From 4368ae31424f93f3272209ea61847f2406dd23ad Mon Sep 17 00:00:00 2001
From: Paul Sokolovsky <pfalcon@users.sourceforge.net>
Date: Thu, 20 Jul 2017 00:20:53 +0300
Subject: [PATCH] extmod/modussl_axtls: Allow to close ssl stream multiple
 times.

Make sure that 2nd close has no effect and operations on closed streams
are handled properly.
---
 extmod/modussl_axtls.c         | 22 +++++++++++++++++++---
 tests/extmod/ussl_basic.py     |  8 ++++++++
 tests/extmod/ussl_basic.py.exp |  3 ++-
 3 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/extmod/modussl_axtls.c b/extmod/modussl_axtls.c
index a27f0f1fe5..a5ab8896c0 100644
--- a/extmod/modussl_axtls.c
+++ b/extmod/modussl_axtls.c
@@ -102,6 +102,11 @@ STATIC void socket_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kin
 STATIC mp_uint_t socket_read(mp_obj_t o_in, void *buf, mp_uint_t size, int *errcode) {
     mp_obj_ssl_socket_t *o = MP_OBJ_TO_PTR(o_in);
 
+    if (o->ssl_sock == NULL) {
+        *errcode = EBADF;
+        return MP_STREAM_ERROR;
+    }
+
     while (o->bytes_left == 0) {
         mp_int_t r = ssl_read(o->ssl_sock, &o->buf);
         if (r == SSL_OK) {
@@ -131,6 +136,12 @@ STATIC mp_uint_t socket_read(mp_obj_t o_in, void *buf, mp_uint_t size, int *errc
 
 STATIC mp_uint_t socket_write(mp_obj_t o_in, const void *buf, mp_uint_t size, int *errcode) {
     mp_obj_ssl_socket_t *o = MP_OBJ_TO_PTR(o_in);
+
+    if (o->ssl_sock == NULL) {
+        *errcode = EBADF;
+        return MP_STREAM_ERROR;
+    }
+
     mp_int_t r = ssl_write(o->ssl_sock, buf, size);
     if (r < 0) {
         *errcode = r;
@@ -151,9 +162,14 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_2(socket_setblocking_obj, socket_setblocking);
 
 STATIC mp_obj_t socket_close(mp_obj_t self_in) {
     mp_obj_ssl_socket_t *self = MP_OBJ_TO_PTR(self_in);
-    ssl_free(self->ssl_sock);
-    ssl_ctx_free(self->ssl_ctx);
-    return mp_stream_close(self->sock);
+    if (self->ssl_sock != NULL) {
+        ssl_free(self->ssl_sock);
+        ssl_ctx_free(self->ssl_ctx);
+        self->ssl_sock = NULL;
+        return mp_stream_close(self->sock);
+    }
+
+    return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(socket_close_obj, socket_close);
 
diff --git a/tests/extmod/ussl_basic.py b/tests/extmod/ussl_basic.py
index 9f8019a0bc..e8710ed51a 100644
--- a/tests/extmod/ussl_basic.py
+++ b/tests/extmod/ussl_basic.py
@@ -43,6 +43,14 @@ except OSError as er:
 
 # close
 ss.close()
+# close 2nd time
+ss.close()
+
+# read on closed socket
+try:
+    ss.read(10)
+except OSError as er:
+    print('read:', repr(er))
 
 # write on closed socket
 try:
diff --git a/tests/extmod/ussl_basic.py.exp b/tests/extmod/ussl_basic.py.exp
index b4dd038606..cb9c51f7a1 100644
--- a/tests/extmod/ussl_basic.py.exp
+++ b/tests/extmod/ussl_basic.py.exp
@@ -5,4 +5,5 @@ setblocking: NotImplementedError
 4
 b''
 read: OSError(-261,)
-write: OSError(-256,)
+read: OSError(9,)
+write: OSError(9,)