// SPDX-License-Identifier: GPL-2.0 /* * Boot config tool for initrd image */ #include #include #include #include #include #include #include #include #include #include int pr_output = 1; static int xbc_show_array(struct xbc_node *node) { const char *val; int i = 0; xbc_array_for_each_value(node, val) { printf("\"%s\"%s", val, node->next ? ", " : ";\n"); i++; } return i; } static void xbc_show_compact_tree(void) { struct xbc_node *node, *cnode; int depth = 0, i; node = xbc_root_node(); while (node && xbc_node_is_key(node)) { for (i = 0; i < depth; i++) printf("\t"); cnode = xbc_node_get_child(node); while (cnode && xbc_node_is_key(cnode) && !cnode->next) { printf("%s.", xbc_node_get_data(node)); node = cnode; cnode = xbc_node_get_child(node); } if (cnode && xbc_node_is_key(cnode)) { printf("%s {\n", xbc_node_get_data(node)); depth++; node = cnode; continue; } else if (cnode && xbc_node_is_value(cnode)) { printf("%s = ", xbc_node_get_data(node)); if (cnode->next) xbc_show_array(cnode); else printf("\"%s\";\n", xbc_node_get_data(cnode)); } else { printf("%s;\n", xbc_node_get_data(node)); } if (node->next) { node = xbc_node_get_next(node); continue; } while (!node->next) { node = xbc_node_get_parent(node); if (!node) return; if (!xbc_node_get_child(node)->next) continue; depth--; for (i = 0; i < depth; i++) printf("\t"); printf("}\n"); } node = xbc_node_get_next(node); } } /* Simple real checksum */ int checksum(unsigned char *buf, int len) { int i, sum = 0; for (i = 0; i < len; i++) sum += buf[i]; return sum; } #define PAGE_SIZE 4096 int load_xbc_fd(int fd, char **buf, int size) { int ret; *buf = malloc(size + 1); if (!*buf) return -ENOMEM; ret = read(fd, *buf, size); if (ret < 0) return -errno; (*buf)[size] = '\0'; return ret; } /* Return the read size or -errno */ int load_xbc_file(const char *path, char **buf) { struct stat stat; int fd, ret; fd = open(path, O_RDONLY); if (fd < 0) return -errno; ret = fstat(fd, &stat); if (ret < 0) return -errno; ret = load_xbc_fd(fd, buf, stat.st_size); close(fd); return ret; } int load_xbc_from_initrd(int fd, char **buf) { struct stat stat; int ret; u32 size = 0, csum = 0, rcsum; ret = fstat(fd, &stat); if (ret < 0) return -errno; if (stat.st_size < 8) return 0; if (lseek(fd, -8, SEEK_END) < 0) { printf("Faile to lseek: %d\n", -errno); return -errno; } if (read(fd, &size, sizeof(u32)) < 0) return -errno; if (read(fd, &csum, sizeof(u32)) < 0) return -errno; /* Wrong size, maybe no boot config here */ if (stat.st_size < size + 8) return 0; if (lseek(fd, stat.st_size - 8 - size, SEEK_SET) < 0) { printf("Faile to lseek: %d\n", -errno); return -errno; } ret = load_xbc_fd(fd, buf, size); if (ret < 0) return ret; /* Wrong Checksum, maybe no boot config here */ rcsum = checksum((unsigned char *)*buf, size); if (csum != rcsum) { printf("checksum error: %d != %d\n", csum, rcsum); return 0; } ret = xbc_init(*buf); /* Wrong data, maybe no boot config here */ if (ret < 0) return 0; return size; } int show_xbc(const char *path) { int ret, fd; char *buf = NULL; fd = open(path, O_RDONLY); if (fd < 0) { printf("Failed to open initrd %s: %d\n", path, fd); return -errno; } ret = load_xbc_from_initrd(fd, &buf); if (ret < 0) printf("Failed to load a boot config from initrd: %d\n", ret); else xbc_show_compact_tree(); close(fd); free(buf); return ret; } int delete_xbc(const char *path) { struct stat stat; int ret = 0, fd, size; char *buf = NULL; fd = open(path, O_RDWR); if (fd < 0) { printf("Failed to open initrd %s: %d\n", path, fd); return -errno; } /* * Suppress error messages in xbc_init() because it can be just a * data which concidentally matches the size and checksum footer. */ pr_output = 0; size = load_xbc_from_initrd(fd, &buf); pr_output = 1; if (size < 0) { ret = size; printf("Failed to load a boot config from initrd: %d\n", ret); } else if (size > 0) { ret = fstat(fd, &stat); if (!ret) ret = ftruncate(fd, stat.st_size - size - 8); if (ret) ret = -errno; } /* Ignore if there is no boot config in initrd */ close(fd); free(buf); return ret; } int apply_xbc(const char *path, const char *xbc_path) { u32 size, csum; char *buf, *data; int ret, fd; ret = load_xbc_file(xbc_path, &buf); if (ret < 0) { printf("Failed to load %s : %d\n", xbc_path, ret); return ret; } size = strlen(buf) + 1; csum = checksum((unsigned char *)buf, size); /* Prepare xbc_path data */ data = malloc(size + 8); if (!data) return -ENOMEM; strcpy(data, buf); *(u32 *)(data + size) = size; *(u32 *)(data + size + 4) = csum; /* Check the data format */ ret = xbc_init(buf); if (ret < 0) { printf("Failed to parse %s: %d\n", xbc_path, ret); free(data); free(buf); return ret; } printf("Apply %s to %s\n", xbc_path, path); printf("\tSize: %u bytes\n", (unsigned int)size); printf("\tChecksum: %d\n", (unsigned int)csum); /* TODO: Check the options by schema */ xbc_destroy_all(); free(buf); /* Remove old boot config if exists */ ret = delete_xbc(path); if (ret < 0) { printf("Failed to delete previous boot config: %d\n", ret); return ret; } /* Apply new one */ fd = open(path, O_RDWR | O_APPEND); if (fd < 0) { printf("Failed to open %s: %d\n", path, fd); return fd; } /* TODO: Ensure the @path is initramfs/initrd image */ ret = write(fd, data, size + 8); if (ret < 0) { printf("Failed to apply a boot config: %d\n", ret); return ret; } close(fd); free(data); return 0; } int usage(void) { printf("Usage: bootconfig [OPTIONS] \n" " Apply, delete or show boot config to initrd.\n" " Options:\n" " -a : Apply boot config to initrd\n" " -d : Delete boot config file from initrd\n\n" " If no option is given, show current applied boot config.\n"); return -1; } int main(int argc, char **argv) { char *path = NULL; char *apply = NULL; bool delete = false; int opt; while ((opt = getopt(argc, argv, "hda:")) != -1) { switch (opt) { case 'd': delete = true; break; case 'a': apply = optarg; break; case 'h': default: return usage(); } } if (apply && delete) { printf("Error: You can not specify both -a and -d at once.\n"); return usage(); } if (optind >= argc) { printf("Error: No initrd is specified.\n"); return usage(); } path = argv[optind]; if (apply) return apply_xbc(path, apply); else if (delete) return delete_xbc(path); return show_xbc(path); }