dosh propagates the client's TERM, but a server lacking that terminal's
terminfo (e.g. xterm-ghostty, xterm-kitty) made tmux/vim fail with
"missing or unsuitable terminal". build_shell_command now keeps the
requested TERM only when its terminfo exists on this host, otherwise falls
back to xterm-256color so remote apps always work. Affects both the
in-process and holder-spawned shells.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Make dosh terminal sessions survive a dosh-server restart
(crash/upgrade/systemctl restart): a reattaching client lands on the
SAME shell with screen state intact, instead of a fresh one.
Design: when persist_sessions is on (new config, default true) each
terminal session's shell runs in a small detached per-session holder
process (the dosh-server binary re-exec'd as `dosh-server hold`). The
holder double-forks + setsid into its own session, opens the PTY, spawns
the shell as ITS child, and serves the PTY master fd over a per-session
Unix socket via SCM_RIGHTS. The server adopts that fd to build a PtyHandle
that DETACHES (does not kill the shell) on drop, so a server exit leaves
holder + shell alive. On startup the server scans the runtime dir under
sessions_dir/run, reconnects to each live holder, receives the master fd
again, restores the persisted vt100 screen, and rebuilds the Session.
Screen/scrollback (server-memory only) is mirrored to disk atomically:
byte-throttled on the output hot path plus a 2s periodic flush, and
restored on re-adoption so reattach repaints. Truly-abandoned persistent
sessions are still reaped per the existing grace logic by asking the
holder to shut down. Anything in the persistent path failing degrades
gracefully to the original in-process shell.
PtyHandle gains an Owned (kill-on-drop, unchanged default) vs Adopted
(detach-on-drop) backing; resize on an adopted master uses TIOCSWINSZ.
No wire-format change, so protocol::VERSION stays 3. New deps: libc
(direct). New config: persist_sessions (default true); existing
integration tests pin it false to keep exercising the non-persistent
path unchanged.
Adds tests/integration_smoke.rs::session_survives_server_restart_same_
shell_and_screen: attaches, sets `cd /tmp; export MARK=...`, paints a
screen marker, KILLs the server, restarts it on the same config, reattaches
and asserts same shell pid + MARK + PWD + restored screen. Plus persist.rs
unit tests (name round-trip, screen save/load, dead-holder scan cleanup,
SCM_RIGHTS fd round-trip). cargo fmt --check and cargo test green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The native-v1 work changed the UDP wire format (HEADER_LEN 42->58) without a
version bump, so a current client silently timed out against the older
still-deployed server. The server just needed redeploying; alongside that,
fix the robustness bugs surfaced while restoring the connection:
- Server: clamp terminal size to >=1 at every PTY/parser resize site. A client
reporting a 0x0 terminal made vt100::Parser::set_size panic ("attempt to
subtract with overflow") and took down the whole single-threaded daemon.
- Client: treat size() == Ok((0,0)) like a missing size and fall back to 80x24
instead of sending 0x0 to the server.
- Reap abandoned sessions and their shells. PtyHandle now retains the child and
kills it on drop, and the cleanup task removes clientless, non-prewarmed
sessions after the grace period. Previously the shell leaked forever (one
zsh per abandoned session); prewarmed sessions still stay hot.
- Evict half-finished native handshakes (pending_native) after 30s so an
unauthenticated ClientHello flood can't grow the map without bound.
- Drop the per-client, per-packet vt100 Screen clone on the output hot path and
remove the write-only last_screen field.
- Guard load_or_create_server_secret against a <32-byte secret file (was an
index-out-of-range panic at startup).
- Reconcile stream flow-control credit (client and server) when StreamData hits
a missing writer, so a closed/unknown stream can't wedge the peer's window.
Adds a unit test for session reaping. cargo fmt + cargo test green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
DuProcess