1 //
2 // Copyright (C) 2018 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_init_verifier.h"
18 
19 #include <errno.h>
20 #include <getopt.h>
21 #include <pwd.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 
25 #include <fstream>
26 #include <iostream>
27 #include <iterator>
28 #include <string>
29 #include <vector>
30 
31 #include <android-base/file.h>
32 #include <android-base/logging.h>
33 #include <android-base/parseint.h>
34 #include <android-base/strings.h>
35 #include <generated_android_ids.h>
36 #include <hidl/metadata.h>
37 #include <property_info_serializer/property_info_serializer.h>
38 
39 #include "action.h"
40 #include "action_manager.h"
41 #include "action_parser.h"
42 #include "check_builtins.h"
43 #include "host_import_parser.h"
44 #include "host_init_stubs.h"
45 #include "interface_utils.h"
46 #include "parser.h"
47 #include "result.h"
48 #include "service.h"
49 #include "service_list.h"
50 #include "service_parser.h"
51 
52 using namespace std::literals;
53 
54 using android::base::ParseInt;
55 using android::base::ReadFileToString;
56 using android::base::Split;
57 using android::properties::BuildTrie;
58 using android::properties::ParsePropertyInfoFile;
59 using android::properties::PropertyInfoArea;
60 using android::properties::PropertyInfoEntry;
61 
62 static std::vector<std::string> passwd_files;
63 
GetVendorPasswd(const std::string & passwd_file)64 static std::vector<std::pair<std::string, int>> GetVendorPasswd(const std::string& passwd_file) {
65     std::string passwd;
66     if (!ReadFileToString(passwd_file, &passwd)) {
67         return {};
68     }
69 
70     std::vector<std::pair<std::string, int>> result;
71     auto passwd_lines = Split(passwd, "\n");
72     for (const auto& line : passwd_lines) {
73         auto split_line = Split(line, ":");
74         if (split_line.size() < 3) {
75             continue;
76         }
77         int uid = 0;
78         if (!ParseInt(split_line[2], &uid)) {
79             continue;
80         }
81         result.emplace_back(split_line[0], uid);
82     }
83     return result;
84 }
85 
GetVendorPasswd()86 static std::vector<std::pair<std::string, int>> GetVendorPasswd() {
87     std::vector<std::pair<std::string, int>> result;
88     for (const auto& passwd_file : passwd_files) {
89         auto individual_result = GetVendorPasswd(passwd_file);
90         std::move(individual_result.begin(), individual_result.end(),
91                   std::back_insert_iterator(result));
92     }
93     return result;
94 }
95 
getpwnam(const char * login)96 passwd* getpwnam(const char* login) {  // NOLINT: implementing bad function.
97     // This isn't thread safe, but that's okay for our purposes.
98     static char static_name[32] = "";
99     static char static_dir[32] = "/";
100     static char static_shell[32] = "/system/bin/sh";
101     static passwd static_passwd = {
102         .pw_name = static_name,
103         .pw_dir = static_dir,
104         .pw_shell = static_shell,
105         .pw_uid = 0,
106         .pw_gid = 0,
107     };
108 
109     for (size_t n = 0; n < android_id_count; ++n) {
110         if (!strcmp(android_ids[n].name, login)) {
111             snprintf(static_name, sizeof(static_name), "%s", android_ids[n].name);
112             static_passwd.pw_uid = android_ids[n].aid;
113             static_passwd.pw_gid = android_ids[n].aid;
114             return &static_passwd;
115         }
116     }
117 
118     static const auto vendor_passwd = GetVendorPasswd();
119 
120     for (const auto& [name, uid] : vendor_passwd) {
121         if (name == login) {
122             snprintf(static_name, sizeof(static_name), "%s", name.c_str());
123             static_passwd.pw_uid = uid;
124             static_passwd.pw_gid = uid;
125             return &static_passwd;
126         }
127     }
128 
129     unsigned int oem_uid;
130     if (sscanf(login, "oem_%u", &oem_uid) == 1) {
131         snprintf(static_name, sizeof(static_name), "%s", login);
132         static_passwd.pw_uid = oem_uid;
133         static_passwd.pw_gid = oem_uid;
134         return &static_passwd;
135     }
136 
137     errno = ENOENT;
138     return nullptr;
139 }
140 
141 namespace android {
142 namespace init {
143 
check_stub(const BuiltinArguments & args)144 static Result<void> check_stub(const BuiltinArguments& args) {
145     return {};
146 }
147 
148 #include "generated_stub_builtin_function_map.h"
149 
PrintUsage()150 void PrintUsage() {
151     std::cout << "usage: host_init_verifier [options] <init rc file>\n"
152                  "\n"
153                  "Tests an init script for correctness\n"
154                  "\n"
155                  "-p FILE\tSearch this passwd file for users and groups\n"
156                  "--property_contexts=FILE\t Use this file for property_contexts\n"
157               << std::endl;
158 }
159 
ReadInterfaceInheritanceHierarchy()160 Result<InterfaceInheritanceHierarchyMap> ReadInterfaceInheritanceHierarchy() {
161     InterfaceInheritanceHierarchyMap result;
162     for (const HidlInterfaceMetadata& iface : HidlInterfaceMetadata::all()) {
163         std::set<FQName> inherited_interfaces;
164         for (const std::string& intf : iface.inherited) {
165             FQName fqname;
166             if (!fqname.setTo(intf)) {
167                 return Error() << "Unable to parse interface '" << intf << "'";
168             }
169             inherited_interfaces.insert(fqname);
170         }
171         FQName fqname;
172         if (!fqname.setTo(iface.name)) {
173             return Error() << "Unable to parse interface '" << iface.name << "'";
174         }
175         result[fqname] = inherited_interfaces;
176     }
177 
178     return result;
179 }
180 
181 const PropertyInfoArea* property_info_area;
182 
HandlePropertyContexts(const std::string & filename,std::vector<PropertyInfoEntry> * property_infos)183 void HandlePropertyContexts(const std::string& filename,
184                             std::vector<PropertyInfoEntry>* property_infos) {
185     auto file_contents = std::string();
186     if (!ReadFileToString(filename, &file_contents)) {
187         PLOG(ERROR) << "Could not read properties from '" << filename << "'";
188         exit(EXIT_FAILURE);
189     }
190 
191     auto errors = std::vector<std::string>{};
192     ParsePropertyInfoFile(file_contents, true, property_infos, &errors);
193     for (const auto& error : errors) {
194         LOG(ERROR) << "Could not read line from '" << filename << "': " << error;
195     }
196     if (!errors.empty()) {
197         exit(EXIT_FAILURE);
198     }
199 }
200 
main(int argc,char ** argv)201 int main(int argc, char** argv) {
202     android::base::InitLogging(argv, &android::base::StdioLogger);
203     android::base::SetMinimumLogSeverity(android::base::ERROR);
204 
205     auto property_infos = std::vector<PropertyInfoEntry>();
206 
207     while (true) {
208         static const char kPropertyContexts[] = "property-contexts=";
209         static const struct option long_options[] = {
210                 {"help", no_argument, nullptr, 'h'},
211                 {kPropertyContexts, required_argument, nullptr, 0},
212                 {nullptr, 0, nullptr, 0},
213         };
214 
215         int option_index;
216         int arg = getopt_long(argc, argv, "p:", long_options, &option_index);
217 
218         if (arg == -1) {
219             break;
220         }
221 
222         switch (arg) {
223             case 0:
224                 if (long_options[option_index].name == kPropertyContexts) {
225                     HandlePropertyContexts(optarg, &property_infos);
226                 }
227                 break;
228             case 'h':
229                 PrintUsage();
230                 return EXIT_FAILURE;
231             case 'p':
232                 passwd_files.emplace_back(optarg);
233                 break;
234             default:
235                 std::cerr << "getprop: getopt returned invalid result: " << arg << std::endl;
236                 return EXIT_FAILURE;
237         }
238     }
239 
240     argc -= optind;
241     argv += optind;
242 
243     if (argc != 1) {
244         PrintUsage();
245         return EXIT_FAILURE;
246     }
247 
248     auto interface_inheritance_hierarchy_map = ReadInterfaceInheritanceHierarchy();
249     if (!interface_inheritance_hierarchy_map.ok()) {
250         LOG(ERROR) << interface_inheritance_hierarchy_map.error();
251         return EXIT_FAILURE;
252     }
253     SetKnownInterfaces(*interface_inheritance_hierarchy_map);
254 
255     std::string serialized_contexts;
256     std::string trie_error;
257     if (!BuildTrie(property_infos, "u:object_r:default_prop:s0", "string", &serialized_contexts,
258                    &trie_error)) {
259         LOG(ERROR) << "Unable to serialize property contexts: " << trie_error;
260         return EXIT_FAILURE;
261     }
262 
263     property_info_area = reinterpret_cast<const PropertyInfoArea*>(serialized_contexts.c_str());
264 
265     const BuiltinFunctionMap& function_map = GetBuiltinFunctionMap();
266     Action::set_function_map(&function_map);
267     ActionManager& am = ActionManager::GetInstance();
268     ServiceList& sl = ServiceList::GetInstance();
269     Parser parser;
270     parser.AddSectionParser("service", std::make_unique<ServiceParser>(
271                                                &sl, nullptr, *interface_inheritance_hierarchy_map));
272     parser.AddSectionParser("on", std::make_unique<ActionParser>(&am, nullptr));
273     parser.AddSectionParser("import", std::make_unique<HostImportParser>());
274 
275     if (!parser.ParseConfigFileInsecure(*argv)) {
276         LOG(ERROR) << "Failed to open init rc script '" << *argv << "'";
277         return EXIT_FAILURE;
278     }
279     size_t failures = parser.parse_error_count() + am.CheckAllCommands() + sl.CheckAllCommands();
280     if (failures > 0) {
281         LOG(ERROR) << "Failed to parse init script '" << *argv << "' with " << failures
282                    << " errors";
283         return EXIT_FAILURE;
284     }
285     return EXIT_SUCCESS;
286 }
287 
288 }  // namespace init
289 }  // namespace android
290 
main(int argc,char ** argv)291 int main(int argc, char** argv) {
292     return android::init::main(argc, argv);
293 }
294