gnutls_priority_set: use reference counting

That eliminates the need for gnutls_priority_set2() which is now
removed.

Signed-off-by: Nikos Mavrogiannopoulos <nmav@redhat.com>

5 files changed, 29 insertions, 55 deletions

diff --git a/lib/gnutls_int.h b/lib/gnutls_int.h
index aad07979d6..d624a05284 100644
--- a/lib/gnutls_int.h
+++ b/lib/gnutls_int.h
@@ -666,6 +666,8 @@ typedef struct sign_algo_list_st {
 	unsigned int size;
 } sign_algo_list_st;
 
+#include "atomic.h"
+
 /* For the external api */
 struct gnutls_priority_st {
 	priority_st protocol;
@@ -717,6 +719,7 @@ struct gnutls_priority_st {
 	bool _dumbfw;
 	unsigned int _dh_prime_bits;	/* old (deprecated) variable */
 
+	DEF_ATOMIC_INT(usage_cnt);
 };
 
 /* Allow around 50KB of length-hiding padding
@@ -837,9 +840,6 @@ typedef struct {
 
 	/* priorities */
 	struct gnutls_priority_st *priorities;
-	/* non-zero if the priorities are assigned only to this session (and
-	 * thus should be freed by it */
-	bool deinit_priorities;
 
 	/* variables directly set when setting the priorities above, or
 	 * when overriding them */
diff --git a/lib/includes/gnutls/gnutls.h.in b/lib/includes/gnutls/gnutls.h.in
index 6c1012f175..35b2de3e91 100644
--- a/lib/includes/gnutls/gnutls.h.in
+++ b/lib/includes/gnutls/gnutls.h.in
@@ -1370,10 +1370,6 @@ gnutls_priority_string_list(unsigned iter, unsigned int flags);
 int gnutls_priority_set(gnutls_session_t session,
 			gnutls_priority_t priority);
 
-#define GNUTLS_PRIORITY_FLAG_COPY 1
-int gnutls_priority_set2(gnutls_session_t session,
-			 gnutls_priority_t priority,
-			 unsigned int flags);
 int gnutls_priority_set_direct(gnutls_session_t session,
 			       const char *priorities,
 			       const char **err_pos);
diff --git a/lib/libgnutls.map b/lib/libgnutls.map
index 8121f40773..2a9d0af70a 100644
--- a/lib/libgnutls.map
+++ b/lib/libgnutls.map
@@ -1164,7 +1164,6 @@ GNUTLS_3_4
 	gnutls_sign_supports_pk_algorithm;
 	gnutls_privkey_sign_hash2;
 	gnutls_privkey_sign_data2;
-	gnutls_priority_set2;
 	gnutls_sign_is_secure2;
  local:
 	*;
diff --git a/lib/priority.c b/lib/priority.c
index 730edd1131..7a17964bad 100644
--- a/lib/priority.c
+++ b/lib/priority.c
@@ -537,57 +537,21 @@ static void prio_add(priority_st * priority_list, unsigned int algo)
  * Sets the priorities to use on the ciphers, key exchange methods,
  * and macs.
  *
- * This is identical to calling gnutls_priority_set2() with
- * %GNUTLS_PRIORITY_FLAG_COPY.
- *
  * Returns: %GNUTLS_E_SUCCESS on success, or an error code.
  **/
 int
 gnutls_priority_set(gnutls_session_t session, gnutls_priority_t priority)
 {
-	return gnutls_priority_set2(session, priority, GNUTLS_PRIORITY_FLAG_COPY);
-}
-
-/**
- * gnutls_priority_set2:
- * @session: is a #gnutls_session_t type.
- * @priority: is a #gnutls_priority_t type.
- * @flags: zero or %GNUTLS_PRIORITY_FLAG_COPY
- *
- * Sets the priorities to use on the ciphers, key exchange methods,
- * and macs.
- *
- * Unless %GNUTLS_PRIORITY_FLAG_COPY is specified, the @priority reference
- * must remain valid for the lifetime of the session.
- *
- * Returns: %GNUTLS_E_SUCCESS on success, or an error code.
- **/
-int
-gnutls_priority_set2(gnutls_session_t session, gnutls_priority_t priority, unsigned int flags)
-{
 	if (priority == NULL) {
 		gnutls_assert();
 		return GNUTLS_E_NO_CIPHER_SUITES;
 	}
 
-	if (session->internals.deinit_priorities &&
-	    session->internals.priorities)
+	if (session->internals.priorities)
 		gnutls_priority_deinit(session->internals.priorities);
 
-	if (flags & GNUTLS_PRIORITY_FLAG_COPY) {
-		session->internals.priorities = gnutls_malloc(sizeof(*session->internals.priorities));
-		if (session->internals.priorities == NULL)
-			return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
-
-		/* it is fine to use memcpy() here since we are only storing
-		 * values and pointers to constant static data. */
-		memcpy(session->internals.priorities, priority, sizeof(*priority));
-
-		session->internals.deinit_priorities = 1;
-	} else {
-		session->internals.priorities = priority;
-		session->internals.deinit_priorities = 0;
-	}
+	session->internals.priorities = priority;
+	gnutls_atomic_increment(&priority->usage_cnt);
 
 	/* set the current version to the first in the chain.
 	 * This will be overridden later.
@@ -1318,6 +1282,7 @@ gnutls_priority_init(gnutls_priority_t * priority_cache,
 	 */
 	(*priority_cache)->sr = SR_PARTIAL;
 	(*priority_cache)->min_record_version = 1;
+	gnutls_atomic_init(&(*priority_cache)->usage_cnt);
 
 	if (priorities == NULL)
 		priorities = DEFAULT_PRIORITY_STRING;
@@ -1500,7 +1465,7 @@ gnutls_priority_init(gnutls_priority_t * priority_cache,
 		}
 	}
 	free(darg);
-	gnutls_free(*priority_cache);
+	gnutls_priority_deinit(*priority_cache);
 	*priority_cache = NULL;
 
 	return GNUTLS_E_INVALID_REQUEST;
@@ -1515,7 +1480,24 @@ gnutls_priority_init(gnutls_priority_t * priority_cache,
  **/
 void gnutls_priority_deinit(gnutls_priority_t priority_cache)
 {
-	gnutls_free(priority_cache);
+	if (priority_cache == NULL)
+		return;
+
+	/* Note that here we care about the following two cases:
+	 * 1. Multiple sessions or different threads holding a reference + a global reference
+	 * 2. One session holding a reference with a possible global reference
+	 *
+	 * As such, it will never be that two threads reach the
+	 * zero state at the same time, unless the global reference
+	 * is cleared too, which is invalid state.
+	 */
+	if (gnutls_atomic_val(&priority_cache->usage_cnt) == 0) {
+		gnutls_atomic_deinit(&priority_cache->usage_cnt);
+		gnutls_free(priority_cache);
+		return;
+	} else {
+		gnutls_atomic_decrement(&priority_cache->usage_cnt);
+	}
 }
 
 
@@ -1555,9 +1537,7 @@ gnutls_priority_set_direct(gnutls_session_t session,
 		return ret;
 	}
 
-	/* ensure this priority is deinitialized with the session */
-	session->internals.deinit_priorities = 1;
-
+	/* ensure that the session holds the only reference for the struct */
 	gnutls_priority_deinit(prio);
 
 	return 0;
diff --git a/lib/state.c b/lib/state.c
index d3e75c71c2..a36ed92d25 100644
--- a/lib/state.c
+++ b/lib/state.c
@@ -429,9 +429,8 @@ void gnutls_deinit(gnutls_session_t session)
 	gnutls_credentials_clear(session);
 	_gnutls_selected_certs_deinit(session);
 
-	if (session->internals.deinit_priorities &&
-	    session->internals.priorities)
-		gnutls_priority_deinit(session->internals.priorities);
+	/* we rely on priorities' internal reference counting */
+	gnutls_priority_deinit(session->internals.priorities);
 
 	gnutls_free(session);
 }