mptcp

[Li-Yijun-lyj]

I'd like to ask how iperf3 tests mptcp. I tried to directly add the -m parameter after iperf3 [-s|-c host], but failed.

[davidBar-On]

iperf3 confugure checks whether IPPROTO_MPTCP is defined in <netinet/in.h>, and sets HAVE_IPPROTO_MPTCP accordingly. iperf3 then use it to set MPTCP protocol. E.g. in the listener side

iperf/src/iperf_tcp.c

Lines 224 to 233 in 9f6dc21

	#if defined(HAVE_IPPROTO_MPTCP)
	if (test->mptcp)
	proto = IPPROTO_MPTCP;
	#endif
	if ((s = socket(res->ai_family, SOCK_STREAM, proto)) < 0) {
	freeaddrinfo(res);
	i_errno = IESTREAMLISTEN;
	return -1;
	}

The problem seems to be that configure should also check whether MPCTP is really supported, by checking whether /proc/sys/net/mptcp folder is available, or even if /proc/sys/net/mptcp/enabled file is available (and maybe also if its value is "1").

I don't have MPCTP, so I can't check what is sufficient for determining that it is supported.

[Li-Yijun-lyj]

Thank you for your response.