blob: 8c3df30bf5b05509ba81ed3faf38b64cc44f7d07 [file] [log] [blame]
Paul Crowley82b41ff2017-10-20 08:17:54 -07001/*
2 * Copyright (C) 2017 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/*
18 * Tool to create a directory with the right SELinux context applied, or
19 * apply the context if it's absent. Also fixes mode, uid, gid.
20 */
21
22#include <iostream>
23#include <string>
24#include <vector>
25
26#include <dirent.h>
27#include <stdio.h>
28#include <stdlib.h>
29#include <sys/stat.h>
30#include <sys/types.h>
31
32#include <android-base/logging.h>
33#include <android-base/scopeguard.h>
34
35#include <cutils/fs.h>
36#include <selinux/android.h>
37
38#include "Utils.h"
39#include "android/os/IVold.h"
40
Andreas Huber71cd43f2018-01-22 11:25:29 -080041#include <private/android_filesystem_config.h>
42
Paul Crowley82b41ff2017-10-20 08:17:54 -070043static void usage(const char* progname) {
44 std::cerr << "Usage: " << progname << " [ prepare | destroy ] <volume_uuid> <user_id> <flags>"
45 << std::endl;
46 exit(-1);
47}
48
49static bool small_int(const std::string& s) {
50 return !s.empty() && s.size() < 7 && s.find_first_not_of("0123456789") == std::string::npos;
51}
52
53static bool valid_uuid(const std::string& s) {
54 return s.size() < 40 && s.find_first_not_of("0123456789abcdefABCDEF-_") == std::string::npos;
55}
56
57static bool prepare_dir(struct selabel_handle* sehandle, mode_t mode, uid_t uid, gid_t gid,
58 const std::string& path) {
59 auto clearfscreatecon = android::base::make_scope_guard([] { setfscreatecon(nullptr); });
60 auto secontext = std::unique_ptr<char, void (*)(char*)>(nullptr, freecon);
61 char* tmp_secontext;
62 if (sehandle && selabel_lookup(sehandle, &tmp_secontext, path.c_str(), S_IFDIR) == 0) {
63 secontext.reset(tmp_secontext);
64 }
65 LOG(DEBUG) << "Setting up mode " << std::oct << mode << std::dec << " uid " << uid << " gid "
Roman Kiryanovbda30322018-07-26 13:41:14 -070066 << gid << " context " << (secontext ? secontext.get() : "null")
67 << " on path: " << path;
Paul Crowley82b41ff2017-10-20 08:17:54 -070068 if (secontext) {
69 if (setfscreatecon(secontext.get()) != 0) {
70 PLOG(ERROR) << "Unable to read setfscreatecon for: " << path;
71 return false;
72 }
73 }
74 if (fs_prepare_dir(path.c_str(), mode, uid, gid) != 0) {
75 return false;
76 }
77 if (secontext) {
78 char* tmp_oldsecontext = nullptr;
79 if (lgetfilecon(path.c_str(), &tmp_oldsecontext) < 0) {
80 PLOG(ERROR) << "Unable to read secontext for: " << path;
81 return false;
82 }
83 auto oldsecontext = std::unique_ptr<char, void (*)(char*)>(tmp_oldsecontext, freecon);
84 if (strcmp(secontext.get(), oldsecontext.get()) != 0) {
85 LOG(INFO) << "Relabelling from " << ((char*)oldsecontext.get()) << " to "
86 << ((char*)secontext.get()) << ": " << path;
87 if (lsetfilecon(path.c_str(), secontext.get()) != 0) {
88 PLOG(ERROR) << "Relabelling failed for: " << path;
89 return false;
90 }
91 }
92 }
93 return true;
94}
95
96static bool rmrf_contents(const std::string& path) {
97 auto dirp = std::unique_ptr<DIR, int (*)(DIR*)>(opendir(path.c_str()), closedir);
98 if (!dirp) {
99 PLOG(ERROR) << "Unable to open directory: " << path;
100 return false;
101 }
102 bool res = true;
103 for (;;) {
104 errno = 0;
105 auto const entry = readdir(dirp.get());
106 if (!entry) {
107 if (errno) {
108 PLOG(ERROR) << "readdir failed on: " << path;
109 return false;
110 }
111 return res;
112 }
113 if (entry->d_name[0] == '.') continue;
114 auto subdir = path + "/" + entry->d_name;
115 if (0 !=
116 android::vold::ForkExecvp(std::vector<std::string>{"/system/bin/rm", "-rf", subdir})) {
117 LOG(ERROR) << "rm -rf failed on " << subdir;
118 res = false;
119 }
120 }
121}
122
123static bool prepare_subdirs(const std::string& volume_uuid, int user_id, int flags) {
124 struct selabel_handle* sehandle = selinux_android_file_context_handle();
125
126 if (volume_uuid.empty()) {
127 if (flags & android::os::IVold::STORAGE_FLAG_DE) {
128 auto misc_de_path = android::vold::BuildDataMiscDePath(user_id);
129 if (!prepare_dir(sehandle, 0700, 0, 0, misc_de_path + "/vold")) return false;
Jin Qianf3961442017-10-19 14:44:37 -0700130 if (!prepare_dir(sehandle, 0700, 0, 0, misc_de_path + "/storaged")) return false;
Andreas Huber71cd43f2018-01-22 11:25:29 -0800131
132 auto vendor_de_path = android::vold::BuildDataVendorDePath(user_id);
133 if (!prepare_dir(sehandle, 0700, AID_SYSTEM, AID_SYSTEM, vendor_de_path + "/fpdata")) {
134 return false;
135 }
Paul Crowley82b41ff2017-10-20 08:17:54 -0700136 }
137 if (flags & android::os::IVold::STORAGE_FLAG_CE) {
138 auto misc_ce_path = android::vold::BuildDataMiscCePath(user_id);
139 if (!prepare_dir(sehandle, 0700, 0, 0, misc_ce_path + "/vold")) return false;
Jin Qianf3961442017-10-19 14:44:37 -0700140 if (!prepare_dir(sehandle, 0700, 0, 0, misc_ce_path + "/storaged")) return false;
Paul Crowley82b41ff2017-10-20 08:17:54 -0700141 }
142 }
143 return true;
144}
145
146static bool destroy_subdirs(const std::string& volume_uuid, int user_id, int flags) {
147 bool res = true;
148 if (volume_uuid.empty()) {
149 if (flags & android::os::IVold::STORAGE_FLAG_CE) {
150 auto misc_ce_path = android::vold::BuildDataMiscCePath(user_id);
151 res &= rmrf_contents(misc_ce_path);
Andreas Huber71cd43f2018-01-22 11:25:29 -0800152
153 auto vendor_ce_path = android::vold::BuildDataVendorCePath(user_id);
154 res &= rmrf_contents(vendor_ce_path);
Paul Crowley82b41ff2017-10-20 08:17:54 -0700155 }
156 if (flags & android::os::IVold::STORAGE_FLAG_DE) {
157 auto misc_de_path = android::vold::BuildDataMiscDePath(user_id);
158 res &= rmrf_contents(misc_de_path);
Andreas Huber71cd43f2018-01-22 11:25:29 -0800159
160 auto vendor_de_path = android::vold::BuildDataVendorDePath(user_id);
161 res &= rmrf_contents(vendor_de_path);
Paul Crowley82b41ff2017-10-20 08:17:54 -0700162 }
163 }
164 return res;
165}
166
167int main(int argc, const char* const argv[]) {
168 android::base::InitLogging(const_cast<char**>(argv));
169 std::vector<std::string> args(argv + 1, argv + argc);
170
171 if (args.size() != 4 || !valid_uuid(args[1]) || !small_int(args[2]) || !small_int(args[3])) {
172 usage(argv[0]);
173 return -1;
174 }
175
176 auto volume_uuid = args[1];
177 int user_id = stoi(args[2]);
178 int flags = stoi(args[3]);
179 if (args[0] == "prepare") {
180 if (!prepare_subdirs(volume_uuid, user_id, flags)) return -1;
181 } else if (args[0] == "destroy") {
182 if (!destroy_subdirs(volume_uuid, user_id, flags)) return -1;
183 } else {
184 usage(argv[0]);
185 return -1;
186 }
187 return 0;
188}