linux/tools/bootconfig/main.c

395 lines
7.6 KiB
C

// 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_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;
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);
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) {
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);
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);
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);
return ret;
}
/* 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);
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) {
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);
}