Date: Wed, 8 Dec 2004 23:40:13 GMT From: dave baukus <dbaukus@chiaro.com> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/74876: Can not receive Hop by Hop options Message-ID: <200412082340.iB8NeD0i093473@www.freebsd.org> Resent-Message-ID: <200412082350.iB8NoNJ0029579@freefall.freebsd.org>
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>Number: 74876
>Category: kern
>Synopsis: Can not receive Hop by Hop options
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Wed Dec 08 23:50:23 GMT 2004
>Closed-Date:
>Last-Modified:
>Originator: dave baukus
>Release: 4.10
>Organization:
Chiaro Networks
>Environment:
FreeBSD kavachi 4.10-RELEASE FreeBSD 4.10-RELEASE #0:
Wed Dec 8 15:43:48 CST 2004dbaukus@krakatoa.chiaro.com:/home/dbaukus/kavachi-kern/compile/CHIAROS i386
>Description:
It is impossible for an application receive an IPv6
Hop By Hop option via the RFC 2293 API; a bug in the kernel prevents
this.
>How-To-Repeat:
Write a program that sends and receives IPv6 packets using the
RFC 2292 API; enable the receiving socket to extract the Hop by Hop
ancillary data. The kernel will not append the Hop by Hop options to
the socket() because of a bogus "privilege" check in ip6_savecontrol();
The check is bogus because it relies on curproc, this function
is executed from ip6_input via ip6intr() from softclock.
curproc, if not NULL, almost certainly has no relationship to the destination socket.
>Fix:
Remove the "privileged" check from the IN6P_HOPOPTS delivery in
ip6_savecontrol(); the setsockopt(...,IPV6_HOPOPTS,...) code
already checks suser() when the IN6P_HOPOPTS flag is set;
therefore, only a privileged socket will be able to receive these
options.
ip6_savecontrol () diff:
1372c1372
< if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0 && privileged) {
---
> if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) {
>Release-Note:
>Audit-Trail:
>Unformatted:
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