Re: [SSI-devel] strange inetd/tftp behavior

[Christian L. <ly...@po...>]

Last try today...

c3sl2:/boot#  /usr/sbin/inetd -d /etc/inetd.conf=20
ADD : smtp proto=3Dtcp, wait.max=3D0.40, user.group=3Dmail.(null) builtin=
=3D0=20
server=3D/usr/sbin/exim
ADD : tftp proto=3Dudp, wait.max=3D1.40, user.group=3Dnobody.(null) built=
in=3D0=20
server=3D/usr/sbin/tcpd
someone wants tftp
73103 execl /usr/sbin/tcpd
73103 reaped, status 0    <--- transfer ok

them inetd never saw other connection (but of course there are other trie=
s!).=0D


c3sl2:/boot# strace /usr/sbin/inetd -d /etc/inetd.conf
[...]
rt_sigaction(SIGPIPE, {SIG_IGN}, NULL, 8) =3D 0
select(6, [4 5], NULL, NULL, NULL)      =3D 1 (in [5])
write(2, "someone wants tftp\n", 19someone wants tftp
)    =3D 19
rt_sigprocmask(SIG_BLOCK, [HUP ALRM CHLD], NULL, 8) =3D 0
gettimeofday({1043443741, 445557}, NULL) =3D 0
fork()                                  =3D 73122
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) =3D 0
select(6, [4], NULL, NULL, NULL73122 execl /usr/sbin/tcpd
)        =3D ? ERESTARTNOHAND (To be restarted)
--- SIGCHLD (Child exited) ---
wait4(-1, [WIFEXITED(s) && WEXITSTATUS(s) =3D=3D 0], WNOHANG, NULL) =3D 7=
3122
write(2, "73122 reaped, status 0\n", 2373122 reaped, status 0
) =3D 23
wait4(-1, 0xbffff870, WNOHANG, NULL)    =3D -1 ECHILD (No child processes=
)
sigreturn()                             =3D ? (mask now [])
select(6, [4], NULL, NULL, NULL <unfinished ...>    <---crtl+c

tcpdump -i eth0 shows that are others tftp requests but inetd couldnt see=
=20
them

=09Any clues?


On Friday 24 January 2003 19:11, you wrote:
> Christian Lyra wrote:
> > HI,
> >
> >>Everytime a node joins (actually changes its membership state),
> >>SIGCLUSTER (stolen from one of the realtime signals) gets sent to all
> >>the processes on the system. (This was a holdover from the UnixWare
> >>implementation.) Aneesh suspects your inetd is dying because of this.=
 If
> >>you strace your inetd and it is dying because it is receiving a signa=
l
> >>(49 I believe) then Aneesh is correct.
> >
> > =09Thanks for the explanation, but I think the problem is not with
> > SIGCLUSTER, because I can reproduce the problem using just the master
> > node, and another (non-cluster) machine with a tftp client (of course=
,
> > all other nodes are turned offf)! So there's no SIGCLUSTER signals. F=
tpd
> > dies(?) after the first transfer. I try to setup a telnetd just to se=
e if
> > it die too but this not happens! just tftpd die :-(
>
> The ftp/tftp transfer completes successfully and then the daemon dies?
> Or does the daemon die partway through thr transfer.
>
> The daemon dying after a successful transfer may not be bad. Most inetd
> sub-daemons do if they don't receive another request after a given time=
=2E
>
> If inetd is running and the tftpd is dead, then a new tftpd should be
> spawned. The problem then might be inetd is not seeing its children die=
=2E
>   If you run strace on inetd during the successful operation followed b=
y
> the failure maybe we could figure out what is going wrong.
>
> John Byrne
>
--=20
Christian Lyra
POP-PR - RNP

  Who can tell the secrets of their hearts and minds?=20
  The answer exists only in Tao.=20
=09=09=09=09=09=09The Tao Of Programing