Commit Graph

248 Commits

Author SHA1 Message Date
Junio C Hamano
9afe4d9f6b Merge branch 'rs/daemon-plug-leak'
Plug a memory leak.

* rs/daemon-plug-leak:
  daemon: plug memory leak on overlong path
2022-01-05 14:01:31 -08:00
René Scharfe
999bba3e0b daemon: plug memory leak on overlong path
Release the strbuf containing the interpolated path after copying it to
a stack buffer and before erroring out if it's too long.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-20 12:43:18 -08:00
Ævar Arnfjörð Bjarmason
7f14609e29 run-command API users: use strvec_push(), not argv construction
Change a pattern of hardcoding an "argv" array size, populating it and
assigning to the "argv" member of "struct child_process" to instead
use "strvec_push()" to add data to the "args" member.

As noted in the preceding commit this moves us further towards being
able to remove the "argv" member in a subsequent commit

These callers could have used strvec_pushl(), but moving to
strvec_push() makes the diff easier to read, and keeps the arguments
aligned as before.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-25 22:15:07 -08:00
Ævar Arnfjörð Bjarmason
6def0ff878 run-command API users: use strvec_pushv(), not argv assignment
Migrate those run-command API users that assign directly to the "argv"
member to use a strvec_pushv() of "args" instead.

In these cases it did not make sense to further refactor these
callers, e.g. daemon.c could be made to construct the arguments closer
to handle(), but that would require moving the construction from its
cmd_main() and pass "argv" through two intermediate functions.

It would be possible for a change like this to introduce a regression
if we were doing:

      cp.argv = argv;
      argv[1] = "foo";

And changed the code, as is being done here, to:

      strvec_pushv(&cp.args, argv);
      argv[1] = "foo";

But as viewing this change with the "-W" flag reveals none of these
functions modify variable that's being pushed afterwards in a way that
would introduce such a logic error.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-25 22:15:07 -08:00
Junio C Hamano
06355d72dc Merge branch 'ab/pkt-line-cleanup'
Code clean-up.

* ab/pkt-line-cleanup:
  pkt-line.[ch]: remove unused packet_read_line_buf()
  pkt-line.[ch]: remove unused packet_buf_write_len()
2021-10-25 16:07:00 -07:00
Ævar Arnfjörð Bjarmason
ec9a37d69b pkt-line.[ch]: remove unused packet_read_line_buf()
This function was added in 4981fe750b (pkt-line: share
buffer/descriptor reading implementation, 2013-02-23), but in
01f9ec64c8 (Use packet_reader instead of packet_read_line,
2018-12-29) the code that was using it was removed.

Since it's being removed we can in turn remove the "src" and "src_len"
arguments to packet_read(), all the remaining users just passed a
NULL/NULL pair to it.

That function is only a thin wrapper for packet_read_with_status()
which still needs those arguments, but for the thin packet_read()
convenience wrapper we can do away with it for now.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-15 13:09:40 -07:00
Ævar Arnfjörð Bjarmason
6e54a32468 daemon.c: refactor hostinfo_init() to HOSTINFO_INIT macro
Remove the hostinfo_init() function added in 01cec54e13 (daemon:
deglobalize hostname information, 2015-03-07) and instead initialize
the "struct hostinfo" with a macro.

This is the more idiomatic pattern in the codebase, and doesn't leave
us wondering when we see the *_init() function if this struct needs
more complex initialization than a macro can provide.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 15:02:32 -07:00
Junio C Hamano
bde35a2a93 Merge branch 'rs/daemon-sanitize-dir-sep'
"git daemon" has been tightened against systems that take backslash
as directory separator.

* rs/daemon-sanitize-dir-sep:
  daemon: sanitize all directory separators
2021-04-08 13:23:26 -07:00
René Scharfe
9a7f1ce8b7 daemon: sanitize all directory separators
When sanitizing client-supplied strings on Windows, also strip off
backslashes, not just slashes.

Signed-off-by: René Scharfe <l.s.r@web.de>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-26 22:00:12 -07:00
René Scharfe
ca56dadb4b use CALLOC_ARRAY
Add and apply a semantic patch for converting code that open-codes
CALLOC_ARRAY to use it instead.  It shortens the code and infers the
element size automatically.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-13 16:00:09 -08:00
Jeff King
d70a9eb611 strvec: rename struct fields
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>
2020-07-30 19:18:06 -07:00
Jeff King
f6d8942b1f strvec: fix indentation in renamed calls
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>
2020-07-28 15:02:18 -07:00
Jeff King
ef8d7ac42a strvec: convert more callers away from argv_array name
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>
2020-07-28 15:02:18 -07:00
Elijah Newren
15beaaa3d1 Fix spelling errors in code comments
Reported-by: Jens Schleusener <Jens.Schleusener@fossies.org>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-10 16:00:54 +09:00
Junio C Hamano
f9bcd751aa Merge branch 'lw/daemon-log-destination'
Recent introduction of "--log-destination" option to "git daemon"
did not work well when the daemon was run under "--inetd" mode.

* lw/daemon-log-destination:
  daemon.c: fix condition for redirecting stderr
2018-04-25 13:28:58 +09:00
Lucas Werkmeister
e67d906d73 daemon.c: fix condition for redirecting stderr
Since the --log-destination option was added in 0c591cacb ("daemon: add
--log-destination=(stderr|syslog|none)", 2018-02-04) with the explicit
goal of allowing logging to stderr when running in inetd mode, we should
not always redirect stderr to /dev/null in inetd mode, but rather only
when stderr is not being used for logging.

Signed-off-by: Lucas Werkmeister <mail@lucaswerkmeister.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-09 11:25:48 +09:00
Junio C Hamano
c2bd43d66d Merge branch 'lw/daemon-log-destination'
The log from "git daemon" can be redirected with a new option; one
relevant use case is to send the log to standard error (instead of
syslog) when running it from inetd.

* lw/daemon-log-destination:
  daemon: add --log-destination=(stderr|syslog|none)
2018-02-21 12:45:04 -08:00
Lucas Werkmeister
0c591cacba daemon: add --log-destination=(stderr|syslog|none)
This new option can be used to override the implicit --syslog of
--inetd, or to disable all logging. (While --detach also implies
--syslog, --log-destination=stderr with --detach is useless since
--detach disassociates the process from the original stderr.) --syslog
is retained as an alias for --log-destination=syslog.

--log-destination always overrides implicit --syslog regardless of
option order. This is different than the “last one wins” logic that
applies to some implicit options elsewhere in Git, but should hopefully
be less confusing. (I also don’t know if *all* implicit options in Git
follow “last one wins”.)

The combination of --inetd with --log-destination=stderr is useful, for
instance, when running `git daemon` as an instanced systemd service
(with associated socket unit). In this case, log messages sent via
syslog are received by the journal daemon, but run the risk of being
processed at a time when the `git daemon` process has already exited
(especially if the process was very short-lived, e.g. due to client
error), so that the journal daemon can no longer read its cgroup and
attach the message to the correct systemd unit (see systemd/systemd#2913
[1]). Logging to stderr instead can solve this problem, because systemd
can connect stderr directly to the journal daemon, which then already
knows which unit is associated with this stream.

[1]: https://github.com/systemd/systemd/issues/2913

Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Lucas Werkmeister <mail@lucaswerkmeister.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-05 10:30:44 -08:00
Jeff King
ed15e58efe daemon: fix length computation in newline stripping
When git-daemon gets a pktline request, we strip off any
trailing newline, replacing it with a NUL. Clients prior to
5ad312bede (in git v1.4.0) would send:

  git-upload-pack repo.git\n

and we need to strip it off to understand their request.
After 5ad312bede, we send the host attribute but no newline,
like:

  git-upload-pack repo.git\0host=example.com\0

Both of these are parsed correctly by git-daemon. But if
some client were to combine the two:

  git-upload-pack repo.git\n\0host=example.com\0

we don't parse it correctly. The problem is that we use the
"len" variable to record the position of the NUL separator,
but then decrement it when we strip the newline. So we start
with:

  git-upload-pack repo.git\n\0host=example.com\0
                             ^-- len

and end up with:

  git-upload-pack repo.git\0\0host=example.com\0
                           ^-- len

This is arguably correct, since "len" tells us the length of
the initial string, but we don't actually use it for that.
What we do use it for is finding the offset of the extended
attributes; they used to be at len+1, but are now at len+2.

We can solve that by just leaving "len" where it is. We
don't have to care about the length of the shortened string,
since we just treat it like a C string.

No version of Git ever produced such a string, but it seems
like the daemon code meant to handle this case (and it seems
like a reasonable thing for somebody to do in a 3rd-party
implementation).

Reported-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-01-25 13:50:17 -08:00
Jeff King
550fbcad1c daemon: handle NULs in extended attribute string
If we receive a request with extended attributes after the
NUL, we try to write those attributes to the log. We do so
with a "%s" format specifier, which will only show
characters up to the first NUL.

That's enough for printing a "host=" specifier. But since
dfe422d04d (daemon: recognize hidden request arguments,
2017-10-16) we may have another NUL, followed by protocol
parameters, and those are not logged at all.

Let's cut out the attempt to show the whole string, and
instead log when we parse individual attributes. We could
leave the "extended attributes (%d bytes) exist" part of the
log, which in theory could alert us to attributes that fail
to parse. But anything we don't parse as a "host=" parameter
gets blindly added to the "protocol" attribute, so we'd see
it in that part of the log.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-01-25 13:50:17 -08:00
Jeff King
19136be3f8 daemon: fix off-by-one in logging extended attributes
If receive a request like:

  git-upload-pack /foo.git\0host=localhost

we mark the offset of the NUL byte as "len", and then log
the bytes after the NUL with a "%.*s" placeholder, using
"pktlen - len" as the length, and "line + len + 1" as the
start of the string.

This is off-by-one, since the start of the string skips past
the separating NUL byte, but the adjusted length includes
it. Fortunately this doesn't actually read past the end of
the buffer, since "%.*s" will stop when it hits a NUL. And
regardless of what is in the buffer, packet_read() will
always add an extra NUL terminator for safety.

As an aside, the git.git client sends an extra NUL after a
"host" field, too, so we'd generally hit that one first, not
the one added by packet_read(). You can see this in the test
output which reports 15 bytes, even though the string has
only 14 bytes of visible data. But the point is that even a
client sending unusual data could not get us to read past
the end of the buffer, so this is purely a cosmetic fix.

Reported-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-01-25 13:50:17 -08:00
Brandon Williams
dfe422d04d daemon: recognize hidden request arguments
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 teach git-daemon 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.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-17 10:51:29 +09:00
Brandon Williams
b2141fc1d2 config: don't include config.h by default
Stop including config.h by default in cache.h.  Instead only include
config.h in those files which require use of the config system.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-15 12:56:22 -07:00
Junio C Hamano
5938454cbc Merge branch 'dt/xgethostname-nul-termination'
gethostname(2) may not NUL terminate the buffer if hostname does
not fit; unfortunately there is no easy way to see if our buffer
was too small, but at least this will make sure we will not end up
using garbage past the end of the buffer.

* dt/xgethostname-nul-termination:
  xgethostname: handle long hostnames
  use HOST_NAME_MAX to size buffers for gethostname(2)
2017-04-23 22:07:57 -07:00
René Scharfe
da25bdb776 use HOST_NAME_MAX to size buffers for gethostname(2)
POSIX limits the length of host names to HOST_NAME_MAX.  Export the
fallback definition from daemon.c and use this constant to make all
buffers used with gethostname(2) big enough for any possible result
and a terminating NUL.

Inspired-by: David Turner <dturner@twosigma.com>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: David Turner <dturner@twosigma.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-18 19:57:41 -07:00
Jeff King
6a97da3964 daemon: use an argv_array to exec children
Our struct child_process already has its own argv_array.
Let's use that to avoid having to format options into
separate buffers.

Note that we'll need to declare the child process outside of
the run_service_command() helper to do this. But that opens
up a further simplification, which is that the helper can
append to our argument list, saving each caller from
specifying "." manually.

Signed-off-by: Jeff King <peff@peff.net>
2017-03-30 14:59:50 -07:00
Junio C Hamano
aa22ef8a80 Merge branch 'jk/daemon-path-ok-check-truncation' into maint
"git daemon" used fixed-length buffers to turn URL to the
repository the client asked for into the server side directory
path, using snprintf() to avoid overflowing these buffers, but
allowed possibly truncated paths to the directory.  This has been
tightened to reject such a request that causes overlong path to be
required to serve.

* jk/daemon-path-ok-check-truncation:
  daemon: detect and reject too-long paths
2016-11-29 13:27:56 -08:00
Junio C Hamano
dbaa6bdce2 Merge branch 'ls/filter-process'
The smudge/clean filter API expect an external process is spawned
to filter the contents for each path that has a filter defined.  A
new type of "process" filter API has been added to allow the first
request to run the filter for a path to spawn a single process, and
all filtering need is served by this single process for multiple
paths, reducing the process creation overhead.

* ls/filter-process:
  contrib/long-running-filter: add long running filter example
  convert: add filter.<driver>.process option
  convert: prepare filter.<driver>.process option
  convert: make apply_filter() adhere to standard Git error handling
  pkt-line: add functions to read/write flush terminated packet streams
  pkt-line: add packet_write_gently()
  pkt-line: add packet_flush_gently()
  pkt-line: add packet_write_fmt_gently()
  pkt-line: extract set_packet_header()
  pkt-line: rename packet_write() to packet_write_fmt()
  run-command: add clean_on_exit_handler
  run-command: move check_pipe() from write_or_die to run_command
  convert: modernize tests
  convert: quote filter names in error messages
2016-10-31 13:15:21 -07:00
Junio C Hamano
ee87d47b36 Merge branch 'jk/daemon-path-ok-check-truncation'
"git daemon" used fixed-length buffers to turn URL to the
repository the client asked for into the server side directory
path, using snprintf() to avoid overflowing these buffers, but
allowed possibly truncated paths to the directory.  This has been
tightened to reject such a request that causes overlong path to be
required to serve.

* jk/daemon-path-ok-check-truncation:
  daemon: detect and reject too-long paths
2016-10-27 14:58:50 -07:00
Jeff King
6bdb0083be daemon: detect and reject too-long paths
When we are checking the path via path_ok(), we use some
fixed PATH_MAX buffers. We write into them via snprintf(),
so there's no possibility of overflow, but it does mean we
may silently truncate the path, leading to potentially
confusing errors when the partial path does not exist.

We're better off to reject the path explicitly.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-24 09:59:29 -07:00
Lars Schneider
81c634e94f pkt-line: rename packet_write() to packet_write_fmt()
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>
2016-10-17 11:36:50 -07:00
Junio C Hamano
faacc8efe5 Merge branch 'jk/common-main' into maint
There are certain house-keeping tasks that need to be performed at
the very beginning of any Git program, and programs that are not
built-in commands had to do them exactly the same way as "git"
potty does.  It was easy to make mistakes in one-off standalone
programs (like test helpers).  A common "main()" function that
calls cmd_main() of individual program has been introduced to
make it harder to make mistakes.

* jk/common-main:
  mingw: declare main()'s argv as const
  common-main: call git_setup_gettext()
  common-main: call restore_sigpipe_to_default()
  common-main: call sanitize_stdfds()
  common-main: call git_extract_argv0_path()
  add an extra level of indirection to main()
2016-09-08 21:35:51 -07:00
Junio C Hamano
b48dfd86c9 Merge branch 'ew/daemon-socket-keepalive'
Recent update to "git daemon" tries to enable the socket-level
KEEPALIVE, but when it is spawned via inetd, the standard input
file descriptor may not necessarily be connected to a socket.
Suppress an ENOTSOCK error from setsockopt().

* ew/daemon-socket-keepalive:
  Windows: add missing definition of ENOTSOCK
  daemon: ignore ENOTSOCK from setsockopt
2016-07-28 10:34:43 -07:00
Junio C Hamano
d4c6375fd8 Merge branch 'jk/common-main'
There are certain house-keeping tasks that need to be performed at
the very beginning of any Git program, and programs that are not
built-in commands had to do them exactly the same way as "git"
potty does.  It was easy to make mistakes in one-off standalone
programs (like test helpers).  A common "main()" function that
calls cmd_main() of individual program has been introduced to
make it harder to make mistakes.

* jk/common-main:
  mingw: declare main()'s argv as const
  common-main: call git_setup_gettext()
  common-main: call restore_sigpipe_to_default()
  common-main: call sanitize_stdfds()
  common-main: call git_extract_argv0_path()
  add an extra level of indirection to main()
2016-07-19 13:22:19 -07:00
Eric Wong
49c58d86ce daemon: ignore ENOTSOCK from setsockopt
In inetd mode, we are not guaranteed stdin or stdout is a
socket; callers could filter the data through a pipe
or be testing with regular files.

This prevents t5802 from polluting syslog.

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-18 11:09:52 -07:00
Jeff King
5ce5f5fa5a common-main: call git_setup_gettext()
This should be part of every program, as otherwise users do
not get translated error messages. However, some external
commands forgot to do so (e.g., git-credential-store). This
fixes them, and eliminates the repeated code in programs
that did remember to use it.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 15:09:10 -07:00
Jeff King
57f5d52a94 common-main: call sanitize_stdfds()
This is setup that should be done in every program for
safety, but we never got around to adding it everywhere (so
builtins benefited from the call in git.c, but any external
commands did not). Putting it in the common main() gives us
this safety everywhere.

Note that the case in daemon.c is a little funny. We wait
until we know whether we want to daemonize, and then either:

 - call daemonize(), which will close stdio and reopen it to
   /dev/null under the hood

 - sanitize_stdfds(), to fix up any odd cases

But that is way too late; the point of sanitizing is to give
us reliable descriptors on 0/1/2, and we will already have
executed code, possibly called die(), etc. The sanitizing
should be the very first thing that happens.

With this patch, git-daemon will sanitize first, and can
remove the call in the non-daemonize case. It does mean that
daemonize() may just end up closing the descriptors we
opened, but that's not a big deal (it's not wrong to do so,
nor is it really less optimal than the case where our parent
process redirected us from /dev/null ahead of time).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 15:09:10 -07:00
Jeff King
650c449250 common-main: call git_extract_argv0_path()
Every program which links against libgit.a must call this
function, or risk hitting an assert() in system_path() that
checks whether we have configured argv0_path (though only
when RUNTIME_PREFIX is defined, so essentially only on
Windows).

Looking at the diff, you can see that putting it into the
common main() saves us having to do it individually in each
of the external commands. But what you can't see are the
cases where we _should_ have been doing so, but weren't
(e.g., git-credential-store, and all of the t/helper test
programs).

This has been an accident-waiting-to-happen for a long time,
but wasn't triggered until recently because it involves one
of those programs actually calling system_path(). That
happened with git-credential-store in v2.8.0 with ae5f677
(lazily load core.sharedrepository, 2016-03-11). The
program:

  - takes a lock file, which...

  - opens a tempfile, which...

  - calls adjust_shared_perm to fix permissions, which...

  - lazy-loads the config (as of ae5f677), which...

  - calls system_path() to find the location of
    /etc/gitconfig

On systems with RUNTIME_PREFIX, this means credential-store
reliably hits that assert() and cannot be used.

We never noticed in the test suite, because we set
GIT_CONFIG_NOSYSTEM there, which skips the system_path()
lookup entirely.  But if we were to tweak git_config() to
find /etc/gitconfig even when we aren't going to open it,
then the test suite shows multiple failures (for
credential-store, and for some other test helpers). I didn't
include that tweak here because it's way too specific to
this particular call to be worth carrying around what is
essentially dead code.

The implementation is fairly straightforward, with one
exception: there is exactly one caller (git.c) that actually
cares about the result of the function, and not the
side-effect of setting up argv0_path. We can accommodate
that by simply replacing the value of argv[0] in the array
we hand down to cmd_main().

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 15:09:10 -07:00
Jeff King
3f2e2297b9 add an extra level of indirection to main()
There are certain startup tasks that we expect every git
process to do. In some cases this is just to improve the
quality of the program (e.g., setting up gettext()). In
others it is a requirement for using certain functions in
libgit.a (e.g., system_path() expects that you have called
git_extract_argv0_path()).

Most commands are builtins and are covered by the git.c
version of main(). However, there are still a few external
commands that use their own main(). Each of these has to
remember to include the correct startup sequence, and we are
not always consistent.

Rather than just fix the inconsistencies, let's make this
harder to get wrong by providing a common main() that can
run this standard startup.

We basically have two options to do this:

 - the compat/mingw.h file already does something like this by
   adding a #define that replaces the definition of main with a
   wrapper that calls mingw_startup().

   The upside is that the code in each program doesn't need
   to be changed at all; it's rewritten on the fly by the
   preprocessor.

   The downside is that it may make debugging of the startup
   sequence a bit more confusing, as the preprocessor is
   quietly inserting new code.

 - the builtin functions are all of the form cmd_foo(),
   and git.c's main() calls them.

   This is much more explicit, which may make things more
   obvious to somebody reading the code. It's also more
   flexible (because of course we have to figure out _which_
   cmd_foo() to call).

   The downside is that each of the builtins must define
   cmd_foo(), instead of just main().

This patch chooses the latter option, preferring the more
explicit approach, even though it is more invasive. We
introduce a new file common-main.c, with the "real" main. It
expects to call cmd_main() from whatever other objects it is
linked against.

We link common-main.o against anything that links against
libgit.a, since we know that such programs will need to do
this setup. Note that common-main.o can't actually go inside
libgit.a, as the linker would not pick up its main()
function automatically (it has no callers).

The rest of the patch is just adjusting all of the various
external programs (mostly in t/helper) to use cmd_main().
I've provided a global declaration for cmd_main(), which
means that all of the programs also need to match its
signature. In particular, many functions need to switch to
"const char **" instead of "char **" for argv. This effect
ripples out to a few other variables and functions, as well.

This makes the patch even more invasive, but the end result
is much better. We should be treating argv strings as const
anyway, and now all programs conform to the same signature
(which also matches the way builtins are defined).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 15:09:10 -07:00
Eric Wong
a43b68a196 daemon: enable SO_KEEPALIVE for all sockets
While --init-timeout and --timeout options exist and I've never
run git-daemon without them, some users may forget to set them
and encounter hung daemon processes when connections fail.
Enable socket-level timeouts so the kernel can send keepalive
probes as necessary to detect failed connections.

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-05-25 09:42:53 -07:00
Junio C Hamano
11529ecec9 Merge branch 'jk/tighten-alloc'
Update various codepaths to avoid manually-counted malloc().

* jk/tighten-alloc: (22 commits)
  ewah: convert to REALLOC_ARRAY, etc
  convert ewah/bitmap code to use xmalloc
  diff_populate_gitlink: use a strbuf
  transport_anonymize_url: use xstrfmt
  git-compat-util: drop mempcpy compat code
  sequencer: simplify memory allocation of get_message
  test-path-utils: fix normalize_path_copy output buffer size
  fetch-pack: simplify add_sought_entry
  fast-import: simplify allocation in start_packfile
  write_untracked_extension: use FLEX_ALLOC helper
  prepare_{git,shell}_cmd: use argv_array
  use st_add and st_mult for allocation size computation
  convert trivial cases to FLEX_ARRAY macros
  use xmallocz to avoid size arithmetic
  convert trivial cases to ALLOC_ARRAY
  convert manual allocations to argv_array
  argv-array: add detach function
  add helpers for allocating flex-array structs
  harden REALLOC_ARRAY and xcalloc against size_t overflow
  tree-diff: catch integer overflow in combine_diff_path allocation
  ...
2016-02-26 13:37:16 -08:00
Jeff King
850d2fec53 convert manual allocations to argv_array
There are many manual argv allocations that predate the
argv_array API. Switching to that API brings a few
advantages:

  1. We no longer have to manually compute the correct final
     array size (so it's one less thing we can screw up).

  2. In many cases we had to make a separate pass to count,
     then allocate, then fill in the array. Now we can do it
     in one pass, making the code shorter and easier to
     follow.

  3. argv_array handles memory ownership for us, making it
     more obvious when things should be free()d and and when
     not.

Most of these cases are pretty straightforward. In some, we
switch from "run_command_v" to "run_command" which lets us
directly use the argv_array embedded in "struct
child_process".

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-22 14:50:32 -08:00
Junio C Hamano
8f309aeb82 strbuf: introduce strbuf_getline_{lf,nul}()
The strbuf_getline() interface allows a byte other than LF or NUL as
the line terminator, but this is only because I wrote these
codepaths anticipating that there might be a value other than NUL
and LF that could be useful when I introduced line_termination long
time ago.  No useful caller that uses other value has emerged.

By now, it is clear that the interface is overly broad without a
good reason.  Many codepaths have hardcoded preference to read
either LF terminated or NUL terminated records from their input, and
then call strbuf_getline() with LF or NUL as the third parameter.

This step introduces two thin wrappers around strbuf_getline(),
namely, strbuf_getline_lf() and strbuf_getline_nul(), and
mechanically rewrites these call sites to call either one of
them.  The changes contained in this patch are:

 * introduction of these two functions in strbuf.[ch]

 * mechanical conversion of all callers to strbuf_getline() with
   either '\n' or '\0' as the third parameter to instead call the
   respective thin wrapper.

After this step, output from "git grep 'strbuf_getline('" would
become a lot smaller.  An interim goal of this series is to make
this an empty set, so that we can have strbuf_getline_crlf() take
over the shorter name strbuf_getline().

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-01-15 10:12:51 -08:00
Junio C Hamano
c3c592ef95 Merge branch 'rs/daemon-plug-child-leak'
"git daemon" uses "run_command()" without "finish_command()", so it
needs to release resources itself, which it forgot to do.

* rs/daemon-plug-child-leak:
  daemon: plug memory leak
  run-command: factor out child_process_clear()
2015-11-03 15:13:12 -08:00
René Scharfe
b1b49ff8d4 daemon: plug memory leak
Call child_process_clear() when a child ends to release the memory
allocated for its environment.  This is necessary because unlike all
other users of start_command() we don't call finish_command(), which
would have taken care of that for us.

This leak was introduced by f063d38b (daemon: use cld->env_array
when re-spawning).

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-11-02 15:01:23 -08:00
Jeff King
f063d38b80 daemon: use cld->env_array when re-spawning
This avoids an ugly strcat into a fixed-size buffer. It's
not wrong (the buffer is plenty large enough for an IPv6
address plus some minor formatting), but it takes some
effort to verify that.

Unfortunately we are still stuck with some fixed-size
buffers to hold the output of inet_ntop. But at least we now
pass very easy-to-verify parameters, rather than doing a
manual computation to account for other data in the buffer.

As a side effect, this also fixes the case where we might
pass an uninitialized portbuf buffer through the
environment. This probably couldn't happen in practice, as
it would mean that addr->sa_family was neither AF_INET nor
AF_INET6 (and that is all we are listening on).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-10-05 11:08:05 -07:00
Jeff King
5096d4909f convert trivial sprintf / strcpy calls to xsnprintf
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>
2015-09-25 10:18:18 -07:00
Junio C Hamano
1f76a10b2d write_file(): drop caller-supplied LF from calls to create a one-liner file
All of the callsites covered by this change call write_file() or
write_file_gently() to create a one-liner file.  Drop the caller
supplied LF and let these callees to append it as necessary.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-25 12:49:19 -07:00
Junio C Hamano
12d6ce1dba write_file(): drop "fatal" parameter
All callers except three passed 1 for the "fatal" parameter to ask
this function to die upon error, but to a casual reader of the code,
it was not all obvious what that 1 meant.  Instead, split the
function into two based on a common write_file_v() that takes the
flag, introduce write_file_gently() as a new way to attempt creating
a file without dying on error, and make three callers to call it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-24 13:09:02 -07:00
Junio C Hamano
9e4d2f6d45 Merge branch 'jc/daemon-no-ipv6-for-2.4.1'
"git daemon" fails to build from the source under NO_IPV6
configuration (regression in 2.4).

* jc/daemon-no-ipv6-for-2.4.1:
  daemon: unbreak NO_IPV6 build regression
2015-05-11 14:23:53 -07:00