Server sends COMMAND_SCREEN_PREVIEW_REQ when user double-clicks an
active (non-Locked/Inactive) host that advertises CLIENT_CAP_SCREEN_PREVIEW.
Client BitBlts primary screen, encodes to JPEG via GDI+ and replies. The
existing STATIC tooltip is replaced with a self-drawn CPreviewTipWnd
showing the thumbnail above the host info text, with wide-character
rendering so the popup also works on non-Chinese servers.
- Quality tiers reuse QualityProfile pattern: PreviewProfile + 6 levels
driven by GetTargetQualityLevel (FRP-aware), with 4K/ultrawide auto
upscale on Ultra/High tiers up to min(screenWidth/4, 1280).
- Client limits to 1 in-flight capture via atomic counter to defend
against flood/DoS; Send2Server is already mutex-serialized.
- Server validates responses by reqId only (single in-flight tip);
4s arrival timeout marks "preview unavailable" without blocking the
text fallback path.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Client first packet on every sub-connection signs (clientID || timestamp ||
nonce) and waits for server ack. Server verifies signature and pins clientID
on the sub-connection ctx, eliminating IP-reverse-lookup unreliability for
NAT/localhost scenarios. Sub-conn coverage: Win 12 sites, Linux/macOS 3-4
each. Main connection keeps existing TOKEN_LOGIN flow unchanged.
Includes:
- Protocol structs sized to 512/256 bytes with reserved space for future
extensions (locale, OS info, session token, etc.)
- 5-min timestamp tolerance (Kerberos-grade replay window)
- 10-sec client wait for cross-pacific / weak-network tolerance
- Fix RemoveFromHostList side-effect ordering: MarkDeviceOffline and
m_ActiveWndW.erase now only fire when ctx is actually removed from
m_HostList, preventing sub-conn disconnects from misreporting main as
offline (regression introduced by auth-set clientID on sub ctx)
- Fix latent bug: IOCPClient::m_conn was never assigned in ctor, leaving
GetConnectionAddress() always NULL and FileManager V2 transfer's
srcClientID always 0
Breaking change: new client cannot use sub-features against old server.
New server tolerates legacy clients (no auth). Future tightening can reject
unauthenticated sub-connections via IsAuthenticated() flag.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
