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3 Commits
Author SHA1 Message Date
shadow-testandClaude Opus 5 f6e5cf3f05 Fix what review found in the skill: five real defects
Adversarial review of #29 found bugs I confirmed by reproducing each one.

**Every hand-written error message was unreachable.** `tok=$(curl ...)` is a
plain assignment, so `set -e` acts on the command substitution before the
following `|| die` can run. A wrong password produced exit 22 and no output at
all — the most likely way this gets used wrongly, and the least explained.
All four captures now go through a `run` helper that takes a *description*
rather than echoing the command, because one of them carries the account
password in `-u`.

**`up` was not idempotent, and the second run destroyed DNS.** The resolv.conf
backup was copied unconditionally, so `up --full` twice overwrote the good
backup with PIA's own resolvers; the later `down` then "restored" those and
left the container with no working DNS and no way back. `up` now runs `down`
first. Verified: two `up --full` runs, then `down`, and the backup still holds
the original 192.168.65.7.

**An empty gateway produced total connectivity loss, reported as healthy.**
`$gw` was never validated and `add_route` swallowed every failure to /dev/null.
The two half-routes need no gateway and would succeed, so the tunnel captured
everything while the exclusions keeping DNS and the Docker host reachable
silently did not exist — and `status` still printed "full tunnel". Routes are
now fatal on failure, and a via-less default (`$3` is the literal "eth0") is
rejected.

**The PIA session token was in the process arguments** — confirmed in `ps` and
/proc/*/cmdline, a ~24h bearer credential for the account readable by anything
in the container. It now goes to curl on stdin as a config. Verified: 60 polls
across a full `up`, zero sightings.

**The preflight diagnosed the wrong kernel module.** It checked /dev/net/tun
and blamed the tun module, but kernel WireGuard is a netlink interface and does
not use it — verified by creating one with NET_ADMIN and no tun device. The
check is dropped (the container could not have started without the device
anyway) and `ip link add` now reports the real dependency.

Also: a full tunnel with no DNS servers from PIA used to warn and carry on,
which is a tunnel leaking every lookup while reporting itself healthy — now
fatal. `down` validates the backup before restoring it, so a truncated one
cannot leave the container with no resolver at all. `wg.priv` is shredded on
teardown and created under umask 077, because /run rides `docker commit` into
the snapshot image. A mistyped `up --ful` is rejected instead of silently
giving a test route.

entrypoint: `install_feature_skill` gets `local`, a blank-name guard (the
disabled branch would otherwise `rm -rf` the whole skills directory under a
persisted volume), `-e`/`-L` so a leftover *file* at the destination is cleaned
up, and a chown of the parent so `claude` can still add skills of their own
when Mission Control is off. When the base image predates the skill it now says
so instead of returning silently — and `/opt/triple-c-skills` joins
FEATURE_PROBES so the migration pre-flight reports it. Docs corrected to match:
neither half reaches an existing project without a migration.

`vpn_env_var` extracted and tested, pinning the property the whole removal path
rests on — that the variable is emitted as 0 rather than omitted.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-17 16:25:12 -07:00
shadow-testandClaude Opus 5 43c7ad1478 Report which exit is which, instead of one ambiguous "public IP"
`status` probed https://1.1.1.1/cdn-cgi/trace and printed the answer as
"public IP". In test mode 1.1.1.1 is the *only* address routed into the tunnel,
so that line reported a PIA exit while every other packet left directly — a
test tunnel reading exactly like a full one.

Found on a live container: default route still via eth0, one 1.1.1.1/32 route
through pia0, and the old status line claiming a PIA public IP. This is a
plausible route to concluding the VPN is on when it is not, which is close to
the confusion this skill exists to prevent.

Status now names the mode and, in test mode, prints both exits with the real
address called out. 1.0.0.1 serves the same trace endpoint as 1.1.1.1 and is
never routed into the tunnel, so the direct exit can be probed without DNS.

Verified against all four states: no tunnel, test mode on a live tunnel that
was already up, full tunnel, and after teardown.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-17 16:24:41 -07:00
shadow-testandClaude Opus 5 70c0a8bf7a Ship a pia-vpn skill with the VPN support toggle
The toggle grants CAP_NET_ADMIN and /dev/net/tun and stops there, which users
reasonably read as "turn the VPN on" — the gap between the two is the reported
bug that the default network does not route through a VPN. Close it by giving
the container an agent-usable way to build the tunnel, rather than leaving
each project to rediscover it.

container/skills/ is baked to /opt/triple-c-skills and installed into
~/.claude/skills/ by entrypoint.sh from VPN_SUPPORT_ENABLED, mirroring how
Mission Control installs its own. Staged under /opt because ~/.claude is a
volume mount that would mask an image copy from first start.

Three details that are not incidental:

- The variable is sent as 0 rather than omitted when off, because ~/.claude
  persists: entrypoint has to be *told* to remove a skill left by an earlier
  run with the toggle on, and an absent variable cannot say that. A stale skill
  is worse than none, since it instructs an agent to use a capability the
  container no longer has.
- It is reserved in RESERVED_ENV_EXACT alongside MISSION_CONTROL_ENABLED, or a
  custom env var of the same name could claim the skill without the capability
  behind it. Covered by a test.
- The skill is re-copied on every start, rm -rf'd first, so fixes reach existing
  projects and files dropped from a later version do not linger.

The skill itself carries the three things that are easy to get wrong: that a
full tunnel captures the Docker resolver and takes DNS down with it, that an
IP-literal health check cannot see a dead resolver, and that no tunnel survives
a restart while /run state riding the snapshot makes it look as though one did.
It also states what it deliberately does not do — no killswitch, no autostart —
so an agent proposes those as decisions rather than improvising them.

pia-wg.sh preflights CAP_NET_ADMIN by capability bit rather than letting the
first `ip` call fail with a bare EPERM that points nowhere near the setting
that needs changing. Credentials stay in a file (~/pia-creds, PIA_CREDS to
override) rather than the environment, where docker inspect and every process
in the container would see them.

Tested: install/refresh/remove/no-op paths of install_feature_skill against the
real function; preflight with and without the capability; and a full up --full
/ down round trip, confirming DNS via PIA's resolvers, api.anthropic.com
reachable through the exit, and routes and resolv.conf restored on teardown.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-17 16:24:41 -07:00