Revision 3ec804490a265f4c418a321428c12f3f18b7eff5 authored by Jeff King on 29 April 2017, 12:36:44 UTC, committed by Junio C Hamano on 05 May 2017, 03:07:27 UTC
When a remote server uses git-shell, the client side will
connect to it like:
ssh server "git-upload-pack 'foo.git'"
and we literally exec ("git-upload-pack", "foo.git"). In
early versions of upload-pack and receive-pack, we took a
repository argument and nothing else. But over time they
learned to accept dashed options. If the user passes a
repository name that starts with a dash, the results are
confusing at best (we complain of a bogus option instead of
a non-existent repository) and malicious at worst (the user
can start an interactive pager via "--help").
We could pass "--" to the sub-process to make sure the
user's argument is interpreted as a branch name. I.e.:
git-upload-pack -- -foo.git
But adding "--" automatically would make us inconsistent
with a normal shell (i.e., when git-shell is not in use),
where "-foo.git" would still be an error. For that case, the
client would have to specify the "--", but they can't do so
reliably, as existing versions of git-shell do not allow
more than a single argument.
The simplest thing is to simply disallow "-" at the start of
the repo name argument. This hasn't worked either with or
without git-shell since version 1.0.0, and nobody has
complained.
Note that this patch just applies to do_generic_cmd(), which
runs upload-pack, receive-pack, and upload-archive. There
are two other types of commands that git-shell runs:
- do_cvs_cmd(), but this already restricts the argument to
be the literal string "server"
- admin-provided commands in the git-shell-commands
directory. We'll pass along arbitrary arguments there,
so these commands could have similar problems. But these
commands might actually understand dashed arguments, so
we cannot just block them here. It's up to the writer of
the commands to make sure they are safe. With great
power comes great responsibility.
Reported-by: Timo Schmid <tschmid@ernw.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 7654286
git-pack-refs.txt
git-pack-refs(1)
================
NAME
----
git-pack-refs - Pack heads and tags for efficient repository access
SYNOPSIS
--------
[verse]
'git pack-refs' [--all] [--no-prune]
DESCRIPTION
-----------
Traditionally, tips of branches and tags (collectively known as
'refs') were stored one file per ref in a (sub)directory
under `$GIT_DIR/refs`
directory. While many branch tips tend to be updated often,
most tags and some branch tips are never updated. When a
repository has hundreds or thousands of tags, this
one-file-per-ref format both wastes storage and hurts
performance.
This command is used to solve the storage and performance
problem by storing the refs in a single file,
`$GIT_DIR/packed-refs`. When a ref is missing from the
traditional `$GIT_DIR/refs` directory hierarchy, it is looked
up in this
file and used if found.
Subsequent updates to branches always create new files under
`$GIT_DIR/refs` directory hierarchy.
A recommended practice to deal with a repository with too many
refs is to pack its refs with `--all` once, and
occasionally run `git pack-refs`. Tags are by
definition stationary and are not expected to change. Branch
heads will be packed with the initial `pack-refs --all`, but
only the currently active branch heads will become unpacked,
and the next `pack-refs` (without `--all`) will leave them
unpacked.
OPTIONS
-------
--all::
The command by default packs all tags and refs that are already
packed, and leaves other refs
alone. This is because branches are expected to be actively
developed and packing their tips does not help performance.
This option causes branch tips to be packed as well. Useful for
a repository with many branches of historical interests.
--no-prune::
The command usually removes loose refs under `$GIT_DIR/refs`
hierarchy after packing them. This option tells it not to.
BUGS
----
Older documentation written before the packed-refs mechanism was
introduced may still say things like ".git/refs/heads/<branch> file
exists" when it means "branch <branch> exists".
GIT
---
Part of the linkgit:git[1] suite
Computing file changes ...
