When the slicer and printer are on different VLANs, Bambu Studio could
not send prints through the proxy because the printer's real IP leaked
through MQTT payloads, the bind protocol forwarded the real printer's
identity, the port 6000 file transfer tunnel was not proxied, and FTP
data connections raced the TLS handshake on zero-byte uploads.
- Rewrite IP addresses in MQTT PUBLISH payloads (string + integer)
with proper packet framing and cross-chunk buffering
- Respond to bind/detect with VP identity via BindServer
- Add TLS proxy for port 6000 (file transfer tunnel)
- Buffer slicer FTP data during printer connection setup
- Advertise configured VP name in SSDP proxy
- Add cross-subnet SSDP wildcard listener for VPN setups
- Register UserEmailPreference model in models/__init__.py
- Add 11 unit tests for MQTT rewrite, IP conversion, SSDP name
When running multiple virtual printers with different access codes on
separate bind IPs, FTP connections were always routed to the wrong VP.
Root cause: the iptables REDIRECT rule (990→9990) rewrites the
destination IP to the incoming interface's primary address. With Linux's
weak host model (arp_filter=0), packets for secondary IPs arrive on the
primary interface, and REDIRECT sends them all to the first VP's FTP
server. MQTT was unaffected because port 8883 had no redirect.
Fix: FTP server now binds directly to port 990 (standard implicit FTPS),
eliminating the iptables redirect entirely. Requires CAP_NET_BIND_SERVICE
(already set in the systemd service file and Docker image).
Also removed a global asyncio set_exception_handler() in the MQTT server
that was overwritten by each VP instance, causing spurious "Unhandled
exception in client_connected_cb" errors on startup.
Changes:
- FTP_PORT: 9990 → 990 (ftp_server.py)
- Removed set_exception_handler() from MQTT server
- Updated Dockerfile, docker-compose.yml port mappings
- Deprecated --redirect-990 in install script
- Updated wiki: removed iptables instructions for all platforms
- Added migration guide (docs/migration-vp-ftp-port.md)
- Added unit tests for port constant and no-global-state invariant
X1C and X1 virtual printers used legacy SSDP model codes
(3DPrinter-X1-Carbon, 3DPrinter-X1) that BambuStudio doesn't
recognize, causing "incompatible printer preset" errors when
sending prints. Changed to the correct codes (BL-P001, BL-P002)
that real printers report via SSDP.
Also fixed proxy mode auto-inherit storing printer display names
(e.g. "X1C") instead of SSDP codes, by adding a resolution layer
that maps display names to model codes.
DB migration auto-converts existing VPs on startup.
Virtual printers in Queue mode now have an "Auto-dispatch" setting.
When enabled (default), prints start automatically — preserving current
behavior. When disabled, prints are added with manual_start so they
wait for manual dispatch from the queue UI.
BambuStudio uses TLS on port 3002 for certain printer models (e.g. A1
Mini / N1). The bind server only spoke plain TCP on both ports, so the
TLS ClientHello was rejected as "invalid frame" and the slicer could
never discover or connect to the virtual printer.
Port 3002 now uses TLS (reusing the VP's existing certificate), port
3000 remains plain TCP. Also updated proxy-mode to use TLSProxy for
the port 3002 bind proxy instead of raw TCPProxy.
sync_from_db() skipped VPs already in self._instances without checking
if their config had changed. Mode, model, access code, bind IP, remote
interface IP, and target printer changes were silently ignored until
manual toggle off/on or full restart. Now detects config drift and
restarts affected instances.
The H2C dual nozzle variant reports model code O1C2 via MQTT, but only
O1C was recognized. This caused the camera to use the wrong protocol
(chamber image on port 6000 instead of RTSP on port 322), producing a
reconnect loop. Added O1C2 to all model ID maps across 8 files.
When a virtual printer auto-queued a file, PrintQueueItem was created
without plate_id. The scheduler defaulted to plate_id=1, generating
MQTT path "Metadata/plate_1.gcode". For multi-plate 3MF files sliced
on a different plate, the printer couldn't find the gcode and returned
HMS error 0500_4003. Extract plate index from the 3MF's slice_info.config
before creating the queue item.
Virtual printer "print_queue" mode created queue items with no printer
assignment. Now sets target_model from the VP's SSDP model code (e.g.
P1S, X1C) for "Any Printer" scheduling, or uses target_printer_id if
configured.
Settings page auto-save onSuccess overwrote localSettings with the
server response, discarding characters typed during the save request.
Removed the stale state overwrite so in-progress input is preserved.
Recent BambuStudio/OrcaSlicer updates require a bind/detect handshake on
port 3000 before connecting via MQTT/FTP. Without this, slicers cannot
discover or connect to the virtual printer in any mode.
- Add BindServer for server modes (immediate/review/print_queue)
- Add TCPProxy for raw TCP forwarding (proxy mode)
- Update Dockerfile (EXPOSE 3000) and docker-compose.yml (bridge port)
- Add 10 new tests for BindServer protocol and integration
The remote_interface_ip setting only worked in proxy mode but was
completely ignored in server modes (immediate/review/print_queue).
Users with multiple NICs (LAN + Tailscale, Docker bridges) got wrong
auto-detected IP in SSDP broadcasts and TLS certificates.
Enable Bambu Studio on a remote network to print through BamBuddy
acting as a TLS-terminating proxy for both MQTT and FTP connections.
- Add TLSProxy base class and FTPTLSProxy with PASV response rewriting,
EPSV→PASV translation, PROT P/C tracking, and one-shot data proxies
- Add SlicerProxyManager to coordinate per-slicer MQTT + FTP proxy pairs
- Support additional SAN IPs in certificate generation for proxy mode
- Broadcast SSDP on LAN B so slicers discover the proxy as a printer
- Narrow FTP passive port range to 50000-50100 with retry logic
- Expose proxy ports (8883, 9990, 50000-50100) in Dockerfile
- Document passive port range in docker-compose.yml
- SSDP proxy for cross-network setups: select slicer network interface for automatic printer discovery via SSDP relay
- FTP proxy now listens on privileged port 990 (matching Bambu Studio expectations) instead of 9990
- For systemd: requires `AmbientCapabilities=CAP_NET_BIND_SERVICE` capability
- Automatic directory permission checking at startup with clear error messages for Docker/bare metal
Proxy mode changes:
- Replace transparent TCP proxy with TLS-terminating proxy
- Slicer connects to Bambuddy cert, Bambuddy connects to printer
- Use real printer's serial number for SSDP and certificate
- This ensures MQTT topic subscriptions match the real printer
The proxy now:
1. Accepts TLS from slicer using Bambuddy's certificate
2. Opens TLS connection to real printer
3. Forwards decrypted data bidirectionally
Also: Complete i18n localization for VirtualPrinterSettings component
- Correct SSDP model codes: C11=P1P, C12=P1S, N7=P2S, C13=X1E
- Fix serial prefixes based on actual Bambu serial format
- Add confirmation modal for pending upload discard
- Sort model dropdown alphabetically, remove internal codes
- Add "Setup Required" warning with link to wiki documentation
- Update wiki with certificate installation and platform setup guides
Features:
- Configurable printer model for virtual printer emulation
- Supports X1 series (X1C, X1, X1E), P series (P1S, P1P, P2S),
A1 series (A1, A1 Mini), and H2 series (H2D, H2C, H2S)
- Dropdown in Settings > Virtual Printer to select model
- Model affects SSDP discovery and slicer compatibility
- Model change restarts virtual printer services automatically
Backend:
- Added VIRTUAL_PRINTER_MODELS mapping in manager.py
- Added virtual_printer_model setting in database
- New GET /api/v1/settings/virtual-printer/models endpoint
- Updated PUT /api/v1/settings/virtual-printer to accept model
Frontend:
- Added model dropdown to VirtualPrinterSettings component
- Status display shows selected model name
- Model change disabled while virtual printer is running
Tests:
- Added 3 unit tests for model configuration
- Updated frontend test mocks for getModels API
- Virtual printer appears in Bambu Studio/Orca Slicer via SSDP discovery
- Secure TLS/MQTT communication with auto-generated certificates
- Queue mode (pending uploads) or auto-start mode
- Configurable access code for authentication
- Docker support with network_mode: host and certificate persistence
- Fix backup/restore for virtual printer settings (auto-save no longer overwrites)
maziggy