1 files changed, 32 insertions, 0 deletions
diff --git a/crypto/bio/b_sock.c b/crypto/bio/b_sock.c
index 3e17bec14a..4ae08d2d84 100644
--- a/crypto/bio/b_sock.c
+++ b/crypto/bio/b_sock.c
@@ -379,8 +379,40 @@ int BIO_socket_nbio(int s, int mode)
 
     l = mode;
 # ifdef FIONBIO
+    l = mode;
+
     ret = BIO_socket_ioctl(s, FIONBIO, &l);
+# elif defined(F_GETFL) && defined(F_SETFL) && (defined(O_NONBLOCK) || defined(FNDELAY))
+    /* make sure this call always pushes an error level; BIO_socket_ioctl() does so, so we do too. */
+
+    l = fcntl(s, F_GETFL, 0);
+    if (l == -1) {
+        SYSerr(SYS_F_FCNTL, get_last_rtl_error());
+        ret = -1;
+    } else {
+#  if defined(O_NONBLOCK)
+        l &= ~O_NONBLOCK;
+#  else
+        l &= ~FNDELAY; /* BSD4.x */
+#  endif
+        if (mode) {
+#  if defined(O_NONBLOCK)
+            l |= O_NONBLOCK;
+#  else
+            l |= FNDELAY; /* BSD4.x */
+#  endif
+        }
+        ret = fcntl(s, F_SETFL, l);
+
+        if (ret < 0) {
+            SYSerr(SYS_F_FCNTL, get_last_rtl_error());
+        }
+    }
+# else
+    /* make sure this call always pushes an error level; BIO_socket_ioctl() does so, so we do too. */
+    BIOerr(BIO_F_BIO_SOCKET_NBIO, ERR_R_PASSED_INVALID_ARGUMENT);
 # endif
+
     return (ret == 0);
 }