[iproute2 net-next 0/8] Add support for vrf helper

[David Ahern <dsa@cumulusnetworks.com>]

This series adds support to iproute2 to run a command against a specific
VRF. The user semnatics are similar to 'ip netns'.

The 'ip vrf' subcommand supports 3 usages:

1. Run a command against a given vrf:
       ip vrf exec NAME CMD

   Uses the recently committed cgroup/sock BPF option. vrf directory
   is added to cgroup2 mount. Individual vrfs are created under it. BPF
   filter is attached to vrf/NAME cgroup2 to set sk_bound_dev_if to the
   device index of the VRF. From there the current process (ip's pid) is
   addded to the cgroups.proc file and the given command is exected. In
   doing so all AF_INET/AF_INET6 (ipv4/ipv6) sockets are automatically
   bound to the VRF domain.

   The association is inherited parent to child allowing the command to
   be a shell from which other commands are run relative to the VRF.

2. Show the VRF a process is bound to:
       ip vrf id
   This command essentially looks at /proc/pid/cgroup for a "::/vrf/"
   entry.

3. Show process ids bound to a VRF
       ip vrf pids NAME
   This command dumps the file MNT/vrf/NAME/cgroup.procs since that file
   shows the process ids in the particular vrf cgroup.

David Ahern (8):
  lib bpf: Add support for BPF_PROG_ATTACH and BPF_PROG_DETACH
  bpf: export bpf_prog_load
  Add libbpf.h header with BPF_XXXX macros
  move cmd_exec to lib utils
  Add filesystem APIs to lib
  change name_is_vrf to return index
  libnetlink: Add variant of rtnl_talk that does not display RTNETLINK
    answers error
  Introduce ip vrf command

 include/bpf_util.h   |   6 ++
 include/libbpf.h     | 184 ++++++++++++++++++++++++++++++++
 include/libnetlink.h |   3 +
 include/utils.h      |   4 +
 ip/Makefile          |   3 +-
 ip/ip.c              |   4 +-
 ip/ip_common.h       |   4 +-
 ip/iplink_vrf.c      |  29 ++++--
 ip/ipnetns.c         |  34 ------
 ip/ipvrf.c           | 289 +++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/Makefile         |   2 +-
 lib/bpf.c            |  71 ++++++++-----
 lib/exec.c           |  41 ++++++++
 lib/fs.c             | 143 +++++++++++++++++++++++++
 lib/libnetlink.c     |  20 +++-
 man/man8/ip-vrf.8    |  88 ++++++++++++++++
 16 files changed, 850 insertions(+), 75 deletions(-)
 create mode 100644 include/libbpf.h
 create mode 100644 ip/ipvrf.c
 create mode 100644 lib/exec.c
 create mode 100644 lib/fs.c
 create mode 100644 man/man8/ip-vrf.8

-- 
2.1.4