// SPDX-License-Identifier: GPL-2.0/* * Boot config tool for initrd image */#include <stdio.h>#include <stdlib.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <unistd.h>#include <string.h>#include <errno.h> #include <linux/kernel.h>#include <linux/bootconfig.h> static int xbc_show_value(struct xbc_node *node){	const char *val;	char q;	int i = 0; 	xbc_array_for_each_value(node, val) {		if (strchr(val, '"'))			q = '\'';		else			q = '"';		printf("%c%s%c%s", q, val, q, 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));			xbc_show_value(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;	char magic[BOOTCONFIG_MAGIC_LEN];	const char *msg; 	ret = fstat(fd, &stat);	if (ret < 0)		return -errno; 	if (stat.st_size < 8 + BOOTCONFIG_MAGIC_LEN)		return 0; 	if (lseek(fd, -BOOTCONFIG_MAGIC_LEN, SEEK_END) < 0) {		pr_err("Failed to lseek: %d\n", -errno);		return -errno;	}	if (read(fd, magic, BOOTCONFIG_MAGIC_LEN) < 0)		return -errno;	/* Check the bootconfig magic bytes */	if (memcmp(magic, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN) != 0)		return 0; 	if (lseek(fd, -(8 + BOOTCONFIG_MAGIC_LEN), SEEK_END) < 0) {		pr_err("Failed 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 error  */	if (stat.st_size < size + 8 + BOOTCONFIG_MAGIC_LEN) {		pr_err("bootconfig size is too big\n");		return -E2BIG;	} 	if (lseek(fd, stat.st_size - (size + 8 + BOOTCONFIG_MAGIC_LEN),		  SEEK_SET) < 0) {		pr_err("Failed to lseek: %d\n", -errno);		return -errno;	} 	ret = load_xbc_fd(fd, buf, size);	if (ret < 0)		return ret; 	/* Wrong Checksum */	rcsum = checksum((unsigned char *)*buf, size);	if (csum != rcsum) {		pr_err("checksum error: %d != %d\n", csum, rcsum);		return -EINVAL;	} 	ret = xbc_init(*buf, &msg, NULL);	/* Wrong data */	if (ret < 0) {		pr_err("parse error: %s.\n", msg);		return ret;	} 	return size;} int show_xbc(const char *path){	int ret, fd;	char *buf = NULL; 	fd = open(path, O_RDONLY);	if (fd < 0) {		pr_err("Failed to open initrd %s: %d\n", path, fd);		return -errno;	} 	ret = load_xbc_from_initrd(fd, &buf);	if (ret < 0) {		pr_err("Failed to load a boot config from initrd: %d\n", ret);		goto out;	}	xbc_show_compact_tree();	ret = 0;out:	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) {		pr_err("Failed to open initrd %s: %d\n", path, fd);		return -errno;	} 	size = load_xbc_from_initrd(fd, &buf);	if (size < 0) {		ret = size;		pr_err("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 - BOOTCONFIG_MAGIC_LEN);		if (ret)			ret = -errno;	} /* Ignore if there is no boot config in initrd */ 	close(fd);	free(buf); 	return ret;} static void show_xbc_error(const char *data, const char *msg, int pos){	int lin = 1, col, i; 	if (pos < 0) {		pr_err("Error: %s.\n", msg);		return;	} 	/* Note that pos starts from 0 but lin and col should start from 1. */	col = pos + 1;	for (i = 0; i < pos; i++) {		if (data[i] == '\n') {			lin++;			col = pos - i;		}	}	pr_err("Parse Error: %s at %d:%d\n", msg, lin, col); } int apply_xbc(const char *path, const char *xbc_path){	u32 size, csum;	char *buf, *data;	int ret, fd;	const char *msg;	int pos; 	ret = load_xbc_file(xbc_path, &buf);	if (ret < 0) {		pr_err("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, &msg, &pos);	if (ret < 0) {		show_xbc_error(data, msg, pos);		free(data);		free(buf); 		return ret;	}	printf("Apply %s to %s\n", xbc_path, path);	printf("\tNumber of nodes: %d\n", ret);	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) {		pr_err("Failed to delete previous boot config: %d\n", ret);		free(data);		return ret;	} 	/* Apply new one */	fd = open(path, O_RDWR | O_APPEND);	if (fd < 0) {		pr_err("Failed to open %s: %d\n", path, fd);		free(data);		return fd;	}	/* TODO: Ensure the @path is initramfs/initrd image */	ret = write(fd, data, size + 8);	if (ret < 0) {		pr_err("Failed to apply a boot config: %d\n", ret);		goto out;	}	/* Write a magic word of the bootconfig */	ret = write(fd, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);	if (ret < 0) {		pr_err("Failed to apply a boot config magic: %d\n", ret);		goto out;	}	ret = 0;out:	close(fd);	free(data); 	return ret;} int usage(void){	printf("Usage: bootconfig [OPTIONS] <INITRD>\n"		" Apply, delete or show boot config to initrd.\n"		" Options:\n"		"		-a <config>: 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) {		pr_err("Error: You can not specify both -a and -d at once.\n");		return usage();	} 	if (optind >= argc) {		pr_err("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);}