bpo-42333: Port _ssl extension to multiphase initialization (PEP 489) (GH-23253)

- Introduce sslmodule_slots
- Introduce sslmodulestate
- Use sslmodulestate
- Get rid of PyState_FindModule
- Move new structs and helpers to header file
- Use macros to access state
- Keep a strong ref to socket type

Misc/NEWS.d/next/Library/2021-04-17-19-31-17.bpo-42333.cgbtZO.rst

@@ -0,0 +1 @@
+Port ``_ssl`` extension module to multiphase initialization.

Modules/_ssl.h

@@ -0,0 +1,45 @@
+#ifndef Py_SSL_H
+#define Py_SSL_H
+
+/*
+ * ssl module state
+ */
+typedef struct {
+    /* Types */
+    PyTypeObject *PySSLContext_Type;
+    PyTypeObject *PySSLSocket_Type;
+    PyTypeObject *PySSLMemoryBIO_Type;
+    PyTypeObject *PySSLSession_Type;
+    /* SSL error object */
+    PyObject *PySSLErrorObject;
+    PyObject *PySSLCertVerificationErrorObject;
+    PyObject *PySSLZeroReturnErrorObject;
+    PyObject *PySSLWantReadErrorObject;
+    PyObject *PySSLWantWriteErrorObject;
+    PyObject *PySSLSyscallErrorObject;
+    PyObject *PySSLEOFErrorObject;
+    /* Error mappings */
+    PyObject *err_codes_to_names;
+    PyObject *err_names_to_codes;
+    PyObject *lib_codes_to_names;
+    /* socket type from module CAPI */
+    PyTypeObject *Sock_Type;
+} _sslmodulestate;
+
+static struct PyModuleDef _sslmodule_def;
+
+Py_LOCAL_INLINE(_sslmodulestate*)
+get_ssl_state(PyObject *module)
+{
+    void *state = PyModule_GetState(module);
+    assert(state != NULL);
+    return (_sslmodulestate *)state;
+}
+
+#define get_state_type(type) \
+    (get_ssl_state(_PyType_GetModuleByDef(type, &_sslmodule_def)))
+#define get_state_ctx(c) (((PySSLContext *)(c))->state)
+#define get_state_sock(s) (((PySSLSocket *)(s))->ctx->state)
+#define get_state_mbio(b) ((_sslmodulestate *)PyType_GetModuleState(Py_TYPE(b)))
+
+#endif /* Py_SSL_H */

Modules/_ssl/debughelpers.c

@@ -21,7 +21,7 @@ _PySSL_msg_callback(int write_p, int version, int content_type,
     threadstate = PyGILState_Ensure();
 
     ssl_obj = (PySSLSocket *)SSL_get_app_data(ssl);
-    assert(PySSLSocket_Check(ssl_obj));
+    assert(Py_IS_TYPE(ssl_obj, get_state_sock(ssl_obj)->PySSLSocket_Type));
     if (ssl_obj->ctx->msg_cb == NULL) {
         PyGILState_Release(threadstate);
         return;
@@ -125,7 +125,7 @@ _PySSL_keylog_callback(const SSL *ssl, const char *line)
     threadstate = PyGILState_Ensure();
 
     ssl_obj = (PySSLSocket *)SSL_get_app_data(ssl);
-    assert(PySSLSocket_Check(ssl_obj));
+    assert(Py_IS_TYPE(ssl_obj, get_state_sock(ssl_obj)->PySSLSocket_Type));
     if (ssl_obj->ctx->keylog_bio == NULL) {
         return;
     }
@@ -199,7 +199,7 @@ _PySSLContext_set_keylog_filename(PySSLContext *self, PyObject *arg, void *c) {
 
     self->keylog_bio = BIO_new_fp(fp, BIO_CLOSE | BIO_FP_TEXT);
     if (self->keylog_bio == NULL) {
-        PyErr_SetString(PySSLErrorObject,
+        PyErr_SetString(get_state_ctx(self)->PySSLErrorObject,
                         "Can't malloc memory for keylog file");
         return -1;
     }

Modules/clinic/_ssl.c.h

@@ -374,7 +374,7 @@ _ssl__SSLContext(PyTypeObject *type, PyObject *args, PyObject *kwargs)
     PyObject *return_value = NULL;
     int proto_version;
 
-    if ((type == PySSLContext_Type) &&
+    if ((type == get_state_type(type)->PySSLContext_Type) &&
         !_PyArg_NoKeywords("_SSLContext", kwargs)) {
         goto exit;
     }
@@ -619,8 +619,8 @@ _ssl__SSLContext__wrap_socket(PySSLContext *self, PyObject *const *args, Py_ssiz
     if (!args) {
         goto exit;
     }
-    if (!PyObject_TypeCheck(args[0], PySocketModule.Sock_Type)) {
-        _PyArg_BadArgument("_wrap_socket", "argument 'sock'", (PySocketModule.Sock_Type)->tp_name, args[0]);
+    if (!PyObject_TypeCheck(args[0], get_state_ctx(self)->Sock_Type)) {
+        _PyArg_BadArgument("_wrap_socket", "argument 'sock'", (get_state_ctx(self)->Sock_Type)->tp_name, args[0]);
         goto exit;
     }
     sock = args[0];
@@ -689,13 +689,13 @@ _ssl__SSLContext__wrap_bio(PySSLContext *self, PyObject *const *args, Py_ssize_t
     if (!args) {
         goto exit;
     }
-    if (!PyObject_TypeCheck(args[0], PySSLMemoryBIO_Type)) {
-        _PyArg_BadArgument("_wrap_bio", "argument 'incoming'", (PySSLMemoryBIO_Type)->tp_name, args[0]);
+    if (!PyObject_TypeCheck(args[0], get_state_ctx(self)->PySSLMemoryBIO_Type)) {
+        _PyArg_BadArgument("_wrap_bio", "argument 'incoming'", (get_state_ctx(self)->PySSLMemoryBIO_Type)->tp_name, args[0]);
         goto exit;
     }
     incoming = (PySSLMemoryBIO *)args[0];
-    if (!PyObject_TypeCheck(args[1], PySSLMemoryBIO_Type)) {
-        _PyArg_BadArgument("_wrap_bio", "argument 'outgoing'", (PySSLMemoryBIO_Type)->tp_name, args[1]);
+    if (!PyObject_TypeCheck(args[1], get_state_ctx(self)->PySSLMemoryBIO_Type)) {
+        _PyArg_BadArgument("_wrap_bio", "argument 'outgoing'", (get_state_ctx(self)->PySSLMemoryBIO_Type)->tp_name, args[1]);
         goto exit;
     }
     outgoing = (PySSLMemoryBIO *)args[1];
@@ -850,11 +850,11 @@ _ssl_MemoryBIO(PyTypeObject *type, PyObject *args, PyObject *kwargs)
 {
     PyObject *return_value = NULL;
 
-    if ((type == PySSLMemoryBIO_Type) &&
+    if ((type == get_state_type(type)->PySSLMemoryBIO_Type) &&
         !_PyArg_NoPositional("MemoryBIO", args)) {
         goto exit;
     }
-    if ((type == PySSLMemoryBIO_Type) &&
+    if ((type == get_state_type(type)->PySSLMemoryBIO_Type) &&
         !_PyArg_NoKeywords("MemoryBIO", kwargs)) {
         goto exit;
     }
@@ -1324,4 +1324,4 @@ exit:
 #ifndef _SSL_ENUM_CRLS_METHODDEF
     #define _SSL_ENUM_CRLS_METHODDEF
 #endif /* !defined(_SSL_ENUM_CRLS_METHODDEF) */
-/*[clinic end generated code: output=ae3d1851daba6562 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=83e68c77bd96789a input=a9049054013a1b77]*/

setup.py

@@ -2428,14 +2428,6 @@ class PyBuildExt(build_ext):
             self.missing.extend(['_ssl', '_hashlib'])
             return None, None
 
-        self.add(Extension(
-            '_ssl', ['_ssl.c'],
-            include_dirs=openssl_includes,
-            library_dirs=openssl_libdirs,
-            libraries=openssl_libs,
-            depends=['socketmodule.h', '_ssl/debughelpers.c'])
-        )
-
         if openssl_rpath == 'auto':
             runtime_library_dirs = openssl_libdirs[:]
         elif not openssl_rpath:
@@ -2469,7 +2461,7 @@ class PyBuildExt(build_ext):
             Extension(
                 '_ssl',
                 ['_ssl.c'],
-                depends=['socketmodule.h', '_ssl/debughelpers.c'],
+                depends=['socketmodule.h', '_ssl/debughelpers.c', '_ssl.h'],
                 **openssl_extension_kwargs
             )
         )