On Fri, 1 Apr 2016 00:28:57 +0200 Guus Sliepen <g...@tinc-vpn.org> wrote:
> On Thu, Mar 31, 2016 at 05:20:50PM -0400, David Miller wrote: > > > >> I'm trying to reduce system call overhead when reading/writing to/from a > > >> tun device in userspace. [...] What would be the right way to do this? > > >> > > > Personally I think tun could benefit greatly if it were implemented as > > > a socket instead of character interface. One thing that could be much > > > better is sending/receiving of meta data attached to skbuf. For > > > instance GSO data could be in ancillary data in a socket instead of > > > inline with packet data as tun seems to be doing now. > > > > Agreed. > > Ok. So how should the userspace API work? Creating an AF_PACKET socket > and then using a tun ioctl to create a tun interface and bind it to the > socket? > > int fd = socket(AF_PACKET, ...) > struct ifreq ifr = {...}; > ioctl(fd, TUNSETIFF, &ifr); > Rather than bodge AF_PACKET onto TUN, why not just create a new device type and control it from something modern like netlink.