Michael Ryleev | 7a2bc37 | 2016-03-08 15:16:11 -0800 | [diff] [blame] | 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 <string.h> |
| 21 | #include <stdlib.h> |
| 22 | #include <sys/capability.h> |
| 23 | #include <sys/prctl.h> |
| 24 | #include <sys/stat.h> |
| 25 | #include <unistd.h> |
| 26 | |
| 27 | #include <private/android_filesystem_config.h> |
| 28 | |
| 29 | #include "ipc.h" |
| 30 | #include "log.h" |
| 31 | #include "rpmb.h" |
| 32 | #include "storage.h" |
| 33 | |
| 34 | #define REQ_BUFFER_SIZE 4096 |
| 35 | static uint8_t req_buffer[REQ_BUFFER_SIZE + 1]; |
| 36 | |
| 37 | static const char *ss_data_root; |
| 38 | static const char *trusty_devname; |
| 39 | static const char *rpmb_devname; |
| 40 | static const char *ss_srv_name = STORAGE_DISK_PROXY_PORT; |
| 41 | |
| 42 | static const char *_sopts = "hp:d:r:"; |
| 43 | static const struct option _lopts[] = { |
| 44 | {"help", no_argument, NULL, 'h'}, |
| 45 | {"trusty_dev", required_argument, NULL, 'd'}, |
| 46 | {"data_path", required_argument, NULL, 'p'}, |
| 47 | {"rpmb_dev", required_argument, NULL, 'r'}, |
| 48 | {0, 0, 0, 0} |
| 49 | }; |
| 50 | |
| 51 | static void show_usage_and_exit(int code) |
| 52 | { |
| 53 | ALOGE("usage: storageproxyd -d <trusty_dev> -p <data_path> -r <rpmb_dev>\n"); |
| 54 | exit(code); |
| 55 | } |
| 56 | |
| 57 | static int drop_privs(void) |
| 58 | { |
| 59 | struct __user_cap_header_struct capheader; |
| 60 | struct __user_cap_data_struct capdata[2]; |
| 61 | |
| 62 | if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) < 0) { |
| 63 | return -1; |
| 64 | } |
| 65 | |
| 66 | /* |
| 67 | * ensure we're running as the system user |
| 68 | */ |
| 69 | if (setgid(AID_SYSTEM) != 0) { |
| 70 | return -1; |
| 71 | } |
| 72 | |
| 73 | if (setuid(AID_SYSTEM) != 0) { |
| 74 | return -1; |
| 75 | } |
| 76 | |
| 77 | /* |
| 78 | * drop all capabilities except SYS_RAWIO |
| 79 | */ |
| 80 | memset(&capheader, 0, sizeof(capheader)); |
| 81 | memset(&capdata, 0, sizeof(capdata)); |
| 82 | capheader.version = _LINUX_CAPABILITY_VERSION_3; |
| 83 | capheader.pid = 0; |
| 84 | |
| 85 | capdata[CAP_TO_INDEX(CAP_SYS_RAWIO)].permitted = CAP_TO_MASK(CAP_SYS_RAWIO); |
| 86 | capdata[CAP_TO_INDEX(CAP_SYS_RAWIO)].effective = CAP_TO_MASK(CAP_SYS_RAWIO); |
| 87 | |
| 88 | if (capset(&capheader, &capdata[0]) < 0) { |
| 89 | return -1; |
| 90 | } |
| 91 | |
| 92 | /* no-execute for user, no access for group and other */ |
| 93 | umask(S_IXUSR | S_IRWXG | S_IRWXO); |
| 94 | |
| 95 | return 0; |
| 96 | } |
| 97 | |
| 98 | static int handle_req(struct storage_msg *msg, const void *req, size_t req_len) |
| 99 | { |
| 100 | int rc; |
| 101 | |
| 102 | if ((msg->flags & STORAGE_MSG_FLAG_POST_COMMIT) && |
| 103 | (msg->cmd != STORAGE_RPMB_SEND)) { |
| 104 | /* |
| 105 | * handling post commit messages on non rpmb commands are not |
| 106 | * implemented as there is no use case for this yet. |
| 107 | */ |
| 108 | ALOGE("cmd 0x%x: post commit option is not implemented\n", msg->cmd); |
| 109 | msg->result = STORAGE_ERR_UNIMPLEMENTED; |
| 110 | return ipc_respond(msg, NULL, 0); |
| 111 | } |
| 112 | |
| 113 | if (msg->flags & STORAGE_MSG_FLAG_PRE_COMMIT) { |
| 114 | rc = storage_sync_checkpoint(); |
| 115 | if (rc < 0) { |
| 116 | msg->result = STORAGE_ERR_GENERIC; |
| 117 | return ipc_respond(msg, NULL, 0); |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | switch (msg->cmd) { |
| 122 | case STORAGE_FILE_DELETE: |
| 123 | rc = storage_file_delete(msg, req, req_len); |
| 124 | break; |
| 125 | |
| 126 | case STORAGE_FILE_OPEN: |
| 127 | rc = storage_file_open(msg, req, req_len); |
| 128 | break; |
| 129 | |
| 130 | case STORAGE_FILE_CLOSE: |
| 131 | rc = storage_file_close(msg, req, req_len); |
| 132 | break; |
| 133 | |
| 134 | case STORAGE_FILE_WRITE: |
| 135 | rc = storage_file_write(msg, req, req_len); |
| 136 | break; |
| 137 | |
| 138 | case STORAGE_FILE_READ: |
| 139 | rc = storage_file_read(msg, req, req_len); |
| 140 | break; |
| 141 | |
| 142 | case STORAGE_FILE_GET_SIZE: |
| 143 | rc = storage_file_get_size(msg, req, req_len); |
| 144 | break; |
| 145 | |
| 146 | case STORAGE_FILE_SET_SIZE: |
| 147 | rc = storage_file_set_size(msg, req, req_len); |
| 148 | break; |
| 149 | |
| 150 | case STORAGE_RPMB_SEND: |
| 151 | rc = rpmb_send(msg, req, req_len); |
| 152 | break; |
| 153 | |
| 154 | default: |
| 155 | ALOGE("unhandled command 0x%x\n", msg->cmd); |
| 156 | msg->result = STORAGE_ERR_UNIMPLEMENTED; |
| 157 | rc = 1; |
| 158 | } |
| 159 | |
| 160 | if (rc > 0) { |
| 161 | /* still need to send response */ |
| 162 | rc = ipc_respond(msg, NULL, 0); |
| 163 | } |
| 164 | return rc; |
| 165 | } |
| 166 | |
| 167 | static int proxy_loop(void) |
| 168 | { |
| 169 | ssize_t rc; |
| 170 | struct storage_msg msg; |
| 171 | |
| 172 | /* enter main message handling loop */ |
| 173 | while (true) { |
| 174 | |
| 175 | /* get incoming message */ |
| 176 | rc = ipc_get_msg(&msg, req_buffer, REQ_BUFFER_SIZE); |
| 177 | if (rc < 0) |
| 178 | return rc; |
| 179 | |
| 180 | /* handle request */ |
| 181 | req_buffer[rc] = 0; /* force zero termination */ |
| 182 | rc = handle_req(&msg, req_buffer, rc); |
| 183 | if (rc) |
| 184 | return rc; |
| 185 | } |
| 186 | |
| 187 | return 0; |
| 188 | } |
| 189 | |
| 190 | static void parse_args(int argc, char *argv[]) |
| 191 | { |
| 192 | int opt; |
| 193 | int oidx = 0; |
| 194 | |
| 195 | while ((opt = getopt_long(argc, argv, _sopts, _lopts, &oidx)) != -1) { |
| 196 | switch (opt) { |
| 197 | |
| 198 | case 'd': |
| 199 | trusty_devname = strdup(optarg); |
| 200 | break; |
| 201 | |
| 202 | case 'p': |
| 203 | ss_data_root = strdup(optarg); |
| 204 | break; |
| 205 | |
| 206 | case 'r': |
| 207 | rpmb_devname = strdup(optarg); |
| 208 | break; |
| 209 | |
| 210 | default: |
| 211 | ALOGE("unrecognized option (%c):\n", opt); |
| 212 | show_usage_and_exit(EXIT_FAILURE); |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | if (ss_data_root == NULL || |
| 217 | trusty_devname == NULL || |
| 218 | rpmb_devname == NULL) { |
| 219 | ALOGE("missing required argument(s)\n"); |
| 220 | show_usage_and_exit(EXIT_FAILURE); |
| 221 | } |
| 222 | |
| 223 | ALOGI("starting storageproxyd\n"); |
| 224 | ALOGI("storage data root: %s\n", ss_data_root); |
| 225 | ALOGI("trusty dev: %s\n", trusty_devname); |
| 226 | ALOGI("rpmb dev: %s\n", rpmb_devname); |
| 227 | } |
| 228 | |
| 229 | int main(int argc, char *argv[]) |
| 230 | { |
| 231 | int rc; |
| 232 | uint retry_cnt; |
| 233 | |
| 234 | /* drop privileges */ |
| 235 | if (drop_privs() < 0) |
| 236 | return EXIT_FAILURE; |
| 237 | |
| 238 | /* parse arguments */ |
| 239 | parse_args(argc, argv); |
| 240 | |
| 241 | /* initialize secure storage directory */ |
| 242 | rc = storage_init(ss_data_root); |
| 243 | if (rc < 0) |
| 244 | return EXIT_FAILURE; |
| 245 | |
| 246 | /* open rpmb device */ |
| 247 | rc = rpmb_open(rpmb_devname); |
| 248 | if (rc < 0) |
| 249 | return EXIT_FAILURE; |
| 250 | |
| 251 | /* connect to Trusty secure storage server */ |
| 252 | rc = ipc_connect(trusty_devname, ss_srv_name); |
| 253 | if (rc < 0) |
| 254 | return EXIT_FAILURE; |
| 255 | |
| 256 | /* enter main loop */ |
| 257 | rc = proxy_loop(); |
| 258 | ALOGE("exiting proxy loop with status (%d)\n", rc); |
| 259 | |
| 260 | ipc_disconnect(); |
| 261 | rpmb_close(); |
| 262 | |
| 263 | return (rc < 0) ? EXIT_FAILURE : EXIT_SUCCESS; |
| 264 | } |