ArjenandGitHub
f624013b83
Access layer for phones and laptops to reach FIPS routers on OpenWrt, stacked on the 802.11s mesh backhaul from #123. Squashed from five commits by Arjen (Origami74); their original messages follow. * feat(openwrt): open !FIPS access SSID — fips-ap-setup helper, default transport binding, how-to Client access layer for phones and laptops: every FIPS router broadcasts the same open SSID ('!FIPS' — the leading '!' sorts it to the top of alphabetically ordered network pickers), forming one standard ESS. Clients save it once and roam between all FIPS routers natively, with FIPS's Noise IK handshake as the only security layer: - fips-ap-setup: opt-in UCI helper that creates the 'fips-ap0' open AP (encryption none — security type must be uniform across routers or clients treat the ESS as different saved networks), an isolated network with a static ULA /64, RA-only odhcpd addressing (stateless SLAAC, no DHCP — the minimum that satisfies Android's provisioning check; no internet by design, so phones keep cellular as default route), and a locked-down fips_ap firewall zone (no path to br-lan or the WAN; only ICMPv6, mDNS, and the FIPS transports reachable). 'remove' subcommand undoes it. Radio setup stays opt-in; a package must not commandeer radios on install. - fips.yaml: ship 'ap0'/'ap1' Ethernet-transport entries commented out (matching the 802.11s mesh backhaul) so a stock install that never creates fips-ap* logs no per-boot "interface missing" bind warning; fips-ap-setup uncomments the matching block when it creates the interface and re-comments it on remove. - Regression test: extend shipped_openwrt_config_parses to assert the ap0/ap1 entries ship commented out and still parse once uncommented, alongside mesh0/mesh1. - Packaging: install the helper in ipk/apk/buildroot (three synced copies), extend CI structural checks and shellcheck targets. - docs/how-to/set-up-open-access-ssid.md: full guide, including the one-time 'no internet, stay connected' acceptance (stored per SSID, covers every FIPS router) and the security-type-uniformity constraint. * docs(openwrt): correct open-SSID/mesh security framing — peering is open by design The fips-ap-setup/fips-mesh-setup comments and both how-tos claimed a stranger "cannot pass the FIPS handshake" / "their frames die at the handshake" / the handshake surface "drops them". That is wrong: FIPS peer admission is open. An inbound handshake from any net-new identity is promoted (node::handlers::handshake::promote_connection), gated only by the daemon's max-peers cap — there is no allowlist, no PSK, and the AuthChallenge path is not wired to admission. The Noise IK handshake provides authentication (no impersonation of another identity, no MITM), not authorization. Restate the model accurately in all five places: a stranger on the open SSID (or the open mesh) can associate AND form a FIPS peer link — that is the point of open access. Containment is the isolated fips_ap zone (no path to br-lan or the WAN) plus the max-peers cap, not the handshake. Clarify that AP client isolation is an L2 control only: a peered stranger is an overlay peer like any other, so the FIPS overlay, not L2, is the trust boundary between clients. * feat(openwrt): serve DHCPv4 on the access SSID from a fixed roamable subnet RA-only addressing satisfied Android's provisioning check but left anything expecting IPv4 with a self-assigned address and a "no IP" complaint. dnsmasq now leases out of 10.21.<N>.0/24 (N = radio index; prefix echoes FIPS port 2121), deliberately identical on every router: a roaming client keeps its lease across the ESS, and dnsmasq's authoritative mode — the OpenWrt default, pinned by the helper — ACKs the renew a foreign router never issued. Lease collisions across routers surface as a NAK on renew and the client re-DHCPs. The dhcp section's 'dhcpv4 server' is read by both dnsmasq (default images) and odhcpd (only with maindhcp), so either arrangement serves. A DHCPv4/udp-67 accept rule joins the fips_ap zone; DHCPv6 stays off, the ULA RA stays as-is, and nothing depends on an upstream. The zone remains isolated — no forwardings, no internet. * feat(openwrt): enable mDNS rendezvous from fips-ap-setup Phone FIPS apps cannot open raw-Ethernet sockets, so DNS-SD is how they find the router's daemon — but node.rendezvous.lan defaults to off. Ship the lan block commented in fips.yaml (consistent with the apN transport entries) and have fips-ap-setup uncomment it when creating the access SSID. The awk match is scoped to node.rendezvous because transports.ethernet carries a 'lan' entry at the same indent. The switch is daemon-wide, so 'remove' deliberately leaves it on rather than guess whether other transports rely on it. * fix(openwrt): bind UDP dual-stack [::]:2121 so access-SSID clients reach it The shipped router config bound the UDP transport "0.0.0.0:2121" (IPv4 wildcard) while the mDNS LAN advert announces every interface address, including the router's IPv6 link-local — which phones on the !FIPS access SSID rightly prefer (their cellular default route swallows v4, and fd00::/8 is captured by the Myco mesh TUN). Result: the client's Noise msg1 arrives on an unbound v6 port and is silently lost; the handshake resends and times out. Symptom chain (observed on-device): mDNS resolve OK, platform push OK, "Sent Noise handshake message 1" to [fe80::…%N]:2121, four resends, no reply, 30 s stale-timeout. OpenWrt is Linux (bindv6only=0), so "[::]" accepts IPv4 via v4-mapped addresses too — nothing is lost. packaging/common is deliberately left on "0.0.0.0" for now: Windows defaults IPV6_V6ONLY=1, where "[::]" would drop v4 instead.
FIPS OpenWrt Package (apk)
Builds a FIPS .apk for OpenWrt 25+, where apk-tools is the mandatory
package manager. apk is also available opt-in on 24.10 (where opkg remains
the default). For OpenWrt 24.x and earlier, the .ipk package in
../openwrt-ipk/ still works.
Like the .ipk build, this is SDK-free: it cross-compiles with
cargo-zigbuild and assembles the package directly — no OpenWrt SDK image. The
.ipk format is a plain tar.gz we can hand-roll, but the .apk (apk-tools v3
ADB) container is not, so we drive the official apk mkpkg applet — the same
tool OpenWrt's own include/package-pack.mk
calls. The only extra requirement over the .ipk build is the apk binary.
Layout
| File | Purpose |
|---|---|
build-apk.sh |
Cross-compile + assemble the .apk via apk mkpkg |
apk-version.sh |
Map a release tag / commit height to an apk-tools-valid version |
apk-version.test.sh |
Case-table test for apk-version.sh (sh apk-version.test.sh) |
The installed-filesystem payload (init scripts, fips.yaml, sysctl drop-ins,
hotplug, uci-defaults, …) is shared with the .ipk package — there is one
canonical copy in ../openwrt-ipk/files/. build-apk.sh
stages from there, so the two packages always ship the same files. Keep the
staging block in build-apk.sh in sync with ../openwrt-ipk/build-ipk.sh.
Versioning
apk-tools enforces a strict version grammar
(<digit>(.<digit>)*(_<suffix><digit>*)*(-r<N>)). apk-version.sh builds a
valid version from structured inputs rather than rewriting an already-flattened
string:
| Input | apk version |
|---|---|
tag v1.2.3 |
1.2.3-r0 |
tag v1.2.3-rc1 |
1.2.3_rc1-r0 |
dev 1234 (commit height) |
0.0.0_git1234-r0 |
The human-readable version (v1.2.3, master.123.abcdef0) is still used for the
artifact filename; only the metadata embedded in the package is normalized.
Building
Prerequisites
| Requirement | Notes |
|---|---|
cargo install cargo-zigbuild + zig |
Rust musl cross-compilation (as for .ipk) |
apk-tools v3 apk binary |
Provides apk mkpkg; not packaged for most distros — build from source |
fakeroot |
Optional; makes packaged files root-owned on an unprivileged build host |
apk-tools is not in Debian/Ubuntu repos, so build the pinned release from source.
Pin the same commit the targeted OpenWrt release ships (see
package/system/apk/Makefile upstream) so the .apk is readable by the device's
apk. CI builds 3.0.5 (b5a31c0d…):
sudo apt-get install -y build-essential meson ninja-build pkg-config \
zlib1g-dev libssl-dev libzstd-dev liblzma-dev lua5.4-dev scdoc
git clone https://gitlab.alpinelinux.org/alpine/apk-tools.git
cd apk-tools && git checkout b5a31c0d865342ad80be10d68f1bb3d3ad9b0866
meson setup build && ninja -C build src/apk
export APK_BIN="$PWD/build/src/apk"
Build the package
# from the repo root
./packaging/openwrt-apk/build-apk.sh --arch aarch64 # or x86_64, mipsel, mips, arm
Output: dist/fips_<version>_<openwrt-arch>.apk. Override the version with
PKG_VERSION (filename) and APK_VERSION (embedded metadata); otherwise both are
derived from git.
Installing on the router
Packages are unsigned (the same posture as our .ipk), so install with
--allow-untrusted:
scp -O dist/fips_<version>_<arch>.apk root@192.168.1.1:/tmp/
ssh root@192.168.1.1 apk add --allow-untrusted /tmp/fips_<version>_<arch>.apk
On OpenWrt 25.x, installing from a signed repository requires the publisher's
key; a single --allow-untrusted package install does not. If we ever publish an
apk feed, add ECDSA (prime256v1) signing via apk mkpkg --sign and distribute the
public key to /etc/apk/keys/.
/etc/fips/fips.yaml is marked as a config file (via
/lib/apk/packages/fips.conffiles), so apk preserves local edits across upgrades,
and /lib/upgrade/keep.d/fips preserves /etc/fips/ across sysupgrade — the
same guarantees as the .ipk package.