1 /*
2 * Copyright (C) 2019 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 "install/fuse_install.h"
18
19 #include <dirent.h>
20 #include <signal.h>
21 #include <sys/mount.h>
22 #include <sys/stat.h>
23 #include <sys/types.h>
24 #include <sys/wait.h>
25 #include <unistd.h>
26
27 #include <algorithm>
28 #include <functional>
29 #include <memory>
30 #include <string>
31 #include <vector>
32
33 #include <android-base/logging.h>
34 #include <android-base/strings.h>
35
36 #include "bootloader_message/bootloader_message.h"
37 #include "fuse_provider.h"
38 #include "fuse_sideload.h"
39 #include "install/install.h"
40 #include "recovery_utils/roots.h"
41
42 static constexpr const char* SDCARD_ROOT = "/sdcard";
43 // How long (in seconds) we wait for the fuse-provided package file to
44 // appear, before timing out.
45 static constexpr int SDCARD_INSTALL_TIMEOUT = 10;
46
47 // Set the BCB to reboot back into recovery (it won't resume the install from
48 // sdcard though).
SetSdcardUpdateBootloaderMessage()49 static void SetSdcardUpdateBootloaderMessage() {
50 std::vector<std::string> options;
51 std::string err;
52 if (!update_bootloader_message(options, &err)) {
53 LOG(ERROR) << "Failed to set BCB message: " << err;
54 }
55 }
56
57 // Returns the selected filename, or an empty string.
BrowseDirectory(const std::string & path,Device * device,RecoveryUI * ui)58 static std::string BrowseDirectory(const std::string& path, Device* device, RecoveryUI* ui) {
59 ensure_path_mounted(path);
60
61 std::unique_ptr<DIR, decltype(&closedir)> d(opendir(path.c_str()), closedir);
62 if (!d) {
63 PLOG(ERROR) << "error opening " << path;
64 return "";
65 }
66
67 std::vector<std::string> dirs;
68 std::vector<std::string> entries{ "../" }; // "../" is always the first entry.
69
70 dirent* de;
71 while ((de = readdir(d.get())) != nullptr) {
72 std::string name(de->d_name);
73
74 if (de->d_type == DT_DIR) {
75 // Skip "." and ".." entries.
76 if (name == "." || name == "..") continue;
77 dirs.push_back(name + "/");
78 } else if (de->d_type == DT_REG && (android::base::EndsWithIgnoreCase(name, ".zip") ||
79 android::base::EndsWithIgnoreCase(name, ".map"))) {
80 entries.push_back(name);
81 }
82 }
83
84 std::sort(dirs.begin(), dirs.end());
85 std::sort(entries.begin(), entries.end());
86
87 // Append dirs to the entries list.
88 entries.insert(entries.end(), dirs.begin(), dirs.end());
89
90 std::vector<std::string> headers{ "Choose a package to install:", path };
91
92 size_t chosen_item = 0;
93 while (true) {
94 chosen_item = ui->ShowMenu(
95 headers, entries, chosen_item, true,
96 std::bind(&Device::HandleMenuKey, device, std::placeholders::_1, std::placeholders::_2));
97
98 // Return if WaitKey() was interrupted.
99 if (chosen_item == static_cast<size_t>(RecoveryUI::KeyError::INTERRUPTED)) {
100 return "";
101 }
102
103 const std::string& item = entries[chosen_item];
104 if (chosen_item == 0) {
105 // Go up but continue browsing (if the caller is BrowseDirectory).
106 return "";
107 }
108
109 std::string new_path = path + "/" + item;
110 if (new_path.back() == '/') {
111 // Recurse down into a subdirectory.
112 new_path.pop_back();
113 std::string result = BrowseDirectory(new_path, device, ui);
114 if (!result.empty()) return result;
115 } else {
116 // Selected a zip file: return the path to the caller.
117 return new_path;
118 }
119 }
120
121 // Unreachable.
122 }
123
StartInstallPackageFuse(std::string_view path)124 static bool StartInstallPackageFuse(std::string_view path) {
125 if (path.empty()) {
126 return false;
127 }
128
129 constexpr auto FUSE_BLOCK_SIZE = 65536;
130 bool is_block_map = android::base::ConsumePrefix(&path, "@");
131 auto fuse_data_provider =
132 is_block_map ? FuseBlockDataProvider::CreateFromBlockMap(std::string(path), FUSE_BLOCK_SIZE)
133 : FuseFileDataProvider::CreateFromFile(std::string(path), FUSE_BLOCK_SIZE);
134
135 if (!fuse_data_provider || !fuse_data_provider->Valid()) {
136 LOG(ERROR) << "Failed to create fuse data provider.";
137 return false;
138 }
139
140 if (android::base::StartsWith(path, SDCARD_ROOT)) {
141 // The installation process expects to find the sdcard unmounted. Unmount it with MNT_DETACH so
142 // that our open file continues to work but new references see it as unmounted.
143 umount2(SDCARD_ROOT, MNT_DETACH);
144 }
145
146 return run_fuse_sideload(std::move(fuse_data_provider)) == 0;
147 }
148
InstallWithFuseFromPath(std::string_view path,RecoveryUI * ui)149 InstallResult InstallWithFuseFromPath(std::string_view path, RecoveryUI* ui) {
150 // We used to use fuse in a thread as opposed to a process. Since accessing
151 // through fuse involves going from kernel to userspace to kernel, it leads
152 // to deadlock when a page fault occurs. (Bug: 26313124)
153 pid_t child;
154 if ((child = fork()) == 0) {
155 bool status = StartInstallPackageFuse(path);
156
157 _exit(status ? EXIT_SUCCESS : EXIT_FAILURE);
158 }
159
160 // FUSE_SIDELOAD_HOST_PATHNAME will start to exist once the fuse in child process is ready.
161 InstallResult result = INSTALL_ERROR;
162 int status;
163 bool waited = false;
164 for (int i = 0; i < SDCARD_INSTALL_TIMEOUT; ++i) {
165 if (waitpid(child, &status, WNOHANG) == -1) {
166 result = INSTALL_ERROR;
167 waited = true;
168 break;
169 }
170
171 struct stat sb;
172 if (stat(FUSE_SIDELOAD_HOST_PATHNAME, &sb) == -1) {
173 if (errno == ENOENT && i < SDCARD_INSTALL_TIMEOUT - 1) {
174 sleep(1);
175 continue;
176 } else {
177 LOG(ERROR) << "Timed out waiting for the fuse-provided package.";
178 result = INSTALL_ERROR;
179 kill(child, SIGKILL);
180 break;
181 }
182 }
183 auto package =
184 Package::CreateFilePackage(FUSE_SIDELOAD_HOST_PATHNAME,
185 std::bind(&RecoveryUI::SetProgress, ui, std::placeholders::_1));
186 result =
187 InstallPackage(package.get(), FUSE_SIDELOAD_HOST_PATHNAME, false, 0 /* retry_count */, ui);
188 break;
189 }
190
191 if (!waited) {
192 // Calling stat() on this magic filename signals the fuse
193 // filesystem to shut down.
194 struct stat sb;
195 stat(FUSE_SIDELOAD_HOST_EXIT_PATHNAME, &sb);
196
197 waitpid(child, &status, 0);
198 }
199
200 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
201 LOG(ERROR) << "Error exit from the fuse process: " << WEXITSTATUS(status);
202 }
203
204 return result;
205 }
206
ApplyFromSdcard(Device * device)207 InstallResult ApplyFromSdcard(Device* device) {
208 auto ui = device->GetUI();
209 if (ensure_path_mounted(SDCARD_ROOT) != 0) {
210 LOG(ERROR) << "\n-- Couldn't mount " << SDCARD_ROOT << ".\n";
211 return INSTALL_ERROR;
212 }
213
214 std::string path = BrowseDirectory(SDCARD_ROOT, device, ui);
215 if (path.empty()) {
216 LOG(ERROR) << "\n-- No package file selected.\n";
217 ensure_path_unmounted(SDCARD_ROOT);
218 return INSTALL_ERROR;
219 }
220
221 // Hint the install function to read from a block map file.
222 if (android::base::EndsWithIgnoreCase(path, ".map")) {
223 path = "@" + path;
224 }
225
226 ui->Print("\n-- Install %s ...\n", path.c_str());
227 SetSdcardUpdateBootloaderMessage();
228
229 auto result = InstallWithFuseFromPath(path, ui);
230 ensure_path_unmounted(SDCARD_ROOT);
231 return result;
232 }
233