| Summary: | IPv6 with defaulted IIOP Endpoint includes loopback address in IOR | ||
|---|---|---|---|
| Product: | TAO | Reporter: | Phil Mesnier <mesnierp> |
| Component: | ORB | Assignee: | DOC Center Support List (internal) <tao-support> |
| Status: | NEW --- | ||
| Severity: | normal | ||
| Priority: | P3 | ||
| Version: | 1.6.3 | ||
| Hardware: | All | ||
| OS: | Linux | ||
Checked this with Martin, TAO_IIOP_Acceptor::probe_interfaces() should filter out all loopback interfaces if there are other non local loopback interfaces. If the system has no global ipv6 address then a loopback interface will be there. We use is_loopback from ACE_INET_Addr to detect loopback or not. In my case, while I have no non-local IPv6 interfaces, I do have non-local IPv4 interfaces. I think this is a very common configuration, and one that could lead to the problem of exporting an IOR that contains an explicit localhost address. I think the non-local test should be satisfied by any interface, either IPv6 or IPv4, unless IPv6 exclusivity is desired. Comment from Martin: this is to his idea what the code should do and does (at least on x.6.2 which he has on his system) OK. I found this comment while inspecting the code: // In case there are no non-local IPv6 ifs in the list only exclude // IPv4 loopback. // IPv6 loopback will be needed to successfully connect IPv6 clients // in a localhost environment. So I see now this behavior is by design. But I don't understand why this is the right thing to do. I can think of only one scenario where this might be useful, and that is on a Win32 host that has IPv6 enabled, but doesn't have a routable address configured. That seems like a rather narrow use case to modify the default behavior of the ORB. Perhaps there needs to be yet-another ORB option controlling this behavior? I think it is wrong to include a loopback endpoint by default in an IOR. I have found that on a windows XP host that currently has only IPv4 enabled, but ACE/TAO is built with ACE_HAS_IPV6 and ACE_USES_IPV4_IPV6_MIGRATION, a defaulted host will yield an error in the acceptor: -ORBListenEndpoint iiop://:12345 yields an error: TAO_IIOP_Acceptor::probe_interfaces found no usable addresses, def_type = 0 This is because the Acceptor's default_address_ member is initialized to IPv6 and this condition is later tested in probe_interfaces. I think that probe_interfaces in this case ought to allow IPv4-only in this situation if the ACE_USES_IPV4_IPV6_MIGRATION flag is set. |
The IIOP Acceptor is supposed to filter loopback and link-local addresses when provided an endpoint identifier with at least a defaulted hostname portion. For example, from the Hello test: Profile number: 2 IIOP Version: 1.2 Host Name: ::1 Port Number: 41149 Object Key len: 27 ::1 is the IPv6 representation of the loopback interface address. The IIOP Acceptor has significant logic to avoid other non-routable addresses, such as the IPv4 loopback and IPv6 link-local addresses. Somehow ::1 is slipping through the cracks.