e2fsprogs/debugfs/setsuper.c

/*
 * setsuper.c --- set a superblock value
 */

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include <fcntl.h>
#include <utime.h>

#include "debugfs.h"

static struct ext2_super_block set_sb;

struct super_set_info {
	const char	*name;
	void	*ptr;
	int	size;
	errcode_t (*func)(struct super_set_info *info, char *arg);
};

static errcode_t parse_uint(struct super_set_info *info, char *arg);
static errcode_t parse_int(struct super_set_info *info, char *arg);
static errcode_t parse_string(struct super_set_info *info, char *arg);

static struct super_set_info super_fields[] = {
	{ "inodes_count", &set_sb.s_inodes_count, 4, parse_uint },
	{ "blocks_count", &set_sb.s_blocks_count, 4, parse_uint },
	{ "r_blocks_count", &set_sb.s_r_blocks_count, 4, parse_uint },
	{ "free_blocks_count", &set_sb.s_free_blocks_count, 4, parse_uint },
	{ "free_inodes_count", &set_sb.s_free_inodes_count, 4, parse_uint },
	{ "first_data_block", &set_sb.s_first_data_block, 4, parse_uint },
	{ "log_block_size", &set_sb.s_log_block_size, 4, parse_uint },
	{ "log_frag_size", &set_sb.s_log_frag_size, 4, parse_int },
	{ "blocks_per_group", &set_sb.s_blocks_per_group, 4, parse_uint },
	{ "frags_per_group", &set_sb.s_frags_per_group, 4, parse_uint },
	{ "inodes_per_group", &set_sb.s_inodes_per_group, 4, parse_uint },
	/* s_mtime (time_t) */
	/* s_wtime (time_t) */
	{ "mnt_count", &set_sb.s_mnt_count, 2, parse_uint },
	{ "max_mnt_count", &set_sb.s_max_mnt_count, 2, parse_int },
	/* s_magic */
	{ "state", &set_sb.s_state, 2, parse_uint },
	{ "errors", &set_sb.s_errors, 2, parse_uint },
	{ "minor_rev_level", &set_sb.s_minor_rev_level, 2, parse_uint },
	/* s_lastcheck (time_t) */
	{ "checkinterval", &set_sb.s_checkinterval, 4, parse_uint },
	{ "creator_os", &set_sb.s_creator_os, 4, parse_uint },
	{ "rev_level", &set_sb.s_rev_level, 4, parse_uint },
	{ "def_resuid", &set_sb.s_def_resuid, 2, parse_uint },
	{ "def_resgid", &set_sb.s_def_resgid, 2, parse_uint },
	{ "first_ino", &set_sb.s_first_ino, 4, parse_uint },
	{ "inode_size", &set_sb.s_inode_size, 2, parse_uint },
	{ "block_group_nr", &set_sb.s_block_group_nr, 2, parse_uint },
	{ "feature_compat", &set_sb.s_feature_compat, 4, parse_uint },
	{ "feature_incompat", &set_sb.s_feature_incompat, 4, parse_uint },
	{ "feature_ro_compat", &set_sb.s_feature_ro_compat, 4, parse_uint }, 
	/* __u8	s_uuid[16]; */
	{ "volume_name",  &set_sb.s_volume_name, 16, parse_string },
	{ "last_mounted",  &set_sb.s_last_mounted, 64, parse_string },
	{ "algorithm_usage_bitmap", &set_sb.s_algorithm_usage_bitmap, 
		  4, parse_uint },
	{ "prealloc_blocks", &set_sb.s_prealloc_blocks, 1, parse_uint },
	{ "prealloc_dir_blocks", &set_sb.s_prealloc_dir_blocks, 1,
		  parse_uint },
	/* s_padding1 */
	/* s_journal_uuid */
	{ "journal_inum", &set_sb.s_journal_inum, 4, parse_uint },
	{ "journal_dev", &set_sb.s_journal_dev, 4, parse_uint },
	{ "last_orphan", &set_sb.s_last_orphan, 4, parse_uint },
	
	{ 0, 0, 0, 0 }
};

static struct super_set_info *find_field(char *field)
{
	struct super_set_info *ss;

	if (strncmp(field, "s_", 2) == 0)
		field += 2;
	for (ss = super_fields ; ss->name ; ss++) {
		if (strcmp(ss->name, field) == 0)
			return ss;
	}
	return NULL;
}

static errcode_t parse_uint(struct super_set_info *info, char *arg)
{
	unsigned long	num;
	char *tmp;
	__u32	*ptr32;
	__u16	*ptr16;
	__u8	*ptr8;

	num = strtoul(arg, &tmp, 0);
	if (*tmp) {
		fprintf(stderr, "Couldn't parse '%s' for field %s.\n",
			arg, info->name);
		return EINVAL;
	}
	switch (info->size) {
	case 4:
		ptr32 = (__u32 *) info->ptr;
		*ptr32 = num;
		break;
	case 2:
		ptr16 = (__u16 *) info->ptr;
		*ptr16 = num;
		break;
	case 1:
		ptr8 = (__u8 *) info->ptr;
		*ptr8 = num;
		break;
	}
	return 0;
}

static errcode_t parse_int(struct super_set_info *info, char *arg)
{
	long	num;
	char *tmp;
	__s32	*ptr32;
	__s16	*ptr16;
	__s8	*ptr8;

	num = strtol(arg, &tmp, 0);
	if (*tmp) {
		fprintf(stderr, "Couldn't parse '%s' for field %s.\n",
			arg, info->name);
		return EINVAL;
	}
	switch (info->size) {
	case 4:
		ptr32 = (__s32 *) info->ptr;
		*ptr32 = num;
		break;
	case 2:
		ptr16 = (__s16 *) info->ptr;
		*ptr16 = num;
		break;
	case 1:
		ptr8 = (__s8 *) info->ptr;
		*ptr8 = num;
		break;
	}
	return 0;
}

static errcode_t parse_string(struct super_set_info *info, char *arg)
{
	char	*cp = (char *) info->ptr;

	if (strlen(arg) >= info->size) {
		fprintf(stderr, "Error maximum size for %s is %d.\n",
			info->name, info->size);
		return EINVAL;
	}
	strcpy(cp, arg);
	return 0;
}

void do_set_super(int argc, char *argv[])
{
	static struct super_set_info *ss;
	
	if (check_fs_open(argv[0]))
		return;

	if (argc != 3) {
		com_err(argv[0], 0, "Usage: set_super <field> <value>");
		return;
	}

	if (check_fs_read_write(argv[0]))
		return;
	
	if ((ss = find_field(argv[1])) == 0) {
		com_err(argv[0], 0, "invalid field specifier: %s", argv[1]);
		return;
	}
	set_sb = *current_fs->super;
	if (ss->func(ss, argv[2]) == 0) {
		*current_fs->super = set_sb;
		ext2fs_mark_super_dirty(current_fs);
	}
}