| // 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_CLIENT_H_ |
| #define SANDBOX_LINUX_SYSCALL_BROKER_BROKER_CLIENT_H_ |
| |
| #include "base/macros.h" |
| #include "sandbox/linux/syscall_broker/broker_channel.h" |
| #include "sandbox/linux/syscall_broker/broker_common.h" |
| |
| namespace sandbox { |
| |
| namespace syscall_broker { |
| |
| class BrokerPolicy; |
| |
| // This class can be embedded in a sandboxed process and can be |
| // used to perform certain system calls in another, presumably |
| // non-sandboxed process (which embeds BrokerHost). |
| // A key feature of this class is the ability to use some of its methods in a |
| // thread-safe and async-signal safe way. The goal is to be able to use it to |
| // replace the open() or access() system calls happening anywhere in a process |
| // (as allowed for instance by seccomp-bpf's SIGSYS mechanism). |
| class BrokerClient { |
| public: |
| // |policy| needs to match the policy used by BrokerHost. This |
| // allows to predict some of the requests which will be denied |
| // and save an IPC round trip. |
| // |ipc_channel| needs to be a suitable SOCK_SEQPACKET unix socket. |
| // |fast_check_in_client| should be set to true and |
| // |quiet_failures_for_tests| to false unless you are writing tests. |
| BrokerClient(const BrokerPolicy& policy, |
| BrokerChannel::EndPoint ipc_channel, |
| bool fast_check_in_client, |
| bool quiet_failures_for_tests); |
| ~BrokerClient(); |
| |
| // Can be used in place of access(). |
| // X_OK will always return an error in practice since the broker process |
| // doesn't support execute permissions. |
| // It's similar to the access() system call and will return -errno on errors. |
| // This is async signal safe. |
| int Access(const char* pathname, int mode) const; |
| // Can be used in place of open(). |
| // The implementation only supports certain white listed flags and will |
| // return -EPERM on other flags. |
| // It's similar to the open() system call and will return -errno on errors. |
| // This is async signal safe. |
| int Open(const char* pathname, int flags) const; |
| |
| // Get the file descriptor used for IPC. This is used for tests. |
| int GetIPCDescriptor() const { return ipc_channel_.get(); } |
| |
| private: |
| const BrokerPolicy& broker_policy_; |
| const BrokerChannel::EndPoint ipc_channel_; |
| const bool fast_check_in_client_; // Whether to forward a request that we |
| // know will be denied to the broker. (Used |
| // for tests). |
| const bool quiet_failures_for_tests_; // Disable certain error message when |
| // testing for failures. |
| |
| int PathAndFlagsSyscall(IPCCommand syscall_type, |
| const char* pathname, |
| int flags) const; |
| |
| DISALLOW_COPY_AND_ASSIGN(BrokerClient); |
| }; |
| |
| } // namespace syscall_broker |
| |
| } // namespace sandbox |
| |
| #endif // SANDBOX_LINUX_SYSCALL_BROKER_BROKER_CLIENT_H_ |