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 14 #include <linux/kernel.h> 15 #include <linux/bootconfig.h> 16 17 static int xbc_show_value(struct xbc_node *node) 18 { 19 const char *val; 20 char q; 21 int i = 0; 22 23 xbc_array_for_each_value(node, val) { 24 if (strchr(val, '"')) 25 q = '\''; 26 else 27 q = '"'; 28 printf("%c%s%c%s", q, val, q, node->next ? ", " : ";\n"); 29 i++; 30 } 31 return i; 32 } 33 34 static void xbc_show_compact_tree(void) 35 { 36 struct xbc_node *node, *cnode; 37 int depth = 0, i; 38 39 node = xbc_root_node(); 40 while (node && xbc_node_is_key(node)) { 41 for (i = 0; i < depth; i++) 42 printf("\t"); 43 cnode = xbc_node_get_child(node); 44 while (cnode && xbc_node_is_key(cnode) && !cnode->next) { 45 printf("%s.", xbc_node_get_data(node)); 46 node = cnode; 47 cnode = xbc_node_get_child(node); 48 } 49 if (cnode && xbc_node_is_key(cnode)) { 50 printf("%s {\n", xbc_node_get_data(node)); 51 depth++; 52 node = cnode; 53 continue; 54 } else if (cnode && xbc_node_is_value(cnode)) { 55 printf("%s = ", xbc_node_get_data(node)); 56 xbc_show_value(cnode); 57 } else { 58 printf("%s;\n", xbc_node_get_data(node)); 59 } 60 61 if (node->next) { 62 node = xbc_node_get_next(node); 63 continue; 64 } 65 while (!node->next) { 66 node = xbc_node_get_parent(node); 67 if (!node) 68 return; 69 if (!xbc_node_get_child(node)->next) 70 continue; 71 depth--; 72 for (i = 0; i < depth; i++) 73 printf("\t"); 74 printf("}\n"); 75 } 76 node = xbc_node_get_next(node); 77 } 78 } 79 80 /* Simple real checksum */ 81 int checksum(unsigned char *buf, int len) 82 { 83 int i, sum = 0; 84 85 for (i = 0; i < len; i++) 86 sum += buf[i]; 87 88 return sum; 89 } 90 91 #define PAGE_SIZE 4096 92 93 int load_xbc_fd(int fd, char **buf, int size) 94 { 95 int ret; 96 97 *buf = malloc(size + 1); 98 if (!*buf) 99 return -ENOMEM; 100 101 ret = read(fd, *buf, size); 102 if (ret < 0) 103 return -errno; 104 (*buf)[size] = '\0'; 105 106 return ret; 107 } 108 109 /* Return the read size or -errno */ 110 int load_xbc_file(const char *path, char **buf) 111 { 112 struct stat stat; 113 int fd, ret; 114 115 fd = open(path, O_RDONLY); 116 if (fd < 0) 117 return -errno; 118 ret = fstat(fd, &stat); 119 if (ret < 0) 120 return -errno; 121 122 ret = load_xbc_fd(fd, buf, stat.st_size); 123 124 close(fd); 125 126 return ret; 127 } 128 129 int load_xbc_from_initrd(int fd, char **buf) 130 { 131 struct stat stat; 132 int ret; 133 u32 size = 0, csum = 0, rcsum; 134 char magic[BOOTCONFIG_MAGIC_LEN]; 135 const char *msg; 136 137 ret = fstat(fd, &stat); 138 if (ret < 0) 139 return -errno; 140 141 if (stat.st_size < 8 + BOOTCONFIG_MAGIC_LEN) 142 return 0; 143 144 if (lseek(fd, -BOOTCONFIG_MAGIC_LEN, SEEK_END) < 0) { 145 pr_err("Failed to lseek: %d\n", -errno); 146 return -errno; 147 } 148 if (read(fd, magic, BOOTCONFIG_MAGIC_LEN) < 0) 149 return -errno; 150 /* Check the bootconfig magic bytes */ 151 if (memcmp(magic, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN) != 0) 152 return 0; 153 154 if (lseek(fd, -(8 + BOOTCONFIG_MAGIC_LEN), SEEK_END) < 0) { 155 pr_err("Failed to lseek: %d\n", -errno); 156 return -errno; 157 } 158 159 if (read(fd, &size, sizeof(u32)) < 0) 160 return -errno; 161 162 if (read(fd, &csum, sizeof(u32)) < 0) 163 return -errno; 164 165 /* Wrong size error */ 166 if (stat.st_size < size + 8 + BOOTCONFIG_MAGIC_LEN) { 167 pr_err("bootconfig size is too big\n"); 168 return -E2BIG; 169 } 170 171 if (lseek(fd, stat.st_size - (size + 8 + BOOTCONFIG_MAGIC_LEN), 172 SEEK_SET) < 0) { 173 pr_err("Failed to lseek: %d\n", -errno); 174 return -errno; 175 } 176 177 ret = load_xbc_fd(fd, buf, size); 178 if (ret < 0) 179 return ret; 180 181 /* Wrong Checksum */ 182 rcsum = checksum((unsigned char *)*buf, size); 183 if (csum != rcsum) { 184 pr_err("checksum error: %d != %d\n", csum, rcsum); 185 return -EINVAL; 186 } 187 188 ret = xbc_init(*buf, &msg, NULL); 189 /* Wrong data */ 190 if (ret < 0) { 191 pr_err("parse error: %s.\n", msg); 192 return ret; 193 } 194 195 return size; 196 } 197 198 int show_xbc(const char *path) 199 { 200 int ret, fd; 201 char *buf = NULL; 202 203 fd = open(path, O_RDONLY); 204 if (fd < 0) { 205 pr_err("Failed to open initrd %s: %d\n", path, fd); 206 return -errno; 207 } 208 209 ret = load_xbc_from_initrd(fd, &buf); 210 if (ret < 0) { 211 pr_err("Failed to load a boot config from initrd: %d\n", ret); 212 goto out; 213 } 214 xbc_show_compact_tree(); 215 ret = 0; 216 out: 217 close(fd); 218 free(buf); 219 220 return ret; 221 } 222 223 int delete_xbc(const char *path) 224 { 225 struct stat stat; 226 int ret = 0, fd, size; 227 char *buf = NULL; 228 229 fd = open(path, O_RDWR); 230 if (fd < 0) { 231 pr_err("Failed to open initrd %s: %d\n", path, fd); 232 return -errno; 233 } 234 235 size = load_xbc_from_initrd(fd, &buf); 236 if (size < 0) { 237 ret = size; 238 pr_err("Failed to load a boot config from initrd: %d\n", ret); 239 } else if (size > 0) { 240 ret = fstat(fd, &stat); 241 if (!ret) 242 ret = ftruncate(fd, stat.st_size 243 - size - 8 - BOOTCONFIG_MAGIC_LEN); 244 if (ret) 245 ret = -errno; 246 } /* Ignore if there is no boot config in initrd */ 247 248 close(fd); 249 free(buf); 250 251 return ret; 252 } 253 254 static void show_xbc_error(const char *data, const char *msg, int pos) 255 { 256 int lin = 1, col, i; 257 258 if (pos < 0) { 259 pr_err("Error: %s.\n", msg); 260 return; 261 } 262 263 /* Note that pos starts from 0 but lin and col should start from 1. */ 264 col = pos + 1; 265 for (i = 0; i < pos; i++) { 266 if (data[i] == '\n') { 267 lin++; 268 col = pos - i; 269 } 270 } 271 pr_err("Parse Error: %s at %d:%d\n", msg, lin, col); 272 273 } 274 275 int apply_xbc(const char *path, const char *xbc_path) 276 { 277 u32 size, csum; 278 char *buf, *data; 279 int ret, fd; 280 const char *msg; 281 int pos; 282 283 ret = load_xbc_file(xbc_path, &buf); 284 if (ret < 0) { 285 pr_err("Failed to load %s : %d\n", xbc_path, ret); 286 return ret; 287 } 288 size = strlen(buf) + 1; 289 csum = checksum((unsigned char *)buf, size); 290 291 /* Prepare xbc_path data */ 292 data = malloc(size + 8); 293 if (!data) 294 return -ENOMEM; 295 strcpy(data, buf); 296 *(u32 *)(data + size) = size; 297 *(u32 *)(data + size + 4) = csum; 298 299 /* Check the data format */ 300 ret = xbc_init(buf, &msg, &pos); 301 if (ret < 0) { 302 show_xbc_error(data, msg, pos); 303 free(data); 304 free(buf); 305 306 return ret; 307 } 308 printf("Apply %s to %s\n", xbc_path, path); 309 printf("\tNumber of nodes: %d\n", ret); 310 printf("\tSize: %u bytes\n", (unsigned int)size); 311 printf("\tChecksum: %d\n", (unsigned int)csum); 312 313 /* TODO: Check the options by schema */ 314 xbc_destroy_all(); 315 free(buf); 316 317 /* Remove old boot config if exists */ 318 ret = delete_xbc(path); 319 if (ret < 0) { 320 pr_err("Failed to delete previous boot config: %d\n", ret); 321 free(data); 322 return ret; 323 } 324 325 /* Apply new one */ 326 fd = open(path, O_RDWR | O_APPEND); 327 if (fd < 0) { 328 pr_err("Failed to open %s: %d\n", path, fd); 329 free(data); 330 return fd; 331 } 332 /* TODO: Ensure the @path is initramfs/initrd image */ 333 ret = write(fd, data, size + 8); 334 if (ret < 0) { 335 pr_err("Failed to apply a boot config: %d\n", ret); 336 goto out; 337 } 338 /* Write a magic word of the bootconfig */ 339 ret = write(fd, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN); 340 if (ret < 0) { 341 pr_err("Failed to apply a boot config magic: %d\n", ret); 342 goto out; 343 } 344 ret = 0; 345 out: 346 close(fd); 347 free(data); 348 349 return ret; 350 } 351 352 int usage(void) 353 { 354 printf("Usage: bootconfig [OPTIONS] <INITRD>\n" 355 " Apply, delete or show boot config to initrd.\n" 356 " Options:\n" 357 " -a <config>: Apply boot config to initrd\n" 358 " -d : Delete boot config file from initrd\n\n" 359 " If no option is given, show current applied boot config.\n"); 360 return -1; 361 } 362 363 int main(int argc, char **argv) 364 { 365 char *path = NULL; 366 char *apply = NULL; 367 bool delete = false; 368 int opt; 369 370 while ((opt = getopt(argc, argv, "hda:")) != -1) { 371 switch (opt) { 372 case 'd': 373 delete = true; 374 break; 375 case 'a': 376 apply = optarg; 377 break; 378 case 'h': 379 default: 380 return usage(); 381 } 382 } 383 384 if (apply && delete) { 385 pr_err("Error: You can not specify both -a and -d at once.\n"); 386 return usage(); 387 } 388 389 if (optind >= argc) { 390 pr_err("Error: No initrd is specified.\n"); 391 return usage(); 392 } 393 394 path = argv[optind]; 395 396 if (apply) 397 return apply_xbc(path, apply); 398 else if (delete) 399 return delete_xbc(path); 400 401 return show_xbc(path); 402 } 403