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