Some detection whether we need to use -lldap_r to get threadsafe libldap

mistotebe · mistotebe · commit 77e0b19204a8 · 2022-01-27T10:36:39.000Z
Closes #432
diff --git a/setup.cfg b/setup.cfg
@@ -21,9 +21,11 @@ defines = HAVE_SASL HAVE_TLS HAVE_LIBLDAP_R
 extra_compile_args =
 extra_objects =
 
+# Uncomment this if auto-detection doesn't work for you (e.g. loading
+# libldap needs to take 'library_dirs' into account)
 # Example for full-featured build:
 # Support for StartTLS/LDAPS, SASL bind and reentrant libldap_r.
-libs = ldap_r lber
+#libs = ldap_r lber
 
 # Installation options
 [install]
@@ -33,7 +35,7 @@ optimize = 1
 # Linux distributors/packagers should adjust these settings
 [bdist_rpm]
 provides = python-ldap
-requires = python libldap-2_4
+requires = python libldap-2
 vendor = python-ldap project
 packager = python-ldap team
 distribution_name = openSUSE 11.x
diff --git a/setup.py b/setup.py
@@ -24,7 +24,7 @@ class OpenLDAP2:
   extra_compile_args = []
   extra_link_args = []
   extra_objects = []
-  libs = ['ldap', 'lber']
+  libs = None
   defines = []
   extra_files = []
 
@@ -38,6 +38,49 @@ class OpenLDAP2:
     if cfg.has_option('_ldap', name):
       setattr(LDAP_CLASS, name, cfg.get('_ldap', name).split())
 
+if LDAP_CLASS.libs is None:
+  # libldap(_r) not selected by setup.cfg, turn to auto-detection
+  from ctypes import cdll, c_void_p, c_char_p, c_int, byref, Structure
+  import ctypes.util
+
+  NULL = c_void_p()
+  LDAP_OPT_API_FEATURE_INFO = 0x15
+  class ldap_apifeature_info(Structure):
+    _fields_ = [
+        ("ldapaif_info_version", c_int),
+        ("ldapaif_name", c_char_p),
+        ("ldapaif_version", c_int)
+    ]
+
+  for name in ('ldap', 'ldap_r'):
+    ldapname = ctypes.util.find_library(name)
+    if not ldapname:
+      continue
+
+    try:
+      libldap = cdll.LoadLibrary(ldapname)
+    except OSError:
+      # Cannot load this version of libldap
+      continue
+
+    info = ldap_apifeature_info(1, b"X_OPENLDAP_THREAD_SAFE")
+
+    if libldap.ldap_get_option(NULL, LDAP_OPT_API_FEATURE_INFO, byref(info)):
+      # Does not support THREADSAFE
+      continue
+
+    if info.ldapaif_version != 1:
+      # Does not support THREADSAFE
+      continue
+
+    LDAP_CLASS.libs = [name, 'lber']
+    if 'HAVE_LIBLDAP_R' not in LDAP_CLASS.defines:
+      LDAP_CLASS.defines.append('HAVE_LIBLDAP_R')
+    break
+  else:
+    # At least try
+    LDAP_CLASS.libs = ['ldap', 'lber']
+
 for i in range(len(LDAP_CLASS.defines)):
   LDAP_CLASS.defines[i]=((LDAP_CLASS.defines[i],None))
 
@@ -132,7 +175,6 @@ class OpenLDAP2:
       extra_objects = LDAP_CLASS.extra_objects,
       runtime_library_dirs = (not sys.platform.startswith("win"))*LDAP_CLASS.library_dirs,
       define_macros = LDAP_CLASS.defines + \
-        ('ldap_r' in LDAP_CLASS.libs or 'oldap_r' in LDAP_CLASS.libs)*[('HAVE_LIBLDAP_R',None)] + \
         ('sasl' in LDAP_CLASS.libs or 'sasl2' in LDAP_CLASS.libs or 'libsasl' in LDAP_CLASS.libs)*[('HAVE_SASL',None)] + \
         ('ssl' in LDAP_CLASS.libs and 'crypto' in LDAP_CLASS.libs)*[('HAVE_TLS',None)] + \
         [
