On Mon, Oct 07, 2024 at 05:35:37PM +0100, Daniel P. Berrangé wrote: > See 'man 7 unix': > > [quote] > At least one byte of real data should be sent when > sending ancillary data. On Linux, this is required to > successfully send ancillary data over a UNIX domain > stream socket. When sending ancillary data over a > UNIX domain datagram socket, it is not necessary on > Linux to send any accompanying real data. However, > portable applications should also include at least one > byte of real data when sending ancillary data over a > datagram socket. > [/quote] > > So if your protocol doesn't already have a convenient bit of real data to > attach the SCM_RIGHTS data to, it is common practice to send a single dummy > data byte that is discarded.
Ah OK, thanks. Then maybe we can still consider dropping the initial four bytes for fd migrations; I left the other comment in the next patch. -- Peter Xu
