Compatibility Libpcap/Winpcap and timout of pcap_next_ex().

[Benoit <benpaka.spam () gmail com>]

Hello,

I've start a simple protocol to communicate with FPGA using only MAC layer.
This software should run under linux and windows, however i've a problem
with the timeout of pcap_next_ex() function under linux.

With winpcap when a packet is not coming the pcap_next_ex() return 0 but in
linux this function continue looping, and never return if no packet are
coming. Moreover sometimes I need to loop 10 times to be sure to receive
correctly the packet, .

The library used is the one in ubuntu 8.10:
libpcap0.8, libpcap0.8-dev, libpcap0.8-dbg (Version 0.9.8-5)

Here you have a sample of my code:

//Opening interface
    timeout=10;
    adhandle = pcap_open_live(ifname,    // name of the device
            SIZEIB_MTU,                        // portion of the packet to
capture
            FALSE,                            // promiscuous mode
            timeout,                // read timeout
            (char*)errbuf            // error buffer
    );


//Setting filter
if(pcap_compile(adhandle,&(fp),(char*)filter,0,netp) == -1) {
        fprintf(stderr,"Error calling pcap_compile\n");
        return EXIT_FAILURE;
 }
if(pcap_setfilter(adhandle,&(fp)) == -1) {
        fprintf(stderr,"Error setting filter\n");
        return EXIT_FAILURE;
}


//Send a packet
pcap_sendpacket(adhandle,(const u_char*)buff, SIZEIB_HDR_PKT+size_inB);


//Loop 10 times on pcap_next_ex() to receive at least 1 packet.
for(i=0;i<10;i++) {
ret=pcap_next_ex(adhandle, &(header), (const u_char**)(&p_buff));
if(ret>0) {
        nofB=ifhard->header->len;
        memcpy(buff,p_buff,nofB);
        break;
}
}

Can you help me to make the timeout of pcap_next_ex() works under linux?

Thanks



--
Benoit RAT
www.neub.co.nr
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