tapsetup: add --loss & --delay option

[benpicco]

Contribution description

This adds an option to simulate loss links with netdev_tap

Testing procedure

Create lossy TAP interfaces

sudo dist/tools/tapsetup/tapsetup --loss 20% --delay 10ms

Start two native instances

> ping -c 100 -i 10 fe80::58b0:8ff:fe67:ad82   
12 bytes from fe80::58b0:8ff:fe67:ad82%5: icmp_seq=1 ttl=64 time=20.407 ms
12 bytes from fe80::58b0:8ff:fe67:ad82%5: icmp_seq=5 ttl=64 time=20.355 ms
12 bytes from fe80::58b0:8ff:fe67:ad82%5: icmp_seq=6 ttl=64 time=20.357 ms
…
12 bytes from fe80::58b0:8ff:fe67:ad82%5: icmp_seq=98 ttl=64 time=20.383 ms

--- fe80::58b0:8ff:fe67:ad82 PING statistics ---
100 packets transmitted, 67 packets received, 33% packet loss
round-trip min/avg/max = 20.233/20.373/20.509 ms

Note that ping measures round-trip-time, so two packets: 10 ms + 10 ms -> 20ms, 80% * 80% -> 64% success

Issues/PRs references

[kfessel]

fits the tool, fits the style and in a simple test with examples/gnrc_networking it did the thing it is supposed to do

[riot-ci]

Murdock results

✔️ PASSED

4511f3f tapsetup: add --delay option

Success	Failures	Total	Runtime
1	0	1	01m:18s

Artifacts

• Documentation preview

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