Changes

sgsn: Fix running with testenv.py podman setup

The initial testenv.py setup introduced in osmo-ttcn3-hacks.git
6baec93cb85fa8a0051e9aacd0178e90adbfdadc lacked some recent updates to
the ttcn3 testsuite setup where a second IP address is added to the
container in order to distinguish between RNC and CN in GTPU.

Change-Id: Ia0af52f8b7d61c15bdf2b6152fae27dd003d00e8

sgsn: Introduce test TC_attach_rau_a_b_wrong_old_ra

This test reproduces a crash in osmo-sgsn, and fixed in
osmo-sgsn.git Change-Id I5a4328c6e945b85dd815215724feecadba59c435.

Related: OS#6441
Change-Id: I3ce02f30a1e5becb80ab2a29f6bf5d08dd45b79c

deps/Makefile: Use upstream titan.TestPorts.SIPmsg

The patch we used from the sysmocom fork is now meged in upstream (same
git commit hash), hence we can jump back to upstream.

Related: SYS#6982
Change-Id: I8ca1252fd8710f50d8da5fb4fc105d29d9a506af

testenv: set args.podman = False if action != "run"

Fix "./testenv.py clean":

    File "/home/user/code/osmo-dev/src/osmo-ttcn3-hacks/_testenv/testenv/cmd.py", line 85, in run
      if not no_podman and testenv.args.podman:
                           ^^^^^^^^^^^^^^^^^^^
  AttributeError: 'Namespace' object has no attribute 'podman'

Change-Id: I44d5229aa481bfed13c006368d590e1486536c0e

testenv: cmd: pass all env vars without --podman

As suggested by Pau, pass all environment variables to through testenv
if it is running without podman. This way a custom TTCN3_DIR,
TTCN3_BIN_DIR and more variables that may make sense when running
directly on the host, work as expected.

Closes: OS#6544
Change-Id: I5e710a1ee7185a3f6f4f1e98f201f3f6fda2be55

S1AP_Emulation: Fix new_ctx never set when building security header

The flag was never set to true. It needs to be set to true when building
the security head of Security Mode Complete after receiving Security
Mode Command with a new EPS security context.
TS 24.301 5.4.3.3

Change-Id: I76ad46f7ee5f49698e41da729cb6422866202951

S1AP_Emulation: Fix building security headers for Integrity and Ciphering

The fact that the network instructs the UE to use EEA0 encryption (null
algo) doesn't mean the UE should mark the NAS frames in the security
header as non-ciphered. They need to be marked as IP+ciphered in the
outer header, and as plain in the inner one.

Now TTCN3 behaves like a UE recorded while executing a similar test
case. Moreover, wireshark is now happy decoding the messages.

Change-Id: Ifd4fe83e7b5aefdaafe7ce1c8b1ec6a67c65819c

testenv/README: update

Point at ./testenv.py -h and describe that everything runs in 1
container with --podman.

Change-Id: Ie9eee8cf14ba2069c1cd5bd6ab703f3f6ccdc100