battery / fpc / swapping between

[iceman1001]

use case scenario,

1. hook up device on usb, run 'hf mf sim u 11223344' device is now simulating 1k mifare.
2. turn on battery
3. unconnect usb device still runs simulation, readers pics it up.
4. turn on bt,
5. from pm3 client, try to connect to pm3 over bt. this will fail, since the sim loop doesn't look for messages over fpc? (usb_valida..) even so, the last command (hf mf sim) was sent as usb, and device will only answer back to that.

[doegox]

Relates to doegox/proxmark-internal#90 doegox/proxmark-internal#96 and doegox/proxmark-internal#76

[doegox]

Not the only issue but USB comm can interrupt sim and hook again because sim looks for BUTTON and usb_poll_validate_length(). So at least we also need to check for USART data to allow sim to be interrupted.

Edit: done

[doegox]

chicken & egg:

• when USB is ripped off without care, the PM3 did not receive CMD_QUIT_SESSION so we've to make sure that no sim mode is sending any Dbprint over USB, else it'll be blocked.
• when client is terminated before unplugging USB, the CMD_QUIT_SESSION interrupts the simulation, not quite what we want

Other possibilities:

• pm3 finds out by itself that USB is gone and stops sending Dbprints
• when launching the sim command, we tell via a flag that it's for full offline mode ?

[doegox]

We still need to smooth all scenarii but for info with last commits now the original use case is working if we change the MF_DBGLEVEL:

[usb] pm3 --> hf mf dbg 0
#db# Debug level: 0          
[usb] pm3 --> hf mf sim u 11223344
[=] Mifare   | 4 byte UID  11 22 33 44            
[=] Options [ numreads: 0, flags: 2 (0x02) ]          
#db# 4B UID: 11223344          

Unplugging USB without quitting client

[!] Communicating with Proxmark3 device failed           
[=] Running in OFFLINE mode. Use "hw connect" to reconnect

[offline] pm3 --> hw connect p /dev/rfcomm0
Port:: /dev/rfcomm0  Baud:: 115200
[=] Using UART port /dev/rfcomm0           
[=] Communicating with PM3 over FPC UART           
[=] PM3 UART serial baudrate: 115200 

[fpc] pm3 --> hw ping
[=] Ping sent          
[+] Ping response received           

[iceman1001]

hf mf dbg 0, and sim still pushes messages.

#db# 4B UID: 11223344

The idea should also be that once the client connects to device again,
the debug messages from standalone mode should start sending again.

Hard to keep track of all use-cases

[doegox]

yeah but that #db# 4B UID comes immediately before you get a chance to pull USB so that's fine ;)

[iceman1001]

It should be guarded by MF_DBG_LEVEL > 0... :) It shouldn't always print.

[doegox]

true