Add RUN_ONCE support to zlib init

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/14940)

1 files changed, 45 insertions, 46 deletions

diff --git a/crypto/comp/c_zlib.c b/crypto/comp/c_zlib.c
index 4d81b5f53e..a27bbeacb1 100644
--- a/crypto/comp/c_zlib.c
+++ b/crypto/comp/c_zlib.c
@@ -15,6 +15,7 @@
 #include <openssl/err.h>
 #include "crypto/cryptlib.h"
 #include "internal/bio.h"
+#include "internal/thread_once.h"
 #include "comp_local.h"
 
 COMP_METHOD *COMP_zlib(void);
@@ -102,7 +103,6 @@ static deflate_ft p_deflate = NULL;
 static deflateInit__ft p_deflateInit_ = NULL;
 static zError__ft p_zError = NULL;
 
-static int zlib_loaded = 0;     /* only attempt to init func pts once */
 static DSO *zlib_dso = NULL;
 
 #  define compress                p_compress
@@ -204,61 +204,58 @@ static int zlib_stateful_expand_block(COMP_CTX *ctx, unsigned char *out,
     return olen - state->istream.avail_out;
 }
 
-#endif
-
-COMP_METHOD *COMP_zlib(void)
+static CRYPTO_ONCE zlib_once = CRYPTO_ONCE_STATIC_INIT;
+DEFINE_RUN_ONCE_STATIC(ossl_comp_zlib_init)
 {
-    COMP_METHOD *meth = &zlib_method_nozlib;
-
-#ifdef ZLIB_SHARED
+# ifdef ZLIB_SHARED
     /* LIBZ may be externally defined, and we should respect that value */
-# ifndef LIBZ
-#  if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
-#   define LIBZ "ZLIB1"
-#  elif defined(OPENSSL_SYS_VMS)
-#   define LIBZ "LIBZ"
-#  else
-#   define LIBZ "z"
+#  ifndef LIBZ
+#   if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
+#    define LIBZ "ZLIB1"
+#   elif defined(OPENSSL_SYS_VMS)
+#    define LIBZ "LIBZ"
+#   else
+#    define LIBZ "z"
+#   endif
 #  endif
-# endif
 
-    if (!zlib_loaded) {
-        zlib_dso = DSO_load(NULL, LIBZ, NULL, 0);
-        if (zlib_dso != NULL) {
-            p_compress = (compress_ft) DSO_bind_func(zlib_dso, "compress");
-            p_inflateEnd
-                = (inflateEnd_ft) DSO_bind_func(zlib_dso, "inflateEnd");
-            p_inflate = (inflate_ft) DSO_bind_func(zlib_dso, "inflate");
-            p_inflateInit_
-                = (inflateInit__ft) DSO_bind_func(zlib_dso, "inflateInit_");
-            p_deflateEnd
-                = (deflateEnd_ft) DSO_bind_func(zlib_dso, "deflateEnd");
-            p_deflate = (deflate_ft) DSO_bind_func(zlib_dso, "deflate");
-            p_deflateInit_
-                = (deflateInit__ft) DSO_bind_func(zlib_dso, "deflateInit_");
-            p_zError = (zError__ft) DSO_bind_func(zlib_dso, "zError");
-
-            if (p_compress && p_inflateEnd && p_inflate
-                && p_inflateInit_ && p_deflateEnd
-                && p_deflate && p_deflateInit_ && p_zError)
-                zlib_loaded++;
-
-            if (!OPENSSL_init_crypto(OPENSSL_INIT_ZLIB, NULL)) {
-                ossl_comp_zlib_cleanup();
-                return meth;
-            }
-            if (zlib_loaded)
-                meth = &zlib_stateful_method;
+    zlib_dso = DSO_load(NULL, LIBZ, NULL, 0);
+    if (zlib_dso != NULL) {
+        p_compress = (compress_ft) DSO_bind_func(zlib_dso, "compress");
+        p_inflateEnd = (inflateEnd_ft) DSO_bind_func(zlib_dso, "inflateEnd");
+        p_inflate = (inflate_ft) DSO_bind_func(zlib_dso, "inflate");
+        p_inflateInit_ = (inflateInit__ft) DSO_bind_func(zlib_dso, "inflateInit_");
+        p_deflateEnd = (deflateEnd_ft) DSO_bind_func(zlib_dso, "deflateEnd");
+        p_deflate = (deflate_ft) DSO_bind_func(zlib_dso, "deflate");
+        p_deflateInit_ = (deflateInit__ft) DSO_bind_func(zlib_dso, "deflateInit_");
+        p_zError = (zError__ft) DSO_bind_func(zlib_dso, "zError");
+
+        if (p_compress == NULL || p_inflateEnd == NULL
+                || p_inflate == NULL || p_inflateInit_ == NULL
+                || p_deflateEnd == NULL || p_deflate == NULL
+                || p_deflateInit_ == NULL || p_zError == NULL) {
+            ossl_comp_zlib_cleanup();
+            return 0;
         }
     }
+# endif
+    return 1;
+}
 #endif
-#if defined(ZLIB)
-    meth = &zlib_stateful_method;
+
+COMP_METHOD *COMP_zlib(void)
+{
+    COMP_METHOD *meth = &zlib_method_nozlib;
+
+#ifdef ZLIB
+    if (RUN_ONCE(&zlib_once, ossl_comp_zlib_init))
+        meth = &zlib_stateful_method;
 #endif
 
     return meth;
 }
 
+/* Also called from OPENSSL_cleanup() */
 void ossl_comp_zlib_cleanup(void)
 {
 #ifdef ZLIB_SHARED
@@ -318,9 +315,9 @@ const BIO_METHOD *BIO_f_zlib(void)
 static int bio_zlib_new(BIO *bi)
 {
     BIO_ZLIB_CTX *ctx;
+
 # ifdef ZLIB_SHARED
-    (void)COMP_zlib();
-    if (!zlib_loaded) {
+    if (!RUN_ONCE(&zlib_once, ossl_comp_zlib_init)) {
         ERR_raise(ERR_LIB_COMP, COMP_R_ZLIB_NOT_SUPPORTED);
         return 0;
     }
@@ -346,6 +343,7 @@ static int bio_zlib_new(BIO *bi)
 static int bio_zlib_free(BIO *bi)
 {
     BIO_ZLIB_CTX *ctx;
+
     if (!bi)
         return 0;
     ctx = BIO_get_data(bi);
@@ -632,6 +630,7 @@ static long bio_zlib_ctrl(BIO *b, int cmd, long num, void *ptr)
 static long bio_zlib_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
 {
     BIO *next = BIO_next(b);
+
     if (next == NULL)
         return 0;
     return BIO_callback_ctrl(next, cmd, fp);