Public Access
c3dfa42108b0a56bd3d114fcc27e110b72620a52
6
Commits
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9ead42171c |
Stop a flooding remote growing the process, and let an ended session go
The terminal's memory was bounded by an argument that is not true of the SSH library underneath it, and the whole of CreditWindow's remark was that argument: the pump stops reading when the renderer falls behind, SSH's own receive window closes, the remote sshd blocks on write, and the backpressure reaches the process producing the output. The middle step does not happen. Renci.SshNet's Channels.Channel.OnData calls its window adjustment before it raises DataReceived and re-opens the channel window as soon as it drops below one packet, and ShellStream's own handler copies the bytes into a System.Net.ArrayBuffer without blocking and without a ceiling — a buffer that doubles on demand and is not given back until the stream is disposed. So a reader that stopped reading slowed the remote down by nothing at all. It only chose whose buffer the flood landed in, and it chose the one nothing bounds. Measured against the container this repository already runs sshd in: a reader that reads nothing while `yes` runs leaves ShellStream holding 8.9 MB after one second, 26.8 MB after three and 44.3 MB after five, its capacity stepping 16 → 32 → 64 MB. That is the report of "a massive memory leak on Windows"; it is not a Windows fault, it is simply where long sessions with heavy output live. The fix is to read continuously, which is what keeps SSH.NET's buffer empty, and to put the bound where it can actually be enforced. OutputBacklog is that bound: a byte-capped queue of unsent output, 4 MiB by default, which drops its oldest bytes when full and counts what it discarded. Oldest rather than newest, because the tail of a flood is the prompt somebody is waiting for. The two bounds are now separate and each is enforced where it means something. The backlog bounds what is waiting to be sent. The credit window goes on bounding what has been sent and not yet drawn — the queue inside the WebView that nothing on this side can measure — and is reserved against in the flush loop rather than the read loop. Reading is part of neither, because reading was never what the remote was waiting on. Dropping is announced rather than silent. A terminal quietly showing a different transcript from the one the remote sent is worse than one that says it could not keep up, because the second can be believed. The line goes out under its own opcode, TerminalServerOpcode.OutputDropped, rather than spliced into the output stream: what this application says about the transcript is not part of the transcript, and keeping them apart is also what makes the arithmetic hold — every byte read is either in an Output payload or counted in BytesDropped. It opens with an SGR reset, because the cut lands at an arbitrary offset and whatever escape sequence the remote was in the middle of has been left half-said. Frames are now capped at 64 KiB and taken straight into the frame buffer. The cap is the large-object-heap threshold rather than a guess — a quarter-megabyte array allocated sixty times a second is collected only by a generation 2 pass — and the direct take removes an allocation and a copy of every byte the terminal shows. The second half is the one that made the first half's cost persist. Nothing gave a session back when the remote hung up: TerminalWorkspace kept the entry, and with it an undisposed ISshConnection — an authenticated socket, its cipher state, and a keep-alive putting a packet on the wire every thirty seconds — plus the pump and SSH.NET's read buffer at whatever size the session's busiest moment had grown it to, for as long as the tab stayed open. A tab somebody typed `exit` into an hour ago was indistinguishable from a live one in everything except what it drew. ReleaseAsync disposes both, from AnnounceEndedAsync and after the announcement: the tab is told first, because tearing down an SSH connection in front of that would be latency on the one thing the user is watching for. The dictionary entry stays, because LiveSessionCount, IsSessionLive and the tab's own ENDED and RECONNECT all read it. SendInputAsync therefore asks about liveness rather than presence, since the shell channel is gone the moment the remote is. Two faults introduced on the way here and fixed, both worth naming because neither would have been visible from the outside: The read loop left through a condition on its cancellation token, and RunAsync reads a read loop that returns as the remote having closed the channel. A tab the user closed would have reported itself as a shell that exited on its own. It throws instead. With the reader finished and a renderer that had stopped acknowledging, the flush loop span: output to send, no credit to send it with, and a wait for more output that returned at once because there was some. RunAsync never completed, so the tab was never told and the connection was never released — a session invisible and permanent. The loop now leaves for the drain as soon as the backlog is complete, and RunAsync resets the credit window alongside completing it so a flusher already parked on an acknowledgement that will never come is released. Four tests asserted the old contract and now assert its reverse, which is the point rather than a relaxation — WhenCreditRunsOut_ThePumpStopsReading is now WhenCreditRunsOut_ThePumpKeepsReadingAndTheBacklogHoldsTheLine, and has to prove both halves at once. The throughput harness gained a counting transport, because a consumer that copies every frame into a 32 MB list was the slowest thing in the pipeline and a harness whose consumer cannot keep up measures itself. The fake shell gained a pace, so "a renderer that keeps up loses nothing" can be asked of a producer a network could actually deliver rather than of one running at memory bandwidth. The test that would have caught this in the first place is ARunawayRemote_KeepsBeingReadAndStaysInsideTheBacklog, and it needs the real SSH.NET and the real sshd to say anything: a fake shell hands over bytes when it is asked, and a real channel hands them over when they arrive. Under the old code its BytesRead would have stopped at exactly WindowBytes. 121 terminal tests pass over three consecutive runs with no flakes, 105 against the container, and the app, session, layout and remaining suites are unchanged and green. Manual checks 1.10a and 1.10b cover the two symptoms a person can see: a working set that plateaus under `yes`, and a connection that goes when the shell does rather than when the tab does. |
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1908189100 |
Make the terminal's right button copy and paste, and never open a menu
Selecting output and right-clicking it opened the WebView's own context menu with Copy on it, which is correct behaviour for a web page and wrong for a terminal. What a terminal's right button has meant since the Windows console got QuickEdit, and since PuTTY shipped, is this: with something selected it copies and drops the selection, with nothing selected it pastes. No menu, no second click. The gesture can only live in the page. The selection is drawn into a canvas the host never sees, and once a terminal has focus the host's window receives no input events at all — the same reason the Ctrl+plus chords are handled there. ◆ THE CLIPBOARD IS THE HOST'S IN BOTH DIRECTIONS, AND THE READING IS WHY. navigator.clipboard.readText() is gated behind the clipboard-read permission in every Chromium, and an embedded WebView with no PermissionRequested handler answers a permission request by putting a prompt on the screen. Trading a context menu for a permission dialog is not this change. So the page asks and the host answers, exactly as requestFontSizeStep does. Writing does not go the other way either, although navigator.clipboard.writeText would have worked from the page on Windows: a clipboard that is the host's in one direction and the page's in the other is two mechanisms to keep working across WebView2, WebKitGTK and Android's WebView. The host has owned a clipboard delegate since the keychain grew its COPY buttons, so each App.axaml.cs grows a ClipboardReader beside its ClipboardWriter and MainWindowViewModel takes it. Three opcodes: client ClipboardCopy and ClipboardPaste, server Clipboard. ◆ Clipboard IS NOT Paste, AND THE DIFFERENCE IS THE BRACKETING. Paste carries a snippet off the sidebar, and the page deliberately *types* a single-line one rather than bracketing it, because bash marks a bracketed paste as an active region and a snippet should read as though it had been typed. A clipboard paste is the case those markers are for — readline uses them to decide it has been pasted into — so Clipboard is always bracketed and never followed by an Enter. One opcode for both would have needed a flag meaning "which of the two kinds of paste is this", on a payload whose existing flag byte means something else. Both client frames are dispatched before the session lookup, which is what keeps the gesture working in a pane whose shell has just ended: squinting at the message a remote left behind is exactly when somebody copies the line. Dispatch was past MA0051's length once it grew a second such branch, so the frames no pump needs to see moved into Announce() and the font-size chord went with them. ◆ CAPTURED AND STOPPED, RATHER THAN MERELY PREVENTED. preventDefault alone suppresses the menu and still lets xterm's own contextmenu handler run, which moves its helper textarea under the pointer at z-index 1000 and leaves the selection sitting in it, selected. Both of those exist to serve the native menu. Taking the event in the capture phase on the pane and stopping it there is what keeps the gesture wholly the page's. rightClickSelectsWord is now false, which on macOS is a change of default rather than a restatement of it: xterm sets it true there alone, so a right-click would have selected the word under the pointer and copied that instead of pasting — wrong on one platform only, which is the worst way for it to be wrong. The renderer harness grows the pane it has been inviting since RendererReconnectionTests: a fake Terminal, the two addons, and a real UTF-8 codec, because both directions run through the page's own TextEncoder and TextDecoder and a Latin-1 stub would pass a test with an em dash in the selection. Its warning about declaring names terminal.js declares now covers the half that does not SyntaxError — a harness frame() was silently replaced by the page's frame() and failed six tests on a type error a long way from the cause. Manual checks 1.11 and 11.13 are what is left for a person: that a real contextmenu event reaches a capture listener, that no native menu is drawn once it is prevented, and that xterm's real paste() brackets. 11.13 also records what is unverified — whether Android's WebView delivers a pointer's secondary click as a contextmenu event at all. ClipboardReader is wired on that head regardless, because the alternative is a head where the paste half silently does nothing and nobody finds out; that head is not compiled here either, this machine having no android workload. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> |
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c00e5dbc5c |
Let the terminal's text be made bigger, and remember how big
Taking pinch-zoom off the phone left nothing in its place, and there was nothing on the desktop either. This is the replacement, and it is deliberately not the thing that was removed: zoom scales what has already been drawn, so the remote goes on wrapping to a width that is no longer on screen. Changing the font size refits the grid and reports the new column count, so the far end is told it has fewer columns. That round trip is the feature. The size is one number, owned by the shell. It has to be, for two reasons that pull the same way: it must survive a relaunch, and it must be reachable from a phone that has no Ctrl key to press. So the page asks and the host decides — a signed step over a new client opcode, answered with a size over a new server opcode. The phone's buttons and the desktop's chords arrive at the same place, and a size set by either is the size both remember. Stored in settings.json beside the cache rather than in it, and that is not laziness about a migration. The cache is encrypted and unreadable until a vault is unlocked, and the first terminal of a locked launch needs the size already. Nothing secret may go in that file; ClientSettings says so out loud, because the next person to add a preference is the one who needs to read it. Where it is reachable from differs per head, and only here. The phone gets A− and A+ on the connection line — not in the accessory row, which scrolls, and a control that fixes unreadable text must never be the thing that is off-screen. The desktop gets the three chords every terminal emulator has, answered by the page while a terminal has focus and by the window when it does not, plus a row in preferences that shows the current value and names the chords rather than replacing them. Someone whose terminal is too small to read is not in a position to go looking. Clamped 8 to 32. Below eight a monospace grid stops being legible and becomes a texture, and every column of it is still a column the remote is being told exists; above thirty-two a phone in portrait has too few columns to hold a prompt. The buttons disable at the ends rather than accepting presses that do nothing, which on a terminal reads as the application having stopped responding. The preferences screen's header comment claimed none of the design's terminal settings could be saved, and listed the three things that were missing to make one work. All three now exist, so it says which one is real and why the other five still are not. Verified with the protocol suite — including that the step byte round-trips signed, since read unsigned a step down arrives as 255 and clamps to the largest font, making "smaller" do the most dramatic available version of "larger" — a data-plane test that the chord is heard with no session registered, and five shell tests: the default matches the renderer's, both clamps hold, reset works, and a size chosen in one shell is there in a second one over the same profile directory. Layout suite and both heads build. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
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d07b336868 |
Free the terminal from the Hosts screen, and fill the room it left
The WebView sat inside the Hosts grid, so navigating to Files or the keychain hid every open terminal and the strip that named them. A connection you had opened was invisible from four of the five screens. The window now has two surfaces rather than one: a nav rail that says which page you are on, and a terminal strip that is always there and switches the whole content area to a shell. Screen keeps meaning "which page" and never becomes a sixth kind of page, which is why this is two properties instead of one enum with a terminal member in it. Every screen lives inside one wrapper panel that collapses when a terminal is showing. That is not tidiness — the WebView hosts a Win32 child window that composites above everything Avalonia draws, so a screen left visible over its rectangle is a screen sliced in half, and this window has shipped that defect once already. One decision point, IsTerminalShowing, and a nested panel rather than five compound bindings nobody would remember to extend. The focus choreography is the part no test in this repo can see. Every reveal path now focuses in the same turn the WebView appeared, so all three of them post at DispatcherPriority.Loaded and let the native control re-push its bounds first. Going the other way had a real bug: the screen-changed branch called a bare Focus() where it had to release the keyboard from the native child, so switching from a terminal to Files silently ate the first keystrokes. Rare before this commit and the primary gesture after it. The tab strip grew a cross inside each tab, a plus that opens the quick-connect palette, and middle-click close. Nested buttons are correct here: Avalonia handles a left press on the cross and deliberately does not handle other buttons, which is exactly what lets middle-click bubble up from the cross as well as the tab. The test is PointerUpdateKind rather than IsMiddleButtonPressed, because the latter reports button state and is also true for a left press made while the middle button happens to be held. The handler is on the tab and not the strip, so the background closes nothing by construction. Plus opens the palette rather than a flyout, since a menu dropping into the WebView's rectangle may or may not composite above a child HWND and this repo does not make rendering claims it has not photographed. Everything a user reads now says keychain. The wire, the database and the cryptographic spec still say vault, deliberately: renaming those is a migration and a protocol change for a word. That split is written down rather than left to be rediscovered as an inconsistency. Four things that were squeezed into the keychain's category rail, or into nothing at all, now have screens. Pinned host keys get one, with fingerprints never truncated and a filter that matches them, because comparing what you have against what the operator published is the whole workflow; the approved date is read out of the item's UUIDv7 rather than added as a column, and says so, since it means first approval and not last use. Keys can be generated in the client, which needed the openssh-key-v1 container written by hand — there is no BCL or NSec helper, and the PKCS#8 route is unverified in the SSH library this uses. The armour carries no passphrase: encrypting it needs bcrypt_pbkdf, which is Blowfish with a swizzle, in a project whose crypto is otherwise entirely libsodium, for a protection the key's own remarks argue is redundant inside a vault. Generation fills the existing editor and stops, so SAVE stays the one thing that writes. ~/.ssh/config can be imported behind a preview that is ticked per row and writes nothing until the button; IdentityFile records the path and imports the key material only on an explicit opt-in, because reading somebody's private key into a vault is precisely the act this product exists to make deliberate. Match blocks and ProxyJump are reported rather than obeyed — one cannot be evaluated statically and the other has nothing behind it to route with, and a preview that implied otherwise would be worse than one that admits it. Files can be dragged in all four directions that are honestly available. Remote to Explorer does not ship and is not pretended to: the shell wants the bytes during the drop, which needs a virtual file and a native COM data object, outside what Avalonia offers. Note for the next person that Avalonia 12 replaced the drag model outright — DataObject and DataFormats are no-op stubs and IDataObject is not in the reference assembly, so every tutorial written for 11 does not compile here. Hosts can be grouped, flat and never nested. A parent id merged as a scalar lets two offline clients each re-parent A under B and B under A, producing a cycle inside an encrypted payload that no server can police and every reader would have to detect for ever. Membership lives in that payload rather than in the one plaintext concession ADR 0001 allows, whose test is that the relay cannot function without it — nothing on the server reads a group, so what plaintext would hand over is a clustering of the estate for nothing. The plaintext column reserved for it is dropped, provably always null, and the server now refuses a client that sends one; it was never populated, was copied on apply, and was not cleared on delete, so a group id would have outlived the host it described. Snippets insert through xterm rather than through the pump, because xterm is the only thing that knows whether the remote has bracketed paste on, and that is what makes a shell treat embedded newlines as text instead of as execute. The host process moves opaque bytes and never parses output, so it would have to guess, and guessing wrong runs every line. Running is off by default and the copy says the text goes into whatever is there — the terminal has no notion of being at a prompt, and may be in vi or at a password prompt with echo off, so the Enter the user presses themselves is the entire safety property. Connections and keychain changes are recorded as synced encrypted items, which is what makes them auditable by a team later and costs the server knowledge of connection rate and timing from row counts alone. ADR 0001 already concedes it cannot hide that class of metadata; the trade is now written into it rather than left implicit. A connection entry is written once, at close, which is what makes a synced log tractable: nothing to merge, one outbox row, no chance of colliding with itself. Live sessions come from memory, not from the log. The write is void by contract and posts to a bounded channel, because putting an encrypt-and-write on the teardown path of every session is how closing the application comes to take four seconds. A ticket opened before a lock still closes afterwards, since a shell outlives the vault. The activity log hooks the one generic repository every kind writes through, so it cannot miss a caller — which is also why the log kinds themselves declare they are not audited, or the first entry would write an entry about writing an entry. It records the names of the fields that changed and never their values; a log with an old password in it would be a plaintext credential store with no vault around it. Retention is 90 days or 5,000 entries, whichever bites first, pruned on the sync loop rather than on a second timer. That log traffic then broke the status line, which is worth recording because the fix is a shape and not a patch: background sync counted its own log rows as pushed items, so the quiet rule stopped being quiet and every action's message was overwritten a second later by a sync report. The report now separates log rows from user items and the rule reads the latter. S3 buckets appear as a remote in the file browser, behind the same interface an SFTP session implements, so the queue and both panes did not have to learn what they are talking to. Uploads go through a pipe, because the queue wants to write and the SDK wants to read; memory is then bounded by the part size instead of buffering a file to disk twice. Finally, the Windows device key store moved out of the session project, which was the one thing keeping it from being portable — everything else in it is platform-neutral, and a Windows CNG dependency in the middle of the vault code meant a second head could not reference it without dragging Windows along. The seam that made the move free was already there. docs/android-port.md is the audit behind that: what ports, what does not, in order of cost, the four decisions taken, and an inventory of every screen and state the interface has to carry, written so a design can be made from it directly. dotnet build, dotnet test and dotnet format --verify-no-changes are all clean: 1240 tests at zero warnings, including the end-to-end suite against real containers. The manual checks that headless Avalonia cannot make — the drag from Explorer, a generated key against a real host, twelve tabs at the minimum window width — are listed in docs/manual-checks.md and are still outstanding. |
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9a76eced14 |
Give hosts and terminals their own screen, and the rest of the vault another
Rebuilds the client's shell from an imported design: a titlebar and nav rail it draws itself, real multi-session tabs over the one WebView, a Ctrl+K host search, and a vault screen that merges keys, passwords and pinned host keys into one table. Hosts left the vault column for their own screen beside the terminal, which is what the design asks for and turned out to be the better split anyway. Two screens the design shows have nothing behind them yet — file transfer and teams — and say so plainly rather than rendering invented data; every other gap between the design and this build is recorded in docs/design-import-gaps.md. |
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eb354bcdd9 |
Add the SSH session layer and the terminal data plane
The throughput harness the plan requires before any UI, plus the SSH plumbing under it. 94 new tests, no WebView involved. Credit-based flow control is what makes `yes` survivable. A terminal renders at 60 Hz at best while a remote produces output as fast as the network allows, and the difference has to accumulate somewhere or be refused. Credit is reserved *before* reading, never after: because the pump cannot read more than the renderer has room for, the coalescing buffer is bounded by the window rather than by how fast the remote can talk. When credit runs out the pump stops reading, SSH's own receive window closes, and the remote sshd blocks -- backpressure to the source with no custom protocol. Verified by falsification, not just by passing: with the credit gate removed three tests fail, including the throughput harness's bounded-memory assertion. Acknowledgements are clamped because they cross into JavaScript, where a buggy or hostile page could otherwise claim to have rendered a gigabyte and talk the host into an unbounded read. Host key trust is enforced by *failing* the connection rather than prompting inside the handshake. SSH.NET raises verification synchronously, so consulting the user there would block the handshake on a UI round trip and deadlock the first time the prompt needed the UI thread. Unknown host and changed key become distinct exceptions the caller resolves asynchronously. A mismatch has no retry path at all: a dialog offering to continue is how users are trained to click through the one warning that actually indicates interception. A legitimately rebuilt server is handled by removing the pin in settings, away from the moment of connecting. The data plane serves the renderer page from the same loopback listener as the socket, which makes Origin predictable -- always http://127.0.0.1:{port} -- where a WebView virtual-host mapping would give a different origin per backend and nothing to validate. The token is substituted at serve time, so it never touches disk and never appears in a URL. Being clear about what that buys: not protection from a process running as this user, which can read our memory anyway, but from a page in the user's browser attempting WebSocket connections to loopback ports, which is a real and routine thing. Two bugs the tests caught. The accept loop handled connections serially, so an upgraded WebSocket parked it inside the receive loop and every later request went unanswered -- the page's own script among them. The suite hung rather than failed, which is how I found it. And SHA-1 is unavoidable here: RFC 6455 mandates it for Sec-WebSocket-Accept, where it authenticates nothing. Suppressed narrowly with that reasoning; the alternative, HttpListener.AcceptWebSocketAsync, throws PlatformNotSupportedException off Windows. |