The relay engines' observable paths had no live coverage: every
capture/start call in the suite sat on a kernel anchor (AF_PACKET
capture start_kernel) and markers were only asserted on marker
add_kernel. The two relay engines' own command shapes were unit-tested
only:
* bridge engine - bridge start_capture / bridge add_packet_filter ... mark
* iol_bridge engine - iol_bridge start_capture / iol_bridge add_packet_filter ... mark
Docker relay control (bridge engine, 1 passed 33s): the capture start
REST call writes the ICMP exchange to a pcap off the relay bridge; a
mark filter attached with capture_node_id n1 signals exactly 10
marker.match events over the dedicated marker WS for 5 pings (5
requests + 5 replies, both directions), carrying node_id/link_id/tag and
the busybox frame length, writes exactly those 10 frames to the marker
pcap, and deleting the marker takes the pcap with it.
IOU relay control (iol_bridge engine, 1 passed 173s): the same two
checks on iol_bridge start_capture and the port's mark filter, driven
by the real IOS ping through the fabric socket relay.
Not duplicated in the ESW/VPCS/cloud relay controls: they issue the same
uBridge bridge commands through their own call sites, which stay covered
by unit tests; the IOL container relay goes through the same iol_bridge
engine already exercised here.
The L2-anchor spec's behavioral guarantee — an idle link stays silent for
5 s once the enslavement burst settles — only ran in the Dynamips and
Docker suites. It now also runs in QEMU, IOU, the IOL container, the
switch fast path and the switch cascade, which covers every host-device
creation path:
* tap create (Dynamips/QEMU/IOU anchors), docker create_veth (Docker host
ends; the cascade's race-loser end is hardened after create by the
server), bridge add_nio_tap (the IOL container anchor, the fifth
creator), and the brctl switch bridges, whose multicast snooping is off
precisely so the bridge role can reach silence;
* each scenario silences its guests first (IOS interfaces shut through
the console; Docker guests' links down) and re-verifies the ping after;
* the cascade measures 8 devices at once (four absorbed router anchors,
both cascade ends, both switch bridges).
IOL 158 s, cascade 293 s, ESW fast path 378 s, QEMU 428 s, IOU 308 s —
all green.
The filter matrix (cls_bpf, the eBPF classifier) only ran on Docker veth
host ends; the IOU and IOL-container scenarios now spot-check it on their
TAP anchors and prove a filter survives a node restart:
* bpf "icmp" drops everything with clsact on the anchor, both ends, and
clears back to an empty qdisc;
* frequency_drop 3 (the eBPF every-nth mode) measured 56 % round-trip
loss (1 - (2/3)^2 = 55.6 % expected) in both scenarios;
* the IOU test applies delay 100 before a router stop/start: the fresh
anchor gets netem back (tc level) and the restarted router's pings
measure RTT >= 150 ms until the filter is cleared (a re-attach that
dropped the filter would show ~100 ms).
IOU file 492 s, IOL file 182 s, both green.
Extend the docker and IOU relay negative controls with the filters the
relay itself supports (delay, frequency_drop, bpf), asserted through real
ICMP — the first live coverage of the relay filter path:
* bridge engine (docker): delay 100 grows the RTT by ~200 ms and comes
back on clear; frequency_drop 2 kills the round trips (the filter counts
every packet crossing the bridge, both directions sharing one counter,
so on an alternating ping stream one whole direction dies; verified
against uBridge directly), frequency_drop -1 blackholes, and bpf drops
by libpcap expression ('icmp', then 'greater 150' discriminating by
frame size).
* iol_bridge engine (IOU): the same delay and frequency_drop effects
through the port's iol_bridge filter list, plus the available_filters
spot check.
Docker 33 s, IOU 168 s, both green.
Two real IOU routers on a real L3 image (the image's own IOL fabric, the
real IOS CLI on the server's telnet console), driving the anchor TAPs the
kernel datapath builds on: anchors born with the node (one per Ethernet
bay/unit), real ICMP through the [fabric <-> TAP] port bridge, netem
delay, suspend, capture, link delete/re-create, node stop/start rewiring,
the serial link staying on the relay (serial bays never anchor) and a
relay negative control on an isolated instance. Every scenario ends with
no anchors, bridges or tmpdirs left behind.
harness: create_iou_node/iou_images/iou_anchor_name, and the IOS console
helper is now ios_console (dynamips, IOU and the IOL containers share it).
