On Mon, 6 Sep 1999, Jan Wasserbauer wrote:
> Hi everyone on the list ..
>
> Part of checklogin() function:
> ...
> tv.tv_sec = 0;
> tv.tv_usec = 0;
>
> if (select (maxsock + 1, &rfds, NULL, NULL, &tv) <= 0)
> return;
>
> for (i = 0; i < listen_sock_num; i++)
> {
> if (!FD_ISSET (listen_sock[i], &rfds))
> continue;
>
> addrlen = sizeof (struct full_sockaddr_ax25);
> ret = accept (listen_sock[i], (struct sockaddr *) &newconn, &addrlen);
> ...
>
> This does work OK with any kernel below 2.2.12.
>
> With 2.2.12 accept() does not correctly fill sockaddr struct
> when tv.tv_sec=tv.tv_usec=0 (some binary mess instead of callsigns)
> It works when tv is nonzero.
>
> Reffering to select() man page tv=0 should cause select
> to check descriptors and exit immediately (and not just
> break accept() :) )
> To me it seems like kernel bug ..
This sounds very similar to the problem _some_ people have had with
LinuxNode on 2.2.x kernels. The most visible symptom of the bug is that an
incoming AX.25 connection to the node fails immediately and a message
about unsupported address family is logged in the syslogs.
Also seems that in these cases ax25d logs the connection as coming from
port (null).
At least in node the problem seems to be that a
getpeername(s, &addr, &len) system call returns with len==0 and bogus data
in the addr struct. The ax25d problem could be similarly failing
getsockname() but I haven't been able to verify that (see below).
It's noteworthy that this has happened to different people with different
2.2.x kernels, with different ax25d and node versions, different
distributions with different libc... For one guy this all suddenly went
away as he upgraded to RH6 but I've had reports on that platform too...
It's also noteworthy that I haven't been able to duplicate this error EVER
on ANY kernel version, including 2.2.12. This makes debugging very
difficult... :(
> My system - Slackware 4.0 (gcc2.7.2.3, libc5.4.46)
>
> If this is known bug I hope this at least saves some time
> to people wondering why their software doesn't work with 2.2.12.
--
--- Tomi Manninen / [EMAIL PROTECTED] / OH2BNS @ OH2RBI.FIN.EU ---
