Re: On Yaks and the Shaving Thereof - finding exported symbols of a C library

in reply to On Yaks and the Shaving Thereof - finding exported symbols of a C library

UPDATE: I hate answering my own questions on here, but after playing with this all morning with no luck, a posted question and then lunch; I returned with a new direction and found this:

http://sourceforge.net/projects/mingw-w64/forums/forum/723797/topic/3882579

Luckily, I had a copy of gendef.exe from a MinGW-64 (4.4.5) that I have installed as gendef.exe doesn't seem to be in c:\strawberry\c\bin. dlltool is included with Strawberry, so:

NOTE: pexports.exe is included with Strawberry and the output is the same as gendef.exe, so one could just use pexports.exe instead of gendef.exe.

NOTE: There is a wpcap.dll installed in C:\Windows\system32 and C:\Windows\SysWOW64. I used the latter.

VinsWorldcom@C:\Users\VinsWorldcom\tmp> cp c:\Windows\SysWOW64\wpcap.d
+ll .

VinsWorldcom@C:\Users\VinsWorldcom\tmp> \Min\MinGW-64\bin\gendef.exe w
+pcap.dll
 * [wpcap.dll] Found PE image

VinsWorldcom@C:\Users\VinsWorldcom\tmp> which dlltool
C:\strawberry\c\bin\dlltool.exe

VinsWorldcom@C:\Users\VinsWorldcom\tmp> dlltool --as-flags=--64 -m i38
+6:x86-64 -k --output-lib libwpcap.a --input-def wpcap.def

VinsWorldcom@C:\Users\VinsWorldcom\tmp> ls -al libwpcap.a

 Directory of C:\Users\VinsWorldcom\tmp

03/29/2011  02:27 PM            65,656 libwpcap.a
               1 File(s)         65,656 bytes

VinsWorldcom@C:\Users\VinsWorldcom\tmp> ls -al WpdPack\Lib\libwpcap.a

 Directory of C:\Users\VinsWorldcom\tmp\WpdPack\Lib

06/25/2010  10:02 AM            54,276 libwpcap.a
               1 File(s)         54,276 bytes

VinsWorldcom@C:\Users\VinsWorldcom\tmp> ls -al WpdPack\Lib\x64\libwpca
+p.a
File Not Found

 Directory of C:\Users\VinsWorldcom\tmp\WpdPack\Lib\x64


VinsWorldcom@C:\Users\VinsWorldcom\tmp> cp libwpcap.a WpdPack\Lib\x64
[download]

I used gendef.exe and dlltool.exe to create a new libwpcap.a static library from the 64-bit wpcap.dll. Why isn't there one included in the WpdPack/Lib/x64 directory already - who knows? In any case, once the new static library was copied into place, I re-ran 'perl Makefile.PL' with the following adjustment:

perl Makefile.PL INC=-IC:/Users/VinsWorldcom/tmp/WpdPack/Include "LIBS
+=-LC:/Users/VinsWorldcom/tmp/WpdPack/Lib/x64 -lwpcap"
[download]

The subsequent 'dmake' worked this time, 'dmake test' had a few failures (similar to my WinXP experience). After a 'dmake install' a quick test script works fine:

VinsWorldcom@C:\Users\VinsWorldcom\tmp> more test.pl
use Net::Pcap qw(:functions);

@devs = pcap_findalldevs(\%devinfo, \$err);
for my $dev (@devs) {
    print "$dev : $devinfo{$dev}\n"
}

VinsWorldcom@C:\Users\VinsWorldcom\tmp> perl test.pl
\Device\NPF_{7C974F8C-6E64-44D9-B5F5-BE1242FA897D} : Intel(R) PRO/1000
+ MT Network Connection

VinsWorldcom@C:\Users\VinsWorldcom\tmp>
[download]

If this node goes completely unnoticed, it will at least serve as a personal archive for the next time I'm doing this on Win7.

ORIGINAL POST

So the patches worked for me with WinXP (x86, SP3) / Strawberry (5.12.2). However, I'm also trying this on Windows 7 (64-bit) / Strawberry (5.12.2 MSWin32-x64-multi-thread) and it's not going as well.

VinsWorldcom@C:\strawberry\cpan\build\Net-Pcap-0.16-BzfeHy# perl Makef
+ile.PL INC=-IC:/Users/VinsWorldcom/tmp/WpdPack/Include "LIBS=-LC:/Use
+rs/VinsWorldcom/tmp/WpdPack/Lib -lwpcap"
socket.h patched... ok
looking for -lwpcap... yes
checking for pcap_lib_version() in -lwpcap... yes
Using 'C:\Windows\system32\wpcap.dll' as potential symbol candidate at
+ Makefile.PL line 556.
detecting available functions... ok
Using 'C:\Windows\system32\wpcap.dll' as potential symbol candidate at
+ Makefile.PL line 556.
detecting available functions... ok
Writing Makefile for Net::Pcap

VinsWorldcom@C:\strawberry\cpan\build\Net-Pcap-0.16-BzfeHy# dmake
Skip blib\lib\Net\Pcap.pm (unchanged)
gcc -c  -IC:/Users/VinsWorldcom/tmp/WpdPack/Include  -s -O2 -DWIN32 -D
+HAVE_DES_FCRYPT -DWIN64 -DCONSERVATIVE -DUSE_SITECUSTOMIZE -DPERL_IMP
+LICIT_CONTEXT -DPERL_IMPLICIT_SYS -fno-strict-aliasing -mms-bitfields
+ -DPERL_MSVCRT_READFIX -s -O2  -DVERSION=\"0.16\"    -DXS_VERSION=\"0
+.16\"  "-IC:\strawberry\perl\lib\CORE"-DWINSOCK2_H_REQUESTED -DWPCAP 
+-DHAVE_REMOTE -DHAVE_BLANK -DHAVE_PCAP_LIB_VERSION -DHAVE_PCAP_BREAKL
+OOP -DHAVE_PCAP_COMPILE_NOPCAP -DHAVE_PCAP_CREATESRCSTR -DHAVE_PCAP_D
+ATALINK_NAME_TO_VAL -DHAVE_PCAP_DATALINK_VAL_TO_DESCRIPTION -DHAVE_PC
+AP_DATALINK_VAL_TO_NAME -DHAVE_PCAP_DUMP_FILE -DHAVE_PCAP_DUMP_FLUSH 
+-DHAVE_PCAP_FINDALLDEVS -DHAVE_PCAP_GETEVENT -DHAVE_PCAP_GETNONBLOCK 
+-DHAVE_PCAP_LIB_VERSION-DHAVE_PCAP_NEXT_EX -DHAVE_PCAP_OPEN -DHAVE_PC
+AP_OPEN_DEAD -DHAVE_PCAP_PARSESRCSTR -DHAVE_PCAP_SENDPACKET -DHAVE_PC
+AP_SENDQUEUE_ALLOC -DHAVE_PCAP_SENDQUEUE_QUEUE -DHAVE_PCAP_SENDQUEUE_
+TRANSMIT -DHAVE_PCAP_SETBUFF -DHAVE_PCAP_SETMINTOCOPY -DHAVE_PCAP_SET
+MODE -DHAVE_PCAP_SETNONBLOCK -DHAVE_PCAP_SET_DATALINK Pcap.c
In file included from Pcap.xs:43:
stubs.inc:187:2: warning: #warning "the function pcap_list_datalinks()
+ is not available"
stubs.inc:277:2: warning: #warning "the function pcap_get_selectable_f
+d() is not available"
stubs.inc:388:2: warning: #warning "the function pcap_setuserbuffer() 
+is not available"
stubs.inc:455:2: warning: #warning "the function pcap_sendqueue_destro
+y() is not available"
stubs.inc:514:2: warning: #warning "the function pcap_setsampling() is
+ not available"
Pcap.c: In function 'XS_Net__Pcap_strerror':
Pcap.c:1584: warning: assignment discards qualifiers from pointer targ
+et type
Pcap.xs: In function 'XS_Net__Pcap_getevent':
Pcap.xs:951: warning: cast from pointer to integer of different size
Running Mkbootstrap for Net::Pcap ()
C:\strawberry\perl\bin\perl.exe -MExtUtils::Command -e "chmod" -- 644 
+Pcap.bs
dlltool --def Pcap.def --output-exp dll.exp
g++ -o blib\arch\auto\Net\Pcap\Pcap.dll -Wl,--base-file -Wl,dll.base -
+mdll -s -L"C:\strawberry\perl\lib\CORE" -L"C:\strawberry\c\lib" Pcap.
+o -Wl,--image-base,0x7e070000  C:\strawberry\perl\lib\CORE\libperl512
+.a C:\Users\VinsWorldcom\tmp\WpdPack\Lib\libwpcap.a C:\strawberry\c\x
+86_64-w64-mingw32\lib\libmoldname.a C:\strawberry\c\x86_64-w64-mingw3
+2\lib\libkernel32.a C:\strawberry\c\x86_64-w64-mingw32\lib\libuser32.
+a C:\strawberry\c\x86_64-w64-mingw32\lib\libgdi32.a C:\strawberry\c\x
+86_64-w64-mingw32\lib\libwinspool.a C:\strawberry\c\x86_64-w64-mingw3
+2\lib\libcomdlg32.a C:\strawberry\c\x86_64-w64-mingw32\lib\libadvapi3
+2.a C:\strawberry\c\x86_64-w64-mingw32\lib\libshell32.a C:\strawberry
+\c\x86_64-w64-mingw32\lib\libole32.a C:\strawberry\c\x86_64-w64-mingw
+32\lib\liboleaut32.a C:\strawberry\c\x86_64-w64-mingw32\lib\libnetapi
+32.a C:\strawberry\c\x86_64-w64-mingw32\lib\libuuid.a C:\strawberry\c
+\x86_64-w64-mingw32\lib\libws2_32.a C:\strawberry\c\x86_64-w64-mingw3
+2\lib\libmpr.a C:\strawberry\c\x86_64-w64-mingw32\lib\libwinmm.a C:\s
+trawberry\c\x86_64-w64-mingw32\lib\libversion.a C:\strawberry\c\x86_6
+4-w64-mingw32\lib\libodbc32.a C:\strawberry\c\x86_64-w64-mingw32\lib\
+libodbccp32.a C:\strawberry\c\x86_64-w64-mingw32\lib\libcomctl32.a dl
+l.exp
Pcap.o:Pcap.c:(.text+0x126b): undefined reference to `pcap_sendqueue_t
+ransmit'
Pcap.o:Pcap.c:(.text+0x16a7): undefined reference to `pcap_sendqueue_q
+ueue'
Pcap.o:Pcap.c:(.text+0x1924): undefined reference to `pcap_sendqueue_a
+lloc'
Pcap.o:Pcap.c:(.text+0x1b31): undefined reference to `pcap_sendpacket'
Pcap.o:Pcap.c:(.text+0x1d20): undefined reference to `pcap_getevent'
Pcap.o:Pcap.c:(.text+0x1f6a): undefined reference to `pcap_setmintocop
+y'
Pcap.o:Pcap.c:(.text+0x21ea): undefined reference to `pcap_setmode'
Pcap.o:Pcap.c:(.text+0x246a): undefined reference to `pcap_setbuff'
Pcap.o:Pcap.c:(.text+0x27aa): undefined reference to `pcap_open'
Pcap.o:Pcap.c:(.text+0x2eb9): undefined reference to `pcap_parsesrcstr
+'
Pcap.o:Pcap.c:(.text+0x3605): undefined reference to `pcap_createsrcst
+r'
Pcap.o:Pcap.c:(.text+0x38c8): undefined reference to `pcap_geterr'
Pcap.o:Pcap.c:(.text+0x3b14): undefined reference to `pcap_geterr'
Pcap.o:Pcap.c:(.text+0x3b24): undefined reference to `pcap_stats'
Pcap.o:Pcap.c:(.text+0x3e28): undefined reference to `pcap_fileno'
Pcap.o:Pcap.c:(.text+0x4020): undefined reference to `pcap_file'
Pcap.o:Pcap.c:(.text+0x4254): undefined reference to `pcap_lib_version
+'
Pcap.o:Pcap.c:(.text+0x4420): undefined reference to `pcap_strerror'
Pcap.o:Pcap.c:(.text+0x461c): undefined reference to `pcap_perror'
Pcap.o:Pcap.c:(.text+0x47c8): undefined reference to `pcap_minor_versi
+on'
Pcap.o:Pcap.c:(.text+0x49d8): undefined reference to `pcap_major_versi
+on'
Pcap.o:Pcap.c:(.text+0x4be8): undefined reference to `pcap_is_swapped'
Pcap.o:Pcap.c:(.text+0x4df8): undefined reference to `pcap_snapshot'
Pcap.o:Pcap.c:(.text+0x5000): undefined reference to `pcap_datalink_va
+l_to_description'
Pcap.o:Pcap.c:(.text+0x51c0): undefined reference to `pcap_datalink_va
+l_to_name'
Pcap.o:Pcap.c:(.text+0x5385): undefined reference to `pcap_datalink_na
+me_to_val'
Pcap.o:Pcap.c:(.text+0x55ba): undefined reference to `pcap_set_datalin
+k'
Pcap.o:Pcap.c:(.text+0x57c8): undefined reference to `pcap_datalink'
Pcap.o:Pcap.c:(.text+0x59d8): undefined reference to `pcap_dump_flush'
Pcap.o:Pcap.c:(.text+0x5bd0): undefined reference to `pcap_dump_file'
Pcap.o:Pcap.c:(.text+0x5e63): undefined reference to `pcap_dump_close'
Pcap.o:Pcap.c:(.text+0x5fd3): undefined reference to `pcap_close'
Pcap.o:Pcap.c:(.text+0x6143): undefined reference to `pcap_breakloop'
Pcap.o:Pcap.c:(.text+0x62b3): undefined reference to `pcap_freecode'
Pcap.o:Pcap.c:(.text+0x64cf): undefined reference to `pcap_setfilter'
Pcap.o:Pcap.c:(.text+0x6861): undefined reference to `pcap_compile_nop
+cap'
Pcap.o:Pcap.c:(.text+0x6ccd): undefined reference to `pcap_geterr'
Pcap.o:Pcap.c:(.text+0x6ce8): undefined reference to `pcap_compile'
Pcap.o:Pcap.c:(.text+0x71d1): undefined reference to `pcap_dump'
Pcap.o:Pcap.c:(.text+0x751c): undefined reference to `pcap_next_ex'
Pcap.o:Pcap.c:(.text+0x79c2): undefined reference to `pcap_next'
Pcap.o:Pcap.c:(.text+0x7e59): undefined reference to `pcap_loop'
Pcap.o:Pcap.c:(.text+0x81ec): undefined reference to `pcap_geterr'
Pcap.o:Pcap.c:(.text+0x8224): undefined reference to `pcap_dispatch'
Pcap.o:Pcap.c:(.text+0x8539): undefined reference to `pcap_getnonblock
+'
Pcap.o:Pcap.c:(.text+0x88b8): undefined reference to `pcap_setnonblock
+'
Pcap.o:Pcap.c:(.text+0x8bc8): undefined reference to `pcap_dump_open'
Pcap.o:Pcap.c:(.text+0x8db7): undefined reference to `pcap_open_offlin
+e'
Pcap.o:Pcap.c:(.text+0x9017): undefined reference to `pcap_open_dead'
Pcap.o:Pcap.c:(.text+0x92c5): undefined reference to `pcap_open_live'
Pcap.o:Pcap.c:(.text+0x95eb): undefined reference to `pcap_findalldevs
+'
Pcap.o:Pcap.c:(.text+0x97b2): undefined reference to `pcap_lookupdev'
Pcap.o:Pcap.c:(.text+0x988d): undefined reference to `pcap_freealldevs
+'
Pcap.o:Pcap.c:(.text+0x9b10): undefined reference to `pcap_lookupnet'
Pcap.o:Pcap.c:(.text+0x9eae): undefined reference to `pcap_lookupdev'
collect2: ld returned 1 exit status
dmake:  Error code 129, while making 'blib\arch\auto\Net\Pcap\Pcap.dll
+'

VinsWorldcom@C:\strawberry\cpan\build\Net-Pcap-0.16-BzfeHy#
[download]

The "undefined reference to `pcap_...'" usually show up because the functions have no library to link against - at least that's what I've seen before. However, I clearly tell it to link against wpcap (-lwpcap), where to find libwpcap.a (C:/Users/VinsWorldcom/tmp/WpdPack/Lib) and those directives show up in the 'dmake' output.

Could this be a 32-bit/64-bit issue - as this method worked fine on a WinXP (32-bit) system but is failing on Win7 (64-bit)?

I also noticed in the WpdPack/Lib subdirs, there is an x64 subdirectory, but there is only MSVC++ .lib files, no .a files.

VinsWorldcom@C:\Users\VinsWorldcom\tmp\WpdPack> ls -alR Lib

 Directory of C:\Users\VinsWorldcom\tmp\WpdPack\Lib

03/29/2011  01:43 PM    <DIR>          .
03/29/2011  01:43 PM    <DIR>          ..
06/25/2010  10:01 AM            20,814 libpacket.a
06/25/2010  10:02 AM            54,276 libwpcap.a
06/25/2010  09:47 AM             8,450 Packet.lib
06/25/2010  09:47 AM            19,320 wpcap.lib
03/29/2011  01:43 PM    <DIR>          x64
               4 File(s)        102,860 bytes

 Directory of C:\Users\VinsWorldcom\tmp\WpdPack\Lib\x64

03/29/2011  01:43 PM    <DIR>          .
03/29/2011  01:43 PM    <DIR>          ..
06/25/2010  09:49 AM             8,290 Packet.lib
06/25/2010  09:49 AM            18,892 wpcap.lib
               2 File(s)         27,182 bytes

     Total Files Listed:
               6 File(s)        130,042 bytes
[download]

Comment on Re: On Yaks and the Shaving Thereof - finding exported symbols of a C library Select or Download Code

Replies are listed 'Best First'.
Re^2: On Yaks and the Shaving Thereof - finding exported symbols of a C library by Corion (Patriarch) on Nov 09, 2016 at 21:11 UTC
Thanks again for posting these instructions, they helped me build Net::Pcap 0.18 on Windows 7 with Strawberry Perl 5.20 64bit. I've applied these changes to https://github.com/Corion/Net-Pcap and created a pull request as https://github.com/maddingue/Net-Pcap/pull/7. Some tests still fail for me with the changes above but I will investigate later.	[reply]
Re^2: On Yaks and the Shaving Thereof - finding exported symbols of a C library by sethlwilson (Initiate) on Jun 29, 2011 at 18:17 UTC
Thanks so much for posting this! I'd been stuck for days trying to figure out why Net:Pcap wouldn't build for me even with the patch. Your solution worked perfectly!	[reply]

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