Re: [PATCH bpf-next 1/6] bpf: introduce BPF_PROG_TYPE_FILE_FILTER

[Roman Gushchin <guro@fb.com>]

On Wed, Oct 03, 2018 at 07:57:45PM -0700, Alexei Starovoitov wrote:
> Similar to networking sandboxing programs and cgroup-v2 based hooks
> (BPF_CGROUP_INET_[INGRESS|EGRESS,] BPF_CGROUP_INET[4|6]_[BIND|CONNECT], etc)
> introduce basic per-container sandboxing for file access via
> new BPF_PROG_TYPE_FILE_FILTER program type that attaches after
> security_file_open() LSM hook and works as additional file_open filter.
> The new cgroup bpf hook is called BPF_CGROUP_FILE_OPEN.
> 
> Just like other cgroup-bpf programs new BPF_PROG_TYPE_FILE_FILTER type
> is only available to root.
> 
> This program type has access to single argument 'struct bpf_file_info'
> that contains standard sys_stat fields:
> struct bpf_file_info {
>         __u64 inode;
>         __u32 dev_major;
>         __u32 dev_minor;
>         __u32 fs_magic;
>         __u32 mnt_id;
>         __u32 nlink;
>         __u32 mode;     /* file mode S_ISDIR, S_ISLNK, 0755, etc */
>         __u32 flags;    /* open flags O_RDWR, O_CREAT, etc */
> };

It's probably nice to have file uid/gid as well.

Thanks!