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/sockios.h>
20 #include <netinet/in.h>
21 #include <netinet/tcp.h>
22 #include <sys/ioctl.h>
23 #include <sys/mman.h>
24 #include <sys/prctl.h>
25 #include <sys/socket.h>
26 #include <syscall.h>
27
28 #include <sandboxed_api/sandbox2/allow_unrestricted_networking.h>
29 #include <sandboxed_api/sandbox2/policybuilder.h>
30 #include <sandboxed_api/sandbox2/util/bpf_helper.h>
31
32 #include "host/commands/process_sandboxer/filesystem.h"
33
34 namespace cuttlefish::process_sandboxer {
35
WebRtcPolicy(const HostInfo & host)36 sandbox2::PolicyBuilder WebRtcPolicy(const HostInfo& host) {
37 return BaselinePolicy(host, host.HostToolExe("webRTC"))
38 .AddDirectory(host.log_dir, /* is_ro= */ false)
39 .AddDirectory(
40 JoinPath(host.host_artifacts_path, "/usr/share/webrtc/assets"))
41 .AddDirectory(host.instance_uds_dir, /* is_ro= */ false)
42 .AddDirectory(host.vsock_device_dir, /* is_ro= */ false)
43 .AddDirectory(JoinPath(host.runtime_dir, "recording"), /* is_ro= */ false)
44 .AddFile(host.cuttlefish_config_path)
45 .AddFile("/dev/urandom")
46 .AddFile("/run/cuttlefish/operator")
47 // Shared memory with crosvm for audio
48 .AddPolicyOnMmap([](bpf_labels& labels) -> std::vector<sock_filter> {
49 return {
50 ARG_32(2), // prot
51 JNE32(PROT_READ | PROT_WRITE, JUMP(&labels, cf_webrtc_mmap_end)),
52 ARG_32(3), // flags
53 JEQ32(MAP_SHARED, ALLOW),
54 LABEL(&labels, cf_webrtc_mmap_end),
55 };
56 })
57 .AddPolicyOnSyscall(
58 __NR_getsockopt,
59 [](bpf_labels& labels) -> std::vector<sock_filter> {
60 return {
61 ARG_32(1), // level
62 JNE32(SOL_SOCKET, JUMP(&labels, cf_webrtc_getsockopt_end)),
63 ARG_32(2), // optname
64 JEQ32(SO_ERROR, ALLOW),
65 JEQ32(SO_PEERCRED, ALLOW),
66 LABEL(&labels, cf_webrtc_getsockopt_end),
67 };
68 })
69 .AddPolicyOnSyscall(__NR_ioctl, {ARG_32(1), JEQ32(SIOCGSTAMP, ALLOW),
70 JEQ32(FIONREAD, ALLOW)})
71 .AddPolicyOnSyscall(__NR_madvise,
72 {ARG_32(2), JEQ32(MADV_WIPEONFORK, ALLOW),
73 JEQ32(MADV_DONTNEED, ALLOW),
74 // TODO: schuffelen - find out what this is
75 JEQ32(0xffffffff, ALLOW)})
76 .AddPolicyOnSyscall(__NR_prctl,
77 {ARG_32(0), JEQ32(PR_CAPBSET_READ, ALLOW)})
78 .AddPolicyOnSyscall(
79 __NR_setsockopt,
80 [](bpf_labels& labels) -> std::vector<sock_filter> {
81 return {
82 ARG_32(1), // level
83 JEQ32(SOL_IP, JUMP(&labels, cf_webrtc_setsockopt_ip)),
84 JEQ32(SOL_IPV6, JUMP(&labels, cf_webrtc_setsockopt_ipv6)),
85 JEQ32(SOL_SOCKET, JUMP(&labels, cf_webrtc_setsockopt_sol)),
86 JNE32(IPPROTO_TCP, JUMP(&labels, cf_webrtc_setsockopt_end)),
87 // IPPROTO_TCP
88 ARG_32(2), // optname
89 JEQ32(TCP_NODELAY, ALLOW),
90 JUMP(&labels, cf_webrtc_setsockopt_end),
91 // SOL_IP
92 LABEL(&labels, cf_webrtc_setsockopt_ip),
93 ARG_32(2), // optname
94 JEQ32(IP_RECVERR, ALLOW),
95 JEQ32(IP_TOS, ALLOW),
96 JEQ32(IP_RETOPTS, ALLOW),
97 JEQ32(IP_PKTINFO, ALLOW),
98 JUMP(&labels, cf_webrtc_setsockopt_end),
99 // SOL_IPV6
100 LABEL(&labels, cf_webrtc_setsockopt_ipv6),
101 ARG_32(2), // optname
102 JEQ32(IPV6_TCLASS, ALLOW),
103 JUMP(&labels, cf_webrtc_setsockopt_end),
104 // SOL_SOCKET
105 LABEL(&labels, cf_webrtc_setsockopt_sol),
106 ARG_32(2), // optname
107 JEQ32(SO_REUSEADDR, ALLOW),
108 JEQ32(SO_SNDBUF, ALLOW),
109 JEQ32(SO_RCVBUF, ALLOW),
110 LABEL(&labels, cf_webrtc_setsockopt_end),
111 };
112 })
113 .AddPolicyOnSyscall(
114 __NR_socket, {ARG_32(0), JEQ32(AF_INET, ALLOW), JEQ32(AF_UNIX, ALLOW),
115 JEQ32(AF_INET6, ALLOW),
116 // webrtc/rtc_base/ifaddrs_android.cc
117 JEQ32(AF_NETLINK, ALLOW), JEQ32(AF_VSOCK, ALLOW)})
118 .Allow(sandbox2::UnrestrictedNetworking())
119 .AllowEpoll()
120 .AllowEpollWait()
121 .AllowEventFd()
122 .AllowGetIDs()
123 .AllowHandleSignals()
124 .AllowPipe()
125 .AllowPrctlSetName()
126 .AllowSafeFcntl()
127 .AllowSelect()
128 .AllowSleep()
129 .AllowSyscall(__NR_accept)
130 .AllowSyscall(__NR_accept4)
131 .AllowSyscall(__NR_bind)
132 .AllowSyscall(__NR_clone) // Multithreading
133 .AllowSyscall(__NR_connect)
134 .AllowSyscall(__NR_ftruncate)
135 .AllowSyscall(__NR_getpeername)
136 .AllowSyscall(__NR_getsockname)
137 .AllowSyscall(__NR_listen)
138 .AllowSyscall(__NR_memfd_create)
139 .AllowSyscall(__NR_recvfrom)
140 .AllowSyscall(__NR_recvmsg)
141 .AllowSyscall(__NR_sched_get_priority_max)
142 .AllowSyscall(__NR_sched_get_priority_min)
143 .AllowSyscall(__NR_sched_getparam)
144 .AllowSyscall(__NR_sched_getscheduler)
145 .AllowSyscall(__NR_sched_setscheduler)
146 .AllowSyscall(__NR_sched_yield)
147 .AllowSyscall(__NR_sendmsg)
148 .AllowSyscall(__NR_sendmmsg)
149 .AllowSyscall(__NR_sendto)
150 .AllowSyscall(__NR_shutdown)
151 .AllowSyscall(__NR_socketpair)
152 .AllowTCGETS();
153 }
154
155 } // namespace cuttlefish::process_sandboxer
156