Re: How to set my device name with pcap_platform_finddevs()

[Guy Harris <guy () alum mit edu>]

On Sep 25, 2007, at 4:33 AM, Varuna De Silva wrote:

> 1. How should I work around so that pcap_findalldevs() will add my  
> device in
> the list?

If you're doing this on Windows, you will have to:

        modify pcap_findalldevs() in fad-win32.c to, right before it does

                if (ret == -1) {
                        /*
                         * We had an error; free the list we've been constructing.
                         */
                        if (devlist != NULL) {
                                pcap_freealldevs(devlist);
                                devlist = NULL;
                        }
                }
        do

                if (ret != -1) {
                        /*
                         * We haven't had any errors yet; do any platform-specific
                         * operations to add devices.
                         */
                        if (pcap_platform_finddevs(&devlist, errbuf) < 0)
                                ret = -1;
                }

Then add a routine to your pcap-xxx.c that, similarly to  
septel_platform_finddevs(), adds your device to the list of devices,  
and then add a routine to pcap-win32.c called  
"pcap_platform_finddevs()" that calls your routine, similarly to the  
Linux pcap_platform_finddevs() in pcap-linux.c.

If you're doing this on some form of UN*X, e.g. Linux, just add the  
routine to your pcap-xxx.c and find the appropriate pcap-yyy.c and  
modify its pcap_platform_finddevs() to call your routine.

> 2. What is the relationship between pcap_platform_finddevs() and
> pcap_findalldevs() function
>   in this regard ?

pcap_findalldevs() is the routine that finds "standard" network  
adapters (i.e., the ones that the OS's mechanism for enumerating  
network adapters finds); pcap_platform_finddevs() is the routine that  
finds other adapters for a particular platform.

> 3. How should I modify "pcap_platform_finddevs()" so that I get my  
> device
> added?

See septel_platform_finddevs() for an example.

> do I need to do this?

Yes.

> 4. Where are these two functions written, (pcap_findalldevs() I  
> found only
> in fad32! Sorry
> for this foolish question, But I was not able to figure it out)

They're in libpcap, but not in the current version of WinPcap, because  
pcap-win32.c and fad-win32.c didn't have them.  I've just checked  
changes to pcap-win32.c and fad-win32.c into the main branch of  
libpcap to add those routines; hopefully they'll appear in a future  
version of WinPcap.
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