tools/bootconfig/main.c

   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
  15 #include <linux/kernel.h>
  16 #include <linux/bootconfig.h>
  17
  18 static int xbc_show_value(struct xbc_node *node, bool semicolon)
  19 {
  20         const char *val, *eol;
  21         char q;
  22         int i = 0;
  23
  24         eol = semicolon ? ";\n" : "\n";
  25         xbc_array_for_each_value(node, val) {
  26                 if (strchr(val, '"'))
  27                         q = '\'';
  28                 else
  29                         q = '"';
  30                 printf("%c%s%c%s", q, val, q, node->next ? ", " : eol);
  31                 i++;
  32         }
  33         return i;
  34 }
  35
  36 static void xbc_show_compact_tree(void)
  37 {
  38         struct xbc_node *node, *cnode;
  39         int depth = 0, i;
  40
  41         node = xbc_root_node();
  42         while (node && xbc_node_is_key(node)) {
  43                 for (i = 0; i < depth; i++)
  44                         printf("\t");
  45                 cnode = xbc_node_get_child(node);
  46                 while (cnode && xbc_node_is_key(cnode) && !cnode->next) {
  47                         printf("%s.", xbc_node_get_data(node));
  48                         node = cnode;
  49                         cnode = xbc_node_get_child(node);
  50                 }
  51                 if (cnode && xbc_node_is_key(cnode)) {
  52                         printf("%s {\n", xbc_node_get_data(node));
  53                         depth++;
  54                         node = cnode;
  55                         continue;
  56                 } else if (cnode && xbc_node_is_value(cnode)) {
  57                         printf("%s = ", xbc_node_get_data(node));
  58                         xbc_show_value(cnode, true);
  59                 } else {
  60                         printf("%s;\n", xbc_node_get_data(node));
  61                 }
  62
  63                 if (node->next) {
  64                         node = xbc_node_get_next(node);
  65                         continue;
  66                 }
  67                 while (!node->next) {
  68                         node = xbc_node_get_parent(node);
  69                         if (!node)
  70                                 return;
  71                         if (!xbc_node_get_child(node)->next)
  72                                 continue;
  73                         depth--;
  74                         for (i = 0; i < depth; i++)
  75                                 printf("\t");
  76                         printf("}\n");
  77                 }
  78                 node = xbc_node_get_next(node);
  79         }
  80 }
  81
  82 static void xbc_show_list(void)
  83 {
  84         char key[XBC_KEYLEN_MAX];
  85         struct xbc_node *leaf;
  86         const char *val;
  87         int ret = 0;
  88
  89         xbc_for_each_key_value(leaf, val) {
  90                 ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX);
  91                 if (ret < 0)
  92                         break;
  93                 printf("%s = ", key);
  94                 if (!val || val[0] == '\0') {
  95                         printf("\"\"\n");
  96                         continue;
  97                 }
  98                 xbc_show_value(xbc_node_get_child(leaf), false);
  99         }
 100 }
 101
 102 /* Simple real checksum */
 103 static int checksum(unsigned char *buf, int len)
 104 {
 105         int i, sum = 0;
 106
 107         for (i = 0; i < len; i++)
 108                 sum += buf[i];
 109
 110         return sum;
 111 }
 112
 113 #define PAGE_SIZE       4096
 114
 115 static int load_xbc_fd(int fd, char **buf, int size)
 116 {
 117         int ret;
 118
 119         *buf = malloc(size + 1);
 120         if (!*buf)
 121                 return -ENOMEM;
 122
 123         ret = read(fd, *buf, size);
 124         if (ret < 0)
 125                 return -errno;
 126         (*buf)[size] = '\0';
 127
 128         return ret;
 129 }
 130
 131 /* Return the read size or -errno */
 132 static int load_xbc_file(const char *path, char **buf)
 133 {
 134         struct stat stat;
 135         int fd, ret;
 136
 137         fd = open(path, O_RDONLY);
 138         if (fd < 0)
 139                 return -errno;
 140         ret = fstat(fd, &stat);
 141         if (ret < 0)
 142                 return -errno;
 143
 144         ret = load_xbc_fd(fd, buf, stat.st_size);
 145
 146         close(fd);
 147
 148         return ret;
 149 }
 150
 151 static int pr_errno(const char *msg, int err)
 152 {
 153         pr_err("%s: %d\n", msg, err);
 154         return err;
 155 }
 156
 157 static int load_xbc_from_initrd(int fd, char **buf)
 158 {
 159         struct stat stat;
 160         int ret;
 161         u32 size = 0, csum = 0, rcsum;
 162         char magic[BOOTCONFIG_MAGIC_LEN];
 163         const char *msg;
 164
 165         ret = fstat(fd, &stat);
 166         if (ret < 0)
 167                 return -errno;
 168
 169         if (stat.st_size < 8 + BOOTCONFIG_MAGIC_LEN)
 170                 return 0;
 171
 172         if (lseek(fd, -BOOTCONFIG_MAGIC_LEN, SEEK_END) < 0)
 173                 return pr_errno("Failed to lseek for magic", -errno);
 174
 175         if (read(fd, magic, BOOTCONFIG_MAGIC_LEN) < 0)
 176                 return pr_errno("Failed to read", -errno);
 177
 178         /* Check the bootconfig magic bytes */
 179         if (memcmp(magic, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN) != 0)
 180                 return 0;
 181
 182         if (lseek(fd, -(8 + BOOTCONFIG_MAGIC_LEN), SEEK_END) < 0)
 183                 return pr_errno("Failed to lseek for size", -errno);
 184
 185         if (read(fd, &size, sizeof(u32)) < 0)
 186                 return pr_errno("Failed to read size", -errno);
 187         size = le32toh(size);
 188
 189         if (read(fd, &csum, sizeof(u32)) < 0)
 190                 return pr_errno("Failed to read checksum", -errno);
 191         csum = le32toh(csum);
 192
 193         /* Wrong size error  */
 194         if (stat.st_size < size + 8 + BOOTCONFIG_MAGIC_LEN) {
 195                 pr_err("bootconfig size is too big\n");
 196                 return -E2BIG;
 197         }
 198
 199         if (lseek(fd, stat.st_size - (size + 8 + BOOTCONFIG_MAGIC_LEN),
 200                   SEEK_SET) < 0)
 201                 return pr_errno("Failed to lseek", -errno);
 202
 203         ret = load_xbc_fd(fd, buf, size);
 204         if (ret < 0)
 205                 return ret;
 206
 207         /* Wrong Checksum */
 208         rcsum = checksum((unsigned char *)*buf, size);
 209         if (csum != rcsum) {
 210                 pr_err("checksum error: %d != %d\n", csum, rcsum);
 211                 return -EINVAL;
 212         }
 213
 214         ret = xbc_init(*buf, &msg, NULL);
 215         /* Wrong data */
 216         if (ret < 0) {
 217                 pr_err("parse error: %s.\n", msg);
 218                 return ret;
 219         }
 220
 221         return size;
 222 }
 223
 224 static void show_xbc_error(const char *data, const char *msg, int pos)
 225 {
 226         int lin = 1, col, i;
 227
 228         if (pos < 0) {
 229                 pr_err("Error: %s.\n", msg);
 230                 return;
 231         }
 232
 233         /* Note that pos starts from 0 but lin and col should start from 1. */
 234         col = pos + 1;
 235         for (i = 0; i < pos; i++) {
 236                 if (data[i] == '\n') {
 237                         lin++;
 238                         col = pos - i;
 239                 }
 240         }
 241         pr_err("Parse Error: %s at %d:%d\n", msg, lin, col);
 242
 243 }
 244
 245 static int init_xbc_with_error(char *buf, int len)
 246 {
 247         char *copy = strdup(buf);
 248         const char *msg;
 249         int ret, pos;
 250
 251         if (!copy)
 252                 return -ENOMEM;
 253
 254         ret = xbc_init(buf, &msg, &pos);
 255         if (ret < 0)
 256                 show_xbc_error(copy, msg, pos);
 257         free(copy);
 258
 259         return ret;
 260 }
 261
 262 static int show_xbc(const char *path, bool list)
 263 {
 264         int ret, fd;
 265         char *buf = NULL;
 266         struct stat st;
 267
 268         ret = stat(path, &st);
 269         if (ret < 0) {
 270                 ret = -errno;
 271                 pr_err("Failed to stat %s: %d\n", path, ret);
 272                 return ret;
 273         }
 274
 275         fd = open(path, O_RDONLY);
 276         if (fd < 0) {
 277                 ret = -errno;
 278                 pr_err("Failed to open initrd %s: %d\n", path, ret);
 279                 return ret;
 280         }
 281
 282         ret = load_xbc_from_initrd(fd, &buf);
 283         close(fd);
 284         if (ret < 0) {
 285                 pr_err("Failed to load a boot config from initrd: %d\n", ret);
 286                 goto out;
 287         }
 288         /* Assume a bootconfig file if it is enough small */
 289         if (ret == 0 && st.st_size <= XBC_DATA_MAX) {
 290                 ret = load_xbc_file(path, &buf);
 291                 if (ret < 0) {
 292                         pr_err("Failed to load a boot config: %d\n", ret);
 293                         goto out;
 294                 }
 295                 if (init_xbc_with_error(buf, ret) < 0)
 296                         goto out;
 297         }
 298         if (list)
 299                 xbc_show_list();
 300         else
 301                 xbc_show_compact_tree();
 302         ret = 0;
 303 out:
 304         free(buf);
 305
 306         return ret;
 307 }
 308
 309 static int delete_xbc(const char *path)
 310 {
 311         struct stat stat;
 312         int ret = 0, fd, size;
 313         char *buf = NULL;
 314
 315         fd = open(path, O_RDWR);
 316         if (fd < 0) {
 317                 ret = -errno;
 318                 pr_err("Failed to open initrd %s: %d\n", path, ret);
 319                 return ret;
 320         }
 321
 322         size = load_xbc_from_initrd(fd, &buf);
 323         if (size < 0) {
 324                 ret = size;
 325                 pr_err("Failed to load a boot config from initrd: %d\n", ret);
 326         } else if (size > 0) {
 327                 ret = fstat(fd, &stat);
 328                 if (!ret)
 329                         ret = ftruncate(fd, stat.st_size
 330                                         - size - 8 - BOOTCONFIG_MAGIC_LEN);
 331                 if (ret)
 332                         ret = -errno;
 333         } /* Ignore if there is no boot config in initrd */
 334
 335         close(fd);
 336         free(buf);
 337
 338         return ret;
 339 }
 340
 341 static int apply_xbc(const char *path, const char *xbc_path)
 342 {
 343         char *buf, *data, *p;
 344         size_t total_size;
 345         struct stat stat;
 346         const char *msg;
 347         u32 size, csum;
 348         int pos, pad;
 349         int ret, fd;
 350
 351         ret = load_xbc_file(xbc_path, &buf);
 352         if (ret < 0) {
 353                 pr_err("Failed to load %s : %d\n", xbc_path, ret);
 354                 return ret;
 355         }
 356         size = strlen(buf) + 1;
 357         csum = checksum((unsigned char *)buf, size);
 358
 359         /* Backup the bootconfig data */
 360         data = calloc(size + BOOTCONFIG_ALIGN +
 361                       sizeof(u32) + sizeof(u32) + BOOTCONFIG_MAGIC_LEN, 1);
 362         if (!data)
 363                 return -ENOMEM;
 364         memcpy(data, buf, size);
 365
 366         /* Check the data format */
 367         ret = xbc_init(buf, &msg, &pos);
 368         if (ret < 0) {
 369                 show_xbc_error(data, msg, pos);
 370                 free(data);
 371                 free(buf);
 372
 373                 return ret;
 374         }
 375         printf("Apply %s to %s\n", xbc_path, path);
 376         printf("\tNumber of nodes: %d\n", ret);
 377         printf("\tSize: %u bytes\n", (unsigned int)size);
 378         printf("\tChecksum: %d\n", (unsigned int)csum);
 379
 380         /* TODO: Check the options by schema */
 381         xbc_destroy_all();
 382         free(buf);
 383
 384         /* Remove old boot config if exists */
 385         ret = delete_xbc(path);
 386         if (ret < 0) {
 387                 pr_err("Failed to delete previous boot config: %d\n", ret);
 388                 free(data);
 389                 return ret;
 390         }
 391
 392         /* Apply new one */
 393         fd = open(path, O_RDWR | O_APPEND);
 394         if (fd < 0) {
 395                 ret = -errno;
 396                 pr_err("Failed to open %s: %d\n", path, ret);
 397                 free(data);
 398                 return ret;
 399         }
 400         /* TODO: Ensure the @path is initramfs/initrd image */
 401         if (fstat(fd, &stat) < 0) {
 402                 pr_err("Failed to get the size of %s\n", path);
 403                 goto out;
 404         }
 405
 406         /* To align up the total size to BOOTCONFIG_ALIGN, get padding size */
 407         total_size = stat.st_size + size + sizeof(u32) * 2 + BOOTCONFIG_MAGIC_LEN;
 408         pad = ((total_size + BOOTCONFIG_ALIGN - 1) & (~BOOTCONFIG_ALIGN_MASK)) - total_size;
 409         size += pad;
 410
 411         /* Add a footer */
 412         p = data + size;
 413         *(u32 *)p = htole32(size);
 414         p += sizeof(u32);
 415
 416         *(u32 *)p = htole32(csum);
 417         p += sizeof(u32);
 418
 419         memcpy(p, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
 420         p += BOOTCONFIG_MAGIC_LEN;
 421
 422         total_size = p - data;
 423
 424         ret = write(fd, data, total_size);
 425         if (ret < total_size) {
 426                 if (ret < 0)
 427                         ret = -errno;
 428                 pr_err("Failed to apply a boot config: %d\n", ret);
 429                 if (ret >= 0)
 430                         goto out_rollback;
 431         } else
 432                 ret = 0;
 433
 434 out:
 435         close(fd);
 436         free(data);
 437
 438         return ret;
 439
 440 out_rollback:
 441         /* Map the partial write to -ENOSPC */
 442         if (ret >= 0)
 443                 ret = -ENOSPC;
 444         if (ftruncate(fd, stat.st_size) < 0) {
 445                 ret = -errno;
 446                 pr_err("Failed to rollback the write error: %d\n", ret);
 447                 pr_err("The initrd %s may be corrupted. Recommend to rebuild.\n", path);
 448         }
 449         goto out;
 450 }
 451
 452 static int usage(void)
 453 {
 454         printf("Usage: bootconfig [OPTIONS] <INITRD>\n"
 455                 "Or     bootconfig <CONFIG>\n"
 456                 " Apply, delete or show boot config to initrd.\n"
 457                 " Options:\n"
 458                 "               -a <config>: Apply boot config to initrd\n"
 459                 "               -d : Delete boot config file from initrd\n"
 460                 "               -l : list boot config in initrd or file\n\n"
 461                 " If no option is given, show the bootconfig in the given file.\n");
 462         return -1;
 463 }
 464
 465 int main(int argc, char **argv)
 466 {
 467         char *path = NULL;
 468         char *apply = NULL;
 469         bool delete = false, list = false;
 470         int opt;
 471
 472         while ((opt = getopt(argc, argv, "hda:l")) != -1) {
 473                 switch (opt) {
 474                 case 'd':
 475                         delete = true;
 476                         break;
 477                 case 'a':
 478                         apply = optarg;
 479                         break;
 480                 case 'l':
 481                         list = true;
 482                         break;
 483                 case 'h':
 484                 default:
 485                         return usage();
 486                 }
 487         }
 488
 489         if ((apply && delete) || (delete && list) || (apply && list)) {
 490                 pr_err("Error: You can give one of -a, -d or -l at once.\n");
 491                 return usage();
 492         }
 493
 494         if (optind >= argc) {
 495                 pr_err("Error: No initrd is specified.\n");
 496                 return usage();
 497         }
 498
 499         path = argv[optind];
 500
 501         if (apply)
 502                 return apply_xbc(path, apply);
 503         else if (delete)
 504                 return delete_xbc(path);
 505
 506         return show_xbc(path, list);
 507 }