iDevice DFU and usbmuxd Support

rickmark · May 19, 2020, 5:06am

Hey there,

I’m working on a pair of new builtin interfaces for snapd:

the ability for an official usbmuxd snap to consume USB iDevices exposed as usbmuxd that would expose a unix socket for usbmuxd connections (other snaps would consume this right)
the ability for a snap to consume USB iDevices in DFU or recovery modes.

I’m guessing the best way to do this is by creating two new “device class” builtin interfaces shamelessly copying from ADB.

Is this sounding correct?

rickmark · May 19, 2020, 5:11am

Sorry to top post - but this is the proposed patch:

gist.github.com

https://gist.github.com/rickmark/9e21e22a38d69c513c1b51c97b038d91

add_idevice.path

diff --git a/interfaces/builtin/idevice_restore.go b/interfaces/builtin/idevice_restore.go
index e69de29bb..e5e2b26aa 100644
--- a/interfaces/builtin/idevice_restore.go
+++ b/interfaces/builtin/idevice_restore.go
@@ -0,0 +1,74 @@
+// -*- Mode: Go; indent-tabs-mode: t -*-
+
+/*
+ * Copyright (C) 2018 Canonical Ltd
+ *

This file has been truncated. show original

ijohnson · May 19, 2020, 9:45am

Hi, are these devices serial over USB ports essentially? If so would the serial-port interface work for these devices?

jdstrand · May 19, 2020, 7:22pm

Yeah, as @ijohnson pointed out, the accesses seem to be a mixture of serial-port and raw-usb and there is nothing “idevice” specific to warrant a new interface. I’m curious for the answer to @ijohnson’s question (note, you might want to look at Hotplug support)

rickmark · May 19, 2020, 7:39pm

No this is a very apple specific protocol. USBMUXD is a TCP like protocol, more similar to ADB

DFU/restore is a secondary mode for devices who need firmware (the glorious connect to iTunes screen).

I want to constrain for instance a usbmuxd snap to just the udev labeled devices like “adb-support” does. usbmuxd would have a new permission to access /var/run/usbmuxd that other snaps would have to declare they use

DFU recovery is again a set of labeled udev rules.

rickmark · May 19, 2020, 7:40pm

SORRY - yeah no “serial” here mean “read the USB serial number of the device”

rickmark · May 19, 2020, 7:40pm

This patch uses udev hotplug

jdstrand · May 19, 2020, 9:14pm

Sorry, I didn’t read the udev portions closely enough. Since you are specifying very specific idProduct and idVendor, that is sufficient for this to be in separate interfaces. Please proceed with submitting a PR for this-- I’m not sure about the names of the interfaces or how we want to group the /dev/bus accesses and there will need to be more supporting comments, but this can be discussed in the PR. When you submit your PR, can you be sure to include in the PR description the output of udevadm info /dev/bus/<path>/<to>/<an>/<usbmuxd-matching-device> and udevadm info /dev/bus/<path>/<to>/<an>/<idevice-restore-matching-device>?

Thanks!