1 /*
2  * Copyright (C) 2016 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 #include <errno.h>
17 #include <getopt.h>
18 #include <stdbool.h>
19 #include <stdint.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <sys/capability.h>
23 #include <sys/prctl.h>
24 #include <sys/stat.h>
25 #include <unistd.h>
26 
27 #include <android/binder_process.h>
28 #include <cutils/android_filesystem_config.h>
29 
30 #include "checkpoint_handling.h"
31 #include "ipc.h"
32 #include "log.h"
33 #include "rpmb.h"
34 #include "storage.h"
35 #include "watchdog.h"
36 
37 #define REQ_BUFFER_SIZE 4096
38 static uint8_t req_buffer[REQ_BUFFER_SIZE + 1];
39 
40 static const char* ss_data_root;
41 static const char* trusty_devname;
42 static const char* rpmb_devname;
43 static const char* ss_srv_name = STORAGE_DISK_PROXY_PORT;
44 static const char* max_file_size_from;
45 
46 static enum dev_type dev_type = MMC_RPMB;
47 
48 /* List head for storage mapping, elements added at init, and never removed */
49 static struct storage_mapping_node* storage_mapping_head;
50 
parse_dev_type(const char * dev_type_name)51 static enum dev_type parse_dev_type(const char* dev_type_name) {
52     if (!strcmp(dev_type_name, "mmc")) {
53         return MMC_RPMB;
54     } else if (!strcmp(dev_type_name, "virt")) {
55         return VIRT_RPMB;
56     } else if (!strcmp(dev_type_name, "sock")) {
57         return SOCK_RPMB;
58     } else if (!strcmp(dev_type_name, "ufs")) {
59         return UFS_RPMB;
60     } else {
61         return UNKNOWN_RPMB;
62     }
63 }
64 
parse_and_append_file_mapping(const char * file_mapping)65 static int parse_and_append_file_mapping(const char* file_mapping) {
66     if (file_mapping == NULL) {
67         ALOGE("Provided file mapping is null\n");
68         return -1;
69     }
70     char* file_mapping_dup = strdup(file_mapping);
71     if (file_mapping_dup == NULL) {
72         ALOGE("Couldn't duplicate string: %s\n", file_mapping);
73         return -1;
74     }
75     const char* file_name = strtok(file_mapping_dup, ":");
76     if (file_name == NULL) {
77         ALOGE("No file name found\n");
78         return -1;
79     }
80     const char* backing_storage = strtok(NULL, ":");
81     if (backing_storage == NULL) {
82         ALOGE("No backing storage found\n");
83         return -1;
84     }
85 
86     struct storage_mapping_node* new_node = malloc(sizeof(struct storage_mapping_node));
87     if (new_node == NULL) {
88         ALOGE("Couldn't allocate additional storage_mapping_node\n");
89         return -1;
90     }
91     *new_node = (struct storage_mapping_node){.file_name = file_name,
92                                               .backing_storage = backing_storage,
93                                               .next = storage_mapping_head,
94                                               .fd = -1};
95     storage_mapping_head = new_node;
96     return 0;
97 }
98 
99 static const char* _sopts = "hp:d:r:t:m:f:";
100 static const struct option _lopts[] = {{"help", no_argument, NULL, 'h'},
101                                        {"trusty_dev", required_argument, NULL, 'd'},
102                                        {"data_path", required_argument, NULL, 'p'},
103                                        {"rpmb_dev", required_argument, NULL, 'r'},
104                                        {"dev_type", required_argument, NULL, 't'},
105                                        {"max_file_size_from", required_argument, NULL, 'm'},
106                                        {"file_storage_mapping", required_argument, NULL, 'f'},
107                                        {0, 0, 0, 0}};
108 
show_usage_and_exit(int code)109 static void show_usage_and_exit(int code) {
110     ALOGE("usage: storageproxyd -d <trusty_dev> -p <data_path> -r <rpmb_dev> -t <dev_type>  [-m "
111           "<file>] [-f <file>:<mapping>]\n");
112     ALOGE("Available dev types: mmc, virt\n");
113     ALOGE("-f = Maps secure storage files like `0` and `persist/0`\n"
114           "to block devices.  Storageproxyd will handle creating the\n"
115           "appropriate symlinks in the root datapath.\n");
116     ALOGE("-m = Specifies the max size constraint for file backed storages.\n"
117           "The constraint is chosen by giving a file, this allows for passing a\n"
118           "block device for which a max file size can be queried.  File based\n"
119           "storages will be constrained to that size as well.\n");
120     exit(code);
121 }
122 
handle_req(struct storage_msg * msg,const void * req,size_t req_len)123 static int handle_req(struct storage_msg* msg, const void* req, size_t req_len) {
124     int rc;
125 
126     struct watcher* watcher = watch_start("request", msg);
127 
128     if ((msg->flags & STORAGE_MSG_FLAG_POST_COMMIT) && msg->cmd != STORAGE_RPMB_SEND &&
129         msg->cmd != STORAGE_FILE_WRITE) {
130         /*
131          * handling post commit messages on commands other than rpmb and write
132          * operations are not implemented as there is no use case for this yet.
133          */
134         ALOGE("cmd 0x%x: post commit option is not implemented\n", msg->cmd);
135         msg->result = STORAGE_ERR_UNIMPLEMENTED;
136         goto err_response;
137     }
138 
139     if (msg->flags & STORAGE_MSG_FLAG_PRE_COMMIT) {
140         rc = storage_sync_checkpoint(watcher);
141         if (rc < 0) {
142             msg->result = STORAGE_ERR_SYNC_FAILURE;
143             goto err_response;
144         }
145     }
146 
147     if (msg->flags & STORAGE_MSG_FLAG_PRE_COMMIT_CHECKPOINT) {
148         bool is_checkpoint_active = false;
149 
150         rc = is_data_checkpoint_active(&is_checkpoint_active);
151         if (rc != 0) {
152             ALOGE("is_data_checkpoint_active failed in an unexpected way. Aborting.\n");
153             msg->result = STORAGE_ERR_GENERIC;
154             goto err_response;
155         } else if (is_checkpoint_active) {
156             ALOGE("Checkpoint in progress, dropping write ...\n");
157             msg->result = STORAGE_ERR_GENERIC;
158             goto err_response;
159         }
160     }
161 
162     switch (msg->cmd) {
163         case STORAGE_FILE_DELETE:
164             rc = storage_file_delete(msg, req, req_len, watcher);
165             break;
166 
167         case STORAGE_FILE_OPEN:
168             rc = storage_file_open(msg, req, req_len, watcher);
169             break;
170 
171         case STORAGE_FILE_CLOSE:
172             rc = storage_file_close(msg, req, req_len, watcher);
173             break;
174 
175         case STORAGE_FILE_WRITE:
176             rc = storage_file_write(msg, req, req_len, watcher);
177             break;
178 
179         case STORAGE_FILE_READ:
180             rc = storage_file_read(msg, req, req_len, watcher);
181             break;
182 
183         case STORAGE_FILE_GET_SIZE:
184             rc = storage_file_get_size(msg, req, req_len, watcher);
185             break;
186 
187         case STORAGE_FILE_SET_SIZE:
188             rc = storage_file_set_size(msg, req, req_len, watcher);
189             break;
190 
191         case STORAGE_FILE_GET_MAX_SIZE:
192             rc = storage_file_get_max_size(msg, req, req_len, watcher);
193             break;
194 
195         case STORAGE_RPMB_SEND:
196             rc = rpmb_send(msg, req, req_len, watcher);
197             break;
198 
199         default:
200             ALOGE("unhandled command 0x%x\n", msg->cmd);
201             msg->result = STORAGE_ERR_UNIMPLEMENTED;
202             goto err_response;
203     }
204 
205     /* response was sent in handler */
206     goto finish;
207 
208 err_response:
209     rc = ipc_respond(msg, NULL, 0);
210 
211 finish:
212     watch_finish(watcher);
213     return rc;
214 }
215 
proxy_loop(void)216 static int proxy_loop(void) {
217     ssize_t rc;
218     struct storage_msg msg;
219 
220     /* enter main message handling loop */
221     while (true) {
222         /* get incoming message */
223         rc = ipc_get_msg(&msg, req_buffer, REQ_BUFFER_SIZE);
224         if (rc < 0) return rc;
225 
226         /* handle request */
227         req_buffer[rc] = 0; /* force zero termination */
228         rc = handle_req(&msg, req_buffer, rc);
229         if (rc) return rc;
230     }
231 
232     return 0;
233 }
234 
parse_args(int argc,char * argv[])235 static void parse_args(int argc, char* argv[]) {
236     int opt;
237     int oidx = 0;
238     int rc = 0;
239 
240     while ((opt = getopt_long(argc, argv, _sopts, _lopts, &oidx)) != -1) {
241         switch (opt) {
242             case 'd':
243                 trusty_devname = strdup(optarg);
244                 break;
245 
246             case 'p':
247                 ss_data_root = strdup(optarg);
248                 break;
249 
250             case 'r':
251                 rpmb_devname = strdup(optarg);
252                 break;
253 
254             case 't':
255                 dev_type = parse_dev_type(optarg);
256                 if (dev_type == UNKNOWN_RPMB) {
257                     ALOGE("Unrecognized dev type: %s\n", optarg);
258                     show_usage_and_exit(EXIT_FAILURE);
259                 }
260                 break;
261 
262             case 'f':
263                 rc = parse_and_append_file_mapping(optarg);
264                 if (rc < 0) {
265                     ALOGE("Failed to parse file mapping: %s\n", optarg);
266                     show_usage_and_exit(EXIT_FAILURE);
267                 }
268                 break;
269 
270             case 'm':
271                 max_file_size_from = strdup(optarg);
272                 break;
273 
274             default:
275                 ALOGE("unrecognized option (%c):\n", opt);
276                 show_usage_and_exit(EXIT_FAILURE);
277         }
278     }
279 
280     if (ss_data_root == NULL || trusty_devname == NULL || rpmb_devname == NULL) {
281         ALOGE("missing required argument(s)\n");
282         show_usage_and_exit(EXIT_FAILURE);
283     }
284 
285     ALOGI("starting storageproxyd\n");
286     ALOGI("storage data root: %s\n", ss_data_root);
287     ALOGI("trusty dev: %s\n", trusty_devname);
288     ALOGI("rpmb dev: %s\n", rpmb_devname);
289     ALOGI("File Mappings: \n");
290     const struct storage_mapping_node* curr = storage_mapping_head;
291     for (; curr != NULL; curr = curr->next) {
292         ALOGI("\t%s -> %s\n", curr->file_name, curr->backing_storage);
293     }
294     ALOGI("max file size from: %s\n", max_file_size_from ? max_file_size_from : "(unset)");
295 }
296 
main(int argc,char * argv[])297 int main(int argc, char* argv[]) {
298     int rc;
299 
300     /*
301      * No access for group and other. We need execute access for user to create
302      * an accessible directory.
303      */
304     umask(S_IRWXG | S_IRWXO);
305 
306     /* parse arguments */
307     parse_args(argc, argv);
308 
309     /*
310      * Start binder threadpool. At least one extra binder thread is needed to
311      * connect to the wakelock service without relying on polling. If we poll on
312      * the main thread we end up pausing for at least 1s even if the service
313      * starts faster. We set the max thread count to 0 because startThreadPool
314      * "Starts one thread, PLUS those requested in setThreadPoolMaxThreadCount,
315      * PLUS those manually requested in joinThreadPool." We only need a single
316      * binder thread to receive notifications on.
317      */
318     ABinderProcess_setThreadPoolMaxThreadCount(0);
319     ABinderProcess_startThreadPool();
320 
321     /* initialize secure storage directory */
322     rc = storage_init(ss_data_root, storage_mapping_head, max_file_size_from);
323     if (rc < 0) return EXIT_FAILURE;
324 
325     /* open rpmb device */
326     rc = rpmb_open(rpmb_devname, dev_type);
327     if (rc < 0) return EXIT_FAILURE;
328 
329     /* connect to Trusty secure storage server */
330     rc = ipc_connect(trusty_devname, ss_srv_name);
331     if (rc < 0) return EXIT_FAILURE;
332 
333     /* enter main loop */
334     rc = proxy_loop();
335     ALOGE("exiting proxy loop with status (%d)\n", rc);
336 
337     ipc_disconnect();
338     rpmb_close();
339 
340     return (rc < 0) ? EXIT_FAILURE : EXIT_SUCCESS;
341 }
342