feat: add BLE transport layer for MCUmgr over SMP

[moyamartin]

Summary

Implements BLE as a transport layer for MCUmgr commands to be sent to Zephyr/MCUboot devices over the standard SMP-over-BLE GATT service (UUID 8D53DC1D / DA2E7828)

Changes

• Adds src/ble.rs responsible for the BLE transport layer using btleplug
• Supports device discovery using MAC address (--ble-address) or by advertisement name (--ble-name)
• Handles SMP packet fragmentation across ATT notifications.
• Extends enum in transfer.rs with Ble(BleSpecs) variant.
• Adds the following arguments --ble-address, --ble-name, --ble-timeout and --ble-mtu. BLE takes precedence
  over UDP and serial in transport selection.

Note: this is only supported for BlueZ D-Bus (Linux), Windows and MacOS it is not supported yet.

Usage

./mcumgr-client --ble-name <advertising_name> <command>

On my local instance I have a device called vytal 75F1E9:

~ ./mcumgr-client --ble-name "vytal 75F1E9" list
**mcumgr-client 0.0.9

22:15:50 [INFO] Using BLE transport: scanning for 'Vytal 75F1E9'
22:15:50 [INFO] send image list request
response: {
  "images": [
    {
      "image": 0,
      "slot": 0,
      "version": "0.0.1",
      "hash": "13c0525197dedde0d68dcae7485150e18d956ab5673e56ea0ea6e24da5d901c11433ea9420b1106e197c37e623255b58d2faa11feef03179a551a919034526b1",
      "bootable": true,
      "pending": false,
      "confirmed": false,
      "active": true,
      "permanent": false
    },
    {
      "image": 0,
      "slot": 1,
      "version": "0.0.2",
      "hash": "cc834480bf4b0ea50813612baacf4e1c93cccab883d8e4515c09ccc5a03e001bff2d34809cf9eb6be83fcbd19858fdeda985266926a58734800d669ef85e0051",
      "bootable": true,
      "pending": false,
      "confirmed": true,
      "active": false,
      "permanent": false
    }
  ],
  "splitStatus": "NotApplicable**

[Frank-Buss]

Nice. I tried it as well some time ago, but got timeout problems, but I think the lib I tried supported all 3 platforms: https://github.com/vouch-opensource/mcumgr-client/tree/frankbuss/ble But BLE in general is really flaky on Linux and Windows. Only on Mac it works kind of stable. Your approach of using a lower level BlueZ lib might be the right thing for Linux.

[moyamartin]

@Frank-Buss I guess it won't hurt testing that library again. I'll push a change when I tested that succesfully. It is https://github.com/deviceplug/btleplug right? MAybe it is more stable now

[Frank-Buss]

Yes, this is the library. Looks like changes 3 months ago, so actively maintained at least. My first test of it was 3 years ago, would be nice to have it working for all 3 platforms, thanks.

[moyamartin]

@Frank-Buss I migrated to btleplug succesfully. Feel free to test this PR with another OS.