LinuxQuestions.org - Libnet Seg. Fault calling libnet_pblock_new() from libnet_build

Solved previous problem i got another one.
In building a TCP packet through libnet function libnet_build_tcp() i got a SIGSEV in calling of libnet_pblock_new() function.

This is what libnet shows:

Code:

#0  0x00007ffff7bd0bf9 in libnet_pblock_new () from /usr/lib64/libnet.so.1

No symbol table info available.

#1  0x00007ffff7bcda52 in libnet_build_tcp () from /usr/lib64/libnet.so.1

No symbol table info available.

#2  0x000000000040172c in caught_packet (user_args=0x7fffffffe458 "\020\060`", 

    cap_header=0x7fffffffe3a0, packet=0x7ffff73d4046 "") at rst_hijack.c:86

        libnet_ctx = 0x7fffffffe458

        bcount = 0

        IPhdr = 0x7ffff73d4054

        TCPhdr = 0x7ffff73d4068

        source_ip = 1008806360678825902

        dest_ip = 9214452798765137930

and the SIGSEV:

Code:

Program received signal SIGSEGV, Segmentation fault.

0x00007ffff7bd0bf9 in libnet_pblock_new () from /usr/lib64/libnet.so.1

My code:

Code:

        libnet_build_tcp(htons(TCPhdr->th_dport),//Source port

                                htons(TCPhdr->th_sport),//Destination port

                                htonl(TCPhdr->th_ack),//SEQ

                                htonl(libnet_get_prand(LIBNET_PRu32)),//Ack

                                TH_RST,//control flags

                                libnet_get_prand(LIBNET_PRu16),//Win Size

                                0,//Sum

                                0,//Urgent pointer

                                LIBNET_TCP_H,//tcp len

                                NULL,//Payload

                                0,//Payload length

                                libnet_ctx,//Libnet Context

                                0//Ptag IPv4 Header

                                );

TCPhdr is a struct which contains a TCP header, libnet_ctx is a libnet context .

What's wrong with it ?