packet_write() should be called packet_write_fmt() because it is a
printf-like function that takes a format string as first parameter.
packet_write_fmt() should be used for text strings only. Arbitrary
binary data should use a new packet_write() function that is introduced
in a subsequent patch.
Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Mark messages passed to die() in die_initial_contact().
Update test to reflect changes.
Signed-off-by: Vasco Almeida <vascomalmeida@sapo.pt>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When cloning an empty repository served by standard git, "git clone" produces
the following reassuring message:
$ git clone git://localhost/tmp/empty
Cloning into 'empty'...
warning: You appear to have cloned an empty repository.
Checking connectivity... done.
Meanwhile when cloning an empty repository served by JGit, the output is more
haphazard:
$ git clone git://localhost/tmp/empty
Cloning into 'empty'...
Checking connectivity... done.
warning: remote HEAD refers to nonexistent ref, unable to checkout.
This is a common command to run immediately after creating a remote repository
as preparation for adding content to populate it and pushing. The warning is
confusing and needlessly worrying.
The cause is that, since v3.1.0.201309270735-rc1~22 (Advertise capabilities
with no refs in upload service., 2013-08-08), JGit's ref advertisement includes
a ref named capabilities^{} to advertise its capabilities on, while git's ref
advertisement is empty in this case. This allows the client to learn about the
server's capabilities and is needed, for example, for fetch-by-sha1 to work
when no refs are advertised.
This also affects "ls-remote". For example, against an empty repository served
by JGit:
$ git ls-remote git://localhost/tmp/empty
0000000000000000000000000000000000000000 capabilities^{}
Git advertises the same capabilities^{} ref in its ref advertisement for push
but since it never did so for fetch, the client didn't need to handle this
case. Handle it.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A server hanging up immediately to mark access being denied does not
send any .have refs, shallow lines, or anything else before hanging
up. If the server has sent anything, then the hangup is unexpected.
That is, if the server hangs up after a shallow line but before sending
any refs, then git should tell me so:
fatal: The remote end hung up upon initial contact
instead of suggesting an access control problem:
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
Noticed while examining this code. This case isn't likely to come up
in practice but tightening the check makes the code easier to read and
manipulate.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Similar to $GIT_ASKPASS or $GIT_PROXY_COMMAND, we also read from
config file first then fall back to $GIT_SSH_COMMAND.
This is useful for selecting different private keys targetting the
same host (e.g. github)
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some people argue that these were silly from the beginning (see
http://thread.gmane.org/gmane.comp.version-control.git/285590/focus=285601
for example), but we have to support them for compatibility.
That doesn't mean we have to show them in the documentation. These
were already left out of the main list, but a reference in the main
manpage was left, so remove that.
Also add a note to discourage their use if anybody goes looking for them
in the source code.
Signed-off-by: Carlos Martín Nieto <cmn@dwim.me>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Sometimes it is necessary to force IPv4-only or IPv6-only operation
on networks where name lookups may return a non-routable address and
stall remote operations.
The ssh(1) command has an equivalent switches which we may pass when
we run them. There may be old ssh(1) implementations out there
which do not support these switches; they should report the
appropriate error in that case.
rsync support is untouched for now since it is deprecated and
scheduled to be removed.
Signed-off-by: Eric Wong <normalperson@yhbt.net>
Reviewed-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Replace an unsigned char array with struct object_id and express several
hard-coded constants in terms of GIT_SHA1_HEXSZ.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
Use struct object_id in three fields in struct ref and convert all the
necessary places that use it.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
We sometimes sprintf into fixed-size buffers when we know
that the buffer is large enough to fit the input (either
because it's a constant, or because it's numeric input that
is bounded in size). Likewise with strcpy of constant
strings.
However, these sites make it hard to audit sprintf and
strcpy calls for buffer overflows, as a reader has to
cross-reference the size of the array with the input. Let's
use xsnprintf instead, which communicates to a reader that
we don't expect this to overflow (and catches the mistake in
case we do).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we are cloning an untrusted remote repository into a
sandbox, we may also want to fetch remote submodules in
order to get the complete view as intended by the other
side. However, that opens us up to attacks where a malicious
user gets us to clone something they would not otherwise
have access to (this is not necessarily a problem by itself,
but we may then act on the cloned contents in a way that
exposes them to the attacker).
Ideally such a setup would sandbox git entirely away from
high-value items, but this is not always practical or easy
to set up (e.g., OS network controls may block multiple
protocols, and we would want to enable some but not others).
We can help this case by providing a way to restrict
particular protocols. We use a whitelist in the environment.
This is more annoying to set up than a blacklist, but
defaults to safety if the set of protocols git supports
grows). If no whitelist is specified, we continue to default
to allowing all protocols (this is an "unsafe" default, but
since the minority of users will want this sandboxing
effect, it is the only sensible one).
A note on the tests: ideally these would all be in a single
test file, but the git-daemon and httpd test infrastructure
is an all-or-nothing proposition rather than a test-by-test
prerequisite. By putting them all together, we would be
unable to test the file-local code on machines without
apache.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When executing user-specified programs, we generally always
want to use a shell, for flexibility and consistency. One
big exception is executing $GIT_SSH, which for historical
reasons must not use a shell.
Once upon a time the logic in git_connect looked like:
if (protocol == PROTO_SSH) {
... setup ssh ...
} else {
... setup local connection ...
conn->use_shell = 1;
}
But over time the PROTO_SSH block has grown, and the "local"
block has shrunk so that it contains only conn->use_shell;
it's easy to miss at the end of the large block. Moreover,
PROTO_SSH now also sometimes sets use_shell, when the new
GIT_SSH_COMMAND is used.
Let's just set conn->use_shell when we're setting up the "conn"
struct, and unset it (with a comment) in the historical GIT_SSH
case. This will make the flow easier to follow.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we "switch" to another local repository to run the server
side of a fetch or push, we must clear the variables in
local_repo_env so that our local $GIT_DIR, etc, do not
pollute the upload-pack or receive-pack that is executing in
the "remote" repository.
We have never done so for ssh connections. For the most
part, nobody has noticed because ssh will not pass unknown
environment variables by default. However, it is not out of
the question for a user to configure ssh to pass along GIT_*
variables using SendEnv/AcceptEnv.
We can demonstrate the problem by using "git -c" on a local
command and seeing its impact on a remote repository. This
config ends up in $GIT_CONFIG_PARAMETERS. In the local case,
the config has no impact, but in the ssh transport, it does
(our test script has a fake ssh that passes through all
environment variables; this isn't normal, but does simulate
one possible setup).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git_connect function has code to handle plink and tortoiseplink
specially, as they require different command line arguments from
OpenSSH (-P instead of -p for ports; tortoiseplink additionally requires
-batch). However, the match was done by checking for "plink" anywhere
in the string, which led to a GIT_SSH value containing "uplink" being
treated as an invocation of putty's plink.
Improve the check by looking for "plink" or "tortoiseplink" (or those
names suffixed with ".exe") only in the final component of the path.
This has the downside that a program such as "plink-0.63" would no
longer be recognized, but the increased robustness is likely worth it.
Add tests to cover these cases to avoid regressions.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code path used in git_connect pushed the majority of the SSH
connection code into an else block, even though the if block returns.
Simplify the code by eliminating the else block, as it is unneeded.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Ignore an extra ':' at the end of the hostname in URL's like
"ssh://example.com:/path/to/repo"
The colon is meant to separate a port number from the hostname.
If the port is empty, the colon should be ignored, see RFC 3986.
It had been working for URLs with ssh:// scheme, but was unintentionally
broken in 86ceb3, "allow ssh://user@[2001:db8::1]/repo.git"
Reported-by: Reid Woodbury Jr. <reidw@rawsound.com>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When git_connect() is called to see how the URL is parsed for
debugging purposes with CONNECT_DIAG_URL set, the variable conn is
leaked. At this point in the codeflow, it only has its memory and
no other resource is associated with it, so it is sufficient to
clean it up by just freeing it.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The URL for ssh may have include a username before the hostname,
like ssh://user@host/repo.
When literal IPV6 addresses are used together with a username,
the substring "user@[::1]" must be converted into "user@::1".
Make that conversion visible for the user, and write userandhost
in the diagnostics
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The ssh:// syntax was added in 2386d658 (Add first cut at "git
protocol" connect logic., 2005-07-13), it accepted
ssh://user@2001:db8::1/repo.git, which is now legacy.
Over the years the parser was improved to support [] and port numbers,
but the combination of ssh://user@[2001:db8::1]:222/repo.git did
never work.
The only only way to use a user name, a literall IPV6 address and a port
number was ssh://[user@2001:db8::1]:222/repo.git
(Thanks to Christian Taube <lists@hcf.yourweb.de> for reporting this long
standing issue)
New users would use ssh://user@[2001:db8::1]:222/repo.git,
so change the parser to handle it correctly.
Support the old legacy URLs as well, to be backwards compatible,
and avoid regressions for users which upgrade an existing installation
to a later Git version.
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Get rid of magic string length constants and simply compare the strings
using strcmp(). This makes the intent of the code a bit clearer.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we connect to a git-daemon at a given host and port, we
actually send the string "localhost:9418" to the other side,
which allows it to do virtual-hosting lookups. For testing
and debugging, we'd like to be able to send arbitrary
strings, rather than the hostname we actually connected to.
Using "insteadOf" config does not work for this purpose, as
the hostname determination happens at a very low level,
right before we feed the hostname to our lookup routines.
You could use /etc/hosts or similar to get around this, but
we cannot do that portably from our test suite.
Instead, this patch provides an environment variable that
can be used to send an arbitrary string.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The new name is more consistent with the names of other
string_list-related functions.
Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It may be impractical to install a wrapper script for GIT_SSH
when additional parameters need to be passed. Provide an alternative
way of specifying a shell command to be run, including command line
arguments, by means of the GIT_SSH_COMMAND environment variable,
which behaves like GIT_SSH but is passed to the shell.
The special circuitry to modify parameters in the case of using
PuTTY's plink/tortoiseplink is activated only when using GIT_SSH;
in the case of using GIT_SSH_COMMAND, it is deliberately left up to
the user to make any required parameters adaptation before calling
the underlying ssh implementation.
Signed-off-by: Thomas Quinot <thomas@quinot.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Both callers of check_ref() pass in NUL-terminated strings for name.
Remove the len parameter and then use skip_prefix() and starts_with()
instead of memcmp() to check if it starts with certain strings. This
gets rid of several magic string length constants and a strlen() call.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a helper function for initializing those struct child_process
variables for which the macro CHILD_PROCESS_INIT can't be used.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most struct child_process variables are cleared using memset first after
declaration. Provide a macro, CHILD_PROCESS_INIT, that can be used to
initialize them statically instead. That's shorter, doesn't require a
function call and is slightly more readable (especially given that we
already have STRBUF_INIT, ARGV_ARRAY_INIT etc.).
Helped-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use xmemdupz() to allocate the memory, copy the data and make sure to
NUL-terminate the result, all in one step. The resulting code is
shorter, doesn't contain the constants 1 and '\0', and avoids
duplicating function parameters.
For blame, the last copied byte (o->file.ptr[o->file.size]) is always
set to NUL by fake_working_tree_commit() or read_sha1_file(), so no
information is lost by the conversion to using xmemdupz().
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's a common idiom to match a prefix and then skip past it
with a magic number, like:
if (starts_with(foo, "bar"))
foo += 3;
This is easy to get wrong, since you have to count the
prefix string yourself, and there's no compiler check if the
string changes. We can use skip_prefix to avoid the magic
numbers here.
Note that some of these conversions could be much shorter.
For example:
if (starts_with(arg, "--foo=")) {
bar = arg + 6;
continue;
}
could become:
if (skip_prefix(arg, "--foo=", &bar))
continue;
However, I have left it as:
if (skip_prefix(arg, "--foo=", &v)) {
bar = v;
continue;
}
to visually match nearby cases which need to actually
process the string. Like:
if (skip_prefix(arg, "--foo=", &v)) {
bar = atoi(v);
continue;
}
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This avoids magic numbers when we allocate fixed-size argv
arrays, and makes it more obvious that we are not
overflowing.
It is also the first step to fixing a memory leak. When
git_connect returns a child_process struct, the argv array
in the struct is dynamically allocated, but the individual
strings are not (they are either owned elsewhere, or are
freed). Later, in finish_connect, we free the array but
leave the strings alone.
This works for the child_process created by git_connect, but
if we use transport_take_over, we may also end up with a
child_process created by transport-helper's get_helper.
In that case, the strings are freshly allocated, and we
would want to free them. However, we have no idea in
finish_connect which type we have.
By consistently using run-command's internal argv-array, we
do not have to worry about this issue at all; finish_command
takes care of it for us, and we can drop our manual free
entirely.
Note that this actually makes the get_helper leak slightly
worse; now we are leaking both the strings and the array.
But when we adjust it in a future patch, that leak will go
away entirely.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
No callers pass a non-empty pointer as shallow_points at this
stage. As a result, all clients still refuse to talk to shallow
repository on the other end.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The latter can do everything the former can and is used in many more
places.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use only one return point from git_connect(), doing the
free();
return conn;
only at one place in the code.
There may be a little confusion what the variable "host" is for. At
some places it is only the host part, at other places it may include
the port number, so change host into hostandport here.
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the function is_local() in transport.c public, rename it into
url_is_local_not_ssh() and use it in both transport.c and connect.c
Use a protocol "local" for URLs for the local file system.
One note about using file:// under Windows:
The (absolute) path on Unix like system typically starts with "/".
When the host is empty, it can be omitted, so that a shell scriptlet
url=file://$pwd
will give a URL like "file:///home/user/repo".
Windows does not have the same concept of a root directory located in "/".
When parsing the URL allow "file://C:/user/repo"
(even if RFC1738 indicates that "file:///C:/user/repo" should be used).
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use get_host_and_port() even for ssh.
Remove the variable port git_connect(), and simplify parse_connect_url()
Use only one return point in git_connect(), doing the free() and return conn.
t5601 had 2 corner test cases which now pass.
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The documentation (in urls.txt) says that
"ssh://host:/~repo",
"host:/~repo" or
"host:~repo"
specify the repository "repo" in the home directory at "host".
This has not been working for "host:/~repo".
Before commit 356bec "Support [address] in URLs", the comparison
"url != hostname" could be used to determine if the URL had a scheme
or not: "ssh://host/host" != "host".
However, after 356bec "[::1]" was converted into "::1", yielding
url != hostname as well. To fix this regression, don't use
"if (url != hostname)", but look at the separator instead.
Rename the variable "c" into "separator" to make it easier to read.
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The main purpose is to trace the URL parser called by git_connect() in
connect.c
The main features of the parser can be listed as this:
- parse out host and path for URLs with a scheme (git:// file:// ssh://)
- parse host names embedded by [] correctly
- extract the port number, if present
- separate URLs like "file" (which are local)
from URLs like "host:repo" which should use ssh
Add the new parameter "--diag-url" to "git fetch-pack", which prints
the value for protocol, host and path to stderr and exits.
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git_connect has grown large due to the many different protocols syntaxes
that are supported. Move the part of the function that parses the URL to
connect to into a separate function for readability.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since day one, function git_connect() had a limit on the command line of
the command that is invoked to make a connection. 7a33bcbe converted the
code that constructs the command to strbuf. This would have been the
right time to remove the limit, but it did not happen. Remove it now.
git_connect() uses start_command() to invoke the command; consequently,
the limits of the system still apply, but are diagnosed only at execve()
time. But these limits are more lenient than the 1K that git_connect()
imposed.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Leaving only the function definitions and declarations so that any
new topic in flight can still make use of the old functions, replace
existing uses of the prefixcmp() and suffixcmp() with new API
functions.
The change can be recreated by mechanically applying this:
$ git grep -l -e prefixcmp -e suffixcmp -- \*.c |
grep -v strbuf\\.c |
xargs perl -pi -e '
s|!prefixcmp\(|starts_with\(|g;
s|prefixcmp\(|!starts_with\(|g;
s|!suffixcmp\(|ends_with\(|g;
s|suffixcmp\(|!ends_with\(|g;
'
on the result of preparatory changes in this series.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
commit 6000334 (clone: allow cloning local paths with colons in them -
2013-05-04) made it possible to specify a path that has colons in it
without file://, e.g. ../foo:bar/somewhere. But the check was a bit
sloppy.
Consider the url '[foo]:bar'. The '[]' unwrapping code will turn the
string to 'foo\0:bar'. In effect this new string is the same as
'foo/:bar' in the check "path < strchrnul(host, '/')", which mistakes
it for a local path (with '/' before the first ':') when it's actually
not.
So disable the check for '/' before ':' when the URL has been mangled
by '[]' unwrapping.
[jn: with tests from Jeff King]
Noticed-by: Morten Stenshorne <mstensho@opera.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
By doing this, clients of upload-pack can now reliably tell what ref
a symbolic ref points at; the updated test in t5505 used to expect
failure due to the ambiguity and made sure we give diagnostics, but
we no longer need to be so pessimistic. Make sure we correctly learn
which branch HEAD points at from the other side instead.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The definition of "struct ref" in "cache.h", a header file so
central to the system, always confused me. This structure is not
about the local ref used by sha1-name API to name local objects.
It is what refspecs are expanded into, after finding out what refs
the other side has, to define what refs are updated after object
transfer succeeds to what values. It belongs to "remote.h" together
with "struct refspec".
While we are at it, also move the types and functions related to the
Git transport connection to a new header file connect.h
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Usually "foo:bar" is interpreted as an ssh url. This patch allows to
clone from such paths by putting at least one slash before the colon
(i.e. /path/to/foo:bar or just ./foo:bar).
file://foo:bar should also work, but local optimizations are off in
that case, which may be unwanted. While at there, warn the users about
--local being ignored in this case.
Reported-by: William Giokas <1007380@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that we can read packet data from memory as easily as a
descriptor, get_remote_heads can take either one as a
source. This will allow further refactoring in remote-curl.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The packet_read function reads from a descriptor. The
packet_get_line function is similar, but reads from an
in-memory buffer, and uses a completely separate
implementation. This patch teaches the generic packet_read
function to accept either source, and we can do away with
packet_get_line's implementation.
There are two other differences to account for between the
old and new functions. The first is that we used to read
into a strbuf, but now read into a fixed size buffer. The
only two callers are fine with that, and in fact it
simplifies their code, since they can use the same
static-buffer interface as the rest of the packet_read_line
callers (and we provide a similar convenience wrapper for
reading from a buffer rather than a descriptor).
This is technically an externally-visible behavior change in
that we used to accept arbitrary sized packets up to 65532
bytes, and now cap out at LARGE_PACKET_MAX, 65520. In
practice this doesn't matter, as we use it only for parsing
smart-http headers (of which there is exactly one defined,
and it is small and fixed-size). And any extension headers
would be breaking the protocol to go over LARGE_PACKET_MAX
anyway.
The other difference is that packet_get_line would return
on error rather than dying. However, both callers of
packet_get_line are actually improved by dying.
The first caller does its own error checking, but we can
drop that; as a result, we'll actually get more specific
reporting about protocol breakage when packet_read dies
internally. The only downside is that packet_read will not
print the smart-http URL that failed, but that's not a big
deal; anybody not debugging can already see the remote's URL
already, and anybody debugging would want to run with
GIT_CURL_VERBOSE anyway to see way more information.
The second caller, which is just trying to skip past any
extra smart-http headers (of which there are none defined,
but which we allow to keep room for future expansion), did
not error check at all. As a result, it would treat an error
just like a flush packet. The resulting mess would generally
cause an error later in get_remote_heads, but now we get
error reporting much closer to the source of the problem.
Brown-paper-bag-fixes-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most of the callers of packet_read_line just read into a
static 1000-byte buffer (callers which handle arbitrary
binary data already use LARGE_PACKET_MAX). This works fine
in practice, because:
1. The only variable-sized data in these lines is a ref
name, and refs tend to be a lot shorter than 1000
characters.
2. When sending ref lines, git-core always limits itself
to 1000 byte packets.
However, the only limit given in the protocol specification
in Documentation/technical/protocol-common.txt is
LARGE_PACKET_MAX; the 1000 byte limit is mentioned only in
pack-protocol.txt, and then only describing what we write,
not as a specific limit for readers.
This patch lets us bump the 1000-byte limit to
LARGE_PACKET_MAX. Even though git-core will never write a
packet where this makes a difference, there are two good
reasons to do this:
1. Other git implementations may have followed
protocol-common.txt and used a larger maximum size. We
don't bump into it in practice because it would involve
very long ref names.
2. We may want to increase the 1000-byte limit one day.
Since packets are transferred before any capabilities,
it's difficult to do this in a backwards-compatible
way. But if we bump the size of buffer the readers can
handle, eventually older versions of git will be
obsolete enough that we can justify bumping the
writers, as well. We don't have plans to do this
anytime soon, but there is no reason not to start the
clock ticking now.
Just bumping all of the reading bufs to LARGE_PACKET_MAX
would waste memory. Instead, since most readers just read
into a temporary buffer anyway, let's provide a single
static buffer that all callers can use. We can further wrap
this detail away by having the packet_read_line wrapper just
use the buffer transparently and return a pointer to the
static storage. That covers most of the cases, and the
remaining ones already read into their own LARGE_PACKET_MAX
buffers.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The packets sent during ref negotiation are all terminated
by newline; even though the code to chomp these newlines is
short, we end up doing it in a lot of places.
This patch teaches packet_read_line to auto-chomp the
trailing newline; this lets us get rid of a lot of inline
chomping code.
As a result, some call-sites which are not reading
line-oriented data (e.g., when reading chunks of packfiles
alongside sideband) transition away from packet_read_line to
the generic packet_read interface. This patch converts all
of the existing callsites.
Since the function signature of packet_read_line does not
change (but its behavior does), there is a possibility of
new callsites being introduced in later commits, silently
introducing an incompatibility. However, since a later
patch in this series will change the signature, such a
commit would have to be merged directly into this commit,
not to the tip of the series; we can therefore ignore the
issue.
This is an internal cleanup and should produce no change of
behavior in the normal case. However, there is one corner
case to note. Callers of packet_read_line have never been
able to tell the difference between a flush packet ("0000")
and an empty packet ("0004"), as both cause packet_read_line
to return a length of 0. Readers treat them identically,
even though Documentation/technical/protocol-common.txt says
we must not; it also says that implementations should not
send an empty pkt-line.
By stripping out the newline before the result gets to the
caller, we will now treat the newline-only packet ("0005\n")
the same as an empty packet, which in turn gets treated like
a flush packet. In practice this doesn't matter, as neither
empty nor newline-only packets are part of git's protocols
(at least not for the line-oriented bits, and readers who
are not expecting line-oriented packets will be calling
packet_read directly, anyway). But even if we do decide to
care about the distinction later, it is orthogonal to this
patch. The right place to tighten would be to stop treating
empty packets as flush packets, and this change does not
make doing so any harder.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Lars Schneider