Whenever GIT_CURL_VERBOSE is set, teach Git to behave as if
GIT_TRACE_CURL=1 and GIT_TRACE_CURL_NO_DATA=1 is set, instead of setting
CURLOPT_VERBOSE.
This is to prevent inadvertent revelation of sensitive data. In
particular, GIT_CURL_VERBOSE redacts neither the "Authorization" header
nor any cookies specified by GIT_REDACT_COOKIES.
Unifying the tracing mechanism also has the future benefit that any
improvements to the tracing mechanism will benefit both users of
GIT_CURL_VERBOSE and GIT_TRACE_CURL, and we do not need to remember to
implement any improvement twice.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Verify that when GIT_TRACE_CURL is set, Git prints out "Authorization:
Basic <redacted>" instead of the base64-encoded authorization details.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since 8cbeba0632 (tests: define GIT_TEST_PROTOCOL_VERSION,
2019-02-25), it has been possible to run tests with a newer protocol
version by setting the GIT_TEST_PROTOCOL_VERSION envvar to a version
number. Tests that assume protocol v0 handle this by explicitly
setting
GIT_TEST_PROTOCOL_VERSION=
or similar constructs like 'test -z "$GIT_TEST_PROTOCOL_VERSION" ||
return 0' to declare that they only handle the default (v0) protocol.
The emphasis there is a bit off: it would be clearer to specify
GIT_TEST_PROTOCOL_VERSION=0 to inform the reader that these tests are
specifically testing and relying on details of protocol v0. Do so.
This way, a reader does not need to know what the default protocol
version is, and the tests can continue to work when the default
protocol version used by Git advances past v0.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When run using GIT_TEST_PROTOCOL_VERSION=2, a test in t5551 fails
because 4 POSTs (probe, ls-refs, probe, fetch) are sent instead of 2
(probe, fetch).
One way to resolve this would be to relax the condition (from "= 2" to
greater than 1, say), but upon further inspection, the test probably
shouldn't be counting the number of POSTs. This test states that large
requests are split across POSTs, but this is not correct; the main
change is that chunked transfer encoding is used, but the request is
still contained within one POST. (The test coincidentally works because
Git indeed sends 2 POSTs in the case of a large request, but that is
because, as stated above, the first POST is a probing RPC - see
post_rpc() in remote-curl.c for more information.)
Therefore, instead of counting POSTs, check that chunked transfer
encoding is used. This also has the desirable side effect of passing
with GIT_TEST_PROTOCOL_VERSION=2.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Acked-by: Derrick Stolee <dstolee@microsoft.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The two tests 'invalid Content-Type rejected' and 'server-side error
detected' in 't5551-http-fetch-smart.sh' use "plain" 'grep' to check
that 'git clone' failed with the expected error message, but the
messages they are checking are translated, and, consequently, these
tests fail when the test script is run with GIT_TEST_GETTEXT_POISON
enabled.
Use 'test_i18ngrep' instead.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test framework update to more robustly clean up leftover files and
processes after tests are done.
* sg/test-atexit:
t9811-git-p4-label-import: fix pipeline negation
git p4 test: disable '-x' tracing in the p4d watchdog loop
git p4 test: simplify timeout handling
git p4 test: clean up the p4d cleanup functions
git p4 test: use 'test_atexit' to kill p4d and the watchdog process
t0301-credential-cache: use 'test_atexit' to stop the credentials helper
tests: use 'test_atexit' to stop httpd
git-daemon: use 'test_atexit` to stop 'git-daemon'
test-lib: introduce 'test_atexit'
t/lib-git-daemon: make sure to kill the 'git-daemon' process
test-lib: fix interrupt handling with 'dash' and '--verbose-log -x'
Help developers by making it easier to run most of the tests under
different versions of over-the-wire protocols.
* jt/test-protocol-version:
t5552: compensate for v2 filtering ref adv.
tests: fix protocol version for overspecifications
t5700: only run with protocol version 1
t5512: compensate for v0 only sending HEAD symrefs
t5503: fix overspecification of trace expectation
tests: always test fetch of unreachable with v0
t5601: check ssh command only with protocol v0
tests: define GIT_TEST_PROTOCOL_VERSION
When using protocol v0, upload-pack over HTTP permits a "half-auth"
configuration in which, at the web server layer, the info/refs path is
not protected by authentication but the git-upload-pack path is, so that
a user can perform fetches that do not download any objects without
authentication, but still needs authentication to download objects.
But protocol v2 does not support this, because both ref and pack are
obtained from the git-upload-pack path.
Mark the test verifying this behavior as protocol v0-only, with a
description of what needs to be done to make v2 support this.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use 'test_atexit' to run cleanup commands to stop httpd at the end of
the test script or upon interrupt or failure, as it is shorter,
simpler, and more robust than registering such cleanup commands in the
trap on EXIT in the test scripts.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These tests are also marked with a NEEDSWORK comment.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some tests check that fetching an unreachable object fails, but protocol
v2 allows such fetches. Unset GIT_TEST_PROTOCOL_VERSION so that these
tests are always run using protocol v0.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Define a GIT_TEST_PROTOCOL_VERSION environment variable meant to be used
from tests. When set, this ensures protocol.version is at least the
given value, 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_PROTOCOL_VERSION is
unset or set to 0. Some tests fail when GIT_TEST_PROTOCOL_VERSION is set
to 1 or 2, but this will be dealt with in subsequent patches.
This is based on work by Ævar Arnfjörð Bjarmason.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a smart HTTP server sends an error message via pkt-line, we detect
the error due to using PACKET_READ_DIE_ON_ERR_PACKET. This case was
added by 2d103c31c2 (pack-protocol.txt: accept error packets in any
context, 2018-12-29), but not covered by tests.
Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Over some transports, fetching objects with an exact commit object
name can be done without first seeing the ref advertisements. The
code has been optimized to exploit this.
* jt/avoid-ls-refs:
fetch: do not list refs if fetching only hashes
transport: list refs before fetch if necessary
transport: do not list refs if possible
transport: allow skipping of ref listing
If only hash literals are given on a "git fetch" command-line, tag
following is not requested, and the fetch is done using protocol v2, a
list of refs is not required from the remote. Therefore, optimize by
invoking transport_get_remote_refs() only if we need the refs.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In t5551 we check that we save cookies correctly to a file when
http.cookiefile and http.savecookies are set. To do so we create an
expect file that expects the cookies in a certain order.
However after e2ef8d6fa ("cookies: support creation-time attribute for
cookies", 2018-08-28) in curl.git (released in curl 7.61.1) that order
changed.
We document the file format as "Netscape/Mozilla cookie file
format (see curl(1))", so any format produced by libcurl should be
fine here. Sort the files, to be agnostic to the order of the
cookies, and make the test pass with both curl versions > 7.61.1 and
earlier curl versions.
Reported-by: Todd Zullinger <tmz@pobox.com>
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move setup code inside test_expect blocks, to catch unexpected
failures in the setup steps, and bring the test scripts in line with
our modern test style.
Suggested-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git fetch" sometimes failed to update the remote-tracking refs,
which has been corrected.
* jt/connectivity-check-after-unshallow:
fetch-pack: unify ref in and out param
httpd tests saw occasional breakage due to the way its access log
gets inspected by the tests, which has been updated to make them
less flaky.
* sg/httpd-test-unflake:
t/lib-httpd: avoid occasional failures when checking access.log
t/lib-httpd: add the strip_access_log() helper function
t5541: clean up truncating access log
When a user fetches:
- at least one up-to-date ref and at least one non-up-to-date ref,
- using HTTP with protocol v0 (or something else that uses the fetch
command of a remote helper)
some refs might not be updated after the fetch.
This bug was introduced in commit 989b8c4452 ("fetch-pack: put shallow
info in output parameter", 2018-06-28) which allowed transports to
report the refs that they have fetched in a new out-parameter
"fetched_refs". If they do so, transport_fetch_refs() makes this
information available to its caller.
Users of "fetched_refs" rely on the following 3 properties:
(1) it is the complete list of refs that was passed to
transport_fetch_refs(),
(2) it has shallow information (REF_STATUS_REJECT_SHALLOW set if
relevant), and
(3) it has updated OIDs if ref-in-want was used (introduced after
989b8c4452).
In an effort to satisfy (1), whenever transport_fetch_refs()
filters the refs sent to the transport, it re-adds the filtered refs to
whatever the transport supplies before returning it to the user.
However, the implementation in 989b8c4452 unconditionally re-adds the
filtered refs without checking if the transport refrained from reporting
anything in "fetched_refs" (which it is allowed to do), resulting in an
incomplete list, no longer satisfying (1).
An earlier effort to resolve this [1] solved the issue by readding the
filtered refs only if the transport did not refrain from reporting in
"fetched_refs", but after further discussion, it seems that the better
solution is to revert the API change that introduced "fetched_refs".
This API change was first suggested as part of a ref-in-want
implementation that allowed for ref patterns and, thus, there could be
drastic differences between the input refs and the refs actually fetched
[2]; we eventually decided to only allow exact ref names, but this API
change remained even though its necessity was decreased.
Therefore, revert this API change by reverting commit 989b8c4452, and
make receive_wanted_refs() update the OIDs in the sought array (like how
update_shallow() updates shallow information in the sought array)
instead. A test is also included to show that the user-visible bug
discussed at the beginning of this commit message no longer exists.
[1] https://public-inbox.org/git/20180801171806.GA122458@google.com/
[2] https://public-inbox.org/git/86a128c5fb710a41791e7183207c4d64889f9307.1485381677.git.jonathantanmy@google.com/
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The last test of 't5561-http-backend.sh', 'server request log matches
test results' may fail occasionally, because the order of entries in
Apache's access log doesn't match the order of requests sent in the
previous tests, although all the right requests are there. I saw it
fail on Travis CI five times in the span of about half a year, when
the order of two subsequent requests was flipped, and could trigger
the failure with a modified Git. However, I was unable to trigger it
with stock Git on my machine. Three tests in
't5541-http-push-smart.sh' and 't5551-http-fetch-smart.sh' check
requests in the log the same way, so they might be prone to a similar
occasional failure as well.
When a test sends a HTTP request, it can continue execution after
'git-http-backend' fulfilled that request, but Apache writes the
corresponding access log entry only after 'git-http-backend' exited.
Some time inevitably passes between fulfilling the request and writing
the log entry, and, under unfavourable circumstances, enough time
might pass for the subsequent request to be sent and fulfilled by a
different Apache thread or process, and then Apache writes access log
entries racily.
This effect can be exacerbated by adding a bit of variable delay after
the request is fulfilled but before 'git-http-backend' exits, e.g.
like this:
diff --git a/http-backend.c b/http-backend.c
index f3dc218b2..bbf4c125b 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -709,5 +709,7 @@ int cmd_main(int argc, const char **argv)
max_request_buffer);
cmd->imp(&hdr, cmd_arg);
+ if (getpid() % 2)
+ sleep(1);
return 0;
}
This delay considerably increases the chances of log entries being
written out of order, and in turn makes t5561's last test fail almost
every time. Alas, it doesn't seem to be enough to trigger a similar
failure in t5541 and t5551.
So, since we can't just rely on the order of access log entries always
corresponding the order of requests, make checking the access log more
deterministic by sorting (simply lexicographically) both the stripped
access log entries and the expected entries before the comparison with
'test_cmp'. This way the order of log entries won't matter and
occasional out-of-order entries won't trigger a test failure, but the
comparison will still notice any unexpected or missing log entries.
OTOH, this sorting will make it harder to identify from which test an
unexpected log entry came from or which test's request went missing.
Therefore, in case of an error include the comparison of the unsorted
log enries in the test output as well.
And since all this should be performed in four tests in three test
scripts, put this into a new helper function 'check_access_log' in
't/lib-httpd.sh'.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Four tests in three httpd-related test scripts check the contents of
Apache's 'access.log', and they all do so by running 'sed' with the
exact same script consisting of four s/// commands to strip
uninteresting log fields and to vertically align the requested URLs.
Extract this into a common helper function 'strip_access_log' in
'lib-httpd.sh', and use it in all of those tests.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Configure curl to accept all encodings which curl supports instead of
only accepting gzip responses.
This fixes an issue when using an installation of curl which is built
without the "zlib" feature. Since aa90b9697 (Enable info/refs gzip
decompression in HTTP client, 2012-09-19) we end up requesting "gzip"
encoding anyway despite libcurl not being able to decode it. Worse,
instead of getting a clear error message indicating so, we end up
falling back to "dumb" http, producing a confusing and difficult to
debug result.
Since curl doesn't do any checking to verify that it supports the a
requested encoding, instead set the curl option `CURLOPT_ENCODING` with
an empty string indicating that curl should send an "Accept-Encoding"
header containing only the encodings supported by curl.
Reported-by: Anton Golubev <anton.golubev@gmail.com>
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
GIT_TRACE_CURL provides a way to debug what is being sent and received
over HTTP, with automatic redaction of sensitive information. But it
also logs data transmissions, which significantly increases the log file
size, sometimes unnecessarily. Add an option "GIT_TRACE_CURL_NO_DATA" to
allow the user to omit such data transmissions.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When using GIT_TRACE_CURL, Git already redacts the "Authorization:" and
"Proxy-Authorization:" HTTP headers. Extend this redaction to a
user-specified list of cookies, specified through the
"GIT_REDACT_COOKIES" environment variable.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the http server gives an incomplete response to a smart-http
rpc call, it could lead to client waiting for a full response that
will never come. Teach the client side to notice this condition
and abort the transfer.
An improvement counterproposal has failed.
cf. <20161114194049.mktpsvgdhex2f4zv@sigill.intra.peff.net>
* dt/smart-http-detect-server-going-away:
upload-pack: optionally allow fetching any sha1
remote-curl: don't hang when a server dies before any output
Transport with dumb http can be fooled into following foreign URLs
that the end user does not intend to, especially with the server
side redirects and http-alternates mechanism, which can lead to
security issues. Tighten the redirection and make it more obvious
to the end user when it happens.
* jk/http-walker-limit-redirect-2.9:
http: treat http-alternates like redirects
http: make redirects more obvious
remote-curl: rename shadowed options variable
http: always update the base URL for redirects
http: simplify update_url_from_redirect
If a malicious server redirects the initial ref
advertisement, it may be able to leak sha1s from other,
unrelated servers that the client has access to. For
example, imagine that Alice is a git user, she has access to
a private repository on a server hosted by Bob, and Mallory
runs a malicious server and wants to find out about Bob's
private repository.
Mallory asks Alice to clone an unrelated repository from her
over HTTP. When Alice's client contacts Mallory's server for
the initial ref advertisement, the server issues an HTTP
redirect for Bob's server. Alice contacts Bob's server and
gets the ref advertisement for the private repository. If
there is anything to fetch, she then follows up by asking
the server for one or more sha1 objects. But who is the
server?
If it is still Mallory's server, then Alice will leak the
existence of those sha1s to her.
Since commit c93c92f30 (http: update base URLs when we see
redirects, 2013-09-28), the client usually rewrites the base
URL such that all further requests will go to Bob's server.
But this is done by textually matching the URL. If we were
originally looking for "http://mallory/repo.git/info/refs",
and we got pointed at "http://bob/other.git/info/refs", then
we know that the right root is "http://bob/other.git".
If the redirect appears to change more than just the root,
we punt and continue to use the original server. E.g.,
imagine the redirect adds a URL component that Bob's server
will ignore, like "http://bob/other.git/info/refs?dummy=1".
We can solve this by aborting in this case rather than
silently continuing to use Mallory's server. In addition to
protecting from sha1 leakage, it's arguably safer and more
sane to refuse a confusing redirect like that in general.
For example, part of the motivation in c93c92f30 is
avoiding accidentally sending credentials over clear http,
just to get a response that says "try again over https". So
even in a non-malicious case, we'd prefer to err on the side
of caution.
The downside is that it's possible this will break a
legitimate but complicated server-side redirection scheme.
The setup given in the newly added test does work, but it's
convoluted enough that we don't need to care about it. A
more plausible case would be a server which redirects a
request for "info/refs?service=git-upload-pack" to just
"info/refs" (because it does not do smart HTTP, and for some
reason really dislikes query parameters). Right now we
would transparently downgrade to dumb-http, but with this
patch, we'd complain (and the user would have to set
GIT_SMART_HTTP=0 to fetch).
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It seems a little silly to do a reachabilty check in the case where we
trust the user to access absolutely everything in the repository.
Also, it's racy in a distributed system -- perhaps one server
advertises a ref, but another has since had a force-push to that ref,
and perhaps the two HTTP requests end up directed to these different
servers.
Signed-off-by: David Turner <dturner@twosigma.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the event that a HTTP server closes the connection after giving a
200 but before giving any packets, we don't want to hang forever
waiting for a response that will never come. Instead, we should die
immediately.
One case where this happens is when attempting to fetch a dangling
object by its object name. In this case, the server dies before
sending any data. Prior to this patch, fetch-pack would wait for
data from the server, and remote-curl would wait for fetch-pack,
causing a deadlock.
Despite this patch, there is other possible malformed input that could
cause the same deadlock (e.g. a half-finished pktline, or a pktline but
no trailing flush). There are a few possible solutions to this:
1. Allowing remote-curl to tell fetch-pack about the EOF (so that
fetch-pack could know that no more data is coming until it says
something else). This is tricky because an out-of-band signal would
be required, or the http response would have to be re-framed inside
another layer of pkt-line or something.
2. Make remote-curl understand some of the protocol. It turns out
that in addition to understanding pkt-line, it would need to watch for
ack/nak. This is somewhat fragile, as information about the protocol
would end up in two places. Also, pkt-lines which are already at the
length limit would need special handling.
Both of these solutions would require a fair amount of work, whereas
this hack is easy and solves at least some of the problem.
Still to do: it would be good to give a better error message
than "fatal: The remote end hung up unexpectedly".
Signed-off-by: David Turner <dturner@twosigma.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use the new GIT_TRACE_CURL environment variable instead
of the deprecated GIT_CURL_VERBOSE.
Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To support this developer's use case of allowing build agents token-based
access to private repositories, we introduced the http.extraheader
feature, allowing extra HTTP headers to be sent along with every HTTP
request.
This patch verifies that we can configure these extra HTTP headers via the
command-line for use with `git submodule update`, too. Example: git -c
http.extraheader="Secret: Sauce" submodule update --init
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To test that extra HTTP headers are passed correctly, t5551 verifies that
a fetch succeeds when two required headers are passed, and that the fetch
does not succeed when those headers are not passed.
However, this test would also succeed if the configuration required only
one header. As Apache's configuration is notoriously tricky (this
developer frequently requires StackOverflow's help to understand Apache's
documentation), especially when still supporting the 2.2 line, let's just
really make sure that the test verifies what we want it to verify.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We introduce a way to send custom HTTP headers with all requests.
This allows us, for example, to send an extra token from build agents
for temporary access to private repositories. (This is the use case that
triggered this patch.)
This feature can be used like this:
git -c http.extraheader='Secret: sssh!' fetch $URL $REF
Note that `curl_easy_setopt(..., CURLOPT_HTTPHEADER, ...)` takes only
a single list, overriding any previous call. This means we have to
collect _all_ of the headers we want to use into a single list, and
feed it to cURL in one shot. Since we already unconditionally set a
"pragma" header when initializing the curl handles, we can add our new
headers to that list.
For callers which override the default header list (like probe_rpc),
we provide `http_copy_default_headers()` so they can do the same
trick.
Big thanks to Jeff King and Junio Hamano for their outstanding help and
patient reviews.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Communication between the HTTP server and http_backend process can
lead to a dead-lock when relaying a large ref negotiation request.
Diagnose the situation better, and mitigate it by reading such a
request first into core (to a reasonable limit).
* jk/http-backend-deadlock:
http-backend: spool ref negotiation requests to buffer
t5551: factor out tag creation
http-backend: fix die recursion with custom handler
* jk/http-backend-deadlock-2.3:
http-backend: spool ref negotiation requests to buffer
t5551: factor out tag creation
http-backend: fix die recursion with custom handler
* jk/http-backend-deadlock-2.2:
http-backend: spool ref negotiation requests to buffer
t5551: factor out tag creation
http-backend: fix die recursion with custom handler
When http-backend spawns "upload-pack" to do ref
negotiation, it streams the http request body to
upload-pack, who then streams the http response back to the
client as it reads. In theory, git can go full-duplex; the
client can consume our response while it is still sending
the request. In practice, however, HTTP is a half-duplex
protocol. Even if our client is ready to read and write
simultaneously, we may have other HTTP infrastructure in the
way, including the webserver that spawns our CGI, or any
intermediate proxies.
In at least one documented case[1], this leads to deadlock
when trying a fetch over http. What happens is basically:
1. Apache proxies the request to the CGI, http-backend.
2. http-backend gzip-inflates the data and sends
the result to upload-pack.
3. upload-pack acts on the data and generates output over
the pipe back to Apache. Apache isn't reading because
it's busy writing (step 1).
This works fine most of the time, because the upload-pack
output ends up in a system pipe buffer, and Apache reads
it as soon as it finishes writing. But if both the request
and the response exceed the system pipe buffer size, then we
deadlock (Apache blocks writing to http-backend,
http-backend blocks writing to upload-pack, and upload-pack
blocks writing to Apache).
We need to break the deadlock by spooling either the input
or the output. In this case, it's ideal to spool the input,
because Apache does not start reading either stdout _or_
stderr until we have consumed all of the input. So until we
do so, we cannot even get an error message out to the
client.
The solution is fairly straight-forward: we read the request
body into an in-memory buffer in http-backend, freeing up
Apache, and then feed the data ourselves to upload-pack. But
there are a few important things to note:
1. We limit the in-memory buffer to prevent an obvious
denial-of-service attack. This is a new hard limit on
requests, but it's unlikely to come into play. The
default value is 10MB, which covers even the ridiculous
100,000-ref negotation in the included test (that
actually caps out just over 5MB). But it's configurable
on the off chance that you don't mind spending some
extra memory to make even ridiculous requests work.
2. We must take care only to buffer when we have to. For
pushes, the incoming packfile may be of arbitrary
size, and we should connect the input directly to
receive-pack. There's no deadlock problem here, though,
because we do not produce any output until the whole
packfile has been read.
For upload-pack's initial ref advertisement, we
similarly do not need to buffer. Even though we may
generate a lot of output, there is no request body at
all (i.e., it is a GET, not a POST).
[1] http://article.gmane.org/gmane.comp.version-control.git/269020
Test-adapted-from: Dennis Kaarsemaker <dennis@kaarsemaker.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test clean-up.
* jk/skip-http-tests-under-no-curl:
tests: skip dav http-push tests under NO_EXPAT=NoThanks
t/lib-httpd.sh: skip tests if NO_CURL is defined
One of our tests in t5551 creates a large number of tags,
and jumps through some hoops to do it efficiently. Let's
factor that out into a function so we can make other similar
tests.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we built git without curl, we can't actually test against
an http server. In fact, all of the test scripts which
include lib-httpd.sh already perform this check, with one
exception: t5540. For those scripts, this is a noop, and for
t5540, this is a bugfix (it used to fail when built with
NO_CURL, though it could go unnoticed if you had a stale
git-remote-https in your build directory).
Noticed-by: Junio C Hamano <junio@pobox.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
People often forget to chain the commands in their test together
with &&, leaving a failure from an earlier command in the test go
unnoticed. The new GIT_TEST_CHAIN_LINT mechanism allows you to
catch such a mistake more easily.
* jk/test-chain-lint: (36 commits)
t9001: drop save_confirm helper
t0020: use test_* helpers instead of hand-rolled messages
t: simplify loop exit-code status variables
t: fix some trivial cases of ignored exit codes in loops
t7701: fix ignored exit code inside loop
t3305: fix ignored exit code inside loop
t0020: fix ignored exit code inside loops
perf-lib: fix ignored exit code inside loop
t6039: fix broken && chain
t9158, t9161: fix broken &&-chain in git-svn tests
t9104: fix test for following larger parents
t4104: drop hand-rolled error reporting
t0005: fix broken &&-chains
t7004: fix embedded single-quotes
t0050: appease --chain-lint
t9001: use test_when_finished
t4117: use modern test_* helpers
t6034: use modern test_* helpers
t1301: use modern test_* helpers
t0020: use modern test_* helpers
...
Test fixes.
* jk/test-annoyances:
t5551: make EXPENSIVE test cheaper
t5541: move run_with_cmdline_limit to test-lib.sh
t: pass GIT_TRACE through Apache
t: redirect stderr GIT_TRACE to descriptor 4
t: translate SIGINT to an exit
These are tests which are missing a link in their &&-chain,
but during a setup phase. We may fail to notice failure in
commands that build the test environment, but these are
typically not expected to fail at all (but it's still good
to double-check that our test environment is what we
expect).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These are tests which are missing a link in their &&-chain,
but in a way that probably does not effect the outcome of
the test. Most of these are of the form:
some_cmd >actual
test_cmp expect actual
The main point of the test is to verify the output, and a
failure in some_cmd would probably be noticed by bogus
output. But it is good for the tests to also confirm that
"some_cmd" does not die unexpectedly after producing its
output.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These are tests which are missing a link in their &&-chain,
in a location which causes a significant portion of the test
to be missed (e.g., the test effectively does nothing, or
consists of a long string of actions and output comparisons,
and we throw away the exit code of at least one part of the
string).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We create 50,000 tags to check that we don't overflow the
command-line of fetch-pack. But by using run_with_cmdline_limit,
we can get the same effect with a much smaller number of
tags. This makes the test fast enough that we can drop the
EXPENSIVE prereq, which means people will actually run it.
It was not documented to do so, but this test was also the
only test of a clone-over-http that requires multiple POSTs
during the conversation. We can continue to test that by
dropping http.postbuffer to its minimum size, and checking
that we get two POSTs.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When upload-pack advertises the refs (either for a normal,
non-stateless request, or for the initial contact in a
stateless one), we call for_each_ref with the send_ref
function as its callback. send_ref, in turn, calls
mark_our_ref, which checks whether the ref is hidden, and
sets OUR_REF or HIDDEN_REF on the object as appropriate. If
it is hidden, mark_our_ref also returns "1" to signal
send_ref that the ref should not be advertised.
If we are not advertising refs, (i.e., the follow-up
invocation by an http client to send its "want" lines), we
use mark_our_ref directly as a callback to for_each_ref. Its
marking does the right thing, but when it then returns "1"
to for_each_ref, the latter interprets this as an error and
stops iterating. As a result, we skip marking all of the
refs that come lexicographically after it. Any "want" lines
from the client asking for those objects will fail, as they
were not properly marked with OUR_REF.
To solve this, we introduce a wrapper callback around
mark_our_ref which always returns 0 (even if the ref is
hidden, we want to keep iterating). We also tweak the
signature of mark_our_ref to exclude unnecessary parameters
that were present only to conform to the callback interface.
This should make it less likely for somebody to accidentally
use it as a callback in the future.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
