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>
diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c
new file mode 100644
index 0000000..b8f174f
--- /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);
+}