From db5be52a4e66eecc34015048889caffc8151c655 Mon Sep 17 00:00:00 2001
From: Florian Maurer <f.maurer@outlook.de>
Date: Thu, 25 Jul 2024 23:05:55 +0200
Subject: [PATCH 1/6] ffac-update-location-gp: initial package version

* use bind and unbind to support coldplug
* restart micrond after adding service at runtime
---
 ffac-update-location-gps/Makefile             | 22 ++++++
 ffac-update-location-gps/README.md            | 22 ++++++
 .../files/etc/config/update-location-gps      |  2 +
 .../etc/hotplug.d/usb/10-update-location-gps  | 26 +++++++
 .../luasrc/usr/bin/update-location-gps        | 78 +++++++++++++++++++
 5 files changed, 150 insertions(+)
 create mode 100644 ffac-update-location-gps/Makefile
 create mode 100644 ffac-update-location-gps/README.md
 create mode 100644 ffac-update-location-gps/files/etc/config/update-location-gps
 create mode 100644 ffac-update-location-gps/files/etc/hotplug.d/usb/10-update-location-gps
 create mode 100755 ffac-update-location-gps/luasrc/usr/bin/update-location-gps

diff --git a/ffac-update-location-gps/Makefile b/ffac-update-location-gps/Makefile
new file mode 100644
index 00000000..19bd9262
--- /dev/null
+++ b/ffac-update-location-gps/Makefile
@@ -0,0 +1,22 @@
+# SPDX-FileCopyrightText: 2024 Florian Maurer, xelo
+# SPDX-License-Identifier: MIT
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=ffac-update-location-gps
+PKG_VERSION:=1.0
+PKG_RELEASE:=1
+
+PKG_LICENSE:=MIT
+
+include $(TOPDIR)/../package/gluon.mk
+
+define Package/$(PKG_NAME)
+  TITLE:=Use attached GPS controller to update location from it
+  DEPENDS:=+kmod-usb-core +kmod-usb-ohci +kmod-usb2 +kmod-usb-acm +kmod-usb-serial-pl2303 +micrond
+endef
+
+define Package/$(PKG_NAME)/description
+  If enabled, this package updates the gluon-node-info location based on the NMEA output of an attached GPS device.
+endef
+
+$(eval $(call BuildPackageGluon,$(PKG_NAME)))
diff --git a/ffac-update-location-gps/README.md b/ffac-update-location-gps/README.md
new file mode 100644
index 00000000..46955c80
--- /dev/null
+++ b/ffac-update-location-gps/README.md
@@ -0,0 +1,22 @@
+# ffac-update-location-gps
+
+This package configures gluon to update the location based on tty output of an attached GPS device.
+
+When a USB device which provides a tty is attached, it updates the location based on the output of it.
+This is done using a lua rewrite of the script from the original forum posting.
+It seems to work without coreutils-stty installed, which did fail the installation when selected as package dependency.
+
+The location is only updated in memory - and only if a valid GPS fix is available.
+After a reboot, the old location from the config is set.
+
+## hotplug limitation
+
+After a sysupgrade/autoupdate - the USB dongle has to be unplugged and plugged in once for the detection to work again.
+For reboots, this works fine as is.
+
+## further information
+
+Further information can be found here:
+
+* https://github.com/dmth/gluon-gps-locationupdate
+* https://forum.freifunk.net/t/freifunk-location-update-via-gps/1493
\ No newline at end of file
diff --git a/ffac-update-location-gps/files/etc/config/update-location-gps b/ffac-update-location-gps/files/etc/config/update-location-gps
new file mode 100644
index 00000000..cfc510dd
--- /dev/null
+++ b/ffac-update-location-gps/files/etc/config/update-location-gps
@@ -0,0 +1,2 @@
+config settings 'settings'
+	option enabled '0'
\ No newline at end of file
diff --git a/ffac-update-location-gps/files/etc/hotplug.d/usb/10-update-location-gps b/ffac-update-location-gps/files/etc/hotplug.d/usb/10-update-location-gps
new file mode 100644
index 00000000..109e4315
--- /dev/null
+++ b/ffac-update-location-gps/files/etc/hotplug.d/usb/10-update-location-gps
@@ -0,0 +1,26 @@
+#!/bin/sh
+TTYPATH="/sys${DEVPATH}/tty"
+LOCKPATH="/tmp/update-location-gps"
+
+ENABLED=$(uci get update-location-gps.settings.enabled)
+
+if [ "${ACTION}" = "bind" ]; then
+	[ "${ENABLED}" != "1" ] && exit 0
+	test -e "${LOCKPATH}" && exit 0
+	if test -e  "${TTYPATH}"; then
+		TTY_NAME=$(find "${TTYPATH}" -mindepth 1 -maxdepth 1 -type d 2>/dev/null | sed -n 's|.*/tty/||p')
+		logger -t hotplug "USB GPS device was plugged in"
+		echo "${DEVPATH}" > "${LOCKPATH}"
+		echo "*/5 * * * *  /usr/bin/update-location-gps /dev/${TTY_NAME} | logger -t update-location-gps" > "/usr/lib/micron.d/update-location-gps"
+		/etc/init.d/micrond restart
+	fi
+fi
+
+if [ "${ACTION}" = "unbind" ]; then
+	if [ "${DEVPATH}" = "$(cat ${LOCKPATH})" ]; then
+		logger -t hotplug "USB GPS device was removed"
+		rm -f "/usr/lib/micron.d/update-location-gps"
+		/etc/init.d/micrond restart
+		rm "${LOCKPATH}"
+	fi
+fi
\ No newline at end of file
diff --git a/ffac-update-location-gps/luasrc/usr/bin/update-location-gps b/ffac-update-location-gps/luasrc/usr/bin/update-location-gps
new file mode 100755
index 00000000..d60f5d86
--- /dev/null
+++ b/ffac-update-location-gps/luasrc/usr/bin/update-location-gps
@@ -0,0 +1,78 @@
+#!/usr/bin/lua
+
+if not arg[1] then
+    print("Error: No /dev/tty* path specified. Please provide a TTY device path as the first argument.")
+    os.exit(1)
+end
+
+-- Get GPS device tty
+local TTY_DEVICE = arg[1]
+
+local uci = require('simple-uci').cursor()
+
+-- Use GPS as Stream
+local file = io.open(TTY_DEVICE, "r")
+
+while true do
+    local this_line = file:read("*line")
+    if not this_line then break end  -- Exit loop if no more lines
+
+    local nc = this_line:match("^([^,]+)")
+
+    if nc == '$GPRMC' then
+        local fields = {}
+        for field in this_line:gmatch("([^,]+)") do
+            table.insert(fields, field)
+        end
+
+        local valid = fields[3]
+
+        if valid == "A" then
+            -- First: Retrieve coordinate
+            local lat = fields[4]
+            local lon = fields[6]
+
+            -- Second: Determine if coordinate is oriented North/South or East/West
+            local latdir = fields[5]
+            local londir = fields[7]
+
+            -- Split DEGREES from coordinate
+            local latdeg = tonumber(lat:sub(1, 2))
+            local londeg = tonumber(lon:sub(1, 3))
+
+            -- Split MINUTES.SECONDS from coordinate
+            local latmin = tonumber(lat:sub(3))
+            local lonmin = tonumber(lon:sub(4))
+
+            -- Convert from Degree-Minutes to Decimal-Minutes
+            local latdec = latmin / 60
+            local londec = lonmin / 60
+
+            -- Use negative notation instead of North/South or East/West
+            if latdir == 'S' then
+                latdeg = -latdeg
+            end
+            if londir == 'W' then
+                londeg = -londeg
+            end
+            lat = string.format("%f", latdeg + latdec)
+            lon = string.format("%f", londeg + londec)
+
+            print("GPS position is valid Lat/Lon:", lat, lon)
+            -- set temp location in gluon-node-info
+            uci:set('gluon-node-info', '@location[0]', 'share_location', '1')
+            uci:set('gluon-node-info', '@location[0]', 'latitude', lat)
+            uci:set('gluon-node-info', '@location[0]', 'longitude', lon)
+            uci:save('gluon-node-info')
+            -- Link to Phip's comment: https://forum.freifunk.net/t/freifunk-location-update-via-gps/1493/2
+            -- Committing here would wear out the nvram very fast, so it should not be done.
+            break
+        else
+            print("GPS position is Invalid...", valid)
+            break
+        end
+    end
+end
+
+file:close()
+os.exit(0)

From c4bbc978ce99ecfab515234fd3a40b6e5a3a4bfe Mon Sep 17 00:00:00 2001
From: Florian Maurer <fmaurer@disroot.org>
Date: Wed, 7 Aug 2024 21:38:16 +0200
Subject: [PATCH 2/6] Add check if TTY_DEVICE actually exists

Co-authored-by: Grische <2787581+grische@users.noreply.github.com>
---
 ffac-update-location-gps/luasrc/usr/bin/update-location-gps | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/ffac-update-location-gps/luasrc/usr/bin/update-location-gps b/ffac-update-location-gps/luasrc/usr/bin/update-location-gps
index d60f5d86..cd1ecf0a 100755
--- a/ffac-update-location-gps/luasrc/usr/bin/update-location-gps
+++ b/ffac-update-location-gps/luasrc/usr/bin/update-location-gps
@@ -12,6 +12,10 @@ local uci = require('simple-uci').cursor()
 
 -- Use GPS as Stream
 local file = io.open(TTY_DEVICE, "r")
+if not file then
+    print("Error: Unable to open " .. TTY_DEVICE)
+    os.exit(2)
+end
 
 while true do
     local this_line = file:read("*line")

From 983ed32728ced09f6957c24da3c12f56bfc4bbd1 Mon Sep 17 00:00:00 2001
From: Florian Maurer <f.maurer@outlook.de>
Date: Thu, 8 Aug 2024 10:57:52 +0200
Subject: [PATCH 3/6] add lock to update-location-gps lua - improve loop
 handling

---
 .../etc/hotplug.d/tty/10-update-location-gps  | 24 +++++++++++
 .../etc/hotplug.d/usb/10-update-location-gps  | 26 ------------
 .../luasrc/usr/bin/update-location-gps        | 41 ++++++++++++++++---
 3 files changed, 59 insertions(+), 32 deletions(-)
 create mode 100644 ffac-update-location-gps/files/etc/hotplug.d/tty/10-update-location-gps
 delete mode 100644 ffac-update-location-gps/files/etc/hotplug.d/usb/10-update-location-gps

diff --git a/ffac-update-location-gps/files/etc/hotplug.d/tty/10-update-location-gps b/ffac-update-location-gps/files/etc/hotplug.d/tty/10-update-location-gps
new file mode 100644
index 00000000..3fd3c086
--- /dev/null
+++ b/ffac-update-location-gps/files/etc/hotplug.d/tty/10-update-location-gps
@@ -0,0 +1,24 @@
+#!/bin/sh
+TTYPATH="/sys${DEVPATH}/tty"
+lockpath="/var/lock/update-location-gps_${DEVNAME}.lock"
+
+if [ "${ACTION}" = "add" ]; then
+	enabled=$(uci get update-location-gps.settings.enabled)
+	[ "${enabled}" != "1" ] && exit 0
+	test -e "${lockpath}" && exit 0
+	if test -e  "${TTYPATH}"; then
+		echo "hotplug-update-location-gps: TTY device ${DEVNAME} was plugged in" > /dev/kmsg
+		echo "${DEVPATH}" > "${lockpath}"
+		echo "*/5 * * * *  /usr/bin/update-location-gps /dev/${DEVNAME} | logger -t update-location-gps" > "/usr/lib/micron.d/update-location-gps_${DEVNAME}"
+		/etc/init.d/micrond restart
+	fi
+fi
+
+if [ "${ACTION}" = "remove" ]; then
+	if [ "${DEVPATH}" = "$(cat "${lockpath}")" ]; then
+		echo "hotplug-update-location-gps: TTY device ${DEVNAME} was removed" > /dev/kmsg
+		rm -f "/usr/lib/micron.d/update-location-gps_${DEVNAME}"
+		/etc/init.d/micrond restart
+		rm "${lockpath}"
+	fi
+fi
diff --git a/ffac-update-location-gps/files/etc/hotplug.d/usb/10-update-location-gps b/ffac-update-location-gps/files/etc/hotplug.d/usb/10-update-location-gps
deleted file mode 100644
index 109e4315..00000000
--- a/ffac-update-location-gps/files/etc/hotplug.d/usb/10-update-location-gps
+++ /dev/null
@@ -1,26 +0,0 @@
-#!/bin/sh
-TTYPATH="/sys${DEVPATH}/tty"
-LOCKPATH="/tmp/update-location-gps"
-
-ENABLED=$(uci get update-location-gps.settings.enabled)
-
-if [ "${ACTION}" = "bind" ]; then
-	[ "${ENABLED}" != "1" ] && exit 0
-	test -e "${LOCKPATH}" && exit 0
-	if test -e  "${TTYPATH}"; then
-		TTY_NAME=$(find "${TTYPATH}" -mindepth 1 -maxdepth 1 -type d 2>/dev/null | sed -n 's|.*/tty/||p')
-		logger -t hotplug "USB GPS device was plugged in"
-		echo "${DEVPATH}" > "${LOCKPATH}"
-		echo "*/5 * * * *  /usr/bin/update-location-gps /dev/${TTY_NAME} | logger -t update-location-gps" > "/usr/lib/micron.d/update-location-gps"
-		/etc/init.d/micrond restart
-	fi
-fi
-
-if [ "${ACTION}" = "unbind" ]; then
-	if [ "${DEVPATH}" = "$(cat ${LOCKPATH})" ]; then
-		logger -t hotplug "USB GPS device was removed"
-		rm -f "/usr/lib/micron.d/update-location-gps"
-		/etc/init.d/micrond restart
-		rm "${LOCKPATH}"
-	fi
-fi
\ No newline at end of file
diff --git a/ffac-update-location-gps/luasrc/usr/bin/update-location-gps b/ffac-update-location-gps/luasrc/usr/bin/update-location-gps
index cd1ecf0a..03c2f987 100755
--- a/ffac-update-location-gps/luasrc/usr/bin/update-location-gps
+++ b/ffac-update-location-gps/luasrc/usr/bin/update-location-gps
@@ -5,22 +5,51 @@ if not arg[1] then
     os.exit(1)
 end
 
--- Get GPS device tty
-local TTY_DEVICE = arg[1]
-
 local uci = require('simple-uci').cursor()
+local bit = require 'bit'
+local fcntl = require 'posix.fcntl'
+local unistd = require 'posix.unistd'
+
+-- Get GPS device tty
+local tty_device = arg[1]
 
 -- Use GPS as Stream
-local file = io.open(TTY_DEVICE, "r")
+local file = io.open(tty_device, "r")
 if not file then
-    print("Error: Unable to open " .. TTY_DEVICE)
+    print("Error: Unable to open " .. tty_device)
     os.exit(2)
 end
 
-while true do
+local lockfilename = "/var/lock/update-location-gps_" .. string.gsub(tty_device, "/", "_")
+
+local lockfd, err = fcntl.open(lockfilename, bit.bor(fcntl.O_WRONLY, fcntl.O_CREAT), 384) -- mode 0600
+if not lockfd then
+  print('err', err)
+  local err_verbose = string.format("Unable to get file descriptor for lock file %s .", lockfilename)
+  print('err', err_verbose)
+  os.exit(1)
+end
+
+local ok, _ = fcntl.fcntl(lockfd, fcntl.F_SETLK, {
+  l_start = 0,
+  l_len = 0,
+  l_type = fcntl.F_WRLCK,
+  l_whence = unistd.SEEK_SET,
+})
+if not ok then
+  -- silent as this is run in cron
+  os.exit(1)
+end
+
+local line_count = 0
+local max_lines = 50
+
+while line_count < max_lines do
     local this_line = file:read("*line")
     if not this_line then break end  -- Exit loop if no more lines
 
+    line_count = line_count + 1  -- Increment the line counter
+
     local nc = this_line:match("^([^,]+)")
 
     if nc == '$GPRMC' then

From 61af535f10afe15df37b43a86ad092fa1a5472aa Mon Sep 17 00:00:00 2001
From: Florian Maurer <f.maurer@outlook.de>
Date: Tue, 13 Aug 2024 20:51:27 +0200
Subject: [PATCH 4/6] do not change share_location setting

---
 ffac-update-location-gps/luasrc/usr/bin/update-location-gps | 1 -
 1 file changed, 1 deletion(-)

diff --git a/ffac-update-location-gps/luasrc/usr/bin/update-location-gps b/ffac-update-location-gps/luasrc/usr/bin/update-location-gps
index 03c2f987..30ba92de 100755
--- a/ffac-update-location-gps/luasrc/usr/bin/update-location-gps
+++ b/ffac-update-location-gps/luasrc/usr/bin/update-location-gps
@@ -93,7 +93,6 @@ while line_count < max_lines do
 
             print("GPS position is valid Lat/Lon:", lat, lon)
             -- set temp location in gluon-node-info
-            uci:set('gluon-node-info', '@location[0]', 'share_location', '1')
             uci:set('gluon-node-info', '@location[0]', 'latitude', lat)
             uci:set('gluon-node-info', '@location[0]', 'longitude', lon)
             uci:save('gluon-node-info')

From b7ba830e65d4b63a972d5e3e042902a148e8fb6a Mon Sep 17 00:00:00 2001
From: Florian Maurer <f.maurer@outlook.de>
Date: Fri, 23 Aug 2024 16:53:40 +0100
Subject: [PATCH 5/6] improve readme, rename lockfile

---
 ffac-update-location-gps/README.md                     | 10 +++++++---
 .../files/etc/hotplug.d/tty/10-update-location-gps     |  2 +-
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/ffac-update-location-gps/README.md b/ffac-update-location-gps/README.md
index 46955c80..b19eb81d 100644
--- a/ffac-update-location-gps/README.md
+++ b/ffac-update-location-gps/README.md
@@ -9,10 +9,14 @@ It seems to work without coreutils-stty installed, which did fail the installati
 The location is only updated in memory - and only if a valid GPS fix is available.
 After a reboot, the old location from the config is set.
 
-## hotplug limitation
+## behvario and lockfiles
+
+This creates a lockfile `/var/lock/hotplug-update-location-gps_$DEVNAME.lock` per found TTY device and sets up a cron job which runs every 5 minutes to check if coordinates are available from the stream.
+If the TTY is not in use, the open stream waits for the first line to be read (never) and is stuck.
+A lockfile `/var/lock/update-location-gps_$TTYDEVICE` is used to check if the cron is already running/stuck and does not start another reading terminal in that case.
+
+On creation and removal of the micron.d job, the micron.d service is restarted
 
-After a sysupgrade/autoupdate - the USB dongle has to be unplugged and plugged in once for the detection to work again.
-For reboots, this works fine as is.
 
 ## further information
 
diff --git a/ffac-update-location-gps/files/etc/hotplug.d/tty/10-update-location-gps b/ffac-update-location-gps/files/etc/hotplug.d/tty/10-update-location-gps
index 3fd3c086..6ce23938 100644
--- a/ffac-update-location-gps/files/etc/hotplug.d/tty/10-update-location-gps
+++ b/ffac-update-location-gps/files/etc/hotplug.d/tty/10-update-location-gps
@@ -1,6 +1,6 @@
 #!/bin/sh
 TTYPATH="/sys${DEVPATH}/tty"
-lockpath="/var/lock/update-location-gps_${DEVNAME}.lock"
+lockpath="/var/lock/hotplug-update-location-gps_${DEVNAME}.lock"
 
 if [ "${ACTION}" = "add" ]; then
 	enabled=$(uci get update-location-gps.settings.enabled)

From 03b0bba17cf848f91ee02cb27372cf15cb9b8c6f Mon Sep 17 00:00:00 2001
From: Florian Maurer <f.maurer@outlook.de>
Date: Thu, 29 Aug 2024 09:31:27 +0200
Subject: [PATCH 6/6] in hotplug.d/tty we already know it is a TTY device, so
 we do not need this check anymore

---
 .../files/etc/hotplug.d/tty/10-update-location-gps    | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/ffac-update-location-gps/files/etc/hotplug.d/tty/10-update-location-gps b/ffac-update-location-gps/files/etc/hotplug.d/tty/10-update-location-gps
index 6ce23938..0cf0dc2c 100644
--- a/ffac-update-location-gps/files/etc/hotplug.d/tty/10-update-location-gps
+++ b/ffac-update-location-gps/files/etc/hotplug.d/tty/10-update-location-gps
@@ -1,17 +1,14 @@
 #!/bin/sh
-TTYPATH="/sys${DEVPATH}/tty"
 lockpath="/var/lock/hotplug-update-location-gps_${DEVNAME}.lock"
 
 if [ "${ACTION}" = "add" ]; then
 	enabled=$(uci get update-location-gps.settings.enabled)
 	[ "${enabled}" != "1" ] && exit 0
 	test -e "${lockpath}" && exit 0
-	if test -e  "${TTYPATH}"; then
-		echo "hotplug-update-location-gps: TTY device ${DEVNAME} was plugged in" > /dev/kmsg
-		echo "${DEVPATH}" > "${lockpath}"
-		echo "*/5 * * * *  /usr/bin/update-location-gps /dev/${DEVNAME} | logger -t update-location-gps" > "/usr/lib/micron.d/update-location-gps_${DEVNAME}"
-		/etc/init.d/micrond restart
-	fi
+	echo "hotplug-update-location-gps: TTY device ${DEVNAME} was plugged in" > /dev/kmsg
+	echo "${DEVPATH}" > "${lockpath}"
+	echo "*/5 * * * *  /usr/bin/update-location-gps /dev/${DEVNAME} | logger -t update-location-gps" > "/usr/lib/micron.d/update-location-gps_${DEVNAME}"
+	/etc/init.d/micrond restart
 fi
 
 if [ "${ACTION}" = "remove" ]; then