Re: [PATCH 00/11] TProxy for IPv6

[Amos Jeffries <squid3@treenet.co.nz>]

Jan Engelhardt wrote:
> On Friday 2009-09-04 08:07, Amos Jeffries wrote:
>>> Also, I have written a Python test script to test TProxy functionality
>>> automatically both for IPv4 and IPv6, I can post that as well if anyone is
>>> interested.
>> I'm interested :)
>>
>> Now that you have done this I'm going to have to find a robust userland
>> run-time test to see if the underlying TPROXY is v4-only or v6-enabled. If
>> anyone has suggestions they would be welcome.
> 
> Would this perhaps suffice?
> 
> assert(socket(PF_INET6, ...) >= 0);
> assert(setsockopt(fd, SOL_IP, IP_TRANSPARENT, ...) == 0);
> assert(bind(fd, {::2}) == 0);
> 
> At least something like that I remember to have used to determine
> tproxy-2.x ipv4 availability in the days. (I.e. seeing if setsockopt
> failed.)

Thanks Jan. I gave a variant that a try. It does seem to detect the 
feature support nicely.

However, trying to bind the real IP:port soon after results in "(98) 
Address already in use" even with a shutdown(tmp_sock,...) added to 
clean up after the test.

AYJ