David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 1 | /* |
David Zeuthen | 86fd178 | 2017-03-28 15:37:55 -0400 | [diff] [blame] | 2 | * Copyright (C) 2017 The Android Open Source Project |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 3 | * |
| 4 | * Permission is hereby granted, free of charge, to any person |
| 5 | * obtaining a copy of this software and associated documentation |
| 6 | * files (the "Software"), to deal in the Software without |
| 7 | * restriction, including without limitation the rights to use, copy, |
| 8 | * modify, merge, publish, distribute, sublicense, and/or sell copies |
| 9 | * of the Software, and to permit persons to whom the Software is |
| 10 | * furnished to do so, subject to the following conditions: |
| 11 | * |
| 12 | * The above copyright notice and this permission notice shall be |
| 13 | * included in all copies or substantial portions of the Software. |
| 14 | * |
| 15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 16 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 17 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| 18 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS |
| 19 | * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN |
| 20 | * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
| 21 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| 22 | * SOFTWARE. |
| 23 | */ |
| 24 | |
David Zeuthen | 86fd178 | 2017-03-28 15:37:55 -0400 | [diff] [blame] | 25 | #include "avb_ops_user.h" |
| 26 | |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 27 | #include <errno.h> |
| 28 | #include <fcntl.h> |
| 29 | #include <linux/fs.h> |
| 30 | #include <stdlib.h> |
| 31 | #include <string.h> |
| 32 | #include <sys/ioctl.h> |
| 33 | #include <sys/stat.h> |
| 34 | #include <sys/types.h> |
| 35 | #include <unistd.h> |
| 36 | |
| 37 | #include <cutils/properties.h> |
| 38 | #include <fs_mgr.h> |
| 39 | |
David Zeuthen | 86fd178 | 2017-03-28 15:37:55 -0400 | [diff] [blame] | 40 | #include <libavb_ab/libavb_ab.h> |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 41 | |
| 42 | /* Open the appropriate fstab file and fallback to /fstab.device if |
| 43 | * that's what's being used. |
| 44 | */ |
| 45 | static struct fstab* open_fstab(void) { |
Bowgo Tsai | 49a88a3 | 2017-03-10 18:59:15 +0800 | [diff] [blame] | 46 | struct fstab* fstab = fs_mgr_read_fstab_default(); |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 47 | |
David Zeuthen | 4b6a634 | 2017-01-03 15:19:56 -0500 | [diff] [blame] | 48 | if (fstab != NULL) { |
| 49 | return fstab; |
| 50 | } |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 51 | |
David Zeuthen | 86fd178 | 2017-03-28 15:37:55 -0400 | [diff] [blame] | 52 | fstab = fs_mgr_read_fstab("/fstab.device"); |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 53 | return fstab; |
| 54 | } |
| 55 | |
| 56 | static int open_partition(const char* name, int flags) { |
| 57 | char* path; |
| 58 | int fd; |
| 59 | struct fstab* fstab; |
| 60 | struct fstab_rec* record; |
| 61 | |
| 62 | /* We can't use fs_mgr to look up |name| because fstab doesn't list |
| 63 | * every slot partition (it uses the slotselect option to mask the |
| 64 | * suffix) and |slot| is expected to be of that form, e.g. boot_a. |
| 65 | * |
| 66 | * We can however assume that there's an entry for the /misc mount |
| 67 | * point and use that to get the device file for the misc |
| 68 | * partition. From there we'll assume that a by-name scheme is used |
| 69 | * so we can just replace the trailing "misc" by the given |name|, |
| 70 | * e.g. |
| 71 | * |
| 72 | * /dev/block/platform/soc.0/7824900.sdhci/by-name/misc -> |
| 73 | * /dev/block/platform/soc.0/7824900.sdhci/by-name/boot_a |
| 74 | * |
| 75 | * If needed, it's possible to relax this assumption in the future |
| 76 | * by trawling /sys/block looking for the appropriate sibling of |
| 77 | * misc and then finding an entry in /dev matching the sysfs entry. |
| 78 | */ |
| 79 | |
| 80 | fstab = open_fstab(); |
| 81 | if (fstab == NULL) { |
| 82 | return -1; |
| 83 | } |
| 84 | record = fs_mgr_get_entry_for_mount_point(fstab, "/misc"); |
| 85 | if (record == NULL) { |
| 86 | fs_mgr_free_fstab(fstab); |
| 87 | return -1; |
| 88 | } |
| 89 | if (strcmp(name, "misc") == 0) { |
| 90 | path = strdup(record->blk_device); |
| 91 | } else { |
| 92 | size_t trimmed_len, name_len; |
| 93 | const char* end_slash = strrchr(record->blk_device, '/'); |
| 94 | if (end_slash == NULL) { |
| 95 | fs_mgr_free_fstab(fstab); |
| 96 | return -1; |
| 97 | } |
| 98 | trimmed_len = end_slash - record->blk_device + 1; |
| 99 | name_len = strlen(name); |
| 100 | path = calloc(trimmed_len + name_len + 1, 1); |
| 101 | strncpy(path, record->blk_device, trimmed_len); |
| 102 | strncpy(path + trimmed_len, name, name_len); |
| 103 | } |
| 104 | fs_mgr_free_fstab(fstab); |
| 105 | |
| 106 | fd = open(path, flags); |
| 107 | free(path); |
| 108 | |
| 109 | return fd; |
| 110 | } |
| 111 | |
David Zeuthen | 4b6a634 | 2017-01-03 15:19:56 -0500 | [diff] [blame] | 112 | static AvbIOResult read_from_partition(AvbOps* ops, |
| 113 | const char* partition, |
| 114 | int64_t offset, |
| 115 | size_t num_bytes, |
| 116 | void* buffer, |
| 117 | size_t* out_num_read) { |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 118 | int fd; |
| 119 | off_t where; |
| 120 | ssize_t num_read; |
| 121 | AvbIOResult ret; |
| 122 | |
| 123 | fd = open_partition(partition, O_RDONLY); |
| 124 | if (fd == -1) { |
David Zeuthen | 86fd178 | 2017-03-28 15:37:55 -0400 | [diff] [blame] | 125 | ret = AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION; |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 126 | goto out; |
| 127 | } |
| 128 | |
David Zeuthen | 86fd178 | 2017-03-28 15:37:55 -0400 | [diff] [blame] | 129 | if (offset < 0) { |
| 130 | uint64_t partition_size; |
| 131 | if (ioctl(fd, BLKGETSIZE64, &partition_size) != 0) { |
| 132 | avb_errorv( |
| 133 | "Error getting size of \"", partition, "\" partition.\n", NULL); |
| 134 | ret = AVB_IO_RESULT_ERROR_IO; |
| 135 | goto out; |
| 136 | } |
| 137 | offset = partition_size - (-offset); |
| 138 | } |
| 139 | |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 140 | where = lseek(fd, offset, SEEK_SET); |
| 141 | if (where == -1) { |
| 142 | avb_error("Error seeking to offset.\n"); |
| 143 | ret = AVB_IO_RESULT_ERROR_IO; |
| 144 | goto out; |
| 145 | } |
| 146 | if (where != offset) { |
| 147 | avb_error("Error seeking to offset.\n"); |
| 148 | ret = AVB_IO_RESULT_ERROR_RANGE_OUTSIDE_PARTITION; |
| 149 | goto out; |
| 150 | } |
| 151 | |
| 152 | /* On Linux, we never get partial reads from block devices (except |
| 153 | * for EOF). |
| 154 | */ |
| 155 | num_read = read(fd, buffer, num_bytes); |
| 156 | if (num_read == -1) { |
| 157 | avb_error("Error reading data.\n"); |
| 158 | ret = AVB_IO_RESULT_ERROR_IO; |
| 159 | goto out; |
| 160 | } |
| 161 | if (out_num_read != NULL) { |
| 162 | *out_num_read = num_read; |
| 163 | } |
| 164 | |
| 165 | ret = AVB_IO_RESULT_OK; |
| 166 | |
| 167 | out: |
| 168 | if (fd != -1) { |
| 169 | if (close(fd) != 0) { |
| 170 | avb_error("Error closing file descriptor.\n"); |
| 171 | } |
| 172 | } |
| 173 | return ret; |
| 174 | } |
| 175 | |
David Zeuthen | 4b6a634 | 2017-01-03 15:19:56 -0500 | [diff] [blame] | 176 | static AvbIOResult write_to_partition(AvbOps* ops, |
| 177 | const char* partition, |
| 178 | int64_t offset, |
| 179 | size_t num_bytes, |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 180 | const void* buffer) { |
| 181 | int fd; |
| 182 | off_t where; |
| 183 | ssize_t num_written; |
| 184 | AvbIOResult ret; |
| 185 | |
| 186 | fd = open_partition(partition, O_WRONLY); |
| 187 | if (fd == -1) { |
| 188 | avb_errorv("Error opening \"", partition, "\" partition.\n", NULL); |
| 189 | ret = AVB_IO_RESULT_ERROR_IO; |
| 190 | goto out; |
| 191 | } |
| 192 | |
| 193 | where = lseek(fd, offset, SEEK_SET); |
| 194 | if (where == -1) { |
| 195 | avb_error("Error seeking to offset.\n"); |
| 196 | ret = AVB_IO_RESULT_ERROR_IO; |
| 197 | goto out; |
| 198 | } |
| 199 | if (where != offset) { |
| 200 | avb_error("Error seeking to offset.\n"); |
| 201 | ret = AVB_IO_RESULT_ERROR_RANGE_OUTSIDE_PARTITION; |
| 202 | goto out; |
| 203 | } |
| 204 | |
| 205 | /* On Linux, we never get partial writes on block devices. */ |
| 206 | num_written = write(fd, buffer, num_bytes); |
| 207 | if (num_written == -1) { |
| 208 | avb_error("Error writing data.\n"); |
| 209 | ret = AVB_IO_RESULT_ERROR_IO; |
| 210 | goto out; |
| 211 | } |
| 212 | |
| 213 | ret = AVB_IO_RESULT_OK; |
| 214 | |
| 215 | out: |
| 216 | if (fd != -1) { |
| 217 | if (close(fd) != 0) { |
| 218 | avb_error("Error closing file descriptor.\n"); |
| 219 | } |
| 220 | } |
| 221 | return ret; |
| 222 | } |
| 223 | |
David Zeuthen | 3a58015 | 2017-04-12 15:50:47 -0400 | [diff] [blame] | 224 | static AvbIOResult validate_vbmeta_public_key( |
| 225 | AvbOps* ops, |
| 226 | const uint8_t* public_key_data, |
| 227 | size_t public_key_length, |
| 228 | const uint8_t* public_key_metadata, |
| 229 | size_t public_key_metadata_length, |
| 230 | bool* out_is_trusted) { |
| 231 | if (out_is_trusted != NULL) { |
| 232 | *out_is_trusted = true; |
| 233 | } |
| 234 | return AVB_IO_RESULT_OK; |
| 235 | } |
| 236 | |
| 237 | static AvbIOResult read_rollback_index(AvbOps* ops, |
| 238 | size_t rollback_index_location, |
| 239 | uint64_t* out_rollback_index) { |
| 240 | if (out_rollback_index != NULL) { |
| 241 | *out_rollback_index = 0; |
| 242 | } |
| 243 | return AVB_IO_RESULT_OK; |
| 244 | } |
| 245 | |
| 246 | static AvbIOResult write_rollback_index(AvbOps* ops, |
| 247 | size_t rollback_index_location, |
| 248 | uint64_t rollback_index) { |
| 249 | return AVB_IO_RESULT_OK; |
| 250 | } |
| 251 | |
| 252 | static AvbIOResult read_is_device_unlocked(AvbOps* ops, bool* out_is_unlocked) { |
| 253 | if (out_is_unlocked != NULL) { |
| 254 | *out_is_unlocked = true; |
| 255 | } |
| 256 | return AVB_IO_RESULT_OK; |
| 257 | } |
| 258 | |
David Zeuthen | 27a291f | 2017-04-27 18:18:33 -0400 | [diff] [blame] | 259 | static AvbIOResult get_size_of_partition(AvbOps* ops, |
| 260 | const char* partition, |
| 261 | uint64_t* out_size_in_bytes) { |
| 262 | int fd; |
| 263 | AvbIOResult ret; |
| 264 | |
| 265 | fd = open_partition(partition, O_WRONLY); |
| 266 | if (fd == -1) { |
| 267 | avb_errorv("Error opening \"", partition, "\" partition.\n", NULL); |
| 268 | ret = AVB_IO_RESULT_ERROR_IO; |
| 269 | goto out; |
| 270 | } |
| 271 | |
| 272 | if (out_size_in_bytes != NULL) { |
| 273 | if (ioctl(fd, BLKGETSIZE64, out_size_in_bytes) != 0) { |
| 274 | avb_errorv( |
| 275 | "Error getting size of \"", partition, "\" partition.\n", NULL); |
| 276 | ret = AVB_IO_RESULT_ERROR_IO; |
| 277 | goto out; |
| 278 | } |
| 279 | } |
| 280 | |
| 281 | ret = AVB_IO_RESULT_OK; |
| 282 | |
| 283 | out: |
| 284 | if (fd != -1) { |
| 285 | if (close(fd) != 0) { |
| 286 | avb_error("Error closing file descriptor.\n"); |
| 287 | } |
| 288 | } |
| 289 | return ret; |
| 290 | } |
| 291 | |
David Zeuthen | 3a58015 | 2017-04-12 15:50:47 -0400 | [diff] [blame] | 292 | static AvbIOResult get_unique_guid_for_partition(AvbOps* ops, |
| 293 | const char* partition, |
| 294 | char* guid_buf, |
| 295 | size_t guid_buf_size) { |
| 296 | if (guid_buf != NULL && guid_buf_size > 0) { |
| 297 | guid_buf[0] = '\0'; |
| 298 | } |
| 299 | return AVB_IO_RESULT_OK; |
| 300 | } |
| 301 | |
David Zeuthen | 86fd178 | 2017-03-28 15:37:55 -0400 | [diff] [blame] | 302 | AvbOps* avb_ops_user_new(void) { |
| 303 | AvbOps* ops; |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 304 | |
David Zeuthen | 86fd178 | 2017-03-28 15:37:55 -0400 | [diff] [blame] | 305 | ops = calloc(1, sizeof(AvbOps)); |
| 306 | if (ops == NULL) { |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 307 | avb_error("Error allocating memory for AvbOps.\n"); |
| 308 | goto out; |
| 309 | } |
| 310 | |
David Zeuthen | 86fd178 | 2017-03-28 15:37:55 -0400 | [diff] [blame] | 311 | ops->ab_ops = calloc(1, sizeof(AvbABOps)); |
| 312 | if (ops->ab_ops == NULL) { |
| 313 | avb_error("Error allocating memory for AvbABOps.\n"); |
| 314 | free(ops); |
| 315 | goto out; |
| 316 | } |
| 317 | ops->ab_ops->ops = ops; |
| 318 | |
| 319 | ops->read_from_partition = read_from_partition; |
| 320 | ops->write_to_partition = write_to_partition; |
David Zeuthen | 3a58015 | 2017-04-12 15:50:47 -0400 | [diff] [blame] | 321 | ops->validate_vbmeta_public_key = validate_vbmeta_public_key; |
| 322 | ops->read_rollback_index = read_rollback_index; |
| 323 | ops->write_rollback_index = write_rollback_index; |
| 324 | ops->read_is_device_unlocked = read_is_device_unlocked; |
| 325 | ops->get_unique_guid_for_partition = get_unique_guid_for_partition; |
David Zeuthen | 27a291f | 2017-04-27 18:18:33 -0400 | [diff] [blame] | 326 | ops->get_size_of_partition = get_size_of_partition; |
David Zeuthen | 86fd178 | 2017-03-28 15:37:55 -0400 | [diff] [blame] | 327 | ops->ab_ops->read_ab_metadata = avb_ab_data_read; |
| 328 | ops->ab_ops->write_ab_metadata = avb_ab_data_write; |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 329 | |
| 330 | out: |
David Zeuthen | 86fd178 | 2017-03-28 15:37:55 -0400 | [diff] [blame] | 331 | return ops; |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 332 | } |
| 333 | |
David Zeuthen | 86fd178 | 2017-03-28 15:37:55 -0400 | [diff] [blame] | 334 | void avb_ops_user_free(AvbOps* ops) { |
| 335 | free(ops->ab_ops); |
| 336 | free(ops); |
David Zeuthen | 4b6a634 | 2017-01-03 15:19:56 -0500 | [diff] [blame] | 337 | } |