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 <linux/filter.h>
20 #include <linux/prctl.h>
21 #include <netinet/in.h>
22 #include <netinet/tcp.h>
23 #include <sys/mman.h>
24 #include <sys/socket.h>
25 #include <syscall.h>
26
27 #include <vector>
28
29 #include <sandboxed_api/sandbox2/allowlists/unrestricted_networking.h>
30 #include <sandboxed_api/sandbox2/policybuilder.h>
31 #include <sandboxed_api/sandbox2/util/bpf_helper.h>
32 #include <sandboxed_api/util/path.h>
33
34 namespace cuttlefish::process_sandboxer {
35
36 using sapi::file::JoinPath;
37
NetsimdPolicy(const HostInfo & host)38 sandbox2::PolicyBuilder NetsimdPolicy(const HostInfo& host) {
39 return BaselinePolicy(host, host.HostToolExe("netsimd"))
40 .AddDirectory(JoinPath(host.host_artifacts_path, "bin", "netsim-ui"))
41 .AddDirectory(JoinPath(host.runtime_dir, "internal"), /* is_ro= */ false)
42 .AddDirectory(host.tmp_dir, /* is_ro= */ false)
43 .AddFile("/dev/urandom") // For gRPC
44 .AddPolicyOnSyscalls(
45 {__NR_getsockopt, __NR_setsockopt},
46 [](bpf_labels& labels) -> std::vector<sock_filter> {
47 return {
48 ARG_32(1), // level
49 JEQ32(IPPROTO_TCP, JUMP(&labels, cf_netsimd_getsockopt_tcp)),
50 JEQ32(IPPROTO_IPV6, JUMP(&labels, cf_netsimd_getsockopt_ipv6)),
51 JNE32(SOL_SOCKET, JUMP(&labels, cf_netsimd_getsockopt_end)),
52 // SOL_SOCKET
53 ARG_32(2), // optname
54 JEQ32(SO_REUSEADDR, ALLOW),
55 JEQ32(SO_REUSEPORT, ALLOW),
56 JUMP(&labels, cf_netsimd_getsockopt_end),
57 // IPPROTO_TCP
58 LABEL(&labels, cf_netsimd_getsockopt_tcp),
59 ARG_32(2), // optname
60 JEQ32(TCP_NODELAY, ALLOW),
61 JEQ32(TCP_USER_TIMEOUT, ALLOW),
62 JUMP(&labels, cf_netsimd_getsockopt_end),
63 // IPPROTO_IPV6
64 LABEL(&labels, cf_netsimd_getsockopt_ipv6),
65 ARG_32(2), // optname
66 JEQ32(IPV6_V6ONLY, ALLOW),
67 LABEL(&labels, cf_netsimd_getsockopt_end),
68 };
69 })
70 .AddPolicyOnSyscall(__NR_madvise,
71 {ARG_32(2), JEQ32(MADV_DONTNEED, ALLOW)})
72 .AddPolicyOnSyscall(__NR_prctl,
73 {ARG_32(0), JEQ32(PR_CAPBSET_READ, ALLOW)})
74 .AddPolicyOnSyscall(__NR_socket, {ARG_32(0), JEQ32(AF_INET, ALLOW),
75 JEQ32(AF_INET6, ALLOW)})
76 .AddTmpfs("/tmp", 1 << 20)
77 .Allow(sandbox2::UnrestrictedNetworking())
78 .AllowDup()
79 .AllowEpoll()
80 .AllowEpollWait()
81 .AllowEventFd()
82 .AllowHandleSignals()
83 .AllowMkdir()
84 .AllowPipe()
85 .AllowPrctlSetName()
86 .AllowReaddir()
87 .AllowSafeFcntl()
88 .AllowSelect()
89 .AllowSleep()
90 .AllowSyscall(__NR_accept4)
91 .AllowSyscall(__NR_bind)
92 .AllowSyscall(__NR_clone)
93 .AllowSyscall(__NR_getcwd)
94 .AllowSyscall(__NR_getrandom)
95 .AllowSyscall(__NR_getsockname)
96 .AllowSyscall(__NR_listen)
97 .AllowSyscall(__NR_sched_getparam)
98 .AllowSyscall(__NR_sched_getscheduler)
99 .AllowSyscall(__NR_sched_yield)
100 .AllowSyscall(__NR_statx); // Not covered by AllowStat
101 }
102
103 } // namespace cuttlefish::process_sandboxer
104