- Extract newRecorderObject, checkRateLimit, sniffingDial, and
handleSniffedProtocol from the Handle method into dedicated files
(sniffing.go, util.go) to reduce Handle from ~100 to ~65 lines.
- Introduce SnifferBuilder: populated once during Init, reused via
Build() per connection. Avoids reconstructing a 9-field sniffing.Sniffer
literal on every inbound connection.
- Hoist router nil check from the lazy dial closure into Handle so
misconfigured handlers fail immediately instead of silently dropping
unrecognised traffic with no error.
- Add nil-addr guard in checkRateLimit (missing from the old inline
version — would panic if the remote address were somehow nil).
- Add comprehensive unit tests (44 tests across 5 test files) covering
handler creation, Init, metadata parsing (defaults, custom, MITM,
error paths), protocol dispatch (HTTP, TLS, unknown, empty), rate
limiting, recorder objects, dial plumbing, and SnifferBuilder.
- Add package-level godoc explaining the handler scope, limitations
vs tcp/forward, and the connection processing flow.
- Fix metadata comment: s/SnifferBuilder/sniffing.Sniffer/.
- serial/handler.go: capture xnet.Pipe return value in Handle() and forwardSerial()
- serial/handler.go: log Warnf when chain dial returns (nil,nil) before falling back
- sni/handler.go: use defer for read deadline reset to prevent stale deadline
- sni/handler.go: unrecognized protocol returns nil (clean close) instead of error
- sni/metadata.go: update readTimeout comment to reflect dual usage (deadline + SnifferBuilder)
The readTimeout field (default 15s) was being applied via xnet.Pipe to both
directions of a bidirectional proxy connection. During asymmetric transfers
(e.g. HTTP file download), the direction reading from the tunnel sees no
data after the initial request is forwarded, causing SetReadDeadline to fire
after 15s and abort the entire transfer.
Fix: add a separate idleTimeout field (default 0=disabled) to the metadata
structs in both forward/local and forward/remote handlers, and switch
xnet.Pipe to use idleTimeout instead of readTimeout. The readTimeout field
now only applies to the initial protocol sniffing/handshake phase.
Also document readTimeout vs idleTimeout semantics across all 24 locations
in the x/ module where these timeouts appear:
- readTimeout: handshake sniffing deadline (handlers), upstream response
header timeout (http.Transport), or transport-level read deadline
- idleTimeout: idle read deadline per Pipe direction (0=disabled)
- ReadTimeout on Sniffer/SnifferBuilder: upstream response header/TLS
handshake read timeout during sniffing
ginuerzh