Consume uBridge's ebpf_modes contract (feature/tc-window 40c36ae): a
stateful mode is usable iff ebpf=1 and its token is listed; builds
predating the field keep their shipped modes (nth/quota/flow), so the
pre-correction window semantics can never be installed silently.
- gns3server/utils/tc_capabilities.py: shared reply parser, mode
policy and filter-type mappings (compute and controller gate on the
same rules)
- gns3server/compute/ubridge/tc_probe.py: standalone probe spawning a
throwaway uBridge as the server's own user, cached by binary
identity (path/mtime/size - the version string cannot distinguish
rebuilds); failures cache as unknown
- GET /v3/compute/capabilities gains ubridge_tc {netem, ebpf,
ebpf_modes, cbpf}; the controller forwards it (Compute.capabilities)
and available_filters hides kernel-datapath filter types an endpoint
compute cannot run (both ends apply their own filters, so one
incapable compute hides the type); computes without a report keep
the full list and apply-time 409 stays the guard
- docker: _ubridge_apply_ebpf_drops gates per mode token; the cleanup
path only sends "off" for modes the build declares
- split DockerVM's kernel-datapath machinery (veth lifecycle, carrier,
marker primitives, tc filter translation, kernel NIO teardown) into
compute/docker/docker_kernel_datapath.py (DockerKernelDatapathMixin)
uBridge's window mode gained the semantics the B.2 spec asked for —
`tc window_drop <if> <start> <outage> <pct> [<period> [<jitter>]]`: a
single outage that traffic passes before *and* after, recurring flaps
with period >= outage, and a per-cycle jitter — so the kernel-only
`window_drop` filter type is now exposed:
- validation mirrors the tc grammar (3-5 params, ranges, period >=
outage, jitter cap) and adds window_drop to KERNEL_ONLY_FILTERS;
filter_inactive_filters keeps start=0 — unlike every other filter a
zero first parameter means "the outage starts now", not "disabled".
- `_ubridge_apply_ebpf_drops` sends `tc window_drop` (positional
pass-through) and turns the mode off explicitly when absent, under the
same ebpf=1 gate.
- FILTERS entry (Start/Outage/Chance/Period/Jitter) + available_filters.
The schedule is relative to the apply: reconcile re-sets the classifier
on every apply, so any filter change, node restart or link reset restarts
the window.
Verified on a two-container kernel link, 15/15: a single outage
[1000, 1500, 100] arrives per-seq as [0..4, 13..19] (passing before the
window, dropped inside, passing after); recurring 1000/2000 ms = 52 %
round trip (duty cycle); period == outage = permanent outage; period <
outage = 409 before uBridge; jittered flap keeps the ~50 % duty cycle;
30 % chance on a permanent window = 53 % round trip against the
per-direction theory 1-0.7^2 = 51 %; coexist with netem; node restart
restores; available_filters kernel vs relay (409 + hidden); teardown
clean. P6b re-run as a regression on the same uBridge build: 13/13.
Worth recording for the next rebuild: the first delivered window program
loaded as root but reported ebpf=0 through gns3-server — the verifier's
non-root path loses the loop counter's bound, treats the catch-up loop as
unbounded and rejects the *whole* program (E2BIG, 8193 pending states),
which also took frequency_drop and quota down, with ebpf=0 as the only
symptom. Smaller trip caps did not help; the loop had to go (uBridge
572ca0c), on top of a Makefile header-dependency fix (53e34bb) that had
been shipping a stale program object.
Consume the eBPF impairment classifier delivered in uBridge
feature/tc-precision: frequency_drop becomes the exact every-Nth mode
(tc nth_drop; -1 = drop everything maps to every 1st) and the new
kernel-only quota type is the byte-cap mode (tc quota_drop, 100 = hard
cutoff). KERNEL_UNSUPPORTED_FILTERS is gone entirely — kernel/relay
eligibility is now purely topological. Both modes gate on ebpf=1 from
the per-process tc capabilities probe (error names the setcap fix); the
cleanup path (modes off) only talks to the eBPF commands when the probe
reported them. Reconcile is a plain re-set: the netem reset-before-set
already detaches the program and clears uBridge's per-interface
registry, so a mode set after it is a fresh load+attach.
Documented semantic difference: the relay counts both directions
through one bridge counter, the kernel counts per direction — N=3
round-trip loss is 1-(2/3)^2 = 55.6% on kernel vs ~1/N on relay
(measured 57%). window_drop is NOT exposed: the delivered
implementation advances the window with no gap, making 'outside the
window packets pass' unreachable (needs outage/period fields —
recorded in the spec); flow_drop awaits a parameter-shape decision.
Also fixes a pre-existing restart bug the e2e exposed: _bridges (relay
bridge names) was never cleared on stop, so restarting a node with a
relay link skipped 'bridge create' and failed on add_nio_udp.
e2e (isolated instance): 13/13 — pref-1 tc_impair classifier on both
veths, 57% round-trip for N=3, -1 = exact 100%, quota hard cutoff,
delay coexistence, clean teardown, suspend/resume, node restart,
relay-leg frequency_drop regression through an Ethernet switch. Full
suite: 1925 passed.
Surface the netem extensions delivered in uBridge feature/tc-netem-ext
as GNS3 filter types: rate (tc-style bandwidth string), reorder (needs
delay), gemodel (Gilbert-Elliot bursty loss, exclusive with
packet_loss), duplicate, seed and limit, plus the delay jitter
distribution and the loss/dup correlation parameters. All are
kernel-datapath only — the relay's packet-filter registry has no
equivalent, so available_filters hides them on relay links, setting one
on a created relay link returns 409, and the project-load path drops
them with a warning (update_filters runs before the datapath is
decided, so it cannot reject there). Validation mirrors the tc grammar:
reorder requires delay, gemodel and packet_loss are mutually exclusive,
a distribution requires jitter > 0, rate is integer+unit capped at
100gbit.
The translation in DockerVM._netem_command_parts emits the frozen
grammar order and gates extension keywords on the 'tc capabilities'
netem token list (probed once per uBridge process; a plain
delay/loss/corrupt/dup filter never probes, keeping old uBridge builds
untouched; the correl suffix has no token and gates on 'rate' as the
extension-build marker).
Reconcile became reset-before-set: the kernel's netem change merges
optional attributes (rate, correlation, reorder, corrupt, gemodel,
distribution, seed keep their previous value when the new message omits
them), so removing a parameter needs an explicit 'tc reset' — the
bpf_drop filters are re-added right after in the same flow, so the
clsact churn is invisible. The capability check runs before the reset
so a failed update leaves the previous qdisc in place.
e2e (isolated instance, kernel link): 24/24 — rate 512kbit adds exactly
2x the per-packet serialization to the RTT (45.5 ms for 1400-byte
pings), paretonormal jitter + rate-cleared leak check, reorder gap 5,
gemodel 50% bursty loss, duplicate, loss 30% correl 50%, seed 42 +
limit 5000 visible in the qdisc dump, suspend/resume and node restart
keep the filters, relay link rejects rate with 409, teardown leaves no
netem. Full unit suite: 1916 passed.
Config.update_config() applies submitted options to the main
configuration file via configparser read-modify-write: unknown
options are preserved, null removes an option, the merged view
of all files is validated as ServerConfig before anything is
written (a bad file would kill the FileWatcher polling loop),
and the write is atomic (.tmp + os.replace, mode 0600). Options
whose effective value is owned by a later configuration file
raise ConfigConflictError instead of writing a no-op. The
reload logic is factored into reload_and_notify() and the file
watcher callback is exception-guarded so polling never dies.
NotificationQueue.get only generated a synthetic ping when the queue
was idle for the full timeout. Under sustained event load (e.g. a
project with markers matching at 15-260 events/s) the queue never
idled, so compute notification streams never carried a ping and the
controller stopped emitting compute.updated: clients lost compute
statistics until the event flow paused or the server restarted.
A ping is now guaranteed at least every timeout seconds regardless of
event flow: when the ping deadline is reached the next get() returns a
ping ahead of queued events (pings only carry statistics, so skipping
ahead of real events is harmless). Both the compute stream (compute
CPU/memory/disk stats -> compute.updated) and the controller stream
(idle keepalive) benefit.
Each host interface surfaced by the cloud node now reports:
- ip_addresses: every IPv4 and IPv6 address (previously only a single
IPv4 was collected internally and then dropped before the response)
- status / speed / mtu / flags: operational state and link attributes
sourced from psutil.net_if_stats(), with flags normalized to a list
The legacy ip_address / netmask / mac_address fields are preserved so
existing callers (compute link detection, GNS3 VM, VMware, has_netmask)
keep working. The new fields travel through the existing interfaces
payload that the controller forwards verbatim, so no controller-side
change is required and the PUT / ports_mapping flow is unaffected.
This fix addresses the issue where delay: [0, X] configurations were being
silently dropped instead of returning validation errors.
Changes:
- Created new utility function filter_inactive_filters() in packet_filter_validation.py
- Implemented smart filtering logic for delay filter that checks both latency and jitter:
* delay: [0, 0] → User wants to disable delay, filter out silently
* delay: [0, X] where X > 0 → Invalid config, keep for validation error
* delay: [X, X] where X > 0 → Normal configuration, validate normally
- Simplified link.py update_filters() method to use the new utility function
- Added comprehensive tests for the new filtering logic
Before this fix:
- delay: [0, 100] would be silently dropped with no error message
- Users wouldn't know their configuration was invalid
After this fix:
- delay: [0, 100] returns proper error: "delay parameter Latency must be between 1 and 32767 ms, got: 0"
- delay: [0, 0] is correctly handled as intentional disable
- Normal delay configurations continue to work as expected
Align validation rules with ubridge source: delay latency must be > 0
(packet_filter.c delay_setup line 182). Update FILTERS definition in
link.py and test cases accordingly.
Changes:
- Replace tshark BPF validation with tcpdump -d (calls pcap_compile
internally like ubridge, returns instantly without waiting for traffic)
- Support multi-line BPF expressions: split on newlines and validate
each line individually
- Always validate, never save invalid filters on error
- Drop invalid filters during project load with warning (prevents
old topologies with bad filters from failing to open)
- Simplify test cases (no longer depend on tshark availability)
