Commit 20f66485 authored by Ulrich Müller's avatar Ulrich Müller
Browse files

Allow update-game-score to run sgid instead of suid.

* configure.ac (gamegroup): New AC_SUBST.
(--with-gameuser): Allow to specify a group instead of a user.
In the default case, check at configure time if a 'games' user
exists.
* lib-src/update-game-score.c: Allow the program to run sgid
instead of suid, in order to match common practice for most games.
(main): Check if we are running sgid.  Pass appropriate file
permission bits to 'write_scores'.
(write_scores): New 'mode' argument, instead of hardcoding 0644.
(get_prefix): Update error message.
* lib-src/Makefile.in (gamegroup): New variable, set by configure.
($(DESTDIR)${archlibdir}): Handle both suid or sgid when
installing the 'update-game-score' program.
* lisp/play/gamegrid.el (gamegrid-add-score-with-update-game-score):
Allow the 'update-game-score' helper program to run suid or sgid.
parent 59e7fe6d
2015-01-21 Ulrich Müller <ulm@gentoo.org>
* configure.ac (gamegroup): New AC_SUBST.
(--with-gameuser): Allow to specify a group instead of a user.
In the default case, check at configure time if a 'games' user
exists.
2015-01-16 Paul Eggert <eggert@cs.ucla.edu>
Give up on -Wsuggest-attribute=const
......
......@@ -392,10 +392,25 @@ OPTION_DEFAULT_ON([compress-install],
make GZIP_PROG= install])
AC_ARG_WITH(gameuser,dnl
[AS_HELP_STRING([--with-gameuser=USER],[user for shared game score files])])
test "X${with_gameuser}" != X && test "${with_gameuser}" != yes \
&& gameuser="${with_gameuser}"
test "X$gameuser" = X && gameuser=games
[AS_HELP_STRING([--with-gameuser=USER_OR_GROUP],
[user for shared game score files.
An argument prefixed by ':' specifies a group instead.])])
gameuser=
gamegroup=
case ${with_gameuser} in
no) ;;
"" | yes)
AC_MSG_CHECKING([whether a 'games' user exists])
if id -u games >/dev/null 2>&1; then
AC_MSG_RESULT([yes])
gameuser=games
else
AC_MSG_RESULT([no])
fi
;;
:*) gamegroup=`echo "${with_gameuser}" | sed -e "s/://"` ;;
*) gameuser=${with_gameuser} ;;
esac
AC_ARG_WITH([gnustep-conf],dnl
[AS_HELP_STRING([--with-gnustep-conf=FILENAME],
......@@ -4684,6 +4699,7 @@ AC_SUBST(etcdocdir)
AC_SUBST(bitmapdir)
AC_SUBST(gamedir)
AC_SUBST(gameuser)
AC_SUBST(gamegroup)
## FIXME? Nothing uses @LD_SWITCH_X_SITE@.
## src/Makefile.in did add LD_SWITCH_X_SITE (as a cpp define) to the
## end of LIBX_BASE, but nothing ever set it.
......
......@@ -45,6 +45,13 @@ and silent rules are now quieter. To get the old behavior where
'make' chatters a lot, configure with '--disable-silent-rules' or
build with 'make V=1'.
---
** The configure option '--with-gameuser' now allows to specify a
group instead of a user if its argument is prefixed by ':' (a colon).
This will cause the game score files in ${localstatedir}/games/emacs
to be owned by that group, and the helper program for updating them to
be installed setgid.
---
** The `grep-changelog' script (and its manual page) are no longer included.
It has no particular connection to Emacs and has not changed in years,
......
2015-01-21 Ulrich Müller <ulm@gentoo.org>
* update-game-score.c: Allow the program to run sgid instead
of suid, in order to match common practice for most games.
(main): Check if we are running sgid. Pass appropriate file
permission bits to 'write_scores'.
(write_scores): New 'mode' argument, instead of hardcoding 0644.
(get_prefix): Update error message.
* Makefile.in (gamegroup): New variable, set by configure.
($(DESTDIR)${archlibdir}): Handle both suid or sgid when
installing the 'update-game-score' program.
2015-01-16 Eli Zaretskii <eliz@gnu.org>
* Makefile.in (AM_V_RC, am__v_RC_, am__v_RC_0, am__v_RC_1): New
......
......@@ -122,6 +122,7 @@ archlibdir=@archlibdir@
gamedir=@gamedir@
gameuser=@gameuser@
gamegroup=@gamegroup@
# ==================== Utility Programs for the Build =================
......@@ -263,10 +264,17 @@ $(DESTDIR)${archlibdir}: all
umask 022; ${MKDIR_P} "$(DESTDIR)${gamedir}"; \
touch "$(DESTDIR)${gamedir}/snake-scores"; \
touch "$(DESTDIR)${gamedir}/tetris-scores"
-if chown ${gameuser} "$(DESTDIR)${archlibdir}/update-game-score${EXEEXT}" && chmod u+s "$(DESTDIR)${archlibdir}/update-game-score${EXEEXT}"; then \
chown ${gameuser} "$(DESTDIR)${gamedir}"; \
chmod u=rwx,g=rwx,o=rx "$(DESTDIR)${gamedir}"; \
fi
ifneq ($(gameuser),)
chown ${gameuser} "$(DESTDIR)${archlibdir}/update-game-score${EXEEXT}"
chmod u+s,go-r "$(DESTDIR)${archlibdir}/update-game-score${EXEEXT}"
chown ${gameuser} "$(DESTDIR)${gamedir}"
chmod u=rwx,g=rx,o=rx "$(DESTDIR)${gamedir}"
else ifneq ($(gamegroup),)
chgrp ${gamegroup} "$(DESTDIR)${archlibdir}/update-game-score${EXEEXT}"
chmod g+s,o-r "$(DESTDIR)${archlibdir}/update-game-score${EXEEXT}"
chgrp ${gamegroup} "$(DESTDIR)${gamedir}"
chmod u=rwx,g=rwx,o=rx "$(DESTDIR)${gamedir}"
endif
exp_archlibdir=`cd "$(DESTDIR)${archlibdir}" && /bin/pwd`; \
if [ "$$exp_archlibdir" != "`cd ${srcdir} && /bin/pwd`" ]; then \
for file in ${SCRIPTS}; do \
......
......@@ -21,8 +21,8 @@ along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
/* This program allows a game to securely and atomically update a
score file. It should be installed setuid, owned by an appropriate
user like `games'.
score file. It should be installed either setuid or setgid, owned
by an appropriate user or group like `games'.
Alternatively, it can be compiled without HAVE_SHARED_GAME_DIR
defined, and in that case it will store scores in the user's home
......@@ -88,7 +88,7 @@ static int push_score (struct score_entry **scores, ptrdiff_t *count,
ptrdiff_t *size, struct score_entry const *newscore);
static void sort_scores (struct score_entry *scores, ptrdiff_t count,
bool reverse);
static int write_scores (const char *filename,
static int write_scores (const char *filename, mode_t mode,
const struct score_entry *scores, ptrdiff_t count);
static _Noreturn void
......@@ -122,18 +122,19 @@ get_user_id (void)
}
static const char *
get_prefix (bool running_suid, const char *user_prefix)
get_prefix (bool privileged, const char *user_prefix)
{
if (!running_suid && user_prefix == NULL)
lose ("Not using a shared game directory, and no prefix given.");
if (running_suid)
if (privileged)
{
#ifdef HAVE_SHARED_GAME_DIR
return HAVE_SHARED_GAME_DIR;
#else
lose ("This program was compiled without HAVE_SHARED_GAME_DIR,\n and should not be suid.");
lose ("This program was compiled without HAVE_SHARED_GAME_DIR,\n"
"and should not run with elevated privileges.");
#endif
}
if (user_prefix == NULL)
lose ("Not using a shared game directory, and no prefix given.");
return user_prefix;
}
......@@ -173,7 +174,7 @@ int
main (int argc, char **argv)
{
int c;
bool running_suid;
bool running_suid, running_sgid;
void *lockstate;
char *scorefile;
char *end, *nl, *user, *data;
......@@ -214,8 +215,11 @@ main (int argc, char **argv)
usage (EXIT_FAILURE);
running_suid = (getuid () != geteuid ());
running_sgid = (getgid () != getegid ());
if (running_suid && running_sgid)
lose ("This program can run either suid or sgid, but not both.");
prefix = get_prefix (running_suid, user_prefix);
prefix = get_prefix (running_suid || running_sgid, user_prefix);
scorefile = malloc (strlen (prefix) + strlen (argv[optind]) + 2);
if (!scorefile)
......@@ -270,7 +274,8 @@ main (int argc, char **argv)
scores += scorecount - max_scores;
scorecount = max_scores;
}
if (write_scores (scorefile, scores, scorecount) < 0)
if (write_scores (scorefile, running_sgid ? 0664 : 0644,
scores, scorecount) < 0)
{
unlock_file (scorefile, lockstate);
lose_syserr ("Failed to write scores file");
......@@ -421,8 +426,8 @@ sort_scores (struct score_entry *scores, ptrdiff_t count, bool reverse)
}
static int
write_scores (const char *filename, const struct score_entry *scores,
ptrdiff_t count)
write_scores (const char *filename, mode_t mode,
const struct score_entry *scores, ptrdiff_t count)
{
int fd;
FILE *f;
......@@ -435,7 +440,7 @@ write_scores (const char *filename, const struct score_entry *scores,
if (fd < 0)
return -1;
#ifndef DOS_NT
if (fchmod (fd, 0644) != 0)
if (fchmod (fd, mode) != 0)
return -1;
#endif
f = fdopen (fd, "w");
......
2015-01-21 Ulrich Müller <ulm@gentoo.org>
* play/gamegrid.el (gamegrid-add-score-with-update-game-score):
Allow the 'update-game-score' helper program to run suid or sgid.
2015-01-21 Stefan Monnier <monnier@iro.umontreal.ca>
 
* emacs-lisp/eieio.el: Use cl-defmethod.
......
......@@ -486,13 +486,13 @@ FILE is created there."
(not (zerop (logand (file-modes
(expand-file-name "update-game-score"
exec-directory))
#o4000)))))
#o6000)))))
(cond ((file-name-absolute-p file)
(gamegrid-add-score-insecure file score))
((and gamegrid-shared-game-dir
(file-exists-p (expand-file-name file shared-game-score-directory)))
;; Use the setuid "update-game-score" program to update a
;; system-wide score file.
;; Use the setuid (or setgid) "update-game-score" program
;; to update a system-wide score file.
(gamegrid-add-score-with-update-game-score-1 file
(expand-file-name file shared-game-score-directory) score))
;; Else: Add the score to a score file in the user's home
......
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