crond: fix reboot special timecron_changes

The 'reboot' special time didn't work because the file to check
for a reboot couldn't be created.  And in any case, the mechanism
used on Linux wouldn't work: Windows has no /var/run directory
which is cleared on reboot.

The crond.reboot file is now placed in the cron directory.  If it
doesn't exist when crond starts, it's created but the reboot job
(if any) isn't run.  If the file exists its modification time is
compared with the time of the current boot.  If it's older update
its time and run the reboot job.

Adds 144-224 bytes.

1 files changed, 31 insertions, 0 deletions

diff --git a/miscutils/crond.c b/miscutils/crond.c
index 7278a1ad4..4bfe4a6c0 100644
--- a/miscutils/crond.c
+++ b/miscutils/crond.c
@@ -103,7 +103,11 @@
 
 #define CRON_DIR        CONFIG_FEATURE_CROND_DIR
 #define CRONTABS        CONFIG_FEATURE_CROND_DIR "/crontabs"
+#if ENABLE_PLATFORM_MINGW32
+#define CRON_REBOOT     "crond.reboot"
+#else
 #define CRON_REBOOT     CONFIG_PID_FILE_PATH "/crond.reboot"
+#endif
 #ifndef SENDMAIL
 # define SENDMAIL       "sendmail"
 #endif
@@ -176,6 +180,7 @@ struct globals {
         const char *crontab_dir_name; /* = CRONTABS; */
 #if ENABLE_PLATFORM_MINGW32
         const char *crondir_name; /* = CRON_DIR; */
+        const char *reboot_name;
 #endif
         CronFile *cron_files;
         char *default_shell;
@@ -1061,6 +1066,30 @@ static void flag_starting_jobs(time_t t1, time_t t2)
 #if ENABLE_FEATURE_CROND_SPECIAL_TIMES
 static int touch_reboot_file(void)
 {
+#if ENABLE_PLATFORM_MINGW32
+        struct stat st;
+        struct timespec now;
+        long long ms_since_boot;
+        const struct timespec ts[2] = {{0, UTIME_NOW}, {0, UTIME_NOW}};
+        int fd, ret = 0;
+
+        if (stat(G.reboot_name, &st) == 0) {
+                clock_gettime(CLOCK_REALTIME, &now);
+                ms_since_boot = GetTickCount64();
+
+                if (st.st_mtim.tv_sec < now.tv_sec - ms_since_boot/1000) {
+                        // crond.reboot predates boot time, update it and run job
+                        utimensat(AT_FDCWD, G.reboot_name, ts, 0);
+                        ret = 1;
+                }
+        } else {
+                // crond.reboot doesn't exist, create it, but don't run job
+                fd = open(G.reboot_name, O_WRONLY | O_CREAT | O_EXCL | O_TRUNC, 0000);
+                if (fd >= 0)
+                        close(fd);
+        }
+        return ret;
+#else
         int fd = open(CRON_REBOOT, O_WRONLY | O_CREAT | O_EXCL | O_TRUNC, 0000);
         if (fd >= 0) {
                 close(fd);
@@ -1068,6 +1097,7 @@ static int touch_reboot_file(void)
         }
         /* File (presumably) exists - this is not the first run after reboot */
         return 0;
+#endif
 }
 #endif
 
@@ -1242,6 +1272,7 @@ int crond_main(int argc UNUSED_PARAM, char **argv)
                 free((void *)G.crondir_name);
                 G.crondir_name = dirname(xstrdup(G.crontab_dir_name));
         }
+        G.reboot_name = concat_path_file(G.crondir_name, CRON_REBOOT);
 #endif
 
         if (!(opts & OPT_f)) {