priorities: share priority structures across sessions

As the contents of the priority cache grows, it makes sense to shared
these structures across many sessions (in server side) rather than
copying them to a session. All overrides of the priority contents
were moved to session->internals. On client side where gnutls_priority_set_direct()
is more commonly used, ensure that the set priority is deinitialized.

That also introduces gnutls_priority_set2() which does not copy the priority
contents by default.

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

1 files changed, 63 insertions, 10 deletions

diff --git a/lib/priority.c b/lib/priority.c
index a41944c9c7..8fca2f194c 100644
--- a/lib/priority.c
+++ b/lib/priority.c
@@ -533,25 +533,64 @@ 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;
 	}
 
-	memcpy(&session->internals.priorities, priority,
-	       sizeof(struct gnutls_priority_st));
+	if (session->internals.deinit_priorities &&
+	    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;
+	}
 
 	/* set the current version to the first in the chain.
 	 * This will be overridden later.
 	 */
-	if (session->internals.priorities.protocol.algorithms > 0) {
+	if (session->internals.priorities->protocol.algorithms > 0) {
 		if (_gnutls_set_current_version(session,
-					    session->internals.priorities.
+					    session->internals.priorities->
 					    protocol.priority[0]) < 0) {
 			return gnutls_assert_val(GNUTLS_E_UNSUPPORTED_VERSION_PACKET);
 		}
@@ -562,12 +601,23 @@ gnutls_priority_set(gnutls_session_t session, gnutls_priority_t priority)
 		_gnutls_ext_unset_session_data(session, GNUTLS_EXTENSION_SESSION_TICKET);
 	}
 
-	if (session->internals.priorities.protocol.algorithms == 0 ||
-	    session->internals.priorities.cs.size == 0)
+	if (session->internals.priorities->protocol.algorithms == 0 ||
+	    session->internals.priorities->cs.size == 0)
 		return gnutls_assert_val(GNUTLS_E_NO_PRIORITIES_WERE_SET);
 
 	ADD_PROFILE_VFLAGS(session, priority->additional_verify_flags);
 
+	/* mirror variables */
+#undef COPY_TO_INTERNALS
+#define COPY_TO_INTERNALS(xx) session->internals.xx = priority->_##xx
+	COPY_TO_INTERNALS(allow_large_records);
+	COPY_TO_INTERNALS(no_etm);
+	COPY_TO_INTERNALS(no_ext_master_secret);
+	COPY_TO_INTERNALS(allow_key_usage_violation);
+	COPY_TO_INTERNALS(allow_wrong_pms);
+	COPY_TO_INTERNALS(dumbfw);
+	COPY_TO_INTERNALS(dh_prime_bits);
+
 	return 0;
 }
 
@@ -744,7 +794,7 @@ int check_level(const char *level, gnutls_priority_t priority_cache,
 
 static void enable_compat(gnutls_priority_t c)
 {
-	ENABLE_COMPAT(c);
+	ENABLE_PRIO_COMPAT(c);
 }
 static void enable_server_key_usage_violations(gnutls_priority_t c)
 {
@@ -752,7 +802,7 @@ static void enable_server_key_usage_violations(gnutls_priority_t c)
 }
 static void enable_dumbfw(gnutls_priority_t c)
 {
-	c->dumbfw = 1;
+	c->_dumbfw = 1;
 }
 static void enable_no_extensions(gnutls_priority_t c)
 {
@@ -760,11 +810,11 @@ static void enable_no_extensions(gnutls_priority_t c)
 }
 static void enable_no_ext_master_secret(gnutls_priority_t c)
 {
-	c->no_ext_master_secret = 1;
+	c->_no_ext_master_secret = 1;
 }
 static void enable_no_etm(gnutls_priority_t c)
 {
-	c->no_etm = 1;
+	c->_no_etm = 1;
 }
 static void enable_no_tickets(gnutls_priority_t c)
 {
@@ -1501,6 +1551,9 @@ gnutls_priority_set_direct(gnutls_session_t session,
 		return ret;
 	}
 
+	/* ensure this priority is deinitialized with the session */
+	session->internals.deinit_priorities = 1;
+
 	gnutls_priority_deinit(prio);
 
 	return 0;