# Transport

The HTTP and socket seams. What a client can do to them, and what a shutdown
can do to us.

## Closing a TCP listener can strand Accept [#679] {#accept}

Costs: during close, both `errc` and `done` are ready in `acceptLoop`'s select.
Go picks uniformly. So roughly one close in two leaves a waiting `Accept`
blocked forever on a TCP seam. Unix sockets are unaffected.
Revisit when: a daemon is seen hanging on shutdown, or before any new TCP
listener is added.
Workaround: the process usually exits anyway, which hides it.

## PTT reads an unbounded body [#688] {#ptt}

Costs: `handlePTT` does an unlimited `io.ReadAll`, and mavweb sets no header or
idle timeouts. A client can force unbounded allocation or hold a connection
open. mavgpud's half of this was fixed in V-673.
Revisit when: mavweb is reachable from anything but the tunnel.
Workaround: mavweb is not LAN-exposed today.

`/ws` rides along with this entry. It never calls `SetReadLimit`, so the
dependency default of 32,768 bytes applies, about a second of audio. Nothing
reaches it: the browser posts PCM to `/api/ptt`, and only `handlers_test.go`
opens `/ws`. It gets a caller and a real limit, or it gets deleted.

## mavweb errors cannot be traced [#689] {#errors}

Costs: some handlers return the raw internal error, which discloses internals.
Others return a generic one with no identifier, which cannot be joined to its
log line. There is no request-id middleware to join them.
Revisit when: a reported UI failure cannot be found in the log.
Workaround: read the log by timestamp.