connect-scan: raw non-blocking connect() + poll(POLLOUT) + SO_ERROR via std.os.linux (std.Io.net connect-with-timeout is unimplemented in 0.16); own sized std.Io.Threaded with N io.async workers off a mutex+token-bucket dispenser; --backend connect / --connect, --concurrency, --connect-timeout.
cloud/VM detection: two-socket AF_PACKET self-probe (send on one, observe the tagged frame on a second - single-socket cannot see its own send); --backend auto checks CAP_NET_RAW + egress and auto-falls-back to connect with a notice; forced raw backend disables fallback and hard-fails; zero-response raw scan hints --connect.
raw IPv6 SYN: packet.Addr union result + RFC5952 v6 render; Ipv6Hdr + pseudoChecksum6/tcpChecksum6; 128-bit SipHash cookie (generate6/seq6); parseIpv6, resolveSrcIp6 (/proc/net/if_inet6), defaultGateway6 (/proc/net/ipv6_route); Engine6 (bounded prefix, RFC6890 reserved floor, ::/0 reject, host cap); SynTemplate6; classifyTcp6 + ICMPv6 type1; ndp.zig NDP neighbor resolution; runV6Scan dispatch; connect-path v6 rides the connect engine. v6 scope = TCP SYN.
240 tests Debug+ReleaseSafe (-Dxdp on/off); KAT + two-namespace netns e2e proven on the wire; two read-only audits, 0 Critical/High/Medium, all findings fixed in-phase.
OS-realistic SYN templates (Linux/Windows/macOS/masscan JA4T option chains
plus varying IP-id), Poisson jitter, source-port rotation (RX recomputes off
the reply, zero classify changes), scoped RST-suppression (iptables plus
ambient CAP_NET_ADMIN, self-healing delete-before-insert), decoys (bogon-free
RND, real probe always sent), and FIN/NULL/Xmas/Maimon/ACK/Window flag scans
with per-mode cookie matching plus State.unfiltered.
Dead theater (idle scan, fragmentation, TTL, MAC/source-route spoof, badsum)
omitted and documented as obsolete with citations.
Cursor-based TX emission with token refund plus cold-start pacing; non-stealth
path byte-identical to M7.
PACKET_TX_RING (PACKET_MMAP, TPACKET_V2) over AF_PACKET with
PACKET_QDISC_BYPASS: socket + version + TX_RING setsockopt + mmap'd ring,
errno-gated, fail-closed on missing CAP_NET_RAW. ratelimit.zig integer
token bucket (banked-nanoseconds, no float, saturating, exact KATs).
template.zig SYN frame template: stamp dst IP/port + SipHash seq, recompute
IP + TCP checksums (reuses the M1 RFC 1071 + cookie code, both self-verify).
afpacket.zig pure Ring slot bookkeeping (inline tpacket2_hdr, comptime size
assert, reserve/fill/atomic-status, self-defending bounds, kernel-drain
reuse) split from the privileged Backend so the hot-path accounting is
unit-tested over an in-process buffer. tx.zig transmit engine generic over
an injected Sink + Clock: the M2 cyclic-group bijection is proven to survive
stamp -> ratelimit -> submit end-to-end via a fake sink + fake clock.
Privileged tx subcommand for on-hardware benchmarking (setcap + tcpdump/perf).
Green Debug + ReleaseSafe, leak-free, 45/45 tests.