2 files changed, 165 insertions, 0 deletions
diff --git a/src/hibernate-resume/hibernate-resume-generator.c b/src/hibernate-resume/hibernate-resume-generator.c
new file mode 100644
index 0000000..8b127ca
--- /dev/null
+++ b/src/hibernate-resume/hibernate-resume-generator.c
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stdio.h>
+
+#include "alloc-util.h"
+#include "fstab-util.h"
+#include "generator.h"
+#include "log.h"
+#include "main-func.h"
+#include "mkdir.h"
+#include "proc-cmdline.h"
+#include "special.h"
+#include "string-util.h"
+#include "unit-name.h"
+#include "util.h"
+
+static const char *arg_dest = "/tmp";
+static char *arg_resume_device = NULL;
+static bool arg_noresume = false;
+
+STATIC_DESTRUCTOR_REGISTER(arg_resume_device, freep);
+
+static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
+
+        if (streq(key, "resume")) {
+                char *s;
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                s = fstab_node_to_udev_node(value);
+                if (!s)
+                        return log_oom();
+
+                free_and_replace(arg_resume_device, s);
+
+        } else if (streq(key, "noresume")) {
+                if (value) {
+                        log_warning("\"noresume\" kernel command line switch specified with an argument, ignoring.");
+                        return 0;
+                }
+
+                arg_noresume = true;
+        }
+
+        return 0;
+}
+
+static int process_resume(void) {
+        _cleanup_free_ char *name = NULL, *lnk = NULL;
+        int r;
+
+        if (!arg_resume_device)
+                return 0;
+
+        r = unit_name_from_path_instance("systemd-hibernate-resume", arg_resume_device, ".service", &name);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate unit name: %m");
+
+        lnk = strjoin(arg_dest, "/" SPECIAL_SYSINIT_TARGET ".wants/", name);
+        if (!lnk)
+                return log_oom();
+
+        mkdir_parents_label(lnk, 0755);
+        if (symlink(SYSTEM_DATA_UNIT_PATH "/systemd-hibernate-resume@.service", lnk) < 0)
+                return log_error_errno(errno, "Failed to create symlink %s: %m", lnk);
+
+        return 0;
+}
+
+static int run(int argc, char *argv[]) {
+        int r = 0;
+
+        log_setup_generator();
+
+        if (argc > 1 && argc != 4)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "This program takes three or no arguments.");
+
+        if (argc > 1)
+                arg_dest = argv[1];
+
+        /* Don't even consider resuming outside of initramfs. */
+        if (!in_initrd()) {
+                log_debug("Not running in an initrd, quitting.");
+                return 0;
+        }
+
+        r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
+        if (r < 0)
+                log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
+
+        if (arg_noresume) {
+                log_notice("Found \"noresume\" on the kernel command line, quitting.");
+                return 0;
+        }
+
+        return process_resume();
+}
+
+DEFINE_MAIN_FUNCTION(run);
diff --git a/src/hibernate-resume/hibernate-resume.c b/src/hibernate-resume/hibernate-resume.c
new file mode 100644
index 0000000..17e7cd1
--- /dev/null
+++ b/src/hibernate-resume/hibernate-resume.c
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <sys/stat.h>
+
+#include "alloc-util.h"
+#include "fileio.h"
+#include "log.h"
+#include "util.h"
+
+int main(int argc, char *argv[]) {
+        struct stat st;
+        const char *device;
+        _cleanup_free_ char *major_minor = NULL;
+        int r;
+
+        if (argc != 2) {
+                log_error("This program expects one argument.");
+                return EXIT_FAILURE;
+        }
+
+        log_setup_service();
+
+        umask(0022);
+
+        /* Refuse to run unless we are in an initrd() */
+        if (!in_initrd())
+                return EXIT_SUCCESS;
+
+        device = argv[1];
+
+        if (stat(device, &st) < 0) {
+                log_error_errno(errno, "Failed to stat '%s': %m", device);
+                return EXIT_FAILURE;
+        }
+
+        if (!S_ISBLK(st.st_mode)) {
+                log_error("Resume device '%s' is not a block device.", device);
+                return EXIT_FAILURE;
+        }
+
+        if (asprintf(&major_minor, "%d:%d", major(st.st_rdev), minor(st.st_rdev)) < 0) {
+                log_oom();
+                return EXIT_FAILURE;
+        }
+
+        r = write_string_file("/sys/power/resume", major_minor, WRITE_STRING_FILE_DISABLE_BUFFER);
+        if (r < 0) {
+                log_error_errno(r, "Failed to write '%s' to /sys/power/resume: %m", major_minor);
+                return EXIT_FAILURE;
+        }
+
+        /*
+         * The write above shall not return.
+         *
+         * However, failed resume is a normal condition (may mean that there is
+         * no hibernation image).
+         */
+
+        log_info("Could not resume from '%s' (%s).", device, major_minor);
+        return EXIT_SUCCESS;
+}