On Wed, Aug 26, 2020 at 08:57:17AM -0500, Denis Kenzior wrote: > > I'm just waking up now, so I might seem dense, but for my education, can you > tell me why we need to set MSG_MORE when we issue just a single sendmsg > followed immediately by recv/recvmsg? ell/iwd operates on small buffers, so > we don't really feed the kernel data in multiple send operations. You can > see this in the ell git tree link referenced in Andrew's reply. You obviously don't need MSG_MORE if you're doing a single sendmsg. The problematic code is in l_cipher_set_iv. It does a sendmsg(2) that expects to be followed by more sendmsg(2) calls before a recvmsg(2). That's the one that needs a MSG_MORE.