Import of the watch repository from Pebble

tools/clar/clar_sandbox.c

@@ -0,0 +1,147 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+
+static char _clar_path[4096];
+
+static int
+is_valid_tmp_path(const char *path)
+{
+	STAT_T st;
+
+	if (stat(path, &st) != 0)
+		return 0;
+
+	if (!S_ISDIR(st.st_mode))
+		return 0;
+
+	return (access(path, W_OK) == 0);
+}
+
+static int
+find_tmp_path(char *buffer, size_t length)
+{
+#ifndef _WIN32
+	static const size_t var_count = 4;
+	static const char *env_vars[] = {
+		"TMPDIR", "TMP", "TEMP", "USERPROFILE"
+ 	};
+
+ 	size_t i;
+
+	for (i = 0; i < var_count; ++i) {
+		const char *env = getenv(env_vars[i]);
+		if (!env)
+			continue;
+
+		if (is_valid_tmp_path(env)) {
+			strncpy(buffer, env, length);
+			return 0;
+		}
+	}
+
+	/* If the environment doesn't say anything, try to use /tmp */
+	if (is_valid_tmp_path("/tmp")) {
+		strncpy(buffer, "/tmp", length);
+		return 0;
+	}
+
+#else
+	if (GetTempPath((DWORD)length, buffer))
+		return 0;
+#endif
+
+	/* This system doesn't like us, try to use the current directory */
+	if (is_valid_tmp_path(".")) {
+		strncpy(buffer, ".", length);
+		return 0;
+	}
+
+	return -1;
+}
+
+static void clar_unsandbox(void)
+{
+	if (_clar_path[0] == '\0')
+		return;
+
+#ifdef _WIN32
+	chdir("..");
+#endif
+
+	fs_rm(_clar_path);
+}
+
+char *mkdtemp(char *template);
+
+static int build_sandbox_path(void)
+{
+	const char path_tail[] = "clar_tmp_XXXXXX";
+	size_t len;
+
+	if (find_tmp_path(_clar_path, sizeof(_clar_path)) < 0)
+		return -1;
+
+	len = strlen(_clar_path);
+
+#ifdef _WIN32
+	{ /* normalize path to POSIX forward slashes */
+		size_t i;
+		for (i = 0; i < len; ++i) {
+			if (_clar_path[i] == '\\')
+				_clar_path[i] = '/';
+		}
+	}
+#endif
+
+	if (_clar_path[len - 1] != '/') {
+		_clar_path[len++] = '/';
+	}
+
+	strncpy(_clar_path + len, path_tail, sizeof(_clar_path) - len);
+
+#if defined(__MINGW32__)
+	if (_mktemp(_clar_path) == NULL)
+		return -1;
+
+	if (mkdir(_clar_path, 0700) != 0)
+		return -1;
+#elif defined(_WIN32)
+	if (_mktemp_s(_clar_path, sizeof(_clar_path)) != 0)
+		return -1;
+
+	if (mkdir(_clar_path, 0700) != 0)
+		return -1;
+#else
+	if (mkdtemp(_clar_path) == NULL)
+		return -1;
+#endif
+
+	return 0;
+}
+
+static int clar_sandbox(void)
+{
+	if (_clar_path[0] == '\0' && build_sandbox_path() < 0)
+		return -1;
+
+	if (chdir(_clar_path) != 0)
+		return -1;
+
+	return 0;
+}
+