The testsuite covers classic and internal BPF instructions.
It is particularly useful for JIT compiler developers.
Adds to "net" selftest target.

The testsuite can be used as a set of micro-benchmarks.
It measures execution time of each BPF program in nsec.

This patch adds core framework.
Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds a simple test case that probes the packet socket's
TPACKET_V1, TPACKET_V2 and TPACKET_V3 behavior regarding mmap(2)'ed
I/O for a small burst of 100 packets. The test currently runs for ...

  TPACKET_V1: RX_RING, TX_RING
  TPACKET_V2: RX_RING, TX_RING
  TPACKET_V3: RX_RING

... and will output on success:

  test: TPACKET_V1 with PACKET_RX_RING .................... 100 pkts (9600 bytes)
  test: TPACKET_V1 with PACKET_TX_RING .................... 100 pkts (9600 bytes)
  test: TPACKET_V2 with PACKET_RX_RING .................... 100 pkts (9600 bytes)
  test: TPACKET_V2 with PACKET_TX_RING .................... 100 pkts (9600 bytes)
  test: TPACKET_V3 with PACKET_RX_RING .................... 100 pkts (9600 bytes)
  OK. All tests passed

Reusable parts of psock_fanout.c have been put into a psock_lib.h
file for common usage. Test case successfully tested on x86_64.
Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Suggested-by: NDaniel Baluta <daniel.baluta@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Changes:
  v3->v2: rebase (no other changes)
          passes selftest
  v2->v1: read f->num_members only once
          fix bug: test rollover mode + flag

Minimize packet drop in a fanout group. If one socket is full,
roll over packets to another from the group. Maintain flow
affinity during normal load using an rxhash fanout policy, while
dispersing unexpected traffic storms that hit a single cpu, such
as spoofed-source DoS flows. Rollover breaks affinity for flows
arriving at saturated sockets during those conditions.

The patch adds a fanout policy ROLLOVER that rotates between sockets,
filling each socket before moving to the next. It also adds a fanout
flag ROLLOVER. If passed along with any other fanout policy, the
primary policy is applied until the chosen socket is full. Then,
rollover selects another socket, to delay packet drop until the
entire system is saturated.

Probing sockets is not free. Selecting the last used socket, as
rollover does, is a greedy approach that maximizes chance of
success, at the cost of extreme load imbalance. In practice, with
sufficiently long queues to absorb bursts, sockets are drained in
parallel and load balance looks uniform in `top`.

To avoid contention, scales counters with number of sockets and
accesses them lockfree. Values are bounds checked to ensure
correctness.

Tested using an application with 9 threads pinned to CPUs, one socket
per thread and sufficient busywork per packet operation to limits each
thread to handling 32 Kpps. When sent 500 Kpps single UDP stream
packets, a FANOUT_CPU setup processes 32 Kpps in total without this
patch, 270 Kpps with the patch. Tested with read() and with a packet
ring (V1).

Also, passes psock_fanout.c unit test added to selftests.
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>