1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "idmap2d/Idmap2Service.h"
#include <sys/stat.h> // umask
#include <sys/types.h> // umask
#include <unistd.h>
#include <cerrno>
#include <cstring>
#include <fstream>
#include <memory>
#include <ostream>
#include <string>
#include "android-base/macros.h"
#include "android-base/stringprintf.h"
#include "binder/IPCThreadState.h"
#include "idmap2/BinaryStreamVisitor.h"
#include "idmap2/FileUtils.h"
#include "idmap2/Idmap.h"
#include "idmap2/Policies.h"
#include "idmap2/SysTrace.h"
#include "utils/String8.h"
using android::IPCThreadState;
using android::binder::Status;
using android::idmap2::BinaryStreamVisitor;
using android::idmap2::Idmap;
using android::idmap2::IdmapHeader;
using android::idmap2::PolicyBitmask;
using android::idmap2::utils::kIdmapCacheDir;
using android::idmap2::utils::kIdmapFilePermissionMask;
using android::idmap2::utils::UidHasWriteAccessToPath;
namespace {
Status ok() {
return Status::ok();
}
Status error(const std::string& msg) {
LOG(ERROR) << msg;
return Status::fromExceptionCode(Status::EX_NONE, msg.c_str());
}
PolicyBitmask ConvertAidlArgToPolicyBitmask(int32_t arg) {
return static_cast<PolicyBitmask>(arg);
}
} // namespace
namespace android::os {
Status Idmap2Service::getIdmapPath(const std::string& overlay_apk_path,
int32_t user_id ATTRIBUTE_UNUSED, std::string* _aidl_return) {
assert(_aidl_return);
SYSTRACE << "Idmap2Service::getIdmapPath " << overlay_apk_path;
*_aidl_return = Idmap::CanonicalIdmapPathFor(kIdmapCacheDir, overlay_apk_path);
return ok();
}
Status Idmap2Service::removeIdmap(const std::string& overlay_apk_path,
int32_t user_id ATTRIBUTE_UNUSED, bool* _aidl_return) {
assert(_aidl_return);
SYSTRACE << "Idmap2Service::removeIdmap " << overlay_apk_path;
const uid_t uid = IPCThreadState::self()->getCallingUid();
const std::string idmap_path = Idmap::CanonicalIdmapPathFor(kIdmapCacheDir, overlay_apk_path);
if (!UidHasWriteAccessToPath(uid, idmap_path)) {
*_aidl_return = false;
return error(base::StringPrintf("failed to unlink %s: calling uid %d lacks write access",
idmap_path.c_str(), uid));
}
if (unlink(idmap_path.c_str()) != 0) {
*_aidl_return = false;
return error("failed to unlink " + idmap_path + ": " + strerror(errno));
}
*_aidl_return = true;
return ok();
}
Status Idmap2Service::verifyIdmap(const std::string& overlay_apk_path,
int32_t fulfilled_policies ATTRIBUTE_UNUSED,
bool enforce_overlayable ATTRIBUTE_UNUSED,
int32_t user_id ATTRIBUTE_UNUSED, bool* _aidl_return) {
SYSTRACE << "Idmap2Service::verifyIdmap " << overlay_apk_path;
assert(_aidl_return);
const std::string idmap_path = Idmap::CanonicalIdmapPathFor(kIdmapCacheDir, overlay_apk_path);
std::ifstream fin(idmap_path);
const std::unique_ptr<const IdmapHeader> header = IdmapHeader::FromBinaryStream(fin);
fin.close();
*_aidl_return = header && header->IsUpToDate();
// TODO(b/119328308): Check that the set of fulfilled policies of the overlay has not changed
return ok();
}
Status Idmap2Service::createIdmap(const std::string& target_apk_path,
const std::string& overlay_apk_path, int32_t fulfilled_policies,
bool enforce_overlayable, int32_t user_id ATTRIBUTE_UNUSED,
std::unique_ptr<std::string>* _aidl_return) {
assert(_aidl_return);
SYSTRACE << "Idmap2Service::createIdmap " << target_apk_path << " " << overlay_apk_path;
_aidl_return->reset(nullptr);
const PolicyBitmask policy_bitmask = ConvertAidlArgToPolicyBitmask(fulfilled_policies);
const std::string idmap_path = Idmap::CanonicalIdmapPathFor(kIdmapCacheDir, overlay_apk_path);
const uid_t uid = IPCThreadState::self()->getCallingUid();
if (!UidHasWriteAccessToPath(uid, idmap_path)) {
return error(base::StringPrintf("will not write to %s: calling uid %d lacks write accesss",
idmap_path.c_str(), uid));
}
const std::unique_ptr<const ApkAssets> target_apk = ApkAssets::Load(target_apk_path);
if (!target_apk) {
return error("failed to load apk " + target_apk_path);
}
const std::unique_ptr<const ApkAssets> overlay_apk = ApkAssets::Load(overlay_apk_path);
if (!overlay_apk) {
return error("failed to load apk " + overlay_apk_path);
}
const auto idmap = Idmap::FromApkAssets(target_apk_path, *target_apk, overlay_apk_path,
*overlay_apk, policy_bitmask, enforce_overlayable);
if (!idmap) {
return error(idmap.GetErrorMessage());
}
umask(kIdmapFilePermissionMask);
std::ofstream fout(idmap_path);
if (fout.fail()) {
return error("failed to open idmap path " + idmap_path);
}
BinaryStreamVisitor visitor(fout);
(*idmap)->accept(&visitor);
fout.close();
if (fout.fail()) {
return error("failed to write to idmap path " + idmap_path);
}
*_aidl_return = std::make_unique<std::string>(idmap_path);
return ok();
}
} // namespace android::os
|
