Date: Sat, 14 Oct 1995 18:01:09 GMT From: nnd@itfs.nsk.su (Nickolay N. Dudorov) To: bugs@freebsd.org Subject: SLIP problem(s) in STABLE Message-ID: <DGGA1y.Dpr@itfs.nsk.su>
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It was already discovered that SLIP have some problems
in -current. I found some (same ?) problems in -stable.
1) After succesfully establishing a SLIP connection by
'slattach' on a line with modem and loosing/reestablishing carrier
I can't use that 'slX' interface due to permanent
'No route to host' messages.
Reading the sources of /sys/net/if_sl.c and /sys/kern/tty.c
shows that this message must results from:
/* /sys/net/if_sl.c - lines from 446 */
if ((sc->sc_ttyp->t_state & TS_CONNECTED) == 0) {
m_freem(m);
return (EHOSTUNREACH);
}
which in turn is a result of (!)-marked lines in
/* /sys/kern/tty.c - function ttymodem, lines from 1319 */
} else if (flag == 0) {
/*
* Lost carrier.
*/
CLR(tp->t_state, TS_CARR_ON);
if (ISSET(tp->t_state, TS_ISOPEN) &&
! !ISSET(tp->t_cflag, CLOCAL)) {
! SET(tp->t_state, TS_ZOMBIE);
! CLR(tp->t_state, TS_CONNECTED);
if (tp->t_session && tp->t_session->s_leader)
psignal(tp->t_session->s_leader, SIGHUP);
ttyflush(tp, FREAD | FWRITE);
return (0);
}
} else {
/*
* Carrier now on.
*/
SET(tp->t_state, TS_CARR_ON);
! if (!ISSET(tp->t_state, TS_ZOMBIE))
! SET(tp->t_state, TS_CONNECTED);
wakeup(TSA_CARR_ON(tp));
ttwakeup(tp);
ttwwakeup(tp);
}
As a temporary "solution" ;-( of this problem I make the
next change to /usr/src/sbin/slattach:
--- slattach.c.STABLE Sat Oct 14 22:16:12 1995
+++ slattach.c Sat Oct 14 22:55:55 1995
@@ -419,6 +419,18 @@
}
syslog(LOG_NOTICE, "Carrier now present on %s (sl%d)",
dev, unit);
+ /* This HACK clears TS_ZOMBIE flag and set */
+ /* TS_CONNECTED, which otherwise remains unset. */
+ tty.c_cflag |= CLOCAL;
+ if (tcsetattr(fd, TCSANOW, &tty) < 0) {
+ syslog(LOG_ERR, "tcsetattr(TCSAFLUSH): %m");
+ exit_handler(1);
+ }
+ tty.c_cflag &= ~CLOCAL;
+ if (tcsetattr(fd, TCSANOW, &tty) < 0) {
+ syslog(LOG_ERR, "tcsetattr(TCSAFLUSH): %m");
+ exit_handler(1);
+ }
}
}
setup_line(0);
After that I can use my SLIP connection (and this is a kind of
"correctness proof" of my problem analysis :-)
2) There are some "strangenesses(?)" in slattach behaviour
- 'slX' interface marked as 'UP' even before carrier is
established on a line;
- is it really necessary to 'fork' (in 'acquire_line()') every time
to run 'redial_cmd' (if there is any) ?
- it seens to me than "resetting to tty discipline" in this
'acquire_line' can't be done when redialing because there is
no carrier and switching to CLOCAL is done after that ?
Unfortunely I have not enough time (and/or knowledges) to find
answers to this questions (even in form of a HACKs) :-(
N.Dudorov
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