[lwip-devel] [bug #29769] sys_check_timeouts: sys_now() may overflow

[Simon Goldschmidt]

URL:
  <http://savannah.nongnu.org/bugs/?29769>

                 Summary: sys_check_timeouts: sys_now() may overflow
                 Project: lwIP - A Lightweight TCP/IP stack
            Submitted by: goldsimon
            Submitted on: Di 04 Mai 2010 10:26:23 GMT
                Category: None
                Severity: 3 - Normal
              Item Group: None
                  Status: None
                 Privacy: Public
             Assigned to: None
             Open/Closed: Open
         Discussion Lock: Any
         Planned Release: 1.4.0
            lwIP version: CVS Head

    _______________________________________________________

Details:

For NO_SYS==1, sys_check_timeouts uses sys_now() time-difference to check for
timeouts. Now when the time wraps around (after 49-something days), no more
timers will get called. Possible solution:

> void
> sys_check_timeouts(void)
> {
>    struct sys_timeo *tmptimeout;
>    u32_t diff;
>    sys_timeout_handler h;
>    void *arg;
>    int had_one;
>    u32_t now;
> #if LWIP_DEBUG_TIMERNAMES
>    const char *handler_name;
> #endif /* LWIP_DEBUG_TIMERNAMES */
> 
>    now = sys_now();
>    if (next_timeout) {
>      /* @todo: wrap around? */
> // --------- new code
>      if (now < timeouts_last_time)
>        diff = ( 0xFFFFFFFF - timeouts_last_time ) + now + 1 ;
>      else
> // --------- end of new code
>      diff = now - timeouts_last_time;
> 




    _______________________________________________________

Reply to this item at:

  <http://savannah.nongnu.org/bugs/?29769>

_______________________________________________
  Nachricht geschickt von/durch Savannah
  http://savannah.nongnu.org/