I have a tiny comment about the following change to the route(8)
command:
http://www.jp.FreeBSD.org/cgi/cvsweb.cgi/src/sbin/route/route.c.diff?r1=1.49&r2=1.50
In the commit log, the committer said
Fixed the -iface breakage introduced with the latest KAME merge
in revision 1.48. It is pretty valid and often feasible to use
a non-point-to-point interface as the gateway.
However, I'd say it is not a breakage, but just a fix of a bug.
Actually, the very old versions (before KAME) had a check not to allow
installing such a route to non-p2p-interfaces:
/* Look for this interface in the list */
for (ifr = ifconf.ifc_req,
ifr_end = (struct ifreq *)
(ifconf.ifc_buf + ifconf.ifc_len);
ifr < ifr_end;
ifr = (struct ifreq *) ((char *) &ifr->ifr_addr
+ MAX(ifr->ifr_addr.sa_len,
sizeof(ifr->ifr_addr)))) {
dl = (struct sockaddr_dl *)&ifr->ifr_addr;
if (ifr->ifr_addr.sa_family == AF_LINK
----> && (ifr->ifr_flags & IFF_POINTOPOINT)
&& !strncmp(s, dl->sdl_data, dl->sdl_nlen)
&& s[dl->sdl_nlen] == 0) {
(from http://www.jp.FreeBSD.org/cgi/cvsweb.cgi/src/sbin/route/route.c?rev=1.40.2.3)
However, the check is wrong, because ifr_flags is not a valid value in
this context (recall that the ifreq structure is a union of
sockaddr{}, an integer, etc.). Surprisingly, the bug introduced a
side-effect that made this type of route installation possible on
*every* type of interface; In this context, if_flags tend to be
0x123?, where 0x12 is AF_LINK, and 0x3? is a length of the sockaddr
for ordinary link (such as ethernet). Since IFF_POINTOPOINT is
0x0010, the check tended to misunderstand the interface is a
point-to-point one.
The change introduced with the KAME patch just intended to implement
the check in the original code correctly.
I don't have any particular opinion on the behavior itself, though.
If this is from a consensus in the FreeBSD community, I'm just okay
with the policy. I just would like to clarify the reason of the
KAME's change.
JINMEI, Tatuya
Communication Platform Lab.
Corporate R&D Center, Toshiba Corp.
[EMAIL PROTECTED]
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