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Diffstat (limited to 'sandbox/linux/syscall_broker/broker_file_permission.h')
| -rw-r--r-- | sandbox/linux/syscall_broker/broker_file_permission.h | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/sandbox/linux/syscall_broker/broker_file_permission.h b/sandbox/linux/syscall_broker/broker_file_permission.h new file mode 100644 index 0000000000..03300d1d74 --- /dev/null +++ b/sandbox/linux/syscall_broker/broker_file_permission.h @@ -0,0 +1,119 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#ifndef SANDBOX_LINUX_SYSCALL_BROKER_BROKER_FILE_PERMISSION_H_ +#define SANDBOX_LINUX_SYSCALL_BROKER_BROKER_FILE_PERMISSION_H_ + +#include <string> + +#include "base/macros.h" +#include "sandbox/sandbox_export.h" + +namespace sandbox { + +namespace syscall_broker { + +// BrokerFilePermission defines a path for whitelisting. +// Pick the correct static factory method to create a permission. +// CheckOpen and CheckAccess are async signal safe. +// Constuction and Destruction are not async signal safe. +// |path| is the path to be whitelisted. +class SANDBOX_EXPORT BrokerFilePermission { + public: + ~BrokerFilePermission() {} + BrokerFilePermission(const BrokerFilePermission&) = default; + BrokerFilePermission& operator=(const BrokerFilePermission&) = default; + + static BrokerFilePermission ReadOnly(const std::string& path) { + return BrokerFilePermission(path, false, false, true, false, false); + } + + static BrokerFilePermission ReadOnlyRecursive(const std::string& path) { + return BrokerFilePermission(path, true, false, true, false, false); + } + + static BrokerFilePermission WriteOnly(const std::string& path) { + return BrokerFilePermission(path, false, false, false, true, false); + } + + static BrokerFilePermission ReadWrite(const std::string& path) { + return BrokerFilePermission(path, false, false, true, true, false); + } + + static BrokerFilePermission ReadWriteCreate(const std::string& path) { + return BrokerFilePermission(path, false, false, true, true, true); + } + + static BrokerFilePermission ReadWriteCreateUnlink(const std::string& path) { + return BrokerFilePermission(path, false, true, true, true, true); + } + + static BrokerFilePermission ReadWriteCreateUnlinkRecursive( + const std::string& path) { + return BrokerFilePermission(path, true, true, true, true, true); + } + + // Returns true if |requested_filename| is allowed to be opened + // by this permission. + // If |file_to_open| is not NULL it is set to point to either + // the |requested_filename| in the case of a recursive match, + // or a pointer the matched path in the whitelist if an absolute + // match. + // If not NULL |unlink_after_open| is set to point to true if the + // caller should unlink the path after openning. + // Async signal safe if |file_to_open| is NULL. + bool CheckOpen(const char* requested_filename, + int flags, + const char** file_to_open, + bool* unlink_after_open) const; + // Returns true if |requested_filename| is allowed to be accessed + // by this permission as per access(2). + // If |file_to_open| is not NULL it is set to point to either + // the |requested_filename| in the case of a recursive match, + // or a pointer to the matched path in the whitelist if an absolute + // match. + // |mode| is per mode argument of access(2). + // Async signal safe if |file_to_access| is NULL + bool CheckAccess(const char* requested_filename, + int mode, + const char** file_to_access) const; + + private: + friend class BrokerFilePermissionTester; + BrokerFilePermission(const std::string& path, + bool recursive, + bool unlink, + bool allow_read, + bool allow_write, + bool allow_create); + + // ValidatePath checks |path| and returns true if these conditions are met + // * Greater than 0 length + // * Is an absolute path + // * No trailing slash + // * No /../ path traversal + static bool ValidatePath(const char* path); + + // MatchPath returns true if |requested_filename| is covered by this instance + bool MatchPath(const char* requested_filename) const; + + // Used in by BrokerFilePermissionTester for tests. + static const char* GetErrorMessageForTests(); + + // These are not const as std::vector requires copy-assignment and this class + // is stored in vectors. All methods are marked const so + // the compiler will still enforce no changes outside of the constructor. + std::string path_; + bool recursive_; // Allow everything under this path. |path| must be a dir. + bool unlink_; // unlink after opening. + bool allow_read_; + bool allow_write_; + bool allow_create_; +}; + +} // namespace syscall_broker + +} // namespace sandbox + +#endif // SANDBOX_LINUX_SYSCALL_BROKER_BROKER_FILE_PERMISSION_H_
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