Em Fri, Feb 01, 2008 at 05:42:23PM -0800, Rick Jones escreveu: > Hi - > > I'm tweaking the netperf omni tests to be able to run over DCCP. I've run > across a not-unorecedented problem with getaddrinfo() not groking either > SOCK_DCCP or IPPROTO_DCCP in the hints, and that I can more or less live > with - I had to do a kludge for getaddrinfo() for IPPROTO_SCTP under Linux > at one point and I can see how the two are not necessarily going to be in > sync.
See the ttcp patch where we do a xgetaddrinfo crude hack to handle dccp: http://vger.kernel.org/~acme/dccp/ttcp.c > And I've worked-around no user-level include files (ie without setting > __KERNEL__) define the DCCP stuff, and that is OK too, albeit somewhat > inconvenient. Humm, for what? Again, see the ttcp code above: > My question though is why on earth does an SO_REUSEADDR setsockopt() > against a DCCP socket have to be SOL_DCCP? SCTP and TCP are quite happy > with SOL_SOCKET, and it might be foolish consistency, but since the option > _does_ begin with SO_ I'd have expected it to work for SOL_SOCKET, but > (again RHEL5.1, yes, I do plan on getting upstream but have to satisfy > several masters) it doesn't seem to be the case - a subsequent listen() or > connect() call after an SOL_SOCKET SO_REUSEADDR against a DCCP socket > leaves one SOL as it were... Strange, lemme check... 1. sys_socketcall -> 2. sys_setsockopt -> 3. if (level == SOL_SOCKET) { 4. sock_setsockopt: 5. case SO_REUSEADDR: 6. sk->sk_reuse = valbool; 7. } else 8. sock->ops->setsockopt = inet_dccp_ops->setsockopt = 9. inet_dccp_ops->setsockopt = sock_common_setsockopt -> 10. sk->sk_prot->setsockopt = dccp_v4_prot->setsockopt = 11. dccp_setsockopt 12. if (level != SOL_DCCP) 13. return inet_csk(sk)->icsk_af_ops->setsockopt() = 14. ip_setsockopt 15. return do_dccp_setsockopt() SO_REUSEADDR is handled in 4, if you pass SOL_SOCKET. If instead you pass SOL_DCCP we'll go down the rabbit hole till do_dccp_setsockopt() and SO_REUSEADDR, that is equal to 2, will be interpreted as DCCP_SOCKOPT_SERVICE, that is also equal to 2, so you'll be setting the service, not changing the SO_REUSEADDR setting. The problem here is that you need to use: setsockopt(fd, SOL_DCCP, DCCP_SOCKOPT_PACKET_SIZE, service, sizeof(service)); Again, take a look at the ttcp patch, the other patches for iperf, netcat, etc handles this. > Of course the setsockopt(SO_REUSEADDR) against the DCCP socket using > SOL_SOCKET itself doesn't fail, only the later listen() or connect() > call... > > happy benchmarking, Look forward for a happy DCCP netperf bencharking session! Thanks a lot, - Arnaldo -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
