sleep-util: move check_wakeup_type to sleep/sleep

1 files changed, 34 insertions, 0 deletions

diff --git a/src/sleep/sleep.c b/src/sleep/sleep.c
index 76b69f817a..f837e4d21a 100644
--- a/src/sleep/sleep.c
+++ b/src/sleep/sleep.c
@@ -176,6 +176,40 @@ static int write_state(FILE **f, char **states) {
         return r;
 }
 
+/* Return true if wakeup type is APM timer */
+static int check_wakeup_type(void) {
+        static const char dmi_object_path[] = "/sys/firmware/dmi/entries/1-0/raw";
+        uint8_t wakeup_type_byte, tablesize;
+        _cleanup_free_ char *buf = NULL;
+        size_t bufsize;
+        int r;
+
+        /* implementation via dmi/entries */
+        r = read_full_virtual_file(dmi_object_path, &buf, &bufsize);
+        if (r < 0)
+                return log_debug_errno(r, "Unable to read %s: %m", dmi_object_path);
+        if (bufsize < 25)
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Only read %zu bytes from %s (expected 25)", bufsize, dmi_object_path);
+
+        /* index 1 stores the size of table */
+        tablesize = (uint8_t) buf[1];
+        if (tablesize < 25)
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Table size lesser than the index[0x18] where waketype byte is available.");
+
+        wakeup_type_byte = (uint8_t) buf[24];
+        /* 0 is Reserved and 8 is AC Power Restored. As per table 12 in
+         * https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_3.4.0.pdf */
+        if (wakeup_type_byte >= 128)
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Expected value in range 0-127");
+
+        if (wakeup_type_byte == 3) {
+                log_debug("DMI BIOS System Information indicates wakeup type is APM Timer");
+                return true;
+        }
+
+        return false;
+}
+
 static int lock_all_homes(void) {
         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;