linux/tools/bootconfig/main.c
Masami Hiramatsu e86843580d tools/bootconfig: Store size and checksum in footer as le32
Store the size and the checksum fields in the footer as le32
instead of u32. This will allow us to apply bootconfig to the
cross build initrd without caring the endianness.

Link: https://lkml.kernel.org/r/160583935332.547349.5897811300636587426.stgit@devnote2

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 23:22:11 -05:00

508 lines
10 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 <endian.h>
#include <linux/kernel.h>
#include <linux/bootconfig.h>
static int xbc_show_value(struct xbc_node *node, bool semicolon)
{
const char *val, *eol;
char q;
int i = 0;
eol = semicolon ? ";\n" : "\n";
xbc_array_for_each_value(node, val) {
if (strchr(val, '"'))
q = '\'';
else
q = '"';
printf("%c%s%c%s", q, val, q, node->next ? ", " : eol);
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, true);
} 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);
}
}
static void xbc_show_list(void)
{
char key[XBC_KEYLEN_MAX];
struct xbc_node *leaf;
const char *val;
int ret = 0;
xbc_for_each_key_value(leaf, val) {
ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX);
if (ret < 0)
break;
printf("%s = ", key);
if (!val || val[0] == '\0') {
printf("\"\"\n");
continue;
}
xbc_show_value(xbc_node_get_child(leaf), false);
}
}
/* Simple real checksum */
static 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
static 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 */
static 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;
}
static int pr_errno(const char *msg, int err)
{
pr_err("%s: %d\n", msg, err);
return err;
}
static 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)
return pr_errno("Failed to lseek for magic", -errno);
if (read(fd, magic, BOOTCONFIG_MAGIC_LEN) < 0)
return pr_errno("Failed to read", -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)
return pr_errno("Failed to lseek for size", -errno);
if (read(fd, &size, sizeof(u32)) < 0)
return pr_errno("Failed to read size", -errno);
size = le32toh(size);
if (read(fd, &csum, sizeof(u32)) < 0)
return pr_errno("Failed to read checksum", -errno);
csum = le32toh(csum);
/* 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)
return pr_errno("Failed to lseek", -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;
}
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);
}
static int init_xbc_with_error(char *buf, int len)
{
char *copy = strdup(buf);
const char *msg;
int ret, pos;
if (!copy)
return -ENOMEM;
ret = xbc_init(buf, &msg, &pos);
if (ret < 0)
show_xbc_error(copy, msg, pos);
free(copy);
return ret;
}
static int show_xbc(const char *path, bool list)
{
int ret, fd;
char *buf = NULL;
struct stat st;
ret = stat(path, &st);
if (ret < 0) {
ret = -errno;
pr_err("Failed to stat %s: %d\n", path, ret);
return ret;
}
fd = open(path, O_RDONLY);
if (fd < 0) {
ret = -errno;
pr_err("Failed to open initrd %s: %d\n", path, ret);
return ret;
}
ret = load_xbc_from_initrd(fd, &buf);
close(fd);
if (ret < 0) {
pr_err("Failed to load a boot config from initrd: %d\n", ret);
goto out;
}
/* Assume a bootconfig file if it is enough small */
if (ret == 0 && st.st_size <= XBC_DATA_MAX) {
ret = load_xbc_file(path, &buf);
if (ret < 0) {
pr_err("Failed to load a boot config: %d\n", ret);
goto out;
}
if (init_xbc_with_error(buf, ret) < 0)
goto out;
}
if (list)
xbc_show_list();
else
xbc_show_compact_tree();
ret = 0;
out:
free(buf);
return ret;
}
static 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) {
ret = -errno;
pr_err("Failed to open initrd %s: %d\n", path, ret);
return ret;
}
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 int apply_xbc(const char *path, const char *xbc_path)
{
char *buf, *data, *p;
size_t total_size;
struct stat stat;
const char *msg;
u32 size, csum;
int pos, pad;
int ret, fd;
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);
/* Backup the bootconfig data */
data = calloc(size + BOOTCONFIG_ALIGN +
sizeof(u32) + sizeof(u32) + BOOTCONFIG_MAGIC_LEN, 1);
if (!data)
return -ENOMEM;
memcpy(data, buf, size);
/* 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) {
ret = -errno;
pr_err("Failed to open %s: %d\n", path, ret);
free(data);
return ret;
}
/* TODO: Ensure the @path is initramfs/initrd image */
if (fstat(fd, &stat) < 0) {
pr_err("Failed to get the size of %s\n", path);
goto out;
}
/* To align up the total size to BOOTCONFIG_ALIGN, get padding size */
total_size = stat.st_size + size + sizeof(u32) * 2 + BOOTCONFIG_MAGIC_LEN;
pad = ((total_size + BOOTCONFIG_ALIGN - 1) & (~BOOTCONFIG_ALIGN_MASK)) - total_size;
size += pad;
/* Add a footer */
p = data + size;
*(u32 *)p = htole32(size);
p += sizeof(u32);
*(u32 *)p = htole32(csum);
p += sizeof(u32);
memcpy(p, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
p += BOOTCONFIG_MAGIC_LEN;
total_size = p - data;
ret = write(fd, data, total_size);
if (ret < total_size) {
if (ret < 0)
ret = -errno;
pr_err("Failed to apply a boot config: %d\n", ret);
if (ret >= 0)
goto out_rollback;
} else
ret = 0;
out:
close(fd);
free(data);
return ret;
out_rollback:
/* Map the partial write to -ENOSPC */
if (ret >= 0)
ret = -ENOSPC;
if (ftruncate(fd, stat.st_size) < 0) {
ret = -errno;
pr_err("Failed to rollback the write error: %d\n", ret);
pr_err("The initrd %s may be corrupted. Recommend to rebuild.\n", path);
}
goto out;
}
static int usage(void)
{
printf("Usage: bootconfig [OPTIONS] <INITRD>\n"
"Or bootconfig <CONFIG>\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"
" -l : list boot config in initrd or file\n\n"
" If no option is given, show the bootconfig in the given file.\n");
return -1;
}
int main(int argc, char **argv)
{
char *path = NULL;
char *apply = NULL;
bool delete = false, list = false;
int opt;
while ((opt = getopt(argc, argv, "hda:l")) != -1) {
switch (opt) {
case 'd':
delete = true;
break;
case 'a':
apply = optarg;
break;
case 'l':
list = true;
break;
case 'h':
default:
return usage();
}
}
if ((apply && delete) || (delete && list) || (apply && list)) {
pr_err("Error: You can give one of -a, -d or -l 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, list);
}