Make tls_init() concurrently callable using pthread_once().

ok jsing@

This brings pthread_once usage into libressl, which will
need to get dealt with correctly in portable.

This sets us up to autoinit libtls, and we will also be
using pthread_once to deal with autoinit stuff in libssl
and libcrypto

2 files changed, 23 insertions, 15 deletions

diff --git a/lib/libtls/man/tls_init.3 b/lib/libtls/man/tls_init.3
index c83c0375abe..fe8847d0acd 100644
--- a/lib/libtls/man/tls_init.3
+++ b/lib/libtls/man/tls_init.3
@@ -1,4 +1,4 @@
-.\" $OpenBSD: tls_init.3,v 1.7 2017/05/06 21:18:48 jsing Exp $
+.\" $OpenBSD: tls_init.3,v 1.8 2018/03/07 17:17:47 beck Exp $
 .\"
 .\" Copyright (c) 2014 Ted Unangst <tedu@openbsd.org>
 .\" Copyright (c) 2016 Joel Sing <jsing@openbsd.org>
@@ -16,7 +16,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: May 6 2017 $
+.Dd $Mdocdate: March 7 2018 $
 .Dt TLS_INIT 3
 .Os
 .Sh NAME
@@ -46,7 +46,7 @@ The
 .Fn tls_init
 function initializes global data structures.
 It should be called once before any other functions.
-It may be called more than once, but not concurrently.
+It may be called more than once, and may be called concurrently.
 .Pp
 Before a connection is created, a configuration must be created.
 The
diff --git a/lib/libtls/tls.c b/lib/libtls/tls.c
index 8f2c7dde057..4a9db289bd6 100644
--- a/lib/libtls/tls.c
+++ b/lib/libtls/tls.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls.c,v 1.75 2018/02/10 04:57:35 jsing Exp $ */
+/* $OpenBSD: tls.c,v 1.76 2018/03/07 17:17:47 beck Exp $ */
 /*
  * Copyright (c) 2014 Joel Sing <jsing@openbsd.org>
  *
@@ -19,6 +19,7 @@
 
 #include <errno.h>
 #include <limits.h>
+#include <pthread.h>
 #include <stdlib.h>
 #include <unistd.h>
 
@@ -35,28 +36,35 @@
 
 static struct tls_config *tls_config_default;
 
-int
-tls_init(void)
-{
-	static int tls_initialised = 0;
-
-	if (tls_initialised)
-		return (0);
+static int tls_init_rv = -1;
 
+static void
+tls_do_init(void)
+{
 	SSL_load_error_strings();
 	SSL_library_init();
 
 	if (BIO_sock_init() != 1)
-		return (-1);
+		return;
 
 	if ((tls_config_default = tls_config_new()) == NULL)
-		return (-1);
+		return;
 
 	tls_config_default->refcount++;
 
-	tls_initialised = 1;
+	tls_init_rv = 0;
+	return;
+}
 
-	return (0);
+int
+tls_init(void)
+{
+	static pthread_once_t once = PTHREAD_ONCE_INIT;
+
+	if (pthread_once(&once, tls_do_init) != 0)
+		return -1;
+
+	return tls_init_rv;
 }
 
 const char *