Add a skeleton server-side implementation of a new "bundle-uri" command
to protocol v2. This will allow conforming clients to optionally seed
their initial clones or incremental fetches from URLs containing
"*.bundle" files created with "git bundle create".
This change only performs the basic boilerplate of advertising a new
protocol v2 capability. The new 'bundle-uri' capability allows a client
to request a list of bundles. Right now, the server only returns a flush
packet, which corresponds to an empty advertisement. The bundle.* config
namespace describes which key-value pairs will be communicated across
this interface in future updates.
The critical bit right now is that the new boolean
uploadPack.adverstiseBundleURIs config value signals whether or not this
capability should be advertised at all.
An earlier version of this patch [1] used a different transfer format
than the "key=value" pairs in the current implementation. The change was
made to unify the protocol v2 command with the bundle lists provided by
independent bundle servers. Further, the standard allows for the server
to advertise a URI that contains a bundle list. This allows users
automatically discovering bundle providers that are loosely associated
with the origin server, but without the origin server knowing exactly
which bundles are currently available.
[1] https://lore.kernel.org/git/RFC-patch-v2-01.13-2fc87ce092b-20220311T155841Z-avarab@gmail.com/
The very-deep headings needed to be modified to stop at level 4 due to
documentation build issues. These were not recognized in earlier builds
since the file was previously in the Documentation/technical/ directory
and was built in a different way. With its current location, the
heavily-nested details were causing build issues and they are now
replaced with a bulletted list of details.
Co-authored-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As in 7ff24785cb (leak tests: mark some misc tests as passing with
SANITIZE=leak, 2021-10-12) continue marking various miscellaneous
tests as passing when git is compiled with SANITIZE=leak. They'll now
be listed as running under the "GIT_TEST_PASSING_SANITIZE_LEAK=true"
test mode (the "linux-leaks" CI target).
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The v2 ls-refs command may receive extra arguments from the client, one
per pkt-line. The spec is pretty clear that the arguments must come from
a specified set, but we silently ignore any unknown entries. For a
well-behaved client this doesn't matter, but it makes testing and
debugging more confusing. Let's tighten this up to match the spec.
In theory this liberal behavior _could_ be useful for extending the
protocol. But:
- every other part of the protocol requires that the server first
indicate that it supports the argument; this includes the fetch and
object-info commands, plus the "unborn" capability added to ls-refs
itself
- it's not a very good extension mechanism anyway; without the server
advertising support, clients would have no idea if the argument was
silently ignored, or accepted and simply had no effect
So we're not really losing anything by tightening this.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our table of v2 "capabilities" contains everything we might tell the
client we support. But there are differences in how we expect the client
to respond. Some of the entries are true capabilities (i.e., we expect
the client to say "yes, I support this"), and some are ones we expect
them to send as commands (with "command=ls-refs" or similar).
When we receive a capability used as a command, we complain about that.
But when we receive a command used as a capability (e.g., just "ls-refs"
in a pkt-line by itself), we silently ignore it.
This isn't really hurting anything (clients shouldn't send it, and we'll
ignore it), but we can tighten up the protocol to match what we expect
to happen.
There are two new tests here. The first one checks a capability used as
a command, which already passes. The second tests a command as a
capability, which this patch fixes.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we see a line from the client like "command=ls-refs", we parse
everything after the equals sign as a capability, which we check against
our capabilities table. If we don't recognize the command (e.g.,
"command=foo"), we'll reject it.
But in parse_command(), we use the same get_capability() parser for
parsing non-command lines. So if we see "command=ls-refs=foo", we will
feed "ls-refs=foo" to get_capability(), which will say "OK, that's
ls-refs, with value 'foo'". But then we simply ignore the value
entirely.
The client is violating the spec here, which says:
command = PKT-LINE("command=" key LF)
key = 1*(ALPHA | DIGIT | "-_")
I.e., the key is not even allowed to have an equals sign in it. Whereas
a real non-command capability does allow a value:
capability = PKT-LINE(key[=value] LF)
So by reusing the same get_capability() parser, we are mixing up the
"key" and "capability" tokens. However, since that parser tells us
whether it saw an "=", we can still use it; we just need to reject any
input that produces a non-NULL value field.
The current behavior isn't really hurting anything (the client should
never send such a request, and if it does, we just ignore the "value"
part). But since it does violate the spec, let's tighten it up to
prevent any surprising behavior.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Because each "ref-prefix" capability from the client comes in its own
pkt-line, there's no limit to the number of them that a misbehaving
client may send. We read them all into a strvec, which means the client
can waste arbitrary amounts of our memory by just sending us "ref-prefix
foo" over and over.
One possible solution is to just drop the connection when the limit is
reached. If we set it high enough, then only misbehaving or malicious
clients would hit it. But "high enough" is vague, and it's unfriendly if
we guess wrong and a legitimate client hits this.
But we can do better. Since supporting the ref-prefix capability is
optional anyway, the client has to further cull the response based on
their own patterns. So we can simply ignore the patterns once we cross a
certain threshold. Note that we have to ignore _all_ patterns, not just
the ones past our limit (since otherwise we'd send too little data).
The limit here is fairly arbitrary, and probably much higher than anyone
would need in practice. It might be worth limiting it further, if only
because we check it linearly (so with "m" local refs and "n" patterns,
we do "m * n" string comparisons). But if we care about optimizing this,
an even better solution may be a more advanced data structure anyway.
I didn't bother making the limit configurable, since it's so high and
since Git should behave correctly in either case. It wouldn't be too
hard to do, but it makes both the code and documentation more complex.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git push" learns to discover common ancestor with the receiving
end over protocol v2.
* jt/push-negotiation:
send-pack: support push negotiation
fetch: teach independent negotiation (no packfile)
fetch-pack: refactor command and capability write
fetch-pack: refactor add_haves()
fetch-pack: refactor process_acks()
Currently, the packfile negotiation step within a Git fetch cannot be
done independent of sending the packfile, even though there is at least
one application wherein this is useful. Therefore, make it possible for
this negotiation step to be done independently. A subsequent commit will
use this for one such application - push negotiation.
This feature is for protocol v2 only. (An implementation for protocol v0
would require a separate implementation in the fetch, transport, and
transport helper code.)
In the protocol, the main hindrance towards independent negotiation is
that the server can unilaterally decide to send the packfile. This is
solved by a "wait-for-done" argument: the server will then wait for the
client to say "done". In practice, the client will never say it; instead
it will cease requests once it is satisfied.
In the client, the main change lies in the transport and transport
helper code. fetch_refs_via_pack() performs everything needed - protocol
version and capability checks, and the negotiation itself.
There are 2 code paths that do not go through fetch_refs_via_pack() that
needed to be individually excluded: the bundle transport (excluded
through requiring smart_options, which the bundle transport doesn't
support) and transport helpers that do not support takeover. If or when
we support independent negotiation for protocol v0, we will need to
modify these 2 code paths to support it. But for now, report failure if
independent negotiation is requested in these cases.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Sometimes it is useful to get information of an object without having to
download it completely.
Add the "object-info" capability that lets the client ask for
object-related information with their full hexadecimal object names.
Only sizes are returned for now.
Signed-off-by: Bruno Albuquerque <bga@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git clone" tries to locally check out the branch pointed at by
HEAD of the remote repository after it is done, but the protocol
did not convey the information necessary to do so when copying an
empty repository. The protocol v2 learned how to do so.
* jt/clone-unborn-head:
clone: respect remote unborn HEAD
connect, transport: encapsulate arg in struct
ls-refs: report unborn targets of symrefs
When cloning, we choose the default branch based on the remote HEAD.
But if there is no remote HEAD reported (which could happen if the
target of the remote HEAD is unborn), we'll fall back to using our local
init.defaultBranch. Traditionally this hasn't been a big deal, because
most repos used "master" as the default. But these days it is likely to
cause confusion if the server and client implementations choose
different values (e.g., if the remote started with "main", we may choose
"master" locally, create commits there, and then the user is surprised
when they push to "master" and not "main").
To solve this, the remote needs to communicate the target of the HEAD
symref, even if it is unborn, and "git clone" needs to use this
information.
Currently, symrefs that have unborn targets (such as in this case) are
not communicated by the protocol. Teach Git to advertise and support the
"unborn" feature in "ls-refs" (by default, this is advertised, but
server administrators may turn this off through the lsrefs.unborn
config). This feature indicates that "ls-refs" supports the "unborn"
argument; when it is specified, "ls-refs" will send the HEAD symref with
the name of its unborn target.
This change is only for protocol v2. A similar change for protocol v0
would require independent protocol design (there being no analogous
position to signal support for "unborn") and client-side plumbing of the
data required, so the scope of this patch set is limited to protocol v2.
The client side will be updated to use this in a subsequent commit.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This trick was performed via
$ (cd t &&
sed -i -e 's/master/main/g' -e 's/MASTER/MAIN/g' \
-e 's/Master/Main/g' -- t5[6-9]*.sh)
This allows us to define `GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main`
for those tests.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In addition to the manual adjustment to let the `linux-gcc` CI job run
the test suite with `master` and then with `main`, this patch makes sure
that GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME is set in all test scripts
that currently rely on the initial branch name being `master by default.
To determine which test scripts to mark up, the first step was to
force-set the default branch name to `master` in
- all test scripts that contain the keyword `master`,
- t4211, which expects `t/t4211/history.export` with a hard-coded ref to
initialize the default branch,
- t5560 because it sources `t/t556x_common` which uses `master`,
- t8002 and t8012 because both source `t/annotate-tests.sh` which also
uses `master`)
This trick was performed by this command:
$ sed -i '/^ *\. \.\/\(test-lib\|lib-\(bash\|cvs\|git-svn\)\|gitweb-lib\)\.sh$/i\
GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master\
export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME\
' $(git grep -l master t/t[0-9]*.sh) \
t/t4211*.sh t/t5560*.sh t/t8002*.sh t/t8012*.sh
After that, careful, manual inspection revealed that some of the test
scripts containing the needle `master` do not actually rely on a
specific default branch name: either they mention `master` only in a
comment, or they initialize that branch specificially, or they do not
actually refer to the current default branch. Therefore, the
aforementioned modification was undone in those test scripts thusly:
$ git checkout HEAD -- \
t/t0027-auto-crlf.sh t/t0060-path-utils.sh \
t/t1011-read-tree-sparse-checkout.sh \
t/t1305-config-include.sh t/t1309-early-config.sh \
t/t1402-check-ref-format.sh t/t1450-fsck.sh \
t/t2024-checkout-dwim.sh \
t/t2106-update-index-assume-unchanged.sh \
t/t3040-subprojects-basic.sh t/t3301-notes.sh \
t/t3308-notes-merge.sh t/t3423-rebase-reword.sh \
t/t3436-rebase-more-options.sh \
t/t4015-diff-whitespace.sh t/t4257-am-interactive.sh \
t/t5323-pack-redundant.sh t/t5401-update-hooks.sh \
t/t5511-refspec.sh t/t5526-fetch-submodules.sh \
t/t5529-push-errors.sh t/t5530-upload-pack-error.sh \
t/t5548-push-porcelain.sh \
t/t5552-skipping-fetch-negotiator.sh \
t/t5572-pull-submodule.sh t/t5608-clone-2gb.sh \
t/t5614-clone-submodules-shallow.sh \
t/t7508-status.sh t/t7606-merge-custom.sh \
t/t9302-fast-import-unpack-limit.sh
We excluded one set of test scripts in these commands, though: the range
of `git p4` tests. The reason? `git p4` stores the (foreign) remote
branch in the branch called `p4/master`, which is obviously not the
default branch. Manual analysis revealed that only five of these tests
actually require a specific default branch name to pass; They were
modified thusly:
$ sed -i '/^ *\. \.\/lib-git-p4\.sh$/i\
GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master\
export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME\
' t/t980[0167]*.sh t/t9811*.sh
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to communicate the protocol supported by the server side, add
support for advertising the object-format capability. We check that the
client side sends us an identical algorithm if it sends us its own
object-format capability, and assume it speaks SHA-1 if not.
In the test, when we're using an algorithm other than SHA-1, we need to
specify the algorithm in use so we don't get a failure with an "unknown
format" message. Add a test that we handle a mismatched algorithm.
Remove the test_oid_init call since it's no longer necessary.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `git serve` built-in was introduced in ed10cb952d (serve:
introduce git-serve, 2018-03-15) as a backend to serve Git protocol v2,
probably originally intended to be spawned by `git upload-pack`.
However, in the version that the protocol v2 patches made it into core
Git, `git upload-pack` calls the `serve()` function directly instead of
spawning `git serve`; The only reason in life for `git serve` to survive
as a built-in command is to provide a way to test the protocol v2
functionality.
Meaning that it does not even have to be a built-in that is installed
with end-user facing Git installations, but it can be a test helper
instead.
Let's make it so.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Define a GIT_TEST_SIDEBAND_ALL environment variable meant to be used
from tests. When set to true, this overrides uploadpack.allowsidebandall
to true, allowing the entire test suite to be run as if this
configuration is in place for all repositories.
As of this patch, all tests pass whether GIT_TEST_SIDEBAND_ALL is unset
or set to 1.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Various test scripts have been updated for style and also correct
handling of exit status of various commands.
* md/test-cleanup:
tests: order arguments to git-rev-list properly
t9109: don't swallow Git errors upstream of pipes
tests: don't swallow Git errors upstream of pipes
t/*: fix ordering of expected/observed arguments
tests: standardize pipe placement
Documentation: add shell guidelines
t/README: reformat Do, Don't, Keep in mind lists
Fix various places where the ordering was obviously wrong, meaning it
was easy to find with grep.
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Transfer protocol v2 learned to support the partial clone.
* jt/partial-clone-proto-v2:
{fetch,upload}-pack: support filter in protocol v2
upload-pack: read config when serving protocol v2
upload-pack: fix error message typo
Fix a typo in an error message.
Also, this line was introduced in 3145ea957d ("upload-pack: introduce
fetch server command", 2018-03-15), which did not contain a test for the
case which causes this error to be printed, so introduce a test.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce the "server-option" capability to protocol version 2. This
enables future clients the ability to send server specific options in
command requests when using protocol version 2.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When communicating with a v2 server, perform a fetch by requesting the
'fetch' command.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce the ls-refs server command. In protocol v2, the ls-refs
command is used to request the ref advertisement from the server. Since
it is a command which can be requested (as opposed to mandatory in v1),
a client can sent a number of parameters in its request to limit the ref
advertisement based on provided ref-prefixes.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce git-serve, the base server for protocol version 2.
Protocol version 2 is intended to be a replacement for Git's current
wire protocol. The intention is that it will be a simpler, less
wasteful protocol which can evolve over time.
Protocol version 2 improves upon version 1 by eliminating the initial
ref advertisement. In its place a server will export a list of
capabilities and commands which it supports in a capability
advertisement. A client can then request that a particular command be
executed by providing a number of capabilities and command specific
parameters. At the completion of a command, a client can request that
another command be executed or can terminate the connection by sending a
flush packet.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
