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/* vi: set sw=4 ts=4: */
/*
* chattr.c - Change file attributes on an ext2 file system
*
* Copyright (C) 1993, 1994 Remy Card <card@masi.ibp.fr>
* Laboratoire MASI, Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* This file can be redistributed under the terms of the GNU General
* Public License
*/
//config:config CHATTR
//config: bool "chattr (3.2 kb)"
//config: default y
//config: help
//config: chattr changes the file attributes on a second extended file system.
//applet:IF_CHATTR(APPLET(chattr, BB_DIR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_CHATTR) += chattr.o e2fs_lib.o
//usage:#define chattr_trivial_usage
//usage: "[-R] [-v VERSION] [-+=AacDdijsStTu] FILE..."
//usage:#define chattr_full_usage "\n\n"
//usage: "Change ext2 file attributes\n"
//usage: "\n -R Recurse"
//usage: "\n -v VER Set version/generation number"
//-V, -f accepted but ignored
//usage: "\nModifiers:"
//usage: "\n -,+,= Remove/add/set attributes"
//usage: "\nAttributes:"
//usage: "\n A Don't track atime"
//usage: "\n a Append mode only"
//usage: "\n c Enable compress"
//usage: "\n D Write dir contents synchronously"
//usage: "\n d Don't backup with dump"
//usage: "\n i Cannot be modified (immutable)"
//usage: "\n j Write all data to journal first"
//usage: "\n s Zero disk storage when deleted"
//usage: "\n S Write synchronously"
//usage: "\n t Disable tail-merging of partial blocks with other files"
//usage: "\n u Allow file to be undeleted"
#include "libbb.h"
#include "e2fs_lib.h"
#define OPT_ADD 1
#define OPT_REM 2
#define OPT_SET 4
#define OPT_SET_VER 8
struct globals {
unsigned long version;
unsigned long af;
unsigned long rf;
int flags;
smallint recursive;
};
static unsigned long get_flag(char c)
{
const char *fp = strchr(e2attr_flags_sname_chattr, c);
if (fp)
return e2attr_flags_value_chattr[fp - e2attr_flags_sname_chattr];
bb_show_usage();
}
static char** decode_arg(char **argv, struct globals *gp)
{
unsigned long *fl;
const char *arg = *argv;
char opt = *arg;
fl = &gp->af;
if (opt == '-') {
gp->flags |= OPT_REM;
fl = &gp->rf;
} else if (opt == '+') {
gp->flags |= OPT_ADD;
} else { /* if (opt == '=') */
gp->flags |= OPT_SET;
}
while (*++arg) {
if (opt == '-') {
//e2fsprogs-1.43.1 accepts:
// "-RRR", "-RRRv VER" and even "-ARRRva VER" and "-vvv V1 V2 V3"
// but not "-vVER".
// IOW: options are parsed as part of "remove attrs" strings,
// if "v" is seen, next argv[] is VER, even if more opts/attrs follow in this argv[]!
if (*arg == 'R') {
gp->recursive = 1;
continue;
}
if (*arg == 'V') {
/*"verbose and print program version" (nop for now) */;
continue;
}
if (*arg == 'f') {
/*"suppress most error messages" (nop) */;
continue;
}
if (*arg == 'v') {
if (!*++argv)
bb_show_usage();
gp->version = xatoul(*argv);
gp->flags |= OPT_SET_VER;
continue;
}
//TODO: "-p PROJECT_NUM" ?
/* not a known option, try as an attribute */
}
*fl |= get_flag(*arg);
}
return argv;
}
static void change_attributes(const char *name, struct globals *gp);
static int FAST_FUNC chattr_dir_proc(const char *dir_name, struct dirent *de, void *gp)
{
char *path = concat_subpath_file(dir_name, de->d_name);
/* path is NULL if de->d_name is "." or "..", else... */
if (path) {
change_attributes(path, gp);
free(path);
}
return 0;
}
static void change_attributes(const char *name, struct globals *gp)
{
unsigned long fsflags;
struct stat st;
if (lstat(name, &st) != 0) {
bb_perror_msg("stat %s", name);
return;
}
if (S_ISLNK(st.st_mode) && gp->recursive)
return;
/* Don't try to open device files, fifos etc. We probably
* ought to display an error if the file was explicitly given
* on the command line (whether or not recursive was
* requested). */
if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode) && !S_ISDIR(st.st_mode))
return;
if (gp->flags & OPT_SET_VER)
if (fsetversion(name, gp->version) != 0)
bb_perror_msg("setting version on %s", name);
if (gp->flags & OPT_SET) {
fsflags = gp->af;
} else {
if (fgetflags(name, &fsflags) != 0) {
bb_perror_msg("reading flags on %s", name);
goto skip_setflags;
}
/*if (gp->flags & OPT_REM) - not needed, rf is zero otherwise */
fsflags &= ~gp->rf;
/*if (gp->flags & OPT_ADD) - not needed, af is zero otherwise */
fsflags |= gp->af;
// What is this? And why it's not done for SET case?
if (!S_ISDIR(st.st_mode))
fsflags &= ~EXT2_DIRSYNC_FL;
}
if (fsetflags(name, fsflags) != 0)
bb_perror_msg("setting flags on %s", name);
skip_setflags:
if (gp->recursive && S_ISDIR(st.st_mode))
iterate_on_dir(name, chattr_dir_proc, gp);
}
int chattr_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int chattr_main(int argc UNUSED_PARAM, char **argv)
{
struct globals g;
memset(&g, 0, sizeof(g));
/* parse the args */
for (;;) {
char *arg = *++argv;
if (!arg)
bb_show_usage();
if (arg[0] != '-' && arg[0] != '+' && arg[0] != '=')
break;
argv = decode_arg(argv, &g);
}
/* note: on loop exit, remaining argv[] is never empty */
/* run sanity checks on all the arguments given us */
if ((g.flags & OPT_SET) && (g.flags & (OPT_ADD|OPT_REM)))
bb_error_msg_and_die("= is incompatible with - and +");
if (g.rf & g.af)
bb_error_msg_and_die("can't set and unset a flag");
if (!g.flags)
bb_error_msg_and_die("must use '-v', =, - or +");
/* now run chattr on all the files passed to us */
do change_attributes(*argv, &g); while (*++argv);
return EXIT_SUCCESS;
}
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