[PATCH bpf-next v2 0/8] xdp: Avoid unloading xdp prog not attached by sample

[Maciej Fijalkowski <maciejromanfijalkowski@gmail.com>]

Hi!
This patchset tries to address the situation where:
* user loads a particular xdp sample application that does stats polling
* user loads another sample application on the same interface
* then, user sends SIGINT/SIGTERM to the app that was attached as a first one
* second application ends up with an unloaded xdp program

1st patch contains a helper libbpf function for getting the map fd by a
given map name.
2nd patch adds a support for getting a program to load based on index. This
was added for xdp_redirect_cpu purposes.
In patch 3 Jesper removes the read_trace_pipe usage from xdp_redirect_cpu which
was a blocker for converting this sample to libbpf usage.
4th patch updates a bunch of xdp samples to make the use of libbpf.
Patch 5 adjusts RLIMIT_MEMLOCK for two samples touched in this patchset.
Patch 6 makes the samples behavior similar to what iproute2 does when loading
xdp prog - the "force" flag is introduced.
Patch 7 introduces the libbpf function that will query the driver from
userspace about the currently attached xdp prog id.

Use it in samples that do polling by checking the prog id in signal handler
and comparing it with previously stored one which is the scope of 8th patch.

Thanks!

v2: include xdp_redirect_cpu into conversion

Jesper Dangaard Brouer (1):
  samples/bpf: xdp_redirect_cpu have not need for read_trace_pipe

Maciej Fijalkowski (7):
  libbpf: Add a helper for retrieving a map fd for a given name
  libbpf: Add a helper for retrieving a prog via index
  samples: bpf: Convert XDP samples to libbpf usage
  samples: bpf: Extend RLIMIT_MEMLOCK for xdp_{sample_pkts, router_ipv4}
  samples: bpf: Add a "force" flag to XDP samples
  libbpf: Add a support for getting xdp prog id on ifindex
  samples: bpf: Check the prog id before exiting

 samples/bpf/Makefile                |   8 +-
 samples/bpf/xdp1_user.c             |  29 +++++-
 samples/bpf/xdp_adjust_tail_user.c  |  33 +++++--
 samples/bpf/xdp_redirect_cpu_user.c | 142 +++++++++++++++++++++---------
 samples/bpf/xdp_redirect_map_user.c |  94 ++++++++++++++++----
 samples/bpf/xdp_redirect_user.c     |  92 +++++++++++++++----
 samples/bpf/xdp_router_ipv4_user.c  | 171 +++++++++++++++++++++++++-----------
 samples/bpf/xdp_rxq_info_user.c     |  36 ++++++--
 samples/bpf/xdp_sample_pkts_user.c  |  76 +++++++++++++---
 samples/bpf/xdp_tx_iptunnel_user.c  |  66 ++++++++++----
 samples/bpf/xdpsock_user.c          |  25 +++++-
 tools/lib/bpf/libbpf.c              |  20 +++++
 tools/lib/bpf/libbpf.h              |   7 ++
 tools/lib/bpf/libbpf.map            |   6 ++
 tools/lib/bpf/netlink.c             |  84 ++++++++++++++++++
 15 files changed, 710 insertions(+), 179 deletions(-)

-- 
2.16.1