oss-sec mailing list archives
Re: Re: Some fun with tcp_wrappers
From: wietse () porcupine org (Wietse Venema)
Date: Thu, 16 Apr 2009 07:51:50 -0400 (EDT)
Tomas Hoger:
On Wed, 15 Apr 2009 14:53:22 -0400 (EDT) wietse () porcupine org (Wietse Venema) wrote:Wietse Venema:"test-hostsctl servicename unknown IP unknown" is what some applications do expecting tcp_wrappers to resolve IP to hostname.I think that it would be a mistake to change a documented API thatOn the other hand, if you could add a new function under a new name that does have the expected behavior, then there would be no confusion, no risk of cross-platform applications breaking, and I would withdraw my objection.That does not sound like a viable alternative and is likely to damage portability lot more, let me explain: - Application upstreams will not (should not) use any API that is vendor-specific extension and not included upstream. Even if there is some new upstream version, it might take years to get into wide enough use to applications to use new API, and result in incompatibility with old systems. - Applications change would be required. If that is done, there's little reason to change to new API instead of existing hosts_access.
Linux-specific modifications to a 20-year old API break cross-platform software. May I remind you that not all the world runs Linux. On the other hand, no cross-platform software will break if one adds a Linux-specific extension to the API. I haven't yet pointed out the problems with automatic hostname lookups from hosts_ctl(). One problem is that it breaks programs that must not do hostname lookups such as portmappers. Programs like the portmapper should not do hostname lookups, because that would result in infinite recursion when host lookups involve SUNRPC services such as NIS. Again, not all the world is Linux. Making platform-specific changes to a 20-year old API breaks cross-platform software in unexpected ways. Wietse
Current thread:
- Re: Re: Some fun with tcp_wrappers, (continued)
- Re: Re: Some fun with tcp_wrappers Wietse Venema (Apr 15)
- Re: Re: Some fun with tcp_wrappers Wietse Venema (Apr 15)
- Re: Re: Some fun with tcp_wrappers Steven M. Christey (Apr 15)
- Re: Re: Some fun with tcp_wrappers Tomas Hoger (Apr 16)
- Re: Re: Some fun with tcp_wrappers Wietse Venema (Apr 16)
- Re: Re: Some fun with tcp_wrappers Tomas Hoger (Apr 16)
- Re: Re: Some fun with tcp_wrappers Wietse Venema (Apr 16)
- Re: Re: Some fun with tcp_wrappers Steven M. Christey (Apr 24)
- Re: Re: Some fun with tcp_wrappers Tomas Hoger (Apr 28)
- Re: Re: Some fun with tcp_wrappers Tomas Hoger (Apr 16)
- Re: Re: Some fun with tcp_wrappers Wietse Venema (Apr 16)