Files
DECNET/decnet/prober/probes/icmp_error_probe.py
anti f2b3393669 chore: relicense to AGPL-3.0-or-later and add SPDX headers
Replaces LICENSE (GPLv3 -> AGPLv3) and prepends
`SPDX-License-Identifier: AGPL-3.0-or-later` to every source file
across decnet/, decnet_web/, tests/, scripts/, and tools/.

Rationale: closes the GPLv3 ASP loophole so any party operating a
modified DECNET as a network service must offer their modified
source. Personal copyright (Samuel Paschuan) + inbound=outbound
contributions make a future unilateral relicense infeasible.

- LICENSE: full AGPL-3.0 text (gnu.org/licenses/agpl-3.0.txt)
- COPYRIGHT: project copyright notice
- tools/add_spdx_headers.py: idempotent header injector
  (shebang- and PEP 263-aware)

Touches 1565 source files (.py, .ts, .tsx, .js, .jsx, .css, .sh).
No behavior change; comments only.
2026-05-22 21:04:16 -04:00

74 lines
2.9 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-or-later
from __future__ import annotations
from typing import Any
from decnet.logging import get_logger
from decnet.prober.base import ActiveProbe
_log = get_logger("prober.icmp_error_probe")
class IcmpErrorProbe(ActiveProbe):
"""Port-free probe that elicits ICMP error replies from the attacker.
Sends four crafted stimuli (UDP/closed-port, TTL=1, DF+oversized, bad
IP option) and records which ICMP error classes the target emits, the
per-error RTT, and bytes echoed back in each ICMP error body.
Silent responses are as fingerprint-worthy as replies: Linux emits at
most 1 ICMP error/sec, so rate-limited absences reveal OS behaviour.
Requires root / CAP_NET_RAW. Scapy is lazy-imported inside the helper.
"""
probe_name = "icmp_error"
default_ports: list[int | None] = [None]
event_type = "icmp_error_leak"
priority = 850 # after TCP/TLS (100-200), before ipv6_leak (999)
def run(self, ip: str, port: int | None, timeout: float) -> dict[str, Any] | None:
from decnet.prober.icmp_error import elicit_icmp_errors
return elicit_icmp_errors(ip, timeout=timeout)
def syslog_fields(
self, ip: str, port: int | None, result: dict[str, Any]
) -> tuple[dict[str, Any], str]:
matrix = result.get("matrix", "")
fp_hash = result.get("fingerprint_hash", "")
errors = result.get("errors", {})
def _flag(key: str) -> str:
return "1" if errors.get(key, {}).get("returned", False) else "0"
def _rtt(key: str) -> str:
v = errors.get(key, {}).get("rtt_ms")
return str(v) if v is not None else ""
fields: dict[str, Any] = {
"icmp_matrix": matrix,
"icmp_fp_hash": fp_hash,
"icmp_port_unreach": _flag("port_unreachable"),
"icmp_time_exceeded": _flag("time_exceeded"),
"icmp_frag_needed": _flag("frag_needed"),
"icmp_param_problem": _flag("param_problem"),
"icmp_port_unreach_rtt_ms": _rtt("port_unreachable"),
"icmp_time_exceeded_rtt_ms": _rtt("time_exceeded"),
"icmp_frag_needed_rtt_ms": _rtt("frag_needed"),
"icmp_param_problem_rtt_ms": _rtt("param_problem"),
"icmp_time_exceeded_hop": errors.get("time_exceeded", {}).get("src_ip") or "",
}
msg = f"ICMP leak {ip} → matrix={matrix} fp={fp_hash[:8]}"
return fields, msg
def publish_payload(
self, ip: str, port: int | None, result: dict[str, Any]
) -> dict[str, Any]:
return {
"attacker_ip": ip,
"icmp_matrix": result.get("matrix", ""),
"icmp_fp_hash": result.get("fingerprint_hash", ""),
"errors": result.get("errors", {}),
"observed_at": result.get("observed_at", ""),
}