tools: bootconfig: Add bootconfig command

Add "bootconfig" command which operates the bootconfig
config-data on initrd image.

User can add/delete/verify the boot config on initrd
image using this command.

e.g.
Add a boot config to initrd image
 # bootconfig -a myboot.conf /boot/initrd.img

Remove it.
 # bootconfig -d /boot/initrd.img

Or verify (and show) it.
 # bootconfig /boot/initrd.img

Link: http://lkml.kernel.org/r/157867223582.17873.14342161849213219982.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
[ Removed extra blank line at end of bootconfig.c ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

1 files changed, 353 insertions, 0 deletions

diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c
new file mode 100644
index 000000000000..b8f174fd2a0a
--- /dev/null
+++ b/tools/bootconfig/main.c
@@ -0,0 +1,353 @@
+// 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>
+
+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] <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) {
+		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);
+}