tree af678411699b6b836a334e06409de7394c2237ea
parent 134d0a386dfeb2ab276b61e82ac22c23b487cc59
author Harald Welte <laforge@gnumonks.org> 1510491673 +0900
committer Harald Welte <laforge@gnumonks.org> 1510494495 +0900

gtp_build_payload(): Support absent peer and SGSN address

When deleting a PDP context via "gtp-tunnel delete", we specify only
the gtp netdevice, the gtp version and the TID/TEI.  However, the
gtp_build_payload() function unconditionally created the netlink
attributes for GTPA_PEER_ADDRESS and GTPA_MS_ADDRESS, having their
addresses set to zero.  The kernel then tried to find a PDP context with
MS and PEER address of 0.0.0.0, and always failed with ENOENT.

The same problem also occurred with OsmoGGSN and OpenGGSN: PDP contexts
could be added but never removed.

The corresponding kernel change that requires this userland change
is the following commit introduced in 4.12-rc1:

commit d9e2dd122637034a0697bf268eed9233701b9dca
Author: Andreas Schultz <aschultz@tpip.net>
Date:   Thu Mar 9 17:43:00 2017 +0100

    gtp: unify genl_find_pdp and prepare for per socket lookup

Older kernels will work with libgtpnl both before and after this commit,
as they internally will simply disregard any attributes beyond TID/TEI.

Change-Id: Ie2ceb2cd6d2fb009bba01a05b5480c1ad775d619