"git fetch" and "git upload-pack" learned to send all exchange over
the sideband channel while talking the v2 protocol.
* jt/fetch-v2-sideband:
tests: define GIT_TEST_SIDEBAND_ALL
{fetch,upload}-pack: sideband v2 fetch response
sideband: reverse its dependency on pkt-line
pkt-line: introduce struct packet_writer
pack-protocol.txt: accept error packets in any context
Use packet_reader instead of packet_read_line
Currently, a response to a fetch request has sideband support only while
the packfile is being sent, meaning that the server cannot send notices
until the start of the packfile.
Extend sideband support in protocol v2 fetch responses to the whole
response. upload-pack will advertise it if the
uploadpack.allowsidebandall configuration variable is set, and
fetch-pack will automatically request it if advertised.
If the sideband is to be used throughout the whole response, upload-pack
will use it to send errors instead of prefixing a PKT-LINE payload with
"ERR ".
This will be tested in a subsequent patch.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A subsequent patch will teach struct packet_reader a new field that, if
set, instructs it to interpret read data as multiplexed. This will
create a dependency from pkt-line to sideband.
To avoid a circular dependency, split recv_sideband() into 2 parts: the
reading loop (left in recv_sideband()) and the processing of the
contents (in demultiplex_sideband()), and move the former into pkt-line.
This reverses the direction of dependency: sideband no longer depends on
pkt-line, and pkt-line now depends on sideband.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When bf1a11f0a1 (sideband: highlight keywords in remote sideband output,
2018-08-07) was introduced, it was carefully considered which strings
would be highlighted. However 59a255aef0 (sideband: do not read beyond
the end of input, 2018-08-18) brought in a regression that the original
did not test for. A line containing only the keyword and nothing else
("SUCCESS") should still be colored.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The caller of maybe_colorize_sideband() gives a counted buffer
<src, n>, but the callee checked src[] as if it were a NUL terminated
buffer. If src[] had all isspace() bytes in it, we would have made
n negative, and then
(1) made number of strncasecmp() calls to see if the remaining
bytes in src[] matched keywords, reading beyond the end of the
array (this actually happens even if n does not go negative),
and/or
(2) called strbuf_add() with negative count, most likely triggering
the "you want to use way too much memory" error due to unsigned
integer overflow.
Fix both issues by making sure we do not go beyond &src[n].
In the longer term we may want to accept size_t as parameter for
clarity (even though we know that a sideband message we are painting
typically would fit on a line on a terminal and int is sufficient).
Write it down as a NEEDSWORK comment.
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The colorization is controlled with the config setting "color.remote".
Supported keywords are "error", "warning", "hint" and "success". They
are highlighted if they appear at the start of the line, which is
common in error messages, eg.
ERROR: commit is missing Change-Id
The Git push process itself prints lots of non-actionable messages
(eg. bandwidth statistics, object counters for different phases of the
process). This obscures actionable error messages that servers may
send back. Highlighting keywords in the sideband draws more attention
to those messages.
The background for this change is that Gerrit does server-side
processing to create or update code reviews, and actionable error
messages (eg. missing Change-Id) must be communicated back to the user
during the push. User research has shown that new users have trouble
seeing these messages.
The highlighting is done on the client rather than server side, so
servers don't have to grow capabilities to understand terminal escape
codes and terminal state. It also consistent with the current state
where Git is control of the local display (eg. prefixing messages with
"remote: ").
The highlighting can be configured using color.remote.<KEYWORD>
configuration settings. Since the keys are matched case insensitively,
we match the keywords case insensitively too.
Finally, this solution is backwards compatible: many servers already
prefix their messages with "error", and they will benefit from this
change without requiring a server update. By contrast, a server-side
solution would likely require plumbing the TERM variable through the
git protocol, so it would require changes to both server and client.
Helped-by: Duy Nguyen <pclouds@gmail.com>
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The short and sweet PREFIX can be confused when used in many places.
Rename both usages to better describe their purpose. EXEC_CMD_PREFIX is
used in full to disambiguate it from the nearby GIT_EXEC_PATH.
The PREFIX in sideband.c, while nominally independant of the exec_cmd
PREFIX, does reside within libgit[1], so the definitions would clash
when taken together with a PREFIX given on the command line for use by
exec_cmd.c.
Noticed when compiling Git for Windows using MSVC/Visual Studio [1] which
reports the conflict beteeen the command line definition and the
definition in sideband.c within the libgit project.
[1] the libgit functions are brought into a single sub-project
within the Visual Studio construction script provided in contrib,
and hence uses a single command for both exec_cmd.c and sideband.c.
Signed-off-by: Philip Oakley <philipoakley@iee.org>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the code to detect "dumb" terminals into a single location. This
avoids duplicating the terminal detection code yet again in a subsequent
commit.
Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We used character buffer manipulations to split messages from the
sideband at line breaks and insert "remote: " at the beginning of
each line, using the packet size to determine the end of a message.
However, since it is safe to assume that diagnostic messages from
the sideband never contain NUL characters, we can also NUL-terminate
the buffer, use strpbrk() for splitting lines and use format strings
to insert the prefix, to make the code easier to read and maintain.
A strbuf is used for accumulating the output which is then printed
using a single write(2) call to ensure the atomicity of the output.
See 9ac13ec (atomic write for sideband remote messages, 2006-10-11)
for details.
Helped-by: Jeff King <peff@peff.net>
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Lukas Fleischer <lfleischer@lfos.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The send_sideband() function uses write_or_die() for writing data which
immediately terminates the process on errors. If no such error occurred,
send_sideband() always returned the value that was passed as fourth
parameter prior to this commit. This value is already known to the
caller in any case, so let's turn send_sideband() into a void function
instead.
Signed-off-by: Lukas Fleischer <lfleischer@lfos.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
Diagnostic messages received on the sideband #2 from the server side
are sent to the standard error with ANSI terminal control sequence
"\033[K" that erases to the end of line appended at the end of each
line.
However, some programs (e.g. GitExtensions for Windows) read and
interpret and/or show the message without understanding the terminal
control sequences, resulting them to be shown to their end users.
To help these programs, squelch the control sequence when the
standard error stream is not being sent to a tty.
NOTE: I considered to cover the case that a pager has already been
started. But decided that is probably not worth worrying about here,
though, as we shouldn't be using a pager for commands that do network
communications (and if we do, omitting the magic line-clearing signal
is probably a sane thing to do).
Thanks-to: Erik Faye-Lund <kusmabite@gmail.com>
Thanks-to: Jeff King <peff@peff.net>
Signed-off-by: Michael Naumov <mnaoumov@gmail.com>
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>
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>
This is just write_or_die by another name. The one
distinction is that write_or_die will treat EPIPE specially
by suppressing error messages. That's fine, as we die by
SIGPIPE anyway (and in the off chance that it is disabled,
write_or_die will simulate it).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git-remote-curl backend detects if the remote server supports
the git-receive-pack service, and if so, runs git-send-pack in a
pipe to dump the command and pack data as a single POST request.
The advertisements from the server that were obtained during the
discovery are passed into git-send-pack before the POST request
starts. This permits git-send-pack to operate largely unmodified.
For smaller packs (those under 1 MiB) a HTTP/1.0 POST with a
Content-Length is used, permitting interaction with any server.
The 1 MiB limit is arbitrary, but is sufficent to fit most deltas
created by human authors against text sources with the occasional
small binary file (e.g. few KiB icon image). The configuration
option http.postBuffer can be used to increase (or shink) this
buffer if the default is not sufficient.
For larger packs which cannot be spooled entirely into the helper's
memory space (due to http.postBuffer being too small), the POST
request requires HTTP/1.1 and sets "Transfer-Encoding: chunked".
This permits the client to upload an unknown amount of data in one
HTTP transaction without needing to pregenerate the entire pack
file locally.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
CC: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This removes the last parameter of recv_sideband, by which the callers
told which channel bands #2 and #3 should be written to.
Sayeth Shawn Pearce:
The definition of the streams in the current sideband protocol
are rather well defined for the one protocol that uses it,
fetch-pack/receive-pack:
stream #1: pack data
stream #2: stderr messages, progress, meant for tty
stream #3: abort message, remote is dead, goodbye!
Since both callers of the function passed 2 for the parameter, we hereby
remove it and send bands #2 and #3 to stderr explicitly using fprintf.
This has the nice side-effect that these two streams pass through our
ANSI emulation layer on Windows.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Acked-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently the code looks for line break characters in order to prepend
"remote: " to every line received as many lines can be sent in a single
chunk. However the opposite might happen too, i.e. a single message
line split amongst multiple chunks. This patch adds support for the
later case to avoid displays like:
remote: Compressing objeremote: cts: 100% (313/313), done.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "clear to end of line" sequence is used to nicely output the progress
indicator without leaving garbage on the terminal. However, this works
only on ANSI capable terminals. We use the same check as in color.c to
find out whether the terminal supports this feature and use a workaround
(a few spaces in a row) if it does not.
[jc: as an old fashoned git myself, and given the fact that the
possible prefix and suffix are small number of short constant strings,
I actually prefer a simpler-and-more-stupid approach. This is with
Nico's clean-up.]
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is possible for the remote summary line to be displayed over the
local progress display line, and therefore that local progress gets
bumped to the next line. However, if the progress line is long enough,
it might not be entirely overwritten by the remote summary line. This
creates a messed up display such as:
remote: Total 310 (delta 160), reused 178 (delta 112)iB/s
Receiving objects: 100% (310/310), 379.98 KiB | 136 KiB/s, done.
So we have to clear the screen line before displaying the remote message
to make sure the local progress is not visible anymore on the first
line.
Yet some Git versions on the remote side might be sending updates to the
same line and terminate it with \r, and a separate packet with a single
\n might be sent later when the progress display is done. This means
the screen line must *not* be cleared in that case.
Since the sideband code already has to figure out line breaks in the
received packet to properly prepend the "remote:" prefix, we can easily
determine if the remote line about to be displayed is empty. Only when
it is not then a proper suffix is inserted before the \r or \n to clear
the end of the screen line.
Also some magic constants related to the prefix length have been
replaced with a variable, making it similar to the suffix length
handling. Since gcc is smart enough to detect that the variable is
constant there is no impact on the generated code.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A single sideband packet may sometimes contain multiple lines of progress
messages, but we prepend "remote: " only to the whole buffer which creates
a messed up display in that case. Make sure that the "remote: " prefix
is applied to every remote lines.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
It has been a few times that I ended up with such a confusing display:
|remote: Generating pack...
|remote: Done counting 17 objects.
|remote: Result has 9 objects.
|remote: Deltifying 9 objects.
|remote: 100% (9/9) done
|remote: Unpacking 9 objects
|Total 9, written 9 (delta 8), reused 0 (delta 0)
| 100% (9/9) done
The confusion can be avoided in most cases by writing the remote message
in one go to prevent interleacing with local messages. The buffer
declaration has been moved inside recv_sideband() to avoid extra string
copies.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
The server side support; this is just the very low level, and the
caller needs to know which band it wants to send things out.
Signed-off-by: Junio C Hamano <junkio@cox.net>
(cherry picked from b786552b67878c7780c50def4c069d46dc54efbe commit)
This moves the receiver side of the sideband support from
fetch-clone.c to sideband.c and its header file, so that
archiver protocol can use it.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Junio C Hamano
Jonathan Tan
Stefan Beller
Han-Wen Nienhuys
Philip Oakley
Lars Schneider
Nicolas Pitre
Lukas Fleischer
Jeff King
Michael Naumov
Shawn O. Pearce
Johannes Sixt
Nicolas Pitre
Johannes Sixt
Junio C Hamano