Up until recently, object IDs did not have an algorithm member, only a
hash. Consequently, it was possible to share one null (all-zeros)
object ID among all hash algorithms. Now that we're going to be
handling objects from multiple hash algorithms, it's important to make
sure that all object IDs have a correct algorithm field.
Introduce a per-algorithm null OID, and add it to struct hash_algo.
Introduce a wrapper function as well, and use it everywhere we used to
use the null_oid constant.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach Git to use the "unborn" feature introduced in a previous patch as
follows: Git will always send the "unborn" argument if it is supported
by the server. During "git clone", if cloning an empty repository, Git
will use the new information to determine the local branch to create. In
all other cases, Git will ignore it.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a future patch we plan to return the name of an unborn current branch
from deep in the callchain to a caller via a new pointer parameter that
points at a variable in the caller when the caller calls
get_remote_refs() and transport_get_remote_refs().
In preparation for that, encapsulate the existing ref_prefixes
parameter into a struct. The aforementioned unborn current branch will
go into this new struct in the future patch.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we connect to a git:// server, we send an initial request that
looks something like:
002dgit-upload-pack repo.git\0host=example.com
If the repo path contains a newline, then it's included literally, and
we get:
002egit-upload-pack repo
.git\0host=example.com
This works fine if you really do have a newline in your repository name;
the server side uses the pktline framing to parse the string, not
newlines. However, there are many _other_ protocols in the wild that do
parse on newlines, such as HTTP. So a carefully constructed git:// URL
can actually turn into a valid HTTP request. For example:
git://localhost:1234/%0d%0a%0d%0aGET%20/%20HTTP/1.1 %0d%0aHost:localhost%0d%0a%0d%0a
becomes:
0050git-upload-pack /
GET / HTTP/1.1
Host:localhost
host=localhost:1234
on the wire. Again, this isn't a problem for a real Git server, but it
does mean that feeding a malicious URL to Git (e.g., through a
submodule) can cause it to make unexpected cross-protocol requests.
Since repository names with newlines are presumably quite rare (and
indeed, we already disallow them in git-over-http), let's just disallow
them over this protocol.
Hostnames could likewise inject a newline, but this is unlikely a
problem in practice; we'd try resolving the hostname with a newline in
it, which wouldn't work. Still, it doesn't hurt to err on the side of
caution there, since we would not expect them to work in the first
place.
The ssh and local code paths are unaffected by this patch. In both cases
we're trying to run upload-pack via a shell, and will quote the newline
so that it makes it intact. An attacker can point an ssh url at an
arbitrary port, of course, but unless there's an actual ssh server
there, we'd never get as far as sending our shell command anyway. We
_could_ similarly restrict newlines in those protocols out of caution,
but there seems little benefit to doing so.
The new test here is run alongside the git-daemon tests, which cover the
same protocol, but it shouldn't actually contact the daemon at all. In
theory we could make the test more robust by setting up an actual
repository with a newline in it (so that our clone would succeed if our
new check didn't kick in). But a repo directory with newline in it is
likely not portable across all filesystems. Likewise, we could check
git-daemon's log that it was not contacted at all, but we do not
currently record the log (and anyway, it would make the test racy with
the daemon's log write). We'll just check the client-side stderr to make
sure we hit the expected code path.
Reported-by: Harold Kim <h.kim@flatt.tech>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are two functions to get a single config string:
- git_config_get_string()
- git_config_get_string_const()
One might naively think that the first one allocates a new string and
the second one just points us to the internal configset storage. But
in fact they both allocate a new copy; the second one exists only to
avoid having to cast when using it with a const global which we never
intend to free.
The documentation for the function explains that clearly, but it seems
I'm not alone in being surprised by this. Of 17 calls to the function,
13 of them leak the resulting value.
We could obviously fix these by adding the appropriate free(). But it
would be simpler still if we actually had a non-allocating way to get
the string. There's git_config_get_value() but that doesn't quite do
what we want. If the config key is present but is a boolean with no
value (e.g., "[foo]bar" in the file), then we'll get NULL (whereas the
string versions will print an error and die).
So let's introduce a new variant, git_config_get_string_tmp(), that
behaves as these callers expect. We need a new name because we have new
semantics but the same function signature (so even if we converted the
four remaining callers, topics in flight might be surprised). The "tmp"
is because this value should only be held onto for a short time. In
practice it's rare for us to clear and refresh the configset,
invalidating the pointer, but hopefully the "tmp" makes callers think
about the lifetime. In each of the converted cases here the value only
needs to last within the local function or its immediate caller.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "argc" and "argv" names made sense when the struct was argv_array,
but now they're just confusing. Let's rename them to "nr" (which we use
for counts elsewhere) and "v" (which is rather terse, but reads well
when combined with typical variable names like "args.v").
Note that we have to update all of the callers immediately. Playing
tricks with the preprocessor is hard here, because we wouldn't want to
rewrite unrelated tokens.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code which split an argv_array call across multiple lines, like:
argv_array_pushl(&args, "one argument",
"another argument", "and more",
NULL);
was recently mechanically renamed to use strvec, which results in
mis-matched indentation like:
strvec_pushl(&args, "one argument",
"another argument", "and more",
NULL);
Let's fix these up to align the arguments with the opening paren. I did
this manually by sifting through the results of:
git jump grep 'strvec_.*,$'
and liberally applying my editor's auto-format. Most of the changes are
of the form shown above, though I also normalized a few that had
originally used a single-tab indentation (rather than our usual style of
aligning with the open paren). I also rewrapped a couple of obvious
cases (e.g., where previously too-long lines became short enough to fit
on one), but I wasn't aggressive about it. In cases broken to three or
more lines, the grouping of arguments is sometimes meaningful, and it
wasn't worth my time or reviewer time to ponder each case individually.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We eventually want to drop the argv_array name and just use strvec
consistently. There's no particular reason we have to do it all at once,
or care about interactions between converted and unconverted bits.
Because of our preprocessor compat layer, the names are interchangeable
to the compiler (so even a definition and declaration using different
names is OK).
This patch converts remaining files from the first half of the alphabet,
to keep the diff to a manageable size.
The conversion was done purely mechanically with:
git ls-files '*.c' '*.h' |
xargs perl -i -pe '
s/ARGV_ARRAY/STRVEC/g;
s/argv_array/strvec/g;
'
and then selectively staging files with "git add '[abcdefghjkl]*'".
We'll deal with any indentation/style fallouts separately.
Signed-off-by: Jeff King <peff@peff.net>
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>
When using protocol v2, we need to know what hash algorithm is used by
the remote end. See if the server has sent us an object-format
capability, and if so, use it to determine the hash algorithm in use and
set that value in the packet reader. Parse the refs using this
algorithm.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we're parsing refs, we need to know not only what the line we're
parsing is, but also the hash algorithm we should use to parse it, which
is stored in the reader object. Pass the packet reader object through
to the protocol v2 ref parsing function.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we're fetching refs, detect the hash algorithm and parse the refs
using that algorithm.
As mentioned in the documentation, if multiple versions of the
object-format capability are provided, we use the first. No known
implementation supports multiple algorithms now, but they may in the
future.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We're going to be using this function in other files, so no longer mark
this function static.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a function, server_supports_hash, to see if the remote server
supports a particular hash algorithm when speaking protocol v1.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
So far in protocol v2, all of our server capabilities that have values
have not had values that we've been interested in parsing. For example,
we receive but ignore the agent value.
However, in a future commit, we're going to want to parse out the value
of a server capability. To make this easy, add a function,
server_feature_v2, that can fetch the value provided as part of the
server capability.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a capability response, we can have multiple symref entries. In the
future, we will also allow for multiple hash algorithms to be specified.
To avoid duplication, expand the parse_feature_value function to take an
optional offset where the parsing should begin next time. Add a wrapper
function that allows us to query the next server feature value, and use
it in the existing symref parsing code.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a future patch, we'll want to access multiple members from struct
packet_reader when parsing references. Therefore, have the ref parsing
code take pointers to struct reader instead of having to pass multiple
arguments to each function.
Rename the len variable to "linelen" to make it clearer what the
variable does in light of the variable change.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, remote-curl acts as a proxy and blindly forwards packets
between an HTTP server and fetch-pack. In the case of a stateless RPC
connection where the connection is terminated before the transaction is
complete, remote-curl will blindly forward the packets before waiting on
more input from fetch-pack. Meanwhile, fetch-pack will read the
transaction and continue reading, expecting more input to continue the
transaction. This results in a deadlock between the two processes.
This can be seen in the following command which does not terminate:
$ git -c protocol.version=2 clone https://github.com/git/git.git --shallow-since=20151012
Cloning into 'git'...
whereas the v1 version does terminate as expected:
$ git -c protocol.version=1 clone https://github.com/git/git.git --shallow-since=20151012
Cloning into 'git'...
fatal: the remote end hung up unexpectedly
Instead of blindly forwarding packets, make remote-curl insert a
response end packet after proxying the responses from the remote server
when using stateless_connect(). On the RPC client side, ensure that each
response ends as described.
A separate control packet is chosen because we need to be able to
differentiate between what the remote server sends and remote-curl's
control packets. By ensuring in the remote-curl code that a server
cannot send response end packets, we prevent a malicious server from
being able to perform a denial of service attack in which they spoof a
response end packet and cause the described deadlock to happen.
Reported-by: Force Charlie <charlieio@outlook.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a future commit, we will use PACKET_READ_RESPONSE_END to separate
messages proxied by remote-curl. To prepare for this, add the
PACKET_READ_RESPONSE_END enum value.
In switch statements that need a case added, die() or BUG() when a
PACKET_READ_RESPONSE_END is unexpected. Otherwise, mirror how
PACKET_READ_DELIM is implemented (especially in cases where packets are
being forwarded).
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We renamed the actual data structure in 910650d2f8 (Rename sha1_array to
oid_array, 2017-03-31), but the file is still called sha1-array. Besides
being slightly confusing, it makes it more annoying to grep for leftover
occurrences of "sha1" in various files, because the header is included
in so many places.
Let's complete the transition by renaming the source and header files
(and fixing up a few comment references).
I kept the "-" in the name, as that seems to be our style; cf.
fc1395f4a4 (sha1_file.c: rename to use dash in file name, 2018-04-10).
We also have oidmap.h and oidset.h without any punctuation, but those
are "struct oidmap" and "struct oidset" in the code. We _could_ make
this "oidarray" to match, but somehow it looks uglier to me because of
the length of "array" (plus it would be a very invasive patch for little
gain).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Over a decade ago, in 25fe217b86 (Windows: Treat Windows style path
names., 2008-03-05), Git was taught to handle absolute Windows paths,
i.e. paths that start with a drive letter and a colon.
Unbeknownst to us, while drive letters of physical drives are limited to
letters of the English alphabet, there is a way to assign virtual drive
letters to arbitrary directories, via the `subst` command, which is
_not_ limited to English letters.
It is therefore possible to have absolute Windows paths of the form
`1:\what\the\hex.txt`. Even "better": pretty much arbitrary Unicode
letters can also be used, e.g. `ä:\tschibät.sch`.
While it can be sensibly argued that users who set up such funny drive
letters really seek adverse consequences, the Windows Operating System
is known to be a platform where many users are at the mercy of
administrators who have their very own idea of what constitutes a
reasonable setup.
Therefore, let's just make sure that such funny paths are still
considered absolute paths by Git, on Windows.
In addition to Unicode characters, pretty much any character is a valid
drive letter, as far as `subst` is concerned, even `:` and `"` or even a
space character. While it is probably the opposite of smart to use them,
let's safeguard `is_dos_drive_prefix()` against all of them.
Note: `[::1]:repo` is a valid URL, but not a valid path on Windows.
As `[` is now considered a valid drive letter, we need to be very
careful to avoid misinterpreting such a string as valid local path in
`url_is_local_not_ssh()`. To do that, we use the just-introduced
function `is_valid_path()` (which will label the string as invalid file
name because of the colon characters).
This fixes CVE-2019-1351.
Reported-by: Nicolas Joly <Nicolas.Joly@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Extend the parser to accept file://server/share/repo in the way that
Windows users expect it to be parsed who are used to referring to file
shares by UNC paths of the form \\server\share\folder.
[jes: tightened check to avoid handling file://C:/some/path as a UNC
path.]
This closes https://github.com/git-for-windows/git/issues/1264.
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add trace2 child classification for transport processes.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the Git pack protocol definition, an error packet may appear only in
a certain context. However, servers can face a runtime error (e.g. I/O
error) at an arbitrary timing. This patch changes the protocol to allow
an error packet to be sent instead of any packet.
Without this protocol spec change, when a server cannot process a
request, there's no way to tell that to a client. Since the server
cannot produce a valid response, it would be forced to cut a connection
without telling why. With this protocol spec change, the server can be
more gentle in this situation. An old client may see these error packets
as an unexpected packet, but this is not worse than having an unexpected
EOF.
Following this protocol spec change, the error packet handling code is
moved to pkt-line.c. Implementation wise, this implementation uses
pkt-line to communicate with a subprocess. Since this is not a part of
Git protocol, it's possible that a packet that is not supposed to be an
error packet is mistakenly parsed as an error packet. This error packet
handling is enabled only for the Git pack protocol parsing code
considering this.
Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Using the more restrictive oideq() should, in the long run,
give the compiler more opportunities to optimize these
callsites. For now, this conversion should be a complete
noop with respect to the generated code.
The result is also perhaps a little more readable, as it
avoids the "zero is equal" idiom. Since it's so prevalent in
C, I think seasoned programmers tend not to even notice it
anymore, but it can sometimes make for awkward double
negations (e.g., we can drop a few !!oidcmp() instances
here).
This patch was generated almost entirely by the included
coccinelle patch. This mechanical conversion should be
completely safe, because we check explicitly for cases where
oidcmp() is compared to 0, which is what oideq() is doing
under the hood. Note that we don't have to catch "!oidcmp()"
separately; coccinelle's standard isomorphisms make sure the
two are treated equivalently.
I say "almost" because I did hand-edit the coccinelle output
to fix up a few style violations (it mostly keeps the
original formatting, but sometimes unwraps long lines).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Many messages will be marked for translation in the following
commits. This commit updates some of them to be more consistent and
reduce diff noise in those commits. Changes are
- keep the first letter of die(), error() and warning() in lowercase
- no full stop in die(), error() or warning() if it's single sentence
messages
- indentation
- some messages are turned to BUG(), or prefixed with "BUG:" and will
not be marked for i18n
- some messages are improved to give more information
- some messages are broken down by sentence to be i18n friendly
(on the same token, combine multiple warning() into one big string)
- the trailing \n is converted to printf_ln if possible, or deleted
if not redundant
- errno_errno() is used instead of explicit strerror()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach ls-remote to optionally accept server options by specifying them
on the cmdline via '-o' or '--server-option'. These server options are
sent to the remote end when querying for the remote end's refs using
protocol version 2.
If communicating using a protocol other than v2 the provided options are
ignored and not sent to the remote end.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There is a series running in parallel with this one that adds code
like this
switch (...) {
case ...:
die_initial_contact();
case ...:
There is nothing wrong with this. There is no actual falling
through. But since gcc is not that smart and gcc 7.x introduces
-Wimplicit-fallthrough, it raises a false alarm in this case.
This class of warnings may be useful elsewhere, so instead of
suppressing the whole class, let's try to fix just this code. gcc is
smart enough to realize that no execution can continue after a
NORETURN function call and no longer raises the warning.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to be able to ship protocol v2 with only supporting fetch, we
need clients to not issue a request to use protocol v2 when pushing
(since the client currently doesn't know how to push using protocol v2).
This allows a client to have protocol v2 configured in
`protocol.version` and take advantage of using v2 for fetch and falling
back to using v0 when pushing while v2 for push is being designed.
We could run into issues if we didn't fall back to protocol v2 when
pushing right now. This is because currently a server will ignore a request to
use v2 when contacting the 'receive-pack' endpoint and fall back to
using v0, but when push v2 is rolled out to servers, the 'receive-pack'
endpoint will start responding using v2. So we don't want to get into a
state where a client is requesting to push with v2 before they actually
know how to push using v2.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of having each builtin transport asking for which protocol
version the user has configured in 'protocol.version' by calling
`get_protocol_version_config()` multiple times, factor this logic out
so there is just a single call at the beginning of `git_connect()`.
This will be helpful in the next patch where we can have centralized
logic which determines if we need to request a different protocol
version than what the user has configured.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Enable shallow clones and deepen requests using protocol version 2 if
the server 'fetch' command supports the 'shallow' feature.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach the client to be able to request a remote's refs using protocol
v2. This is done by having a client issue a 'ls-refs' request to a v2
server.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce protocol_v2, a new value for 'enum protocol_version'.
Subsequent patches will fill in the implementation of protocol_v2.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to prepare for the addition of protocol_v2 push the protocol
version discovery outside of 'get_remote_heads()'. This will allow for
keeping the logic for processing the reference advertisement for
protocol_v1 and protocol_v0 separate from the logic for protocol_v2.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to allow for better control flow when protocol_v2 is introduced
convert 'get_remote_heads()' to use 'struct packet_reader' to read
packet lines. This enables a client to be able to peek the first line
of a server's response (without consuming it) in order to determine the
protocol version its speaking and then passing control to the
appropriate handler.
This is needed because the initial response from a server speaking
protocol_v0 includes the first ref, while subsequent protocol versions
respond with a version line. We want to be able to read this first line
without consuming the first ref sent in the protocol_v0 case so that the
protocol version the server is speaking can be determined outside of
'get_remote_heads()' in a future patch.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation/CodingGuidelines explains:
- Multi-line comments include their delimiters on separate lines from
the text. E.g.
/*
* A very long
* multi-line comment.
*/
Reported-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When trying to connect to an ssh:// URL with port explicitly specified
and the ssh command configured with GIT_SSH does not support such a
setting, it is less confusing to error out than to silently suppress
the port setting and continue.
This requires updating the GIT_SSH setting in t5603-clone-dirname.sh.
That test is about the directory name produced when cloning various
URLs. It uses an ssh wrapper that ignores all its arguments but does
not declare that it supports a port argument; update it to set
GIT_SSH_VARIANT=ssh to do so. (Real-life ssh wrappers that pass a
port argument to OpenSSH would also support -G and would not require
such an update.)
Reported-by: William Yan <wyan@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Acked-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If the user passes -4/--ipv4 or -6/--ipv6 to "git fetch" or "git push"
and the ssh command configured with GIT_SSH does not support such a
setting, error out instead of ignoring the option and continuing.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Acked-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Android's "repo" tool is a tool for managing a large codebase
consisting of multiple smaller repositories, similar to Git's
submodule feature. Starting with Git 94b8ae5a (ssh: introduce a
'simple' ssh variant, 2017-10-16), users noticed that it stopped
handling the port in ssh:// URLs.
The cause: when it encounters ssh:// URLs, repo pre-connects to the
server and sets GIT_SSH to a helper ".repo/repo/git_ssh" that reuses
that connection. Before 94b8ae5a, the helper was assumed to support
OpenSSH options for lack of a better guess and got passed a -p option
to set the port. After that patch, it uses the new default of a
simple helper that does not accept an option to set the port.
The next release of "repo" will set GIT_SSH_VARIANT to "ssh" to avoid
that. But users of old versions and of other similar GIT_SSH
implementations would not get the benefit of that fix.
So update the default to use OpenSSH options again, with a twist. As
observed in 94b8ae5a, we cannot assume that $GIT_SSH always handles
OpenSSH options: common helpers such as travis-ci's dpl[*] are
configured using GIT_SSH and do not accept OpenSSH options. So make
the default a new variant "auto", with the following behavior:
1. First, check for a recognized basename, like today.
2. If the basename is not recognized, check whether $GIT_SSH supports
OpenSSH options by running
$GIT_SSH -G <options> <host>
This returns status 0 and prints configuration in OpenSSH if it
recognizes all <options> and returns status 255 if it encounters
an unrecognized option. A wrapper script like
exec ssh -- "$@"
would fail with
ssh: Could not resolve hostname -g: Name or service not known
, correctly reflecting that it does not support OpenSSH options.
The command is run with stdin, stdout, and stderr redirected to
/dev/null so even a command that expects a terminal would exit
immediately.
3. Based on the result from step (2), behave like "ssh" (if it
succeeded) or "simple" (if it failed).
This way, the default ssh variant for unrecognized commands can handle
both the repo and dpl cases as intended.
This autodetection has been running on Google workstations since
2017-10-23 with no reported negative effects.
[*] 6c3fddfda1/lib/dpl/provider.rb (L215)
Reported-by: William Yan <wyan@google.com>
Improved-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This puts the determination of options to pass to each ssh variant
(see ssh.variant in git-config(1)) in one place.
A follow-up patch will use this in an initial dry run to detect which
variant to use when the ssh command is ambiguous.
No functional change intended yet.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git_connect function is growing long. Split the portion that
discovers an ssh command and options it accepts before the service
name and path to a separate function to make it easier to read.
No functional change intended.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git_connect function is growing long. Split the
PROTO_GIT-specific portion to a separate function to make it easier to
read.
No functional change intended.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git_connect has the structure
struct child_process *conn = &no_fork;
...
switch (protocol) {
case PROTO_GIT:
if (git_use_proxy(hostandport))
conn = git_proxy_connect(fd, hostandport);
else
git_tcp_connect(fd, hostandport, flags);
...
break;
case PROTO_SSH:
conn = xmalloc(sizeof(*conn));
child_process_init(conn);
argv_array_push(&conn->args, ssh);
...
break;
...
return conn;
In all cases except the git_tcp_connect case, conn is explicitly
assigned a value. Make the code clearer by explicitly assigning
'conn = &no_fork' in the tcp case and eliminating the default so the
compiler can ensure conn is always correctly assigned.
Noticed-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When using the 'ssh' transport, the '-o' option is used to specify an
environment variable which should be set on the remote end. This allows
git to send additional information when contacting the server,
requesting the use of a different protocol version via the
'GIT_PROTOCOL' environment variable like so: "-o SendEnv=GIT_PROTOCOL".
Unfortunately not all ssh variants support the sending of environment
variables to the remote end. To account for this, only use the '-o'
option for ssh variants which are OpenSSH compliant. This is done by
checking that the basename of the ssh command is 'ssh' or the ssh
variant is overridden to be 'ssh' (via the ssh.variant config).
Other options like '-p' and '-P', which are used to specify a specific
port to use, or '-4' and '-6', which are used to indicate that IPV4 or
IPV6 addresses should be used, may also not be supported by all ssh
variants.
Currently if an ssh command's basename wasn't 'plink' or
'tortoiseplink' git assumes that the command is an OpenSSH variant.
Since user configured ssh commands may not be OpenSSH compliant, tighten
this constraint and assume a variant of 'simple' if the basename of the
command doesn't match the variants known to git. The new ssh variant
'simple' will only have the host and command to execute ([username@]host
command) passed as parameters to the ssh command.
Update the Documentation to better reflect the command-line options sent
to ssh commands based on their variant.
Reported-by: Jeffrey Yasskin <jyasskin@google.com>
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach the connection logic to tell a serve that it understands protocol
v1. This is done in 2 different ways for the builtin transports, both
of which ultimately set 'GIT_PROTOCOL' to 'version=1' on the server.
1. git://
A normal request to git-daemon is structured as
"command path/to/repo\0host=..\0" and due to a bug introduced in
49ba83fb6 (Add virtualization support to git-daemon, 2006-09-19) we
aren't able to place any extra arguments (separated by NULs) besides
the host otherwise the parsing of those arguments would enter an
infinite loop. This bug was fixed in 73bb33a94 (daemon: Strictly
parse the "extra arg" part of the command, 2009-06-04) but a check
was put in place to disallow extra arguments so that new clients
wouldn't trigger this bug in older servers.
In order to get around this limitation git-daemon was taught to
recognize additional request arguments hidden behind a second
NUL byte. Requests can then be structured like:
"command path/to/repo\0host=..\0\0version=1\0key=value\0".
git-daemon can then parse out the extra arguments and set
'GIT_PROTOCOL' accordingly.
By placing these extra arguments behind a second NUL byte we can
skirt around both the infinite loop bug in 49ba83fb6 (Add
virtualization support to git-daemon, 2006-09-19) as well as the
explicit disallowing of extra arguments introduced in 73bb33a94
(daemon: Strictly parse the "extra arg" part of the command,
2009-06-04) because both of these versions of git-daemon check for a
single NUL byte after the host argument before terminating the
argument parsing.
2. ssh://, file://
Set 'GIT_PROTOCOL' environment variable with the desired protocol
version. With the file:// transport, 'GIT_PROTOCOL' can be set
explicitly in the locally running git-upload-pack or git-receive-pack
processes. With the ssh:// transport and OpenSSH compliant ssh
programs, 'GIT_PROTOCOL' can be sent across ssh by using '-o
SendEnv=GIT_PROTOCOL' and having the server whitelist this
environment variable.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach a client to recognize that a server understands protocol v1 by
looking at the first pkt-line the server sends in response. This is
done by looking for the response "version 1" send by upload-pack or
receive-pack.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, get_remote_heads() parses the ref advertisement in one loop,
allowing refs and shallow lines to intersperse, despite this not being
allowed by the specification. Refactor get_remote_heads() to use two
loops instead, enforcing that refs come first, and then shallows.
This also makes it easier to teach get_remote_heads() to interpret other
lines in the ref advertisement, which will be done in a subsequent
patch.
As part of this change, this patch interprets capabilities only on the
first line in the ref advertisement, printing a warning message when
encountering capabilities on other lines.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reduce the scope of the variable cmd and release it before returning
early.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson