On 10/11/2010 8:01 AM, Adam Tkac wrote: > Hello all, > > I would like to ask you for the reason why there are separate versions > of libdns, libisc & friends, called "export libraries" in BIND 9.7 > series. > > If I understand correctly those export libs are supposed to be used > from non-BIND9 applications and some methods are lightweight compared > to full-featured BIND9 versions. In my opinion it's good idea to offer > two versions of certain methods. However I don't understand why those > methods need to be in separate library and, which is even worse, this > library has the same name as full featured BIND9 lib. It is the best > way to various run-time issues, like unresolved symbols. Another issue > is that isc-config.sh utility (which is used to determine CFLAGS, > LDFLAGS etc) has no support for this dual-library setup. > > In my opinion export libs and standard libs should be merged together > or should be renamed (for example to libdns-export.so). I must note > rename is probably worse case because dynamic linker can randomly > pick methods with same name from libdns.so or from libdns-export.so. > I think the best solution is to merge two libs into one and select > methods via preprocessor flag (-DBIND9). The merged library will > look like: > > isc/namespace.h: > > #ifdef BIND9 > #define isc_something isc__something > #endif > > libisc.so: > isc_something > isc__something > > So there will be no runtime issues. May I ask you if you can change > current dynamic libraries setup somehow? I can prepare the patches, > if you are interested. > > Regards, Adam >
Noone seems to have responded to you on this, so I thought I should. Contrary to what you think, these libraries are really designed for BIND9 usage. The libraries are designed to separate different functional areas. The libisc library are basically a generic set of functions which operate as a layer between BIND9 and the O/S and allow almost all of the O/S specific behaviors to reside there but are not meant to have anything to do with handling dns-specific areas. That's in the libdns library and is specifically designed to deal with managing dns. The only library that might be used with a non-BIND9 implementation is the liblwres library but that's the only one. We have pulled some of the libisc library into NTP because it's helpful in a number of areas. The libraries are pulled into building different binaries, named, dig, dnssec-keygen, etc. as needed. It would be a really bad idea to merge everything in one library. I really don't expect the libraries to be used outside of BIND9 with the possible exception of libisc and liblwres. What would you expect to use them for? The library that is usually used for linking with external applications is libbind and that has now been packaged separately. BTW, this question really belongs in bind-workers rather than bind-users. Danny _______________________________________________ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
