Brad FitzpatrickandBrad Fitzpatrick
420a8e5a1a
Files whose names contain characters with Unicode decompositions (such as umlauts or voiced kana) could not be opened or written over Taildrive. Background: keyboards and IMEs emit NFC (precomposed) characters on every platform, so filenames on Linux (ext4 etc) and Windows (NTFS) disks are usually NFC bytes. NFD (decomposed) names mostly come from Apple software: HFS+ forced a variant of NFD on write, and Apple's frameworks still decompose paths via fileSystemRepresentation. APFS preserves whatever bytes it is given but does normalization-insensitive lookups (it stores a hash of the normalized name), so canonically equivalent names find the same file. ext4 and NTFS lookups, by contrast, are byte-exact. On the wire, the macOS WebDAV client sends paths in NFD form (they pass through the decomposing file system representation, and unlike Apple's NFS client there is no "nfc" mount option). Windows and Linux WebDAV clients pass names through as the application provided them, typically NFC. WebDAV itself mandates no normalization, and PROPFIND hrefs reflect the server's on-disk bytes. The two forms are canonically equivalent but byte-wise different, so a macOS client requesting the NFD form of an NFC-named file on a Linux or Windows host got a 404 from the exact-byte lookup. Even against an APFS host, where the filesystem absorbs the mismatch, the client-side StatCache could still infer a 404: a cached directory listing in one form caused depth 0 PROPFINDs in the other form to be treated as not found without ever reaching the server. The inverse direction (NFD bytes on a Linux disk, copied there from a Mac, requested in NFC form by a Windows or Linux client) was broken too. Alternative regimes considered: normalizing names at storage time (as Nextcloud and Syncthing's autoNormalize do) would rename user files in shared directories as a side effect of serving them; normalizing request paths to a fixed form on the wire is unsound because the on-disk form is unknowable a priori (ext4 can hold either form, or both). Instead, adopt the APFS model: preserve bytes, but make lookups normalization-insensitive. Concretely, wrap the remote file server's webdav.Dir in a normalizingFS that, when an exact path lookup fails, rescans the parent directory for an entry whose name is canonically equivalent, comparing the NFC form of both sides (which also sidesteps Apple's nonstandard decomposition tables). Exact matches always win, and newly created files keep the exact bytes the client sent. Also NFC-normalize StatCache keys so canonically equivalent names share a cache entry. The change is covered at three levels: unit tests for the StatCache, an in-process two-node test in drive/driveimpl, and a new TestTaildrive VM integration test in tstest/natlab/vmtest that shares a directory between two Ubuntu VMs and exercises the NFC/NFD cases over the real stack with curl playing the part of a macOS WebDAV client. Fixes #15020 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com> Change-Id: I9c2f157e604efc629828581e08d5b3191dbb7d4e
Tailscale
Private WireGuard® networks made easy
Overview
This repository contains the majority of Tailscale's open source code.
Notably, it includes the tailscaled daemon and
the tailscale CLI tool. The tailscaled daemon runs on Linux, Windows,
macOS, and to varying degrees
on FreeBSD and OpenBSD. The Tailscale iOS and Android apps use this repo's
code, but this repo doesn't contain the mobile GUI code.
Other Tailscale repos of note:
- the Android app is at https://github.com/tailscale/tailscale-android
- the Synology package is at https://github.com/tailscale/tailscale-synology
- the QNAP package is at https://github.com/tailscale/tailscale-qpkg
- the Chocolatey packaging is at https://github.com/tailscale/tailscale-chocolatey
For background on which parts of Tailscale are open source and why, see https://tailscale.com/opensource/.
Using
We serve packages for a variety of distros and platforms at https://pkgs.tailscale.com.
Other clients
The macOS, iOS, and Windows clients use the code in this repository but additionally include small GUI wrappers. The GUI wrappers on non-open source platforms are themselves not open source.
Building
We always require the latest Go release, currently Go 1.26. (While we build releases with our Go fork, its use is not required.)
go install tailscale.com/cmd/tailscale{,d}
If you're packaging Tailscale for distribution, use build_dist.sh
instead, to burn commit IDs and version info into the binaries:
./build_dist.sh tailscale.com/cmd/tailscale
./build_dist.sh tailscale.com/cmd/tailscaled
If your distro has conventions that preclude the use of
build_dist.sh, please do the equivalent of what it does in your
distro's way, so that bug reports contain useful version information.
Bugs
Please file any issues about this code or the hosted service on the issue tracker.
Contributing
PRs welcome! But please file bugs. Commit messages should reference bugs.
We require Developer Certificate of
Origin
Signed-off-by lines in commits.
See commit-messages.md (or skim git log) for our commit message style.
About Us
Tailscale is primarily developed by the people at https://github.com/orgs/tailscale/people. For other contributors, see:
- https://github.com/tailscale/tailscale/graphs/contributors
- https://github.com/tailscale/tailscale-android/graphs/contributors
Legal
WireGuard is a registered trademark of Jason A. Donenfeld.