Remove the thread-safety flag from the kdb plugin interface. Instead,

have the kdb code assume the plugin is thread safe, and implement some
quick and dirty wrapper functions in the db2 plugin to make it use a
local mutex.

There's still some mutex code in the kdb library that should be
reviewed, and simplified or removed.

ticket: 3416
status: open

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@17611 dc483132-0cff-0310-8789-dd5450dbe970

4 files changed, 202 insertions, 31 deletions

diff --git a/src/plugins/kdb/db2/ChangeLog b/src/plugins/kdb/db2/ChangeLog
index e88e25d732..c6461f9ad8 100644
--- a/src/plugins/kdb/db2/ChangeLog
+++ b/src/plugins/kdb/db2/ChangeLog
@@ -1,3 +1,17 @@
+2006-01-25  Ken Raeburn  <raeburn@mit.edu>
+
+	* Makefile.in (DEFINES): New variable; define macro PLUGIN.
+	* db2_exp.c (krb5_db2_mutex): New variable.
+	(wrap_*): Lots of new functions; lock the mutex, call the real
+	function, unlock the mutex.
+	(WRAP, WRAP_K, WRAP_VOID): Quick and dirty macros for implementing
+	the above.
+	(hack_init, hack_cleanup): New functions.  Call the regular init
+	or cleanup function, but also deal with the new mutex.
+	(krb5_db_vftabl_db2): Use the hack/wrap functions.
+
+	* kdb_db2.h (krb5_db2_get_policy): Delete duplicate declaration.
+
 2005-12-16  Ken Raeburn  <raeburn@mit.edu>
 
 	* Makefile.in (myfulldir, RELDIR): Updated for directory rename.
diff --git a/src/plugins/kdb/db2/Makefile.in b/src/plugins/kdb/db2/Makefile.in
index 6935bd4679..06b037ce0e 100644
--- a/src/plugins/kdb/db2/Makefile.in
+++ b/src/plugins/kdb/db2/Makefile.in
@@ -8,6 +8,7 @@ PROG_LIBPATH=-L$(TOPLIBD)
 PROG_RPATH=$(KRB5_LIBDIR)
 
 LOCALINCLUDES = -I../../../lib/kdb -I$(srcdir)/../../../lib/kdb
+DEFINES = -DPLUGIN
 
 DB_VERSION	= @DB_VERSION@
 DB_DEPS		= $(DB_DEPS-@DB_HEADER_VERSION@)
diff --git a/src/plugins/kdb/db2/db2_exp.c b/src/plugins/kdb/db2/db2_exp.c
index f119de3de9..29eae05669 100644
--- a/src/plugins/kdb/db2/db2_exp.c
+++ b/src/plugins/kdb/db2/db2_exp.c
@@ -25,6 +25,168 @@ static char *_csrc = "@(#) %filespec: db2_exp.c~5 %  (%full_filespec: db2_exp.c~
 #include "kdb_xdr.h"
 #include "policy_db.h"
 
+/* Quick and dirty wrapper functions to provide for thread safety
+   within the plugin, instead of making the kdb5 library do it.  Eventually
+   these should be integrated into the real functions.
+
+   Some of the functions wrapped here are also called directly from
+   within this library (e.g., create calls open), so simply dropping
+   locking code into the top and bottom of each referenced function
+   won't do.  (We aren't doing recursive locks, currently.)  */
+
+static k5_mutex_t *krb5_db2_mutex;
+
+#define WRAP(NAME,TYPE,ARGLIST,ARGNAMES,ERROR_RESULT)	\
+	static TYPE wrap_##NAME ARGLIST			\
+	{						\
+	    TYPE result;				\
+	    int code = k5_mutex_lock (krb5_db2_mutex);	\
+	    if (code) { return ERROR_RESULT; }		\
+	    result = NAME ARGNAMES;			\
+	    k5_mutex_unlock (krb5_db2_mutex);		\
+	    return result;				\
+	}						\
+	/* hack: decl to allow a following ";" */	\
+	static TYPE wrap_##NAME ()
+
+/* Two special cases: void (can't assign result), and krb5_error_code
+   (return error from locking code).  */
+
+#define WRAP_VOID(NAME,ARGLIST,ARGNAMES)		\
+	static void wrap_##NAME ARGLIST			\
+	{						\
+	    int code = k5_mutex_lock (krb5_db2_mutex);	\
+	    if (code) { return; }			\
+	    NAME ARGNAMES;				\
+	    k5_mutex_unlock (krb5_db2_mutex);		\
+	}						\
+	/* hack: decl to allow a following ";" */	\
+	static void wrap_##NAME ()
+
+#define WRAP_K(NAME,ARGLIST,ARGNAMES)			\
+	WRAP(NAME,krb5_error_code,ARGLIST,ARGNAMES,code)
+
+WRAP_K (krb5_db2_open,
+	( krb5_context kcontext,
+	  char *conf_section,
+	  char **db_args,
+	  int mode ),
+	(kcontext, conf_section, db_args, mode));
+WRAP_K (krb5_db2_db_fini, (krb5_context ctx), (ctx));
+WRAP_K (krb5_db2_create,
+	( krb5_context kcontext, char *conf_section, char **db_args ),
+	(kcontext, conf_section, db_args));
+WRAP_K (krb5_db2_destroy,
+	( krb5_context kcontext, char *conf_section, char **db_args ),
+	(kcontext, conf_section, db_args));
+WRAP_K (krb5_db2_db_get_age,
+	(krb5_context ctx,
+		   char *s,
+	 time_t *t),
+	(ctx, s, t));
+WRAP_K (krb5_db2_db_set_option,
+	( krb5_context kcontext, 
+	  int option, 
+	  void *value ),
+	(kcontext, option, value));
+
+WRAP_K (krb5_db2_db_lock,
+	( krb5_context 	  context,
+	  int 	 	  in_mode),
+	(context, in_mode));
+WRAP_K (krb5_db2_db_unlock, (krb5_context ctx), (ctx));
+
+WRAP_K (krb5_db2_db_get_principal,
+	(krb5_context ctx,
+		   krb5_const_principal p,
+		   krb5_db_entry *d,
+		   int * i,
+	 krb5_boolean *b),
+	(ctx, p, d, i, b));
+WRAP_K (krb5_db2_db_free_principal,
+	(krb5_context ctx,
+		   krb5_db_entry *d,
+	 int i),
+	(ctx, d, i));
+WRAP_K (krb5_db2_db_put_principal,
+	(krb5_context ctx,
+	 krb5_db_entry *d,
+	 int *i,
+	 char **db_args),
+	(ctx, d, i, db_args));
+WRAP_K (krb5_db2_db_delete_principal,
+	(krb5_context context,
+	 krb5_const_principal searchfor,
+	 int *nentries),
+	(context, searchfor, nentries));
+
+WRAP_K (krb5_db2_db_iterate,
+	(krb5_context ctx, char *s,
+	 krb5_error_code (*f) (krb5_pointer,
+			      krb5_db_entry *),
+	 krb5_pointer p),
+	(ctx, s, f, p));
+
+WRAP_K (krb5_db2_create_policy,
+	(krb5_context context, osa_policy_ent_t entry),
+	(context, entry));
+WRAP_K (krb5_db2_get_policy,
+	( krb5_context kcontext,
+	  char *name,
+	  osa_policy_ent_t *policy,
+	  int *cnt),
+	(kcontext, name, policy, cnt));
+WRAP_K (krb5_db2_put_policy,
+	( krb5_context kcontext, osa_policy_ent_t policy ),
+	(kcontext, policy));
+WRAP_K (krb5_db2_iter_policy,
+	( krb5_context kcontext,
+	  char *match_entry,
+	  osa_adb_iter_policy_func func,
+	  void *data ),
+	(kcontext, match_entry, func, data));
+WRAP_K (krb5_db2_delete_policy,
+	( krb5_context kcontext, char *policy ),
+	(kcontext, policy));
+WRAP_VOID (krb5_db2_free_policy,
+	   ( krb5_context kcontext, osa_policy_ent_t entry ),
+	   (kcontext, entry));
+
+WRAP (krb5_db2_alloc, void *,
+      ( krb5_context kcontext,  
+	void *ptr, 
+	size_t size ),
+      (kcontext, ptr, size), NULL);
+WRAP_VOID (krb5_db2_free,
+	   ( krb5_context kcontext, void *ptr ),
+	   (kcontext, ptr));
+
+WRAP_K (krb5_db2_set_master_key_ext,
+	( krb5_context kcontext, char *pwd, krb5_keyblock *key),
+	(kcontext, pwd, key));
+WRAP_K (krb5_db2_db_get_mkey,
+	( krb5_context context, krb5_keyblock **key),
+	(context, key));
+
+static krb5_error_code
+hack_init (krb5_set_err_func_t f)
+{
+    krb5_error_code c;
+    c = krb5int_mutex_alloc (&krb5_db2_mutex);
+    if (c)
+	return c;
+    return krb5_db2_lib_init (f);
+}
+
+static krb5_error_code
+hack_cleanup (void)
+{
+    krb5int_mutex_free (krb5_db2_mutex);
+    krb5_db2_mutex = NULL;
+    return krb5_db2_lib_cleanup();
+}
+
+
 /*
  *      Exposed API
  */
@@ -32,33 +194,32 @@ static char *_csrc = "@(#) %filespec: db2_exp.c~5 %  (%full_filespec: db2_exp.c~
 kdb_vftabl krb5_db_vftabl_db2 = {
   1,                                      /* major version number 1 */
   0,                                      /* minor version number 0 */
-  0,                                      /* TBD. Not sure whether thread safe. For now, its not */
-  /* init_library */			       krb5_db2_lib_init,
-  /* fini_library */			       krb5_db2_lib_cleanup,
-  /* init_module */			       krb5_db2_open,
-  /* fini_module */			       krb5_db2_db_fini,
-  /* db_create */			       krb5_db2_create,
-  /* db_destroy */			       krb5_db2_destroy,
-  /* db_get_age */                             krb5_db2_db_get_age,
-  /* db_set_option */			       krb5_db2_db_set_option,
-  /* db_lock */				       krb5_db2_db_lock,
-  /* db_unlock */			       krb5_db2_db_unlock,
-  /* db_get_principal */		       krb5_db2_db_get_principal,
-  /* db_free_principal */		       krb5_db2_db_free_principal,
-  /* db_put_principal */		       krb5_db2_db_put_principal,
-  /* db_delete_principal */		       krb5_db2_db_delete_principal,
-  /* db_iterate */			       krb5_db2_db_iterate,
-  /* db_create_policy */                       krb5_db2_create_policy,
-  /* db_get_policy */                          krb5_db2_get_policy,
-  /* db_put_policy */                          krb5_db2_put_policy,
-  /* db_iter_policy */                         krb5_db2_iter_policy,
-  /* db_delete_policy */                       krb5_db2_delete_policy,
-  /* db_free_policy */                         krb5_db2_free_policy,
+  /* init_library */			       hack_init,
+  /* fini_library */			       hack_cleanup,
+  /* init_module */			       wrap_krb5_db2_open,
+  /* fini_module */			       wrap_krb5_db2_db_fini,
+  /* db_create */			       wrap_krb5_db2_create,
+  /* db_destroy */			       wrap_krb5_db2_destroy,
+  /* db_get_age */                             wrap_krb5_db2_db_get_age,
+  /* db_set_option */			       wrap_krb5_db2_db_set_option,
+  /* db_lock */				       wrap_krb5_db2_db_lock,
+  /* db_unlock */			       wrap_krb5_db2_db_unlock,
+  /* db_get_principal */		       wrap_krb5_db2_db_get_principal,
+  /* db_free_principal */		       wrap_krb5_db2_db_free_principal,
+  /* db_put_principal */		       wrap_krb5_db2_db_put_principal,
+  /* db_delete_principal */		       wrap_krb5_db2_db_delete_principal,
+  /* db_iterate */			       wrap_krb5_db2_db_iterate,
+  /* db_create_policy */                       wrap_krb5_db2_create_policy,
+  /* db_get_policy */                          wrap_krb5_db2_get_policy,
+  /* db_put_policy */                          wrap_krb5_db2_put_policy,
+  /* db_iter_policy */                         wrap_krb5_db2_iter_policy,
+  /* db_delete_policy */                       wrap_krb5_db2_delete_policy,
+  /* db_free_policy */                         wrap_krb5_db2_free_policy,
   /* db_supported_realms */		       NULL,
   /* db_free_supported_realms */	       NULL,
   /* errcode_2_string */                       NULL,
-  /* db_alloc */                               krb5_db2_alloc,
-  /* db_free */                                krb5_db2_free,
-  /* set_master_key */			       krb5_db2_set_master_key_ext,
-  /* get_master_key */			       krb5_db2_db_get_mkey
+  /* db_alloc */                               wrap_krb5_db2_alloc,
+  /* db_free */                                wrap_krb5_db2_free,
+  /* set_master_key */			       wrap_krb5_db2_set_master_key_ext,
+  /* get_master_key */			       wrap_krb5_db2_db_get_mkey
 };
diff --git a/src/plugins/kdb/db2/kdb_db2.h b/src/plugins/kdb/db2/kdb_db2.h
index ba03ea36f3..77ca60c334 100644
--- a/src/plugins/kdb/db2/kdb_db2.h
+++ b/src/plugins/kdb/db2/kdb_db2.h
@@ -190,11 +190,6 @@ krb5_error_code krb5_db2_get_policy ( krb5_context kcontext,
 				      osa_policy_ent_t *policy,
 				      int *cnt);
 
-krb5_error_code krb5_db2_get_policy ( krb5_context kcontext,
-				      char *name,
-				      osa_policy_ent_t *policy,
-				      int *cnt);
-
 krb5_error_code krb5_db2_put_policy ( krb5_context kcontext,
 				      osa_policy_ent_t policy );