Support for dispatchers reporting connection/disconnection events

This allows users or packages to include custom scripts under /etc/ModemManager/connection.d (for users) or /usr/lib/ModemManager/connection.d (for packages) so that they are executed whenever bearers are connected or disconnected.

The scripts will receive 4 arguments:

• Modem DBus path
• Bearer DBus path
• Data interface name
• Status string: "connected" or "disconnected"

This will help us solve https://github.com/openwrt/openwrt/issues/8368

added 19 commits

• f7b90f9f...afd3ce86 - 13 commits from branch mobile-broadband:main
• ebd3aa94 - dispatcher: new generic object to handle script dispatchers
• 7e018cf4 - dispatcher-fcc-unlock: inherit from the base dispatcher object
• c2c19140 - dispatcher-connection: new dispatcher for connection status scripts
• 96632122 - base-bearer: integrate connection status dispatcher scripts
• 512b34dd - build: rename directory where fcc unlocks are kept
• b67c6ff9 - data: add example connection dispatcher

Compare with previous version

With these changes, and the following script installed under /usr/lib/ModemManager/connection.d/10-report-down, the openwrt netifd based setup can properly detect network-initiated disconnections.

#!/bin/sh

# SPDX-License-Identifier: CC0-1.0
# 2022 Aleksander Morgado <aleksander@aleksander.es>
#
# Automatically report to netifd that the underlying modem
# is really disconnected
#
# require program name and at least 4 arguments
[ $# -lt 4 ] && exit 1

MODEM_PATH="$1"
BEARER_PATH="$2"
INTERFACE="$3"
STATE="$4"

[ "${STATE}" = "disconnected" ] || exit 0

. /usr/share/ModemManager/modemmanager.common
. /lib/netifd/netifd-proto.sh
INCLUDE_ONLY=1 . /lib/netifd/proto/modemmanager.sh

MODEM_STATUS=$(mmcli --modem="${MODEM_PATH}" --output-keyvalue)
[ -n "${MODEM_STATUS}" ] || exit 1

MODEM_DEVICE=$(modemmanager_get_field "${MODEM_STATUS}" "modem.generic.device")
[ -n "${MODEM_DEVICE}" ] || exit 2

CFG=$(mm_get_modem_config "${MODEM_DEVICE}")
[ -n "${CFG}" ] || exit 3

logger -t "modemmanager" "interface ${CFG} (network device ${INTERFACE}) ${STATE}"
proto_init_update $INTERFACE 0
proto_send_update $CFG
exit 0

Without the new dispatch script we could see how netifd was not properly notified of network-initiated disconnections:

root@OpenWrt:~# ifup wwan

root@OpenWrt:~# ip addr show dev wwan0
5: wwan0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN qlen 1000
    link/[65534] 
    inet 10.121.148.171/29 brd 10.121.148.175 scope global wwan0
       valid_lft forever preferred_lft forever
    inet6 fe80::cf29:8f18:f7d4:ec10/64 scope link flags 800 
       valid_lft forever preferred_lft forever

// simulate network-initiated disconnection by manually disconnecting the bearer

root@OpenWrt:~# mmcli -m a -K | grep bearers
modem.generic.bearers.length                    : 1
modem.generic.bearers.value[1]                  : /org/freedesktop/ModemManager1/Bearer/15

root@OpenWrt:~# mmcli -b 15 --disconnect
successfully disconnected the bearer

// network interface still has IP settings (wrong!)

root@OpenWrt:~# ip addr show dev wwan0
5: wwan0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN qlen 1000
    link/[65534] 
    inet 10.121.148.171/29 brd 10.121.148.175 scope global wwan0
       valid_lft forever preferred_lft forever
    inet6 fe80::cf29:8f18:f7d4:ec10/64 scope link flags 800 
       valid_lft forever preferred_lft forever

// interface status still reports connected (wrong!)

root@OpenWrt:~# ifstatus wwan
{
	"up": true,
	"pending": false,
	"available": true,
	"autostart": true,
	"dynamic": false,
	"uptime": 52,
	"l3_device": "wwan0",
	"proto": "modemmanager",
        .....

After installing the new connection dispatcher script, we can see how netifd gets notified about the disconnection successfully:

root@OpenWrt:~# ifup wwan

root@OpenWrt:~# ip addr show dev wwan0
5: wwan0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN qlen 1000
    link/[65534] 
    inet 10.120.109.253/30 brd 10.120.109.255 scope global wwan0
       valid_lft forever preferred_lft forever
    inet6 fe80::cf29:8f18:f7d4:ec10/64 scope link flags 800 
       valid_lft forever preferred_lft forever

// simulate network-initiated disconnection by manually disconnecting the bearer

root@OpenWrt:~# mmcli -m a -K | grep bearers
modem.generic.bearers.length                    : 1
modem.generic.bearers.value[1]                  : /org/freedesktop/ModemManager1/Bearer/13

root@OpenWrt:~# mmcli -b 13 --disconnect
successfully disconnected the bearer

// network interface doesn't have IP settings (right!)

root@OpenWrt:~# ip addr show dev wwan0
5: wwan0: <POINTOPOINT,MULTICAST,NOARP> mtu 1500 qdisc fq_codel state DOWN qlen 1000
    link/[65534] 

// interface status is disconnected (right!)

root@OpenWrt:~# ifstatus wwan
{
	"up": false,
	"pending": true,
	"available": true,
	"autostart": true,
	"dynamic": false,
	"proto": "modemmanager",
	"data": {
		
	}
}

added Ready for review label

added 16 commits

• b67c6ff9...1fec1cd3 - 10 commits from branch mobile-broadband:main
• 01c8edf6 - dispatcher: new generic object to handle script dispatchers
• e188a77e - dispatcher-fcc-unlock: inherit from the base dispatcher object
• e8612671 - dispatcher-connection: new dispatcher for connection status scripts
• 2dafb32d - base-bearer: integrate connection status dispatcher scripts
• 99232154 - build: rename directory where fcc unlocks are kept
• 7960b365 - data: add example connection dispatcher

Compare with previous version

approved this merge request

enabled an automatic merge when the pipeline for 7960b365 succeeds

merged

removed Ready for review label