Hey, > > After having set up modemmanager properly, I still need to run `mmcli > simple-connect...` each time I plug in the modem. Plus, the ID sometimes > changes when re-plugging it, so I have to query the ID (sometimes the modem > takes a while to show up too), and THEN manually connect it. > > Not a huge deal TBH, but still low-key annoying; it gets repetitive rather > quickly. >
Yes, that is all expected. If you want an "automated" connection management, you need something on top of MM to do it. MM just provides APIs to control the modem, it doesn't do any logic by itself. No one is expected to run --simple-connect every time to connect a modem, there should be some other process in charge of doing that for you. > So I wrote a very little helper that listens on the D-Bus interface for new > modems, and automatically connects them to the network (sim-pin and > profile-id are read from a config file). Maybe this can be of use to others?: > > https://git.sr.ht/~whynothugo/mmctl > > Configuration of the network itself (e.g.: DHCP) is handled by the network > manager service (systemd-networkd in my case) once wlan0 is up. > Thanks for sharing! I'm sure this could be helpful to others. One thing I quickly spotted is that you're assuming DHCP can be run in the modem, and this is not always the case. Instead, you should look at the generated connected bearer object and see what are the Ip4Config and Ip6Config property values. The bearer may report "static" if the user should configure the IP settings provided by the modem in the bearer object, or "dhcp" if the user should run DHCP (or SLAAC for IPv6), or "ppp" if the user should run pppd over a specific TTY port. > Aside from sharing this very tiny tool, I wanted to also kind of suggest > incorporating this functionality into modem-manager itself; adding support > for configuration files where one can define sim-pin, profile-id, etc, and > have modem-manager automatically connect when it's detected. > This is not a task of ModemManager really. MM just provides a mean to configure the modem, it is not in charge of the actual logic to perform the connection, or what to do with the connection. Upper layers like NetworkManager (in most distros), netifd (in openwrt) or Shill (in ChromeOS) are the ones in charge of triggering the connection setup and then configuring the net interface as requested. All those upper layers already have ways to store connection settings like APN, PIN, user/pass... Adding the complexity of managing all that by MM automatically is not something I'd personally like to do. Setting up a connection, along with default routes and every other detail should be done by the network management logic in the system, be it a ethernet, a wireless or a modem device. That said, we could have a simple program like yours as an example in the ModemManager sources, or even something that could be used in setups where no other upper layer is available (e.g. assuming there will be one single default route via the modem and such). I have several examples like those that I could adapt, and ideally they would be using libmm-glib (e.g. in python via GObject Introspection). I have absolutely no idea if you can have automatic bindings like the ones we have in python or javascript via GIR when using rust, is that a thing? Cheers! -- Aleksander https://aleksander.es
