1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Boot config tool for initrd image 4 */ 5 #include <stdio.h> 6 #include <stdlib.h> 7 #include <sys/types.h> 8 #include <sys/stat.h> 9 #include <fcntl.h> 10 #include <unistd.h> 11 #include <string.h> 12 #include <errno.h> 13 #include <endian.h> 14 #include <assert.h> 15 16 #include <linux/bootconfig.h> 17 18 #define pr_err(fmt, ...) fprintf(stderr, fmt, ##__VA_ARGS__) 19 20 /* Bootconfig footer is [size][csum][BOOTCONFIG_MAGIC]. */ 21 #define BOOTCONFIG_FOOTER_SIZE \ 22 (sizeof(uint32_t) * 2 + BOOTCONFIG_MAGIC_LEN) 23 24 static int xbc_show_value(struct xbc_node *node, bool semicolon) 25 { 26 const char *val, *eol; 27 char q; 28 int i = 0; 29 30 eol = semicolon ? ";\n" : "\n"; 31 xbc_array_for_each_value(node, val) { 32 if (strchr(val, '"')) 33 q = '\''; 34 else 35 q = '"'; 36 printf("%c%s%c%s", q, val, q, xbc_node_is_array(node) ? ", " : eol); 37 i++; 38 } 39 return i; 40 } 41 42 static void xbc_show_compact_tree(void) 43 { 44 struct xbc_node *node, *cnode = NULL, *vnode; 45 int depth = 0, i; 46 47 node = xbc_root_node(); 48 while (node && xbc_node_is_key(node)) { 49 for (i = 0; i < depth; i++) 50 printf("\t"); 51 if (!cnode) 52 cnode = xbc_node_get_child(node); 53 while (cnode && xbc_node_is_key(cnode) && !cnode->next) { 54 vnode = xbc_node_get_child(cnode); 55 /* 56 * If @cnode has value and subkeys, this 57 * should show it as below. 58 * 59 * key(@node) { 60 * key(@cnode) = value; 61 * key(@cnode) { 62 * subkeys; 63 * } 64 * } 65 */ 66 if (vnode && xbc_node_is_value(vnode) && vnode->next) 67 break; 68 printf("%s.", xbc_node_get_data(node)); 69 node = cnode; 70 cnode = vnode; 71 } 72 if (cnode && xbc_node_is_key(cnode)) { 73 printf("%s {\n", xbc_node_get_data(node)); 74 depth++; 75 node = cnode; 76 cnode = NULL; 77 continue; 78 } else if (cnode && xbc_node_is_value(cnode)) { 79 printf("%s = ", xbc_node_get_data(node)); 80 xbc_show_value(cnode, true); 81 /* 82 * If @node has value and subkeys, continue 83 * looping on subkeys with same node. 84 */ 85 if (cnode->next) { 86 cnode = xbc_node_get_next(cnode); 87 continue; 88 } 89 } else { 90 printf("%s;\n", xbc_node_get_data(node)); 91 } 92 cnode = NULL; 93 94 if (node->next) { 95 node = xbc_node_get_next(node); 96 continue; 97 } 98 while (!node->next) { 99 node = xbc_node_get_parent(node); 100 if (!node) 101 return; 102 if (!xbc_node_get_child(node)->next) 103 continue; 104 if (depth) { 105 depth--; 106 for (i = 0; i < depth; i++) 107 printf("\t"); 108 printf("}\n"); 109 } 110 } 111 node = xbc_node_get_next(node); 112 } 113 } 114 115 static void xbc_show_list(void) 116 { 117 char key[XBC_KEYLEN_MAX]; 118 struct xbc_node *leaf; 119 const char *val; 120 int ret; 121 122 xbc_for_each_key_value(leaf, val) { 123 ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX); 124 if (ret < 0) { 125 fprintf(stderr, "Failed to compose key %d\n", ret); 126 break; 127 } 128 printf("%s = ", key); 129 if (!val || val[0] == '\0') { 130 printf("\"\"\n"); 131 continue; 132 } 133 xbc_show_value(xbc_node_get_child(leaf), false); 134 } 135 } 136 137 #define PAGE_SIZE 4096 138 139 static int load_xbc_fd(int fd, char **buf, int size) 140 { 141 int ret; 142 143 *buf = malloc(size + 1); 144 if (!*buf) 145 return -ENOMEM; 146 147 ret = read(fd, *buf, size); 148 if (ret < 0) 149 return -errno; 150 (*buf)[size] = '\0'; 151 152 return ret; 153 } 154 155 /* Return the read size or -errno */ 156 static int load_xbc_file(const char *path, char **buf) 157 { 158 struct stat stat; 159 int fd, ret; 160 161 fd = open(path, O_RDONLY); 162 if (fd < 0) 163 return -errno; 164 ret = fstat(fd, &stat); 165 if (ret < 0) { 166 ret = -errno; 167 close(fd); 168 return ret; 169 } 170 171 ret = load_xbc_fd(fd, buf, stat.st_size); 172 173 close(fd); 174 175 return ret; 176 } 177 178 static int pr_errno(const char *msg, int err) 179 { 180 pr_err("%s: %d\n", msg, err); 181 return err; 182 } 183 184 static int load_xbc_from_initrd(int fd, char **buf) 185 { 186 struct stat stat; 187 int ret; 188 uint32_t size = 0, csum = 0, rcsum; 189 char magic[BOOTCONFIG_MAGIC_LEN]; 190 const char *msg; 191 192 ret = fstat(fd, &stat); 193 if (ret < 0) 194 return -errno; 195 196 if (stat.st_size < BOOTCONFIG_FOOTER_SIZE) 197 return 0; 198 199 if (lseek(fd, -(off_t)BOOTCONFIG_MAGIC_LEN, SEEK_END) < 0) 200 return pr_errno("Failed to lseek for magic", -errno); 201 202 if (read(fd, magic, BOOTCONFIG_MAGIC_LEN) < 0) 203 return pr_errno("Failed to read", -errno); 204 205 /* Check the bootconfig magic bytes */ 206 if (memcmp(magic, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN) != 0) 207 return 0; 208 209 if (lseek(fd, -(off_t)BOOTCONFIG_FOOTER_SIZE, SEEK_END) < 0) 210 return pr_errno("Failed to lseek for size", -errno); 211 212 if (read(fd, &size, sizeof(uint32_t)) < 0) 213 return pr_errno("Failed to read size", -errno); 214 size = le32toh(size); 215 216 if (read(fd, &csum, sizeof(uint32_t)) < 0) 217 return pr_errno("Failed to read checksum", -errno); 218 csum = le32toh(csum); 219 220 /* Wrong size error */ 221 if (stat.st_size < size + BOOTCONFIG_FOOTER_SIZE) { 222 pr_err("bootconfig size is too big\n"); 223 return -E2BIG; 224 } 225 226 if (lseek(fd, stat.st_size - (size + BOOTCONFIG_FOOTER_SIZE), 227 SEEK_SET) < 0) 228 return pr_errno("Failed to lseek", -errno); 229 230 ret = load_xbc_fd(fd, buf, size); 231 if (ret < 0) 232 return ret; 233 234 /* Wrong Checksum */ 235 rcsum = xbc_calc_checksum(*buf, size); 236 if (csum != rcsum) { 237 pr_err("checksum error: %u != %u\n", csum, rcsum); 238 return -EINVAL; 239 } 240 241 ret = xbc_init(*buf, size, &msg, NULL); 242 /* Wrong data */ 243 if (ret < 0) { 244 pr_err("parse error: %s.\n", msg); 245 return ret; 246 } 247 248 return size; 249 } 250 251 static void show_xbc_error(const char *data, const char *msg, int pos) 252 { 253 int lin = 1, col, i; 254 255 if (pos < 0) { 256 pr_err("Error: %s.\n", msg); 257 return; 258 } 259 260 /* Note that pos starts from 0 but lin and col should start from 1. */ 261 col = pos + 1; 262 for (i = 0; i < pos; i++) { 263 if (data[i] == '\n') { 264 lin++; 265 col = pos - i; 266 } 267 } 268 pr_err("Parse Error: %s at %d:%d\n", msg, lin, col); 269 270 } 271 272 static int init_xbc_with_error(char *buf, int len) 273 { 274 char *copy = strdup(buf); 275 const char *msg; 276 int ret, pos; 277 278 if (!copy) 279 return -ENOMEM; 280 281 ret = xbc_init(buf, len, &msg, &pos); 282 if (ret < 0) 283 show_xbc_error(copy, msg, pos); 284 free(copy); 285 286 return ret; 287 } 288 289 static int show_xbc_kernel_cmdline(void) 290 { 291 struct xbc_node *root; 292 char *buf = NULL; 293 int len, ret; 294 295 root = xbc_find_node("kernel"); 296 if (!root) 297 return 0; /* no kernel.* keys: emit empty output */ 298 299 len = xbc_snprint_cmdline(NULL, 0, root); 300 if (len < 0) { 301 pr_err("Failed to size cmdline output: %d\n", len); 302 return len; 303 } 304 if (len == 0) 305 return 0; 306 307 buf = malloc(len + 1); 308 if (!buf) 309 return -ENOMEM; 310 311 ret = xbc_snprint_cmdline(buf, len + 1, root); 312 if (ret < 0) { 313 pr_err("Failed to render cmdline output: %d\n", ret); 314 free(buf); 315 return ret; 316 } 317 318 fputs(buf, stdout); 319 free(buf); 320 return 0; 321 } 322 323 static int show_xbc(const char *path, bool list, bool render_cmdline) 324 { 325 int ret, fd; 326 char *buf = NULL; 327 struct stat st; 328 329 ret = stat(path, &st); 330 if (ret < 0) { 331 ret = -errno; 332 pr_err("Failed to stat %s: %d\n", path, ret); 333 return ret; 334 } 335 336 fd = open(path, O_RDONLY); 337 if (fd < 0) { 338 ret = -errno; 339 pr_err("Failed to open initrd %s: %d\n", path, ret); 340 return ret; 341 } 342 343 ret = load_xbc_from_initrd(fd, &buf); 344 close(fd); 345 if (ret < 0) { 346 pr_err("Failed to load a boot config from initrd: %d\n", ret); 347 goto out; 348 } 349 /* Assume a bootconfig file if it is enough small */ 350 if (ret == 0 && st.st_size <= XBC_DATA_MAX) { 351 ret = load_xbc_file(path, &buf); 352 if (ret < 0) { 353 pr_err("Failed to load a boot config: %d\n", ret); 354 goto out; 355 } 356 if (init_xbc_with_error(buf, ret) < 0) 357 goto out; 358 } 359 if (render_cmdline) 360 ret = show_xbc_kernel_cmdline(); 361 else if (list) 362 xbc_show_list(); 363 else 364 xbc_show_compact_tree(); 365 if (ret > 0) 366 ret = 0; 367 out: 368 free(buf); 369 370 return ret; 371 } 372 373 static int delete_xbc(const char *path) 374 { 375 struct stat stat; 376 int ret = 0, fd, size; 377 char *buf = NULL; 378 379 fd = open(path, O_RDWR); 380 if (fd < 0) { 381 ret = -errno; 382 pr_err("Failed to open initrd %s: %d\n", path, ret); 383 return ret; 384 } 385 386 size = load_xbc_from_initrd(fd, &buf); 387 if (size < 0) { 388 ret = size; 389 pr_err("Failed to load a boot config from initrd: %d\n", ret); 390 } else if (size > 0) { 391 ret = fstat(fd, &stat); 392 if (!ret) 393 ret = ftruncate(fd, stat.st_size 394 - size - BOOTCONFIG_FOOTER_SIZE); 395 if (ret) 396 ret = -errno; 397 } /* Ignore if there is no boot config in initrd */ 398 399 close(fd); 400 free(buf); 401 402 return ret; 403 } 404 405 static int apply_xbc(const char *path, const char *xbc_path) 406 { 407 struct { 408 uint32_t size; 409 uint32_t csum; 410 char magic[BOOTCONFIG_MAGIC_LEN]; 411 } footer; 412 char *buf, *data; 413 size_t total_size; 414 struct stat stat; 415 const char *msg; 416 uint32_t size, csum; 417 int pos, pad; 418 int ret, fd; 419 420 ret = load_xbc_file(xbc_path, &buf); 421 if (ret < 0) { 422 pr_err("Failed to load %s : %d\n", xbc_path, ret); 423 return ret; 424 } 425 size = strlen(buf) + 1; 426 csum = xbc_calc_checksum(buf, size); 427 428 /* Backup the bootconfig data */ 429 data = calloc(size + BOOTCONFIG_ALIGN + BOOTCONFIG_FOOTER_SIZE, 1); 430 if (!data) { 431 free(buf); 432 return -ENOMEM; 433 } 434 memcpy(data, buf, size); 435 436 /* Check the data format */ 437 ret = xbc_init(buf, size, &msg, &pos); 438 if (ret < 0) { 439 show_xbc_error(data, msg, pos); 440 free(data); 441 free(buf); 442 443 return ret; 444 } 445 printf("Apply %s to %s\n", xbc_path, path); 446 xbc_get_info(&ret, NULL); 447 printf("\tNumber of nodes: %d\n", ret); 448 printf("\tSize: %u bytes\n", (unsigned int)size); 449 printf("\tChecksum: %u\n", (unsigned int)csum); 450 451 /* TODO: Check the options by schema */ 452 xbc_exit(); 453 free(buf); 454 455 /* Remove old boot config if exists */ 456 ret = delete_xbc(path); 457 if (ret < 0) { 458 pr_err("Failed to delete previous boot config: %d\n", ret); 459 free(data); 460 return ret; 461 } 462 463 /* Apply new one */ 464 fd = open(path, O_RDWR | O_APPEND); 465 if (fd < 0) { 466 ret = -errno; 467 pr_err("Failed to open %s: %d\n", path, ret); 468 free(data); 469 return ret; 470 } 471 /* TODO: Ensure the @path is initramfs/initrd image */ 472 if (fstat(fd, &stat) < 0) { 473 ret = -errno; 474 pr_err("Failed to get the size of %s\n", path); 475 goto out; 476 } 477 478 /* To align up the total size to BOOTCONFIG_ALIGN, get padding size */ 479 total_size = stat.st_size + size + BOOTCONFIG_FOOTER_SIZE; 480 pad = ((total_size + BOOTCONFIG_ALIGN - 1) & (~BOOTCONFIG_ALIGN_MASK)) - total_size; 481 size += pad; 482 483 /* Add a footer */ 484 footer.size = htole32(size); 485 footer.csum = htole32(csum); 486 memcpy(footer.magic, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN); 487 static_assert(sizeof(footer) == BOOTCONFIG_FOOTER_SIZE); 488 memcpy(data + size, &footer, BOOTCONFIG_FOOTER_SIZE); 489 490 total_size = size + BOOTCONFIG_FOOTER_SIZE; 491 492 ret = write(fd, data, total_size); 493 if (ret < total_size) { 494 if (ret < 0) 495 ret = -errno; 496 pr_err("Failed to apply a boot config: %d\n", ret); 497 if (ret >= 0) 498 goto out_rollback; 499 } else 500 ret = 0; 501 502 out: 503 close(fd); 504 free(data); 505 506 return ret; 507 508 out_rollback: 509 /* Map the partial write to -ENOSPC */ 510 if (ret >= 0) 511 ret = -ENOSPC; 512 if (ftruncate(fd, stat.st_size) < 0) { 513 ret = -errno; 514 pr_err("Failed to rollback the write error: %d\n", ret); 515 pr_err("The initrd %s may be corrupted. Recommend to rebuild.\n", path); 516 } 517 goto out; 518 } 519 520 static int usage(void) 521 { 522 printf("Usage: bootconfig [OPTIONS] <INITRD>\n" 523 "Or bootconfig <CONFIG>\n" 524 " Apply, delete or show boot config to initrd.\n" 525 " Options:\n" 526 " -a <config>: Apply boot config to initrd\n" 527 " -d : Delete boot config file from initrd\n" 528 " -l : list boot config in initrd or file\n" 529 " -C : render the kernel.* subtree as a flat cmdline\n" 530 " string (suitable for embedding in a kernel image)\n" 531 " and print it to stdout\n\n" 532 " If no option is given, show the bootconfig in the given file.\n"); 533 return -1; 534 } 535 536 int main(int argc, char **argv) 537 { 538 char *path = NULL; 539 char *apply = NULL; 540 bool render_cmdline = false; 541 bool delete = false, list = false; 542 int opt; 543 544 while ((opt = getopt(argc, argv, "hda:lC")) != -1) { 545 switch (opt) { 546 case 'd': 547 delete = true; 548 break; 549 case 'a': 550 apply = optarg; 551 break; 552 case 'l': 553 list = true; 554 break; 555 case 'C': 556 render_cmdline = true; 557 break; 558 case 'h': 559 default: 560 return usage(); 561 } 562 } 563 564 if ((!!apply + !!delete + !!list + !!render_cmdline) > 1) { 565 pr_err("Error: You can give one of -a, -d, -l or -C at once.\n"); 566 return usage(); 567 } 568 569 if (optind >= argc) { 570 pr_err("Error: No initrd is specified.\n"); 571 return usage(); 572 } 573 574 path = argv[optind]; 575 576 if (apply) 577 return apply_xbc(path, apply); 578 else if (delete) 579 return delete_xbc(path); 580 581 return show_xbc(path, list, render_cmdline); 582 } 583