Marcus Wichelmann wrote: > The open_tuntap helper function uses open() to get a file descriptor for > /dev/net/tun. > > The open(2) manpage writes this about its return value: > > On success, open(), openat(), and creat() return the new file > descriptor (a nonnegative integer). On error, -1 is returned and > errno is set to indicate the error. > > This means that the fd > 0 assertion in the open_tuntap helper is > incorrect and should rather check for fd >= 0. > > When running the BPF selftests locally, this incorrect assertion was not > an issue, but the BPF kernel-patches CI failed because of this: > > open_tuntap:FAIL:open(/dev/net/tun) unexpected open(/dev/net/tun): > actual 0 <= expected 0 > > Signed-off-by: Marcus Wichelmann <marcus.wichelmann@xxxxxxxxxxxxxxxx> Reviewed-by: Willem de Bruijn <willemb@xxxxxxxxxx>
