I was working on my "dump iptables rules using only syscalls" branch and
had a bunch of C structure decoding to do. Rather than manually
calculating the padding or using unsafe trickery to actually cast
variable-length structures to Go types, I'd rather use a helper package
that deals with padding for me.
Padding rules were taken from the following article:
http://www.catb.org/esr/structure-packing/
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
In addition to printing goroutine stacks, explicitly track all in-flight
operations and print them when the watchdog triggers (along with the
time they were started at). This should make debugging watchdog failures
easier, since we can look at the longest-running operation(s) first.
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
Prior to this change, if BIRD stops responding wgengine.watchdogEngine
will crash tailscaled.
This happens because in wgengine.userspaceEngine, we end up blocking
forever trying to write a request to or read a response from BIRD with
wgLock held, and then future watchdog'd calls will block on acquiring
that mutex until the watchdog kills the process. With the timeout, we at
least get the chance to print an error message and decide whether we
want to crash or not.
Updates tailscale/coral#72
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
Add a new lookupTypeHasher function that is just a cached front-end
around the makeTypeHasher function.
We do not need to worry about the recursive type cycle issue that
made getTypeInfo more complicated since makeTypeHasher
is not directly recursive. All calls to itself happen lazily
through a sync.Once upon first use.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
The entry logic of Hash has extra complexity to make sure
we always have an addressable value on hand.
If not, we heap allocate the input.
For this reason we document that there are performance benefits
to always providing a pointer.
Rather than documenting this, just enforce it through generics.
Also, delete the unused HasherForType function.
It's an interesting use of generics, but not well tested.
We can resurrect it from code history if there's a need for it.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
This helps pprof better identify which Go kinds take the most time
since the kind is always in the function name.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
This helps pprof better identify which Go kinds take the most time
since the kind is always in the function name.
There is a minor adjustment where we hash the length of the map
to be more on the cautious side.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Rather than having two copies []fieldInfo,
just maintain one and perform merging in the same pass.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
This helps pprof better identify which Go kinds take the most time
since the kind is always in the function name.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Use of reflect.Value.SetXXX panics if the provided argument was
obtained from an unexported struct field.
Instead, pass an unsafe.Pointer around and convert to a
reflect.Value when necessary (i.e., for maps and interfaces).
Converting from unsafe.Pointer to reflect.Value guarantees that
none of the read-only bits will be populated.
When running in race mode, we attach type information to the pointer
so that we can type check every pointer operation.
This also type-checks that direct memory hashing is within
the valid range of a struct value.
We add test cases that previously caused deephash to panic,
but now pass.
Performance:
name old time/op new time/op delta
Hash 14.1µs ± 1% 14.1µs ± 1% ~ (p=0.590 n=10+9)
HashPacketFilter 2.53µs ± 2% 2.44µs ± 1% -3.79% (p=0.000 n=9+10)
TailcfgNode 1.45µs ± 1% 1.43µs ± 0% -1.36% (p=0.000 n=9+9)
HashArray 318ns ± 2% 318ns ± 2% ~ (p=0.541 n=10+10)
HashMapAcyclic 32.9µs ± 1% 31.6µs ± 1% -4.16% (p=0.000 n=10+9)
There is a slight performance gain due to the use of unsafe.Pointer
over reflect.Value methods. Also, passing an unsafe.Pointer (1 word)
on the stack is cheaper than passing a reflect.Value (3 words).
Performance gains are diminishing since SHA-256 hashing now dominates the runtime.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
When built with "deephash_debug", print the set of HashXXX methods.
Example usage:
$ go test -run=GetTypeHasher/string_slice -tags=deephash_debug
U64(2)+U64(3)+S("foo")+U64(3)+S("bar")+FIN
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Rather than separate functions to hash each kind,
just rely on the fact that these are direct memory hashable,
thus simplifying the code.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
So next time something like #5340 happens we can identify all affected
nodes and have the control plane send them health warnings.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
See https://mullvad.net/en/help/dns-over-https-and-dns-over-tls/
The Mullvad DoH servers appear to only speak HTTP/2 and
the use of a non-nil DialContext in the http.Transport
means that ForceAttemptHTTP2 must be set to true to be
able to use them.
Signed-off-by: Nahum Shalman <nahamu@gmail.com>
Every implementation of typeHasherFunc always returns true,
which implies that the slow path is no longer executed.
Delete it.
h.hashValueWithType(v, ti, ...) is deleted as it is equivalent to:
ti.hasher()(h, v)
h.hashValue(v, ...) is deleted as it is equivalent to:
ti := getTypeInfo(v.Type())
ti.hasher()(h, v)
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
also set git committer, which is apparently what this action uses for
signoff rather than git author. Remove branch-suffix, which isn't
proving useful, and add installation_id, which isn't technically
necessary in the tailscale/tailscale repo, but makes this consistent
with the workflows in other repos.
Signed-off-by: Will Norris <will@tailscale.com>
Updates #5435
Based on the discussion in #5435, we can better support transactional data models
by making the underlying storage layer a parameter (which can be specialized for
the request) rather than a long-lived member of Authority.
Now that Authority is just an instantaneous snapshot of state, we can do things
like provide idempotent methods and make it cloneable, too.
Signed-off-by: Tom DNetto <tom@tailscale.com>
It doesn't make a ton of sense for disablement to be communicated as an AUM, because
any failure in the AUM or chain mechanism will mean disablement wont function.
Instead, tracking of the disablement secrets remains inside the state machine, but
actual disablement and communication of the disablement secret is done by the caller.
Signed-off-by: Tom DNetto <tom@tailscale.com>
The CapabilityFileSharingTarget capability added by eb32847d85
is meant to control the ability to share with nodes not owned by the
current user, not to restrict all sharing (the coordination server is
not currently populating the capability at all)
Fixestailscale/corp#6669
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
This will update a licenses/tailscale.md file with all of our go
dependencies and their respective licenses. Notices for other clients
will be triggered by similar actions in other repos.
Co-authored-by: Andrew Dunham <andrew@tailscale.com>
Signed-off-by: Will Norris <will@tailscale.com>
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
`src/` is broken up into several subdirectories:
- `lib/` and `types`/ for shared code and type definitions (more code
will be moved here)
- `app/` for the existing Preact-app
- `pkg/` for the new NPM package
A new `build-pkg` esbuild-based command is added to generate the files
for the NPM package. To generate type definitions (something that esbuild
does not do), we set up `dts-bundle-generator`.
Includes additional cleanups to the Wasm type definitions (we switch to
string literals for enums, since exported const enums are hard to use
via packages).
Also allows the control URL to be set a runtime (in addition to the
current build option), so that we don't have to rebuild the package
for dev vs. prod use.
Updates #5415
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Needed to identify the node. A serverside-check the machine key (used
to authenticate the noise session) is that of the specified NodeID
ensures the authenticity of the request.
Signed-off-by: Tom DNetto <tom@tailscale.com>
When sharing nodes, the name of the sharee node is not exposed (instead
it is hardcoded to "device-of-shared-to-user"), which means that we
can't determine the tailnet of that node. Don't immediately fail when
that happens, since it only matters if "Expected-Tailnet" is used.
Signed-off-by: Will Norris <will@tailscale.com>
Add support for maps and interfaces to the fast path.
Add cycle-detection to the pointer handling logic.
This logic is mostly copied from the slow path.
A future commit will delete the slow path once
the fast path never falls back to the slow path.
Performance:
name old time/op new time/op delta
Hash-24 18.5µs ± 1% 14.9µs ± 2% -19.52% (p=0.000 n=10+10)
HashPacketFilter-24 2.54µs ± 1% 2.60µs ± 1% +2.19% (p=0.000 n=10+10)
HashMapAcyclic-24 31.6µs ± 1% 30.5µs ± 1% -3.42% (p=0.000 n=9+8)
TailcfgNode-24 1.44µs ± 2% 1.43µs ± 1% ~ (p=0.171 n=10+10)
HashArray-24 324ns ± 1% 324ns ± 2% ~ (p=0.425 n=9+9)
The additional cycle detection logic doesn't incur much slow down
since it only activates if a type is recursive, which does not apply
for any of the types that we care about.
There is a notable performance boost since we switch from the fath path
to the slow path less often. Most notably, a struct with a field that
could not be handled by the fast path would previously cause
the entire struct to go through the slow path.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
We can't write to src/ when tsconnect is used a dependency in another
repo (see also b763a12331). We therefore
need to switch from writing to src/ to using esbuild plugins to handle
the requests for wasm_exec.js (the Go JS runtime for Wasm) and the
Wasm build of the Go module.
This has the benefit of allowing Go/Wasm changes to be picked up without
restarting the server when in dev mode (Go compilation is fast enough
that we can do this on every request, CSS compilation continues to be
the long pole).
Fixes#5382
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
The Start method was removed in 4c27e2fa22, but the comment on NewConn
still mentioned it doesn't do anything until this method is called.
Signed-off-by: Kris Brandow <kris.brandow@gmail.com>
We're going to want to enable audit logging on a per-Tailnet basis. When this
happens, we want control to inform the Tailnet's clients of this capability.
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
This works around the 2.3s delay in short name lookups when SNR is
enabled.
C:\Windows\System32\drivers\etc\hosts file. We only add known hosts that
match the search domains, and we populate the list in order of
Search Domains so that our matching algorithm mimics what Windows would
otherwise do itself if SNR was off.
Updates #1659
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Several customers have had issues due to the permissions
on /dev/net. Set permissions to 0755.
Fixes https://github.com/tailscale/tailscale/issues/5048
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
There are 5 types that we care about that implement AppendTo:
key.DiscoPublic
key.NodePublic
netip.Prefix
netipx.IPRange
netip.Addr
The key types are thin wrappers around [32]byte and are memory hashable.
The netip.Prefix and netipx.IPRange types are thin wrappers over netip.Addr
and are hashable by default if netip.Addr is hashable.
The netip.Addr type is the only one with a complex structure where
the default behavior of deephash does not hash it correctly due to the presence
of the intern.Value type.
Drop support for AppendTo and instead add specialized hashing for netip.Addr
that would be semantically equivalent to == on the netip.Addr values.
The AppendTo support was already broken prior to this change.
It was fully removed (intentionally or not) in #4870.
It was partially restored in #4858 for the fast path,
but still broken in the slow path.
Just drop support for it altogether.
This does mean we lack any ability for types to self-hash themselves.
In the future we can add support for types that implement:
interface { DeepHash() Sum }
Test and fuzz cases were added for the relevant types that
used to rely on the AppendTo method.
FuzzAddr has been executed on 1 billion samples without issues.
Signed-off-by: Joe Tsai joetsai@digital-static.net
Rename Hash as Block512 to indicate that this is a general-purpose
hash.Hash for any algorithm that operates on 512-bit block sizes.
While we rename the package as hashx in this commit,
a subsequent commit will move the sha256x package to hashx.
This is done separately to avoid confusing git.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Also, rename canMemHash to typeIsMemHashable to be consistent.
There are zero changes to the semantics.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
