1 /*
2  * Copyright (C) 2024 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "host/commands/process_sandboxer/policies.h"
18 
19 #include <syscall.h>
20 
21 #include <sandboxed_api/sandbox2/policybuilder.h>
22 #include <sandboxed_api/sandbox2/util/bpf_helper.h>
23 
24 #include "host/commands/process_sandboxer/filesystem.h"
25 
26 namespace cuttlefish::process_sandboxer {
27 
ModemSimulatorPolicy(const HostInfo & host)28 sandbox2::PolicyBuilder ModemSimulatorPolicy(const HostInfo& host) {
29   return BaselinePolicy(host, host.HostToolExe("modem_simulator"))
30       .AddDirectory(JoinPath(host.host_artifacts_path, "/etc/modem_simulator"))
31       .AddDirectory(host.log_dir, /* is_ro= */ false)
32       .AddDirectory(host.runtime_dir, /* is_ro= */ false)  // modem_nvram.json
33       .AddFile(host.cuttlefish_config_path)
34       .AddPolicyOnSyscall(
35           __NR_setsockopt,
36           [](bpf_labels& labels) -> std::vector<sock_filter> {
37             return {
38                 ARG_32(1),
39                 JNE32(SOL_SOCKET, JUMP(&labels, cf_setsockopt_end)),
40                 ARG_32(2),
41                 JEQ32(SO_REUSEADDR, ALLOW),
42                 LABEL(&labels, cf_setsockopt_end),
43             };
44           })
45       .AddPolicyOnSyscall(__NR_socket, {ARG_32(0), JEQ32(AF_UNIX, ALLOW)})
46       .AllowHandleSignals()
47       .AllowPipe()
48       .AllowSafeFcntl()
49       .AllowSelect()
50       .AllowSyscall(__NR_accept)
51       .AllowSyscall(__NR_bind)
52       .AllowSyscall(__NR_clone)  // multithreading
53       .AllowSyscall(__NR_listen)
54       .AllowTCGETS();
55 }
56 
57 }  // namespace cuttlefish::process_sandboxer
58