common: fix #248 TLS on FreeBSD

According to document[1][2][3], retry when SSL_get_error returns
SSL_ERROR_WANT_READ/SSL_ERROR_WANT_WRITE.

[1] https://www.openssl.org/docs/ssl/SSL_read.html
[2] https://www.openssl.org/docs/ssl/SSL_write.html
[3] https://www.openssl.org/docs/ssl/SSL_accept.html

common/ssl_calls.c

@@ -669,6 +669,7 @@ ssl_tls_accept(struct ssl_tls *self)
         return 1;
     }
 
+    while(1) {
         connection_status = SSL_accept(self->ssl);
 
         if (connection_status <= 0)
@@ -677,6 +678,16 @@ ssl_tls_accept(struct ssl_tls *self)
             {
                 return 1;
             }
+            /**
+             * retry when SSL_get_error returns:
+             *     SSL_ERROR_WANT_READ
+             *     SSL_ERROR_WANT_WRITE
+             */
+        }
+        else
+        {
+            break;
+        }
     }
 
     g_writeln("ssl_tls_accept: TLS connection accepted");
@@ -709,6 +720,11 @@ ssl_tls_disconnect(struct ssl_tls *self)
             {
                 return 1;
             }
+            /**
+             * retry when SSL_get_error returns:
+             *     SSL_ERROR_WANT_READ
+             *     SSL_ERROR_WANT_WRITE
+             */
         }
     }
     return 0;
@@ -737,25 +753,39 @@ int APP_CC
 ssl_tls_read(struct ssl_tls *tls, char *data, int length)
 {
     int status;
+    int break_flag;
 
+    while(1) {
         status = SSL_read(tls->ssl, data, length);
 
         switch (SSL_get_error(tls->ssl, status))
         {
             case SSL_ERROR_NONE:
+                break_flag = 1;
                 break;
 
             case SSL_ERROR_WANT_READ:
             case SSL_ERROR_WANT_WRITE:
-            status = 0;
+                /**
-            break;
+                 * retry when SSL_get_error returns:
+                 *     SSL_ERROR_WANT_READ
+                 *     SSL_ERROR_WANT_WRITE
+                 */
+                continue;
 
             default:
                 ssl_tls_print_error("SSL_read", tls->ssl, status);
                 status = -1;
+                break_flag = 1;
                 break;
         }
 
+        if (break_flag)
+        {
+            break;
+        }
+    }
+
     if (SSL_pending(tls->ssl) > 0)
     {
         g_set_wait_obj(tls->rwo);
@@ -769,24 +799,38 @@ int APP_CC
 ssl_tls_write(struct ssl_tls *tls, const char *data, int length)
 {
     int status;
+    int break_flag;
 
+    while(1) {
         status = SSL_write(tls->ssl, data, length);
 
         switch (SSL_get_error(tls->ssl, status))
         {
             case SSL_ERROR_NONE:
+                break_flag = 1;
                 break;
 
             case SSL_ERROR_WANT_READ:
             case SSL_ERROR_WANT_WRITE:
-            status = 0;
+                /**
-            break;
+                 * retry when SSL_get_error returns:
+                 *     SSL_ERROR_WANT_READ
+                 *     SSL_ERROR_WANT_WRITE
+                 */
+                continue;
 
             default:
                 ssl_tls_print_error("SSL_write", tls->ssl, status);
                 status = -1;
+                break_flag = 1;
+                break;
+        }
+
+        if (break_flag)
+        {
             break;
         }
+    }
 
     return status;
 }