Date: Sun, 28 Sep 1997 13:04:51 +1000 (EST) From: Ada T Lim <ada@not-enough.bandwidth.org> To: FreeBSD-gnats-submit@FreeBSD.ORG Subject: kern/4642: Treatment of unknown IP options breaks rfc2113 Message-ID: <199709280304.NAA02872@polya.blah.org> Resent-Message-ID: <199709280310.UAA01863@hub.freebsd.org>
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>Number: 4642
>Category: kern
>Synopsis: Treatment of unknown IP options breaks rfc2113
>Confidential: yes
>Severity: serious
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Sat Sep 27 20:10:00 PDT 1997
>Last-Modified:
>Originator: Ada Lim
>Organization:
>Release: FreeBSD 2.2-STABLE i386
>Environment:
>Description:
RFC 2113 (Router Alert Option) states:
2.2 Semantics
Hosts shall ignore this option. Routers that do not recognize this
option shall ignore it. Routers that recognize this option shall
ip_input.c:
[check options]
default:
goto bad;
.
.
.
bad:
ip->ip_len -= IP_VHL_HL(ip->ip_vhl) << 2; /* XXX icmp_error adds in hd
r length */
icmp_error(m, type, code, 0, 0);
ipstat.ips_badoptions++;
return (1);
This also breaks the handling of any new, experimental IP options as they
occur.
What would be preferable is to just allow default to fall-through and silently
ignore any unknown options.
>How-To-Repeat:
>Fix:
Remove the goto bad; :)
>Audit-Trail:
>Unformatted:
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