Fix a major security problem with double-reverse lookup checking.

Changes with Apache 2.0.15-dev

  *) Fix a major security problem with double-reverse lookup checking.  

     Previously, a client connecting over IPv4 would not be matched 

     properly when the server had an IPv6 listening socket.  PR #7407

     [Taketo Kabe <kiabe@sra-tohoku.co.jp>]

  *) Change the way the beos MPM handles polling to allow it to stop and

     restart.  Problem was the sockets being polled were being reset by

     the select call, so once it had accepted a connection it was no

                conn->double_reverse = 1;

                return;

            }

#if APR_HAVE_IPV6

            /* match IPv4-mapped IPv6 addresses with IPv4 A record */

            if (conn->remote_addr->sa.sin.sin_family == APR_INET6 &&

                sa->sa.sin.sin_family == APR_INET &&

                IN6_IS_ADDR_V4MAPPED((struct in6_addr *)conn->remote_addr->ipaddr_ptr) &&

                !memcmp(&((struct in6_addr *)conn->remote_addr->ipaddr_ptr)->s6_addr[12],

                        sa->ipaddr_ptr,

                        sizeof (((struct in_addr *)0)->s_addr))) {

                conn->double_reverse = 1;

                return;

            }

#endif

            sa = sa->next;

        }

    }