_errno(flags & REBOOT_LOG ? LOG_WARNING : LOG_DEBUG, errno,
+ "Failed to reboot with parameter, retrying without: %m");
+ }
+ }
+
+ if (!(flags & REBOOT_FALLBACK))
+ return 0;
+
+ log_full(flags & REBOOT_LOG ? LOG_INFO : LOG_DEBUG, "Rebooting.");
+
+ if (flags & REBOOT_DRY_RUN)
+ return 0;
+
+ (void) reboot(RB_AUTOBOOT);
+
+ return log_full_errno(flags & REBOOT_LOG ? LOG_ERR : LOG_DEBUG, errno, "Failed to reboot: %m");
+}
+
+bool shall_restore_state(void) {
+ static int cached = -1;
+ bool b = true; /* If nothing specified or the check fails, then defaults to true. */
+ int r;
+
+ if (cached >= 0)
+ return cached;
+
+ r = proc_cmdline_get_bool("systemd.restore_state", PROC_CMDLINE_TRUE_WHEN_MISSING, &b);
+ if (r < 0)
+ log_debug_errno(r, "Failed to parse systemd.restore_state= kernel command line option, ignoring: %m");
+
+ return (cached = b);
+}
+
+static int xen_kexec_loaded(void) {
+#if HAVE_XENCTRL
+ _cleanup_close_ int privcmd_fd = -EBADF, buf_fd = -EBADF;
+ xen_kexec_status_t *buffer;
+ size_t size;
+ int r;
+
+ if (access("/proc/xen", F_OK) < 0) {
+ if (errno == ENOENT)
+ return -EOPNOTSUPP;
+ return log_debug_errno(errno, "Unable to test whether /proc/xen exists: %m");
+ }
+
+ size = page_size();
+ if (sizeof(xen_kexec_status_t) > size)
+ return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "page_size is too small for hypercall");
+
+ privcmd_fd = open("/dev/xen/privcmd", O_RDWR|O_CLOEXEC);
+ if (privcmd_fd < 0)
+ return log_debug_errno(errno, "Cannot access /dev/xen/privcmd: %m");
+
+ buf_fd = open("/dev/xen/hypercall", O_RDWR|O_CLOEXEC);
+ if (buf_fd < 0)
+ return log_debug_errno(errno, "Cannot access /dev/xen/hypercall: %m");
+
+ buffer = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_SHARED, buf_fd, 0);
+ if (buffer == MAP_FAILED)
+ return log_debug_errno(errno, "Cannot allocate buffer for hypercall: %m");
+
+ *buffer = (xen_kexec_status_t) {
+ .type = KEXEC_TYPE_DEFAULT,
+ };
+
+ privcmd_hypercall_t call = {
+ .op = __HYPERVISOR_kexec_op,
+ .arg = {
+ KEXEC_CMD_kexec_status,
+ PTR_TO_UINT64(buffer),
+ },
+ };
+
+ r = RET_NERRNO(ioctl(privcmd_fd, IOCTL_PRIVCMD_HYPERCALL, &call));
+ if (r < 0)
+ log_debug_errno(r, "kexec_status failed: %m");
+
+ munmap(buffer, size);
+
+ return r;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+bool kexec_loaded(void) {
+ _cleanup_free_ char *s = NULL;
+ int r;
+
+ r = xen_kexec_loaded();
+ if (r >= 0)
+ return r;
+
+ r = read_one_line_file("/sys/kernel/kexec_loaded", &s);
+ if (r < 0) {
+ if (r != -ENOENT)
+ log_debug_errno(r, "Unable to read /sys/kernel/kexec_loaded, ignoring: %m");
+ return false;
+ }
+
+ return s[0] == '1';
+}