On Wed, 6 Dec 2023 15:59:40 +0100 Stefano Brivio <sbrivio(a)redhat.com> wrote:[...] but on a kernel with your patch, I get ENOTCONN on recvmsg(). If I replace that by a simple recv(): sendto(5, "ab", 2, 0, NULL, 0) = 2 recvfrom(6, "ab", 10, 0, NULL, NULL) = 2 ...so I don't think it's a fundamental issue with this approach, rather something with your patch, but I'm not yet sure what. :)Oops, my bad, I got the order of fields in struct msghdr wrong. New version attached, this one works. -- Stefano