Replace loading of ldap_start_tls_sA() by direct function call

michaelpq · michaelpq · commit c3fb5809eae3 · 2022-09-12T09:07:10.000+09:00
This change impacts the backend-side code in charge of starting a LDAP TLS session. It is a bit sad that it is not possible to unify the WIN32 and non-WIN32 code paths, but the different number of arguments for both discard this possibility. This is similar to 47bd0b3, where this replaces the last function loading that seems worth it, any others being either environment or version-dependent. Reported-by: Thomas Munro Reviewed-by: Thomas Munro Discussion: https://postgr.es/m/Yx0rxpNgDh8tN4XA@paquier.xyz
diff --git a/src/backend/libpq/auth.c b/src/backend/libpq/auth.c
@@ -135,14 +135,6 @@ static int	CheckBSDAuth(Port *port, char *user);
 #else
 #include <winldap.h>
 
-/* Correct header from the Platform SDK */
-typedef
-ULONG		(*__ldap_start_tls_sA) (IN PLDAP ExternalHandle,
-									OUT PULONG ServerReturnValue,
-									OUT LDAPMessage **result,
-									IN PLDAPControlA * ServerControls,
-									IN PLDAPControlA * ClientControls
-);
 #endif
 
 static int	CheckLDAPAuth(Port *port);
@@ -2348,48 +2340,7 @@ InitializeLDAPConnection(Port *port, LDAP **ldap)
 #ifndef WIN32
 		if ((r = ldap_start_tls_s(*ldap, NULL, NULL)) != LDAP_SUCCESS)
 #else
-		static __ldap_start_tls_sA _ldap_start_tls_sA = NULL;
-
-		if (_ldap_start_tls_sA == NULL)
-		{
-			/*
-			 * Need to load this function dynamically because it may not exist
-			 * on Windows, and causes a load error for the whole exe if
-			 * referenced.
-			 */
-			HANDLE		ldaphandle;
-
-			ldaphandle = LoadLibrary("WLDAP32.DLL");
-			if (ldaphandle == NULL)
-			{
-				/*
-				 * should never happen since we import other files from
-				 * wldap32, but check anyway
-				 */
-				ereport(LOG,
-						(errmsg("could not load library \"%s\": error code %lu",
-								"WLDAP32.DLL", GetLastError())));
-				ldap_unbind(*ldap);
-				return STATUS_ERROR;
-			}
-			_ldap_start_tls_sA = (__ldap_start_tls_sA) (pg_funcptr_t) GetProcAddress(ldaphandle, "ldap_start_tls_sA");
-			if (_ldap_start_tls_sA == NULL)
-			{
-				ereport(LOG,
-						(errmsg("could not load function _ldap_start_tls_sA in wldap32.dll"),
-						 errdetail("LDAP over SSL is not supported on this platform.")));
-				ldap_unbind(*ldap);
-				FreeLibrary(ldaphandle);
-				return STATUS_ERROR;
-			}
-
-			/*
-			 * Leak LDAP handle on purpose, because we need the library to
-			 * stay open. This is ok because it will only ever be leaked once
-			 * per process and is automatically cleaned up on process exit.
-			 */
-		}
-		if ((r = _ldap_start_tls_sA(*ldap, NULL, NULL, NULL, NULL)) != LDAP_SUCCESS)
+		if ((r = ldap_start_tls_s(*ldap, NULL, NULL, NULL, NULL)) != LDAP_SUCCESS)
 #endif
 		{
 			ereport(LOG,
