Check of return values and proper error handling.

Modules/socketmodule.c

@@ -344,9 +344,12 @@ BUILD_FUNC_DEF_2(makesockaddr,struct sockaddr *,addr, int,addrlen)
 	case AF_INET:
 	{
 		struct sockaddr_in *a = (struct sockaddr_in *) addr;
-		PyObject *addr = makeipaddr(a);
-		PyObject *ret = Py_BuildValue("Oi", addr, ntohs(a->sin_port));
-		Py_XDECREF(addr);
+		PyObject *addrobj = makeipaddr(a);
+		PyObject *ret = NULL;
+		if (addrobj) {
+			ret = Py_BuildValue("Oi", addrobj, ntohs(a->sin_port));
+			Py_DECREF(addrobj);
+		}
 		return ret;
 	}
 
@@ -361,7 +364,8 @@ BUILD_FUNC_DEF_2(makesockaddr,struct sockaddr *,addr, int,addrlen)
 	/* More cases here... */
 
 	default:
-		PyErr_SetString(PySocket_Error, "return unknown socket address type");
+		PyErr_SetString(PySocket_Error,
+				"return unknown socket address type");
 		return NULL;
 
 	}
@@ -389,7 +393,8 @@ getsockaddrarg,PySocketSockObject *,s, PyObject *,args, struct sockaddr **,addr_
 		if (!PyArg_Parse(args, "s#", &path, &len))
 			return 0;
 		if (len > sizeof addr->sun_path) {
-			PyErr_SetString(PySocket_Error, "AF_UNIX path too long");
+			PyErr_SetString(PySocket_Error,
+					"AF_UNIX path too long");
 			return 0;
 		}
 		addr->sun_family = AF_UNIX;
@@ -468,7 +473,10 @@ BUILD_FUNC_DEF_2(PySocketSock_accept,PySocketSockObject *,s, PyObject *,args)
 {
 	char addrbuf[256];
 	int addrlen, newfd;
-	PyObject *sock, *addr, *res;
+	PyObject *sock = NULL;
+	PyObject *addr = NULL;
+	PyObject *res = NULL;
+
 	if (!PyArg_NoArgs(args))
 		return NULL;
 	if (!getsockaddrlen(s, &addrlen))
@@ -478,16 +486,24 @@ BUILD_FUNC_DEF_2(PySocketSock_accept,PySocketSockObject *,s, PyObject *,args)
 	Py_END_ALLOW_THREADS
 	if (newfd < 0)
 		return PySocket_Err();
+
 	/* Create the new object with unspecified family,
 	   to avoid calls to bind() etc. on it. */
 	sock = (PyObject *) PySocketSock_New(newfd,
 					s->sock_family,
 					s->sock_type,
 					s->sock_proto);
-	if (sock == NULL)
+	if (sock == NULL) {
 		close(newfd);
-	addr = makesockaddr((struct sockaddr *) addrbuf, addrlen);
-	res = Py_BuildValue("OO", sock, addr);
+		goto finally;
+	}
+	if (!(addr = makesockaddr((struct sockaddr *) addrbuf, addrlen)))
+		goto finally;
+
+	if (!(res = Py_BuildValue("OO", sock, addr)))
+		goto finally;
+
+  finally:
 	Py_XDECREF(sock);
 	Py_XDECREF(addr);
 	return res;
@@ -543,7 +559,8 @@ BUILD_FUNC_DEF_2(PySocketSock_setsockopt,PySocketSockObject *,s, PyObject *,args
 	}
 	else {
 		PyErr_Clear();
-		if (!PyArg_Parse(args, "(iis#)", &level, &optname, &buf, &buflen))
+		if (!PyArg_Parse(args, "(iis#)", &level, &optname,
+				 &buf, &buflen))
 			return NULL;
 	}
 	res = setsockopt(s->sock_fd, level, optname, (ANY *)buf, buflen);
@@ -581,7 +598,8 @@ BUILD_FUNC_DEF_2(PySocketSock_getsockopt,PySocketSockObject *,s, PyObject *,args
 		return PyInt_FromLong(flag);
 	}
 	if (buflen <= 0 || buflen > 1024) {
-		PyErr_SetString(PySocket_Error, "getsockopt buflen out of range");
+		PyErr_SetString(PySocket_Error,
+				"getsockopt buflen out of range");
 		return NULL;
 	}
 	buf = PyString_FromStringAndSize((char *)NULL, buflen);
@@ -683,9 +701,9 @@ BUILD_FUNC_DEF_2(PySocketSock_dup,PySocketSockObject *,s, PyObject *,args)
 	if (newfd < 0)
 		return PySocket_Err();
 	sock = (PyObject *) PySocketSock_New(newfd,
-					s->sock_family,
-					s->sock_type,
-					s->sock_proto);
+					     s->sock_family,
+					     s->sock_type,
+					     s->sock_proto);
 	if (sock == NULL)
 		close(newfd);
 	return sock;
@@ -825,7 +843,10 @@ static PyObject *
 BUILD_FUNC_DEF_2(PySocketSock_recvfrom,PySocketSockObject *,s, PyObject *,args)
 {
 	char addrbuf[256];
-	PyObject *buf, *addr, *ret;
+	PyObject *buf = NULL;
+	PyObject *addr = NULL;
+	PyObject *ret = NULL;
+
 	int addrlen, len, n, flags = 0;
 	if (!PyArg_ParseTuple(args, "i|i", &len, &flags))
 		return NULL;
@@ -837,10 +858,11 @@ BUILD_FUNC_DEF_2(PySocketSock_recvfrom,PySocketSockObject *,s, PyObject *,args)
 	Py_BEGIN_ALLOW_THREADS
 	n = recvfrom(s->sock_fd, PyString_AsString(buf), len, flags,
 #ifndef MS_WINDOWS
-		     (ANY *)addrbuf, &addrlen);
+		     (ANY *)addrbuf, &addrlen
 #else
-		     (struct sockaddr *)addrbuf, &addrlen);
+		     (struct sockaddr *)addrbuf, &addrlen
 #endif
+		     );
 	Py_END_ALLOW_THREADS
 	if (n < 0) {
 		Py_DECREF(buf);
@@ -848,8 +870,12 @@ BUILD_FUNC_DEF_2(PySocketSock_recvfrom,PySocketSockObject *,s, PyObject *,args)
 	}
 	if (n != len && _PyString_Resize(&buf, n) < 0)
 		return NULL;
-	addr = makesockaddr((struct sockaddr *)addrbuf, addrlen);
+		
+	if (!(addr = makesockaddr((struct sockaddr *)addrbuf, addrlen)))
+		goto finally;
+
 	ret = Py_BuildValue("OO", buf, addr);
+  finally:
 	Py_XDECREF(addr);
 	Py_XDECREF(buf);
 	return ret;
@@ -1073,19 +1099,25 @@ BUILD_FUNC_DEF_2(PySocket_gethostbyaddr,PyObject *,self, PyObject *, args)
 	if ((addr_list = PyList_New(0)) == NULL)
 		goto err;
 	for (pch = h->h_aliases; *pch != NULL; pch++) {
+		int status;
 		tmp = PyString_FromString(*pch);
 		if (tmp == NULL)
 			goto err;
-		PyList_Append(name_list, tmp);
+		status = PyList_Append(name_list, tmp);
 		Py_DECREF(tmp);
+		if (status)
+			goto err;
 	}
 	for (pch = h->h_addr_list; *pch != NULL; pch++) {
+		int status;
 		memcpy((char *) &addr.sin_addr, *pch, h->h_length);
 		tmp = makeipaddr(&addr);
 		if (tmp == NULL)
 			goto err;
-		PyList_Append(addr_list, tmp);
+		status = PyList_Append(addr_list, tmp);
 		Py_DECREF(tmp);
+		if (status)
+			goto err;
 	}
 	rtn_tuple = Py_BuildValue("sOO", h->h_name, name_list, addr_list);
  err:
@@ -1276,20 +1308,18 @@ static PyMethodDef PySocket_methods[] = {
 
 
 /* Convenience routine to export an integer value.
-   For simplicity, errors (which are unlikely anyway) are ignored. */
-
+ *
+ * Since this function is called only from initsocket/init_socket(), any
+ * errors trigger a fatal exception.
+ */
 static void
 BUILD_FUNC_DEF_3(insint,PyObject *,d, char *,name, int,value)
 {
 	PyObject *v = PyInt_FromLong((long) value);
-	if (v == NULL) {
-		/* Don't bother reporting this error */
-		PyErr_Clear();
-	}
-	else {
-		PyDict_SetItemString(d, name, v);
-		Py_DECREF(v);
-	}
+	if (!v || PyDict_SetItemString(d, name, v))
+		Py_FatalError("can't initialize socket module");
+
+	Py_DECREF(v);
 }