.so dynamic library mangling tool

[Peter L. Peres]

On Sun, 5 Dec 2004, Steve Harvey wrote:

> On Sat, Dec 04, 2004 at 10:12:46PM -0500, Sergey Kuznetsov wrote:
>> The issue was not the library itself ( the library at the right place,
>> at /lib directory )
>> but with the .so file itself.
>> that file is a optional part of the Asterisk PBX program, and it's G.729
>> codec library,
>> and specifically for GLIB 2.3 X86_64 platform under Gentoo.
>> The error Asterisk gives me is:
>>
>> [codec_g729a.so]Dec  4 19:34:04 WARNING[16384]: loader.c:248
>> ast_load_resource: /usr/lib/asterisk/modules/codec_g729a.so: undefined
>> symbol: gzread
>> Dec  4 19:34:04 WARNING[16384]: loader.c:429 load_modules: Loading
>> module codec_g729a.so failed!
>>
>> The ldd saying about codec_g729a.so is:
>> # ldd codec_g729a.so
>>        libc.so.6 => /lib/libc.so.6 (0x0000002a9567d000)
>>        /lib64/ld-linux-x86-64.so.2 => /lib64/ld-linux-x86-64.so.2
>> (0x000000552aaaa000)
>>
>> The nm -D codec_g729a.so saying is:
>>                 U gzclose
>>                 U gzdopen
>>                 U gzread
>>
>> The nm -D /lib/libz.so saying is:
>> 00000000000035f0 T gzclose
>> 00000000000026a0 T gzdopen
>> 0000000000002ab0 T gzread
>>
>> The objdump -x codec_g729a.so saying is:
>> Dynamic Section:
>>  NEEDED      libc.so.6
>>  INIT        0x35c0
>>
>> As you can see here is the NEEDED libz.so is absent. And this is I am
>> trying to fix. Thats why I need such tool who can mangle the any
>> library's header I want.
>>
>  I assume that setting the LD_PRELOAD environment variable is not an
> option in your situation.
>
>  I don't know of any single tool that will do that.  Perhaps you might
> be able to carve the library up with objcopy and re-build it using ld
> and a specially crafted linker script in order to get both NEEDED
> entries.
>
>  If you have write perms on /usr/local/lib, I might try building a
> customized libc to which the libz modules have been added, making it
> reachable via /usr/local/lib/libZ.so.6 (making sure that libZ is unique
> in your system).  Ensure that its internal SONAME is "libZ.so.6" (vi
> makes a good binary editor), run ldconfig, then use a patched
> codec_g729a.so with the "libc.so.6" string in the file suitably altered.

ld -shared -fpic -soname=libZ.so.6 ... -o /lib/hacked/libc.so.6 would work 
great imho.

ld can concatenate as many libraries as you need.

Peter
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