From e5971a2375165fda8f9897b8c1019a42137bee09 Mon Sep 17 00:00:00 2001
From: Keith Whyte <keith@rhizomatica.org>
Date: Wed, 9 Jun 2021 01:29:01 +0200
Subject: [PATCH] Add LAC swapping for osmo-msc

Make LAC config availble to the shell.
Run a script on MSC restart to change the lac and write a state flag to disk.

Due to the fact that osmo-msc may restart due to crash or power outage
hence loosing all VLR state, force all UE to send a LUR by changing the LAC
on all BTS via CTRL commands to osmo-bsc.
---
 modules/rhizo_base/files/bin/swap_lac.sh      | 21 +++++++++++++++++++
 .../files/systemd/osmo-msc.override           |  1 +
 modules/rhizo_base/templates/vars.sh.erb      |  2 ++
 3 files changed, 24 insertions(+)
 create mode 100755 modules/rhizo_base/files/bin/swap_lac.sh

diff --git a/modules/rhizo_base/files/bin/swap_lac.sh b/modules/rhizo_base/files/bin/swap_lac.sh
new file mode 100755
index 0000000..8c2ee47
--- /dev/null
+++ b/modules/rhizo_base/files/bin/swap_lac.sh
@@ -0,0 +1,21 @@
+#!/bin/bash
+
+. /home/rhizomatica/bin/vars.sh
+
+_ALT_LAC=""
+if [ -f /etc/osmocom/alt_lac ]; then
+	_ALT_LAC=$(cat /etc/osmocom/alt_lac)
+fi
+
+if [ "$_ALT_LAC" == "" ]; then
+	_ALT_LAC=1
+else
+	_ALT_LAC=""
+fi
+echo $_ALT_LAC > /etc/osmocom/alt_lac
+/bin/sync
+for bts in "${!BTS[@]}" ; do
+	echo "BTS $bts:"
+	/usr/bin/osmo_ctrl.py -d 127.0.0.1 -p 4249 -s bts.$bts.location-area-code $_ALT_LAC${LAC[$bts]}
+	/usr/bin/osmo_ctrl.py -d 0 -p 4249 -s bts.$bts.send-new-system-informations 1
+done
diff --git a/modules/rhizo_base/files/systemd/osmo-msc.override b/modules/rhizo_base/files/systemd/osmo-msc.override
index 79771bc..234bf8a 100644
--- a/modules/rhizo_base/files/systemd/osmo-msc.override
+++ b/modules/rhizo_base/files/systemd/osmo-msc.override
@@ -1,3 +1,4 @@
 [Service]
 ExecStart=
 ExecStart=/usr/bin/osmo-msc -c /etc/osmocom/osmo-msc.cfg -l /var/lib/osmocom/sms.db
+ExecStartPost=/home/rhizomatica/bin/swap_lac.sh
diff --git a/modules/rhizo_base/templates/vars.sh.erb b/modules/rhizo_base/templates/vars.sh.erb
index d0f1be9..eb4c979 100644
--- a/modules/rhizo_base/templates/vars.sh.erb
+++ b/modules/rhizo_base/templates/vars.sh.erb
@@ -14,10 +14,12 @@ DID[<%= index %>]=<%= did %>
 
 #BTSs IP addresses (for amps etc)
 declare -a BTS
+declare -a LAC
 declare -a BTS_MASTER
 
 <% @bts.each_with_index do |bts, index| -%>
 BTS[<%= index %>]=<%= bts["ip"] %>
+LAC[<%= index %>]=<%= bts["lac"] %>
 <% if bts ["model"] == '2050M' -%>
 BTS_MASTER[<%= index %>]=<%= bts["ip"] %>
 <% end -%>