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]; 133 134 ret = fstat(fd, &stat); 135 if (ret < 0) 136 return -errno; 137 138 if (stat.st_size < 8 + BOOTCONFIG_MAGIC_LEN) 139 return 0; 140 141 if (lseek(fd, -BOOTCONFIG_MAGIC_LEN, SEEK_END) < 0) { 142 pr_err("Failed to lseek: %d\n", -errno); 143 return -errno; 144 } 145 if (read(fd, magic, BOOTCONFIG_MAGIC_LEN) < 0) 146 return -errno; 147 /* Check the bootconfig magic bytes */ 148 if (memcmp(magic, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN) != 0) 149 return 0; 150 151 if (lseek(fd, -(8 + BOOTCONFIG_MAGIC_LEN), SEEK_END) < 0) { 152 pr_err("Failed to lseek: %d\n", -errno); 153 return -errno; 154 } 155 156 if (read(fd, &size, sizeof(u32)) < 0) 157 return -errno; 158 159 if (read(fd, &csum, sizeof(u32)) < 0) 160 return -errno; 161 162 /* Wrong size error */ 163 if (stat.st_size < size + 8 + BOOTCONFIG_MAGIC_LEN) { 164 pr_err("bootconfig size is too big\n"); 165 return -E2BIG; 166 } 167 168 if (lseek(fd, stat.st_size - (size + 8 + BOOTCONFIG_MAGIC_LEN), 169 SEEK_SET) < 0) { 170 pr_err("Failed to lseek: %d\n", -errno); 171 return -errno; 172 } 173 174 ret = load_xbc_fd(fd, buf, size); 175 if (ret < 0) 176 return ret; 177 178 /* Wrong Checksum */ 179 rcsum = checksum((unsigned char *)*buf, size); 180 if (csum != rcsum) { 181 pr_err("checksum error: %d != %d\n", csum, rcsum); 182 return -EINVAL; 183 } 184 185 ret = xbc_init(*buf); 186 /* Wrong data */ 187 if (ret < 0) 188 return ret; 189 190 return size; 191 } 192 193 int show_xbc(const char *path) 194 { 195 int ret, fd; 196 char *buf = NULL; 197 198 fd = open(path, O_RDONLY); 199 if (fd < 0) { 200 pr_err("Failed to open initrd %s: %d\n", path, fd); 201 return -errno; 202 } 203 204 ret = load_xbc_from_initrd(fd, &buf); 205 if (ret < 0) 206 pr_err("Failed to load a boot config from initrd: %d\n", ret); 207 else 208 xbc_show_compact_tree(); 209 210 close(fd); 211 free(buf); 212 213 return ret; 214 } 215 216 int delete_xbc(const char *path) 217 { 218 struct stat stat; 219 int ret = 0, fd, size; 220 char *buf = NULL; 221 222 fd = open(path, O_RDWR); 223 if (fd < 0) { 224 pr_err("Failed to open initrd %s: %d\n", path, fd); 225 return -errno; 226 } 227 228 size = load_xbc_from_initrd(fd, &buf); 229 if (size < 0) { 230 ret = size; 231 pr_err("Failed to load a boot config from initrd: %d\n", ret); 232 } else if (size > 0) { 233 ret = fstat(fd, &stat); 234 if (!ret) 235 ret = ftruncate(fd, stat.st_size 236 - size - 8 - BOOTCONFIG_MAGIC_LEN); 237 if (ret) 238 ret = -errno; 239 } /* Ignore if there is no boot config in initrd */ 240 241 close(fd); 242 free(buf); 243 244 return ret; 245 } 246 247 int apply_xbc(const char *path, const char *xbc_path) 248 { 249 u32 size, csum; 250 char *buf, *data; 251 int ret, fd; 252 253 ret = load_xbc_file(xbc_path, &buf); 254 if (ret < 0) { 255 pr_err("Failed to load %s : %d\n", xbc_path, ret); 256 return ret; 257 } 258 size = strlen(buf) + 1; 259 csum = checksum((unsigned char *)buf, size); 260 261 /* Prepare xbc_path data */ 262 data = malloc(size + 8); 263 if (!data) 264 return -ENOMEM; 265 strcpy(data, buf); 266 *(u32 *)(data + size) = size; 267 *(u32 *)(data + size + 4) = csum; 268 269 /* Check the data format */ 270 ret = xbc_init(buf); 271 if (ret < 0) { 272 pr_err("Failed to parse %s: %d\n", xbc_path, ret); 273 free(data); 274 free(buf); 275 return ret; 276 } 277 printf("Apply %s to %s\n", xbc_path, path); 278 printf("\tNumber of nodes: %d\n", ret); 279 printf("\tSize: %u bytes\n", (unsigned int)size); 280 printf("\tChecksum: %d\n", (unsigned int)csum); 281 282 /* TODO: Check the options by schema */ 283 xbc_destroy_all(); 284 free(buf); 285 286 /* Remove old boot config if exists */ 287 ret = delete_xbc(path); 288 if (ret < 0) { 289 pr_err("Failed to delete previous boot config: %d\n", ret); 290 return ret; 291 } 292 293 /* Apply new one */ 294 fd = open(path, O_RDWR | O_APPEND); 295 if (fd < 0) { 296 pr_err("Failed to open %s: %d\n", path, fd); 297 return fd; 298 } 299 /* TODO: Ensure the @path is initramfs/initrd image */ 300 ret = write(fd, data, size + 8); 301 if (ret < 0) { 302 pr_err("Failed to apply a boot config: %d\n", ret); 303 return ret; 304 } 305 /* Write a magic word of the bootconfig */ 306 ret = write(fd, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN); 307 if (ret < 0) { 308 pr_err("Failed to apply a boot config magic: %d\n", ret); 309 return ret; 310 } 311 close(fd); 312 free(data); 313 314 return 0; 315 } 316 317 int usage(void) 318 { 319 printf("Usage: bootconfig [OPTIONS] <INITRD>\n" 320 " Apply, delete or show boot config to initrd.\n" 321 " Options:\n" 322 " -a <config>: Apply boot config to initrd\n" 323 " -d : Delete boot config file from initrd\n\n" 324 " If no option is given, show current applied boot config.\n"); 325 return -1; 326 } 327 328 int main(int argc, char **argv) 329 { 330 char *path = NULL; 331 char *apply = NULL; 332 bool delete = false; 333 int opt; 334 335 while ((opt = getopt(argc, argv, "hda:")) != -1) { 336 switch (opt) { 337 case 'd': 338 delete = true; 339 break; 340 case 'a': 341 apply = optarg; 342 break; 343 case 'h': 344 default: 345 return usage(); 346 } 347 } 348 349 if (apply && delete) { 350 pr_err("Error: You can not specify both -a and -d at once.\n"); 351 return usage(); 352 } 353 354 if (optind >= argc) { 355 pr_err("Error: No initrd is specified.\n"); 356 return usage(); 357 } 358 359 path = argv[optind]; 360 361 if (apply) 362 return apply_xbc(path, apply); 363 else if (delete) 364 return delete_xbc(path); 365 366 return show_xbc(path); 367 } 368