Re: [PATCH v3 net-next 0/2] bpfilter

From: Greg KH
Date: Wed May 23 2018 - 12:41:07 EST


On Wed, May 23, 2018 at 01:26:48PM -0400, David Miller wrote:
> From: Alexei Starovoitov <ast@xxxxxxxxxx>
> Date: Mon, 21 May 2018 19:22:28 -0700
>
> > v2->v3:
> > - followed Luis's suggestion and significantly simplied first patch
> > with shmem_kernel_file_setup+kernel_write. Added kdoc for new helper
> > - fixed typos and race to access pipes with mutex
> > - tested with bpfilter being 'builtin'. CONFIG_BPFILTER_UMH=y|m both work.
> > Interesting to see a usermode executable being embedded inside vmlinux.
> > - it doesn't hurt to enable bpfilter in .config.
> > ip_setsockopt commands sent to usermode via pipes and -ENOPROTOOPT is
> > returned from userspace, so kernel falls back to original iptables code
> >
> > v1->v2:
> > this patch set is almost a full rewrite of the earlier umh modules approach
> > The v1 of patches and follow up discussion was covered by LWN:
> > https://lwn.net/Articles/749108/
> >
> > I believe the v2 addresses all issues brought up by Andy and others.
> > Mainly there are zero changes to kernel/module.c
> > Instead of teaching module loading logic to recognize special
> > umh module, let normal kernel modules execute part of its own
> > .init.rodata as a new user space process (Andy's idea)
> > Patch 1 introduces this new helper:
> > int fork_usermode_blob(void *data, size_t len, struct umh_info *info);
> > Input:
> > data + len == executable file
> > Output:
> > struct umh_info {
> > struct file *pipe_to_umh;
> > struct file *pipe_from_umh;
> > pid_t pid;
> > };
>
> Series applied, let the madness begin... :-)

Yeah, this is going to be fun :)