libpcap "_pcap_version"

[VagelisD]

Hello, i have a problem compiling tcptraceroute, although there is a libpcap on my system, i dont get what is going wrong at the compilation process.

gcc -g -O2 -Wall -o tcptraceroute main.o datalink.o util.o probe.o capture.o -lnet -lpcap Undefined symbols for architecture x86_64: "_pcap_version", referenced from: _main in main.o ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation) make: *** [tcptraceroute] Error 1

And also with homebrew after successful installation and "sudo tcptraceroute"

dyld: Symbol not found: _pcap_version Referenced from: /usr/local/bin/tcptraceroute Expected in: /usr/lib/libpcap.A.dylib in /usr/local/bin/tcptraceroute Abort trap: 6

Im on macOS Sierra 10.12.4 version

[VagelisD]

Problem solved with ./configure --with-libpcap=/usr/local/Cellar/libpcap/1.8.1/

Even though i symlinked libpcap from homebrew with brew link libpcap it didn't make any difference, it went ahead compiling with libpcap installed from Xcode

I guess tcptraceroute doesn't like the libpcap version from Xcode, is there any way installing tcptraceroute from homebrew and providing libpcap this way? thanks in advance

[ghost]

Seems tcpreplay folks found a similar problem and solved it if anyone wants to check it out the link is below.
tcpreplay Issue #353

[VagelisD]

@begsthehessian thanks, i also checked the pcap_ver with nm like he did, same version, same problem

nm /usr/lib/libpcap.A.dylib | grep pcap_ver
0000000000025df0 s _pcap_version_string

[sarim]

Same problem for me in 10.12.4. For now i just added

 inreplace "capture.h", "extern char pcap_version[]", "char *pcap_version"

in homebrew to make it run.
Seems like pcap_version is not used anywhere other than logging pcap version in debug, so its not really needed for regular usage.

[mct]

Thanks for the catch!

Googling around a little, it looks like we shouldn't be using the symbol pcap_version directly, but rather calling the exported function pcap_lib_version() to access the version string.

[sarim]

(y)

Also is there any reason to define it in capture.h? maybe just a use a local variable in main.c inside the function where the debug is logged.