slipdev: provide stdio multiplexing over SLIP

[miri64]

Contribution description

This introduces SLIPMUX like stdio multiplexing to slipdev. It can be used in conjunction with sliptty from #10477.

Testing procedure

Test border router application with USEMODULE += slipdev_stdio instead of stdio_ethos with both sliptty and tunslip. Both still should work. Also apply the testing procedures from #10477.

Also try to use tunslip with just slipdev (without slipdev_stdio). It should still work as well (just without stdio).

Issues/PRs references

Requires #10477 for interaction with Linux machine

[jnohlgard]

Tested gnrc_border_router together with #10477, and it seems to be working well. There is a problem when the Linux host has no global IPv6 address configured which messes up the return routing, see #10477 (comment)

[miri64]

Rebased to current master.

[miri64]

Rebased to current master.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. If you want me to ignore this issue, please mark it with the "State: don't stale" label. Thank you for your contributions.

[miri64]

Rebased to current master. I think it still needs adaptation for the current stdio model.

[miri64]

Adapted to current master

[benpicco]

You can also remove examples/gcoap/slipdev_params.h and tests/slip/slipdev_params.h

[benpicco]

With SLIP_BAUDRATE=2000000 stdin suffers

ifconfig
ifcfig
shell: command not found: ifcfig
> ifconfig
ifcfig
shell: command not found: ifcfig
> ifcoonnfig
ifcnnfig
shell: command not found: ifcnnfig
> ifcooonfig
ifconfig
Iface  7 
          MTU:65535  HL:64  RTR  
          RTR_ADV  
          Link type: wired
          inet6 addr: fe80::2  scope: link  VAL
          inet6 group: ff02::2
          inet6 group: ff02::1
          inet6 group: ff02::1:ff00:2
          
Iface  6  HWaddr: 71:A1  Channel: 26  Page: 0  NID: 0x23
          Long HWaddr: 5A:06:59:C9:2C:36:7D:78 
           TX-Power: 0dBm  State: IDLE  max. Retrans.: 3  CSMA Retries: 4 
          AUTOACK  ACK_REQ  CSMA  L2-PDU:102 MTU:1280  HL:64  RTR  
          RTR_ADV  6LO  IPHC  
          Source address length: 8
          Link type: wireless
          inet6 addr: fe80::5806:59c9:2c36:7d78  scope: link  VAL
          inet6 addr: 2001:db8::5806:59c9:2c36:7d78  scope: global  VAL
          inet6 group: ff02::2
          inet6 group: ff02::1
          inet6 group: ff02::1:ff36:7d78

but IP operation (e.g. ping -f) remains stable.

[miri64]

The input fd is handled last by the sliptty tool. That might be the reason for the priorisation.

[miri64]

Note to self fd6c880 is titled wrong.

[miri64]

The input fd is handled last by the sliptty tool. That might be the reason for the priorisation.

Oh wait, did you mean there is loss without any load?

[miri64]

If yes, does the same happen for stdio_uart?

[miri64]

Interesting observation (not sure it has anything to do with this): all letters of ifconfig start with a 0x6 nibble (the signifyer for an IPv6 packet):

In [5]: [hex(ord(a)) for a in "ifconfig"]                                                                                                                                                                                             
Out[5]: ['0x69', '0x66', '0x63', '0x6f', '0x6e', '0x66', '0x69', '0x67']

[benpicco]

If yes, does the same happen for stdio_uart?

Yes, also happens in gnrc_networking with CFLAGS += -DSTDIO_UART_BAUDRATE=2000000, so this is unrelated.

[benpicco]

Please squash!

[miri64]

Squashed

[miri64]

Fixed travis errors and squashed.

[miri64]

And fixed compile time errors.

[miri64]

(maybe we should add the same hack we use for start_network.sh for SLIP as we have for ethos, to add a global address to the loopback interface sweat_smile)

See #13572.