[REPOST PATCH xauth] Look for FamilyLocal if inet or inet6 address is loopback

[Julien Cristau]

> On Aug 14, 2013, at 8:08, Egbert Eich <eich at freedesktop.org> wrote:
> 
> > libxcb uses FamilyLocal authorization if the host name or IP in the
> > display string is from the loopback device. This patch adds the same
> > behavior to xauth.
> > This fixes a long standing problem that for ssh tunneled connections
> > a display variable of the form: localhost:<N>.<M> leads to correct
> > authorization when an X client is started but "xauth list $DISPLAY"
> > returns nothing.
> > 
> > Signed-off-by: Egbert Eich <eich at freedesktop.org>
> > ---
> > gethost.c | 40 +++++++++++++++++++++++++++++++++++-----
> > 1 file changed, 35 insertions(+), 5 deletions(-)
> > 
> > diff --git a/gethost.c b/gethost.c
> > index 10f6078..83fa95b 100644
> > --- a/gethost.c
> > +++ b/gethost.c
> > @@ -224,16 +224,36 @@ struct addrlist *get_address_info (
> > 	for (ai = firstai; ai != NULL; ai = ai->ai_next) {
> > 	    struct addrlist *duplicate;
> > 
> > +            len = 0;
> > 	    if (ai->ai_family == AF_INET) {
> > 		struct sockaddr_in *sin = (struct sockaddr_in *)ai->ai_addr;
> > 		src = &(sin->sin_addr);
> > -		len = sizeof(sin->sin_addr);
> > -		family = FamilyInternet;
> > +                if (*(in_addr_t *) src == htonl(INADDR_LOOPBACK)) {
> > +                    family = FamilyLocal;
> > +                    if (get_local_hostname (buf, sizeof buf)) {
> > +                        src = buf;
> > +                        len = strlen (buf);
> > +                    } else
> > +                        src = NULL;
> > +                } else {
> > +                    len = sizeof(sin->sin_addr);
> > +                    family = FamilyInternet;
> > +                }
> > 	    } else if (ai->ai_family == AF_INET6) {
> > 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)ai->ai_addr;
> > 		src = &(sin6->sin6_addr);
> > -		len = sizeof(sin6->sin6_addr);
> > -		family = FamilyInternet6;
> > +                if (IN6_IS_ADDR_V4MAPPED((struct sockaddr_in6 *)src)
> > +                    || IN6_IS_ADDR_LOOPBACK((struct sockaddr_in6 *)src)) {
> > +                    family = FamilyLocal;

I must be missing some context, but why are v4mapped addresses treated
as local?

Cheers,
Julien

> > +                    if (get_local_hostname (buf, sizeof buf)) {
> > +                        src = buf;
> > +                        len = strlen (buf);
> > +                    } else
> > +                        src = NULL;
> > +                } else {
> > +                    len = sizeof(sin6->sin6_addr);
> > +                    family = FamilyInternet6;
> > +                }
> > 	    }
> > 
> > 	    for(duplicate = retval; duplicate != NULL; duplicate = duplicate->next) {
> > @@ -272,7 +292,17 @@ struct addrlist *get_address_info (
> > #else
> > 	if (!get_inet_address (host, &hostinetaddr)) return NULL;
> > 	src = (char *) &hostinetaddr;
> > -	len = 4; /* sizeof inaddr.sin_addr, would fail on Cray */
> > +        if (*(in_addr_t *) src == htonl(INADDR_LOOPBACK)) {
> > +            family = FamilyLocal;
> > +            if (get_local_hostname (buf, sizeof buf)) {
> > +                src = buf;
> > +                len = strlen (buf);
> > +            } else {
> > +                len = 0;
> > +                src = NULL;
> > +            }
> > +        } else
> > +            len = 4; /* sizeof inaddr.sin_addr, would fail on Cray */
> > 	break;
> > #endif /* IPv6 */
> > #else
> > -- 
> > 1.8.1.4
> > 
> > _______________________________________________
> > xorg-devel at lists.x.org: X.Org development
> > Archives: http://lists.x.org/archives/xorg-devel
> > Info: http://lists.x.org/mailman/listinfo/xorg-devel
> > 
> 



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