passt/pasta was incorrectly dropping UDP packets with a zero-length
payload when travelling out via the tap interface.  This is incorrect,
since for a datagram protocol, zero-length packets are still
meaningful.

Based on my earlier series for test command dispatch, user namespace
cleanup and test temporary file handling.

Bugzilla: https://bugs.passt.top/show_bug.cgi?id=19

Changes since v1:
 * Also remove unnecessary initialization of mm[]

David Gibson (3):
  udp: Don't pre-initialize msghdr array
  udp: Don't drop zero-length outbound UDP packets
  test: Simpler termination handling for UDP tests

 test/passt/udp       | 23 +++++++-------
 test/passt_in_ns/udp | 73 ++++++++++++++++++++++----------------------
 test/pasta/udp       | 31 +++++++++----------
 udp.c                | 23 +++++++++-----
 4 files changed, 77 insertions(+), 73 deletions(-)

-- 
2.37.3