crypto/rand output is cryptographically secure by the Go library
documentation's promise. That, rather than strength (= passes randomness
tests) is the property that Syncthing needs).
This makes Go 1.15 test/vet happy, avoiding "conversion from untyped int
to string yields a string of one rune" warning where we do
string(KeyTypeWhatever) in namespaced.go.
It also clarifies and enforces the currently allowed range of these
numbers so I think it's fine.
This matches the convention of the stdlib and avoids ambiguity: when
customErr{} and &customErr{} both implement error, client code needs to
check for both.
Memory use should remain the same, since storing a non-pointer type in
an interface value still copies the value to the heap.
This adds some env vars to the long version string as if they were build
tags. The purpose is to better understand what code was running or not
in the version output, usage reporting and crash reports. In order to
prevent possible privacy issues the actual value of the variable is not
reported, just the fact that it was set to something non-empty.
Example:
% ./bin/syncthing --version
syncthing v1.6.1+47-g1eb104f3-buildtags "Fermium Flea" (go1.14.3 darwin-amd64) jb@kvin.kastelo.net 2020-06-03 07:25:46 UTC [stnoupgrade, use_badger]
Group the global list of files by version, instead of having one flat list for all devices. This removes lots of duplicate protocol.Vectors.
Co-authored-by: Jakob Borg <jakob@kastelo.net>
This reduces the size of our write batches before we flush them. This
has two effects: reducing the amount of data lost if we crash when
updating the database, and reducing the amount of memory used when we do
large updates without checkpoint (e.g., deleting a folder).
I ran our SyncManyFiles benchmark as it is the one doing most
transactions, however there was no relevant change in any metric (it's
limited by our fsync I expect). This is good as any visible change would
just be a decrease in performance.
I don't have a benchmark on deleting a large folder, taking that part on
trust for now...
If we fail to take the rename shortcut we may crash on a later loop,
because we do trickiness with the indexes but the original buckets[key]
in "range buckets[key]" isn't re-evaluated so i exceeds the max index.
This adds indirection of large version vectors in the same manner as we
already to block lists. The effect is the same: less duplicated data in
some situations.
To mitigate the impact for when this indirection
wouldn't be needed I've added an indirection cutoff for both blocks and
the new version vector stuff: we don't do the indirection at all for
small block lists or small version vectors, instead storing it directly
like we used to do. This is faster for small files and small setups.
Storing assets as []byte requires every compiled-in asset to be copied
into writable memory at program startup. That currently takes up 1.6MB
per syncthing process. Strings stay in the RODATA section and should be
shared between processes running the same binary.
This makes version vector values clock based instead of just incremented
from zero. The effect is that a vector that is created from scratch
(after database reset) will have a higher value for the local device
than what it could have been previously, causing a conflict. That is, if
we are A and we had
{A: 42, B: 12}
in the old scheme, a reset and rescan would give us
{A: 1}
which is a strict ancestor of the older file (this might be wrong). With
the new scheme we would instead have
{A: someClockTime, b: otherClockTime}
and the new version after reset would become
{A: someClockTime+delta}
which is in conflict with the previous entry (better).
In case the clocks are wrong (current time is less than the value in the
vector) we fall back to just simple increment like today.
This scheme is ineffective if we suffer a database reset while at the
same time setting the clock back far into the past. It's however no
worse than what we already do.
This loses the ability to emit the "added" event, as we can't look for
the magic 1 entry any more. That event was however already broken
(#5541).
Another place where we infer meaning from the vector itself is in
receive only folders, but there the only criteria is that the vector is
one item long and includes just ourselves, which remains the case with
this change.
* wip
This changes the build script to build all the things in one go
invocation, instead of one invocation per cmd. This is a lot faster
because it means more things get compiled concurrently. It's especially
a lot faster when things *don't* need to be rebuilt, possibly because it
only needs to build the dependency map and such once instead of once per
binary.
In order for this to work we need to be able to pass the same ldflags to
all the binaries. This means we can't set the program name with an
ldflag.
When it needs to rebuild everything (go clean -cache):
( ./old-build -gocmd go1.14.2 build all 2> /dev/null; ) 65.82s user 11.28s system 574% cpu 13.409 total
( ./new-build -gocmd go1.14.2 build all 2> /dev/null; ) 63.26s user 7.12s system 1220% cpu 5.766 total
On a subsequent run (nothing to build, just link the binaries):
( ./old-build -gocmd go1.14.2 build all 2> /dev/null; ) 26.58s user 7.53s system 582% cpu 5.853 total
( ./new-build -gocmd go1.14.2 build all 2> /dev/null; ) 18.66s user 2.45s system 1090% cpu 1.935 total
This makes the GC runner a service that will stop fairly quickly when
told to.
As a bonus, STTRACE=app will print the service tree on the way out,
including any errors they've flagged.
So, in a funny plot twist, it turns out that WriteFile in Go 1.13
doesn't actually set the read only bit on Windows when called with
permissions 0444 so my test was broken. With an improved test it turns
out that Rename does not, in fact, overwrite a read-only file on
Windows. This adds a fix for that.
(Rename might get improved in Go 1.15...)
This adds the functionality to run a user search with a filter for LDAP
authentication. The search is done after successful bind, as the binding
user. The typical use case is to limit authentication to users who are
member of a group or under a certain OU. For example, to only match
users in the "Syncthing" group in otherwise default Active Directory
set up for example.com:
<searchBaseDN>CN=Users,DC=example,DC=com</searchBaseDN>
<searchFilter>(&(sAMAccountName=%s)(memberOf=CN=Syncthing,CN=Users,DC=example,DC=com))</searchFilter>
The search filter is an "and" of two criteria (with the ampersand being
XML quoted),
- "(sAMAccountName=%s)" matches the user logging in
- "(memberOf=CN=Syncthing,CN=Users,DC=example,DC=com)" matches members
of the group in question.
Authentication will only proceed if the search filter matches precisely
one user.
The previous implementation was very generic; its tests didn't cover the
actual alphabet for device IDs.
Benchmark results on amd64:
name old time/op new time/op delta
Luhnify-8 1.00µs ± 1% 0.28µs ± 4% -72.38% (p=0.000 n=9+10)
Unluhnify-8 992ns ± 2% 274ns ± 1% -72.39% (p=0.000 n=10+9)
