Skip to content

Commit 81af418

Browse files
nmischnmisch
committed
Diagnose incompatible OpenLDAP versions during build and test.
With OpenLDAP versions 2.4.24 through 2.4.31, inclusive, PostgreSQL backends can crash at exit. Raise a warning during "configure" based on the compile-time OpenLDAP version number, and test the crash scenario in the dblink test suite. Back-patch to 9.0 (all supported versions).
1 parent 124331b commit 81af418

File tree

11 files changed

+236
-1
lines changed

11 files changed

+236
-1
lines changed

‎configure‎

Lines changed: 77 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -13796,6 +13796,17 @@ fi
1379613796

1379713797
fi
1379813798

13799+
# PGAC_LDAP_SAFE
13800+
# --------------
13801+
# PostgreSQL sometimes loads libldap_r and plain libldap into the same
13802+
# process. Check for OpenLDAP versions known not to tolerate doing so; assume
13803+
# non-OpenLDAP implementations are safe. The dblink test suite exercises the
13804+
# hazardous interaction directly.
13805+
13806+
13807+
13808+
13809+
1379913810
if test "$with_ldap" = yes ; then
1380013811
if test "$PORTNAME" != "win32"; then
1380113812

@@ -13953,6 +13964,72 @@ fi
1395313964

1395413965
done
1395513966

13967+
{ $as_echo "$as_me:$LINENO: checking for compatible LDAP implementation" >&5
13968+
$as_echo_n "checking for compatible LDAP implementation... " >&6; }
13969+
if test "${pgac_cv_ldap_safe+set}" = set; then
13970+
$as_echo_n "(cached) " >&6
13971+
else
13972+
cat >conftest.$ac_ext <<_ACEOF
13973+
/* confdefs.h. */
13974+
_ACEOF
13975+
cat confdefs.h >>conftest.$ac_ext
13976+
cat >>conftest.$ac_ext <<_ACEOF
13977+
/* end confdefs.h. */
13978+
#include <ldap.h>
13979+
#if !defined(LDAP_VENDOR_VERSION) || \
13980+
(defined(LDAP_API_FEATURE_X_OPENLDAP) && \
13981+
LDAP_VENDOR_VERSION >= 20424 && LDAP_VENDOR_VERSION <= 20431)
13982+
choke me
13983+
#endif
13984+
int
13985+
main ()
13986+
{
13987+
13988+
;
13989+
return 0;
13990+
}
13991+
_ACEOF
13992+
rm -f conftest.$ac_objext
13993+
if { (ac_try="$ac_compile"
13994+
case "(($ac_try" in
13995+
*\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
13996+
*) ac_try_echo=$ac_try;;
13997+
esac
13998+
eval ac_try_echo="\"\$as_me:$LINENO: $ac_try_echo\""
13999+
$as_echo "$ac_try_echo") >&5
14000+
(eval "$ac_compile") 2>conftest.er1
14001+
ac_status=$?
14002+
grep -v '^ *+' conftest.er1 >conftest.err
14003+
rm -f conftest.er1
14004+
cat conftest.err >&5
14005+
$as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
14006+
(exit $ac_status); } && {
14007+
test -z "$ac_c_werror_flag" ||
14008+
test ! -s conftest.err
14009+
} && test -s conftest.$ac_objext; then
14010+
pgac_cv_ldap_safe=yes
14011+
else
14012+
$as_echo "$as_me: failed program was:" >&5
14013+
sed 's/^/| /' conftest.$ac_ext >&5
14014+
14015+
pgac_cv_ldap_safe=no
14016+
fi
14017+
14018+
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
14019+
fi
14020+
{ $as_echo "$as_me:$LINENO: result: $pgac_cv_ldap_safe" >&5
14021+
$as_echo "$pgac_cv_ldap_safe" >&6; }
14022+
14023+
if test "$pgac_cv_ldap_safe" != yes; then
14024+
{ $as_echo "$as_me:$LINENO: WARNING:
14025+
*** With OpenLDAP versions 2.4.24 through 2.4.31, inclusive, each backend
14026+
*** process that loads libpq (via WAL receiver, dblink, or postgres_fdw) and
14027+
*** also uses LDAP will crash on exit." >&5
14028+
$as_echo "$as_me: WARNING:
14029+
*** With OpenLDAP versions 2.4.24 through 2.4.31, inclusive, each backend
14030+
*** process that loads libpq (via WAL receiver, dblink, or postgres_fdw) and
14031+
*** also uses LDAP will crash on exit." >&2;}
14032+
fi
1395614033
else
1395714034

1395814035
for ac_header in winldap.h

‎configure.in‎

Lines changed: 29 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1088,10 +1088,39 @@ if test "$with_libxslt" = yes ; then
10881088
AC_CHECK_HEADER(libxslt/xslt.h, [], [AC_MSG_ERROR([header file <libxslt/xslt.h> is required for XSLT support])])
10891089
fi
10901090

1091+
# PGAC_LDAP_SAFE
1092+
# --------------
1093+
# PostgreSQL sometimes loads libldap_r and plain libldap into the same
1094+
# process. Check for OpenLDAP versions known not to tolerate doing so; assume
1095+
# non-OpenLDAP implementations are safe. The dblink test suite exercises the
1096+
# hazardous interaction directly.
1097+
1098+
AC_DEFUN([PGAC_LDAP_SAFE],
1099+
[AC_CACHE_CHECK([for compatible LDAP implementation], [pgac_cv_ldap_safe],
1100+
[AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
1101+
[#include <ldap.h>
1102+
#if !defined(LDAP_VENDOR_VERSION) || \
1103+
(defined(LDAP_API_FEATURE_X_OPENLDAP) && \
1104+
LDAP_VENDOR_VERSION >= 20424 && LDAP_VENDOR_VERSION <= 20431)
1105+
choke me
1106+
#endif], [])],
1107+
[pgac_cv_ldap_safe=yes],
1108+
[pgac_cv_ldap_safe=no])])
1109+
1110+
if test "$pgac_cv_ldap_safe" != yes; then
1111+
AC_MSG_WARN([
1112+
*** With OpenLDAP versions 2.4.24 through 2.4.31, inclusive, each backend
1113+
*** process that loads libpq (via WAL receiver, dblink, or postgres_fdw) and
1114+
*** also uses LDAP will crash on exit.])
1115+
fi])
1116+
1117+
1118+
10911119
if test "$with_ldap" = yes ; then
10921120
if test "$PORTNAME" != "win32"; then
10931121
AC_CHECK_HEADERS(ldap.h, [],
10941122
[AC_MSG_ERROR([header file <ldap.h> is required for LDAP])])
1123+
PGAC_LDAP_SAFE
10951124
else
10961125
AC_CHECK_HEADERS(winldap.h, [],
10971126
[AC_MSG_ERROR([header file <winldap.h> is required for LDAP])],

‎contrib/dblink/Makefile‎

Lines changed: 3 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -9,7 +9,9 @@ SHLIB_PREREQS = submake-libpq
99
EXTENSION = dblink
1010
DATA = dblink--1.0.sql dblink--unpackaged--1.0.sql
1111

12-
REGRESS = dblink
12+
REGRESS = paths dblink
13+
REGRESS_OPTS = --dlpath=$(top_builddir)/src/test/regress
14+
EXTRA_CLEAN = sql/paths.sql expected/paths.out
1315

1416
# the db name is hard-coded in the tests
1517
override USE_MODULE_DB =

‎contrib/dblink/expected/.gitignore‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1 @@
1+
/paths.out

‎contrib/dblink/expected/dblink.out‎

Lines changed: 23 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -105,6 +105,29 @@ SELECT *
105105
FROM dblink('SELECT * FROM foo') AS t(a int, b text, c text[])
106106
WHERE t.a > 7;
107107
ERROR: connection not available
108+
-- The first-level connection's backend will crash on exit given OpenLDAP
109+
-- [2.4.24, 2.4.31]. We won't see evidence of any crash until the victim
110+
-- process terminates and the postmaster responds. If process termination
111+
-- entails writing a core dump, that can take awhile. Wait for the process to
112+
-- vanish. At that point, the postmaster has called waitpid() on the crashed
113+
-- process, and it will accept no new connections until it has reinitialized
114+
-- the cluster. (We can't exploit pg_stat_activity, because the crash happens
115+
-- after the backend updates shared memory to reflect its impending exit.)
116+
DO $pl$
117+
BEGIN
118+
PERFORM wait_pid(crash_pid)
119+
FROM dblink('dbname=contrib_regression', $$
120+
SELECT pg_backend_pid() FROM dblink(
121+
'service=test_ldap dbname=contrib_regression',
122+
-- This string concatenation is a hack to shoehorn a
123+
-- set_pgservicefile call into the SQL statement.
124+
'SELECT 1' || set_pgservicefile('pg_service.conf')
125+
) t(c int)
126+
$$) AS t(crash_pid int);
127+
EXCEPTION WHEN sqlclient_unable_to_establish_sqlconnection THEN
128+
-- Expect "syntax error in service file" in a non-LDAP build.
129+
END
130+
$pl$;
108131
-- create a persistent connection
109132
SELECT dblink_connect('dbname=contrib_regression');
110133
dblink_connect

‎contrib/dblink/input/paths.source‎

Lines changed: 14 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,14 @@
1+
-- Initialization that requires path substitution.
2+
3+
CREATE FUNCTION putenv(text)
4+
RETURNS void
5+
AS '@libdir@/regress@DLSUFFIX@', 'regress_putenv'
6+
LANGUAGE C STRICT;
7+
8+
CREATE FUNCTION wait_pid(int)
9+
RETURNS void
10+
AS '@libdir@/regress@DLSUFFIX@'
11+
LANGUAGE C STRICT;
12+
13+
CREATE FUNCTION set_pgservicefile(text) RETURNS void LANGUAGE SQL
14+
AS $$SELECT putenv('PGSERVICEFILE=@abs_srcdir@/' || $1)$$;

‎contrib/dblink/output/paths.source‎

Lines changed: 11 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,11 @@
1+
-- Initialization that requires path substitution.
2+
CREATE FUNCTION putenv(text)
3+
RETURNS void
4+
AS '@libdir@/regress@DLSUFFIX@', 'regress_putenv'
5+
LANGUAGE C STRICT;
6+
CREATE FUNCTION wait_pid(int)
7+
RETURNS void
8+
AS '@libdir@/regress@DLSUFFIX@'
9+
LANGUAGE C STRICT;
10+
CREATE FUNCTION set_pgservicefile(text) RETURNS void LANGUAGE SQL
11+
AS $$SELECT putenv('PGSERVICEFILE=@abs_srcdir@/' || $1)$$;

‎contrib/dblink/pg_service.conf‎

Lines changed: 7 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,7 @@
1+
# pg_service.conf for minimally exercising libpq use of LDAP.
2+
3+
# Having failed to reach an LDAP server, libpq essentially ignores the
4+
# "service=test_ldap" in its connection string. Contact the "discard"
5+
# service; the test works whether or not it answers.
6+
[test_ldap]
7+
ldap://127.0.0.1:9/base?attribute?one?filter

‎contrib/dblink/sql/.gitignore‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1 @@
1+
/paths.sql

‎contrib/dblink/sql/dblink.sql‎

Lines changed: 24 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -65,6 +65,30 @@ SELECT *
6565
FROM dblink('SELECT * FROM foo') AS t(a int, b text, c text[])
6666
WHERE t.a > 7;
6767

68+
-- The first-level connection's backend will crash on exit given OpenLDAP
69+
-- [2.4.24, 2.4.31]. We won't see evidence of any crash until the victim
70+
-- process terminates and the postmaster responds. If process termination
71+
-- entails writing a core dump, that can take awhile. Wait for the process to
72+
-- vanish. At that point, the postmaster has called waitpid() on the crashed
73+
-- process, and it will accept no new connections until it has reinitialized
74+
-- the cluster. (We can't exploit pg_stat_activity, because the crash happens
75+
-- after the backend updates shared memory to reflect its impending exit.)
76+
DO $pl$
77+
BEGIN
78+
PERFORM wait_pid(crash_pid)
79+
FROM dblink('dbname=contrib_regression', $$
80+
SELECT pg_backend_pid() FROM dblink(
81+
'service=test_ldap dbname=contrib_regression',
82+
-- This string concatenation is a hack to shoehorn a
83+
-- set_pgservicefile call into the SQL statement.
84+
'SELECT 1' || set_pgservicefile('pg_service.conf')
85+
) t(c int)
86+
$$) AS t(crash_pid int);
87+
EXCEPTION WHEN sqlclient_unable_to_establish_sqlconnection THEN
88+
-- Expect "syntax error in service file" in a non-LDAP build.
89+
END
90+
$pl$;
91+
6892
-- create a persistent connection
6993
SELECT dblink_connect('dbname=contrib_regression');
7094

0 commit comments

Comments
 (0)