fix: register TCPClientTunnel BindAddress as landlock.BindTCP, not ConnectTCP - #219
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fix: register TCPClientTunnel BindAddress as landlock.BindTCP, not ConnectTCP#219bkmz wants to merge 1 commit into
bkmz wants to merge 1 commit into
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…nnectTCP TCPClientTunnel listens on BindAddress (net.ListenTCP), but lockNetwork() registered it as a landlock.ConnectTCP rule instead of landlock.BindTCP. On kernels supporting Landlock network ABI v4 (Linux 6.7+), this makes wireproxy's own Landlock self-sandboxing deny its own bind() on BindAddress, regardless of host environment. Fixes windtf#218
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What
TCPClientTunnellistens onBindAddressvianet.ListenTCP(routine.go), butlockNetwork()incmd/wireproxy/main.goregistered its Landlock rule aslandlock.ConnectTCPinstead oflandlock.BindTCP— the only listening routine type that got the wrong rule (HTTPConfig,Socks5Config,SNIConfigall correctly useBindTCP).Why it matters
On kernels supporting Landlock network ABI v4 (Linux 6.7+, Jan 2024),
landlock.V4.BestEffort().RestrictNet(rules...)actually enforces these rules. SinceTCPClientTunnel's own bind was never allowlisted as a bind, the kernel denies wireproxy's ownnet.ListenTCPcall onBindAddress:This reproduces on any host/platform once the kernel is new enough — independent of Docker, cloud platform, or any external sandboxing. Full writeup with reproduction and control test in #218.
Fix
One-line: swap
ConnectTCPforBindTCPfor theTCPClientTunnelConfigcase, matching the pattern used by every other listening config type.Verified
go build ./...andgo vet ./...pass. Manually verifiedTCPClientTunnelbinds and accepts connections again after this change, on a host that previously reproduced the bug 100% of the time.Fixes #218